linux/fs/relayfs/inode.c

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[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
/*
* VFS-related code for RelayFS, a high-speed data relay filesystem.
*
* Copyright (C) 2003-2005 - Tom Zanussi <zanussi@us.ibm.com>, IBM Corp
* Copyright (C) 2003-2005 - Karim Yaghmour <karim@opersys.com>
*
* Based on ramfs, Copyright (C) 2002 - Linus Torvalds
*
* This file is released under the GPL.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/namei.h>
#include <linux/poll.h>
#include <linux/relayfs_fs.h>
#include "relay.h"
#include "buffers.h"
#define RELAYFS_MAGIC 0xF0B4A981
static struct vfsmount * relayfs_mount;
static int relayfs_mount_count;
static struct backing_dev_info relayfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
};
static struct inode *relayfs_get_inode(struct super_block *sb,
int mode,
struct file_operations *fops,
[PATCH] relayfs: decouple buffer creation from inode creation The patch series implementa or fixes 3 things that were specifically requested or suggested by relayfs users: - support for non-relay files (patches 1-6) Currently, the relayfs API only supports the creation of directories (relayfs_create_dir()) and relay files (relay_open()). These patches adds support for non-relay files (relayfs_create_file()). This is so relayfs applications can create 'control files' in relayfs itself rather than in /proc or via a netlink channel, as is currently done in the relay-app examples. Basically what this amounts to is exporting relayfs_create_file() with an additional file_ops param that clients can use to supply file operations for their own special-purpose files in relayfs. - make exported relay file ops useful (patches 7-8) The relayfs relay_file_operations have always been exported, the intent being to make it possible to create relay files in other filesystems such as debugfs. The problem, though, is that currently the file operations are too tightly coupled to relayfs to actually be used for this purpose. This patch fixes that by adding a couple of callback functions that allow a client to hook into relay_open()/close() and supply the files that will be used to represent the channel buffers; the default implementation if no callbacks are defined is to create the files in relayfs. - add an option to create global relay buffer (patches 9-10) The file creation callback also supplies an optional param, is_global, that can be used by clients to create a single global relayfs buffer instead of the default per-cpu buffers. This was suggested as being useful for certain debugging applications where it's more convenient to be able to get all the data from a single channel without having to go to the bother of dealing with per-cpu files. - cleanup, some renaming and Documentation updates (patches 11-12) There were several comments that the use of netlink in the example code was non-intuitive and in fact the whole relay-app business was needlessly confusing. Based on that feedback, the example code has been completely converted over to relayfs control files as supported by this patch, and have also been made completely self-contained. The converted examples along with a couple of new examples that demonstrate using exported relay files can be found in relay-apps tarball: http://prdownloads.sourceforge.net/relayfs/relay-apps-0.9.tar.gz?download This patch: Separate buffer create/destroy from inode create/destroy. We want to be able to associate other data and not just relay buffers with inodes. Buffer create/destroy is moved out of inode.c and into relayfs core code. Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:02:23 +00:00
void *data)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
struct inode *inode;
inode = new_inode(sb);
[PATCH] relayfs: decouple buffer creation from inode creation The patch series implementa or fixes 3 things that were specifically requested or suggested by relayfs users: - support for non-relay files (patches 1-6) Currently, the relayfs API only supports the creation of directories (relayfs_create_dir()) and relay files (relay_open()). These patches adds support for non-relay files (relayfs_create_file()). This is so relayfs applications can create 'control files' in relayfs itself rather than in /proc or via a netlink channel, as is currently done in the relay-app examples. Basically what this amounts to is exporting relayfs_create_file() with an additional file_ops param that clients can use to supply file operations for their own special-purpose files in relayfs. - make exported relay file ops useful (patches 7-8) The relayfs relay_file_operations have always been exported, the intent being to make it possible to create relay files in other filesystems such as debugfs. The problem, though, is that currently the file operations are too tightly coupled to relayfs to actually be used for this purpose. This patch fixes that by adding a couple of callback functions that allow a client to hook into relay_open()/close() and supply the files that will be used to represent the channel buffers; the default implementation if no callbacks are defined is to create the files in relayfs. - add an option to create global relay buffer (patches 9-10) The file creation callback also supplies an optional param, is_global, that can be used by clients to create a single global relayfs buffer instead of the default per-cpu buffers. This was suggested as being useful for certain debugging applications where it's more convenient to be able to get all the data from a single channel without having to go to the bother of dealing with per-cpu files. - cleanup, some renaming and Documentation updates (patches 11-12) There were several comments that the use of netlink in the example code was non-intuitive and in fact the whole relay-app business was needlessly confusing. Based on that feedback, the example code has been completely converted over to relayfs control files as supported by this patch, and have also been made completely self-contained. The converted examples along with a couple of new examples that demonstrate using exported relay files can be found in relay-apps tarball: http://prdownloads.sourceforge.net/relayfs/relay-apps-0.9.tar.gz?download This patch: Separate buffer create/destroy from inode create/destroy. We want to be able to associate other data and not just relay buffers with inodes. Buffer create/destroy is moved out of inode.c and into relayfs core code. Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:02:23 +00:00
if (!inode)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
return NULL;
inode->i_mode = mode;
inode->i_uid = 0;
inode->i_gid = 0;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_mapping->backing_dev_info = &relayfs_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
switch (mode & S_IFMT) {
case S_IFREG:
inode->i_fop = fops;
if (data)
inode->u.generic_ip = data;
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
break;
case S_IFDIR:
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inode->i_nlink++;
break;
default:
break;
}
return inode;
}
/**
* relayfs_create_entry - create a relayfs directory or file
* @name: the name of the file to create
* @parent: parent directory
* @mode: mode
* @fops: file operations to use for the file
[PATCH] relayfs: decouple buffer creation from inode creation The patch series implementa or fixes 3 things that were specifically requested or suggested by relayfs users: - support for non-relay files (patches 1-6) Currently, the relayfs API only supports the creation of directories (relayfs_create_dir()) and relay files (relay_open()). These patches adds support for non-relay files (relayfs_create_file()). This is so relayfs applications can create 'control files' in relayfs itself rather than in /proc or via a netlink channel, as is currently done in the relay-app examples. Basically what this amounts to is exporting relayfs_create_file() with an additional file_ops param that clients can use to supply file operations for their own special-purpose files in relayfs. - make exported relay file ops useful (patches 7-8) The relayfs relay_file_operations have always been exported, the intent being to make it possible to create relay files in other filesystems such as debugfs. The problem, though, is that currently the file operations are too tightly coupled to relayfs to actually be used for this purpose. This patch fixes that by adding a couple of callback functions that allow a client to hook into relay_open()/close() and supply the files that will be used to represent the channel buffers; the default implementation if no callbacks are defined is to create the files in relayfs. - add an option to create global relay buffer (patches 9-10) The file creation callback also supplies an optional param, is_global, that can be used by clients to create a single global relayfs buffer instead of the default per-cpu buffers. This was suggested as being useful for certain debugging applications where it's more convenient to be able to get all the data from a single channel without having to go to the bother of dealing with per-cpu files. - cleanup, some renaming and Documentation updates (patches 11-12) There were several comments that the use of netlink in the example code was non-intuitive and in fact the whole relay-app business was needlessly confusing. Based on that feedback, the example code has been completely converted over to relayfs control files as supported by this patch, and have also been made completely self-contained. The converted examples along with a couple of new examples that demonstrate using exported relay files can be found in relay-apps tarball: http://prdownloads.sourceforge.net/relayfs/relay-apps-0.9.tar.gz?download This patch: Separate buffer create/destroy from inode create/destroy. We want to be able to associate other data and not just relay buffers with inodes. Buffer create/destroy is moved out of inode.c and into relayfs core code. Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:02:23 +00:00
* @data: user-associated data for this file
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
*
* Returns the new dentry, NULL on failure
*
* Creates a file or directory with the specifed permissions.
*/
static struct dentry *relayfs_create_entry(const char *name,
struct dentry *parent,
int mode,
struct file_operations *fops,
[PATCH] relayfs: decouple buffer creation from inode creation The patch series implementa or fixes 3 things that were specifically requested or suggested by relayfs users: - support for non-relay files (patches 1-6) Currently, the relayfs API only supports the creation of directories (relayfs_create_dir()) and relay files (relay_open()). These patches adds support for non-relay files (relayfs_create_file()). This is so relayfs applications can create 'control files' in relayfs itself rather than in /proc or via a netlink channel, as is currently done in the relay-app examples. Basically what this amounts to is exporting relayfs_create_file() with an additional file_ops param that clients can use to supply file operations for their own special-purpose files in relayfs. - make exported relay file ops useful (patches 7-8) The relayfs relay_file_operations have always been exported, the intent being to make it possible to create relay files in other filesystems such as debugfs. The problem, though, is that currently the file operations are too tightly coupled to relayfs to actually be used for this purpose. This patch fixes that by adding a couple of callback functions that allow a client to hook into relay_open()/close() and supply the files that will be used to represent the channel buffers; the default implementation if no callbacks are defined is to create the files in relayfs. - add an option to create global relay buffer (patches 9-10) The file creation callback also supplies an optional param, is_global, that can be used by clients to create a single global relayfs buffer instead of the default per-cpu buffers. This was suggested as being useful for certain debugging applications where it's more convenient to be able to get all the data from a single channel without having to go to the bother of dealing with per-cpu files. - cleanup, some renaming and Documentation updates (patches 11-12) There were several comments that the use of netlink in the example code was non-intuitive and in fact the whole relay-app business was needlessly confusing. Based on that feedback, the example code has been completely converted over to relayfs control files as supported by this patch, and have also been made completely self-contained. The converted examples along with a couple of new examples that demonstrate using exported relay files can be found in relay-apps tarball: http://prdownloads.sourceforge.net/relayfs/relay-apps-0.9.tar.gz?download This patch: Separate buffer create/destroy from inode create/destroy. We want to be able to associate other data and not just relay buffers with inodes. Buffer create/destroy is moved out of inode.c and into relayfs core code. Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:02:23 +00:00
void *data)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
struct dentry *d;
struct inode *inode;
int error = 0;
BUG_ON(!name || !(S_ISREG(mode) || S_ISDIR(mode)));
error = simple_pin_fs("relayfs", &relayfs_mount, &relayfs_mount_count);
if (error) {
printk(KERN_ERR "Couldn't mount relayfs: errcode %d\n", error);
return NULL;
}
if (!parent && relayfs_mount && relayfs_mount->mnt_sb)
parent = relayfs_mount->mnt_sb->s_root;
if (!parent) {
simple_release_fs(&relayfs_mount, &relayfs_mount_count);
return NULL;
}
parent = dget(parent);
mutex_lock(&parent->d_inode->i_mutex);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
d = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(d)) {
d = NULL;
goto release_mount;
}
if (d->d_inode) {
d = NULL;
goto release_mount;
}
inode = relayfs_get_inode(parent->d_inode->i_sb, mode, fops, data);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
if (!inode) {
d = NULL;
goto release_mount;
}
d_instantiate(d, inode);
dget(d); /* Extra count - pin the dentry in core */
if (S_ISDIR(mode))
parent->d_inode->i_nlink++;
goto exit;
release_mount:
simple_release_fs(&relayfs_mount, &relayfs_mount_count);
exit:
mutex_unlock(&parent->d_inode->i_mutex);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
dput(parent);
return d;
}
/**
* relayfs_create_file - create a file in the relay filesystem
* @name: the name of the file to create
* @parent: parent directory
* @mode: mode, if not specied the default perms are used
* @fops: file operations to use for the file
[PATCH] relayfs: decouple buffer creation from inode creation The patch series implementa or fixes 3 things that were specifically requested or suggested by relayfs users: - support for non-relay files (patches 1-6) Currently, the relayfs API only supports the creation of directories (relayfs_create_dir()) and relay files (relay_open()). These patches adds support for non-relay files (relayfs_create_file()). This is so relayfs applications can create 'control files' in relayfs itself rather than in /proc or via a netlink channel, as is currently done in the relay-app examples. Basically what this amounts to is exporting relayfs_create_file() with an additional file_ops param that clients can use to supply file operations for their own special-purpose files in relayfs. - make exported relay file ops useful (patches 7-8) The relayfs relay_file_operations have always been exported, the intent being to make it possible to create relay files in other filesystems such as debugfs. The problem, though, is that currently the file operations are too tightly coupled to relayfs to actually be used for this purpose. This patch fixes that by adding a couple of callback functions that allow a client to hook into relay_open()/close() and supply the files that will be used to represent the channel buffers; the default implementation if no callbacks are defined is to create the files in relayfs. - add an option to create global relay buffer (patches 9-10) The file creation callback also supplies an optional param, is_global, that can be used by clients to create a single global relayfs buffer instead of the default per-cpu buffers. This was suggested as being useful for certain debugging applications where it's more convenient to be able to get all the data from a single channel without having to go to the bother of dealing with per-cpu files. - cleanup, some renaming and Documentation updates (patches 11-12) There were several comments that the use of netlink in the example code was non-intuitive and in fact the whole relay-app business was needlessly confusing. Based on that feedback, the example code has been completely converted over to relayfs control files as supported by this patch, and have also been made completely self-contained. The converted examples along with a couple of new examples that demonstrate using exported relay files can be found in relay-apps tarball: http://prdownloads.sourceforge.net/relayfs/relay-apps-0.9.tar.gz?download This patch: Separate buffer create/destroy from inode create/destroy. We want to be able to associate other data and not just relay buffers with inodes. Buffer create/destroy is moved out of inode.c and into relayfs core code. Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 09:02:23 +00:00
* @data: user-associated data for this file
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
*
* Returns file dentry if successful, NULL otherwise.
*
* The file will be created user r on behalf of current user.
*/
struct dentry *relayfs_create_file(const char *name,
struct dentry *parent,
int mode,
struct file_operations *fops,
void *data)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
BUG_ON(!fops);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
if (!mode)
mode = S_IRUSR;
mode = (mode & S_IALLUGO) | S_IFREG;
return relayfs_create_entry(name, parent, mode, fops, data);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
}
/**
* relayfs_create_dir - create a directory in the relay filesystem
* @name: the name of the directory to create
* @parent: parent directory, NULL if parent should be fs root
*
* Returns directory dentry if successful, NULL otherwise.
*
* The directory will be created world rwx on behalf of current user.
*/
struct dentry *relayfs_create_dir(const char *name, struct dentry *parent)
{
int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
return relayfs_create_entry(name, parent, mode, NULL, NULL);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
}
/**
* relayfs_remove - remove a file or directory in the relay filesystem
* @dentry: file or directory dentry
*
* Returns 0 if successful, negative otherwise.
*/
int relayfs_remove(struct dentry *dentry)
{
struct dentry *parent;
int error = 0;
if (!dentry)
return -EINVAL;
parent = dentry->d_parent;
if (!parent)
return -EINVAL;
parent = dget(parent);
mutex_lock(&parent->d_inode->i_mutex);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
if (dentry->d_inode) {
if (S_ISDIR(dentry->d_inode->i_mode))
error = simple_rmdir(parent->d_inode, dentry);
else
error = simple_unlink(parent->d_inode, dentry);
if (!error)
d_delete(dentry);
}
if (!error)
dput(dentry);
mutex_unlock(&parent->d_inode->i_mutex);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
dput(parent);
if (!error)
simple_release_fs(&relayfs_mount, &relayfs_mount_count);
return error;
}
/**
* relayfs_remove_file - remove a file from relay filesystem
* @dentry: directory dentry
*
* Returns 0 if successful, negative otherwise.
*/
int relayfs_remove_file(struct dentry *dentry)
{
return relayfs_remove(dentry);
}
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
/**
* relayfs_remove_dir - remove a directory in the relay filesystem
* @dentry: directory dentry
*
* Returns 0 if successful, negative otherwise.
*/
int relayfs_remove_dir(struct dentry *dentry)
{
return relayfs_remove(dentry);
}
/**
* relay_file_open - open file op for relay files
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
* @inode: the inode
* @filp: the file
*
* Increments the channel buffer refcount.
*/
static int relay_file_open(struct inode *inode, struct file *filp)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
struct rchan_buf *buf = inode->u.generic_ip;
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
kref_get(&buf->kref);
filp->private_data = buf;
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
return 0;
}
/**
* relay_file_mmap - mmap file op for relay files
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
* @filp: the file
* @vma: the vma describing what to map
*
* Calls upon relay_mmap_buf to map the file into user space.
*/
static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
struct rchan_buf *buf = filp->private_data;
return relay_mmap_buf(buf, vma);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
}
/**
* relay_file_poll - poll file op for relay files
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
* @filp: the file
* @wait: poll table
*
* Poll implemention.
*/
static unsigned int relay_file_poll(struct file *filp, poll_table *wait)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
unsigned int mask = 0;
struct rchan_buf *buf = filp->private_data;
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
if (buf->finalized)
return POLLERR;
if (filp->f_mode & FMODE_READ) {
poll_wait(filp, &buf->read_wait, wait);
if (!relay_buf_empty(buf))
mask |= POLLIN | POLLRDNORM;
}
return mask;
}
/**
* relay_file_release - release file op for relay files
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
* @inode: the inode
* @filp: the file
*
* Decrements the channel refcount, as the filesystem is
* no longer using it.
*/
static int relay_file_release(struct inode *inode, struct file *filp)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
struct rchan_buf *buf = filp->private_data;
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
kref_put(&buf->kref, relay_remove_buf);
return 0;
}
/**
* relay_file_read_consume - update the consumed count for the buffer
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
*/
static void relay_file_read_consume(struct rchan_buf *buf,
size_t read_pos,
size_t bytes_consumed)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
size_t subbuf_size = buf->chan->subbuf_size;
size_t n_subbufs = buf->chan->n_subbufs;
size_t read_subbuf;
if (buf->bytes_consumed + bytes_consumed > subbuf_size) {
relay_subbufs_consumed(buf->chan, buf->cpu, 1);
buf->bytes_consumed = 0;
}
buf->bytes_consumed += bytes_consumed;
read_subbuf = read_pos / buf->chan->subbuf_size;
if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) {
if ((read_subbuf == buf->subbufs_produced % n_subbufs) &&
(buf->offset == subbuf_size))
return;
relay_subbufs_consumed(buf->chan, buf->cpu, 1);
buf->bytes_consumed = 0;
}
}
/**
* relay_file_read_avail - boolean, are there unconsumed bytes available?
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
*/
static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
size_t bytes_produced, bytes_consumed, write_offset;
size_t subbuf_size = buf->chan->subbuf_size;
size_t n_subbufs = buf->chan->n_subbufs;
size_t produced = buf->subbufs_produced % n_subbufs;
size_t consumed = buf->subbufs_consumed % n_subbufs;
write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
if (consumed > produced) {
if ((produced > n_subbufs) &&
(produced + n_subbufs - consumed <= n_subbufs))
produced += n_subbufs;
} else if (consumed == produced) {
if (buf->offset > subbuf_size) {
produced += n_subbufs;
if (buf->subbufs_produced == buf->subbufs_consumed)
consumed += n_subbufs;
}
}
if (buf->offset > subbuf_size)
bytes_produced = (produced - 1) * subbuf_size + write_offset;
else
bytes_produced = produced * subbuf_size + write_offset;
bytes_consumed = consumed * subbuf_size + buf->bytes_consumed;
if (bytes_produced == bytes_consumed)
return 0;
relay_file_read_consume(buf, read_pos, 0);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
return 1;
}
/**
* relay_file_read_subbuf_avail - return bytes available in sub-buffer
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
*/
static size_t relay_file_read_subbuf_avail(size_t read_pos,
struct rchan_buf *buf)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
size_t padding, avail = 0;
size_t read_subbuf, read_offset, write_subbuf, write_offset;
size_t subbuf_size = buf->chan->subbuf_size;
write_subbuf = (buf->data - buf->start) / subbuf_size;
write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
read_subbuf = read_pos / subbuf_size;
read_offset = read_pos % subbuf_size;
padding = buf->padding[read_subbuf];
if (read_subbuf == write_subbuf) {
if (read_offset + padding < write_offset)
avail = write_offset - (read_offset + padding);
} else
avail = (subbuf_size - padding) - read_offset;
return avail;
}
/**
* relay_file_read_start_pos - find the first available byte to read
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
*
* If the read_pos is in the middle of padding, return the
* position of the first actually available byte, otherwise
* return the original value.
*/
static size_t relay_file_read_start_pos(size_t read_pos,
struct rchan_buf *buf)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
size_t read_subbuf, padding, padding_start, padding_end;
size_t subbuf_size = buf->chan->subbuf_size;
size_t n_subbufs = buf->chan->n_subbufs;
read_subbuf = read_pos / subbuf_size;
padding = buf->padding[read_subbuf];
padding_start = (read_subbuf + 1) * subbuf_size - padding;
padding_end = (read_subbuf + 1) * subbuf_size;
if (read_pos >= padding_start && read_pos < padding_end) {
read_subbuf = (read_subbuf + 1) % n_subbufs;
read_pos = read_subbuf * subbuf_size;
}
return read_pos;
}
/**
* relay_file_read_end_pos - return the new read position
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
*/
static size_t relay_file_read_end_pos(struct rchan_buf *buf,
size_t read_pos,
size_t count)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
size_t read_subbuf, padding, end_pos;
size_t subbuf_size = buf->chan->subbuf_size;
size_t n_subbufs = buf->chan->n_subbufs;
read_subbuf = read_pos / subbuf_size;
padding = buf->padding[read_subbuf];
if (read_pos % subbuf_size + count + padding == subbuf_size)
end_pos = (read_subbuf + 1) * subbuf_size;
else
end_pos = read_pos + count;
if (end_pos >= subbuf_size * n_subbufs)
end_pos = 0;
return end_pos;
}
/**
* relay_file_read - read file op for relay files
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
* @filp: the file
* @buffer: the userspace buffer
* @count: number of bytes to read
* @ppos: position to read from
*
* Reads count bytes or the number of bytes available in the
* current sub-buffer being read, whichever is smaller.
*/
static ssize_t relay_file_read(struct file *filp,
char __user *buffer,
size_t count,
loff_t *ppos)
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
{
struct rchan_buf *buf = filp->private_data;
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
struct inode *inode = filp->f_dentry->d_inode;
size_t read_start, avail;
ssize_t ret = 0;
void *from;
mutex_lock(&inode->i_mutex);
if(!relay_file_read_avail(buf, *ppos))
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
goto out;
read_start = relay_file_read_start_pos(*ppos, buf);
avail = relay_file_read_subbuf_avail(read_start, buf);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
if (!avail)
goto out;
from = buf->start + read_start;
ret = count = min(count, avail);
if (copy_to_user(buffer, from, count)) {
ret = -EFAULT;
goto out;
}
relay_file_read_consume(buf, read_start, count);
*ppos = relay_file_read_end_pos(buf, read_start, count);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
out:
mutex_unlock(&inode->i_mutex);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
return ret;
}
struct file_operations relay_file_operations = {
.open = relay_file_open,
.poll = relay_file_poll,
.mmap = relay_file_mmap,
.read = relay_file_read,
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
.llseek = no_llseek,
.release = relay_file_release,
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
};
static struct super_operations relayfs_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
};
static int relayfs_fill_super(struct super_block * sb, void * data, int silent)
{
struct inode *inode;
struct dentry *root;
int mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = RELAYFS_MAGIC;
sb->s_op = &relayfs_ops;
inode = relayfs_get_inode(sb, mode, NULL, NULL);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
if (!inode)
return -ENOMEM;
root = d_alloc_root(inode);
if (!root) {
iput(inode);
return -ENOMEM;
}
sb->s_root = root;
return 0;
}
static struct super_block * relayfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data)
{
return get_sb_single(fs_type, flags, data, relayfs_fill_super);
}
static struct file_system_type relayfs_fs_type = {
.owner = THIS_MODULE,
.name = "relayfs",
.get_sb = relayfs_get_sb,
.kill_sb = kill_litter_super,
};
static int __init init_relayfs_fs(void)
{
return register_filesystem(&relayfs_fs_type);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
}
static void __exit exit_relayfs_fs(void)
{
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
unregister_filesystem(&relayfs_fs_type);
}
module_init(init_relayfs_fs)
module_exit(exit_relayfs_fs)
EXPORT_SYMBOL_GPL(relay_file_operations);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
EXPORT_SYMBOL_GPL(relayfs_create_dir);
EXPORT_SYMBOL_GPL(relayfs_remove_dir);
EXPORT_SYMBOL_GPL(relayfs_create_file);
EXPORT_SYMBOL_GPL(relayfs_remove_file);
[PATCH] relayfs Here's the latest version of relayfs, against linux-2.6.11-mm2. I'm hoping you'll consider putting this version back into your tree - the previous rounds of comment seem to have shaken out all the API issues and the number of comments on the code itself have also steadily dwindled. This patch is essentially the same as the relayfs redux part 5 patch, with some minor changes based on reviewer comments. Thanks again to Pekka Enberg for those. The patch size without documentation is now a little smaller at just over 40k. Here's a detailed list of the changes: - removed the attribute_flags in relay open and changed it to a boolean specifying either overwrite or no-overwrite mode, and removed everything referencing the attribute flags. - added a check for NULL names in relayfs_create_entry() - got rid of the unnecessary multiple labels in relay_create_buf() - some minor simplification of relay_alloc_buf() which got rid of a couple params - updated the Documentation In addition, this version (through code contained in the relay-apps tarball linked to below, not as part of the relayfs patch) tries to make it as easy as possible to create the cooperating kernel/user pieces of a typical and common type of logging application, one where kernel logging is kicked off when a user space data collection app starts and stops when the collection app exits, with the data being automatically logged to disk in between. To create this type of application, you basically just include a header file (relay-app.h, included in the relay-apps tarball) in your kernel module, define a couple of callbacks and call an initialization function, and on the user side call a single function that sets up and continuously monitors the buffers, and writes data to files as it becomes available. Channels are created when the collection app is started and destroyed when it exits, not when the kernel module is inserted, so different channel buffer sizes can be specified for each separate run via command-line options. See the README in the relay-apps tarball for details. Also included in the relay-apps tarball are a couple examples demonstrating how you can use this to create quick and dirty kernel logging/debugging applications. They are: - tprintk, short for 'tee printk', which temporarily puts a kprobe on printk() and writes a duplicate stream of printk output to a relayfs channel. This could be used anywhere there's printk() debugging code in the kernel which you'd like to exercise, but would rather not have your system logs cluttered with debugging junk. You'd probably want to kill klogd while you do this, otherwise there wouldn't be much point (since putting a kprobe on printk() doesn't change the output of printk()). I've used this method to temporarily divert the packet logging output of the iptables LOG target from the system logs to relayfs files instead, for instance. - klog, which just provides a printk-like formatted logging function on top of relayfs. Again, you can use this to keep stuff out of your system logs if used in place of printk. The example applications can be found here: http://prdownloads.sourceforge.net/dprobes/relay-apps.tar.gz?download From: Christoph Hellwig <hch@lst.de> avoid lookup_hash usage in relayfs Signed-off-by: Tom Zanussi <zanussi@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 22:16:30 +00:00
MODULE_AUTHOR("Tom Zanussi <zanussi@us.ibm.com> and Karim Yaghmour <karim@opersys.com>");
MODULE_DESCRIPTION("Relay Filesystem");
MODULE_LICENSE("GPL");