linux/drivers/mtd/devices/block2mtd.c

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/*
* block2mtd.c - create an mtd from a block device
*
* Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
* Copyright (C) 2004-2006 Joern Engel <joern@wh.fh-wedel.de>
*
* Licence: GPL
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/pagemap.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/buffer_head.h>
#include <linux/mutex.h>
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
#include <linux/mount.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
/* Info for the block device */
struct block2mtd_dev {
struct list_head list;
struct block_device *blkdev;
struct mtd_info mtd;
struct mutex write_mutex;
};
/* Static info about the MTD, used in cleanup_module */
static LIST_HEAD(blkmtd_device_list);
static struct page *page_read(struct address_space *mapping, int index)
{
return read_mapping_page(mapping, index, NULL);
}
/* erase a specified part of the device */
static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
{
struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
struct page *page;
int index = to >> PAGE_SHIFT; // page index
int pages = len >> PAGE_SHIFT;
u_long *p;
u_long *max;
while (pages) {
page = page_read(mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
return PTR_ERR(page);
max = page_address(page) + PAGE_SIZE;
for (p=page_address(page); p<max; p++)
if (*p != -1UL) {
lock_page(page);
memset(page_address(page), 0xff, PAGE_SIZE);
set_page_dirty(page);
unlock_page(page);
break;
}
page_cache_release(page);
pages--;
index++;
}
return 0;
}
static int block2mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
struct block2mtd_dev *dev = mtd->priv;
size_t from = instr->addr;
size_t len = instr->len;
int err;
instr->state = MTD_ERASING;
mutex_lock(&dev->write_mutex);
err = _block2mtd_erase(dev, from, len);
mutex_unlock(&dev->write_mutex);
if (err) {
ERROR("erase failed err = %d", err);
instr->state = MTD_ERASE_FAILED;
} else
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return err;
}
static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct block2mtd_dev *dev = mtd->priv;
struct page *page;
int index = from >> PAGE_SHIFT;
int offset = from & (PAGE_SIZE-1);
int cpylen;
if (from > mtd->size)
return -EINVAL;
if (from + len > mtd->size)
len = mtd->size - from;
if (retlen)
*retlen = 0;
while (len) {
if ((offset + len) > PAGE_SIZE)
cpylen = PAGE_SIZE - offset; // multiple pages
else
cpylen = len; // this page
len = len - cpylen;
page = page_read(dev->blkdev->bd_inode->i_mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
return PTR_ERR(page);
memcpy(buf, page_address(page) + offset, cpylen);
page_cache_release(page);
if (retlen)
*retlen += cpylen;
buf += cpylen;
offset = 0;
index++;
}
return 0;
}
/* write data to the underlying device */
static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
loff_t to, size_t len, size_t *retlen)
{
struct page *page;
struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
int index = to >> PAGE_SHIFT; // page index
int offset = to & ~PAGE_MASK; // page offset
int cpylen;
if (retlen)
*retlen = 0;
while (len) {
if ((offset+len) > PAGE_SIZE)
cpylen = PAGE_SIZE - offset; // multiple pages
else
cpylen = len; // this page
len = len - cpylen;
page = page_read(mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
return PTR_ERR(page);
if (memcmp(page_address(page)+offset, buf, cpylen)) {
lock_page(page);
memcpy(page_address(page) + offset, buf, cpylen);
set_page_dirty(page);
unlock_page(page);
}
page_cache_release(page);
if (retlen)
*retlen += cpylen;
buf += cpylen;
offset = 0;
index++;
}
return 0;
}
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct block2mtd_dev *dev = mtd->priv;
int err;
if (!len)
return 0;
if (to >= mtd->size)
return -ENOSPC;
if (to + len > mtd->size)
len = mtd->size - to;
mutex_lock(&dev->write_mutex);
err = _block2mtd_write(dev, buf, to, len, retlen);
mutex_unlock(&dev->write_mutex);
if (err > 0)
err = 0;
return err;
}
/* sync the device - wait until the write queue is empty */
static void block2mtd_sync(struct mtd_info *mtd)
{
struct block2mtd_dev *dev = mtd->priv;
sync_blockdev(dev->blkdev);
return;
}
static void block2mtd_free_device(struct block2mtd_dev *dev)
{
if (!dev)
return;
kfree(dev->mtd.name);
if (dev->blkdev) {
invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
0, -1);
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
}
kfree(dev);
}
/* FIXME: ensure that mtd->size % erase_size == 0 */
static struct block2mtd_dev *add_device(char *devname, int erase_size)
{
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
struct block_device *bdev;
struct block2mtd_dev *dev;
char *name;
if (!devname)
return NULL;
dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
if (!dev)
return NULL;
/* Get a handle on the device */
bdev = blkdev_get_by_path(devname, mode, dev);
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
#ifndef MODULE
if (IS_ERR(bdev)) {
/* We might not have rootfs mounted at this point. Try
to resolve the device name by other means. */
dev_t devt = name_to_dev_t(devname);
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
if (devt)
bdev = blkdev_get_by_dev(devt, mode, dev);
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
}
#endif
if (IS_ERR(bdev)) {
ERROR("error: cannot open device %s", devname);
goto devinit_err;
}
dev->blkdev = bdev;
if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
ERROR("attempting to use an MTD device as a block device");
goto devinit_err;
}
mutex_init(&dev->write_mutex);
/* Setup the MTD structure */
/* make the name contain the block device in */
name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname);
if (!name)
goto devinit_err;
dev->mtd.name = name;
dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
dev->mtd.erasesize = erase_size;
dev->mtd.writesize = 1;
dev->mtd.type = MTD_RAM;
dev->mtd.flags = MTD_CAP_RAM;
dev->mtd.erase = block2mtd_erase;
dev->mtd.write = block2mtd_write;
dev->mtd.writev = default_mtd_writev;
dev->mtd.sync = block2mtd_sync;
dev->mtd.read = block2mtd_read;
dev->mtd.priv = dev;
dev->mtd.owner = THIS_MODULE;
if (mtd_device_register(&dev->mtd, NULL, 0)) {
/* Device didn't get added, so free the entry */
goto devinit_err;
}
list_add(&dev->list, &blkmtd_device_list);
INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
dev->mtd.name + strlen("block2mtd: "),
dev->mtd.erasesize >> 10, dev->mtd.erasesize);
return dev;
devinit_err:
block2mtd_free_device(dev);
return NULL;
}
/* This function works similar to reguler strtoul. In addition, it
* allows some suffixes for a more human-readable number format:
* ki, Ki, kiB, KiB - multiply result with 1024
* Mi, MiB - multiply result with 1024^2
* Gi, GiB - multiply result with 1024^3
*/
static int ustrtoul(const char *cp, char **endp, unsigned int base)
{
unsigned long result = simple_strtoul(cp, endp, base);
switch (**endp) {
case 'G' :
result *= 1024;
case 'M':
result *= 1024;
case 'K':
case 'k':
result *= 1024;
/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
if ((*endp)[1] == 'i') {
if ((*endp)[2] == 'B')
(*endp) += 3;
else
(*endp) += 2;
}
}
return result;
}
static int parse_num(size_t *num, const char *token)
{
char *endp;
size_t n;
n = (size_t) ustrtoul(token, &endp, 0);
if (*endp)
return -EINVAL;
*num = n;
return 0;
}
static inline void kill_final_newline(char *str)
{
char *newline = strrchr(str, '\n');
if (newline && !newline[1])
*newline = 0;
}
#define parse_err(fmt, args...) do { \
ERROR(fmt, ## args); \
return 0; \
} while (0)
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
#ifndef MODULE
static int block2mtd_init_called = 0;
static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
#endif
static int block2mtd_setup2(const char *val)
{
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
char buf[80 + 12]; /* 80 for device, 12 for erase size */
char *str = buf;
char *token[2];
char *name;
size_t erase_size = PAGE_SIZE;
int i, ret;
if (strnlen(val, sizeof(buf)) >= sizeof(buf))
parse_err("parameter too long");
strcpy(str, val);
kill_final_newline(str);
for (i = 0; i < 2; i++)
token[i] = strsep(&str, ",");
if (str)
parse_err("too many arguments");
if (!token[0])
parse_err("no argument");
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
name = token[0];
if (strlen(name) + 1 > 80)
parse_err("device name too long");
if (token[1]) {
ret = parse_num(&erase_size, token[1]);
if (ret) {
parse_err("illegal erase size");
}
}
add_device(name, erase_size);
return 0;
}
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
static int block2mtd_setup(const char *val, struct kernel_param *kp)
{
#ifdef MODULE
return block2mtd_setup2(val);
#else
/* If more parameters are later passed in via
/sys/module/block2mtd/parameters/block2mtd
and block2mtd_init() has already been called,
we can parse the argument now. */
if (block2mtd_init_called)
return block2mtd_setup2(val);
/* During early boot stage, we only save the parameters
here. We must parse them later: if the param passed
from kernel boot command line, block2mtd_setup() is
called so early that it is not possible to resolve
the device (even kmalloc() fails). Deter that work to
block2mtd_setup2(). */
strlcpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));
return 0;
#endif
}
module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
static int __init block2mtd_init(void)
{
block2mtd.c: Make kernel boot command line arguments work (try 4) Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-13 21:31:16 +00:00
int ret = 0;
#ifndef MODULE
if (strlen(block2mtd_paramline))
ret = block2mtd_setup2(block2mtd_paramline);
block2mtd_init_called = 1;
#endif
return ret;
}
static void __devexit block2mtd_exit(void)
{
struct list_head *pos, *next;
/* Remove the MTD devices */
list_for_each_safe(pos, next, &blkmtd_device_list) {
struct block2mtd_dev *dev = list_entry(pos, typeof(*dev), list);
block2mtd_sync(&dev->mtd);
mtd_device_unregister(&dev->mtd);
INFO("mtd%d: [%s] removed", dev->mtd.index,
dev->mtd.name + strlen("block2mtd: "));
list_del(&dev->list);
block2mtd_free_device(dev);
}
}
module_init(block2mtd_init);
module_exit(block2mtd_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joern Engel <joern@lazybastard.org>");
MODULE_DESCRIPTION("Emulate an MTD using a block device");