linux/fs/freevxfs/vxfs_super.c

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/*
* Copyright (c) 2000-2001 Christoph Hellwig.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL").
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Veritas filesystem driver - superblock related routines.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/vfs.h>
#include <linux/mount.h>
#include "vxfs.h"
#include "vxfs_extern.h"
#include "vxfs_dir.h"
#include "vxfs_inode.h"
MODULE_AUTHOR("Christoph Hellwig");
MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("vxfs"); /* makes mount -t vxfs autoload the module */
static void vxfs_put_super(struct super_block *);
static int vxfs_statfs(struct dentry *, struct kstatfs *);
static int vxfs_remount(struct super_block *, int *, char *);
static const struct super_operations vxfs_super_ops = {
.read_inode = vxfs_read_inode,
.clear_inode = vxfs_clear_inode,
.put_super = vxfs_put_super,
.statfs = vxfs_statfs,
.remount_fs = vxfs_remount,
};
/**
* vxfs_put_super - free superblock resources
* @sbp: VFS superblock.
*
* Description:
* vxfs_put_super frees all resources allocated for @sbp
* after the last instance of the filesystem is unmounted.
*/
static void
vxfs_put_super(struct super_block *sbp)
{
struct vxfs_sb_info *infp = VXFS_SBI(sbp);
vxfs_put_fake_inode(infp->vsi_fship);
vxfs_put_fake_inode(infp->vsi_ilist);
vxfs_put_fake_inode(infp->vsi_stilist);
brelse(infp->vsi_bp);
kfree(infp);
}
/**
* vxfs_statfs - get filesystem information
* @dentry: VFS dentry to locate superblock
* @bufp: output buffer
*
* Description:
* vxfs_statfs fills the statfs buffer @bufp with information
* about the filesystem described by @dentry.
*
* Returns:
* Zero.
*
* Locking:
* No locks held.
*
* Notes:
* This is everything but complete...
*/
static int
vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
{
struct vxfs_sb_info *infp = VXFS_SBI(dentry->d_sb);
bufp->f_type = VXFS_SUPER_MAGIC;
bufp->f_bsize = dentry->d_sb->s_blocksize;
bufp->f_blocks = infp->vsi_raw->vs_dsize;
bufp->f_bfree = infp->vsi_raw->vs_free;
bufp->f_bavail = 0;
bufp->f_files = 0;
bufp->f_ffree = infp->vsi_raw->vs_ifree;
bufp->f_namelen = VXFS_NAMELEN;
return 0;
}
static int vxfs_remount(struct super_block *sb, int *flags, char *data)
{
*flags |= MS_RDONLY;
return 0;
}
/**
* vxfs_read_super - read superblock into memory and initalize filesystem
* @sbp: VFS superblock (to fill)
* @dp: fs private mount data
* @silent: do not complain loudly when sth is wrong
*
* Description:
* We are called on the first mount of a filesystem to read the
* superblock into memory and do some basic setup.
*
* Returns:
* The superblock on success, else %NULL.
*
* Locking:
* We are under the bkl and @sbp->s_lock.
*/
static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
{
struct vxfs_sb_info *infp;
struct vxfs_sb *rsbp;
struct buffer_head *bp = NULL;
u_long bsize;
struct inode *root;
sbp->s_flags |= MS_RDONLY;
infp = kzalloc(sizeof(*infp), GFP_KERNEL);
if (!infp) {
printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
return -ENOMEM;
}
bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
if (!bsize) {
printk(KERN_WARNING "vxfs: unable to set blocksize\n");
goto out;
}
bp = sb_bread(sbp, 1);
if (!bp || !buffer_mapped(bp)) {
if (!silent) {
printk(KERN_WARNING
"vxfs: unable to read disk superblock\n");
}
goto out;
}
rsbp = (struct vxfs_sb *)bp->b_data;
if (rsbp->vs_magic != VXFS_SUPER_MAGIC) {
if (!silent)
printk(KERN_NOTICE "vxfs: WRONG superblock magic\n");
goto out;
}
if ((rsbp->vs_version < 2 || rsbp->vs_version > 4) && !silent) {
printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n",
rsbp->vs_version);
goto out;
}
#ifdef DIAGNOSTIC
printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", rsbp->vs_version);
printk(KERN_DEBUG "vxfs: blocksize: %d\n", rsbp->vs_bsize);
#endif
sbp->s_magic = rsbp->vs_magic;
sbp->s_fs_info = infp;
infp->vsi_raw = rsbp;
infp->vsi_bp = bp;
infp->vsi_oltext = rsbp->vs_oltext[0];
infp->vsi_oltsize = rsbp->vs_oltsize;
if (!sb_set_blocksize(sbp, rsbp->vs_bsize)) {
printk(KERN_WARNING "vxfs: unable to set final block size\n");
goto out;
}
if (vxfs_read_olt(sbp, bsize)) {
printk(KERN_WARNING "vxfs: unable to read olt\n");
goto out;
}
if (vxfs_read_fshead(sbp)) {
printk(KERN_WARNING "vxfs: unable to read fshead\n");
goto out;
}
sbp->s_op = &vxfs_super_ops;
root = iget(sbp, VXFS_ROOT_INO);
sbp->s_root = d_alloc_root(root);
if (!sbp->s_root) {
iput(root);
printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
goto out_free_ilist;
}
return 0;
out_free_ilist:
vxfs_put_fake_inode(infp->vsi_fship);
vxfs_put_fake_inode(infp->vsi_ilist);
vxfs_put_fake_inode(infp->vsi_stilist);
out:
brelse(bp);
kfree(infp);
return -EINVAL;
}
/*
* The usual module blurb.
*/
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
static int vxfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
return get_sb_bdev(fs_type, flags, dev_name, data, vxfs_fill_super,
mnt);
}
static struct file_system_type vxfs_fs_type = {
.owner = THIS_MODULE,
.name = "vxfs",
.get_sb = vxfs_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init
vxfs_init(void)
{
int rv;
vxfs_inode_cachep = kmem_cache_create("vxfs_inode",
sizeof(struct vxfs_inode_info), 0,
SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
if (!vxfs_inode_cachep)
return -ENOMEM;
rv = register_filesystem(&vxfs_fs_type);
if (rv < 0)
kmem_cache_destroy(vxfs_inode_cachep);
return rv;
}
static void __exit
vxfs_cleanup(void)
{
unregister_filesystem(&vxfs_fs_type);
kmem_cache_destroy(vxfs_inode_cachep);
}
module_init(vxfs_init);
module_exit(vxfs_cleanup);