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[XFS] fix mount option parsing in remount 

Remount currently happily accept any option thrown at it, although the
only filesystem specific option it actually handles is barrier/nobarrier.
And it actually doesn't handle these correctly either because it only uses
the value it parsed when we're doing a ro->rw transition. In addition to
that there's also a bad bug in xfs_parseargs which doesn't touch the
actual option in the mount point except for a single one,
XFS_MOUNT_SMALL_INUMS and thus forced any filesystem that's every
remounted in some way to not support 64bit inodes with no way to recover
unless unmounted.

This patch changes xfs_fs_remount to use it's own linux/parser.h based
options parse instead of xfs_parseargs and reject all options except for
barrier/nobarrier and to the right thing in general. Eventually I'd like
to have a single big option table used for mount aswell but that can wait
for a while.

SGI-PV: 983964

SGI-Modid: xfs-linux-melb:xfs-kern:31382a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
This commit is contained in:
Christoph Hellwig 2008-07-18 17:12:36 +10:00 committed by Niv Sardi
parent deeb5912db
commit 62a877e35d
1 changed files with 54 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
fs/xfs/linux-2.6/xfs_super.c
View File

@ -66,6 +66,7 @@
#include <linux/writeback.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/parser.h>
static struct quotactl_ops xfs_quotactl_operations;
static struct super_operations xfs_super_operations;
@ -147,6 +148,23 @@ xfs_args_allocate(
#define MNTOPT_XDSM "xdsm" /* DMI enabled (DMAPI / XDSM) */
#define MNTOPT_DMI "dmi" /* DMI enabled (DMAPI / XDSM) */
/*
* Table driven mount option parser.
*
* Currently only used for remount, but it will be used for mount
* in the future, too.
*/
enum {
Opt_barrier, Opt_nobarrier, Opt_err
};
static match_table_t tokens = {
{Opt_barrier, "barrier"},
{Opt_nobarrier, "nobarrier"},
{Opt_err, NULL}
};
STATIC unsigned long
suffix_strtoul(char *s, char **endp, unsigned int base)
{
@ -1364,36 +1382,54 @@ xfs_fs_remount(
char *options)
{
struct xfs_mount *mp = XFS_M(sb);
struct xfs_mount_args *args;
int error;
substring_t args[MAX_OPT_ARGS];
char *p;
args = xfs_args_allocate(sb, 0);
if (!args)
return -ENOMEM;
while ((p = strsep(&options, ",")) != NULL) {
int token;
error = xfs_parseargs(mp, options, args, 1);
if (error)
goto out_free_args;
if (!*p)
continue;
if (!(*flags & MS_RDONLY)) { /* rw/ro -> rw */
if (mp->m_flags & XFS_MOUNT_RDONLY)
mp->m_flags &= ~XFS_MOUNT_RDONLY;
if (args->flags & XFSMNT_BARRIER) {
token = match_token(p, tokens, args);
switch (token) {
case Opt_barrier:
mp->m_flags |= XFS_MOUNT_BARRIER;
xfs_mountfs_check_barriers(mp);
} else {
/*
* Test if barriers are actually working if we can,
* else delay this check until the filesystem is
* marked writeable.
*/
if (!(mp->m_flags & XFS_MOUNT_RDONLY))
xfs_mountfs_check_barriers(mp);
break;
case Opt_nobarrier:
mp->m_flags &= ~XFS_MOUNT_BARRIER;
break;
default:
printk(KERN_INFO
"XFS: mount option \"%s\" not supported for remount\n", p);
return -EINVAL;
}
} else if (!(mp->m_flags & XFS_MOUNT_RDONLY)) { /* rw -> ro */
}
/* rw/ro -> rw */
if ((mp->m_flags & XFS_MOUNT_RDONLY) && !(*flags & MS_RDONLY)) {
mp->m_flags &= ~XFS_MOUNT_RDONLY;
if (mp->m_flags & XFS_MOUNT_BARRIER)
xfs_mountfs_check_barriers(mp);
}
/* rw -> ro */
if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & MS_RDONLY)) {
xfs_filestream_flush(mp);
xfs_sync(mp, SYNC_DATA_QUIESCE);
xfs_attr_quiesce(mp);
mp->m_flags |= XFS_MOUNT_RDONLY;
}
out_free_args:
kfree(args);
return -error;
return 0;
}
/*