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reiserfs: Fix lock ordering during remount 

When remounting reiserfs dquot_suspend() or dquot_resume() can be called.
These functions take dqonoff_mutex which ranks above write lock so we have
to drop it before calling into quota code.

CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2012-11-13 14:55:52 +01:00
parent 77b67063bb
commit 3bb3e1fc47
1 changed files with 20 additions and 7 deletions
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27
fs/reiserfs/super.c
View File

@ -1335,7 +1335,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
kfree(qf_names[i]);
#endif
err = -EINVAL;
goto out_err;
goto out_unlock;
}
#ifdef CONFIG_QUOTA
handle_quota_files(s, qf_names, &qfmt);
@ -1379,7 +1379,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
if (blocks) {
err = reiserfs_resize(s, blocks);
if (err != 0)
goto out_err;
goto out_unlock;
}
if (*mount_flags & MS_RDONLY) {
@ -1389,9 +1389,15 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
/* it is read-only already */
goto out_ok;
/*
* Drop write lock. Quota will retake it when needed and lock
* ordering requires calling dquot_suspend() without it.
*/
reiserfs_write_unlock(s);
err = dquot_suspend(s, -1);
if (err < 0)
goto out_err;
reiserfs_write_lock(s);
/* try to remount file system with read-only permissions */
if (sb_umount_state(rs) == REISERFS_VALID_FS
@ -1401,7 +1407,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
err = journal_begin(&th, s, 10);
if (err)
goto out_err;
goto out_unlock;
/* Mounting a rw partition read-only. */
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
@ -1416,7 +1422,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
if (reiserfs_is_journal_aborted(journal)) {
err = journal->j_errno;
goto out_err;
goto out_unlock;
}
handle_data_mode(s, mount_options);
@ -1425,7 +1431,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
s->s_flags &= ~MS_RDONLY; /* now it is safe to call journal_begin */
err = journal_begin(&th, s, 10);
if (err)
goto out_err;
goto out_unlock;
/* Mount a partition which is read-only, read-write */
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
@ -1442,10 +1448,16 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
SB_JOURNAL(s)->j_must_wait = 1;
err = journal_end(&th, s, 10);
if (err)
goto out_err;
goto out_unlock;
if (!(*mount_flags & MS_RDONLY)) {
/*
* Drop write lock. Quota will retake it when needed and lock
* ordering requires calling dquot_resume() without it.
*/
reiserfs_write_unlock(s);
dquot_resume(s, -1);
reiserfs_write_lock(s);
finish_unfinished(s);
reiserfs_xattr_init(s, *mount_flags);
}
@ -1455,9 +1467,10 @@ out_ok:
reiserfs_write_unlock(s);
return 0;
out_unlock:
reiserfs_write_unlock(s);
out_err:
kfree(new_opts);
reiserfs_write_unlock(s);
return err;
}