Commit 3bb3e1fc authored by Jan Kara's avatar Jan Kara
Browse files

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: default avatarJan Kara <jack@suse.cz>
parent 77b67063

fs/reiserfs/super.c

+20 −7
Original line number Original line Diff line number Diff line
@@ -1335,7 +1335,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg) 
				kfree(qf_names[i]);

				kfree(qf_names[i]);

#endif

#endif

		err = -EINVAL;

		err = -EINVAL;

		goto out_err;

		goto out_unlock;

	}

	}

#ifdef CONFIG_QUOTA

#ifdef CONFIG_QUOTA

	handle_quota_files(s, qf_names, &qfmt);

	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) {

	if (blocks) {

		err = reiserfs_resize(s, blocks);

		err = reiserfs_resize(s, blocks);

		if (err != 0)

		if (err != 0)

			goto out_err;

			goto out_unlock;

	}

	}





	if (*mount_flags & MS_RDONLY) {

	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 */

			/* it is read-only already */

			goto out_ok;

			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);

		err = dquot_suspend(s, -1);

		if (err < 0)

		if (err < 0)

			goto out_err;

			goto out_err;

		reiserfs_write_lock(s);





		/* try to remount file system with read-only permissions */

		/* try to remount file system with read-only permissions */

		if (sb_umount_state(rs) == REISERFS_VALID_FS

		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);

		err = journal_begin(&th, s, 10);

		if (err)

		if (err)

			goto out_err;

			goto out_unlock;





		/* Mounting a rw partition read-only. */

		/* Mounting a rw partition read-only. */

		reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);

		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)) {

		if (reiserfs_is_journal_aborted(journal)) {

			err = journal->j_errno;

			err = journal->j_errno;

			goto out_err;

			goto out_unlock;

		}

		}





		handle_data_mode(s, mount_options);

		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 */

		s->s_flags &= ~MS_RDONLY;	/* now it is safe to call journal_begin */

		err = journal_begin(&th, s, 10);

		err = journal_begin(&th, s, 10);

		if (err)

		if (err)

			goto out_err;

			goto out_unlock;





		/* Mount a partition which is read-only, read-write */

		/* Mount a partition which is read-only, read-write */

		reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);

		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;

	SB_JOURNAL(s)->j_must_wait = 1;

	err = journal_end(&th, s, 10);

	err = journal_end(&th, s, 10);

	if (err)

	if (err)

		goto out_err;

		goto out_unlock;





	if (!(*mount_flags & MS_RDONLY)) {

	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);

		dquot_resume(s, -1);

		reiserfs_write_lock(s);

		finish_unfinished(s);

		finish_unfinished(s);

		reiserfs_xattr_init(s, *mount_flags);

		reiserfs_xattr_init(s, *mount_flags);

	}

	}
@@ -1455,9 +1467,10 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg) 
	reiserfs_write_unlock(s);

	reiserfs_write_unlock(s);

	return 0;

	return 0;





out_unlock:

	reiserfs_write_unlock(s);

out_err:

out_err:

	kfree(new_opts);

	kfree(new_opts);

	reiserfs_write_unlock(s);

	return err;

	return err;

}

}