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Commit 4843456c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  quota: Fix deadlock during path resolution
parents 2b1caf6e f00c9e44

fs/ext3/super.c

+7 −18
Original line number Diff line number Diff line
@@ -754,7 +754,7 @@ static int ext3_release_dquot(struct dquot *dquot); 
static int ext3_mark_dquot_dirty(struct dquot *dquot);

static int ext3_write_info(struct super_block *sb, int type);

static int ext3_quota_on(struct super_block *sb, int type, int format_id,

				char *path);

			 struct path *path);

static int ext3_quota_on_mount(struct super_block *sb, int type);

static ssize_t ext3_quota_read(struct super_block *sb, int type, char *data,

			       size_t len, loff_t off);
@@ -2877,27 +2877,20 @@ static int ext3_quota_on_mount(struct super_block *sb, int type) 
 * Standard function to be called on quota_on

 */

static int ext3_quota_on(struct super_block *sb, int type, int format_id,

			 char *name)

			 struct path *path)

{

	int err;

	struct path path;



	if (!test_opt(sb, QUOTA))

		return -EINVAL;



	err = kern_path(name, LOOKUP_FOLLOW, &path);

	if (err)

		return err;



	/* Quotafile not on the same filesystem? */

	if (path.mnt->mnt_sb != sb) {

		path_put(&path);

	if (path->mnt->mnt_sb != sb)

		return -EXDEV;

	}

	/* Journaling quota? */

	if (EXT3_SB(sb)->s_qf_names[type]) {

		/* Quotafile not of fs root? */

		if (path.dentry->d_parent != sb->s_root)

		if (path->dentry->d_parent != sb->s_root)

			ext3_msg(sb, KERN_WARNING,

				"warning: Quota file not on filesystem root. "

				"Journaled quota will not work.");
@@ -2907,7 +2900,7 @@ static int ext3_quota_on(struct super_block *sb, int type, int format_id, 
	 * When we journal data on quota file, we have to flush journal to see

	 * all updates to the file when we bypass pagecache...

	 */

	if (ext3_should_journal_data(path.dentry->d_inode)) {

	if (ext3_should_journal_data(path->dentry->d_inode)) {

		/*

		 * We don't need to lock updates but journal_flush() could

		 * otherwise be livelocked...
@@ -2915,15 +2908,11 @@ static int ext3_quota_on(struct super_block *sb, int type, int format_id, 
		journal_lock_updates(EXT3_SB(sb)->s_journal);

		err = journal_flush(EXT3_SB(sb)->s_journal);

		journal_unlock_updates(EXT3_SB(sb)->s_journal);

		if (err) {

			path_put(&path);

		if (err)

			return err;

	}

	}



	err = dquot_quota_on_path(sb, type, format_id, &path);

	path_put(&path);

	return err;

	return dquot_quota_on(sb, type, format_id, path);

}



/* Read data from quotafile - avoid pagecache and such because we cannot afford

fs/ext4/super.c

+7 −18
Original line number Diff line number Diff line
@@ -1161,7 +1161,7 @@ static int ext4_release_dquot(struct dquot *dquot); 
static int ext4_mark_dquot_dirty(struct dquot *dquot);

static int ext4_write_info(struct super_block *sb, int type);

static int ext4_quota_on(struct super_block *sb, int type, int format_id,

				char *path);

			 struct path *path);

static int ext4_quota_off(struct super_block *sb, int type);

static int ext4_quota_on_mount(struct super_block *sb, int type);

static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
@@ -4558,27 +4558,20 @@ static int ext4_quota_on_mount(struct super_block *sb, int type) 
 * Standard function to be called on quota_on

 */

static int ext4_quota_on(struct super_block *sb, int type, int format_id,

			 char *name)

			 struct path *path)

{

	int err;

	struct path path;



	if (!test_opt(sb, QUOTA))

		return -EINVAL;



	err = kern_path(name, LOOKUP_FOLLOW, &path);

	if (err)

		return err;



	/* Quotafile not on the same filesystem? */

	if (path.mnt->mnt_sb != sb) {

		path_put(&path);

	if (path->mnt->mnt_sb != sb)

		return -EXDEV;

	}

	/* Journaling quota? */

	if (EXT4_SB(sb)->s_qf_names[type]) {

		/* Quotafile not in fs root? */

		if (path.dentry->d_parent != sb->s_root)

		if (path->dentry->d_parent != sb->s_root)

			ext4_msg(sb, KERN_WARNING,

				"Quota file not on filesystem root. "

				"Journaled quota will not work");
@@ -4589,7 +4582,7 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id, 
	 * all updates to the file when we bypass pagecache...

	 */

	if (EXT4_SB(sb)->s_journal &&

	    ext4_should_journal_data(path.dentry->d_inode)) {

	    ext4_should_journal_data(path->dentry->d_inode)) {

		/*

		 * We don't need to lock updates but journal_flush() could

		 * otherwise be livelocked...
@@ -4597,15 +4590,11 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id, 
		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);

		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);

		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);

		if (err) {

			path_put(&path);

		if (err)

			return err;

	}

	}



	err = dquot_quota_on_path(sb, type, format_id, &path);

	path_put(&path);

	return err;

	return dquot_quota_on(sb, type, format_id, path);

}



static int ext4_quota_off(struct super_block *sb, int type)

fs/ocfs2/super.c

+2 −3
Original line number Diff line number Diff line
@@ -993,8 +993,7 @@ static void ocfs2_disable_quotas(struct ocfs2_super *osb) 
}



/* Handle quota on quotactl */

static int ocfs2_quota_on(struct super_block *sb, int type, int format_id,

			  char *path)

static int ocfs2_quota_on(struct super_block *sb, int type, int format_id)

{

	unsigned int feature[MAXQUOTAS] = { OCFS2_FEATURE_RO_COMPAT_USRQUOTA,

					     OCFS2_FEATURE_RO_COMPAT_GRPQUOTA};
@@ -1013,7 +1012,7 @@ static int ocfs2_quota_off(struct super_block *sb, int type) 
}



static const struct quotactl_ops ocfs2_quotactl_ops = {

	.quota_on	= ocfs2_quota_on,

	.quota_on_meta	= ocfs2_quota_on,

	.quota_off	= ocfs2_quota_off,

	.quota_sync	= dquot_quota_sync,

	.get_info	= dquot_get_dqinfo,

fs/quota/dquot.c

+2 −16
Original line number Diff line number Diff line
@@ -2189,7 +2189,7 @@ int dquot_resume(struct super_block *sb, int type) 
}

EXPORT_SYMBOL(dquot_resume);



int dquot_quota_on_path(struct super_block *sb, int type, int format_id,

int dquot_quota_on(struct super_block *sb, int type, int format_id,

		   struct path *path)

{

	int error = security_quota_on(path->dentry);
@@ -2204,20 +2204,6 @@ int dquot_quota_on_path(struct super_block *sb, int type, int format_id, 
					     DQUOT_LIMITS_ENABLED);

	return error;

}

EXPORT_SYMBOL(dquot_quota_on_path);



int dquot_quota_on(struct super_block *sb, int type, int format_id, char *name)

{

	struct path path;

	int error;



	error = kern_path(name, LOOKUP_FOLLOW, &path);

	if (!error) {

		error = dquot_quota_on_path(sb, type, format_id, &path);

		path_put(&path);

	}

	return error;

}

EXPORT_SYMBOL(dquot_quota_on);



/*

fs/quota/quota.c

+27 −14
Original line number Diff line number Diff line
@@ -64,18 +64,15 @@ static int quota_sync_all(int type) 
}



static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,

		         void __user *addr)

		         struct path *path)

{

	char *pathname;

	int ret = -ENOSYS;



	pathname = getname(addr);

	if (IS_ERR(pathname))

		return PTR_ERR(pathname);

	if (sb->s_qcop->quota_on)

		ret = sb->s_qcop->quota_on(sb, type, id, pathname);

	putname(pathname);

	return ret;

	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)

		return -ENOSYS;

	if (sb->s_qcop->quota_on_meta)

		return sb->s_qcop->quota_on_meta(sb, type, id);

	if (IS_ERR(path))

		return PTR_ERR(path);

	return sb->s_qcop->quota_on(sb, type, id, path);

}



static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
@@ -241,7 +238,7 @@ static int quota_getxquota(struct super_block *sb, int type, qid_t id, 


/* Copy parameters and call proper function */

static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,

		       void __user *addr)

		       void __user *addr, struct path *path)

{

	int ret;
@@ -256,7 +253,7 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, 


	switch (cmd) {

	case Q_QUOTAON:

		return quota_quotaon(sb, type, cmd, id, addr);

		return quota_quotaon(sb, type, cmd, id, path);

	case Q_QUOTAOFF:

		if (!sb->s_qcop->quota_off)

			return -ENOSYS;
@@ -335,6 +332,7 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, 
{

	uint cmds, type;

	struct super_block *sb = NULL;

	struct path path, *pathp = NULL;

	int ret;



	cmds = cmd >> SUBCMDSHIFT;
@@ -351,12 +349,27 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, 
		return -ENODEV;

	}



	/*

	 * Path for quotaon has to be resolved before grabbing superblock

	 * because that gets s_umount sem which is also possibly needed by path

	 * resolution (think about autofs) and thus deadlocks could arise.

	 */

	if (cmds == Q_QUOTAON) {

		ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW, &path);

		if (ret)

			pathp = ERR_PTR(ret);

		else

			pathp = &path;

	}



	sb = quotactl_block(special);

	if (IS_ERR(sb))

		return PTR_ERR(sb);



	ret = do_quotactl(sb, type, cmds, id, addr);

	ret = do_quotactl(sb, type, cmds, id, addr, pathp);



	drop_super(sb);

	if (pathp && !IS_ERR(pathp))

		path_put(pathp);

	return ret;

}