kill-the-bkl/reiserfs: fix recursive reiserfs lock in reiserfs_mkdir() (b10ab4c3) · Commits · 戴 / test

reiserfs_mkdir() acquires the reiserfs lock, assuming it has been called from the dir inodes callbacks, without the lock held. But it can also be called from other internal sites such as reiserfs_xattr_init() which already holds the lock. This recursive locking leads to further wrong assumptions. For example, later calls to reiserfs_mutex_lock_safe() won't actually unlock the reiserfs lock the time we acquire a given mutex, creating unexpected lock inversions. Signed-off-by:

Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>

fs/reiserfs/namei.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -732,6 +732,7 @@ static int reiserfs_mkdir(struct inode dir, struct dentry dentry, int mode)
		struct inode *inode;
		struct reiserfs_transaction_handle th;
		struct reiserfs_security_handle security;
		int lock_depth;
		/* We need blocks for transaction + (user+group)(quotas for new inode + update of quota for directory owner) /
		int jbegin_count =
		JOURNAL_PER_BALANCE_CNT * 3 +
		@@ -755,7 +756,7 @@ static int reiserfs_mkdir(struct inode dir, struct dentry dentry, int mode)
		return retval;
		}
		jbegin_count += retval;
		reiserfs_write_lock(dir->i_sb);
		lock_depth = reiserfs_write_lock_once(dir->i_sb);

		retval = journal_begin(&th, dir->i_sb, jbegin_count);
		if (retval) {
		@@ -806,7 +807,7 @@ static int reiserfs_mkdir(struct inode dir, struct dentry dentry, int mode)
		unlock_new_inode(inode);
		retval = journal_end(&th, dir->i_sb, jbegin_count);
		out_failed:
		reiserfs_write_unlock(dir->i_sb);
		reiserfs_write_unlock_once(dir->i_sb, lock_depth);
		return retval;
		}

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