Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 781feef7 authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: fix lockdep warning about log_mutex 



While checking INODE_REF/INODE_EXTREF for a corner case, we may acquire a
different inode's log_mutex with holding the current inode's log_mutex, and
lockdep has complained this with a possilble deadlock warning.

Fix this by using mutex_lock_nested() when processing the other inode's
log_mutex.

Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent e321f8a8

fs/btrfs/tree-log.c

+10 −3
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
 */

#define LOG_INODE_ALL 0

#define LOG_INODE_EXISTS 1

#define LOG_OTHER_INODE 2



/*

 * directory trouble cases
@@ -4641,7 +4642,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, 
	if (S_ISDIR(inode->i_mode) ||

	    (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,

		       &BTRFS_I(inode)->runtime_flags) &&

	     inode_only == LOG_INODE_EXISTS))

	     inode_only >= LOG_INODE_EXISTS))

		max_key.type = BTRFS_XATTR_ITEM_KEY;

	else

		max_key.type = (u8)-1;
@@ -4665,7 +4666,13 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, 
		return ret;

	}



	if (inode_only == LOG_OTHER_INODE) {

		inode_only = LOG_INODE_EXISTS;

		mutex_lock_nested(&BTRFS_I(inode)->log_mutex,

				  SINGLE_DEPTH_NESTING);

	} else {

		mutex_lock(&BTRFS_I(inode)->log_mutex);

	}



	/*

	 * a brute force approach to making sure we get the most uptodate
@@ -4817,7 +4824,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, 
				 * unpin it.

				 */

				err = btrfs_log_inode(trans, root, other_inode,

						      LOG_INODE_EXISTS,

						      LOG_OTHER_INODE,

						      0, LLONG_MAX, ctx);

				iput(other_inode);

				if (err)