diff options
| author | Liu Bo <bo.li.liu@oracle.com> | 2016-11-30 16:20:25 -0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2017-01-03 15:19:28 +0100 |
| commit | 781feef7e6befafd4d9787d1f7ada1f9ccd504e4 (patch) | |
| tree | e8f0da62b7c2971b2f73649cf665301aef2272b9 | |
| parent | e321f8a801d7b4c40da8005257b05b9c2b51b072 (diff) | |
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: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/tree-log.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index f10bf5213ed8..eeffff84f280 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -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; } - mutex_lock(&BTRFS_I(inode)->log_mutex); + 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 @@ again: * 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) |