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authorLiu Bo <bo.li.liu@oracle.com>2016-11-30 16:20:25 -0800
committerDavid Sterba <dsterba@suse.com>2017-01-03 15:19:28 +0100
commit781feef7e6befafd4d9787d1f7ada1f9ccd504e4 (patch)
treee8f0da62b7c2971b2f73649cf665301aef2272b9 /fs/btrfs
parente321f8a801d7b4c40da8005257b05b9c2b51b072 (diff)
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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>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/tree-log.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f10bf52..eeffff8 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)
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