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| author | Zhaolei <zhaolei@cn.fujitsu.com> | 2015-08-06 16:39:36 +0200 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2015-08-09 16:07:14 +0200 |
| commit | 166f66d0bc94a14ec4bc6ee6ab079532df4a8d9e (patch) | |
| tree | 276972a024d58650bcf98113bfd264b9ff1c3fb5 /fs/btrfs/locking.c | |
| parent | btrfs: Remove root argument in extent_data_ref_count() (diff) | |
| download | linux-166f66d0bc94a14ec4bc6ee6ab079532df4a8d9e.tar.xz linux-166f66d0bc94a14ec4bc6ee6ab079532df4a8d9e.zip | |
btrfs: Add WARN_ON() for double lock in btrfs_tree_lock()
When a task trying to double lock a extent buffer, there are no
lockdep warning about it because this lock may be in "blocking_lock"
state, and make us hard to debug.
This patch add a WARN_ON() for above condition, it can not report
all deadlock cases(as lock between tasks), but at least helps us
some.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/locking.c')
| -rw-r--r-- | fs/btrfs/locking.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index f8229ef1b46d..d7e6baf1b205 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -241,6 +241,7 @@ void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb) */ void btrfs_tree_lock(struct extent_buffer *eb) { + WARN_ON(eb->lock_owner == current->pid); again: wait_event(eb->read_lock_wq, atomic_read(&eb->blocking_readers) == 0); wait_event(eb->write_lock_wq, atomic_read(&eb->blocking_writers) == 0); |