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authorPatrick McHardy <kaber@trash.net>2013-03-31 18:10:34 +0200
committerPatrick McHardy <kaber@trash.net>2013-03-31 18:10:34 +0200
commit70711d223510ba1773cfe1d7770a56141c815ff8 (patch)
tree4a71f38a3a554ddecaa31b7d8c6bc49b7d1705b4 /fs/btrfs/locking.c
parentd53b4ed072d9779cdf53582c46436dec06d0961f (diff)
parent19f949f52599ba7c3f67a5897ac6be14bfcb1200 (diff)
Merge tag 'v3.8' of /home/kaber/src/repos/linux
Linux 3.8 Signed-off-by: Patrick McHardy <kaber@trash.net> Conflicts: include/linux/Kbuild include/linux/netlink.h
Diffstat (limited to 'fs/btrfs/locking.c')
-rw-r--r--fs/btrfs/locking.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 272f911203f..2a1762c6604 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -67,7 +67,7 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
{
if (eb->lock_nested) {
read_lock(&eb->lock);
- if (&eb->lock_nested && current->pid == eb->lock_owner) {
+ if (eb->lock_nested && current->pid == eb->lock_owner) {
read_unlock(&eb->lock);
return;
}
@@ -78,13 +78,15 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
write_lock(&eb->lock);
WARN_ON(atomic_read(&eb->spinning_writers));
atomic_inc(&eb->spinning_writers);
- if (atomic_dec_and_test(&eb->blocking_writers))
+ if (atomic_dec_and_test(&eb->blocking_writers) &&
+ waitqueue_active(&eb->write_lock_wq))
wake_up(&eb->write_lock_wq);
} else if (rw == BTRFS_READ_LOCK_BLOCKING) {
BUG_ON(atomic_read(&eb->blocking_readers) == 0);
read_lock(&eb->lock);
atomic_inc(&eb->spinning_readers);
- if (atomic_dec_and_test(&eb->blocking_readers))
+ if (atomic_dec_and_test(&eb->blocking_readers) &&
+ waitqueue_active(&eb->read_lock_wq))
wake_up(&eb->read_lock_wq);
}
return;
@@ -199,7 +201,8 @@ void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb)
}
btrfs_assert_tree_read_locked(eb);
WARN_ON(atomic_read(&eb->blocking_readers) == 0);
- if (atomic_dec_and_test(&eb->blocking_readers))
+ if (atomic_dec_and_test(&eb->blocking_readers) &&
+ waitqueue_active(&eb->read_lock_wq))
wake_up(&eb->read_lock_wq);
atomic_dec(&eb->read_locks);
}
@@ -247,8 +250,9 @@ void btrfs_tree_unlock(struct extent_buffer *eb)
if (blockers) {
WARN_ON(atomic_read(&eb->spinning_writers));
atomic_dec(&eb->blocking_writers);
- smp_wmb();
- wake_up(&eb->write_lock_wq);
+ smp_mb();
+ if (waitqueue_active(&eb->write_lock_wq))
+ wake_up(&eb->write_lock_wq);
} else {
WARN_ON(atomic_read(&eb->spinning_writers) != 1);
atomic_dec(&eb->spinning_writers);