From a61e6f29dc7c9d56a776a518eed92bbc61848263 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 22 Jul 2008 11:18:08 -0400 Subject: Btrfs: Use a mutex in the extent buffer for tree block locking This replaces the use of the page cache lock bit for locking, which wasn't suitable for block size < page size and couldn't be used recursively. The mutexes alone don't fix either problem, but they are the first step. Signed-off-by: Chris Mason --- fs/btrfs/locking.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'fs/btrfs/locking.c') diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 058a506a0dd..01a9ac2be3f 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -29,32 +29,31 @@ int btrfs_tree_lock(struct extent_buffer *eb) { int i; - if (!TestSetPageLocked(eb->first_page)) + if (mutex_trylock(&eb->mutex)) return 0; for (i = 0; i < 512; i++) { cpu_relax(); - if (!TestSetPageLocked(eb->first_page)) + if (mutex_trylock(&eb->mutex)) return 0; } cpu_relax(); - lock_page(eb->first_page); + mutex_lock(&eb->mutex); return 0; } int btrfs_try_tree_lock(struct extent_buffer *eb) { - return TestSetPageLocked(eb->first_page); + return mutex_trylock(&eb->mutex); } int btrfs_tree_unlock(struct extent_buffer *eb) { - WARN_ON(!PageLocked(eb->first_page)); - unlock_page(eb->first_page); + mutex_unlock(&eb->mutex); return 0; } int btrfs_tree_locked(struct extent_buffer *eb) { - return PageLocked(eb->first_page); + return mutex_is_locked(&eb->mutex); } -- cgit v1.2.3-18-g5258