reiserfs: locking, handle nested locks properly
The reiserfs write lock replaced the BKL and uses similar semantics.
Frederic's locking code makes a distinction between when the lock is nested
and when it's being acquired/released, but I don't think that's the right
distinction to make.
The right distinction is between the lock being released at end-of-use and
the lock being released for a schedule. The unlock should return the depth
and the lock should restore it, rather than the other way around as it is now.
This patch implements that and adds a number of places where the lock
should be dropped.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index a98b774..881f8ea 100644
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -1340,10 +1340,11 @@
"reading failed", __func__, block);
else {
if (buffer_locked(bh)) {
+ int depth;
PROC_INFO_INC(sb, scan_bitmap.wait);
- reiserfs_write_unlock(sb);
+ depth = reiserfs_write_unlock_nested(sb);
__wait_on_buffer(bh);
- reiserfs_write_lock(sb);
+ reiserfs_write_lock_nested(sb, depth);
}
BUG_ON(!buffer_uptodate(bh));
BUG_ON(atomic_read(&bh->b_count) == 0);