Btrfs: Change find_extent_buffer to use TestSetPageLocked
This makes it possible for callers to check for extent_buffers in cache
without deadlocking against any btree locks held.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index bd15cdc..40a5f53 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2808,10 +2808,15 @@
goto lru_add;
for (i = 0; i < num_pages; i++, index++) {
- p = find_lock_page(mapping, index);
+ p = find_get_page(mapping, index);
if (!p) {
goto fail;
}
+ if (TestSetPageLocked(p)) {
+ page_cache_release(p);
+ goto fail;
+ }
+
set_page_extent_mapped(p);
mark_page_accessed(p);