Btrfs: avoid NULL pointer deref in try_release_extent_buffer

If we fail to find a pointer in the radix tree, don't try
to deref the NULL one we do have.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2010-11-21 22:27:44 -05:00
parent a1b075d28d
commit 45f49bce99

View File

@ -3837,8 +3837,10 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
spin_lock(&tree->buffer_lock);
eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
if (!eb)
goto out;
if (!eb) {
spin_unlock(&tree->buffer_lock);
return ret;
}
if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
ret = 0;