From 61065a30af8df4b8989c2ac7a1f4b4034e4df2d5 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Wed, 25 Apr 2012 16:01:48 -0700 Subject: [PATCH] fs/buffer.c: remove BUG() in possible but rare condition While stressing the kernel with with failing allocations today, I hit the following chain of events: alloc_page_buffers(): bh = alloc_buffer_head(GFP_NOFS); if (!bh) goto no_grow; <= path taken grow_dev_page(): bh = alloc_page_buffers(page, size, 0); if (!bh) goto failed; <= taken, consequence of the above and then the failed path BUG()s the kernel. The failure is inserted a litte bit artificially, but even then, I see no reason why it should be deemed impossible in a real box. Even though this is not a condition that we expect to see around every time, failed allocations are expected to be handled, and BUG() sounds just too much. As a matter of fact, grow_dev_page() can return NULL just fine in other circumstances, so I propose we just remove it, then. Signed-off-by: Glauber Costa Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/buffer.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/buffer.c b/fs/buffer.c index 36d66653b931..351e18ea2e53 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -985,7 +985,6 @@ grow_dev_page(struct block_device *bdev, sector_t block, return page; failed: - BUG(); unlock_page(page); page_cache_release(page); return NULL; -- 2.20.1