From: Michal Hocko Date: Sun, 5 Jul 2015 16:33:44 +0000 (-0400) Subject: ext4: replace open coded nofail allocation in ext4_free_blocks() X-Git-Tag: v3.4.111~102 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cfba310a0369d8d5e9b7c3718c749836021ee4e2;p=thirdparty%2Fkernel%2Fstable.git ext4: replace open coded nofail allocation in ext4_free_blocks() commit 7444a072c387a93ebee7066e8aee776954ab0e41 upstream. ext4_free_blocks is looping around the allocation request and mimics __GFP_NOFAIL behavior without any allocation fallback strategy. Let's remove the open coded loop and replace it with __GFP_NOFAIL. Without the flag the allocator has no way to find out never-fail requirement and cannot help in any way. Signed-off-by: Michal Hocko Signed-off-by: Theodore Ts'o Signed-off-by: Zefan Li --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index cdfc763b313fc..46e6562ae66e8 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4643,18 +4643,12 @@ do_more: /* * blocks being freed are metadata. these blocks shouldn't * be used until this transaction is committed + * + * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed + * to fail. */ - retry: - new_entry = kmem_cache_alloc(ext4_free_data_cachep, GFP_NOFS); - if (!new_entry) { - /* - * We use a retry loop because - * ext4_free_blocks() is not allowed to fail. - */ - cond_resched(); - congestion_wait(BLK_RW_ASYNC, HZ/50); - goto retry; - } + new_entry = kmem_cache_alloc(ext4_free_data_cachep, + GFP_NOFS|__GFP_NOFAIL); new_entry->efd_start_cluster = bit; new_entry->efd_group = block_group; new_entry->efd_count = count_clusters;