| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.1 040/267] ext4: replace open coded nofail allocation in ext4_free_blocks() | Date | Fri, 31 Jul 2015 12:38:11 -0700 |
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4.1-stable review patch. If anyone has any objections, please let me know.
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From: Michal Hocko <mhocko@suse.cz>
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 <mhocko@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/ext4/mballoc.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-)
--- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4800,18 +4800,12 @@ 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;
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