From 8a57d9d61a6e361c7bb159dda797672c1df1a691 Mon Sep 17 00:00:00 2001 From: Curt Wohlgemuth Date: Sun, 16 May 2010 15:00:00 -0400 Subject: ext4: check for a good block group before loading buddy pages This adds a new field in ext4_group_info to cache the largest available block range in a block group; and don't load the buddy pages until *after* we've done a sanity check on the block group. With large allocation requests (e.g., fallocate(), 8MiB) and relatively full partitions, it's easy to have no block groups with a block extent large enough to satisfy the input request length. This currently causes the loop during cr == 0 in ext4_mb_regular_allocator() to load the buddy bitmap pages for EVERY block group. That can be a lot of pages. The patch below allows us to call ext4_mb_good_group() BEFORE we load the buddy pages (although we have check again after we lock the block group). Addresses-Google-Bug: #2578108 Addresses-Google-Bug: #2704453 Signed-off-by: Curt Wohlgemuth Signed-off-by: "Theodore Ts'o" --- fs/ext4/ext4.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/ext4/ext4.h') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index bf938cf7c5f0..d266003cac3e 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1678,6 +1678,7 @@ struct ext4_group_info { ext4_grpblk_t bb_first_free; /* first free block */ ext4_grpblk_t bb_free; /* total free blocks */ ext4_grpblk_t bb_fragments; /* nr of freespace fragments */ + ext4_grpblk_t bb_largest_free_order;/* order of largest frag in BG */ struct list_head bb_prealloc_list; #ifdef DOUBLE_CHECK void *bb_bitmap; -- cgit v1.2.3