From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dkim1.fusionio.com ([66.114.96.53]:42537 "EHLO dkim1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932951Ab3GKOjU (ORCPT ); Thu, 11 Jul 2013 10:39:20 -0400 Received: from mx2.fusionio.com (unknown [10.101.1.160]) by dkim1.fusionio.com (Postfix) with ESMTP id 6ABCB7C0417 for ; Thu, 11 Jul 2013 08:39:19 -0600 (MDT) Received: from CAS1.int.fusionio.com (cas1.int.fusionio.com [10.101.1.40]) by mx2.fusionio.com with ESMTP id HG3YZxuH0LxOBLna (version=TLSv1 cipher=AES128-SHA bits=128 verify=NO) for ; Thu, 11 Jul 2013 08:39:18 -0600 (MDT) From: Josef Bacik To: Subject: [PATCH] Btrfs: allow splitting of hole em's when dropping extent cache Date: Thu, 11 Jul 2013 10:39:16 -0400 Message-ID: <1373553556-18927-1-git-send-email-jbacik@fusionio.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: I noticed while running multi-threaded fsync tests that sometimes fsck would complain about an improper gap. This happens because we fail to add a hole extent to the file, which was happening when we'd split a hole EM because btrfs_drop_extent_cache was just discarding the whole em instead of splitting it. So this patch fixes this by allowing us to split a hole em properly, which means that added holes actually get logged properly and we no longer see this fsck error. Thankfully we're tolerant of these sort of problems so a user would not see any adverse effects of this bug, other than fsck complaining. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/file.c | 62 +++++++++++++++++++++++++++++++++++------------------- 1 files changed, 40 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 2d70849..dda2efb 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -595,20 +595,29 @@ void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, if (no_splits) goto next; - if (em->block_start < EXTENT_MAP_LAST_BYTE && - em->start < start) { + if (em->start < start) { split->start = em->start; split->len = start - em->start; - split->orig_start = em->orig_start; - split->block_start = em->block_start; - if (compressed) - split->block_len = em->block_len; - else - split->block_len = split->len; - split->ram_bytes = em->ram_bytes; - split->orig_block_len = max(split->block_len, - em->orig_block_len); + if (em->block_start < EXTENT_MAP_LAST_BYTE) { + split->orig_start = em->orig_start; + split->block_start = em->block_start; + + if (compressed) + split->block_len = em->block_len; + else + split->block_len = split->len; + split->orig_block_len = max(split->block_len, + em->orig_block_len); + split->ram_bytes = em->ram_bytes; + } else { + split->orig_start = split->start; + split->block_len = 0; + split->block_start = em->block_start; + split->orig_block_len = 0; + split->ram_bytes = split->len; + } + split->generation = gen; split->bdev = em->bdev; split->flags = flags; @@ -619,8 +628,7 @@ void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, split = split2; split2 = NULL; } - if (em->block_start < EXTENT_MAP_LAST_BYTE && - testend && em->start + em->len > start + len) { + if (testend && em->start + em->len > start + len) { u64 diff = start + len - em->start; split->start = start + len; @@ -629,18 +637,28 @@ void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, split->flags = flags; split->compress_type = em->compress_type; split->generation = gen; - split->orig_block_len = max(em->block_len, + + if (em->block_start < EXTENT_MAP_LAST_BYTE) { + split->orig_block_len = max(em->block_len, em->orig_block_len); - split->ram_bytes = em->ram_bytes; - if (compressed) { - split->block_len = em->block_len; - split->block_start = em->block_start; - split->orig_start = em->orig_start; + split->ram_bytes = em->ram_bytes; + if (compressed) { + split->block_len = em->block_len; + split->block_start = em->block_start; + split->orig_start = em->orig_start; + } else { + split->block_len = split->len; + split->block_start = em->block_start + + diff; + split->orig_start = em->orig_start; + } } else { - split->block_len = split->len; - split->block_start = em->block_start + diff; - split->orig_start = em->orig_start; + split->ram_bytes = split->len; + split->orig_start = split->start; + split->block_len = 0; + split->block_start = em->block_start; + split->orig_block_len = 0; } ret = add_extent_mapping(em_tree, split, modified); -- 1.7.7.6