From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from acsinet15.oracle.com ([141.146.126.227]:43315 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754576Ab2JWPae (ORCPT ); Tue, 23 Oct 2012 11:30:34 -0400 Message-ID: <5086B81C.5070901@oracle.com> Date: Tue, 23 Oct 2012 23:30:36 +0800 From: Liu Bo MIME-Version: 1.0 To: Jan Schmidt CC: chris.mason@fusionio.com, linux-btrfs@vger.kernel.org Subject: Re: [PATCH 3/6] Btrfs: tree mod log's old roots could still be part of the tree References: <1351000527-24952-1-git-send-email-list.btrfs@jan-o-sch.net> <1351000527-24952-4-git-send-email-list.btrfs@jan-o-sch.net> In-Reply-To: <1351000527-24952-4-git-send-email-list.btrfs@jan-o-sch.net> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 10/23/2012 09:55 PM, Jan Schmidt wrote: > Tree mod log treated old root buffers as always empty buffers when starting > the rewind operations. However, the old root may still be part of the > current tree at a lower level, with still some valid entries. > Reviewed-by: Liu Bo Tested-by: Liu Bo thanks, liubo > Signed-off-by: Jan Schmidt > --- > fs/btrfs/ctree.c | 16 ++++++++++++++-- > 1 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c > index e6b75cc..1b60c56 100644 > --- a/fs/btrfs/ctree.c > +++ b/fs/btrfs/ctree.c > @@ -1239,6 +1239,7 @@ get_old_root(struct btrfs_root *root, u64 time_seq) > struct tree_mod_root *old_root = NULL; > u64 old_generation = 0; > u64 logical; > + u32 blocksize; > > eb = btrfs_read_lock_root_node(root); > tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); > @@ -1254,10 +1255,21 @@ get_old_root(struct btrfs_root *root, u64 time_seq) > } > > tm = tree_mod_log_search(root->fs_info, logical, time_seq); > - if (old_root) > + if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { > + blocksize = btrfs_level_size(root, old_root->level); > + eb = read_tree_block(root, logical, blocksize, 0); > + if (!eb) { > + pr_warn("btrfs: failed to read tree block %llu from get_old_root\n", > + logical); > + WARN_ON(1); > + } else { > + eb = btrfs_clone_extent_buffer(eb); > + } > + } else if (old_root) { > eb = alloc_dummy_extent_buffer(logical, root->nodesize); > - else > + } else { > eb = btrfs_clone_extent_buffer(root->node); > + } > btrfs_tree_read_unlock(root->node); > free_extent_buffer(root->node); > if (!eb) >