From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:55476 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751807Ab3H3CR3 (ORCPT ); Thu, 29 Aug 2013 22:17:29 -0400 Message-ID: <5220003F.6090103@cn.fujitsu.com> Date: Fri, 30 Aug 2013 10:15:27 +0800 From: Wang Shilong MIME-Version: 1.0 To: Josef Bacik CC: linux-btrfs@vger.kernel.org Subject: Re: [PATCH] Btrfs: fix send to deal with sparse files properly V2 References: <1377186470-4000-1-git-send-email-jbacik@fusionio.com> In-Reply-To: <1377186470-4000-1-git-send-email-jbacik@fusionio.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 08/22/2013 11:47 PM, Josef Bacik wrote: please use checkpatch.pl to check coding styles before sending patches: WARNING: line over 80 characters #86: FILE: fs/btrfs/send.c:4051: + if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) { total: 0 errors, 1 warnings, 59 lines checked Thanks, Wang > Send was just sending everything it found, even if the extent was a hole. This > is unpleasant for users, so just skip holes when we are sending. This will also > skip sending prealloc extents since the send spec doesn't have a prealloc > command. Eventually we will add a prealloc command and rev the send version so > we can send down the prealloc info. Thanks, > > Signed-off-by: Josef Bacik > --- > V1->V2: fix where we were skipping holes that needed to be written because we > punched a hole between the original snapshot and the send snapshot. > > fs/btrfs/send.c | 34 +++++++++++++++++++++++++++++++--- > 1 files changed, 31 insertions(+), 3 deletions(-) > > diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c > index db7da68..cbe92da 100644 > --- a/fs/btrfs/send.c > +++ b/fs/btrfs/send.c > @@ -3920,7 +3920,8 @@ static int is_extent_unchanged(struct send_ctx *sctx, > btrfs_item_key_to_cpu(eb, &found_key, slot); > if (found_key.objectid != key.objectid || > found_key.type != key.type) { > - ret = 0; > + /* If we're a hole then just pretend nothing changed */ > + ret = (left_disknr) ? 0 : 1; > goto out; > } > > @@ -3946,7 +3947,8 @@ static int is_extent_unchanged(struct send_ctx *sctx, > * This may only happen on the first iteration. > */ > if (found_key.offset + right_len <= ekey->offset) { > - ret = 0; > + /* If we're a hole just pretend nothing changed */ > + ret = (left_disknr) ? 0 : 1; > goto out; > } > > @@ -4011,8 +4013,8 @@ static int process_extent(struct send_ctx *sctx, > struct btrfs_path *path, > struct btrfs_key *key) > { > - int ret = 0; > struct clone_root *found_clone = NULL; > + int ret = 0; > > if (S_ISLNK(sctx->cur_inode_mode)) > return 0; > @@ -4025,6 +4027,32 @@ static int process_extent(struct send_ctx *sctx, > ret = 0; > goto out; > } > + } else { > + struct btrfs_file_extent_item *ei; > + u8 type; > + > + ei = btrfs_item_ptr(path->nodes[0], path->slots[0], > + struct btrfs_file_extent_item); > + type = btrfs_file_extent_type(path->nodes[0], ei); > + if (type == BTRFS_FILE_EXTENT_PREALLOC || > + type == BTRFS_FILE_EXTENT_REG) { > + /* > + * The send spec does not have a prealloc command yet, > + * so just leave a hole for prealloc'ed extents until > + * we have enough commands queued up to justify rev'ing > + * the send spec. > + */ > + if (type == BTRFS_FILE_EXTENT_PREALLOC) { > + ret = 0; > + goto out; > + } > + > + /* Have a hole, just skip it. */ > + if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) { > + ret = 0; > + goto out; > + } > + } > } > > ret = find_extent_clone(sctx, path, key->objectid, key->offset,