From ebdad913aa9c86a63d3be28b4610e143204c6f3c Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 6 Aug 2013 16:47:48 -0400 Subject: [PATCH] Btrfs: check our parent dir when doing a compare send When doing a send with a parent subvol we will check to see if the file we are acting on is being overwritten and move it if we think it may be needed further down the line during the send. We check this by checking its directory and making sure it existed in the parent and making sure the file existed in the parent. The problem with this check is that if we create a directory and a file in that directory, and then snapshot, and then remove and re-create that same directory and file with different inode numbers and then try to snapshot and send with the original parent we will try and save the original file inside of that directory. This is a problem because during the receive we move the directory out of the way because it is a completely new inode, which makes us unable to find the old file inside of the directory when we try to move that out of the way for the overwrite. We fix this by checking the parent directory of the inode we think we are overwriting. If the parent directory generation in the send root != the parent directory generation in the parent root then we know it is a completely new directory and we need not bother with moving the file out of the way because it would have been completely destroyed. This fixes bz 60673. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/send.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index d3f3b43..0efc2e2 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1668,6 +1668,7 @@ static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen, u64 *who_ino, u64 *who_gen) { int ret = 0; + u64 gen; u64 other_inode = 0; u8 other_type = 0; @@ -1678,6 +1679,24 @@ static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen, if (ret <= 0) goto out; + /* + * If we have a parent root we need to verify that the parent dir was + * not delted and then re-created, if it was then we have no overwrite + * and we can just unlink this entry. + */ + if (sctx->parent_root) { + ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL, + NULL, NULL, NULL); + if (ret < 0 && ret != -ENOENT) + goto out; + if (ret) { + ret = 0; + goto out; + } + if (gen != dir_gen) + goto out; + } + ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len, &other_inode, &other_type); if (ret < 0 && ret != -ENOENT) -- 2.7.4