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authorRobin Ruede <r.ruede@gmail.com>2015-09-30 21:23:33 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-14 21:41:05 -0800
commitb855aa43eb1c47d6e10fd90df2f0fb8ab6423c12 (patch)
tree65c53076dc4b1c5e690ab832828c070382556613
parent36204ef3c3a43e1dc015d2401068e4bfb45e1e09 (diff)
btrfs: fix resending received snapshot with parent
commit b96b1db039ebc584d03a9933b279e0d3e704c528 upstream. This fixes a regression introduced by 37b8d27d between v4.1 and v4.2. When a snapshot is received, its received_uuid is set to the original uuid of the subvolume. When that snapshot is then resent to a third filesystem, it's received_uuid is set to the second uuid instead of the original one. The same was true for the parent_uuid. This behaviour was partially changed in 37b8d27d, but in that patch only the parent_uuid was taken from the real original, not the uuid itself, causing the search for the parent to fail in the case below. This happens for example when trying to send a series of linked snapshots (e.g. created by snapper) from the backup file system back to the original one. The following commands reproduce the issue in v4.2.1 (no error in 4.1.6) # setup three test file systems for i in 1 2 3; do truncate -s 50M fs$i mkfs.btrfs fs$i mkdir $i mount fs$i $i done echo "content" > 1/testfile btrfs su snapshot -r 1/ 1/snap1 echo "changed content" > 1/testfile btrfs su snapshot -r 1/ 1/snap2 # works fine: btrfs send 1/snap1 | btrfs receive 2/ btrfs send -p 1/snap1 1/snap2 | btrfs receive 2/ # ERROR: could not find parent subvolume btrfs send 2/snap1 | btrfs receive 3/ btrfs send -p 2/snap1 2/snap2 | btrfs receive 3/ Signed-off-by: Robin Ruede <rruede+git@gmail.com> Fixes: 37b8d27de5d0 ("Btrfs: use received_uuid of parent during send") Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Ed Tomlinson <edt@aei.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/btrfs/send.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index a739b825bdd3..23bb2e4b911b 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -2353,8 +2353,14 @@ static int send_subvol_begin(struct send_ctx *sctx)
}
TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
- TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
- sctx->send_root->root_item.uuid);
+
+ if (!btrfs_is_empty_uuid(sctx->send_root->root_item.received_uuid))
+ TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
+ sctx->send_root->root_item.received_uuid);
+ else
+ TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
+ sctx->send_root->root_item.uuid);
+
TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
le64_to_cpu(sctx->send_root->root_item.ctransid));
if (parent_root) {