[lkml]   [2018]   [May]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 4.4 120/268] Btrfs: send, fix issuing write op when processing hole in no data mode
4.4-stable review patch.  If anyone has any objections, please let me know.


From: Filipe Manana <>

[ Upstream commit d4dfc0f4d39475ccbbac947880b5464a74c30b99 ]

When doing an incremental send of a filesystem with the no-holes feature
enabled, we end up issuing a write operation when using the no data mode
send flag, instead of issuing an update extent operation. Fix this by
issuing the update extent operation instead.

Trivial reproducer:

$ mkfs.btrfs -f -O no-holes /dev/sdc
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdc /mnt/sdc
$ mount /dev/sdd /mnt/sdd

$ xfs_io -f -c "pwrite -S 0xab 0 32K" /mnt/sdc/foobar
$ btrfs subvolume snapshot -r /mnt/sdc /mnt/sdc/snap1

$ xfs_io -c "fpunch 8K 8K" /mnt/sdc/foobar
$ btrfs subvolume snapshot -r /mnt/sdc /mnt/sdc/snap2

$ btrfs send /mnt/sdc/snap1 | btrfs receive /mnt/sdd
$ btrfs send --no-data -p /mnt/sdc/snap1 /mnt/sdc/snap2 \
| btrfs receive -vv /mnt/sdd

Before this change the output of the second receive command is:

receiving snapshot snap2 uuid=f6922049-8c22-e544-9ff9-fc6755918447...
write foobar, offset 8192, len 8192
utimes foobar
BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=f6922049-8c22-e544-9ff9-...

After this change it is:

receiving snapshot snap2 uuid=564d36a3-ebc8-7343-aec9-bf6fda278e64...
update_extent foobar: offset=8192, len=8192
utimes foobar
BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=564d36a3-ebc8-7343-aec9-bf6fda278e64...

Signed-off-by: Filipe Manana <>
Signed-off-by: David Sterba <>
Signed-off-by: Sasha Levin <>
Signed-off-by: Greg Kroah-Hartman <>
fs/btrfs/send.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -4674,6 +4674,9 @@ static int send_hole(struct send_ctx *sc
u64 len;
int ret = 0;

+ if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
+ return send_update_extent(sctx, offset, end - offset);
p = fs_path_alloc();
if (!p)
return -ENOMEM;

 \ /
  Last update: 2018-05-28 12:19    [W:0.730 / U:1.404 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site