Hello Michael,
On 12/18/2013 11:29 AM, Michael Welsh Duggan wrote:
Miao Xie <mi...@cn.fujitsu.com> writes:
On Tue, 17 Dec 2013 10:40:41 -0500, Michael Welsh Duggan wrote:
David Sterba <dste...@suse.cz> writes:
On Tue, Dec 17, 2013 at 05:13:49PM +0800, Wang Shilong wrote:
If we change our default subvolume, btrfs receive will fail to find
subvolume. To fix this problem, i have two ideas.
1.make btrfs snapshot ioctl support passing source subvolume's
objectid
2.when we want to using interval subvolume path, we mount it other
place
that use subvolume 5 as its default subvolume.
3. Tell the user to mount the toplevel subvol by himself and run
receive
again
Ugh. I hope that would be considered a short-term hack waiting for a
better solution, perhaps requiring a kernel upgrade. From a user's
perspective there is no reason this should be necessary, and requiring
this would be extraordinarily surprising. "Why is btrfs unable to find
my snapshot? It's right there!" Moreover, this used to work just fine
in previous versions of btrfs-progs.
Though the snapshot is still in the fs, it is inaccessible because you
mount
some subvolume as the root, and you can not find the path to the snapshot.
For example:
There are two subvolumes in the fs, and they are in the root directory
of the
fs, just like
real root directory
|->subv0
|->subv1
Then if you mount the subv1 as the root directory, the real root
directory of
the fs and subv0 will be shielded,
+-------------------+
|real root directory|
| |->subv0 |
+-------------------+
|->subv1
you can only access the files, directories, subvolumes... in the subv1. So the
tool
will report "can not find ...."
BTW, it is impossible that the previous version of btrfs-progs can work well in
this case.
In that case I either misunderstand completely, or my problem is almost
decidedly different. To recap, this is the command that failed:
# ./btrfs send -p /snapshots/bo /snapshots/bp | ./btrfs receive
/backup/snapshots/root/
At subvol /snapshots/bp
At snapshot bp
ioctl(BTRFS_IOC_TREE_SEARCH, uuid, key 48f0ebae83fd32f1, UUID_KEY,
90139d8200afeaab) ret=-1, error: No such file or directory
ioctl(BTRFS_IOC_TREE_SEARCH, uuid, key 48f0ebae83fd32f1, UUID_KEY,
90139d8200afeaab) ret=-1, error: No such file or directory
ERROR: could not find parent subvolume
It seems that you use older kernel version but use the latest
btrfs-progs, new btrfs-progs use uuid tree to search but
this tree did not exist yet.
Can you try to upgrade your kernel?
Thanks,
Wang
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