On Tue, Jul 23, 2019 at 12:19 PM Filipe Manana <fdmanana@xxxxxxxxx> wrote:
>
> On Tue, Jul 23, 2019 at 3:25 AM Omar Sandoval <osandov@xxxxxxxxxxx> wrote:
> >
> > From: Omar Sandoval <osandov@xxxxxx>
> >
> > When we process a clone request, we look up the source subvolume by
> > UUID, even if the source is the subvolume that we're currently
> > receiving. Usually, this is fine. However, if for some reason we
> > previously received the same subvolume, then this will use paths
> > relative to the previously received subvolume instead of the current
> > one. This is incorrect, since the send stream may use temporary names
> > for the clone source. This can be reproduced as follows:
> >
> > btrfs subvolume create subvol
> > dd if=/dev/urandom of=subvol/foo bs=1M count=1
> > cp --reflink subvol/foo subvol/bar
> > mkdir subvol/dir
> > mv subvol/foo subvol/dir/
> > btrfs property set subvol ro true
> > btrfs send -f send.data subvol
> > mkdir first second
> > btrfs receive -f send.data first
> > btrfs receive -f send.data second
> >
> > The second receive results in this error:
> >
> > ERROR: cannot open first/subvol/o259-7-0/foo: No such file or directory
> >
> > Fix it by always cloning from the current subvolume if its UUID matches.
> > This has the nice side effect of avoiding unnecessary UUID tree lookups
> > in that case.
> >
> > Fixes: f1c24cd80dfd ("Btrfs-progs: add btrfs send/receive commands")
> > Signed-off-by: Omar Sandoval <osandov@xxxxxx>
>
> Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
I can't find this patch in btrfs-progs. Any reason why it was never applied?
thanks
>
> Thanks!
>
> > ---
> > cmds/receive.c | 18 ++++++++----------
> > 1 file changed, 8 insertions(+), 10 deletions(-)
> >
> > diff --git a/cmds/receive.c b/cmds/receive.c
> > index dba05982..1e6a29dd 100644
> > --- a/cmds/receive.c
> > +++ b/cmds/receive.c
> > @@ -744,15 +744,14 @@ static int process_clone(const char *path, u64 offset, u64 len,
> > if (ret < 0)
> > goto out;
> >
> > - si = subvol_uuid_search(&rctx->sus, 0, clone_uuid, clone_ctransid,
> > - NULL,
> > - subvol_search_by_received_uuid);
> > - if (IS_ERR_OR_NULL(si)) {
> > - if (memcmp(clone_uuid, rctx->cur_subvol.received_uuid,
> > - BTRFS_UUID_SIZE) == 0) {
> > - /* TODO check generation of extent */
> > - subvol_path = rctx->cur_subvol_path;
> > - } else {
> > + if (memcmp(clone_uuid, rctx->cur_subvol.received_uuid,
> > + BTRFS_UUID_SIZE) == 0) {
> > + subvol_path = rctx->cur_subvol_path;
> > + } else {
> > + si = subvol_uuid_search(&rctx->sus, 0, clone_uuid, clone_ctransid,
> > + NULL,
> > + subvol_search_by_received_uuid);
> > + if (IS_ERR_OR_NULL(si)) {
> > if (!si)
> > ret = -ENOENT;
> > else
> > @@ -760,7 +759,6 @@ static int process_clone(const char *path, u64 offset, u64 len,
> > error("clone: did not find source subvol");
> > goto out;
> > }
> > - } else {
> > /* strip the subvolume that we are receiving to from the start of subvol_path */
> > if (rctx->full_root_path) {
> > size_t root_len = strlen(rctx->full_root_path);
> > --
> > 2.22.0
> >
>
>
> --
> Filipe David Manana,
>
> “Whether you think you can, or you think you can't — you're right.”
--
Filipe David Manana,
“Whether you think you can, or you think you can't — you're right.”
