| Message ID | 149095962044.26233.2156597686399438923.stgit@bahia.lan |
|---|---|
| State | New |
| Headers | show |
> -----Original Message----- > From: Greg Kurz [mailto:groug@kaod.org] > Sent: Friday, March 31, 2017 7:27 PM > To: qemu-devel@nongnu.org > Cc: Eric Blake; 李强; Greg Kurz > Subject: [for-2.9 PATCH 1/3] 9pfs: clear migration blocker at session reset > > The migration blocker survives a device reset: if the guest mounts a 9p share > and then gets rebooted with system_reset, it will be unmigratable until it > remounts and umounts the 9p share again. > > This happens because the migration blocker is supposed to be cleared when we > put the last reference on the root fid, but virtfs_reset() wrongly calls > free_fid() instead of put_fid(). > > This patch fixes virtfs_reset() so that it honor the way fids are supposed to be > manipulated: first get a reference and later put it back when you're done. > > Signed-off-by: Greg Kurz <groug@kaod.org> > --- Reviewed-by: Li Qiang <liqiang6-s@360.cn> > hw/9pfs/9p.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 48babce836b6..cc109367b030 > 100644 > --- a/hw/9pfs/9p.c > +++ b/hw/9pfs/9p.c > @@ -539,14 +539,15 @@ static void coroutine_fn virtfs_reset(V9fsPDU *pdu) > > /* Free all fids */ > while (s->fid_list) { > + /* Get fid */ > fidp = s->fid_list; > + fidp->ref++; > + > + /* Clunk fid */ > s->fid_list = fidp->next; > + fidp->clunked = 1; > > - if (fidp->ref) { > - fidp->clunked = 1; > - } else { > - free_fid(pdu, fidp); > - } > + put_fid(pdu, fidp); > } > } >
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 48babce836b6..cc109367b030 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -539,14 +539,15 @@ static void coroutine_fn virtfs_reset(V9fsPDU *pdu) /* Free all fids */ while (s->fid_list) { + /* Get fid */ fidp = s->fid_list; + fidp->ref++; + + /* Clunk fid */ s->fid_list = fidp->next; + fidp->clunked = 1; - if (fidp->ref) { - fidp->clunked = 1; - } else { - free_fid(pdu, fidp); - } + put_fid(pdu, fidp); } }
The migration blocker survives a device reset: if the guest mounts a 9p share and then gets rebooted with system_reset, it will be unmigratable until it remounts and umounts the 9p share again. This happens because the migration blocker is supposed to be cleared when we put the last reference on the root fid, but virtfs_reset() wrongly calls free_fid() instead of put_fid(). This patch fixes virtfs_reset() so that it honor the way fids are supposed to be manipulated: first get a reference and later put it back when you're done. Signed-off-by: Greg Kurz <groug@kaod.org> --- hw/9pfs/9p.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)