| Message ID | 1432822903-25821-1-git-send-email-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
----- Original Message ----- > Draining is not necessary, I/O can happen as soon as the > commit coroutine yields. Draining can be necessary before > reopening the file for read/write, or while modifying the > backing file chain, but that is done separately in > bdrv_reopen_multiple or bdrv_close; this particular > bdrv_drain_all does nothing for that. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > blockdev.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index d506a70..aee0395 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -2355,9 +2355,6 @@ void qmp_block_commit(const char *device, > aio_context = bdrv_get_aio_context(bs); > aio_context_acquire(aio_context); > > - /* drain all i/o before commits */ > - bdrv_drain_all(); > - Reviewed-by: Fam Zheng <famz@redhat.com> > if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) { > goto out; > } > -- > 2.4.1 > > >
On Thu, May 28, 2015 at 04:21:43PM +0200, Paolo Bonzini wrote: > Draining is not necessary, I/O can happen as soon as the > commit coroutine yields. Draining can be necessary before > reopening the file for read/write, or while modifying the > backing file chain, but that is done separately in > bdrv_reopen_multiple or bdrv_close; this particular > bdrv_drain_all does nothing for that. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > blockdev.c | 3 --- > 1 file changed, 3 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
On Thu, May 28, 2015 at 04:21:43PM +0200, Paolo Bonzini wrote: > Draining is not necessary, I/O can happen as soon as the > commit coroutine yields. Draining can be necessary before > reopening the file for read/write, or while modifying the > backing file chain, but that is done separately in > bdrv_reopen_multiple or bdrv_close; this particular > bdrv_drain_all does nothing for that. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > blockdev.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index d506a70..aee0395 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -2355,9 +2355,6 @@ void qmp_block_commit(const char *device, > aio_context = bdrv_get_aio_context(bs); > aio_context_acquire(aio_context); > > - /* drain all i/o before commits */ > - bdrv_drain_all(); > - > if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) { > goto out; > } > -- > 2.4.1 > Thanks, applied to my block tree: https://github.com/codyprime/qemu-kvm-jtc/commits/block -Jeff
diff --git a/blockdev.c b/blockdev.c index d506a70..aee0395 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2355,9 +2355,6 @@ void qmp_block_commit(const char *device, aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); - /* drain all i/o before commits */ - bdrv_drain_all(); - if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) { goto out; }
Draining is not necessary, I/O can happen as soon as the commit coroutine yields. Draining can be necessary before reopening the file for read/write, or while modifying the backing file chain, but that is done separately in bdrv_reopen_multiple or bdrv_close; this particular bdrv_drain_all does nothing for that. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- blockdev.c | 3 --- 1 file changed, 3 deletions(-)