From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57630) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zz3Gu-0003v5-63 for qemu-devel@nongnu.org; Wed, 18 Nov 2015 08:59:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zz3Gq-0007k0-3E for qemu-devel@nongnu.org; Wed, 18 Nov 2015 08:59:40 -0500 Received: from e06smtp17.uk.ibm.com ([195.75.94.113]:41284) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zz3Gp-0007jl-QU for qemu-devel@nongnu.org; Wed, 18 Nov 2015 08:59:36 -0500 Received: from localhost by e06smtp17.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 18 Nov 2015 13:59:33 -0000 Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 3266A2190067 for ; Wed, 18 Nov 2015 13:59:24 +0000 (GMT) Received: from d06av08.portsmouth.uk.ibm.com (d06av08.portsmouth.uk.ibm.com [9.149.37.249]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tAIDxTOm45744318 for ; Wed, 18 Nov 2015 13:59:29 GMT Received: from d06av08.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av08.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tAIDxTdI009325 for ; Wed, 18 Nov 2015 06:59:29 -0700 Date: Wed, 18 Nov 2015 14:59:26 +0100 From: Greg Kurz Message-ID: <20151118145926.567075a4@bahia.local> In-Reply-To: <1447751311-2317-12-git-send-email-den@openvz.org> References: <1447751311-2317-1-git-send-email-den@openvz.org> <1447751311-2317-12-git-send-email-den@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 11/11] migration: normalize locking in migration/savevm.c List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Denis V. Lunev" Cc: Kevin Wolf , qemu-devel@nongnu.org, stefanha@redhat.com, Juan Quintela On Tue, 17 Nov 2015 12:08:31 +0300 "Denis V. Lunev" wrote: > basically all bdrv_* operations must be called under aio_context_acquire > except ones with bdrv_all prefix. > > Signed-off-by: Denis V. Lunev > Reviewed-by: Stefan Hajnoczi > Reviewed-by: Fam Zheng > CC: Juan Quintela > CC: Kevin Wolf > --- > migration/savevm.c | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > > diff --git a/migration/savevm.c b/migration/savevm.c > index a845e69..09e6a43 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -1917,6 +1917,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict) > struct tm tm; > const char *name = qdict_get_try_str(qdict, "name"); > Error *local_err = NULL; > + AioContext *aio_context; > > if (!bdrv_all_can_snapshot(&bs)) { > monitor_printf(mon, "Device '%s' is writable but does not " > @@ -1938,6 +1939,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict) > monitor_printf(mon, "No block device can accept snapshots\n"); > return; > } > + aio_context = bdrv_get_aio_context(bs); > > saved_vm_running = runstate_is_running(); > > @@ -1948,6 +1950,8 @@ void hmp_savevm(Monitor *mon, const QDict *qdict) > } > vm_stop(RUN_STATE_SAVE_VM); > > + aio_context_acquire(aio_context); > + > memset(sn, 0, sizeof(*sn)); > > /* fill auxiliary fields */ > @@ -1992,6 +1996,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict) > } > > the_end: > + aio_context_release(aio_context); > if (saved_vm_running) { > vm_start(); > } > @@ -2030,6 +2035,7 @@ int load_vmstate(const char *name) > QEMUSnapshotInfo sn; > QEMUFile *f; > int ret; > + AioContext *aio_context; > > if (!bdrv_all_can_snapshot(&bs)) { > error_report("Device '%s' is writable but does not support snapshots.", > @@ -2048,9 +2054,12 @@ int load_vmstate(const char *name) > error_report("No block device supports snapshots"); > return -ENOTSUP; > } > + aio_context = bdrv_get_aio_context(bs); > bs is used for error reporting earlier in this function. bs_vm_state is the one to be used here. > /* Don't even try to load empty VM states */ > + aio_context_acquire(aio_context); > ret = bdrv_snapshot_find(bs_vm_state, &sn, name); > + aio_context_release(aio_context); > if (ret < 0) { > return ret; > } else if (sn.vm_state_size == 0) { > @@ -2078,9 +2087,12 @@ int load_vmstate(const char *name) > > qemu_system_reset(VMRESET_SILENT); > migration_incoming_state_new(f); > - ret = qemu_loadvm_state(f); > > + aio_context_acquire(aio_context); > + ret = qemu_loadvm_state(f); > qemu_fclose(f); > + aio_context_release(aio_context); > + > migration_incoming_state_destroy(); > if (ret < 0) { > error_report("Error %d while loading VM state", ret); > @@ -2111,14 +2123,19 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict) > int nb_sns, i; > int total; > int *available_snapshots; > + AioContext *aio_context; > > bs = bdrv_all_find_vmstate_bs(); > if (!bs) { > monitor_printf(mon, "No available block device supports snapshots\n"); > return; > } > + aio_context = bdrv_get_aio_context(bs); > > + aio_context_acquire(aio_context); > nb_sns = bdrv_snapshot_list(bs, &sn_tab); > + aio_context_release(aio_context); > + > if (nb_sns < 0) { > monitor_printf(mon, "bdrv_snapshot_list: error %d\n", nb_sns); > return;