Il 13/02/2013 13:55, Stefan Priebe - Profihost AG ha scritto:
> Hi,
> Am 13.02.2013 12:36, schrieb Paolo Bonzini:
>> Il 13/02/2013 10:07, Stefan Priebe - Profihost AG ha scritto:
>>>>>>>
>>>>>>> commit 47a150a4bbb06e45ef439a8222e9f46a7c4cca3f
>>> ...
>>>>> You can certainly try reverting it, but this patch is fixing a real bug.
>>> Will try that. Yes but even if it fixes a bug and raises another one
>>> (kvm segfault) which is the worst one. It should be fixed.
>>
>> The KVM segfault is exposing a potential consistency problem. What is
>> worse is not obvious. Also, it is happening at reset time if this is
>> the culprit. Reset usually happens at places where no data loss is caused.
>>
>> Can you find out what the VM was doing when it segfaulted? (Or even,
>> can you place the corefile and kvm executable somewhere where I can
>> download it?)
>
> Yes it was doing an fstrim -v / which resulted in:
>
> [45648.453698] end_request: I/O error, dev sda, sector 9066952
Ok, very helpful. One thing is to find why this failed. This can
come later though.
First of all, please run "cat /sys/block/*/device/scsi_disk/*/provisioning_mode"
in a VM with a similar configuration as the one that crashed last.
Second, I attach another patch.
Third, if possible please compile QEMU with --enable-trace-backend=simple,
and run it with
-trace events='bdrv_aio_discard
scsi_req_cancel
',file=qemu.$$.trace
This can give some clues. The files should remain quite small,
so you can enable it on all VMs safely.
> Sadly not as i don't have acore dump. The kvm processes are started
> through variuos Daemons and there seems no way to activate core dumps
> for an already running process and i don't know which VM will crash next.
Probably the next that invokes fstrim. :)
>> If not, do your VMs reset themselves
>> often for example?
> No
Ok, good to know.
>> Can you reproduce it on non-rbd storage?
> I don't have another storage type. ;-(
No problem.
Paolo
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index a97f1cd..01e1dec 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -1508,6 +1508,10 @@ void scsi_req_unref(SCSIRequest *req)
will start the next chunk or complete the command. */
void scsi_req_continue(SCSIRequest *req)
{
+ if (req->io_canceled) {
+ trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
+ return;
+ }
trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
if (req->cmd.mode == SCSI_XFER_TO_DEV) {
req->ops->write_data(req);
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index d411586..4a0673c 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -178,6 +178,9 @@ static void scsi_aio_complete(void *opaque, int ret)
assert(r->req.aiocb != NULL);
r->req.aiocb = NULL;
bdrv_acct_done(s->qdev.conf.bs, &r->acct);
+ if (r->req.io_canceled) {
+ goto done;
+ }
if (ret < 0) {
if (scsi_handle_rw_error(r, -ret)) {
@@ -223,6 +226,10 @@ static void scsi_write_do_fua(SCSIDiskReq *r)
{
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
+ if (r->req.io_canceled) {
+ goto done;
+ }
+
if (scsi_is_cmd_fua(&r->req.cmd)) {
bdrv_acct_start(s->qdev.conf.bs, &r->acct, 0, BDRV_ACCT_FLUSH);
r->req.aiocb = bdrv_aio_flush(s->qdev.conf.bs, scsi_aio_complete, r);
@@ -230,6 +237,8 @@ static void scsi_write_do_fua(SCSIDiskReq *r)
}
scsi_req_complete(&r->req, GOOD);
+
+done:
if (!r->req.io_canceled) {
scsi_req_unref(&r->req);
}
@@ -243,6 +252,9 @@ static void scsi_dma_complete(void *opaque, int ret)
assert(r->req.aiocb != NULL);
r->req.aiocb = NULL;
bdrv_acct_done(s->qdev.conf.bs, &r->acct);
+ if (r->req.io_canceled) {
+ goto done;
+ }
if (ret < 0) {
if (scsi_handle_rw_error(r, -ret)) {
@@ -274,6 +286,9 @@ static void scsi_read_complete(void * opaque, int ret)
assert(r->req.aiocb != NULL);
r->req.aiocb = NULL;
bdrv_acct_done(s->qdev.conf.bs, &r->acct);
+ if (r->req.io_canceled) {
+ goto done;
+ }
if (ret < 0) {
if (scsi_handle_rw_error(r, -ret)) {
@@ -305,6 +320,9 @@ static void scsi_do_read(void *opaque, int ret)
r->req.aiocb = NULL;
bdrv_acct_done(s->qdev.conf.bs, &r->acct);
}
+ if (r->req.io_canceled) {
+ goto done;
+ }
if (ret < 0) {
if (scsi_handle_rw_error(r, -ret)) {
@@ -312,10 +330,6 @@ static void scsi_do_read(void *opaque, int ret)
}
}
- if (r->req.io_canceled) {
- return;
- }
-
/* The request is used as the AIO opaque value, so add a ref. */
scsi_req_ref(&r->req);
@@ -423,6 +437,9 @@ static void scsi_write_complete(void * opaque, int ret)
r->req.aiocb = NULL;
bdrv_acct_done(s->qdev.conf.bs, &r->acct);
}
+ if (r->req.io_canceled) {
+ goto done;
+ }
if (ret < 0) {
if (scsi_handle_rw_error(r, -ret)) {
@@ -1478,13 +1495,17 @@ static void scsi_unmap_complete(void *opaque, int ret)
uint32_t nb_sectors;
r->req.aiocb = NULL;
+ if (r->req.io_canceled) {
+ goto done;
+ }
+
if (ret < 0) {
if (scsi_handle_rw_error(r, -ret)) {
goto done;
}
}
- if (data->count > 0 && !r->req.io_canceled) {
+ if (data->count > 0) {
sector_num = ldq_be_p(&data->inbuf[0]);
nb_sectors = ldl_be_p(&data->inbuf[8]) & 0xffffffffULL;
if (!check_lba_range(s, sector_num, nb_sectors)) {
@@ -1501,10 +1522,9 @@ static void scsi_unmap_complete(void *opaque, int ret)
return;
}
+ scsi_req_complete(&r->req, GOOD);
+
done:
- if (data->count == 0) {
- scsi_req_complete(&r->req, GOOD);
- }
if (!r->req.io_canceled) {
scsi_req_unref(&r->req);
}
diff --git a/roms/seabios b/roms/seabios
index 4bd8aeb..e8a76b0 160000
--- a/roms/seabios
+++ b/roms/seabios
@@ -1 +1 @@
-Subproject commit 4bd8aebf3534e10d9aa21e820903f2cf9120708c
+Subproject commit e8a76b0f225bba5ba9d63ab227e0a37b3beb1059
diff --git a/trace-events b/trace-events
index f2c256c..a42497c 100644
--- a/trace-events
+++ b/trace-events
@@ -461,6 +461,7 @@ scsi_req_data(int target, int lun, int tag, int len) "target %d lun %d tag %d le
scsi_req_data_canceled(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d"
scsi_req_dequeue(int target, int lun, int tag) "target %d lun %d tag %d"
scsi_req_continue(int target, int lun, int tag) "target %d lun %d tag %d"
+scsi_req_continue_canceled(int target, int lun, int tag) "target %d lun %d tag %d"
scsi_req_parsed(int target, int lun, int tag, int cmd, int mode, int xfer) "target %d lun %d tag %d command %d dir %d length %d"
scsi_req_parsed_lba(int target, int lun, int tag, int cmd, uint64_t lba) "target %d lun %d tag %d command %d lba %"PRIu64
scsi_req_parse_bad(int target, int lun, int tag, int cmd) "target %d lun %d tag %d command %d"
