From: Stefan Priebe <s.priebe@profihost.ag>
To: qemu-devel@nongnu.org
Cc: Stefan Priebe <s.priebe@profihost.ag>,
Stefan Priebe <s.priebe@profhost.ag>
Subject: [Qemu-devel] [PATCH] rbd block driver fix race between aio completition and aio cancel
Date: Mon, 19 Nov 2012 21:39:45 +0100 [thread overview]
Message-ID: <1353357585-31746-2-git-send-email-s.priebe@profihost.ag> (raw)
In-Reply-To: <1353357585-31746-1-git-send-email-s.priebe@profihost.ag>
From: Stefan Priebe <s.priebe@profhost.ag>
This one fixes a race qemu also had in iscsi block driver between
cancellation and io completition.
qemu_rbd_aio_cancel was not synchronously waiting for the end of
the command.
It also removes the useless cancelled flag and introduces instead
a status flag with EINPROGRESS like iscsi block driver.
Signed-off-by: Stefan Priebe <s.priebe@profihost.ag>
---
block/rbd.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/block/rbd.c b/block/rbd.c
index 5a0f79f..7b3bcbb 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -76,7 +76,7 @@ typedef struct RBDAIOCB {
int64_t sector_num;
int error;
struct BDRVRBDState *s;
- int cancelled;
+ int status;
} RBDAIOCB;
typedef struct RADOSCB {
@@ -376,9 +376,7 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb)
RBDAIOCB *acb = rcb->acb;
int64_t r;
- if (acb->cancelled) {
- qemu_vfree(acb->bounce);
- qemu_aio_release(acb);
+ if (acb->bh) {
goto done;
}
@@ -406,9 +404,12 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb)
acb->ret = r;
}
}
+ acb->status = acb->ret;
+
/* Note that acb->bh can be NULL in case where the aio was cancelled */
acb->bh = qemu_bh_new(rbd_aio_bh_cb, acb);
qemu_bh_schedule(acb->bh);
+
done:
g_free(rcb);
}
@@ -573,7 +574,10 @@ static void qemu_rbd_close(BlockDriverState *bs)
static void qemu_rbd_aio_cancel(BlockDriverAIOCB *blockacb)
{
RBDAIOCB *acb = (RBDAIOCB *) blockacb;
- acb->cancelled = 1;
+
+ while (acb->status == -EINPROGRESS) {
+ qemu_aio_wait();
+ }
}
static AIOPool rbd_aio_pool = {
@@ -642,10 +646,11 @@ static void rbd_aio_bh_cb(void *opaque)
qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
}
qemu_vfree(acb->bounce);
- acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));
qemu_bh_delete(acb->bh);
acb->bh = NULL;
+ acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));
+
qemu_aio_release(acb);
}
@@ -689,8 +694,8 @@ static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs,
acb->ret = 0;
acb->error = 0;
acb->s = s;
- acb->cancelled = 0;
acb->bh = NULL;
+ acb->status = -EINPROGRESS;
if (cmd == RBD_AIO_WRITE) {
qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
--
1.7.10.4
next prev parent reply other threads:[~2012-11-19 21:06 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-19 20:39 (no subject) Stefan Priebe
2012-11-19 20:39 ` [Qemu-devel] " Stefan Priebe
2012-11-19 20:39 ` Stefan Priebe [this message]
2012-11-21 8:56 ` [Qemu-devel] [PATCH] rbd block driver fix race between aio completition and aio cancel Josh Durgin
2012-11-21 9:07 ` Stefan Hajnoczi
2012-11-21 9:19 ` Stefan Priebe - Profihost AG
2012-11-21 15:34 ` Paolo Bonzini
2012-11-22 10:01 ` Stefan Priebe - Profihost AG
2012-11-19 20:43 ` Stefan Priebe
2012-11-22 10:00 [Qemu-devel] " Stefan Priebe
2012-11-24 19:54 ` Blue Swirl
2012-11-24 19:54 ` Blue Swirl
2012-11-24 20:21 ` Stefan Priebe
2012-11-24 20:21 ` Stefan Priebe
2012-11-27 22:42 ` Josh Durgin
2012-11-29 15:24 ` Paolo Bonzini
2012-11-29 13:58 ` Stefan Hajnoczi
2012-11-29 14:32 ` Stefan Priebe - Profihost AG
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