[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 02/14] block: simplify failure handling for bdrv_aio
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 02/14] block: simplify failure handling for bdrv_aio_multiwrite |
Date: |
Thu, 15 Dec 2011 15:09:17 +0100 |
From: Paolo Bonzini <address@hidden>
Now that early failure of bdrv_aio_writev is not possible anymore,
mcb->num_requests can be set before the loop starts.
Signed-off-by: Paolo Bonzini <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 28 ++--------------------------
1 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/block.c b/block.c
index 434c13d..16a4c42 100644
--- a/block.c
+++ b/block.c
@@ -2842,37 +2842,13 @@ int bdrv_aio_multiwrite(BlockDriverState *bs,
BlockRequest *reqs, int num_reqs)
trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
- /*
- * Run the aio requests. As soon as one request can't be submitted
- * successfully, fail all requests that are not yet submitted (we must
- * return failure for all requests anyway)
- *
- * num_requests cannot be set to the right value immediately: If
- * bdrv_aio_writev fails for some request, num_requests would be too high
- * and therefore multiwrite_cb() would never recognize the multiwrite
- * request as completed. We also cannot use the loop variable i to set it
- * when the first request fails because the callback may already have been
- * called for previously submitted requests. Thus, num_requests must be
- * incremented for each request that is submitted.
- *
- * The problem that callbacks may be called early also means that we need
- * to take care that num_requests doesn't become 0 before all requests are
- * submitted - multiwrite_cb() would consider the multiwrite request
- * completed. A dummy request that is "completed" by a manual call to
- * multiwrite_cb() takes care of this.
- */
- mcb->num_requests = 1;
-
- // Run the aio requests
+ /* Run the aio requests. */
+ mcb->num_requests = num_reqs;
for (i = 0; i < num_reqs; i++) {
- mcb->num_requests++;
bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
reqs[i].nb_sectors, multiwrite_cb, mcb);
}
- /* Complete the dummy request */
- multiwrite_cb(mcb, 0);
-
return 0;
}
--
1.7.6.4
- [Qemu-devel] [PULL 00/14] Block patches, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 01/14] block: bdrv_aio_* do not return NULL, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 02/14] block: simplify failure handling for bdrv_aio_multiwrite,
Kevin Wolf <=
- [Qemu-devel] [PATCH 06/14] block: avoid useless checks on acb->bh, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 03/14] block: qemu_aio_get does not return NULL, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 07/14] block/qcow2.c: call qcow2_free_snapshots in the function of qcow2_close, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 04/14] dma: the passed io_func does not return NULL, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 08/14] rbd: always set out parameter in qemu_rbd_snap_list, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 05/14] block: dma_bdrv_* does not return NULL, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 11/14] qcow2: Allow >4 GB VM state, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 09/14] qemu-img rebase: Fix for undersized backing files, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 13/14] block/cow: Return real error code, Kevin Wolf, 2011/12/15
- [Qemu-devel] [PATCH 14/14] qiov: prevent double free or use-after-free, Kevin Wolf, 2011/12/15