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[Qemu-devel] [PULL 09/17] mirror: Do zero write on target if sectors not
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL 09/17] mirror: Do zero write on target if sectors not allocated |
Date: |
Thu, 2 Jul 2015 10:19:41 +0100 |
From: Fam Zheng <address@hidden>
If guest discards a source cluster, mirroring with bdrv_aio_readv is overkill.
Some protocols do zero upon discard, where it's best to use
bdrv_aio_write_zeroes, otherwise, bdrv_aio_discard will be enough.
Signed-off-by: Fam Zheng <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
block/mirror.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 4be06a5..8888cea 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -165,6 +165,8 @@ static uint64_t coroutine_fn
mirror_iteration(MirrorBlockJob *s)
int64_t end, sector_num, next_chunk, next_sector, hbitmap_next_sector;
uint64_t delay_ns = 0;
MirrorOp *op;
+ int pnum;
+ int64_t ret;
s->sector_num = hbitmap_iter_next(&s->hbi);
if (s->sector_num < 0) {
@@ -291,8 +293,22 @@ static uint64_t coroutine_fn
mirror_iteration(MirrorBlockJob *s)
s->in_flight++;
s->sectors_in_flight += nb_sectors;
trace_mirror_one_iteration(s, sector_num, nb_sectors);
- bdrv_aio_readv(source, sector_num, &op->qiov, nb_sectors,
- mirror_read_complete, op);
+
+ ret = bdrv_get_block_status_above(source, NULL, sector_num,
+ nb_sectors, &pnum);
+ if (ret < 0 || pnum < nb_sectors ||
+ (ret & BDRV_BLOCK_DATA && !(ret & BDRV_BLOCK_ZERO))) {
+ bdrv_aio_readv(source, sector_num, &op->qiov, nb_sectors,
+ mirror_read_complete, op);
+ } else if (ret & BDRV_BLOCK_ZERO) {
+ bdrv_aio_write_zeroes(s->target, sector_num, op->nb_sectors,
+ s->unmap ? BDRV_REQ_MAY_UNMAP : 0,
+ mirror_write_complete, op);
+ } else {
+ assert(!(ret & BDRV_BLOCK_DATA));
+ bdrv_aio_discard(s->target, sector_num, op->nb_sectors,
+ mirror_write_complete, op);
+ }
return delay_ns;
}
--
2.4.3
- [Qemu-devel] [PULL 00/17] Block patches, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 01/17] block/iscsi: add support for request timeouts, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 02/17] qcow2: Handle EAGAIN returned from update_refcount, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 03/17] qapi: Rename 'dirty-bitmap' mode to 'incremental', Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 04/17] blockdev: no need to drain+flush in hmp_drive_del, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 05/17] timer: Move NANOSECONDS_PER_SECONDS to timer.h, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 06/17] timer: Use a single definition of NSEC_PER_SEC for the whole codebase, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 07/17] block: Add bdrv_get_block_status_above, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 08/17] qmp: Add optional bool "unmap" to drive-mirror, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 09/17] mirror: Do zero write on target if sectors not allocated,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL 10/17] block: Fix dirty bitmap in bdrv_co_discard, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 11/17] block: Remove bdrv_reset_dirty, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 12/17] qemu-iotests: Make block job methods common, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 13/17] qemu-iotests: Add test case for mirror with unmap, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 14/17] iotests: Use event_wait in wait_ready, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 15/17] block/iscsi: restore compatiblity with libiscsi 1.9.0, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 16/17] block/nfs: limit maximum readahead size to 1MB, Stefan Hajnoczi, 2015/07/02
- [Qemu-devel] [PULL 17/17] block: remove redundant check before g_slist_find(), Stefan Hajnoczi, 2015/07/02
- Re: [Qemu-devel] [PULL 00/17] Block patches, Peter Maydell, 2015/07/02
- Re: [Qemu-devel] [PULL 00/17] Block patches, Peter Maydell, 2015/07/07