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[Qemu-devel] [PATCH v2 3/7] block/io: handle alignment and max_transfer
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-devel] [PATCH v2 3/7] block/io: handle alignment and max_transfer for copy_range |
Date: |
Fri, 9 Aug 2019 18:32:03 +0300 |
copy_range ignores these limitations, let's improve it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/io.c | 48 ++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 40 insertions(+), 8 deletions(-)
diff --git a/block/io.c b/block/io.c
index 06305c6ea6..a5efb2200f 100644
--- a/block/io.c
+++ b/block/io.c
@@ -3005,11 +3005,24 @@ static int coroutine_fn bdrv_co_copy_range_internal(
{
BdrvTrackedRequest req;
int ret;
+ uint32_t align = MAX(src->bs->bl.request_alignment,
+ dst->bs->bl.request_alignment);
+ uint32_t max_transfer =
+ QEMU_ALIGN_DOWN(MIN_NON_ZERO(MIN_NON_ZERO(src->bs->bl.max_transfer,
+
dst->bs->bl.max_transfer),
+ INT_MAX), align);
/* TODO We can support BDRV_REQ_NO_FALLBACK here */
assert(!(read_flags & BDRV_REQ_NO_FALLBACK));
assert(!(write_flags & BDRV_REQ_NO_FALLBACK));
+ if (max_transfer == 0 && bytes > 0) {
+ /*
+ * For example, if source max_transfer is smaller than target
alignment.
+ */
+ return -ENOTSUP;
+ }
+
if (!dst || !dst->bs) {
return -ENOMEDIUM;
}
@@ -3031,7 +3044,10 @@ static int coroutine_fn bdrv_co_copy_range_internal(
if (!src->bs->drv->bdrv_co_copy_range_from
|| !dst->bs->drv->bdrv_co_copy_range_to
- || src->bs->encrypted || dst->bs->encrypted) {
+ || src->bs->encrypted || dst->bs->encrypted ||
+ !QEMU_IS_ALIGNED(src_offset, src->bs->bl.request_alignment) ||
+ !QEMU_IS_ALIGNED(dst_offset, dst->bs->bl.request_alignment) ||
+ !QEMU_IS_ALIGNED(bytes, align)) {
return -ENOTSUP;
}
@@ -3046,11 +3062,22 @@ static int coroutine_fn bdrv_co_copy_range_internal(
wait_serialising_requests(&req);
}
- ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,
- src, src_offset,
- dst, dst_offset,
- bytes,
- read_flags, write_flags);
+ while (bytes) {
+ int num = MIN(bytes, max_transfer);
+
+ ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,
+ src, src_offset,
+ dst, dst_offset,
+ num,
+ read_flags,
+ write_flags);
+ if (ret < 0) {
+ break;
+ }
+ bytes -= num;
+ src_offset += num;
+ dst_offset += num;
+ }
tracked_request_end(&req);
bdrv_dec_in_flight(src->bs);
@@ -3060,12 +3087,17 @@ static int coroutine_fn bdrv_co_copy_range_internal(
BDRV_TRACKED_WRITE);
ret = bdrv_co_write_req_prepare(dst, dst_offset, bytes, &req,
write_flags);
- if (!ret) {
+ while (!ret && bytes) {
+ int num = MIN(bytes, max_transfer);
+
ret = dst->bs->drv->bdrv_co_copy_range_to(dst->bs,
src, src_offset,
dst, dst_offset,
- bytes,
+ num,
read_flags, write_flags);
+ bytes -= num;
+ src_offset += num;
+ dst_offset += num;
}
bdrv_co_write_req_finish(dst, dst_offset, bytes, &req, ret);
tracked_request_end(&req);
--
2.18.0
[Qemu-devel] [PATCH v2 3/7] block/io: handle alignment and max_transfer for copy_range,
Vladimir Sementsov-Ogievskiy <=
[Qemu-devel] [PATCH v2 7/7] block/backup: merge duplicated logic into backup_do_cow, Vladimir Sementsov-Ogievskiy, 2019/08/09
[Qemu-devel] [PATCH v2 4/7] block/backup: drop handling of max_transfer for copy_range, Vladimir Sementsov-Ogievskiy, 2019/08/09
[Qemu-devel] [PATCH v2 2/7] block/backup: refactor write_flags, Vladimir Sementsov-Ogievskiy, 2019/08/09
Re: [Qemu-devel] [PATCH v2 0/7] backup improvements, Vladimir Sementsov-Ogievskiy, 2019/08/09