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[PATCH v4 04/16] block/io: refactor bdrv_pad_request(): move bdrv_pad_re
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[PATCH v4 04/16] block/io: refactor bdrv_pad_request(): move bdrv_pad_request() up |
Date: |
Fri, 11 Dec 2020 21:39:22 +0300 |
Prepare to the following patch when bdrv_pad_request() will be able to
fail. Update the comments.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
block/io.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/block/io.c b/block/io.c
index d9bc67f1b0..dcfab267f8 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2107,6 +2107,7 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
uint64_t align = bs->bl.request_alignment;
BdrvRequestPadding pad;
int ret;
+ bool padded = false;
trace_bdrv_co_pwritev(child->bs, offset, bytes, flags);
@@ -2138,20 +2139,32 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
return 0;
}
+ if (!(flags & BDRV_REQ_ZERO_WRITE)) {
+ /*
+ * Pad request for following read-modify-write cycle.
+ * bdrv_co_do_zero_pwritev() does aligning by itself, so, we do
+ * alignment only if there is no ZERO flag.
+ */
+ padded = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes,
+ &pad);
+ }
+
bdrv_inc_in_flight(bs);
- /*
- * Align write if necessary by performing a read-modify-write cycle.
- * Pad qiov with the read parts and be sure to have a tracked request not
- * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
- */
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE);
if (flags & BDRV_REQ_ZERO_WRITE) {
+ assert(!padded);
ret = bdrv_co_do_zero_pwritev(child, offset, bytes, flags, &req);
goto out;
}
- if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) {
+ if (padded) {
+ /*
+ * Request was unaligned to request_alignment and therefore padded.
+ * We are going to do read-modify-write. User is not prepared to
widened
+ * request intersections with other requests, so we serialize the
+ * request.
+ */
bdrv_mark_request_serialising(&req, align);
bdrv_padding_rmw_read(child, &req, &pad, false);
}
--
2.25.4
- [PATCH v4 00/16] 64bit block-layer: part I, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 01/16] block: refactor bdrv_check_request: add errp, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 04/16] block/io: refactor bdrv_pad_request(): move bdrv_pad_request() up,
Vladimir Sementsov-Ogievskiy <=
- [PATCH v4 02/16] util/iov: make qemu_iovec_init_extended() honest, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 05/16] block/io: bdrv_pad_request(): support qemu_iovec_init_extended failure, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 03/16] block: fix theoretical overflow in bdrv_init_padding(), Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 06/16] block/throttle-groups: throttle_group_co_io_limits_intercept(): 64bit bytes, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 15/16] block/io: support int64_t bytes in read/write wrappers, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 07/16] block/io: improve bdrv_check_request: check qiov too, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 08/16] block: use int64_t as bytes type in tracked requests, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 16/16] block/io: use int64_t bytes in copy_range, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 09/16] block/io: use int64_t bytes in driver wrappers, Vladimir Sementsov-Ogievskiy, 2020/12/11
- [PATCH v4 11/16] block/io: support int64_t bytes in bdrv_aligned_pwritev(), Vladimir Sementsov-Ogievskiy, 2020/12/11