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[Qemu-devel] [RFC PATCH 08/19] block: Introduce bdrv_aligned_pwritev()
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [RFC PATCH 08/19] block: Introduce bdrv_aligned_pwritev() |
Date: |
Fri, 6 Dec 2013 18:22:49 +0100 |
This separates the part of bdrv_co_do_writev() that needs to happen
before the request is modified to match the backend alignment, and a
part that needs to be executed afterwards and passes the request to the
BlockDriver.
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 62 +++++++++++++++++++++++++++++++++++++++++---------------------
1 file changed, 41 insertions(+), 21 deletions(-)
diff --git a/block.c b/block.c
index 5f11935..20ed857 100644
--- a/block.c
+++ b/block.c
@@ -2852,34 +2852,20 @@ static int coroutine_fn
bdrv_co_do_write_zeroes(BlockDriverState *bs,
}
/*
- * Handle a write request in coroutine context
+ * Forwards an already correctly aligned write request to the BlockDriver.
*/
-static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
- BdrvRequestFlags flags)
+static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
+ int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags)
{
BlockDriver *drv = bs->drv;
BdrvTrackedRequest req;
int ret;
- if (!bs->drv) {
- return -ENOMEDIUM;
- }
- if (bs->read_only) {
- return -EACCES;
- }
- if (bdrv_check_request(bs, sector_num, nb_sectors)) {
- return -EIO;
- }
-
- if (bs->copy_on_read_in_flight) {
- wait_for_overlapping_requests(bs, sector_num, nb_sectors);
- }
+ int64_t sector_num = offset >> BDRV_SECTOR_BITS;
+ unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
- /* throttling disk I/O */
- if (bs->io_limits_enabled) {
- bdrv_io_limits_intercept(bs, nb_sectors, true);
- }
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
@@ -2913,6 +2899,40 @@ static int coroutine_fn
bdrv_co_do_writev(BlockDriverState *bs,
return ret;
}
+/*
+ * Handle a write request in coroutine context
+ */
+static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ BdrvRequestFlags flags)
+{
+ int ret;
+
+ if (!bs->drv) {
+ return -ENOMEDIUM;
+ }
+ if (bs->read_only) {
+ return -EACCES;
+ }
+ if (bdrv_check_request(bs, sector_num, nb_sectors)) {
+ return -EIO;
+ }
+
+ if (bs->copy_on_read_in_flight) {
+ wait_for_overlapping_requests(bs, sector_num, nb_sectors);
+ }
+
+ /* throttling disk I/O */
+ if (bs->io_limits_enabled) {
+ bdrv_io_limits_intercept(bs, nb_sectors, true);
+ }
+
+ ret = bdrv_aligned_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
+
+ return ret;
+}
+
int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
--
1.8.1.4
- [Qemu-devel] [RFC PATCH 00/19] block: Support for 512b-on-4k emulation, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 01/19] qemu_memalign: Allow small alignments, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 02/19] block: Detect unaligned length in bdrv_qiov_is_aligned(), Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 03/19] block: Don't use guest sector size for qemu_blockalign(), Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 04/19] block: rename buffer_alignment to guest_block_size, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 05/19] raw: Probe required direct I/O alignment, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 06/19] block: Introduce bdrv_aligned_preadv(), Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 07/19] block: Introduce bdrv_co_do_preadv(), Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 08/19] block: Introduce bdrv_aligned_pwritev(),
Kevin Wolf <=
- [Qemu-devel] [RFC PATCH 09/19] block: write: Handle COR dependency after I/O throttling, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 10/19] block: Introduce bdrv_co_do_pwritev(), Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 11/19] block: Switch BdrvTrackedRequest to byte granularity, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 12/19] block: Allow waiting for overlapping requests between begin/end, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 13/19] block: Make zero-after-EOF work with larger alignment, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 14/19] block: Generalise and optimise COR serialisation, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 15/19] block: Make overlap range for serialisation dynamic, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 16/19] block: Align requests in bdrv_co_do_pwritev(), Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 17/19] block: Change coroutine wrapper to byte granularity, Kevin Wolf, 2013/12/06
- [Qemu-devel] [RFC PATCH 18/19] block: Make bdrv_pread() a bdrv_prwv_co() wrapper, Kevin Wolf, 2013/12/06