block: Introduce bdrv_aligned_pwritev()
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 <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
diff --git a/block.c b/block.c
index fa4feb0..d9c472b 100644
--- a/block.c
+++ b/block.c
@@ -3144,34 +3144,20 @@
}
/*
- * 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;
- }
+ int64_t sector_num = offset >> BDRV_SECTOR_BITS;
+ unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
- 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);
- }
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
@@ -3203,6 +3189,40 @@
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)
{
