Re: [Qemu-devel] [PATCH v3 11/29] block: Introduce bdrv_aligned_pwritev()
Le Friday 17 Jan 2014 à 15:15:01 (+0100), Kevin Wolf a écrit : 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 kw...@redhat.com Reviewed-by: Max Reitz mre...@redhat.com --- block.c | 62 +- 1 file changed, 41 insertions(+), 21 deletions(-) diff --git a/block.c b/block.c index f378a10..70b72f0 100644 --- a/block.c +++ b/block.c @@ -2964,34 +2964,20 @@ 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); @@ -3023,6 +3009,40 @@ 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 Reviewed-by: Benoit Canet ben...@irqsave.net
[Qemu-devel] [PATCH v3 11/29] 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 kw...@redhat.com Reviewed-by: Max Reitz mre...@redhat.com --- block.c | 62 +- 1 file changed, 41 insertions(+), 21 deletions(-) diff --git a/block.c b/block.c index f378a10..70b72f0 100644 --- a/block.c +++ b/block.c @@ -2964,34 +2964,20 @@ 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); @@ -3023,6 +3009,40 @@ 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