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author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2019-06-04 19:15:06 +0300 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2019-08-27 14:58:42 +0100 |
commit | ac850bf099f8a356788d487c5205345dfd755fca (patch) | |
tree | 4a28c7ae9b6ff9c90ad8231885eabc7a42df49f6 /block/io.c | |
parent | 7a3f542fbdfd799be4fa6f8b96dc8c1e6933fce4 (diff) | |
download | qemu-ac850bf099f8a356788d487c5205345dfd755fca.zip qemu-ac850bf099f8a356788d487c5205345dfd755fca.tar.gz qemu-ac850bf099f8a356788d487c5205345dfd755fca.tar.bz2 |
block: define .*_part io handlers in BlockDriver
Add handlers supporting qiov_offset parameter:
bdrv_co_preadv_part
bdrv_co_pwritev_part
bdrv_co_pwritev_compressed_part
This is used to reduce need of defining local_qiovs and hd_qiovs in all
corners of block layer code. The following patches will increase usage
of this new API part by part.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-5-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-5-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/io.c')
-rw-r--r-- | block/io.c | 96 |
1 files changed, 77 insertions, 19 deletions
@@ -146,7 +146,8 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) /* Default alignment based on whether driver has byte interface */ bs->bl.request_alignment = (drv->bdrv_co_preadv || - drv->bdrv_aio_preadv) ? 1 : 512; + drv->bdrv_aio_preadv || + drv->bdrv_co_preadv_part) ? 1 : 512; /* Take some limits from the children as a default */ if (bs->file) { @@ -1044,11 +1045,14 @@ static void bdrv_co_io_em_complete(void *opaque, int ret) static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, - QEMUIOVector *qiov, int flags) + QEMUIOVector *qiov, + size_t qiov_offset, int flags) { BlockDriver *drv = bs->drv; int64_t sector_num; unsigned int nb_sectors; + QEMUIOVector local_qiov; + int ret; assert(!(flags & ~BDRV_REQ_MASK)); assert(!(flags & BDRV_REQ_NO_FALLBACK)); @@ -1057,8 +1061,19 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs, return -ENOMEDIUM; } + if (drv->bdrv_co_preadv_part) { + return drv->bdrv_co_preadv_part(bs, offset, bytes, qiov, qiov_offset, + flags); + } + + if (qiov_offset > 0 || bytes != qiov->size) { + qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes); + qiov = &local_qiov; + } + if (drv->bdrv_co_preadv) { - return drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags); + ret = drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags); + goto out; } if (drv->bdrv_aio_preadv) { @@ -1070,10 +1085,12 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs, acb = drv->bdrv_aio_preadv(bs, offset, bytes, qiov, flags, bdrv_co_io_em_complete, &co); if (acb == NULL) { - return -EIO; + ret = -EIO; + goto out; } else { qemu_coroutine_yield(); - return co.ret; + ret = co.ret; + goto out; } } @@ -1085,16 +1102,25 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs, assert(bytes <= BDRV_REQUEST_MAX_BYTES); assert(drv->bdrv_co_readv); - return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); + ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); + +out: + if (qiov == &local_qiov) { + qemu_iovec_destroy(&local_qiov); + } + + return ret; } static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, - QEMUIOVector *qiov, int flags) + QEMUIOVector *qiov, + size_t qiov_offset, int flags) { BlockDriver *drv = bs->drv; int64_t sector_num; unsigned int nb_sectors; + QEMUIOVector local_qiov; int ret; assert(!(flags & ~BDRV_REQ_MASK)); @@ -1104,6 +1130,18 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs, return -ENOMEDIUM; } + if (drv->bdrv_co_pwritev_part) { + ret = drv->bdrv_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, + flags & bs->supported_write_flags); + flags &= ~bs->supported_write_flags; + goto emulate_flags; + } + + if (qiov_offset > 0 || bytes != qiov->size) { + qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes); + qiov = &local_qiov; + } + if (drv->bdrv_co_pwritev) { ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov, flags & bs->supported_write_flags); @@ -1147,24 +1185,44 @@ emulate_flags: ret = bdrv_co_flush(bs); } + if (qiov == &local_qiov) { + qemu_iovec_destroy(&local_qiov); + } + return ret; } static int coroutine_fn bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset, - uint64_t bytes, QEMUIOVector *qiov) + uint64_t bytes, QEMUIOVector *qiov, + size_t qiov_offset) { BlockDriver *drv = bs->drv; + QEMUIOVector local_qiov; + int ret; if (!drv) { return -ENOMEDIUM; } - if (!drv->bdrv_co_pwritev_compressed) { + if (!block_driver_can_compress(drv)) { return -ENOTSUP; } - return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov); + if (drv->bdrv_co_pwritev_compressed_part) { + return drv->bdrv_co_pwritev_compressed_part(bs, offset, bytes, + qiov, qiov_offset); + } + + if (qiov_offset == 0) { + return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov); + } + + qemu_iovec_init_slice(&local_qiov, qiov, qiov_offset, bytes); + ret = drv->bdrv_co_pwritev_compressed(bs, offset, bytes, &local_qiov); + qemu_iovec_destroy(&local_qiov); + + return ret; } static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, @@ -1249,7 +1307,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum); ret = bdrv_driver_preadv(bs, cluster_offset, pnum, - &local_qiov, 0); + &local_qiov, 0, 0); if (ret < 0) { goto err; } @@ -1267,7 +1325,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, * necessary to flush even in cache=writethrough mode. */ ret = bdrv_driver_pwritev(bs, cluster_offset, pnum, - &local_qiov, + &local_qiov, 0, BDRV_REQ_WRITE_UNCHANGED); } @@ -1289,7 +1347,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, qemu_iovec_init(&local_qiov, qiov->niov); qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes); ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size, - &local_qiov, 0); + &local_qiov, 0, 0); qemu_iovec_destroy(&local_qiov); if (ret < 0) { goto err; @@ -1380,7 +1438,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align); if (bytes <= max_bytes && bytes <= max_transfer) { - ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0); + ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0, 0); goto out; } @@ -1396,7 +1454,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num); ret = bdrv_driver_preadv(bs, offset + bytes - bytes_remaining, - num, &local_qiov, 0); + num, &local_qiov, 0, 0); max_bytes -= num; qemu_iovec_destroy(&local_qiov); } else { @@ -1701,7 +1759,7 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, } qemu_iovec_init_buf(&qiov, buf, num); - ret = bdrv_driver_pwritev(bs, offset, num, &qiov, write_flags); + ret = bdrv_driver_pwritev(bs, offset, num, &qiov, 0, write_flags); /* Keep bounce buffer around if it is big enough for all * all future requests. @@ -1857,10 +1915,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child, bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO); ret = bdrv_co_do_pwrite_zeroes(bs, offset, bytes, flags); } else if (flags & BDRV_REQ_WRITE_COMPRESSED) { - ret = bdrv_driver_pwritev_compressed(bs, offset, bytes, qiov); + ret = bdrv_driver_pwritev_compressed(bs, offset, bytes, qiov, 0); } else if (bytes <= max_transfer) { bdrv_debug_event(bs, BLKDBG_PWRITEV); - ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, flags); + ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, 0, flags); } else { bdrv_debug_event(bs, BLKDBG_PWRITEV); while (bytes_remaining) { @@ -1879,7 +1937,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child, qemu_iovec_concat(&local_qiov, qiov, bytes - bytes_remaining, num); ret = bdrv_driver_pwritev(bs, offset + bytes - bytes_remaining, - num, &local_qiov, local_flags); + num, &local_qiov, 0, local_flags); qemu_iovec_destroy(&local_qiov); if (ret < 0) { break; |