From 85c97ca7a10b93216bc95052e9dabe3a4bb8736a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 9 Feb 2017 15:58:43 +0100 Subject: [PATCH] block: Pass BdrvChild to bdrv_aligned_preadv/pwritev and copy-on-read This is where we want to check the permissions, so we need to have the BdrvChild around where they are stored. Signed-off-by: Kevin Wolf Acked-by: Fam Zheng Reviewed-by: Max Reitz --- block/io.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/block/io.c b/block/io.c index d5c45447fd..2592ca1bd4 100644 --- a/block/io.c +++ b/block/io.c @@ -925,9 +925,11 @@ bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset, return drv->bdrv_co_pwritev_compressed(bs, offset, bytes, qiov); } -static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, +static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, int64_t offset, unsigned int bytes, QEMUIOVector *qiov) { + BlockDriverState *bs = child->bs; + /* Perform I/O through a temporary buffer so that users who scribble over * their read buffer while the operation is in progress do not end up * modifying the image file. This is critical for zero-copy guest I/O @@ -1001,10 +1003,11 @@ err: * handles copy on read, zeroing after EOF, and fragmentation of large * reads; any other features must be implemented by the caller. */ -static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, +static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, int64_t align, QEMUIOVector *qiov, int flags) { + BlockDriverState *bs = child->bs; int64_t total_bytes, max_bytes; int ret = 0; uint64_t bytes_remaining = bytes; @@ -1050,7 +1053,7 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, } if (!ret || pnum != nb_sectors) { - ret = bdrv_co_do_copy_on_readv(bs, offset, bytes, qiov); + ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov); goto out; } } @@ -1158,7 +1161,7 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child, } tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ); - ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align, + ret = bdrv_aligned_preadv(child, &req, offset, bytes, align, use_local_qiov ? &local_qiov : qiov, flags); tracked_request_end(&req); @@ -1306,10 +1309,11 @@ fail: * Forwards an already correctly aligned write request to the BlockDriver, * after possibly fragmenting it. */ -static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, +static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child, BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, int64_t align, QEMUIOVector *qiov, int flags) { + BlockDriverState *bs = child->bs; BlockDriver *drv = bs->drv; bool waited; int ret; @@ -1397,12 +1401,13 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, return ret; } -static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, +static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child, int64_t offset, unsigned int bytes, BdrvRequestFlags flags, BdrvTrackedRequest *req) { + BlockDriverState *bs = child->bs; uint8_t *buf = NULL; QEMUIOVector local_qiov; struct iovec iov; @@ -1430,7 +1435,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, mark_request_serialising(req, align); wait_serialising_requests(req); bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); - ret = bdrv_aligned_preadv(bs, req, offset & ~(align - 1), align, + ret = bdrv_aligned_preadv(child, req, offset & ~(align - 1), align, align, &local_qiov, 0); if (ret < 0) { goto fail; @@ -1438,7 +1443,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); memset(buf + head_padding_bytes, 0, zero_bytes); - ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align, + ret = bdrv_aligned_pwritev(child, req, offset & ~(align - 1), align, align, &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE); if (ret < 0) { @@ -1452,7 +1457,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, if (bytes >= align) { /* Write the aligned part in the middle. */ uint64_t aligned_bytes = bytes & ~(align - 1); - ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes, align, + ret = bdrv_aligned_pwritev(child, req, offset, aligned_bytes, align, NULL, flags); if (ret < 0) { goto fail; @@ -1468,7 +1473,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, mark_request_serialising(req, align); wait_serialising_requests(req); bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); - ret = bdrv_aligned_preadv(bs, req, offset, align, + ret = bdrv_aligned_preadv(child, req, offset, align, align, &local_qiov, 0); if (ret < 0) { goto fail; @@ -1476,7 +1481,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); memset(buf, 0, bytes); - ret = bdrv_aligned_pwritev(bs, req, offset, align, align, + ret = bdrv_aligned_pwritev(child, req, offset, align, align, &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE); } fail: @@ -1523,7 +1528,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child, tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE); if (!qiov) { - ret = bdrv_co_do_zero_pwritev(bs, offset, bytes, flags, &req); + ret = bdrv_co_do_zero_pwritev(child, offset, bytes, flags, &req); goto out; } @@ -1542,7 +1547,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child, qemu_iovec_init_external(&head_qiov, &head_iov, 1); bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD); - ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align, + ret = bdrv_aligned_preadv(child, &req, offset & ~(align - 1), align, align, &head_qiov, 0); if (ret < 0) { goto fail; @@ -1584,8 +1589,8 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child, qemu_iovec_init_external(&tail_qiov, &tail_iov, 1); bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL); - ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align, - align, &tail_qiov, 0); + ret = bdrv_aligned_preadv(child, &req, (offset + bytes) & ~(align - 1), + align, align, &tail_qiov, 0); if (ret < 0) { goto fail; } @@ -1603,7 +1608,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child, bytes = ROUND_UP(bytes, align); } - ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, align, + ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align, use_local_qiov ? &local_qiov : qiov, flags);