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Re: [Qemu-block] [Qemu-devel] [PATCH v4 03/23] block: Make bdrv_round_to
From: |
John Snow |
Subject: |
Re: [Qemu-block] [Qemu-devel] [PATCH v4 03/23] block: Make bdrv_round_to_clusters() signature more useful |
Date: |
Tue, 26 Sep 2017 14:51:38 -0400 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 |
On 09/13/2017 12:03 PM, Eric Blake wrote:
> In the process of converting sector-based interfaces to bytes,
> I'm finding it easier to represent a byte count as a 64-bit
> integer at the block layer (even if we are internally capped
> by SIZE_MAX or even INT_MAX for individual transactions, it's
> still nicer to not have to worry about truncation/overflow
> issues on as many variables). Update the signature of
> bdrv_round_to_clusters() to uniformly use int64_t, matching
> the signature already chosen for bdrv_is_allocated and the
> fact that off_t is also a signed type, then adjust clients
> according to the required fallout.
>
> Signed-off-by: Eric Blake <address@hidden>
> Reviewed-by: Fam Zheng <address@hidden>
>
> ---
> v4: only context changes
> v3: no change
> v2: fix commit message [John], rebase to earlier changes, including
> mirror_clip_bytes() signature update
> ---
> include/block/block.h | 4 ++--
> block/io.c | 7 ++++---
> block/mirror.c | 7 +++----
> block/trace-events | 2 +-
> 4 files changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/include/block/block.h b/include/block/block.h
> index 2ad18775af..bb3b95d491 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -475,9 +475,9 @@ int bdrv_get_flags(BlockDriverState *bs);
> int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
> ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
> void bdrv_round_to_clusters(BlockDriverState *bs,
> - int64_t offset, unsigned int bytes,
> + int64_t offset, int64_t bytes,
> int64_t *cluster_offset,
> - unsigned int *cluster_bytes);
> + int64_t *cluster_bytes);
>
> const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
> void bdrv_get_backing_filename(BlockDriverState *bs,
> diff --git a/block/io.c b/block/io.c
> index 6509c804d4..b362b46e3d 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -446,9 +446,9 @@ static void mark_request_serialising(BdrvTrackedRequest
> *req, uint64_t align)
> * Round a region to cluster boundaries
> */
> void bdrv_round_to_clusters(BlockDriverState *bs,
> - int64_t offset, unsigned int bytes,
> + int64_t offset, int64_t bytes,
> int64_t *cluster_offset,
> - unsigned int *cluster_bytes)
> + int64_t *cluster_bytes)
> {
> BlockDriverInfo bdi;
>
> @@ -946,7 +946,7 @@ static int coroutine_fn
> bdrv_co_do_copy_on_readv(BdrvChild *child,
> struct iovec iov;
> QEMUIOVector bounce_qiov;
> int64_t cluster_offset;
> - unsigned int cluster_bytes;
> + int64_t cluster_bytes;
> size_t skip_bytes;
> int ret;
>
> @@ -967,6 +967,7 @@ static int coroutine_fn
> bdrv_co_do_copy_on_readv(BdrvChild *child,
> trace_bdrv_co_do_copy_on_readv(bs, offset, bytes,
> cluster_offset, cluster_bytes);
>
> + assert(cluster_bytes < SIZE_MAX);
later in this function, is there any real or imagined risk of
cluster_bytes exceeding INT_MAX when it's passed to
bdrv_co_do_pwrite_zeroes?
> iov.iov_len = cluster_bytes;
> iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
> if (bounce_buffer == NULL) {
> diff --git a/block/mirror.c b/block/mirror.c
> index 032cfe91fa..67f45cec4e 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -190,10 +190,9 @@ static int mirror_cow_align(MirrorBlockJob *s, int64_t
> *offset,
> bool need_cow;
> int ret = 0;
> int64_t align_offset = *offset;
> - unsigned int align_bytes = *bytes;
> + int64_t align_bytes = *bytes;
> int max_bytes = s->granularity * s->max_iov;
>
> - assert(*bytes < INT_MAX);
> need_cow = !test_bit(*offset / s->granularity, s->cow_bitmap);
> need_cow |= !test_bit((*offset + *bytes - 1) / s->granularity,
> s->cow_bitmap);
> @@ -388,7 +387,7 @@ static uint64_t coroutine_fn
> mirror_iteration(MirrorBlockJob *s)
> while (nb_chunks > 0 && offset < s->bdev_length) {
> int64_t ret;
> int io_sectors;
> - unsigned int io_bytes;
> + int64_t io_bytes;
> int64_t io_bytes_acct;
> enum MirrorMethod {
> MIRROR_METHOD_COPY,
> @@ -413,7 +412,7 @@ static uint64_t coroutine_fn
> mirror_iteration(MirrorBlockJob *s)
> io_bytes = s->granularity;
> } else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) {
> int64_t target_offset;
> - unsigned int target_bytes;
> + int64_t target_bytes;
> bdrv_round_to_clusters(blk_bs(s->target), offset, io_bytes,
> &target_offset, &target_bytes);
> if (target_offset == offset &&
> diff --git a/block/trace-events b/block/trace-events
> index 25dd5a3026..4c6586f156 100644
> --- a/block/trace-events
> +++ b/block/trace-events
> @@ -12,7 +12,7 @@ blk_co_pwritev(void *blk, void *bs, int64_t offset,
> unsigned int bytes, int flag
> bdrv_co_preadv(void *bs, int64_t offset, int64_t nbytes, unsigned int flags)
> "bs %p offset %"PRId64" nbytes %"PRId64" flags 0x%x"
> bdrv_co_pwritev(void *bs, int64_t offset, int64_t nbytes, unsigned int
> flags) "bs %p offset %"PRId64" nbytes %"PRId64" flags 0x%x"
> bdrv_co_pwrite_zeroes(void *bs, int64_t offset, int count, int flags) "bs %p
> offset %"PRId64" count %d flags 0x%x"
> -bdrv_co_do_copy_on_readv(void *bs, int64_t offset, unsigned int bytes,
> int64_t cluster_offset, unsigned int cluster_bytes) "bs %p offset %"PRId64"
> bytes %u cluster_offset %"PRId64" cluster_bytes %u"
> +bdrv_co_do_copy_on_readv(void *bs, int64_t offset, int64_t bytes, int64_t
> cluster_offset, unsigned int cluster_bytes) "bs %p offset %"PRId64" bytes
> %"PRId64" cluster_offset %"PRId64" cluster_bytes %u"
>
> # block/stream.c
> stream_one_iteration(void *s, int64_t offset, uint64_t bytes, int
> is_allocated) "s %p offset %" PRId64 " bytes %" PRIu64 " is_allocated %d"
>
Everything else looks obviously correct to me.
[Qemu-block] [PATCH v4 05/23] block: Switch bdrv_make_zero() to byte-based, Eric Blake, 2017/09/13
[Qemu-block] [PATCH v4 04/23] qcow2: Switch is_zero_sectors() to byte-based, Eric Blake, 2017/09/13
[Qemu-block] [PATCH v4 06/23] qemu-img: Switch get_block_status() to byte-based, Eric Blake, 2017/09/13