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block: Tighter assertions on bdrv_aligned_pwritev()

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For symmetry with bdrv_aligned_preadv(), assert that the caller
really has aligned things properly. This requires adding an align
parameter, which is used now only in the new asserts, but will
come in handy in a later patch that adds auto-fragmentation to the
max transfer size, since that value need not always be a multiple
of the alignment, and therefore must be rounded down.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2016-06-23 16:37:05 -06:00 committed by Kevin Wolf
parent cfef6a45c7
commit cff86b38ac
1 changed files with 8 additions and 5 deletions
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13
block/io.c
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@ -1254,7 +1254,7 @@ fail:
*/ */
static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
QEMUIOVector *qiov, int flags) int64_t align, QEMUIOVector *qiov, int flags)
{ {
BlockDriver *drv = bs->drv; BlockDriver *drv = bs->drv;
bool waited; bool waited;
@ -1263,6 +1263,9 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
int64_t start_sector = offset >> BDRV_SECTOR_BITS; int64_t start_sector = offset >> BDRV_SECTOR_BITS;
int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE); int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
assert(is_power_of_2(align));
assert((offset & (align - 1)) == 0);
assert((bytes & (align - 1)) == 0);
assert(!qiov || bytes == qiov->size); assert(!qiov || bytes == qiov->size);
assert((bs->open_flags & BDRV_O_NO_IO) == 0); assert((bs->open_flags & BDRV_O_NO_IO) == 0);
assert(!(flags & ~BDRV_REQ_MASK)); assert(!(flags & ~BDRV_REQ_MASK));
@ -1349,7 +1352,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs,
memset(buf + head_padding_bytes, 0, zero_bytes); memset(buf + head_padding_bytes, 0, zero_bytes);
ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align, ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align,
&local_qiov, align, &local_qiov,
flags & ~BDRV_REQ_ZERO_WRITE); flags & ~BDRV_REQ_ZERO_WRITE);
if (ret < 0) { if (ret < 0) {
goto fail; goto fail;
@ -1362,7 +1365,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs,
if (bytes >= align) { if (bytes >= align) {
/* Write the aligned part in the middle. */ /* Write the aligned part in the middle. */
uint64_t aligned_bytes = bytes & ~(align - 1); uint64_t aligned_bytes = bytes & ~(align - 1);
ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes, ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes, align,
NULL, flags); NULL, flags);
if (ret < 0) { if (ret < 0) {
goto fail; goto fail;
@ -1386,7 +1389,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs,
bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
memset(buf, 0, bytes); memset(buf, 0, bytes);
ret = bdrv_aligned_pwritev(bs, req, offset, align, ret = bdrv_aligned_pwritev(bs, req, offset, align, align,
&local_qiov, flags & ~BDRV_REQ_ZERO_WRITE); &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE);
} }
fail: fail:
@ -1511,7 +1514,7 @@ int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs,
bytes = ROUND_UP(bytes, align); bytes = ROUND_UP(bytes, align);
} }
ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, align,
use_local_qiov ? &local_qiov : qiov, use_local_qiov ? &local_qiov : qiov,
flags); flags);