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authorEric Blake <eblake@redhat.com>2016-06-23 16:37:05 -0600
committerKevin Wolf <kwolf@redhat.com>2016-07-05 16:46:24 +0200
commitcff86b38aca34c9cc5c6f8846cc1c5b3d181c376 (patch)
treea46c1066dd8715dd3a809efb2bb61e6a78e9b68c /block
parentcfef6a45c7201c8219d819d792e5d99bbff32308 (diff)
downloadqemu-cff86b38aca34c9cc5c6f8846cc1c5b3d181c376.tar.gz
block: Tighter assertions on bdrv_aligned_pwritev()
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>
Diffstat (limited to 'block')
-rw-r--r--block/io.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/block/io.c b/block/io.c
index 7cf3645ade..b95e856cf9 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1254,7 +1254,7 @@ fail:
*/
static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
- QEMUIOVector *qiov, int flags)
+ int64_t align, QEMUIOVector *qiov, int flags)
{
BlockDriver *drv = bs->drv;
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 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((bs->open_flags & BDRV_O_NO_IO) == 0);
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);
ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align,
- &local_qiov,
+ align, &local_qiov,
flags & ~BDRV_REQ_ZERO_WRITE);
if (ret < 0) {
goto fail;
@@ -1362,7 +1365,7 @@ 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,
+ ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes, align,
NULL, flags);
if (ret < 0) {
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);
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);
}
fail:
@@ -1511,7 +1514,7 @@ int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs,
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,
flags);