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block/io: support int64_t bytes in bdrv_co_p{read,write}v_part()

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We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, prepare bdrv_co_preadv_part() and bdrv_co_pwritev_part() and their
remaining dependencies now.

bdrv_pad_request() is updated simultaneously, as pointer to bytes passed
to it both from bdrv_co_pwritev_part() and bdrv_co_preadv_part().

So, all callers of bdrv_pad_request() are updated to pass 64bit bytes.
bdrv_pad_request() is already good for 64bit requests, add
corresponding assertion.

Look at bdrv_co_preadv_part() and bdrv_co_pwritev_part().
Type is widening, so callers are safe. Let's look inside the functions.

In bdrv_co_preadv_part() and bdrv_aligned_pwritev() we only pass bytes
to other already int64_t interfaces (and some obviously safe
calculations), it's OK.

In bdrv_co_do_zero_pwritev() aligned_bytes may become large now, still
it's passed to bdrv_aligned_pwritev which supports int64_t bytes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-15-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2020-12-11 21:39:32 +03:00 • committed by Eric Blake
parent 8b0c5d7659
commit 37e9403ea8
3 changed files with 12 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

14
block/io.c
View file

@ -1725,11 +1725,13 @@ static void bdrv_padding_destroy(BdrvRequestPadding *pad)
*/
static int bdrv_pad_request(BlockDriverState *bs,
QEMUIOVector **qiov, size_t *qiov_offset,
int64_t *offset, unsigned int *bytes,
int64_t *offset, int64_t *bytes,
BdrvRequestPadding *pad, bool *padded)
{
int ret;
bdrv_check_qiov_request(*offset, *bytes, *qiov, *qiov_offset, &error_abort);
if (!bdrv_init_padding(bs, *offset, *bytes, pad)) {
if (padded) {
*padded = false;
@ -1764,7 +1766,7 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child,
}
int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
int64_t offset, unsigned int bytes,
int64_t offset, int64_t bytes,
QEMUIOVector *qiov, size_t qiov_offset,
BdrvRequestFlags flags)
{
@ -1773,7 +1775,7 @@ int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
BdrvRequestPadding pad;
int ret;
trace_bdrv_co_preadv(bs, offset, bytes, flags);
trace_bdrv_co_preadv_part(bs, offset, bytes, flags);
if (!bdrv_is_inserted(bs)) {
return -ENOMEDIUM;
@ -2117,7 +2119,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
int64_t offset,
unsigned int bytes,
int64_t bytes,
BdrvRequestFlags flags,
BdrvTrackedRequest *req)
{
@ -2191,7 +2193,7 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
}
int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
int64_t offset, unsigned int bytes, QEMUIOVector *qiov, size_t qiov_offset,
int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset,
BdrvRequestFlags flags)
{
BlockDriverState *bs = child->bs;
@ -2201,7 +2203,7 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
int ret;
bool padded = false;
trace_bdrv_co_pwritev(child->bs, offset, bytes, flags);
trace_bdrv_co_pwritev_part(child->bs, offset, bytes, flags);
if (!bdrv_is_inserted(bs)) {
return -ENOMEDIUM;