block/io: bdrv_pad_request(): support qemu_iovec_init_extended failure

Make bdrv_pad_request() honest: return error if
qemu_iovec_init_extended() failed.

Update also bdrv_padding_destroy() to clean the structure for safety.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-6-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 21:39:23 +03:00 committed by Eric Blake
parent f0deecff82
commit 98ca45494f

View File

@ -1665,6 +1665,7 @@ static void bdrv_padding_destroy(BdrvRequestPadding *pad)
qemu_vfree(pad->buf);
qemu_iovec_destroy(&pad->local_qiov);
}
memset(pad, 0, sizeof(*pad));
}
/*
@ -1674,33 +1675,42 @@ static void bdrv_padding_destroy(BdrvRequestPadding *pad)
* read of padding, bdrv_padding_rmw_read() should be called separately if
* needed.
*
* All parameters except @bs are in-out: they represent original request at
* function call and padded (if padding needed) at function finish.
*
* Function always succeeds.
* Request parameters (@qiov, &qiov_offset, &offset, &bytes) are in-out:
* - on function start they represent original request
* - on failure or when padding is not needed they are unchanged
* - on success when padding is needed they represent padded request
*/
static bool bdrv_pad_request(BlockDriverState *bs,
static int bdrv_pad_request(BlockDriverState *bs,
QEMUIOVector **qiov, size_t *qiov_offset,
int64_t *offset, unsigned int *bytes,
BdrvRequestPadding *pad)
BdrvRequestPadding *pad, bool *padded)
{
int ret;
if (!bdrv_init_padding(bs, *offset, *bytes, pad)) {
return false;
if (padded) {
*padded = false;
}
return 0;
}
ret = qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head,
*qiov, *qiov_offset, *bytes,
pad->buf + pad->buf_len - pad->tail,
pad->tail);
assert(ret == 0);
if (ret < 0) {
bdrv_padding_destroy(pad);
return ret;
}
*bytes += pad->head + pad->tail;
*offset -= pad->head;
*qiov = &pad->local_qiov;
*qiov_offset = 0;
if (padded) {
*padded = true;
}
return true;
return 0;
}
int coroutine_fn bdrv_co_preadv(BdrvChild *child,
@ -1750,7 +1760,11 @@ int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
flags |= BDRV_REQ_COPY_ON_READ;
}
bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad);
ret = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad,
NULL);
if (ret < 0) {
return ret;
}
tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);
ret = bdrv_aligned_preadv(child, &req, offset, bytes,
@ -2173,8 +2187,11 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
* bdrv_co_do_zero_pwritev() does aligning by itself, so, we do
* alignment only if there is no ZERO flag.
*/
padded = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes,
&pad);
ret = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad,
&padded);
if (ret < 0) {
return ret;
}
}
bdrv_inc_in_flight(bs);