block: Switch bdrv_io_limits_intercept() to byte granularity

Request sizes used to be rounded down to the next sector boundary,
allowing to bypass the I/O limit. Now all requests are accounted for
with their exact byte size.

Reported-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2014-01-16 13:29:10 +01:00
parent 9e1cb96d9a
commit d5103588aa

13
block.c
View File

@ -192,7 +192,7 @@ void bdrv_io_limits_enable(BlockDriverState *bs)
* @is_write: is the IO a write
*/
static void bdrv_io_limits_intercept(BlockDriverState *bs,
int nb_sectors,
unsigned int bytes,
bool is_write)
{
/* does this io must wait */
@ -205,9 +205,8 @@ static void bdrv_io_limits_intercept(BlockDriverState *bs,
}
/* the IO will be executed, do the accounting */
throttle_account(&bs->throttle_state,
is_write,
nb_sectors * BDRV_SECTOR_SIZE);
throttle_account(&bs->throttle_state, is_write, bytes);
/* if the next request must wait -> do nothing */
if (throttle_schedule_timer(&bs->throttle_state, is_write)) {
@ -2968,8 +2967,7 @@ static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
/* throttling disk I/O */
if (bs->io_limits_enabled) {
/* TODO Switch to byte granularity */
bdrv_io_limits_intercept(bs, bytes >> BDRV_SECTOR_BITS, false);
bdrv_io_limits_intercept(bs, bytes, false);
}
/* Align read if necessary by padding qiov */
@ -3193,8 +3191,7 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
/* throttling disk I/O */
if (bs->io_limits_enabled) {
/* TODO Switch to byte granularity */
bdrv_io_limits_intercept(bs, bytes >> BDRV_SECTOR_BITS, true);
bdrv_io_limits_intercept(bs, bytes, true);
}
/*