mirror of
https://gitlab.com/qemu-project/qemu
synced 2024-09-06 18:05:37 +00:00
block/parallels: switch to bdrv_read
Switch the .bdrv_read method implementation from using bdrv_pread() to bdrv_read() on the underlying file, since the latter is subject to i/o throttling while the former is not. Besides, since bdrv_read() operates in sectors rather than bytes, adjust the helper functions to do so too. Signed-off-by: Roman Kagan <rkagan@parallels.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Denis V. Lunev <den@openvz.org> Message-id: 1430207220-24458-4-git-send-email-den@openvz.org CC: Kevin Wolf <kwolf@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
parent
0789890467
commit
2944256997
|
@ -146,9 +146,8 @@ fail:
|
|||
return ret;
|
||||
}
|
||||
|
||||
static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
|
||||
static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
|
||||
{
|
||||
BDRVParallelsState *s = bs->opaque;
|
||||
uint32_t index, offset;
|
||||
|
||||
index = sector_num / s->tracks;
|
||||
|
@ -157,24 +156,27 @@ static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
|
|||
/* not allocated */
|
||||
if ((index >= s->catalog_size) || (s->catalog_bitmap[index] == 0))
|
||||
return -1;
|
||||
return
|
||||
((uint64_t)s->catalog_bitmap[index] * s->off_multiplier + offset) * 512;
|
||||
return (uint64_t)s->catalog_bitmap[index] * s->off_multiplier + offset;
|
||||
}
|
||||
|
||||
static int parallels_read(BlockDriverState *bs, int64_t sector_num,
|
||||
uint8_t *buf, int nb_sectors)
|
||||
{
|
||||
BDRVParallelsState *s = bs->opaque;
|
||||
|
||||
while (nb_sectors > 0) {
|
||||
int64_t position = seek_to_sector(bs, sector_num);
|
||||
int64_t position = seek_to_sector(s, sector_num);
|
||||
if (position >= 0) {
|
||||
if (bdrv_pread(bs->file, position, buf, 512) != 512)
|
||||
return -1;
|
||||
int ret = bdrv_read(bs->file, position, buf, 1);
|
||||
if (ret < 0) {
|
||||
return ret;
|
||||
}
|
||||
} else {
|
||||
memset(buf, 0, 512);
|
||||
memset(buf, 0, BDRV_SECTOR_SIZE);
|
||||
}
|
||||
nb_sectors--;
|
||||
sector_num++;
|
||||
buf += 512;
|
||||
buf += BDRV_SECTOR_SIZE;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue