| Message ID | 20170412174920.8744-11-eblake@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 04/12/2017 01:49 PM, Eric Blake wrote: > Now that we have adjusted the majority of the calls this function > makes to be byte-based, it is easier to read the code if it makes > passes over the image using bytes rather than sectors. > > Signed-off-by: Eric Blake <eblake@redhat.com> > --- > block/mirror.c | 35 ++++++++++++++--------------------- > 1 file changed, 14 insertions(+), 21 deletions(-) > > diff --git a/block/mirror.c b/block/mirror.c > index 21b4f5d..846e392 100644 > --- a/block/mirror.c > +++ b/block/mirror.c > @@ -601,15 +601,13 @@ static void mirror_throttle(MirrorBlockJob *s) > > static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) > { > - int64_t sector_num, end; > + int64_t offset; > BlockDriverState *base = s->base; > BlockDriverState *bs = s->source; > BlockDriverState *target_bs = blk_bs(s->target); > - int ret, n; > + int ret; > int64_t count; > > - end = s->bdev_length / BDRV_SECTOR_SIZE; > - > if (base == NULL && !bdrv_has_zero_init(target_bs)) { > if (!bdrv_can_write_zeroes_with_unmap(target_bs)) { > bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length); > @@ -617,9 +615,9 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) > } > > s->initial_zeroing_ongoing = true; > - for (sector_num = 0; sector_num < end; ) { > - int nb_sectors = MIN(end - sector_num, > - QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >> BDRV_SECTOR_BITS); > + for (offset = 0; offset < s->bdev_length; ) { > + int bytes = MIN(s->bdev_length - offset, > + QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); > > mirror_throttle(s); > > @@ -635,9 +633,8 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) > continue; > } > > - mirror_do_zero_or_discard(s, sector_num * BDRV_SECTOR_SIZE, > - nb_sectors * BDRV_SECTOR_SIZE, false); > - sector_num += nb_sectors; > + mirror_do_zero_or_discard(s, offset, bytes, false); > + offset += bytes; > } > > mirror_wait_for_all_io(s); > @@ -645,10 +642,10 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) > } > > /* First part, loop on the sectors and initialize the dirty bitmap. */ > - for (sector_num = 0; sector_num < end; ) { > + for (offset = 0; offset < s->bdev_length; ) { > /* Just to make sure we are not exceeding int limit. */ > - int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS, > - end - sector_num); > + int bytes = MIN(s->bdev_length - offset, > + QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); > > mirror_throttle(s); > > @@ -656,20 +653,16 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) > return 0; > } > > - ret = bdrv_is_allocated_above(bs, base, sector_num * BDRV_SECTOR_SIZE, > - nb_sectors * BDRV_SECTOR_SIZE, &count); > + ret = bdrv_is_allocated_above(bs, base, offset, bytes, &count); > if (ret < 0) { > return ret; > } > > - n = DIV_ROUND_UP(count, BDRV_SECTOR_SIZE); > - assert(n > 0); > + count = QEMU_ALIGN_UP(count, BDRV_SECTOR_SIZE); > if (ret == 1) { > - bdrv_set_dirty_bitmap(s->dirty_bitmap, > - sector_num * BDRV_SECTOR_SIZE, > - n * BDRV_SECTOR_SIZE); > + bdrv_set_dirty_bitmap(s->dirty_bitmap, offset, count); > } > - sector_num += n; > + offset += count; > } > return 0; > } > Reviewed-by: John Snow <jsnow@redhat.com>
diff --git a/block/mirror.c b/block/mirror.c index 21b4f5d..846e392 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -601,15 +601,13 @@ static void mirror_throttle(MirrorBlockJob *s) static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) { - int64_t sector_num, end; + int64_t offset; BlockDriverState *base = s->base; BlockDriverState *bs = s->source; BlockDriverState *target_bs = blk_bs(s->target); - int ret, n; + int ret; int64_t count; - end = s->bdev_length / BDRV_SECTOR_SIZE; - if (base == NULL && !bdrv_has_zero_init(target_bs)) { if (!bdrv_can_write_zeroes_with_unmap(target_bs)) { bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length); @@ -617,9 +615,9 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) } s->initial_zeroing_ongoing = true; - for (sector_num = 0; sector_num < end; ) { - int nb_sectors = MIN(end - sector_num, - QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >> BDRV_SECTOR_BITS); + for (offset = 0; offset < s->bdev_length; ) { + int bytes = MIN(s->bdev_length - offset, + QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); mirror_throttle(s); @@ -635,9 +633,8 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) continue; } - mirror_do_zero_or_discard(s, sector_num * BDRV_SECTOR_SIZE, - nb_sectors * BDRV_SECTOR_SIZE, false); - sector_num += nb_sectors; + mirror_do_zero_or_discard(s, offset, bytes, false); + offset += bytes; } mirror_wait_for_all_io(s); @@ -645,10 +642,10 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) } /* First part, loop on the sectors and initialize the dirty bitmap. */ - for (sector_num = 0; sector_num < end; ) { + for (offset = 0; offset < s->bdev_length; ) { /* Just to make sure we are not exceeding int limit. */ - int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS, - end - sector_num); + int bytes = MIN(s->bdev_length - offset, + QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); mirror_throttle(s); @@ -656,20 +653,16 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) return 0; } - ret = bdrv_is_allocated_above(bs, base, sector_num * BDRV_SECTOR_SIZE, - nb_sectors * BDRV_SECTOR_SIZE, &count); + ret = bdrv_is_allocated_above(bs, base, offset, bytes, &count); if (ret < 0) { return ret; } - n = DIV_ROUND_UP(count, BDRV_SECTOR_SIZE); - assert(n > 0); + count = QEMU_ALIGN_UP(count, BDRV_SECTOR_SIZE); if (ret == 1) { - bdrv_set_dirty_bitmap(s->dirty_bitmap, - sector_num * BDRV_SECTOR_SIZE, - n * BDRV_SECTOR_SIZE); + bdrv_set_dirty_bitmap(s->dirty_bitmap, offset, count); } - sector_num += n; + offset += count; } return 0; }
Now that we have adjusted the majority of the calls this function makes to be byte-based, it is easier to read the code if it makes passes over the image using bytes rather than sectors. Signed-off-by: Eric Blake <eblake@redhat.com> --- block/mirror.c | 35 ++++++++++++++--------------------- 1 file changed, 14 insertions(+), 21 deletions(-)