| Message ID | 20220811150044.1704013-4-alexander.ivanov@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | parallels: Refactor the code of images checks and fix a bug | expand |
Use generic infrastructure for BAT writing in parallels_co_check() On 11.08.2022 17:00, Alexander Ivanov wrote: > It's too costly to write all the BAT to the disk. Let the flush function > write only dirty blocks. > Use parallels_set_bat_entry for setting a BAT entry and marking a relevant > block as dirty. > Move bdrv_co_flush call outside the locked area. This is not correct too: - with a lot of cases inside parallels_co_check, which will be split to smaller functions, we would like to avoid writing BAT once each stage is complete Thus the comment should look like the following: "BAT is written in the context of conventional operations over the image inside bdrv_co_flush() when it calls parallels_co_flush_to_os() callback. Thus we should not modify BAT array directly, but call parallels_set_bat_entry() helper and bdrv_co_flush() further on. After that there is no need to manually write BAT and track its modification. This makes code more generic and allows to split parallels_set_bat_entry() for independent pieces." > v2: Patch order was changed so the replacement is done in parallels_co_check. > Now we use a helper to set BAT entry and mark the block dirty. Same note about changelog as n other patches. Side note. I like Linux kernel a lot and there is a good guide in. Please look how commit message https://www.kernel.org/doc/html/latest/process/submitting-patches.html May be you could spend some more time on commit message. With a better message: Reviewed-by: Denis V. Lunev <den@openvz.org> > Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com> > --- > block/parallels.c | 19 +++++++------------ > 1 file changed, 7 insertions(+), 12 deletions(-) > > diff --git a/block/parallels.c b/block/parallels.c > index 7f68f3cbc9..6879ea4597 100644 > --- a/block/parallels.c > +++ b/block/parallels.c > @@ -428,7 +428,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, > int64_t size, prev_off, high_off; > int ret; > uint32_t i; > - bool flush_bat = false; > > size = bdrv_getlength(bs->file->bs); > if (size < 0) { > @@ -467,9 +466,8 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, > res->corruptions++; > if (fix & BDRV_FIX_ERRORS) { > prev_off = 0; > - s->bat_bitmap[i] = 0; > + parallels_set_bat_entry(s, i, 0); > res->corruptions_fixed++; > - flush_bat = true; > continue; > } > } > @@ -485,15 +483,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, > prev_off = off; > } > > - ret = 0; > - if (flush_bat) { > - ret = bdrv_co_pwrite_sync(bs->file, 0, s->header_size, s->header, 0); > - if (ret < 0) { > - res->check_errors++; > - goto out; > - } > - } > - > res->image_end_offset = high_off + s->cluster_size; > if (size > res->image_end_offset) { > int64_t count; > @@ -522,6 +511,12 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, > > out: > qemu_co_mutex_unlock(&s->lock); > + > + ret = bdrv_co_flush(bs); > + if (ret < 0) { > + res->check_errors++; > + } > + > return ret; > } >
diff --git a/block/parallels.c b/block/parallels.c index 7f68f3cbc9..6879ea4597 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -428,7 +428,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, int64_t size, prev_off, high_off; int ret; uint32_t i; - bool flush_bat = false; size = bdrv_getlength(bs->file->bs); if (size < 0) { @@ -467,9 +466,8 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, res->corruptions++; if (fix & BDRV_FIX_ERRORS) { prev_off = 0; - s->bat_bitmap[i] = 0; + parallels_set_bat_entry(s, i, 0); res->corruptions_fixed++; - flush_bat = true; continue; } } @@ -485,15 +483,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, prev_off = off; } - ret = 0; - if (flush_bat) { - ret = bdrv_co_pwrite_sync(bs->file, 0, s->header_size, s->header, 0); - if (ret < 0) { - res->check_errors++; - goto out; - } - } - res->image_end_offset = high_off + s->cluster_size; if (size > res->image_end_offset) { int64_t count; @@ -522,6 +511,12 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs, out: qemu_co_mutex_unlock(&s->lock); + + ret = bdrv_co_flush(bs); + if (ret < 0) { + res->check_errors++; + } + return ret; }
It's too costly to write all the BAT to the disk. Let the flush function write only dirty blocks. Use parallels_set_bat_entry for setting a BAT entry and marking a relevant block as dirty. Move bdrv_co_flush call outside the locked area. v2: Patch order was changed so the replacement is done in parallels_co_check. Now we use a helper to set BAT entry and mark the block dirty. Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com> --- block/parallels.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-)