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[Qemu-devel] [PATCH 01/17] block: Convert bdrv_co_discard() to byte-base
From: |
Eric Blake |
Subject: |
[Qemu-devel] [PATCH 01/17] block: Convert bdrv_co_discard() to byte-based |
Date: |
Wed, 22 Jun 2016 09:50:58 -0600 |
Another step towards byte-based interfaces everywhere. Replace
the sector-based bdrv_co_discard() with a new byte-based
bdrv_co_pdiscard(), which silently ignores any unaligned head
or tail. Driver callbacks will be converted in followup patches.
By calculating the alignment outside of the loop, and clamping
the max discard to an aligned value, we can simplify the actions
done within the loop.
Signed-off-by: Eric Blake <address@hidden>
---
include/block/block.h | 2 +-
block/blkreplay.c | 3 ++-
block/block-backend.c | 3 ++-
block/io.c | 67 +++++++++++++++++++++++++++------------------------
block/raw_bsd.c | 3 ++-
5 files changed, 42 insertions(+), 36 deletions(-)
diff --git a/include/block/block.h b/include/block/block.h
index c1d4648..b8df2fb 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -345,7 +345,7 @@ void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
void bdrv_drain_all(void);
int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
-int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
+int bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, int count);
int bdrv_has_zero_init_1(BlockDriverState *bs);
int bdrv_has_zero_init(BlockDriverState *bs);
bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 525c2d5..28024c8 100755
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -118,7 +118,8 @@ static int coroutine_fn
blkreplay_co_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors)
{
uint64_t reqid = request_id++;
- int ret = bdrv_co_discard(bs->file->bs, sector_num, nb_sectors);
+ int ret = bdrv_co_pdiscard(bs->file->bs, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS);
block_request_create(reqid, bs, qemu_coroutine_self());
qemu_coroutine_yield();
diff --git a/block/block-backend.c b/block/block-backend.c
index e042544..f44e7e6 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1108,7 +1108,8 @@ int blk_co_discard(BlockBackend *blk, int64_t sector_num,
int nb_sectors)
return ret;
}
- return bdrv_co_discard(blk_bs(blk), sector_num, nb_sectors);
+ return bdrv_co_pdiscard(blk_bs(blk), sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS);
}
int blk_co_flush(BlockBackend *blk)
diff --git a/block/io.c b/block/io.c
index 727a2d4..22869b8 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2193,7 +2193,8 @@ static void coroutine_fn bdrv_aio_discard_co_entry(void
*opaque)
BlockAIOCBCoroutine *acb = opaque;
BlockDriverState *bs = acb->common.bs;
- acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
+ acb->req.error = bdrv_co_pdiscard(bs, acb->req.sector << BDRV_SECTOR_BITS,
+ acb->req.nb_sectors << BDRV_SECTOR_BITS);
bdrv_co_complete(acb);
}
@@ -2367,20 +2368,22 @@ static void coroutine_fn bdrv_discard_co_entry(void
*opaque)
{
DiscardCo *rwco = opaque;
- rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
+ rwco->ret = bdrv_co_pdiscard(rwco->bs, rwco->sector_num <<
BDRV_SECTOR_BITS,
+ rwco->nb_sectors << BDRV_SECTOR_BITS);
}
-int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors)
+int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset,
+ int count)
{
BdrvTrackedRequest req;
- int max_discard, ret;
+ int max_pdiscard, ret;
+ int head, align;
if (!bs->drv) {
return -ENOMEDIUM;
}
- ret = bdrv_check_request(bs, sector_num, nb_sectors);
+ ret = bdrv_check_byte_request(bs, offset, count);
if (ret < 0) {
return ret;
} else if (bs->read_only) {
@@ -2397,45 +2400,45 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs,
int64_t sector_num,
return 0;
}
- tracked_request_begin(&req, bs, sector_num << BDRV_SECTOR_BITS,
- nb_sectors << BDRV_SECTOR_BITS,
BDRV_TRACKED_DISCARD);
+ /* Discard is advisory, so ignore any unaligned head or tail */
+ align = MAX(BDRV_SECTOR_SIZE,
+ MAX(bs->bl.pdiscard_alignment, bs->bl.request_alignment));
+ assert(is_power_of_2(align));
+ head = MIN(count, -offset & (align - 1));
+ if (head) {
+ count -= head;
+ offset += head;
+ }
+ count = QEMU_ALIGN_DOWN(count, align);
+ if (!count) {
+ return 0;
+ }
+
+ tracked_request_begin(&req, bs, offset, count, BDRV_TRACKED_DISCARD);
ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req);
if (ret < 0) {
goto out;
}
- max_discard = MIN_NON_ZERO(bs->bl.max_pdiscard >> BDRV_SECTOR_BITS,
- BDRV_REQUEST_MAX_SECTORS);
- while (nb_sectors > 0) {
+ max_pdiscard = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_pdiscard, INT_MAX),
+ align);
+
+ while (count > 0) {
int ret;
- int num = nb_sectors;
- int discard_alignment = bs->bl.pdiscard_alignment >> BDRV_SECTOR_BITS;
-
- /* align request */
- if (discard_alignment &&
- num >= discard_alignment &&
- sector_num % discard_alignment) {
- if (num > discard_alignment) {
- num = discard_alignment;
- }
- num -= sector_num % discard_alignment;
- }
-
- /* limit request size */
- if (num > max_discard) {
- num = max_discard;
- }
+ int num = MIN(count, max_pdiscard);
if (bs->drv->bdrv_co_discard) {
- ret = bs->drv->bdrv_co_discard(bs, sector_num, num);
+ ret = bs->drv->bdrv_co_discard(bs, offset >> BDRV_SECTOR_BITS,
+ num >> BDRV_SECTOR_BITS);
} else {
BlockAIOCB *acb;
CoroutineIOCompletion co = {
.coroutine = qemu_coroutine_self(),
};
- acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
+ acb = bs->drv->bdrv_aio_discard(bs, offset >> BDRV_SECTOR_BITS,
+ num >> BDRV_SECTOR_BITS,
bdrv_co_io_em_complete, &co);
if (acb == NULL) {
ret = -EIO;
@@ -2449,8 +2452,8 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs,
int64_t sector_num,
goto out;
}
- sector_num += num;
- nb_sectors -= num;
+ offset += num;
+ count -= num;
}
ret = 0;
out:
diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index 47a8352..907172e 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -137,7 +137,8 @@ static int coroutine_fn
raw_co_pwrite_zeroes(BlockDriverState *bs,
static int coroutine_fn raw_co_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors)
{
- return bdrv_co_discard(bs->file->bs, sector_num, nb_sectors);
+ return bdrv_co_pdiscard(bs->file->bs, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors << BDRV_SECTOR_BITS);
}
static int64_t raw_getlength(BlockDriverState *bs)
--
2.5.5
- [Qemu-devel] [PATCH 00/17] byte-based block discard, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 09/17] block: Add .bdrv_co_pdiscard() driver callback, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 07/17] rbd: Switch rbd_start_aio() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 10/17] blkreplay: Switch .bdrv_co_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 04/17] block: Convert bdrv_aio_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 08/17] block: Convert .bdrv_aio_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 12/17] iscsi: Switch .bdrv_co_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 02/17] block: Convert bdrv_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 05/17] block: Convert BB interface to byte-based discards, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 03/17] block: Switch BlockRequest to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 01/17] block: Convert bdrv_co_discard() to byte-based,
Eric Blake <=
- [Qemu-devel] [PATCH 06/17] raw-posix: Switch paio_submit() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 13/17] nbd: Switch .bdrv_co_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 15/17] raw_bsd: Switch .bdrv_co_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 17/17] block: Kill .bdrv_co_discard(), Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 14/17] qcow2: Switch .bdrv_co_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 16/17] sheepdog: Switch .bdrv_co_discard() to byte-based, Eric Blake, 2016/06/22
- [Qemu-devel] [PATCH 11/17] gluster: Switch .bdrv_co_discard() to byte-based, Eric Blake, 2016/06/22