[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-block] [PATCH 1/6] block: Support byte-based aio callbacks
From: |
Eric Blake |
Subject: |
[Qemu-block] [PATCH 1/6] block: Support byte-based aio callbacks |
Date: |
Thu, 15 Feb 2018 13:28:24 -0600 |
We are gradually moving away from sector-based interfaces, towards
byte-based. Add new sector-based aio callbacks for read and write,
to match the fact that bdrv_aio_pdiscard is already byte-based.
Ideally, drivers should be converted to use coroutine callbacks
rather than aio; but that is not quite as trivial (if we do that
conversion, the null-aio driver will disappear), so for the
short term, converting the signature but keeping things with aio
is easier. Once all drivers are converted, the sector-based aio
callbacks will be removed.
Signed-off-by: Eric Blake <address@hidden>
---
include/block/block_int.h | 6 ++++++
block/io.c | 37 +++++++++++++++++++++++++++----------
2 files changed, 33 insertions(+), 10 deletions(-)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 5ae7738cf8d..c882dc4232d 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -137,9 +137,15 @@ struct BlockDriver {
BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque);
+ BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
+ BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque);
+ BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
+ BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs,
diff --git a/block/io.c b/block/io.c
index 4d3d1f640a3..84a4caa72b7 100644
--- a/block/io.c
+++ b/block/io.c
@@ -934,9 +934,11 @@ static int coroutine_fn
bdrv_driver_preadv(BlockDriverState *bs,
sector_num = offset >> BDRV_SECTOR_BITS;
nb_sectors = bytes >> BDRV_SECTOR_BITS;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
+ if (!drv->bdrv_aio_preadv) {
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
+ }
if (drv->bdrv_co_readv) {
return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
@@ -946,8 +948,13 @@ static int coroutine_fn
bdrv_driver_preadv(BlockDriverState *bs,
.coroutine = qemu_coroutine_self(),
};
- acb = bs->drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
- bdrv_co_io_em_complete, &co);
+ if (drv->bdrv_aio_preadv) {
+ acb = bs->drv->bdrv_aio_preadv(bs, offset, bytes, qiov, flags,
+ bdrv_co_io_em_complete, &co);
+ } else {
+ acb = bs->drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
+ bdrv_co_io_em_complete, &co);
+ }
if (acb == NULL) {
return -EIO;
} else {
@@ -982,9 +989,11 @@ static int coroutine_fn
bdrv_driver_pwritev(BlockDriverState *bs,
sector_num = offset >> BDRV_SECTOR_BITS;
nb_sectors = bytes >> BDRV_SECTOR_BITS;
- assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
+ if (!drv->bdrv_aio_pwritev) {
+ assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+ assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
+ }
if (drv->bdrv_co_writev_flags) {
ret = drv->bdrv_co_writev_flags(bs, sector_num, nb_sectors, qiov,
@@ -999,8 +1008,16 @@ static int coroutine_fn
bdrv_driver_pwritev(BlockDriverState *bs,
.coroutine = qemu_coroutine_self(),
};
- acb = bs->drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
- bdrv_co_io_em_complete, &co);
+ if (drv->bdrv_aio_pwritev) {
+ acb = bs->drv->bdrv_aio_pwritev(bs, offset, bytes, qiov,
+ flags & bs->supported_write_flags,
+ bdrv_co_io_em_complete, &co);
+ flags &= ~bs->supported_write_flags;
+ } else {
+ assert(!bs->supported_write_flags);
+ acb = bs->drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
+ bdrv_co_io_em_complete, &co);
+ }
if (acb == NULL) {
ret = -EIO;
} else {
--
2.14.3
- [Qemu-block] [PATCH 0/6] block: byte-based AIO read/write, Eric Blake, 2018/02/15
- [Qemu-block] [PATCH 6/6] block: Drop last of the sector-based aio callbacks, Eric Blake, 2018/02/15
- [Qemu-block] [PATCH 3/6] null: Switch to byte-based read/write, Eric Blake, 2018/02/15
- [Qemu-block] [PATCH 5/6] vxhs: Switch to byte-based callbacks, Eric Blake, 2018/02/15
- [Qemu-block] [PATCH 1/6] block: Support byte-based aio callbacks,
Eric Blake <=
- [Qemu-block] [PATCH 4/6] rbd: Switch to byte-based callbacks, Eric Blake, 2018/02/15
- [Qemu-block] [PATCH 2/6] file-win32: Switch to byte-based callbacks, Eric Blake, 2018/02/15