From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42026) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fRAWN-0000Ii-It for qemu-devel@nongnu.org; Fri, 08 Jun 2018 02:05:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fRAWL-0008Pu-Ld for qemu-devel@nongnu.org; Fri, 08 Jun 2018 02:05:11 -0400 From: Fam Zheng Date: Fri, 8 Jun 2018 14:04:14 +0800 Message-Id: <20180608060417.10170-4-famz@redhat.com> In-Reply-To: <20180608060417.10170-1-famz@redhat.com> References: <20180608060417.10170-1-famz@redhat.com> Subject: [Qemu-devel] [PATCH 3/6] block-backend: Refactor AIO emulation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Fam Zheng , Kevin Wolf , Max Reitz , Jeff Cody , Stefan Hajnoczi BlkRwCo fields are multi-purposed. @offset is sometimes used to pass the 'req' number for blk_ioctl and blk_aio_ioctl; @iobuf is sometimes the pointer for QEMUIOVector @qiov sometimes the ioctl @buf. This is not as clean as it can be. As the coming copy range emulation wants to add more differentiation in parameters, refactor a bit. Move the per-request fields to a union and create one struct for each type. While at it also move the bytes parameter from BlkAioEmAIOCB to BlkRwCo. Signed-off-by: Fam Zheng --- block/block-backend.c | 211 +++++++++++++++++++++++++++--------------- 1 file changed, 134 insertions(+), 77 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index d55c328736..e20a204bee 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1192,62 +1192,79 @@ int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset, typedef struct BlkRwCo { BlockBackend *blk; - int64_t offset; - void *iobuf; int ret; - BdrvRequestFlags flags; + + union { + struct { + int64_t offset; + int bytes; + QEMUIOVector *qiov; + BdrvRequestFlags flags; + } prwv; + + struct { + int64_t offset; + int bytes; + void *buf; + BdrvRequestFlags flags; + } prw; + + struct { + unsigned long int req; + void *buf; + } ioctl; + }; + } BlkRwCo; static void blk_read_entry(void *opaque) { BlkRwCo *rwco = opaque; - QEMUIOVector *qiov = rwco->iobuf; + QEMUIOVector qiov; + struct iovec iov; - rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, qiov->size, - qiov, rwco->flags); + iov = (struct iovec) { + .iov_base = rwco->prw.buf, + .iov_len = rwco->prw.bytes, + }; + qemu_iovec_init_external(&qiov, &iov, 1); + + rwco->ret = blk_co_preadv(rwco->blk, rwco->prw.offset, rwco->prw.bytes, + &qiov, rwco->prw.flags); } static void blk_write_entry(void *opaque) { BlkRwCo *rwco = opaque; - QEMUIOVector *qiov = rwco->iobuf; - - rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, qiov->size, - qiov, rwco->flags); -} - -static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, - int64_t bytes, CoroutineEntry co_entry, - BdrvRequestFlags flags) -{ QEMUIOVector qiov; struct iovec iov; - BlkRwCo rwco; iov = (struct iovec) { - .iov_base = buf, - .iov_len = bytes, + .iov_base = rwco->prw.buf, + .iov_len = rwco->prw.bytes, }; qemu_iovec_init_external(&qiov, &iov, 1); - rwco = (BlkRwCo) { - .blk = blk, - .offset = offset, - .iobuf = &qiov, - .flags = flags, - .ret = NOT_DONE, - }; + rwco->ret = blk_co_pwritev(rwco->blk, rwco->prw.offset, rwco->prw.bytes, + &qiov, rwco->prw.flags); +} +static int blk_prw(BlockBackend *blk, BlkRwCo *rwco, + CoroutineEntry co_entry) +{ + + rwco->blk = blk; + rwco->ret = NOT_DONE; if (qemu_in_coroutine()) { /* Fast-path if already in coroutine context */ - co_entry(&rwco); + co_entry(rwco); } else { - Coroutine *co = qemu_coroutine_create(co_entry, &rwco); + Coroutine *co = qemu_coroutine_create(co_entry, rwco); bdrv_coroutine_enter(blk_bs(blk), co); - BDRV_POLL_WHILE(blk_bs(blk), rwco.ret == NOT_DONE); + BDRV_POLL_WHILE(blk_bs(blk), rwco->ret == NOT_DONE); } - return rwco.ret; + return rwco->ret; } int blk_pread_unthrottled(BlockBackend *blk, int64_t offset, uint8_t *buf, @@ -1269,8 +1286,12 @@ int blk_pread_unthrottled(BlockBackend *blk, int64_t offset, uint8_t *buf, int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset, int bytes, BdrvRequestFlags flags) { - return blk_prw(blk, offset, NULL, bytes, blk_write_entry, - flags | BDRV_REQ_ZERO_WRITE); + BlkRwCo rwco = (BlkRwCo) { + .prwv.offset = offset, + .prwv.bytes = bytes, + .prwv.flags = flags | BDRV_REQ_ZERO_WRITE, + }; + return blk_prw(blk, &rwco, blk_write_entry); } int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags) @@ -1316,7 +1337,6 @@ BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, typedef struct BlkAioEmAIOCB { BlockAIOCB common; BlkRwCo rwco; - int bytes; bool has_returned; } BlkAioEmAIOCB; @@ -1340,9 +1360,8 @@ static void blk_aio_complete_bh(void *opaque) blk_aio_complete(acb); } -static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes, - void *iobuf, CoroutineEntry co_entry, - BdrvRequestFlags flags, +static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, const BlkRwCo *rwco, + CoroutineEntry co_entry, BlockCompletionFunc *cb, void *opaque) { BlkAioEmAIOCB *acb; @@ -1350,14 +1369,9 @@ static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes, blk_inc_in_flight(blk); acb = blk_aio_get(&blk_aio_em_aiocb_info, blk, cb, opaque); - acb->rwco = (BlkRwCo) { - .blk = blk, - .offset = offset, - .iobuf = iobuf, - .flags = flags, - .ret = NOT_DONE, - }; - acb->bytes = bytes; + acb->rwco = *rwco; + acb->rwco.blk = blk; + acb->rwco.ret = NOT_DONE; acb->has_returned = false; co = qemu_coroutine_create(co_entry, acb); @@ -1376,11 +1390,11 @@ static void blk_aio_read_entry(void *opaque) { BlkAioEmAIOCB *acb = opaque; BlkRwCo *rwco = &acb->rwco; - QEMUIOVector *qiov = rwco->iobuf; + QEMUIOVector *qiov = rwco->prwv.qiov; - assert(qiov->size == acb->bytes); - rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, acb->bytes, - qiov, rwco->flags); + assert(qiov->size == rwco->prwv.bytes); + rwco->ret = blk_co_preadv(rwco->blk, rwco->prwv.offset, rwco->prwv.bytes, + qiov, rwco->prwv.flags); blk_aio_complete(acb); } @@ -1388,11 +1402,11 @@ static void blk_aio_write_entry(void *opaque) { BlkAioEmAIOCB *acb = opaque; BlkRwCo *rwco = &acb->rwco; - QEMUIOVector *qiov = rwco->iobuf; + QEMUIOVector *qiov = rwco->prwv.qiov; - assert(!qiov || qiov->size == acb->bytes); - rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, acb->bytes, - qiov, rwco->flags); + assert(!qiov || qiov->size == rwco->prwv.bytes); + rwco->ret = blk_co_pwritev(rwco->blk, rwco->prwv.offset, rwco->prwv.bytes, + qiov, rwco->prwv.flags); blk_aio_complete(acb); } @@ -1400,13 +1414,22 @@ BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset, int count, BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque) { - return blk_aio_prwv(blk, offset, count, NULL, blk_aio_write_entry, - flags | BDRV_REQ_ZERO_WRITE, cb, opaque); + BlkRwCo rwco = (BlkRwCo) { + .prwv.offset = offset, + .prwv.bytes = count, + .prwv.flags = flags | BDRV_REQ_ZERO_WRITE, + }; + return blk_aio_prwv(blk, &rwco, blk_aio_write_entry, cb, opaque); } int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count) { - int ret = blk_prw(blk, offset, buf, count, blk_read_entry, 0); + BlkRwCo rwco = (BlkRwCo) { + .prw.offset = offset, + .prw.bytes = count, + .prw.buf = buf, + }; + int ret = blk_prw(blk, &rwco, blk_read_entry); if (ret < 0) { return ret; } @@ -1416,8 +1439,13 @@ int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count) int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count, BdrvRequestFlags flags) { - int ret = blk_prw(blk, offset, (void *) buf, count, blk_write_entry, - flags); + BlkRwCo rwco = (BlkRwCo) { + .prw.offset = offset, + .prw.bytes = count, + .prw.buf = (void *)buf, + .prw.flags = flags, + }; + int ret = blk_prw(blk, &rwco, blk_write_entry); if (ret < 0) { return ret; } @@ -1455,16 +1483,26 @@ BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset, QEMUIOVector *qiov, BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque) { - return blk_aio_prwv(blk, offset, qiov->size, qiov, - blk_aio_read_entry, flags, cb, opaque); + BlkRwCo rwco = (BlkRwCo) { + .prwv.offset = offset, + .prwv.bytes = qiov->size, + .prwv.flags = flags, + .prwv.qiov = qiov, + }; + return blk_aio_prwv(blk, &rwco, blk_aio_read_entry, cb, opaque); } BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset, QEMUIOVector *qiov, BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque) { - return blk_aio_prwv(blk, offset, qiov->size, qiov, - blk_aio_write_entry, flags, cb, opaque); + BlkRwCo rwco = (BlkRwCo) { + .prwv.offset = offset, + .prwv.bytes = qiov->size, + .prwv.flags = flags, + .prwv.qiov = qiov, + }; + return blk_aio_prwv(blk, &rwco, blk_aio_write_entry, cb, opaque); } static void blk_aio_flush_entry(void *opaque) @@ -1479,7 +1517,8 @@ static void blk_aio_flush_entry(void *opaque) BlockAIOCB *blk_aio_flush(BlockBackend *blk, BlockCompletionFunc *cb, void *opaque) { - return blk_aio_prwv(blk, 0, 0, NULL, blk_aio_flush_entry, 0, cb, opaque); + BlkRwCo rwco = { }; + return blk_aio_prwv(blk, &rwco, blk_aio_flush_entry, cb, opaque); } static void blk_aio_pdiscard_entry(void *opaque) @@ -1487,7 +1526,7 @@ static void blk_aio_pdiscard_entry(void *opaque) BlkAioEmAIOCB *acb = opaque; BlkRwCo *rwco = &acb->rwco; - rwco->ret = blk_co_pdiscard(rwco->blk, rwco->offset, acb->bytes); + rwco->ret = blk_co_pdiscard(rwco->blk, rwco->prwv.offset, rwco->prwv.bytes); blk_aio_complete(acb); } @@ -1495,8 +1534,11 @@ BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes, BlockCompletionFunc *cb, void *opaque) { - return blk_aio_prwv(blk, offset, bytes, NULL, blk_aio_pdiscard_entry, 0, - cb, opaque); + BlkRwCo rwco = (BlkRwCo) { + .prwv.offset = offset, + .prwv.bytes = bytes, + }; + return blk_aio_prwv(blk, &rwco, blk_aio_pdiscard_entry, cb, opaque); } void blk_aio_cancel(BlockAIOCB *acb) @@ -1521,15 +1563,17 @@ int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf) static void blk_ioctl_entry(void *opaque) { BlkRwCo *rwco = opaque; - QEMUIOVector *qiov = rwco->iobuf; - rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset, - qiov->iov[0].iov_base); + rwco->ret = blk_co_ioctl(rwco->blk, rwco->ioctl.req, rwco->ioctl.buf); } int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf) { - return blk_prw(blk, req, buf, 0, blk_ioctl_entry, 0); + BlkRwCo rwco = (BlkRwCo) { + .ioctl.req = req, + .ioctl.buf = buf, + }; + return blk_prw(blk, &rwco, blk_ioctl_entry); } static void blk_aio_ioctl_entry(void *opaque) @@ -1537,7 +1581,7 @@ static void blk_aio_ioctl_entry(void *opaque) BlkAioEmAIOCB *acb = opaque; BlkRwCo *rwco = &acb->rwco; - rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset, rwco->iobuf); + rwco->ret = blk_co_ioctl(rwco->blk, rwco->ioctl.req, rwco->ioctl.buf); blk_aio_complete(acb); } @@ -1545,7 +1589,11 @@ static void blk_aio_ioctl_entry(void *opaque) BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, BlockCompletionFunc *cb, void *opaque) { - return blk_aio_prwv(blk, req, 0, buf, blk_aio_ioctl_entry, 0, cb, opaque); + BlkRwCo rwco = (BlkRwCo) { + .ioctl.req = req, + .ioctl.buf = buf, + }; + return blk_aio_prwv(blk, &rwco, blk_aio_ioctl_entry, cb, opaque); } int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes) @@ -1575,7 +1623,8 @@ static void blk_flush_entry(void *opaque) int blk_flush(BlockBackend *blk) { - return blk_prw(blk, 0, NULL, 0, blk_flush_entry, 0); + BlkRwCo rwco = { }; + return blk_prw(blk, &rwco, blk_flush_entry); } void blk_drain(BlockBackend *blk) @@ -1985,8 +2034,13 @@ int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset, int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf, int count) { - return blk_prw(blk, offset, (void *) buf, count, blk_write_entry, - BDRV_REQ_WRITE_COMPRESSED); + BlkRwCo rwco = (BlkRwCo) { + .prw.offset = offset, + .prw.buf = (void *)buf, + .prw.bytes = count, + .prw.flags = BDRV_REQ_WRITE_COMPRESSED, + }; + return blk_prw(blk, &rwco, blk_write_entry); } int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc, @@ -2003,14 +2057,17 @@ int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc, static void blk_pdiscard_entry(void *opaque) { BlkRwCo *rwco = opaque; - QEMUIOVector *qiov = rwco->iobuf; - rwco->ret = blk_co_pdiscard(rwco->blk, rwco->offset, qiov->size); + rwco->ret = blk_co_pdiscard(rwco->blk, rwco->prw.offset, rwco->prw.bytes); } int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes) { - return blk_prw(blk, offset, NULL, bytes, blk_pdiscard_entry, 0); + BlkRwCo rwco = (BlkRwCo) { + .prw.offset = offset, + .prw.bytes = bytes, + }; + return blk_prw(blk, &rwco, blk_pdiscard_entry); } int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, -- 2.17.0