From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42462) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bKSdR-0001C1-Ec for qemu-devel@nongnu.org; Tue, 05 Jul 2016 11:51:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bKSdO-0006dX-Jz for qemu-devel@nongnu.org; Tue, 05 Jul 2016 11:51:40 -0400 From: Kevin Wolf Date: Tue, 5 Jul 2016 17:50:30 +0200 Message-Id: <1467733852-27097-22-git-send-email-kwolf@redhat.com> In-Reply-To: <1467733852-27097-1-git-send-email-kwolf@redhat.com> References: <1467733852-27097-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 21/43] block: Move request_alignment into BlockLimit List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Eric Blake It makes more sense to have ALL block size limit constraints in the same struct. Improve the documentation while at it. Simplify a couple of conditionals, now that we have audited and documented that request_alignment is always non-zero. Signed-off-by: Eric Blake Reviewed-by: Fam Zheng Signed-off-by: Kevin Wolf --- block.c | 2 +- block/blkdebug.c | 2 +- block/bochs.c | 2 +- block/cloop.c | 2 +- block/dmg.c | 2 +- block/io.c | 14 +++++++------- block/iscsi.c | 2 +- block/qcow2.c | 2 +- block/raw-posix.c | 16 ++++++++-------- block/raw-win32.c | 6 +++--- block/vvfat.c | 2 +- include/block/block_int.h | 22 +++++++++++++--------- 12 files changed, 39 insertions(+), 35 deletions(-) diff --git a/block.c b/block.c index c2fbf06..34894ad 100644 --- a/block.c +++ b/block.c @@ -1016,7 +1016,7 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file, assert(bdrv_opt_mem_align(bs) != 0); assert(bdrv_min_mem_align(bs) != 0); - assert(is_power_of_2(bs->request_alignment) || bdrv_is_sg(bs)); + assert(is_power_of_2(bs->bl.request_alignment)); qemu_opts_del(opts); return 0; diff --git a/block/blkdebug.c b/block/blkdebug.c index 54b6870..b6ecee3 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -726,7 +726,7 @@ static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp) BDRVBlkdebugState *s = bs->opaque; if (s->align) { - bs->request_alignment = s->align; + bs->bl.request_alignment = s->align; } } diff --git a/block/bochs.c b/block/bochs.c index 182c50b..4194f1d 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -190,7 +190,7 @@ fail: static void bochs_refresh_limits(BlockDriverState *bs, Error **errp) { - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ } static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num) diff --git a/block/cloop.c b/block/cloop.c index d574003..b5dc286 100644 --- a/block/cloop.c +++ b/block/cloop.c @@ -200,7 +200,7 @@ fail: static void cloop_refresh_limits(BlockDriverState *bs, Error **errp) { - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ } static inline int cloop_read_block(BlockDriverState *bs, int block_num) diff --git a/block/dmg.c b/block/dmg.c index 1e53cd8..9612c21 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -548,7 +548,7 @@ fail: static void dmg_refresh_limits(BlockDriverState *bs, Error **errp) { - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ } static inline int is_sector_in_chunk(BDRVDMGState* s, diff --git a/block/io.c b/block/io.c index 69dbbd3..b9e53e3 100644 --- a/block/io.c +++ b/block/io.c @@ -90,7 +90,7 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) } /* Default alignment based on whether driver has byte interface */ - bs->request_alignment = drv->bdrv_co_preadv ? 1 : 512; + bs->bl.request_alignment = drv->bdrv_co_preadv ? 1 : 512; /* Take some limits from the children as a default */ if (bs->file) { @@ -459,7 +459,7 @@ static int bdrv_get_cluster_size(BlockDriverState *bs) ret = bdrv_get_info(bs, &bdi); if (ret < 0 || bdi.cluster_size == 0) { - return bs->request_alignment; + return bs->bl.request_alignment; } else { return bdi.cluster_size; } @@ -1068,7 +1068,7 @@ int coroutine_fn bdrv_co_preadv(BlockDriverState *bs, BlockDriver *drv = bs->drv; BdrvTrackedRequest req; - uint64_t align = bs->request_alignment; + uint64_t align = bs->bl.request_alignment; uint8_t *head_buf = NULL; uint8_t *tail_buf = NULL; QEMUIOVector local_qiov; @@ -1164,8 +1164,8 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, int tail = 0; int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX); - int alignment = MAX(bs->bl.pwrite_zeroes_alignment ?: 1, - bs->request_alignment); + int alignment = MAX(bs->bl.pwrite_zeroes_alignment, + bs->bl.request_alignment); assert(is_power_of_2(alignment)); head = offset & (alignment - 1); @@ -1324,7 +1324,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, uint8_t *buf = NULL; QEMUIOVector local_qiov; struct iovec iov; - uint64_t align = bs->request_alignment; + uint64_t align = bs->bl.request_alignment; unsigned int head_padding_bytes, tail_padding_bytes; int ret = 0; @@ -1411,7 +1411,7 @@ int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs, BdrvRequestFlags flags) { BdrvTrackedRequest req; - uint64_t align = bs->request_alignment; + uint64_t align = bs->bl.request_alignment; uint8_t *head_buf = NULL; uint8_t *tail_buf = NULL; QEMUIOVector local_qiov; diff --git a/block/iscsi.c b/block/iscsi.c index 342f6b8..b73fd0a 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -1705,7 +1705,7 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp) IscsiLun *iscsilun = bs->opaque; uint64_t max_xfer_len = iscsilun->use_16_for_rw ? 0xffffffff : 0xffff; - bs->request_alignment = iscsilun->block_size; + bs->bl.request_alignment = iscsilun->block_size; if (iscsilun->bl.max_xfer_len) { max_xfer_len = MIN(max_xfer_len, iscsilun->bl.max_xfer_len); diff --git a/block/qcow2.c b/block/qcow2.c index 48f80b6..fdf13cb 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1201,7 +1201,7 @@ static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) if (bs->encrypted) { /* Encryption works on a sector granularity */ - bs->request_alignment = BDRV_SECTOR_SIZE; + bs->bl.request_alignment = BDRV_SECTOR_SIZE; } bs->bl.pwrite_zeroes_alignment = s->cluster_size; } diff --git a/block/raw-posix.c b/block/raw-posix.c index 8da2f94..d3d7cce 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -302,22 +302,22 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp) /* For SCSI generic devices the alignment is not really used. With buffered I/O, we don't have any restrictions. */ if (bdrv_is_sg(bs) || !s->needs_alignment) { - bs->request_alignment = 1; + bs->bl.request_alignment = 1; s->buf_align = 1; return; } - bs->request_alignment = 0; + bs->bl.request_alignment = 0; s->buf_align = 0; /* Let's try to use the logical blocksize for the alignment. */ - if (probe_logical_blocksize(fd, &bs->request_alignment) < 0) { - bs->request_alignment = 0; + if (probe_logical_blocksize(fd, &bs->bl.request_alignment) < 0) { + bs->bl.request_alignment = 0; } #ifdef CONFIG_XFS if (s->is_xfs) { struct dioattr da; if (xfsctl(NULL, fd, XFS_IOC_DIOINFO, &da) >= 0) { - bs->request_alignment = da.d_miniosz; + bs->bl.request_alignment = da.d_miniosz; /* The kernel returns wrong information for d_mem */ /* s->buf_align = da.d_mem; */ } @@ -337,19 +337,19 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp) qemu_vfree(buf); } - if (!bs->request_alignment) { + if (!bs->bl.request_alignment) { size_t align; buf = qemu_memalign(s->buf_align, max_align); for (align = 512; align <= max_align; align <<= 1) { if (raw_is_io_aligned(fd, buf, align)) { - bs->request_alignment = align; + bs->bl.request_alignment = align; break; } } qemu_vfree(buf); } - if (!s->buf_align || !bs->request_alignment) { + if (!s->buf_align || !bs->bl.request_alignment) { error_setg(errp, "Could not find working O_DIRECT alignment. " "Try cache.direct=off."); } diff --git a/block/raw-win32.c b/block/raw-win32.c index 88382d9..62edb1a 100644 --- a/block/raw-win32.c +++ b/block/raw-win32.c @@ -230,14 +230,14 @@ static void raw_probe_alignment(BlockDriverState *bs, Error **errp) BOOL status; if (s->type == FTYPE_CD) { - bs->request_alignment = 2048; + bs->bl.request_alignment = 2048; return; } if (s->type == FTYPE_HARDDISK) { status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX, NULL, 0, &dg, sizeof(dg), &count, NULL); if (status != 0) { - bs->request_alignment = dg.Geometry.BytesPerSector; + bs->bl.request_alignment = dg.Geometry.BytesPerSector; return; } /* try GetDiskFreeSpace too */ @@ -247,7 +247,7 @@ static void raw_probe_alignment(BlockDriverState *bs, Error **errp) GetDiskFreeSpace(s->drive_path, §orsPerCluster, &dg.Geometry.BytesPerSector, &freeClusters, &totalClusters); - bs->request_alignment = dg.Geometry.BytesPerSector; + bs->bl.request_alignment = dg.Geometry.BytesPerSector; } } diff --git a/block/vvfat.c b/block/vvfat.c index 4d44636..fc948cb 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -1210,7 +1210,7 @@ fail: static void vvfat_refresh_limits(BlockDriverState *bs, Error **errp) { - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ } static inline void vvfat_close_current_file(BDRVVVFATState *s) diff --git a/include/block/block_int.h b/include/block/block_int.h index a3e69fd..8f061eb 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -324,6 +324,12 @@ struct BlockDriver { }; typedef struct BlockLimits { + /* Alignment requirement, in bytes, for offset/length of I/O + * requests. Must be a power of 2 less than INT_MAX; defaults to + * 1 for drivers with modern byte interfaces, and to 512 + * otherwise. */ + uint32_t request_alignment; + /* maximum number of bytes that can be discarded at once (since it * is signed, it must be < 2G, if set), should be multiple of * pdiscard_alignment, but need not be power of 2. May be 0 if no @@ -332,8 +338,8 @@ typedef struct BlockLimits { /* optimal alignment for discard requests in bytes, must be power * of 2, less than max_pdiscard if that is set, and multiple of - * bs->request_alignment. May be 0 if bs->request_alignment is - * good enough */ + * bl.request_alignment. May be 0 if bl.request_alignment is good + * enough */ uint32_t pdiscard_alignment; /* maximum number of bytes that can zeroized at once (since it is @@ -343,12 +349,12 @@ typedef struct BlockLimits { /* optimal alignment for write zeroes requests in bytes, must be * power of 2, less than max_pwrite_zeroes if that is set, and - * multiple of bs->request_alignment. May be 0 if - * bs->request_alignment is good enough */ + * multiple of bl.request_alignment. May be 0 if + * bl.request_alignment is good enough */ uint32_t pwrite_zeroes_alignment; /* optimal transfer length in bytes (must be power of 2, and - * multiple of bs->request_alignment), or 0 if no preferred size */ + * multiple of bl.request_alignment), or 0 if no preferred size */ uint32_t opt_transfer; /* maximal transfer length in bytes (need not be power of 2, but @@ -356,10 +362,10 @@ typedef struct BlockLimits { * For now, anything larger than INT_MAX is clamped down. */ uint32_t max_transfer; - /* memory alignment so that no bounce buffer is needed */ + /* memory alignment, in bytes so that no bounce buffer is needed */ size_t min_mem_alignment; - /* memory alignment for bounce buffer */ + /* memory alignment, in bytes, for bounce buffer */ size_t opt_mem_alignment; /* maximum number of iovec elements */ @@ -465,8 +471,6 @@ struct BlockDriverState { /* I/O Limits */ BlockLimits bl; - /* Alignment requirement for offset/length of I/O requests */ - unsigned int request_alignment; /* Flags honored during pwrite (so far: BDRV_REQ_FUA) */ unsigned int supported_write_flags; /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA, -- 1.8.3.1