It makes more sense to have ALL block size limit constraints in the same struct. Improve the documentation while at it.
Note that bdrv_refresh_limits() has to keep things alive across a memset() of BlockLimits. Signed-off-by: Eric Blake <ebl...@redhat.com> --- include/block/block_int.h | 12 ++++++++---- block.c | 4 ++-- block/blkdebug.c | 4 ++-- block/bochs.c | 2 +- block/cloop.c | 2 +- block/dmg.c | 2 +- block/io.c | 12 +++++++----- block/iscsi.c | 2 +- block/raw-posix.c | 16 ++++++++-------- block/raw-win32.c | 6 +++--- block/vvfat.c | 2 +- 11 files changed, 35 insertions(+), 29 deletions(-) diff --git a/include/block/block_int.h b/include/block/block_int.h index 9dc7af4..0bc7ff4 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -322,6 +322,12 @@ struct BlockDriver { }; typedef struct BlockLimits { + /* Alignment requirement, in bytes, for offset/length of I/O + * requests. Must be a power of 2, and should not exceed + * INT_MAX. For now, a value of 0 defaults to 512, but may change + * to default to 1. */ + 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 @@ -353,10 +359,10 @@ typedef struct BlockLimits { * should be multiple of opt_transfer), or 0 for no 32-bit limit */ 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 */ @@ -463,8 +469,6 @@ struct BlockDriverState { /* Whether produces zeros when read beyond eof */ bool zero_beyond_eof; - /* 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, diff --git a/block.c b/block.c index f54bc25..1b56161 100644 --- a/block.c +++ b/block.c @@ -937,7 +937,7 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file, goto fail_opts; } - bs->request_alignment = 512; + bs->bl.request_alignment = 512; bs->zero_beyond_eof = true; bs->read_only = !(bs->open_flags & BDRV_O_RDWR); @@ -1018,7 +1018,7 @@ 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) || bdrv_is_sg(bs)); qemu_opts_del(opts); return 0; diff --git a/block/blkdebug.c b/block/blkdebug.c index 20d25bd..d9bf3ff 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -382,9 +382,9 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags, } /* Set request alignment */ - align = qemu_opt_get_size(opts, "align", bs->request_alignment); + align = qemu_opt_get_size(opts, "align", bs->bl.request_alignment); if (align > 0 && align < INT_MAX && !(align & (align - 1))) { - bs->request_alignment = align; + bs->bl.request_alignment = align; } else { error_setg(errp, "Invalid alignment"); ret = -EINVAL; diff --git a/block/bochs.c b/block/bochs.c index 6c8d0f3..7bf20f5 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -105,7 +105,7 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags, int ret; bs->read_only = 1; // no write support yet - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ ret = bdrv_pread(bs->file->bs, 0, &bochs, sizeof(bochs)); if (ret < 0) { diff --git a/block/cloop.c b/block/cloop.c index ea5a92b..71237f7 100644 --- a/block/cloop.c +++ b/block/cloop.c @@ -67,7 +67,7 @@ static int cloop_open(BlockDriverState *bs, QDict *options, int flags, int ret; bs->read_only = 1; - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ /* read header */ ret = bdrv_pread(bs->file->bs, 128, &s->block_size, 4); diff --git a/block/dmg.c b/block/dmg.c index 1ea5f22..ef2eeb4 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -440,7 +440,7 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, int ret; bs->read_only = 1; - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ s->n_chunks = 0; s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL; diff --git a/block/io.c b/block/io.c index e845ef9..aaeedaa 100644 --- a/block/io.c +++ b/block/io.c @@ -71,8 +71,10 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; Error *local_err = NULL; + uint32_t request_alignment = bs->bl.request_alignment; memset(&bs->bl, 0, sizeof(bs->bl)); + bs->bl.request_alignment = request_alignment; if (!drv) { return; @@ -429,7 +431,7 @@ 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; } @@ -1036,7 +1038,7 @@ int coroutine_fn bdrv_co_preadv(BlockDriverState *bs, BdrvTrackedRequest req; /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ - uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); + uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->bl.request_alignment); uint8_t *head_buf = NULL; uint8_t *tail_buf = NULL; QEMUIOVector local_qiov; @@ -1133,7 +1135,7 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, 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); + bs->bl.request_alignment); assert(is_power_of_2(alignment)); head = offset & (alignment - 1); @@ -1291,7 +1293,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, uint8_t *buf = NULL; QEMUIOVector local_qiov; struct iovec iov; - uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); + uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->bl.request_alignment); unsigned int head_padding_bytes, tail_padding_bytes; int ret = 0; @@ -1379,7 +1381,7 @@ int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs, { BdrvTrackedRequest req; /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ - uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); + uint64_t align = MAX(BDRV_SECTOR_SIZE, 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 1486443..baa3e15 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -1590,7 +1590,7 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags, goto out; } bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun); - bs->request_alignment = iscsilun->block_size; + bs->bl.request_alignment = iscsilun->block_size; /* We don't have any emulation for devices other than disks and CD-ROMs, so * this must be sg ioctl compatible. We force it to be sg, otherwise qemu diff --git a/block/raw-posix.c b/block/raw-posix.c index f3bd5ef..10a3957 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 fd23891..7afdb10 100644 --- a/block/raw-win32.c +++ b/block/raw-win32.c @@ -230,14 +230,14 @@ static void raw_probe_alignment(BlockDriverState *bs) 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) 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 a39dbe6..aed186d 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -1180,7 +1180,7 @@ static int vvfat_open(BlockDriverState *bs, QDict *options, int flags, bs->read_only = 0; } - bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */ + bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ bs->total_sectors = cyls * heads * secs; if (init_directories(s, dirname, heads, secs, errp)) { -- 2.5.5