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author | Eric Blake <eblake@redhat.com> | 2017-07-07 07:44:46 -0500 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2017-07-10 13:18:06 +0200 |
commit | b436982f04fb33bb29fcdea190bd1fdc97dc65ef (patch) | |
tree | 08a18161ce64f7aca736a8fbe3a58aa011d2b9d9 | |
parent | 317a6676a279bf71c881992387f75e16e009259c (diff) | |
download | qemu-b436982f04fb33bb29fcdea190bd1fdc97dc65ef.zip qemu-b436982f04fb33bb29fcdea190bd1fdc97dc65ef.tar.gz qemu-b436982f04fb33bb29fcdea190bd1fdc97dc65ef.tar.bz2 |
mirror: Switch MirrorBlockJob to byte-based
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Continue by converting an
internal structure (no semantic change), and all references to the
buffer size.
Add an assertion that our use of s->granularity >> BDRV_SECTOR_BITS
(necessary for interaction with sector-based dirty bitmaps, until
a later patch converts those to be byte-based) does not suffer from
truncation problems.
[checkpatch has a false positive on use of MIN() in this patch]
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r-- | block/mirror.c | 84 |
1 files changed, 42 insertions, 42 deletions
diff --git a/block/mirror.c b/block/mirror.c index b4dfe95..10f4e9b 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -24,9 +24,8 @@ #define SLICE_TIME 100000000ULL /* ns */ #define MAX_IN_FLIGHT 16 -#define MAX_IO_SECTORS ((1 << 20) >> BDRV_SECTOR_BITS) /* 1 Mb */ -#define DEFAULT_MIRROR_BUF_SIZE \ - (MAX_IN_FLIGHT * MAX_IO_SECTORS * BDRV_SECTOR_SIZE) +#define MAX_IO_BYTES (1 << 20) /* 1 Mb */ +#define DEFAULT_MIRROR_BUF_SIZE (MAX_IN_FLIGHT * MAX_IO_BYTES) /* The mirroring buffer is a list of granularity-sized chunks. * Free chunks are organized in a list. @@ -67,11 +66,11 @@ typedef struct MirrorBlockJob { uint64_t last_pause_ns; unsigned long *in_flight_bitmap; int in_flight; - int64_t sectors_in_flight; + int64_t bytes_in_flight; int ret; bool unmap; bool waiting_for_io; - int target_cluster_sectors; + int target_cluster_size; int max_iov; bool initial_zeroing_ongoing; } MirrorBlockJob; @@ -79,8 +78,8 @@ typedef struct MirrorBlockJob { typedef struct MirrorOp { MirrorBlockJob *s; QEMUIOVector qiov; - int64_t sector_num; - int nb_sectors; + int64_t offset; + uint64_t bytes; } MirrorOp; static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, @@ -101,13 +100,12 @@ static void mirror_iteration_done(MirrorOp *op, int ret) MirrorBlockJob *s = op->s; struct iovec *iov; int64_t chunk_num; - int i, nb_chunks, sectors_per_chunk; + int i, nb_chunks; - trace_mirror_iteration_done(s, op->sector_num * BDRV_SECTOR_SIZE, - op->nb_sectors * BDRV_SECTOR_SIZE, ret); + trace_mirror_iteration_done(s, op->offset, op->bytes, ret); s->in_flight--; - s->sectors_in_flight -= op->nb_sectors; + s->bytes_in_flight -= op->bytes; iov = op->qiov.iov; for (i = 0; i < op->qiov.niov; i++) { MirrorBuffer *buf = (MirrorBuffer *) iov[i].iov_base; @@ -115,16 +113,15 @@ static void mirror_iteration_done(MirrorOp *op, int ret) s->buf_free_count++; } - sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; - chunk_num = op->sector_num / sectors_per_chunk; - nb_chunks = DIV_ROUND_UP(op->nb_sectors, sectors_per_chunk); + chunk_num = op->offset / s->granularity; + nb_chunks = DIV_ROUND_UP(op->bytes, s->granularity); bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); if (ret >= 0) { if (s->cow_bitmap) { bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); } if (!s->initial_zeroing_ongoing) { - s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE; + s->common.offset += op->bytes; } } qemu_iovec_destroy(&op->qiov); @@ -144,7 +141,8 @@ static void mirror_write_complete(void *opaque, int ret) if (ret < 0) { BlockErrorAction action; - bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); + bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset >> BDRV_SECTOR_BITS, + op->bytes >> BDRV_SECTOR_BITS); action = mirror_error_action(s, false, -ret); if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { s->ret = ret; @@ -163,7 +161,8 @@ static void mirror_read_complete(void *opaque, int ret) if (ret < 0) { BlockErrorAction action; - bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); + bdrv_set_dirty_bitmap(s->dirty_bitmap, op->offset >> BDRV_SECTOR_BITS, + op->bytes >> BDRV_SECTOR_BITS); action = mirror_error_action(s, true, -ret); if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { s->ret = ret; @@ -171,7 +170,7 @@ static void mirror_read_complete(void *opaque, int ret) mirror_iteration_done(op, ret); } else { - blk_aio_pwritev(s->target, op->sector_num * BDRV_SECTOR_SIZE, &op->qiov, + blk_aio_pwritev(s->target, op->offset, &op->qiov, 0, mirror_write_complete, op); } aio_context_release(blk_get_aio_context(s->common.blk)); @@ -211,7 +210,8 @@ static int mirror_cow_align(MirrorBlockJob *s, align_nb_sectors = max_sectors; if (need_cow) { align_nb_sectors = QEMU_ALIGN_DOWN(align_nb_sectors, - s->target_cluster_sectors); + s->target_cluster_size >> + BDRV_SECTOR_BITS); } } /* Clipping may result in align_nb_sectors unaligned to chunk boundary, but @@ -277,8 +277,8 @@ static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num, /* Allocate a MirrorOp that is used as an AIO callback. */ op = g_new(MirrorOp, 1); op->s = s; - op->sector_num = sector_num; - op->nb_sectors = nb_sectors; + op->offset = sector_num * BDRV_SECTOR_SIZE; + op->bytes = nb_sectors * BDRV_SECTOR_SIZE; /* Now make a QEMUIOVector taking enough granularity-sized chunks * from s->buf_free. @@ -295,7 +295,7 @@ static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num, /* Copy the dirty cluster. */ s->in_flight++; - s->sectors_in_flight += nb_sectors; + s->bytes_in_flight += nb_sectors * BDRV_SECTOR_SIZE; trace_mirror_one_iteration(s, sector_num * BDRV_SECTOR_SIZE, nb_sectors * BDRV_SECTOR_SIZE); @@ -315,19 +315,17 @@ static void mirror_do_zero_or_discard(MirrorBlockJob *s, * so the freeing in mirror_iteration_done is nop. */ op = g_new0(MirrorOp, 1); op->s = s; - op->sector_num = sector_num; - op->nb_sectors = nb_sectors; + op->offset = sector_num * BDRV_SECTOR_SIZE; + op->bytes = nb_sectors * BDRV_SECTOR_SIZE; s->in_flight++; - s->sectors_in_flight += nb_sectors; + s->bytes_in_flight += nb_sectors * BDRV_SECTOR_SIZE; if (is_discard) { blk_aio_pdiscard(s->target, sector_num << BDRV_SECTOR_BITS, - op->nb_sectors << BDRV_SECTOR_BITS, - mirror_write_complete, op); + op->bytes, mirror_write_complete, op); } else { blk_aio_pwrite_zeroes(s->target, sector_num * BDRV_SECTOR_SIZE, - op->nb_sectors * BDRV_SECTOR_SIZE, - s->unmap ? BDRV_REQ_MAY_UNMAP : 0, + op->bytes, s->unmap ? BDRV_REQ_MAY_UNMAP : 0, mirror_write_complete, op); } } @@ -342,8 +340,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) int64_t end = s->bdev_length / BDRV_SECTOR_SIZE; int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)); - int max_io_sectors = MAX((s->buf_size >> BDRV_SECTOR_BITS) / MAX_IN_FLIGHT, - MAX_IO_SECTORS); + int max_io_bytes = MAX(s->buf_size / MAX_IN_FLIGHT, MAX_IO_BYTES); bdrv_dirty_bitmap_lock(s->dirty_bitmap); sector_num = bdrv_dirty_iter_next(s->dbi); @@ -415,9 +412,10 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) nb_chunks * sectors_per_chunk, &io_sectors, &file); if (ret < 0) { - io_sectors = MIN(nb_chunks * sectors_per_chunk, max_io_sectors); + io_sectors = MIN(nb_chunks * sectors_per_chunk, + max_io_bytes >> BDRV_SECTOR_BITS); } else if (ret & BDRV_BLOCK_DATA) { - io_sectors = MIN(io_sectors, max_io_sectors); + io_sectors = MIN(io_sectors, max_io_bytes >> BDRV_SECTOR_BITS); } io_sectors -= io_sectors % sectors_per_chunk; @@ -719,7 +717,6 @@ static void coroutine_fn mirror_run(void *opaque) char backing_filename[2]; /* we only need 2 characters because we are only checking for a NULL string */ int ret = 0; - int target_cluster_size = BDRV_SECTOR_SIZE; if (block_job_is_cancelled(&s->common)) { goto immediate_exit; @@ -771,14 +768,15 @@ static void coroutine_fn mirror_run(void *opaque) bdrv_get_backing_filename(target_bs, backing_filename, sizeof(backing_filename)); if (!bdrv_get_info(target_bs, &bdi) && bdi.cluster_size) { - target_cluster_size = bdi.cluster_size; + s->target_cluster_size = bdi.cluster_size; + } else { + s->target_cluster_size = BDRV_SECTOR_SIZE; } - if (backing_filename[0] && !target_bs->backing - && s->granularity < target_cluster_size) { - s->buf_size = MAX(s->buf_size, target_cluster_size); + if (backing_filename[0] && !target_bs->backing && + s->granularity < s->target_cluster_size) { + s->buf_size = MAX(s->buf_size, s->target_cluster_size); s->cow_bitmap = bitmap_new(length); } - s->target_cluster_sectors = target_cluster_size >> BDRV_SECTOR_BITS; s->max_iov = MIN(bs->bl.max_iov, target_bs->bl.max_iov); s->buf = qemu_try_blockalign(bs, s->buf_size); @@ -814,10 +812,10 @@ static void coroutine_fn mirror_run(void *opaque) cnt = bdrv_get_dirty_count(s->dirty_bitmap); /* s->common.offset contains the number of bytes already processed so * far, cnt is the number of dirty sectors remaining and - * s->sectors_in_flight is the number of sectors currently being + * s->bytes_in_flight is the number of bytes currently being * processed; together those are the current total operation length */ - s->common.len = s->common.offset + - (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE; + s->common.len = s->common.offset + s->bytes_in_flight + + cnt * BDRV_SECTOR_SIZE; /* Note that even when no rate limit is applied we need to yield * periodically with no pending I/O so that bdrv_drain_all() returns. @@ -1150,6 +1148,8 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs, } assert ((granularity & (granularity - 1)) == 0); + /* Granularity must be large enough for sector-based dirty bitmap */ + assert(granularity >= BDRV_SECTOR_SIZE); if (buf_size < 0) { error_setg(errp, "Invalid parameter 'buf-size'"); |