From 03f5d60bbf264ea68e50db2a7b2383a8da5122d2 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 7 Jul 2017 07:44:55 -0500 Subject: [PATCH] backup: Switch backup_do_cow() to byte-based We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Convert another internal function (no semantic change). Signed-off-by: Eric Blake Reviewed-by: John Snow Reviewed-by: Jeff Cody Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/backup.c | 62 +++++++++++++++++++++----------------------------- 1 file changed, 26 insertions(+), 36 deletions(-) diff --git a/block/backup.c b/block/backup.c index 503fbec8c1..f7e14dbe73 100644 --- a/block/backup.c +++ b/block/backup.c @@ -91,7 +91,7 @@ static void cow_request_end(CowRequest *req) } static int coroutine_fn backup_do_cow(BackupBlockJob *job, - int64_t sector_num, int nb_sectors, + int64_t offset, uint64_t bytes, bool *error_is_read, bool is_write_notifier) { @@ -101,34 +101,28 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job, QEMUIOVector bounce_qiov; void *bounce_buffer = NULL; int ret = 0; - int64_t sectors_per_cluster = cluster_size_sectors(job); - int64_t start, end; /* clusters */ + int64_t start, end; /* bytes */ int n; /* bytes */ qemu_co_rwlock_rdlock(&job->flush_rwlock); - start = sector_num / sectors_per_cluster; - end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster); + start = QEMU_ALIGN_DOWN(offset, job->cluster_size); + end = QEMU_ALIGN_UP(bytes + offset, job->cluster_size); - trace_backup_do_cow_enter(job, start * job->cluster_size, - sector_num * BDRV_SECTOR_SIZE, - nb_sectors * BDRV_SECTOR_SIZE); + trace_backup_do_cow_enter(job, start, offset, bytes); - wait_for_overlapping_requests(job, start * job->cluster_size, - end * job->cluster_size); - cow_request_begin(&cow_request, job, start * job->cluster_size, - end * job->cluster_size); + wait_for_overlapping_requests(job, start, end); + cow_request_begin(&cow_request, job, start, end); - for (; start < end; start++) { - if (test_bit(start, job->done_bitmap)) { - trace_backup_do_cow_skip(job, start * job->cluster_size); + for (; start < end; start += job->cluster_size) { + if (test_bit(start / job->cluster_size, job->done_bitmap)) { + trace_backup_do_cow_skip(job, start); continue; /* already copied */ } - trace_backup_do_cow_process(job, start * job->cluster_size); + trace_backup_do_cow_process(job, start); - n = MIN(job->cluster_size, - job->common.len - start * job->cluster_size); + n = MIN(job->cluster_size, job->common.len - start); if (!bounce_buffer) { bounce_buffer = blk_blockalign(blk, job->cluster_size); @@ -137,11 +131,10 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job, iov.iov_len = n; qemu_iovec_init_external(&bounce_qiov, &iov, 1); - ret = blk_co_preadv(blk, start * job->cluster_size, - bounce_qiov.size, &bounce_qiov, + ret = blk_co_preadv(blk, start, bounce_qiov.size, &bounce_qiov, is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0); if (ret < 0) { - trace_backup_do_cow_read_fail(job, start * job->cluster_size, ret); + trace_backup_do_cow_read_fail(job, start, ret); if (error_is_read) { *error_is_read = true; } @@ -149,22 +142,22 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job, } if (buffer_is_zero(iov.iov_base, iov.iov_len)) { - ret = blk_co_pwrite_zeroes(job->target, start * job->cluster_size, + ret = blk_co_pwrite_zeroes(job->target, start, bounce_qiov.size, BDRV_REQ_MAY_UNMAP); } else { - ret = blk_co_pwritev(job->target, start * job->cluster_size, + ret = blk_co_pwritev(job->target, start, bounce_qiov.size, &bounce_qiov, job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0); } if (ret < 0) { - trace_backup_do_cow_write_fail(job, start * job->cluster_size, ret); + trace_backup_do_cow_write_fail(job, start, ret); if (error_is_read) { *error_is_read = false; } goto out; } - set_bit(start, job->done_bitmap); + set_bit(start / job->cluster_size, job->done_bitmap); /* Publish progress, guest I/O counts as progress too. Note that the * offset field is an opaque progress value, it is not a disk offset. @@ -180,8 +173,7 @@ out: cow_request_end(&cow_request); - trace_backup_do_cow_return(job, sector_num * BDRV_SECTOR_SIZE, - nb_sectors * BDRV_SECTOR_SIZE, ret); + trace_backup_do_cow_return(job, offset, bytes, ret); qemu_co_rwlock_unlock(&job->flush_rwlock); @@ -194,14 +186,12 @@ static int coroutine_fn backup_before_write_notify( { BackupBlockJob *job = container_of(notifier, BackupBlockJob, before_write); BdrvTrackedRequest *req = opaque; - int64_t sector_num = req->offset >> BDRV_SECTOR_BITS; - int nb_sectors = req->bytes >> BDRV_SECTOR_BITS; assert(req->bs == blk_bs(job->common.blk)); - assert((req->offset & (BDRV_SECTOR_SIZE - 1)) == 0); - assert((req->bytes & (BDRV_SECTOR_SIZE - 1)) == 0); + assert(QEMU_IS_ALIGNED(req->offset, BDRV_SECTOR_SIZE)); + assert(QEMU_IS_ALIGNED(req->bytes, BDRV_SECTOR_SIZE)); - return backup_do_cow(job, sector_num, nb_sectors, NULL, true); + return backup_do_cow(job, req->offset, req->bytes, NULL, true); } static void backup_set_speed(BlockJob *job, int64_t speed, Error **errp) @@ -406,8 +396,8 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job) if (yield_and_check(job)) { goto out; } - ret = backup_do_cow(job, cluster * sectors_per_cluster, - sectors_per_cluster, &error_is_read, + ret = backup_do_cow(job, cluster * job->cluster_size, + job->cluster_size, &error_is_read, false); if ((ret < 0) && backup_error_action(job, error_is_read, -ret) == @@ -509,8 +499,8 @@ static void coroutine_fn backup_run(void *opaque) if (alloced < 0) { ret = alloced; } else { - ret = backup_do_cow(job, start * sectors_per_cluster, - sectors_per_cluster, &error_is_read, + ret = backup_do_cow(job, start * job->cluster_size, + job->cluster_size, &error_is_read, false); } if (ret < 0) {