diff options
Diffstat (limited to 'block/backup.c')
| -rw-r--r-- | block/backup.c | 246 |
1 files changed, 107 insertions, 139 deletions
diff --git a/block/backup.c b/block/backup.c index 916817d8b1..715e1d3be8 100644 --- a/block/backup.c +++ b/block/backup.c @@ -112,7 +112,8 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job, int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0; int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0; - hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1); + assert(QEMU_IS_ALIGNED(start, job->cluster_size)); + hbitmap_reset(job->copy_bitmap, start, job->cluster_size); nbytes = MIN(job->cluster_size, job->len - start); if (!*bounce_buffer) { *bounce_buffer = blk_blockalign(blk, job->cluster_size); @@ -145,7 +146,7 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job, return nbytes; fail: - hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1); + hbitmap_set(job->copy_bitmap, start, job->cluster_size); return ret; } @@ -165,16 +166,15 @@ static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job, int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0; assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size)); + assert(QEMU_IS_ALIGNED(start, job->cluster_size)); nbytes = MIN(job->copy_range_size, end - start); nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size); - hbitmap_reset(job->copy_bitmap, start / job->cluster_size, - nr_clusters); + hbitmap_reset(job->copy_bitmap, start, job->cluster_size * nr_clusters); ret = blk_co_copy_range(blk, start, job->target, start, nbytes, read_flags, write_flags); if (ret < 0) { trace_backup_do_cow_copy_range_fail(job, start, ret); - hbitmap_set(job->copy_bitmap, start / job->cluster_size, - nr_clusters); + hbitmap_set(job->copy_bitmap, start, job->cluster_size * nr_clusters); return ret; } @@ -202,7 +202,7 @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job, cow_request_begin(&cow_request, job, start, end); while (start < end) { - if (!hbitmap_get(job->copy_bitmap, start / job->cluster_size)) { + if (!hbitmap_get(job->copy_bitmap, start)) { trace_backup_do_cow_skip(job, start); start += job->cluster_size; continue; /* already copied */ @@ -298,12 +298,16 @@ static void backup_clean(Job *job) assert(s->target); blk_unref(s->target); s->target = NULL; + + if (s->copy_bitmap) { + hbitmap_free(s->copy_bitmap); + s->copy_bitmap = NULL; + } } void backup_do_checkpoint(BlockJob *job, Error **errp) { BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common); - int64_t len; assert(block_job_driver(job) == &backup_job_driver); @@ -313,8 +317,7 @@ void backup_do_checkpoint(BlockJob *job, Error **errp) return; } - len = DIV_ROUND_UP(backup_job->len, backup_job->cluster_size); - hbitmap_set(backup_job->copy_bitmap, 0, len); + hbitmap_set(backup_job->copy_bitmap, 0, backup_job->len); } static void backup_drain(BlockJob *job) @@ -365,20 +368,44 @@ static bool coroutine_fn yield_and_check(BackupBlockJob *job) return false; } -static int coroutine_fn backup_run_incremental(BackupBlockJob *job) +static bool bdrv_is_unallocated_range(BlockDriverState *bs, + int64_t offset, int64_t bytes) +{ + int64_t end = offset + bytes; + + while (offset < end && !bdrv_is_allocated(bs, offset, bytes, &bytes)) { + if (bytes == 0) { + return true; + } + offset += bytes; + bytes = end - offset; + } + + return offset >= end; +} + +static int coroutine_fn backup_loop(BackupBlockJob *job) { int ret; bool error_is_read; - int64_t cluster; + int64_t offset; HBitmapIter hbi; + BlockDriverState *bs = blk_bs(job->common.blk); hbitmap_iter_init(&hbi, job->copy_bitmap, 0); - while ((cluster = hbitmap_iter_next(&hbi)) != -1) { + while ((offset = hbitmap_iter_next(&hbi)) != -1) { + if (job->sync_mode == MIRROR_SYNC_MODE_TOP && + bdrv_is_unallocated_range(bs, offset, job->cluster_size)) + { + hbitmap_reset(job->copy_bitmap, offset, job->cluster_size); + continue; + } + do { if (yield_and_check(job)) { return 0; } - ret = backup_do_cow(job, cluster * job->cluster_size, + ret = backup_do_cow(job, offset, job->cluster_size, &error_is_read, false); if (ret < 0 && backup_error_action(job, error_is_read, -ret) == BLOCK_ERROR_ACTION_REPORT) @@ -394,66 +421,43 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job) /* init copy_bitmap from sync_bitmap */ static void backup_incremental_init_copy_bitmap(BackupBlockJob *job) { - BdrvDirtyBitmapIter *dbi; - int64_t offset; - int64_t end = DIV_ROUND_UP(bdrv_dirty_bitmap_size(job->sync_bitmap), - job->cluster_size); + uint64_t offset = 0; + uint64_t bytes = job->len; - dbi = bdrv_dirty_iter_new(job->sync_bitmap); - while ((offset = bdrv_dirty_iter_next(dbi)) != -1) { - int64_t cluster = offset / job->cluster_size; - int64_t next_cluster; - - offset += bdrv_dirty_bitmap_granularity(job->sync_bitmap); - if (offset >= bdrv_dirty_bitmap_size(job->sync_bitmap)) { - hbitmap_set(job->copy_bitmap, cluster, end - cluster); - break; - } + while (bdrv_dirty_bitmap_next_dirty_area(job->sync_bitmap, + &offset, &bytes)) + { + hbitmap_set(job->copy_bitmap, offset, bytes); - offset = bdrv_dirty_bitmap_next_zero(job->sync_bitmap, offset, - UINT64_MAX); - if (offset == -1) { - hbitmap_set(job->copy_bitmap, cluster, end - cluster); + offset += bytes; + if (offset >= job->len) { break; } - - next_cluster = DIV_ROUND_UP(offset, job->cluster_size); - hbitmap_set(job->copy_bitmap, cluster, next_cluster - cluster); - if (next_cluster >= end) { - break; - } - - bdrv_set_dirty_iter(dbi, next_cluster * job->cluster_size); + bytes = job->len - offset; } /* TODO job_progress_set_remaining() would make more sense */ job_progress_update(&job->common.job, - job->len - hbitmap_count(job->copy_bitmap) * job->cluster_size); - - bdrv_dirty_iter_free(dbi); + job->len - hbitmap_count(job->copy_bitmap)); } static int coroutine_fn backup_run(Job *job, Error **errp) { BackupBlockJob *s = container_of(job, BackupBlockJob, common.job); BlockDriverState *bs = blk_bs(s->common.blk); - int64_t offset, nb_clusters; int ret = 0; QLIST_INIT(&s->inflight_reqs); qemu_co_rwlock_init(&s->flush_rwlock); - nb_clusters = DIV_ROUND_UP(s->len, s->cluster_size); job_progress_set_remaining(job, s->len); - s->copy_bitmap = hbitmap_alloc(nb_clusters, 0); if (s->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) { backup_incremental_init_copy_bitmap(s); } else { - hbitmap_set(s->copy_bitmap, 0, nb_clusters); + hbitmap_set(s->copy_bitmap, 0, s->len); } - s->before_write.notify = backup_before_write_notify; bdrv_add_before_write_notifier(bs, &s->before_write); @@ -465,68 +469,8 @@ static int coroutine_fn backup_run(Job *job, Error **errp) * notify callback service CoW requests. */ job_yield(job); } - } else if (s->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) { - ret = backup_run_incremental(s); } else { - /* Both FULL and TOP SYNC_MODE's require copying.. */ - for (offset = 0; offset < s->len; - offset += s->cluster_size) { - bool error_is_read; - int alloced = 0; - - if (yield_and_check(s)) { - break; - } - - if (s->sync_mode == MIRROR_SYNC_MODE_TOP) { - int i; - int64_t n; - - /* Check to see if these blocks are already in the - * backing file. */ - - for (i = 0; i < s->cluster_size;) { - /* bdrv_is_allocated() only returns true/false based - * on the first set of sectors it comes across that - * are are all in the same state. - * For that reason we must verify each sector in the - * backup cluster length. We end up copying more than - * needed but at some point that is always the case. */ - alloced = - bdrv_is_allocated(bs, offset + i, - s->cluster_size - i, &n); - i += n; - - if (alloced || n == 0) { - break; - } - } - - /* If the above loop never found any sectors that are in - * the topmost image, skip this backup. */ - if (alloced == 0) { - continue; - } - } - /* FULL sync mode we copy the whole drive. */ - if (alloced < 0) { - ret = alloced; - } else { - ret = backup_do_cow(s, offset, s->cluster_size, - &error_is_read, false); - } - if (ret < 0) { - /* Depending on error action, fail now or retry cluster */ - BlockErrorAction action = - backup_error_action(s, error_is_read, -ret); - if (action == BLOCK_ERROR_ACTION_REPORT) { - break; - } else { - offset -= s->cluster_size; - continue; - } - } - } + ret = backup_loop(s); } notifier_with_return_remove(&s->before_write); @@ -534,7 +478,6 @@ static int coroutine_fn backup_run(Job *job, Error **errp) /* wait until pending backup_do_cow() calls have completed */ qemu_co_rwlock_wrlock(&s->flush_rwlock); qemu_co_rwlock_unlock(&s->flush_rwlock); - hbitmap_free(s->copy_bitmap); return ret; } @@ -554,6 +497,42 @@ static const BlockJobDriver backup_job_driver = { .drain = backup_drain, }; +static int64_t backup_calculate_cluster_size(BlockDriverState *target, + Error **errp) +{ + int ret; + BlockDriverInfo bdi; + + /* + * If there is no backing file on the target, we cannot rely on COW if our + * backup cluster size is smaller than the target cluster size. Even for + * targets with a backing file, try to avoid COW if possible. + */ + ret = bdrv_get_info(target, &bdi); + if (ret == -ENOTSUP && !target->backing) { + /* Cluster size is not defined */ + warn_report("The target block device doesn't provide " + "information about the block size and it doesn't have a " + "backing file. The default block size of %u bytes is " + "used. If the actual block size of the target exceeds " + "this default, the backup may be unusable", + BACKUP_CLUSTER_SIZE_DEFAULT); + return BACKUP_CLUSTER_SIZE_DEFAULT; + } else if (ret < 0 && !target->backing) { + error_setg_errno(errp, -ret, + "Couldn't determine the cluster size of the target image, " + "which has no backing file"); + error_append_hint(errp, + "Aborting, since this may create an unusable destination image\n"); + return ret; + } else if (ret < 0 && target->backing) { + /* Not fatal; just trudge on ahead. */ + return BACKUP_CLUSTER_SIZE_DEFAULT; + } + + return MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size); +} + BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, BlockDriverState *target, int64_t speed, MirrorSyncMode sync_mode, BdrvDirtyBitmap *sync_bitmap, @@ -565,9 +544,10 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, JobTxn *txn, Error **errp) { int64_t len; - BlockDriverInfo bdi; BackupBlockJob *job = NULL; int ret; + int64_t cluster_size; + HBitmap *copy_bitmap = NULL; assert(bs); assert(target); @@ -629,6 +609,13 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, goto error; } + cluster_size = backup_calculate_cluster_size(target, errp); + if (cluster_size < 0) { + goto error; + } + + copy_bitmap = hbitmap_alloc(len, ctz32(cluster_size)); + /* job->len is fixed, so we can't allow resize */ job = block_job_create(job_id, &backup_job_driver, txn, bs, BLK_PERM_CONSISTENT_READ, @@ -640,7 +627,8 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, } /* The target must match the source in size, so no resize here either */ - job->target = blk_new(BLK_PERM_WRITE, + job->target = blk_new(job->common.job.aio_context, + BLK_PERM_WRITE, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED | BLK_PERM_GRAPH_MOD); ret = blk_insert_bs(job->target, target, errp); @@ -657,33 +645,9 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, /* Detect image-fleecing (and similar) schemes */ job->serialize_target_writes = bdrv_chain_contains(target, bs); - - /* If there is no backing file on the target, we cannot rely on COW if our - * backup cluster size is smaller than the target cluster size. Even for - * targets with a backing file, try to avoid COW if possible. */ - ret = bdrv_get_info(target, &bdi); - if (ret == -ENOTSUP && !target->backing) { - /* Cluster size is not defined */ - warn_report("The target block device doesn't provide " - "information about the block size and it doesn't have a " - "backing file. The default block size of %u bytes is " - "used. If the actual block size of the target exceeds " - "this default, the backup may be unusable", - BACKUP_CLUSTER_SIZE_DEFAULT); - job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT; - } else if (ret < 0 && !target->backing) { - error_setg_errno(errp, -ret, - "Couldn't determine the cluster size of the target image, " - "which has no backing file"); - error_append_hint(errp, - "Aborting, since this may create an unusable destination image\n"); - goto error; - } else if (ret < 0 && target->backing) { - /* Not fatal; just trudge on ahead. */ - job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT; - } else { - job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size); - } + job->cluster_size = cluster_size; + job->copy_bitmap = copy_bitmap; + copy_bitmap = NULL; job->use_copy_range = true; job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk), blk_get_max_transfer(job->target)); @@ -699,6 +663,10 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, return &job->common; error: + if (copy_bitmap) { + assert(!job || !job->copy_bitmap); + hbitmap_free(copy_bitmap); + } if (sync_bitmap) { bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL); } |