]> Git Repo - qemu.git/blobdiff - block/backup.c
block/backup: centralize copy_bitmap initialization
[qemu.git] / block / backup.c
index 00f4f8af5320594eb97b00abb0f1dc5496274c70..305f9b3468b07f053eb061b7d07c227e8a97775d 100644 (file)
@@ -38,9 +38,12 @@ typedef struct CowRequest {
 typedef struct BackupBlockJob {
     BlockJob common;
     BlockBackend *target;
-    /* bitmap for sync=incremental */
+
     BdrvDirtyBitmap *sync_bitmap;
+    BdrvDirtyBitmap *copy_bitmap;
+
     MirrorSyncMode sync_mode;
+    BitmapSyncMode bitmap_mode;
     BlockdevOnError on_source_error;
     BlockdevOnError on_target_error;
     CoRwlock flush_rwlock;
@@ -51,7 +54,6 @@ typedef struct BackupBlockJob {
     NotifierWithReturn before_write;
     QLIST_HEAD(, CowRequest) inflight_reqs;
 
-    HBitmap *copy_bitmap;
     bool use_copy_range;
     int64_t copy_range_size;
 
@@ -113,7 +115,7 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
     int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0;
 
     assert(QEMU_IS_ALIGNED(start, job->cluster_size));
-    hbitmap_reset(job->copy_bitmap, start, job->cluster_size);
+    bdrv_reset_dirty_bitmap(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);
@@ -146,7 +148,7 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
 
     return nbytes;
 fail:
-    hbitmap_set(job->copy_bitmap, start, job->cluster_size);
+    bdrv_set_dirty_bitmap(job->copy_bitmap, start, job->cluster_size);
     return ret;
 
 }
@@ -169,12 +171,14 @@ static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
     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);
+    bdrv_reset_dirty_bitmap(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);
+        bdrv_set_dirty_bitmap(job->copy_bitmap, start,
+                              job->cluster_size * nr_clusters);
         return ret;
     }
 
@@ -202,22 +206,32 @@ 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)) {
+        int64_t dirty_end;
+
+        if (!bdrv_dirty_bitmap_get(job->copy_bitmap, start)) {
             trace_backup_do_cow_skip(job, start);
             start += job->cluster_size;
             continue; /* already copied */
         }
 
+        dirty_end = bdrv_dirty_bitmap_next_zero(job->copy_bitmap, start,
+                                                (end - start));
+        if (dirty_end < 0) {
+            dirty_end = end;
+        }
+
         trace_backup_do_cow_process(job, start);
 
         if (job->use_copy_range) {
-            ret = backup_cow_with_offload(job, start, end, is_write_notifier);
+            ret = backup_cow_with_offload(job, start, dirty_end,
+                                          is_write_notifier);
             if (ret < 0) {
                 job->use_copy_range = false;
             }
         }
         if (!job->use_copy_range) {
-            ret = backup_cow_with_bounce_buffer(job, start, end, is_write_notifier,
+            ret = backup_cow_with_bounce_buffer(job, start, dirty_end,
+                                                is_write_notifier,
                                                 error_is_read, &bounce_buffer);
         }
         if (ret < 0) {
@@ -264,15 +278,29 @@ static void backup_cleanup_sync_bitmap(BackupBlockJob *job, int ret)
 {
     BdrvDirtyBitmap *bm;
     BlockDriverState *bs = blk_bs(job->common.blk);
+    bool sync = (((ret == 0) || (job->bitmap_mode == BITMAP_SYNC_MODE_ALWAYS)) \
+                 && (job->bitmap_mode != BITMAP_SYNC_MODE_NEVER));
 
-    if (ret < 0) {
-        /* Merge the successor back into the parent, delete nothing. */
-        bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
-        assert(bm);
-    } else {
-        /* Everything is fine, delete this bitmap and install the backup. */
+    if (sync) {
+        /*
+         * We succeeded, or we always intended to sync the bitmap.
+         * Delete this bitmap and install the child.
+         */
         bm = bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL);
-        assert(bm);
+    } else {
+        /*
+         * We failed, or we never intended to sync the bitmap anyway.
+         * Merge the successor back into the parent, keeping all data.
+         */
+        bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
+    }
+
+    assert(bm);
+
+    if (ret < 0 && job->bitmap_mode == BITMAP_SYNC_MODE_ALWAYS) {
+        /* If we failed and synced, merge in the bits we didn't copy: */
+        bdrv_dirty_bitmap_merge_internal(bm, job->copy_bitmap,
+                                         NULL, true);
     }
 }
 
@@ -295,14 +323,16 @@ static void backup_abort(Job *job)
 static void backup_clean(Job *job)
 {
     BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
-    assert(s->target);
-    blk_unref(s->target);
-    s->target = NULL;
+    BlockDriverState *bs = blk_bs(s->common.blk);
 
     if (s->copy_bitmap) {
-        hbitmap_free(s->copy_bitmap);
+        bdrv_release_dirty_bitmap(bs, s->copy_bitmap);
         s->copy_bitmap = NULL;
     }
+
+    assert(s->target);
+    blk_unref(s->target);
+    s->target = NULL;
 }
 
 void backup_do_checkpoint(BlockJob *job, Error **errp)
@@ -317,7 +347,7 @@ void backup_do_checkpoint(BlockJob *job, Error **errp)
         return;
     }
 
-    hbitmap_set(backup_job->copy_bitmap, 0, backup_job->len);
+    bdrv_set_dirty_bitmap(backup_job->copy_bitmap, 0, backup_job->len);
 }
 
 static void backup_drain(BlockJob *job)
@@ -386,59 +416,57 @@ static bool bdrv_is_unallocated_range(BlockDriverState *bs,
 
 static int coroutine_fn backup_loop(BackupBlockJob *job)
 {
-    int ret;
     bool error_is_read;
     int64_t offset;
-    HBitmapIter hbi;
+    BdrvDirtyBitmapIter *bdbi;
     BlockDriverState *bs = blk_bs(job->common.blk);
+    int ret = 0;
 
-    hbitmap_iter_init(&hbi, job->copy_bitmap, 0);
-    while ((offset = hbitmap_iter_next(&hbi)) != -1) {
+    bdbi = bdrv_dirty_iter_new(job->copy_bitmap);
+    while ((offset = bdrv_dirty_iter_next(bdbi)) != -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);
+            bdrv_reset_dirty_bitmap(job->copy_bitmap, offset,
+                                    job->cluster_size);
             continue;
         }
 
         do {
             if (yield_and_check(job)) {
-                return 0;
+                goto out;
             }
             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)
             {
-                return ret;
+                goto out;
             }
         } while (ret < 0);
     }
 
-    return 0;
+ out:
+    bdrv_dirty_iter_free(bdbi);
+    return ret;
 }
 
-/* init copy_bitmap from sync_bitmap */
-static void backup_incremental_init_copy_bitmap(BackupBlockJob *job)
+static void backup_init_copy_bitmap(BackupBlockJob *job)
 {
-    uint64_t offset = 0;
-    uint64_t bytes = job->len;
-
-    while (bdrv_dirty_bitmap_next_dirty_area(job->sync_bitmap,
-                                             &offset, &bytes))
-    {
-        hbitmap_set(job->copy_bitmap, offset, bytes);
-
-        offset += bytes;
-        if (offset >= job->len) {
-            break;
-        }
-        bytes = job->len - offset;
+    bool ret;
+    uint64_t estimate;
+
+    if (job->sync_mode == MIRROR_SYNC_MODE_BITMAP) {
+        ret = bdrv_dirty_bitmap_merge_internal(job->copy_bitmap,
+                                               job->sync_bitmap,
+                                               NULL, true);
+        assert(ret);
+    } else {
+        bdrv_set_dirty_bitmap(job->copy_bitmap, 0, job->len);
     }
 
-    /* TODO job_progress_set_remaining() would make more sense */
-    job_progress_update(&job->common.job,
-        job->len - hbitmap_count(job->copy_bitmap));
+    estimate = bdrv_get_dirty_count(job->copy_bitmap);
+    job_progress_set_remaining(&job->common.job, estimate);
 }
 
 static int coroutine_fn backup_run(Job *job, Error **errp)
@@ -450,13 +478,7 @@ static int coroutine_fn backup_run(Job *job, Error **errp)
     QLIST_INIT(&s->inflight_reqs);
     qemu_co_rwlock_init(&s->flush_rwlock);
 
-    job_progress_set_remaining(job, s->len);
-
-    if (s->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
-        backup_incremental_init_copy_bitmap(s);
-    } else {
-        hbitmap_set(s->copy_bitmap, 0, s->len);
-    }
+    backup_init_copy_bitmap(s);
 
     s->before_write.notify = backup_before_write_notify;
     bdrv_add_before_write_notifier(bs, &s->before_write);
@@ -536,6 +558,7 @@ static int64_t backup_calculate_cluster_size(BlockDriverState *target,
 BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
                   BlockDriverState *target, int64_t speed,
                   MirrorSyncMode sync_mode, BdrvDirtyBitmap *sync_bitmap,
+                  BitmapSyncMode bitmap_mode,
                   bool compress,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
@@ -547,11 +570,15 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
     BackupBlockJob *job = NULL;
     int ret;
     int64_t cluster_size;
-    HBitmap *copy_bitmap = NULL;
+    BdrvDirtyBitmap *copy_bitmap = NULL;
 
     assert(bs);
     assert(target);
 
+    /* QMP interface protects us from these cases */
+    assert(sync_mode != MIRROR_SYNC_MODE_INCREMENTAL);
+    assert(sync_bitmap || sync_mode != MIRROR_SYNC_MODE_BITMAP);
+
     if (bs == target) {
         error_setg(errp, "Source and target cannot be the same");
         return NULL;
@@ -583,10 +610,10 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
         return NULL;
     }
 
-    if (sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
-        if (!sync_bitmap) {
-            error_setg(errp, "must provide a valid bitmap name for "
-                             "\"incremental\" sync mode");
+    if (sync_mode == MIRROR_SYNC_MODE_BITMAP) {
+        /* If we need to write to this bitmap, check that we can: */
+        if (bitmap_mode != BITMAP_SYNC_MODE_NEVER &&
+            bdrv_dirty_bitmap_check(sync_bitmap, BDRV_BITMAP_DEFAULT, errp)) {
             return NULL;
         }
 
@@ -596,8 +623,8 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
         }
     } else if (sync_bitmap) {
         error_setg(errp,
-                   "a sync_bitmap was provided to backup_run, "
-                   "but received an incompatible sync_mode (%s)",
+                   "a bitmap was given to backup_job_create, "
+                   "but it received an incompatible sync_mode (%s)",
                    MirrorSyncMode_str(sync_mode));
         return NULL;
     }
@@ -614,7 +641,11 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
         goto error;
     }
 
-    copy_bitmap = hbitmap_alloc(len, ctz32(cluster_size));
+    copy_bitmap = bdrv_create_dirty_bitmap(bs, cluster_size, NULL, errp);
+    if (!copy_bitmap) {
+        goto error;
+    }
+    bdrv_disable_dirty_bitmap(copy_bitmap);
 
     /* job->len is fixed, so we can't allow resize */
     job = block_job_create(job_id, &backup_job_driver, txn, bs,
@@ -627,19 +658,21 @@ 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);
     if (ret < 0) {
         goto error;
     }
+    blk_set_disable_request_queuing(job->target, true);
 
     job->on_source_error = on_source_error;
     job->on_target_error = on_target_error;
     job->sync_mode = sync_mode;
-    job->sync_bitmap = sync_mode == MIRROR_SYNC_MODE_INCREMENTAL ?
-                       sync_bitmap : NULL;
+    job->sync_bitmap = sync_bitmap;
+    job->bitmap_mode = bitmap_mode;
     job->compress = compress;
 
     /* Detect image-fleecing (and similar) schemes */
@@ -647,7 +680,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
     job->cluster_size = cluster_size;
     job->copy_bitmap = copy_bitmap;
     copy_bitmap = NULL;
-    job->use_copy_range = true;
+    job->use_copy_range = !compress; /* compression isn't supported for it */
     job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk),
                                         blk_get_max_transfer(job->target));
     job->copy_range_size = MAX(job->cluster_size,
@@ -664,7 +697,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
  error:
     if (copy_bitmap) {
         assert(!job || !job->copy_bitmap);
-        hbitmap_free(copy_bitmap);
+        bdrv_release_dirty_bitmap(bs, copy_bitmap);
     }
     if (sync_bitmap) {
         bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL);
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