]> Git Repo - qemu.git/blobdiff - block/commit.c
qcow2: Let qcow2_create() handle protocol layer
[qemu.git] / block / commit.c
index a3028b20f3f67b4d6e617391e512dd7f6b874fc7..1943c9c3e166194ab0f5100d4d53db147cf522fe 100644 (file)
@@ -36,37 +36,34 @@ enum {
 typedef struct CommitBlockJob {
     BlockJob common;
     RateLimit limit;
-    BlockDriverState *active;
     BlockDriverState *commit_top_bs;
     BlockBackend *top;
     BlockBackend *base;
     BlockdevOnError on_error;
     int base_flags;
-    int orig_overlay_flags;
     char *backing_file_str;
 } CommitBlockJob;
 
 static int coroutine_fn commit_populate(BlockBackend *bs, BlockBackend *base,
-                                        int64_t sector_num, int nb_sectors,
+                                        int64_t offset, uint64_t bytes,
                                         void *buf)
 {
     int ret = 0;
     QEMUIOVector qiov;
     struct iovec iov = {
         .iov_base = buf,
-        .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
+        .iov_len = bytes,
     };
 
+    assert(bytes < SIZE_MAX);
     qemu_iovec_init_external(&qiov, &iov, 1);
 
-    ret = blk_co_preadv(bs, sector_num * BDRV_SECTOR_SIZE,
-                        qiov.size, &qiov, 0);
+    ret = blk_co_preadv(bs, offset, qiov.size, &qiov, 0);
     if (ret < 0) {
         return ret;
     }
 
-    ret = blk_co_pwritev(base, sector_num * BDRV_SECTOR_SIZE,
-                         qiov.size, &qiov, 0);
+    ret = blk_co_pwritev(base, offset, qiov.size, &qiov, 0);
     if (ret < 0) {
         return ret;
     }
@@ -82,22 +79,25 @@ static void commit_complete(BlockJob *job, void *opaque)
 {
     CommitBlockJob *s = container_of(job, CommitBlockJob, common);
     CommitCompleteData *data = opaque;
-    BlockDriverState *active = s->active;
     BlockDriverState *top = blk_bs(s->top);
     BlockDriverState *base = blk_bs(s->base);
-    BlockDriverState *overlay_bs = bdrv_find_overlay(active, s->commit_top_bs);
+    BlockDriverState *commit_top_bs = s->commit_top_bs;
     int ret = data->ret;
     bool remove_commit_top_bs = false;
 
+    /* Make sure commit_top_bs and top stay around until bdrv_replace_node() */
+    bdrv_ref(top);
+    bdrv_ref(commit_top_bs);
+
     /* Remove base node parent that still uses BLK_PERM_WRITE/RESIZE before
      * the normal backing chain can be restored. */
     blk_unref(s->base);
 
     if (!block_job_is_cancelled(&s->common) && ret == 0) {
         /* success */
-        ret = bdrv_drop_intermediate(active, s->commit_top_bs, base,
+        ret = bdrv_drop_intermediate(s->commit_top_bs, base,
                                      s->backing_file_str);
-    } else if (overlay_bs) {
+    } else {
         /* XXX Can (or should) we somehow keep 'consistent read' blocked even
          * after the failed/cancelled commit job is gone? If we already wrote
          * something to base, the intermediate images aren't valid any more. */
@@ -110,11 +110,15 @@ static void commit_complete(BlockJob *job, void *opaque)
     if (s->base_flags != bdrv_get_flags(base)) {
         bdrv_reopen(base, s->base_flags, NULL);
     }
-    if (overlay_bs && s->orig_overlay_flags != bdrv_get_flags(overlay_bs)) {
-        bdrv_reopen(overlay_bs, s->orig_overlay_flags, NULL);
-    }
     g_free(s->backing_file_str);
     blk_unref(s->top);
+
+    /* If there is more than one reference to the job (e.g. if called from
+     * block_job_finish_sync()), block_job_completed() won't free it and
+     * therefore the blockers on the intermediate nodes remain. This would
+     * cause bdrv_set_backing_hd() to fail. */
+    block_job_remove_all_bdrv(job);
+
     block_job_completed(&s->common, ret);
     g_free(data);
 
@@ -122,25 +126,30 @@ static void commit_complete(BlockJob *job, void *opaque)
      * filter driver from the backing chain. Do this as the final step so that
      * the 'consistent read' permission can be granted.  */
     if (remove_commit_top_bs) {
-        bdrv_set_backing_hd(overlay_bs, top, &error_abort);
+        bdrv_child_try_set_perm(commit_top_bs->backing, 0, BLK_PERM_ALL,
+                                &error_abort);
+        bdrv_replace_node(commit_top_bs, backing_bs(commit_top_bs),
+                          &error_abort);
     }
+
+    bdrv_unref(commit_top_bs);
+    bdrv_unref(top);
 }
 
 static void coroutine_fn commit_run(void *opaque)
 {
     CommitBlockJob *s = opaque;
     CommitCompleteData *data;
-    int64_t sector_num, end;
+    int64_t offset;
     uint64_t delay_ns = 0;
     int ret = 0;
-    int n = 0;
+    int64_t n = 0; /* bytes */
     void *buf = NULL;
     int bytes_written = 0;
     int64_t base_len;
 
     ret = s->common.len = blk_getlength(s->top);
 
-
     if (s->common.len < 0) {
         goto out;
     }
@@ -151,35 +160,32 @@ static void coroutine_fn commit_run(void *opaque)
     }
 
     if (base_len < s->common.len) {
-        ret = blk_truncate(s->base, s->common.len, NULL);
+        ret = blk_truncate(s->base, s->common.len, PREALLOC_MODE_OFF, NULL);
         if (ret) {
             goto out;
         }
     }
 
-    end = s->common.len >> BDRV_SECTOR_BITS;
     buf = blk_blockalign(s->top, COMMIT_BUFFER_SIZE);
 
-    for (sector_num = 0; sector_num < end; sector_num += n) {
+    for (offset = 0; offset < s->common.len; offset += n) {
         bool copy;
 
         /* Note that even when no rate limit is applied we need to yield
          * with no pending I/O here so that bdrv_drain_all() returns.
          */
-        block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
+        block_job_sleep_ns(&s->common, delay_ns);
         if (block_job_is_cancelled(&s->common)) {
             break;
         }
         /* Copy if allocated above the base */
         ret = bdrv_is_allocated_above(blk_bs(s->top), blk_bs(s->base),
-                                      sector_num,
-                                      COMMIT_BUFFER_SIZE / BDRV_SECTOR_SIZE,
-                                      &n);
+                                      offset, COMMIT_BUFFER_SIZE, &n);
         copy = (ret == 1);
-        trace_commit_one_iteration(s, sector_num, n, ret);
+        trace_commit_one_iteration(s, offset, n, ret);
         if (copy) {
-            ret = commit_populate(s->top, s->base, sector_num, n, buf);
-            bytes_written += n * BDRV_SECTOR_SIZE;
+            ret = commit_populate(s->top, s->base, offset, n, buf);
+            bytes_written += n;
         }
         if (ret < 0) {
             BlockErrorAction action =
@@ -192,7 +198,7 @@ static void coroutine_fn commit_run(void *opaque)
             }
         }
         /* Publish progress */
-        s->common.offset += n * BDRV_SECTOR_SIZE;
+        s->common.offset += n;
 
         if (copy && s->common.speed) {
             delay_ns = ratelimit_calculate_delay(&s->limit, n);
@@ -217,7 +223,7 @@ static void commit_set_speed(BlockJob *job, int64_t speed, Error **errp)
         error_setg(errp, QERR_INVALID_PARAMETER, "speed");
         return;
     }
-    ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME);
+    ratelimit_set_speed(&s->limit, speed, SLICE_TIME);
 }
 
 static const BlockJobDriver commit_job_driver = {
@@ -233,16 +239,6 @@ static int coroutine_fn bdrv_commit_top_preadv(BlockDriverState *bs,
     return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
 }
 
-static int64_t coroutine_fn bdrv_commit_top_get_block_status(
-    BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
-    BlockDriverState **file)
-{
-    *pnum = nb_sectors;
-    *file = bs->backing->bs;
-    return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
-           (sector_num << BDRV_SECTOR_BITS);
-}
-
 static void bdrv_commit_top_refresh_filename(BlockDriverState *bs, QDict *opts)
 {
     bdrv_refresh_filename(bs->backing->bs);
@@ -256,6 +252,7 @@ static void bdrv_commit_top_close(BlockDriverState *bs)
 
 static void bdrv_commit_top_child_perm(BlockDriverState *bs, BdrvChild *c,
                                        const BdrvChildRole *role,
+                                       BlockReopenQueue *reopen_queue,
                                        uint64_t perm, uint64_t shared,
                                        uint64_t *nperm, uint64_t *nshared)
 {
@@ -268,7 +265,7 @@ static void bdrv_commit_top_child_perm(BlockDriverState *bs, BdrvChild *c,
 static BlockDriver bdrv_commit_top = {
     .format_name                = "commit_top",
     .bdrv_co_preadv             = bdrv_commit_top_preadv,
-    .bdrv_co_get_block_status   = bdrv_commit_top_get_block_status,
+    .bdrv_co_block_status       = bdrv_co_block_status_from_backing,
     .bdrv_refresh_filename      = bdrv_commit_top_refresh_filename,
     .bdrv_close                 = bdrv_commit_top_close,
     .bdrv_child_perm            = bdrv_commit_top_child_perm,
@@ -280,11 +277,8 @@ void commit_start(const char *job_id, BlockDriverState *bs,
                   const char *filter_node_name, Error **errp)
 {
     CommitBlockJob *s;
-    BlockReopenQueue *reopen_queue = NULL;
-    int orig_overlay_flags;
     int orig_base_flags;
     BlockDriverState *iter;
-    BlockDriverState *overlay_bs;
     BlockDriverState *commit_top_bs = NULL;
     Error *local_err = NULL;
     int ret;
@@ -295,33 +289,16 @@ void commit_start(const char *job_id, BlockDriverState *bs,
         return;
     }
 
-    overlay_bs = bdrv_find_overlay(bs, top);
-
-    if (overlay_bs == NULL) {
-        error_setg(errp, "Could not find overlay image for %s:", top->filename);
-        return;
-    }
-
     s = block_job_create(job_id, &commit_job_driver, bs, 0, BLK_PERM_ALL,
                          speed, BLOCK_JOB_DEFAULT, NULL, NULL, errp);
     if (!s) {
         return;
     }
 
-    orig_base_flags    = bdrv_get_flags(base);
-    orig_overlay_flags = bdrv_get_flags(overlay_bs);
-
-    /* convert base & overlay_bs to r/w, if necessary */
+    /* convert base to r/w, if necessary */
+    orig_base_flags = bdrv_get_flags(base);
     if (!(orig_base_flags & BDRV_O_RDWR)) {
-        reopen_queue = bdrv_reopen_queue(reopen_queue, base, NULL,
-                                         orig_base_flags | BDRV_O_RDWR);
-    }
-    if (!(orig_overlay_flags & BDRV_O_RDWR)) {
-        reopen_queue = bdrv_reopen_queue(reopen_queue, overlay_bs, NULL,
-                                         orig_overlay_flags | BDRV_O_RDWR);
-    }
-    if (reopen_queue) {
-        bdrv_reopen_multiple(bdrv_get_aio_context(bs), reopen_queue, &local_err);
+        bdrv_reopen(base, orig_base_flags | BDRV_O_RDWR, &local_err);
         if (local_err != NULL) {
             error_propagate(errp, local_err);
             goto fail;
@@ -335,6 +312,9 @@ void commit_start(const char *job_id, BlockDriverState *bs,
     if (commit_top_bs == NULL) {
         goto fail;
     }
+    if (!filter_node_name) {
+        commit_top_bs->implicit = true;
+    }
     commit_top_bs->total_sectors = top->total_sectors;
     bdrv_set_aio_context(commit_top_bs, bdrv_get_aio_context(top));
 
@@ -345,7 +325,7 @@ void commit_start(const char *job_id, BlockDriverState *bs,
         error_propagate(errp, local_err);
         goto fail;
     }
-    bdrv_set_backing_hd(overlay_bs, commit_top_bs, &local_err);
+    bdrv_replace_node(top, commit_top_bs, &local_err);
     if (local_err) {
         bdrv_unref(commit_top_bs);
         commit_top_bs = NULL;
@@ -377,14 +357,6 @@ void commit_start(const char *job_id, BlockDriverState *bs,
         goto fail;
     }
 
-    /* overlay_bs must be blocked because it needs to be modified to
-     * update the backing image string. */
-    ret = block_job_add_bdrv(&s->common, "overlay of top", overlay_bs,
-                             BLK_PERM_GRAPH_MOD, BLK_PERM_ALL, errp);
-    if (ret < 0) {
-        goto fail;
-    }
-
     s->base = blk_new(BLK_PERM_CONSISTENT_READ
                       | BLK_PERM_WRITE
                       | BLK_PERM_RESIZE,
@@ -403,13 +375,8 @@ void commit_start(const char *job_id, BlockDriverState *bs,
         goto fail;
     }
 
-    s->active = bs;
-
-    s->base_flags          = orig_base_flags;
-    s->orig_overlay_flags  = orig_overlay_flags;
-
+    s->base_flags = orig_base_flags;
     s->backing_file_str = g_strdup(backing_file_str);
-
     s->on_error = on_error;
 
     trace_commit_start(bs, base, top, s);
@@ -424,13 +391,13 @@ fail:
         blk_unref(s->top);
     }
     if (commit_top_bs) {
-        bdrv_set_backing_hd(overlay_bs, top, &error_abort);
+        bdrv_replace_node(commit_top_bs, top, &error_abort);
     }
     block_job_early_fail(&s->common);
 }
 
 
-#define COMMIT_BUF_SECTORS 2048
+#define COMMIT_BUF_SIZE (2048 * BDRV_SECTOR_SIZE)
 
 /* commit COW file into the raw image */
 int bdrv_commit(BlockDriverState *bs)
@@ -439,8 +406,9 @@ int bdrv_commit(BlockDriverState *bs)
     BlockDriverState *backing_file_bs = NULL;
     BlockDriverState *commit_top_bs = NULL;
     BlockDriver *drv = bs->drv;
-    int64_t sector, total_sectors, length, backing_length;
-    int n, ro, open_flags;
+    int64_t offset, length, backing_length;
+    int ro, open_flags;
+    int64_t n;
     int ret = 0;
     uint8_t *buf = NULL;
     Error *local_err = NULL;
@@ -511,37 +479,33 @@ int bdrv_commit(BlockDriverState *bs)
      * grow the backing file image if possible.  If not possible,
      * we must return an error */
     if (length > backing_length) {
-        ret = blk_truncate(backing, length, &local_err);
+        ret = blk_truncate(backing, length, PREALLOC_MODE_OFF, &local_err);
         if (ret < 0) {
             error_report_err(local_err);
             goto ro_cleanup;
         }
     }
 
-    total_sectors = length >> BDRV_SECTOR_BITS;
-
     /* blk_try_blockalign() for src will choose an alignment that works for
      * backing as well, so no need to compare the alignment manually. */
-    buf = blk_try_blockalign(src, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
+    buf = blk_try_blockalign(src, COMMIT_BUF_SIZE);
     if (buf == NULL) {
         ret = -ENOMEM;
         goto ro_cleanup;
     }
 
-    for (sector = 0; sector < total_sectors; sector += n) {
-        ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n);
+    for (offset = 0; offset < length; offset += n) {
+        ret = bdrv_is_allocated(bs, offset, COMMIT_BUF_SIZE, &n);
         if (ret < 0) {
             goto ro_cleanup;
         }
         if (ret) {
-            ret = blk_pread(src, sector * BDRV_SECTOR_SIZE, buf,
-                            n * BDRV_SECTOR_SIZE);
+            ret = blk_pread(src, offset, buf, n);
             if (ret < 0) {
                 goto ro_cleanup;
             }
 
-            ret = blk_pwrite(backing, sector * BDRV_SECTOR_SIZE, buf,
-                             n * BDRV_SECTOR_SIZE, 0);
+            ret = blk_pwrite(backing, offset, buf, n, 0);
             if (ret < 0) {
                 goto ro_cleanup;
             }
This page took 0.036193 seconds and 4 git commands to generate.