]> Git Repo - qemu.git/blobdiff - block.c
block: Move op_blocker check from block_job_create to its caller
[qemu.git] / block.c
diff --git a/block.c b/block.c
index 4745712d22e571f0a59f4e7acf94938d2a418f21..64c48a54a16004f63d21cf73a2980e5f975a4191 100644 (file)
--- a/block.c
+++ b/block.c
@@ -335,6 +335,7 @@ void bdrv_register(BlockDriver *bdrv)
 BlockDriverState *bdrv_new(const char *device_name, Error **errp)
 {
     BlockDriverState *bs;
+    int i;
 
     if (bdrv_find(device_name)) {
         error_setg(errp, "Device with id '%s' already exists",
@@ -353,6 +354,9 @@ BlockDriverState *bdrv_new(const char *device_name, Error **errp)
     if (device_name[0] != '\0') {
         QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list);
     }
+    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+        QLIST_INIT(&bs->op_blockers[i]);
+    }
     bdrv_iostatus_disable(bs);
     notifier_list_init(&bs->close_notifiers);
     notifier_with_return_list_init(&bs->before_write_notifiers);
@@ -774,15 +778,54 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs)
     bs->copy_on_read--;
 }
 
+/*
+ * Returns the flags that a temporary snapshot should get, based on the
+ * originally requested flags (the originally requested image will have flags
+ * like a backing file)
+ */
+static int bdrv_temp_snapshot_flags(int flags)
+{
+    return (flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
+}
+
+/*
+ * Returns the flags that bs->file should get, based on the given flags for
+ * the parent BDS
+ */
+static int bdrv_inherited_flags(int flags)
+{
+    /* Enable protocol handling, disable format probing for bs->file */
+    flags |= BDRV_O_PROTOCOL;
+
+    /* Our block drivers take care to send flushes and respect unmap policy,
+     * so we can enable both unconditionally on lower layers. */
+    flags |= BDRV_O_CACHE_WB | BDRV_O_UNMAP;
+
+    /* Clear flags that only apply to the top layer */
+    flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ);
+
+    return flags;
+}
+
+/*
+ * Returns the flags that bs->backing_hd should get, based on the given flags
+ * for the parent BDS
+ */
+static int bdrv_backing_flags(int flags)
+{
+    /* backing files always opened read-only */
+    flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ);
+
+    /* snapshot=on is handled on the top layer */
+    flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY);
+
+    return flags;
+}
+
 static int bdrv_open_flags(BlockDriverState *bs, int flags)
 {
     int open_flags = flags | BDRV_O_CACHE_WB;
 
-    /* The backing file of a temporary snapshot is read-only */
-    if (flags & BDRV_O_SNAPSHOT) {
-        open_flags &= ~BDRV_O_RDWR;
-    }
-
     /*
      * Clear flags that are internal to the block layer before opening the
      * image.
@@ -792,7 +835,7 @@ static int bdrv_open_flags(BlockDriverState *bs, int flags)
     /*
      * Snapshots should be writable.
      */
-    if (bs->is_temporary) {
+    if (flags & BDRV_O_TEMPORARY) {
         open_flags |= BDRV_O_RDWR;
     }
 
@@ -951,13 +994,6 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     bdrv_refresh_limits(bs);
     assert(bdrv_opt_mem_align(bs) != 0);
     assert((bs->request_alignment != 0) || bs->sg);
-
-#ifndef _WIN32
-    if (bs->is_temporary) {
-        assert(bs->filename[0] != '\0');
-        unlink(bs->filename);
-    }
-#endif
     return 0;
 
 free_and_fail:
@@ -1069,7 +1105,7 @@ fail:
 int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
 {
     char *backing_filename = g_malloc0(PATH_MAX);
-    int back_flags, ret = 0;
+    int ret = 0;
     BlockDriver *back_drv = NULL;
     Error *local_err = NULL;
 
@@ -1097,14 +1133,10 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
         back_drv = bdrv_find_format(bs->backing_format);
     }
 
-    /* backing files always opened read-only */
-    back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT |
-                                    BDRV_O_COPY_ON_READ);
-
     assert(bs->backing_hd == NULL);
     ret = bdrv_open(&bs->backing_hd,
                     *backing_filename ? backing_filename : NULL, NULL, options,
-                    back_flags, back_drv, &local_err);
+                    bdrv_backing_flags(bs->open_flags), back_drv, &local_err);
     if (ret < 0) {
         bs->backing_hd = NULL;
         bs->open_flags |= BDRV_O_NO_BACKING;
@@ -1178,7 +1210,7 @@ done:
     return ret;
 }
 
-void bdrv_append_temp_snapshot(BlockDriverState *bs, Error **errp)
+void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp)
 {
     /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
     char *tmp_filename = g_malloc0(PATH_MAX + 1);
@@ -1232,10 +1264,9 @@ void bdrv_append_temp_snapshot(BlockDriverState *bs, Error **errp)
               qstring_from_str(tmp_filename));
 
     bs_snapshot = bdrv_new("", &error_abort);
-    bs_snapshot->is_temporary = 1;
 
     ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options,
-                    bs->open_flags & ~BDRV_O_SNAPSHOT, bdrv_qcow2, &local_err);
+                    flags, bdrv_qcow2, &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         goto out;
@@ -1247,6 +1278,33 @@ out:
     g_free(tmp_filename);
 }
 
+static QDict *parse_json_filename(const char *filename, Error **errp)
+{
+    QObject *options_obj;
+    QDict *options;
+    int ret;
+
+    ret = strstart(filename, "json:", &filename);
+    assert(ret);
+
+    options_obj = qobject_from_json(filename);
+    if (!options_obj) {
+        error_setg(errp, "Could not parse the JSON options");
+        return NULL;
+    }
+
+    if (qobject_type(options_obj) != QTYPE_QDICT) {
+        qobject_decref(options_obj);
+        error_setg(errp, "Invalid JSON object given");
+        return NULL;
+    }
+
+    options = qobject_to_qdict(options_obj);
+    qdict_flatten(options);
+
+    return options;
+}
+
 /*
  * Opens a disk image (raw, qcow2, vmdk, ...)
  *
@@ -1270,6 +1328,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
     BlockDriverState *file = NULL, *bs;
     const char *drvname;
     Error *local_err = NULL;
+    int snapshot_flags = 0;
 
     assert(pbs);
 
@@ -1309,6 +1368,20 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
         options = qdict_new();
     }
 
+    if (filename && g_str_has_prefix(filename, "json:")) {
+        QDict *json_options = parse_json_filename(filename, &local_err);
+        if (local_err) {
+            ret = -EINVAL;
+            goto fail;
+        }
+
+        /* Options given in the filename have lower priority than options
+         * specified directly */
+        qdict_join(options, json_options, false);
+        QDECREF(json_options);
+        filename = NULL;
+    }
+
     bs->options = options;
     options = qdict_clone_shallow(options);
 
@@ -1330,13 +1403,17 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
     if (flags & BDRV_O_RDWR) {
         flags |= BDRV_O_ALLOW_RDWR;
     }
+    if (flags & BDRV_O_SNAPSHOT) {
+        snapshot_flags = bdrv_temp_snapshot_flags(flags);
+        flags = bdrv_backing_flags(flags);
+    }
 
     assert(file == NULL);
     ret = bdrv_open_image(&file, filename, options, "file",
-                          bdrv_open_flags(bs, flags | BDRV_O_UNMAP) |
-                          BDRV_O_PROTOCOL, true, &local_err);
+                          bdrv_inherited_flags(flags),
+                          true, &local_err);
     if (ret < 0) {
-        goto unlink_and_fail;
+        goto fail;
     }
 
     /* Find the right image format driver */
@@ -1347,7 +1424,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
         if (!drv) {
             error_setg(errp, "Invalid driver: '%s'", drvname);
             ret = -EINVAL;
-            goto unlink_and_fail;
+            goto fail;
         }
     }
 
@@ -1357,18 +1434,18 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
         } else {
             error_setg(errp, "Must specify either driver or file");
             ret = -EINVAL;
-            goto unlink_and_fail;
+            goto fail;
         }
     }
 
     if (!drv) {
-        goto unlink_and_fail;
+        goto fail;
     }
 
     /* Open the image */
     ret = bdrv_open_common(bs, file, options, flags, drv, &local_err);
     if (ret < 0) {
-        goto unlink_and_fail;
+        goto fail;
     }
 
     if (file && (bs->file != file)) {
@@ -1389,8 +1466,8 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
 
     /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
      * temporary snapshot afterwards. */
-    if (flags & BDRV_O_SNAPSHOT) {
-        bdrv_append_temp_snapshot(bs, &local_err);
+    if (snapshot_flags) {
+        bdrv_append_temp_snapshot(bs, snapshot_flags, &local_err);
         if (local_err) {
             error_propagate(errp, local_err);
             goto close_and_fail;
@@ -1430,14 +1507,10 @@ done:
     *pbs = bs;
     return 0;
 
-unlink_and_fail:
+fail:
     if (file != NULL) {
         bdrv_unref(file);
     }
-    if (bs->is_temporary) {
-        unlink(filename);
-    }
-fail:
     QDECREF(bs->options);
     QDECREF(options);
     bs->options = NULL;
@@ -1501,8 +1574,11 @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
         QSIMPLEQ_INIT(bs_queue);
     }
 
+    /* bdrv_open() masks this flag out */
+    flags &= ~BDRV_O_PROTOCOL;
+
     if (bs->file) {
-        bdrv_reopen_queue(bs_queue, bs->file, flags);
+        bdrv_reopen_queue(bs_queue, bs->file, bdrv_inherited_flags(flags));
     }
 
     bs_entry = g_new0(BlockReopenQueueEntry, 1);
@@ -1717,11 +1793,6 @@ void bdrv_close(BlockDriverState *bs)
         }
         bs->drv->bdrv_close(bs);
         g_free(bs->opaque);
-#ifdef _WIN32
-        if (bs->is_temporary) {
-            unlink(bs->filename);
-        }
-#endif
         bs->opaque = NULL;
         bs->drv = NULL;
         bs->copy_on_read = 0;
@@ -1845,7 +1916,6 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
                                      BlockDriverState *bs_src)
 {
     /* move some fields that need to stay attached to the device */
-    bs_dest->open_flags         = bs_src->open_flags;
 
     /* dev info */
     bs_dest->dev_ops            = bs_src->dev_ops;
@@ -1879,13 +1949,14 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
     bs_dest->refcnt             = bs_src->refcnt;
 
     /* job */
-    bs_dest->in_use             = bs_src->in_use;
     bs_dest->job                = bs_src->job;
 
     /* keep the same entry in bdrv_states */
     pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name),
             bs_src->device_name);
     bs_dest->device_list = bs_src->device_list;
+    memcpy(bs_dest->op_blockers, bs_src->op_blockers,
+           sizeof(bs_dest->op_blockers));
 }
 
 /*
@@ -1920,7 +1991,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
     assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
     assert(bs_new->job == NULL);
     assert(bs_new->dev == NULL);
-    assert(bs_new->in_use == 0);
+    assert(bdrv_op_blocker_is_empty(bs_new));
     assert(bs_new->io_limits_enabled == false);
     assert(!throttle_have_timer(&bs_new->throttle_state));
 
@@ -1939,7 +2010,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
     /* Check a few fields that should remain attached to the device */
     assert(bs_new->dev == NULL);
     assert(bs_new->job == NULL);
-    assert(bs_new->in_use == 0);
+    assert(bdrv_op_blocker_is_empty(bs_new));
     assert(bs_new->io_limits_enabled == false);
     assert(!throttle_have_timer(&bs_new->throttle_state));
 
@@ -1984,7 +2055,7 @@ static void bdrv_delete(BlockDriverState *bs)
 {
     assert(!bs->dev);
     assert(!bs->job);
-    assert(!bs->in_use);
+    assert(bdrv_op_blocker_is_empty(bs));
     assert(!bs->refcnt);
     assert(QLIST_EMPTY(&bs->dirty_bitmaps));
 
@@ -2166,7 +2237,8 @@ int bdrv_commit(BlockDriverState *bs)
         return -ENOTSUP;
     }
 
-    if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) {
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, NULL) ||
+        bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, NULL)) {
         return -EBUSY;
     }
 
@@ -3223,6 +3295,15 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
 
     ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
 
+    if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
+        !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes &&
+        qemu_iovec_is_zero(qiov)) {
+        flags |= BDRV_REQ_ZERO_WRITE;
+        if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
+            flags |= BDRV_REQ_MAY_UNMAP;
+        }
+    }
+
     if (ret < 0) {
         /* Do nothing, write notifier decided to fail this request */
     } else if (flags & BDRV_REQ_ZERO_WRITE) {
@@ -3419,8 +3500,9 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
         return -ENOTSUP;
     if (bs->read_only)
         return -EACCES;
-    if (bdrv_in_use(bs))
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
         return -EBUSY;
+    }
     ret = drv->bdrv_truncate(bs, offset);
     if (ret == 0) {
         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
@@ -3601,10 +3683,25 @@ void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
                          void *opaque)
 {
     BlockDriver *drv;
+    int count = 0;
+    const char **formats = NULL;
 
     QLIST_FOREACH(drv, &bdrv_drivers, list) {
-        it(opaque, drv->format_name);
+        if (drv->format_name) {
+            bool found = false;
+            int i = count;
+            while (formats && i && !found) {
+                found = !strcmp(formats[--i], drv->format_name);
+            }
+
+            if (!found) {
+                formats = g_realloc(formats, (count + 1) * sizeof(char *));
+                formats[count++] = drv->format_name;
+                it(opaque, drv->format_name);
+            }
+        }
     }
+    g_free(formats);
 }
 
 /* This function is to find block backend bs */
@@ -3824,7 +3921,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
 
     if (!bs->drv->bdrv_co_get_block_status) {
         *pnum = nb_sectors;
-        ret = BDRV_BLOCK_DATA;
+        ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
         if (bs->drv->protocol_name) {
             ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
         }
@@ -3843,6 +3940,10 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
                                      *pnum, pnum);
     }
 
+    if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
+        ret |= BDRV_BLOCK_ALLOCATED;
+    }
+
     if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
         if (bdrv_unallocated_blocks_are_zero(bs)) {
             ret |= BDRV_BLOCK_ZERO;
@@ -3919,9 +4020,7 @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
     if (ret < 0) {
         return ret;
     }
-    return
-        (ret & BDRV_BLOCK_DATA) ||
-        ((ret & BDRV_BLOCK_ZERO) && !bdrv_has_zero_init(bs));
+    return (ret & BDRV_BLOCK_ALLOCATED);
 }
 
 /*
@@ -5233,15 +5332,74 @@ void bdrv_unref(BlockDriverState *bs)
     }
 }
 
-void bdrv_set_in_use(BlockDriverState *bs, int in_use)
+struct BdrvOpBlocker {
+    Error *reason;
+    QLIST_ENTRY(BdrvOpBlocker) list;
+};
+
+bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
+{
+    BdrvOpBlocker *blocker;
+    assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
+    if (!QLIST_EMPTY(&bs->op_blockers[op])) {
+        blocker = QLIST_FIRST(&bs->op_blockers[op]);
+        if (errp) {
+            error_setg(errp, "Device '%s' is busy: %s",
+                       bs->device_name, error_get_pretty(blocker->reason));
+        }
+        return true;
+    }
+    return false;
+}
+
+void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
+{
+    BdrvOpBlocker *blocker;
+    assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
+
+    blocker = g_malloc0(sizeof(BdrvOpBlocker));
+    blocker->reason = reason;
+    QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
+}
+
+void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
 {
-    assert(bs->in_use != in_use);
-    bs->in_use = in_use;
+    BdrvOpBlocker *blocker, *next;
+    assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
+    QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
+        if (blocker->reason == reason) {
+            QLIST_REMOVE(blocker, list);
+            g_free(blocker);
+        }
+    }
 }
 
-int bdrv_in_use(BlockDriverState *bs)
+void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
 {
-    return bs->in_use;
+    int i;
+    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+        bdrv_op_block(bs, i, reason);
+    }
+}
+
+void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
+{
+    int i;
+    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+        bdrv_op_unblock(bs, i, reason);
+    }
+}
+
+bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
+{
+    int i;
+
+    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
+        if (!QLIST_EMPTY(&bs->op_blockers[i])) {
+            return false;
+        }
+    }
+    return true;
 }
 
 void bdrv_iostatus_enable(BlockDriverState *bs)
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