]> Git Repo - qemu.git/blobdiff - blockdev.c
blockdev: Refuse to drive_del something added with blockdev-add
[qemu.git] / blockdev.c
index 69b7c2a8c5867d87ad1b99abf9a298d95ce1eda0..b361fbb964dc84996cbec98cb0a462d98ea4f3e9 100644 (file)
@@ -39,6 +39,7 @@
 #include "qapi/qmp/types.h"
 #include "qapi-visit.h"
 #include "qapi/qmp-output-visitor.h"
+#include "qapi/util.h"
 #include "sysemu/sysemu.h"
 #include "block/block_int.h"
 #include "qmp-commands.h"
@@ -274,25 +275,6 @@ static int parse_block_error_action(const char *buf, bool is_read, Error **errp)
     }
 }
 
-static inline int parse_enum_option(const char *lookup[], const char *buf,
-                                    int max, int def, Error **errp)
-{
-    int i;
-
-    if (!buf) {
-        return def;
-    }
-
-    for (i = 0; i < max; i++) {
-        if (!strcmp(buf, lookup[i])) {
-            return i;
-        }
-    }
-
-    error_setg(errp, "invalid parameter value: %s", buf);
-    return def;
-}
-
 static bool check_throttle_config(ThrottleConfig *cfg, Error **errp)
 {
     if (throttle_conflicting(cfg)) {
@@ -456,11 +438,11 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts,
     }
 
     detect_zeroes =
-        parse_enum_option(BlockdevDetectZeroesOptions_lookup,
-                          qemu_opt_get(opts, "detect-zeroes"),
-                          BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX,
-                          BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
-                          &error);
+        qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
+                        qemu_opt_get(opts, "detect-zeroes"),
+                        BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX,
+                        BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
+                        &error);
     if (error) {
         error_propagate(errp, error);
         goto early_err;
@@ -1094,7 +1076,7 @@ SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
         return NULL;
     }
 
-    info = g_malloc0(sizeof(SnapshotInfo));
+    info = g_new0(SnapshotInfo, 1);
     info->id = g_strdup(sn.id_str);
     info->name = g_strdup(sn.name);
     info->date_nsec = sn.date_nsec;
@@ -1757,6 +1739,8 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     const char *id = qdict_get_str(qdict, "id");
     BlockDriverState *bs;
+    DriveInfo *dinfo;
+    AioContext *aio_context;
     Error *local_err = NULL;
 
     bs = bdrv_find(id);
@@ -1764,9 +1748,21 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
         error_report("Device '%s' not found", id);
         return -1;
     }
+
+    dinfo = drive_get_by_blockdev(bs);
+    if (dinfo && !dinfo->enable_auto_del) {
+        error_report("Deleting device added with blockdev-add"
+                     " is not supported");
+        return -1;
+    }
+
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+
     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, &local_err)) {
         error_report("%s", error_get_pretty(local_err));
         error_free(local_err);
+        aio_context_release(aio_context);
         return -1;
     }
 
@@ -1787,9 +1783,10 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
         bdrv_set_on_error(bs, BLOCKDEV_ON_ERROR_REPORT,
                           BLOCKDEV_ON_ERROR_REPORT);
     } else {
-        drive_del(drive_get_by_blockdev(bs));
+        drive_del(dinfo);
     }
 
+    aio_context_release(aio_context);
     return 0;
 }
 
@@ -1799,6 +1796,7 @@ void qmp_block_resize(bool has_device, const char *device,
 {
     Error *local_err = NULL;
     BlockDriverState *bs;
+    AioContext *aio_context;
     int ret;
 
     bs = bdrv_lookup_bs(has_device ? device : NULL,
@@ -1809,19 +1807,22 @@ void qmp_block_resize(bool has_device, const char *device,
         return;
     }
 
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+
     if (!bdrv_is_first_non_filter(bs)) {
         error_set(errp, QERR_FEATURE_DISABLED, "resize");
-        return;
+        goto out;
     }
 
     if (size < 0) {
         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
-        return;
+        goto out;
     }
 
     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
         error_set(errp, QERR_DEVICE_IN_USE, device);
-        return;
+        goto out;
     }
 
     /* complete all in-flight operations before resizing the device */
@@ -1847,6 +1848,9 @@ void qmp_block_resize(bool has_device, const char *device,
         error_setg_errno(errp, -ret, "Could not resize");
         break;
     }
+
+out:
+    aio_context_release(aio_context);
 }
 
 static void block_job_cb(void *opaque, int ret)
@@ -1871,14 +1875,17 @@ static void block_job_cb(void *opaque, int ret)
     bdrv_put_ref_bh_schedule(bs);
 }
 
-void qmp_block_stream(const char *device, bool has_base,
-                      const char *base, bool has_speed, int64_t speed,
+void qmp_block_stream(const char *device,
+                      bool has_base, const char *base,
+                      bool has_backing_file, const char *backing_file,
+                      bool has_speed, int64_t speed,
                       bool has_on_error, BlockdevOnError on_error,
                       Error **errp)
 {
     BlockDriverState *bs;
     BlockDriverState *base_bs = NULL;
     Error *local_err = NULL;
+    const char *base_name = NULL;
 
     if (!has_on_error) {
         on_error = BLOCKDEV_ON_ERROR_REPORT;
@@ -1894,15 +1901,27 @@ void qmp_block_stream(const char *device, bool has_base,
         return;
     }
 
-    if (base) {
+    if (has_base) {
         base_bs = bdrv_find_backing_image(bs, base);
         if (base_bs == NULL) {
             error_set(errp, QERR_BASE_NOT_FOUND, base);
             return;
         }
+        base_name = base;
     }
 
-    stream_start(bs, base_bs, base, has_speed ? speed : 0,
+    /* if we are streaming the entire chain, the result will have no backing
+     * file, and specifying one is therefore an error */
+    if (base_bs == NULL && has_backing_file) {
+        error_setg(errp, "backing file specified, but streaming the "
+                         "entire chain");
+        return;
+    }
+
+    /* backing_file string overrides base bs filename */
+    base_name = has_backing_file ? backing_file : base_name;
+
+    stream_start(bs, base_bs, base_name, has_speed ? speed : 0,
                  on_error, block_job_cb, bs, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
@@ -1913,7 +1932,9 @@ void qmp_block_stream(const char *device, bool has_base,
 }
 
 void qmp_block_commit(const char *device,
-                      bool has_base, const char *base, const char *top,
+                      bool has_base, const char *base,
+                      bool has_top, const char *top,
+                      bool has_backing_file, const char *backing_file,
                       bool has_speed, int64_t speed,
                       Error **errp)
 {
@@ -1932,6 +1953,11 @@ void qmp_block_commit(const char *device,
     /* drain all i/o before commits */
     bdrv_drain_all();
 
+    /* Important Note:
+     *  libvirt relies on the DeviceNotFound error class in order to probe for
+     *  live commit feature versions; for this to work, we must make sure to
+     *  perform the device lookup before any generic errors that may occur in a
+     *  scenario in which all optional arguments are omitted. */
     bs = bdrv_find(device);
     if (!bs) {
         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
@@ -1945,7 +1971,7 @@ void qmp_block_commit(const char *device,
     /* default top_bs is the active layer */
     top_bs = bs;
 
-    if (top) {
+    if (has_top && top) {
         if (strcmp(bs->filename, top) != 0) {
             top_bs = bdrv_find_backing_image(bs, top);
         }
@@ -1967,12 +1993,23 @@ void qmp_block_commit(const char *device,
         return;
     }
 
+    /* Do not allow attempts to commit an image into itself */
+    if (top_bs == base_bs) {
+        error_setg(errp, "cannot commit an image into itself");
+        return;
+    }
+
     if (top_bs == bs) {
+        if (has_backing_file) {
+            error_setg(errp, "'backing-file' specified,"
+                             " but 'top' is the active layer");
+            return;
+        }
         commit_active_start(bs, base_bs, speed, on_error, block_job_cb,
                             bs, &local_err);
     } else {
         commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs,
-                    &local_err);
+                     has_backing_file ? backing_file : NULL, &local_err);
     }
     if (local_err != NULL) {
         error_propagate(errp, local_err);
@@ -2139,11 +2176,12 @@ void qmp_drive_mirror(const char *device, const char *target,
     }
 
     if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64)) {
-        error_set(errp, QERR_INVALID_PARAMETER, device);
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
+                  "a value in range [512B, 64MB]");
         return;
     }
     if (granularity & (granularity - 1)) {
-        error_set(errp, QERR_INVALID_PARAMETER, device);
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "granularity", "power of 2");
         return;
     }
 
@@ -2355,6 +2393,85 @@ void qmp_block_job_complete(const char *device, Error **errp)
     block_job_complete(job, errp);
 }
 
+void qmp_change_backing_file(const char *device,
+                             const char *image_node_name,
+                             const char *backing_file,
+                             Error **errp)
+{
+    BlockDriverState *bs = NULL;
+    BlockDriverState *image_bs = NULL;
+    Error *local_err = NULL;
+    bool ro;
+    int open_flags;
+    int ret;
+
+    /* find the top layer BDS of the chain */
+    bs = bdrv_find(device);
+    if (!bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        return;
+    }
+
+    image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    if (!image_bs) {
+        error_setg(errp, "image file not found");
+        return;
+    }
+
+    if (bdrv_find_base(image_bs) == image_bs) {
+        error_setg(errp, "not allowing backing file change on an image "
+                         "without a backing file");
+        return;
+    }
+
+    /* even though we are not necessarily operating on bs, we need it to
+     * determine if block ops are currently prohibited on the chain */
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
+        return;
+    }
+
+    /* final sanity check */
+    if (!bdrv_chain_contains(bs, image_bs)) {
+        error_setg(errp, "'%s' and image file are not in the same chain",
+                   device);
+        return;
+    }
+
+    /* if not r/w, reopen to make r/w */
+    open_flags = image_bs->open_flags;
+    ro = bdrv_is_read_only(image_bs);
+
+    if (ro) {
+        bdrv_reopen(image_bs, open_flags | BDRV_O_RDWR, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
+
+    ret = bdrv_change_backing_file(image_bs, backing_file,
+                               image_bs->drv ? image_bs->drv->format_name : "");
+
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Could not change backing file to '%s'",
+                         backing_file);
+        /* don't exit here, so we can try to restore open flags if
+         * appropriate */
+    }
+
+    if (ro) {
+        bdrv_reopen(image_bs, open_flags, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err); /* will preserve prior errp */
+        }
+    }
+}
+
 void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
 {
     QmpOutputVisitor *ov = qmp_output_visitor_new();
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