block: Add options QDict to bdrv_open() prototype

It doesn't do anything yet except storing the options QDict in the
BlockDriverState.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

block.c

@@ -788,7 +788,8 @@ int bdrv_open_backing_file(BlockDriverState *bs)
     /* backing files always opened read-only */
     back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT);
 
-    ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
+    ret = bdrv_open(bs->backing_hd, backing_filename, NULL,
+                    back_flags, back_drv);
     if (ret < 0) {
         bdrv_delete(bs->backing_hd);
         bs->backing_hd = NULL;
@@ -800,15 +801,28 @@ int bdrv_open_backing_file(BlockDriverState *bs)
 
 /*
  * Opens a disk image (raw, qcow2, vmdk, ...)
+ *
+ * options is a QDict of options to pass to the block drivers, or NULL for an
+ * empty set of options. The reference to the QDict belongs to the block layer
+ * after the call (even on failure), so if the caller intends to reuse the
+ * dictionary, it needs to use QINCREF() before calling bdrv_open.
  */
-int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
-              BlockDriver *drv)
+int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
+              int flags, BlockDriver *drv)
 {
     int ret;
     /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
     char tmp_filename[PATH_MAX + 1];
     BlockDriverState *file = NULL;
 
+    /* NULL means an empty set of options */
+    if (options == NULL) {
+        options = qdict_new();
+    }
+
+    bs->options = options;
+
+    /* For snapshot=on, create a temporary qcow2 overlay */
     if (flags & BDRV_O_SNAPSHOT) {
         BlockDriverState *bs1;
         int64_t total_size;
@@ -822,10 +836,10 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
 
         /* if there is a backing file, use it */
         bs1 = bdrv_new("");
-        ret = bdrv_open(bs1, filename, 0, drv);
+        ret = bdrv_open(bs1, filename, NULL, 0, drv);
         if (ret < 0) {
             bdrv_delete(bs1);
-            return ret;
+            goto fail;
         }
         total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
 
@@ -836,15 +850,17 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
 
         ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename));
         if (ret < 0) {
-            return ret;
+            goto fail;
         }
 
         /* Real path is meaningless for protocols */
-        if (is_protocol)
+        if (is_protocol) {
             snprintf(backing_filename, sizeof(backing_filename),
                      "%s", filename);
-        else if (!realpath(filename, backing_filename))
-            return -errno;
+        } else if (!realpath(filename, backing_filename)) {
+            ret = -errno;
+            goto fail;
+        }
 
         bdrv_qcow2 = bdrv_find_format("qcow2");
         options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
@@ -859,7 +875,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
         free_option_parameters(options);
         if (ret < 0) {
-            return ret;
+            goto fail;
         }
 
         filename = tmp_filename;
@@ -874,7 +890,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
 
     ret = bdrv_file_open(&file, filename, bdrv_open_flags(bs, flags));
     if (ret < 0) {
-        return ret;
+        goto fail;
     }
 
     /* Find the right image format driver */
@@ -924,6 +940,10 @@ unlink_and_fail:
     if (bs->is_temporary) {
         unlink(filename);
     }
+fail:
+    QDECREF(bs->options);
+    bs->options = NULL;
+
     return ret;
 }
 
@@ -1193,6 +1213,8 @@ void bdrv_close(BlockDriverState *bs)
         bs->valid_key = 0;
         bs->sg = 0;
         bs->growable = 0;
+        QDECREF(bs->options);
+        bs->options = NULL;
 
         if (bs->file != NULL) {
             bdrv_delete(bs->file);
@@ -4594,7 +4616,8 @@ void bdrv_img_create(const char *filename, const char *fmt,
 
             bs = bdrv_new("");
 
-            ret = bdrv_open(bs, backing_file->value.s, back_flags, backing_drv);
+            ret = bdrv_open(bs, backing_file->value.s, NULL, back_flags,
+                            backing_drv);
             if (ret < 0) {
                 error_setg_errno(errp, -ret, "Could not open '%s'",
                                  backing_file->value.s);

block/blkverify.c

@@ -98,7 +98,7 @@ static int blkverify_open(BlockDriverState *bs, const char *filename, int flags)
 
     /* Open the test file */
     s->test_file = bdrv_new("");
-    ret = bdrv_open(s->test_file, filename, flags, NULL);
+    ret = bdrv_open(s->test_file, filename, NULL, flags, NULL);
     if (ret < 0) {
         bdrv_delete(s->test_file);
         s->test_file = NULL;

block/qcow2.c

@@ -1265,7 +1265,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
      */
     BlockDriver* drv = bdrv_find_format("qcow2");
     assert(drv != NULL);
-    ret = bdrv_open(bs, filename,
+    ret = bdrv_open(bs, filename, NULL,
         BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv);
     if (ret < 0) {
         goto out;

block/vmdk.c

@@ -1527,7 +1527,7 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options)
     if (backing_file) {
         char parent_filename[PATH_MAX];
         BlockDriverState *bs = bdrv_new("");
-        ret = bdrv_open(bs, backing_file, 0, NULL);
+        ret = bdrv_open(bs, backing_file, NULL, 0, NULL);
         if (ret != 0) {
             bdrv_delete(bs);
             return ret;

block/vvfat.c

@@ -2830,7 +2830,7 @@ static int enable_write_target(BDRVVVFATState *s)
         return -1;
     }
 
-    ret = bdrv_open(s->qcow, s->qcow_filename,
+    ret = bdrv_open(s->qcow, s->qcow_filename, NULL,
             BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, bdrv_qcow);
     if (ret < 0) {
 	return ret;

blockdev.c

@@ -635,7 +635,7 @@ DriveInfo *drive_init(QemuOpts *opts, BlockInterfaceType block_default_type)
         error_report("warning: disabling copy_on_read on readonly drive");
     }
 
-    ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
+    ret = bdrv_open(dinfo->bdrv, file, NULL, bdrv_flags, drv);
     if (ret < 0) {
         if (ret == -EMEDIUMTYPE) {
             error_report("could not open disk image %s: not in %s format",
@@ -820,7 +820,9 @@ void qmp_transaction(BlockdevActionList *dev_list, Error **errp)
 
         /* We will manually add the backing_hd field to the bs later */
         states->new_bs = bdrv_new("");
-        ret = bdrv_open(states->new_bs, new_image_file,
+        /* TODO Inherit bs->options or only take explicit options with an
+         * extended QMP command? */
+        ret = bdrv_open(states->new_bs, new_image_file, NULL,
                         flags | BDRV_O_NO_BACKING, drv);
         if (ret != 0) {
             error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file);
@@ -921,7 +923,7 @@ static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
                                     int bdrv_flags, BlockDriver *drv,
                                     const char *password, Error **errp)
 {
-    if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
+    if (bdrv_open(bs, filename, NULL, bdrv_flags, drv) < 0) {
         error_set(errp, QERR_OPEN_FILE_FAILED, filename);
         return;
     }
@@ -1330,7 +1332,7 @@ void qmp_drive_mirror(const char *device, const char *target,
      * file.
      */
     target_bs = bdrv_new("");
-    ret = bdrv_open(target_bs, target, flags | BDRV_O_NO_BACKING, drv);
+    ret = bdrv_open(target_bs, target, NULL, flags | BDRV_O_NO_BACKING, drv);
 
     if (ret < 0) {
         bdrv_delete(target_bs);

hw/xen_disk.c

@@ -763,7 +763,7 @@ static int blk_init(struct XenDevice *xendev)
         xen_be_printf(&blkdev->xendev, 2, "create new bdrv (xenbus setup)\n");
         blkdev->bs = bdrv_new(blkdev->dev);
         if (blkdev->bs) {
-            if (bdrv_open(blkdev->bs, blkdev->filename, qflags,
+            if (bdrv_open(blkdev->bs, blkdev->filename, NULL, qflags,
                         bdrv_find_whitelisted_format(blkdev->fileproto)) != 0) {
                 bdrv_delete(blkdev->bs);
                 blkdev->bs = NULL;

include/block/block.h

@@ -137,8 +137,8 @@ int bdrv_parse_cache_flags(const char *mode, int *flags);
 int bdrv_parse_discard_flags(const char *mode, int *flags);
 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags);
 int bdrv_open_backing_file(BlockDriverState *bs);
-int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
-              BlockDriver *drv);
+int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
+              int flags, BlockDriver *drv);
 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
                                     BlockDriverState *bs, int flags);
 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);

include/block/block_int.h

@@ -286,6 +286,7 @@ struct BlockDriverState {
     /* long-running background operation */
     BlockJob *job;
 
+    QDict *options;
 };
 
 int get_tmp_filename(char *filename, int size);

qemu-img.c

@@ -276,7 +276,7 @@ static BlockDriverState *bdrv_new_open(const char *filename,
         drv = NULL;
     }
 
-    ret = bdrv_open(bs, filename, flags, drv);
+    ret = bdrv_open(bs, filename, NULL, flags, drv);
     if (ret < 0) {
         error_report("Could not open '%s': %s", filename, strerror(-ret));
         goto fail;
@@ -2156,7 +2156,7 @@ static int img_rebase(int argc, char **argv)
 
         bs_old_backing = bdrv_new("old_backing");
         bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
-        ret = bdrv_open(bs_old_backing, backing_name, BDRV_O_FLAGS,
+        ret = bdrv_open(bs_old_backing, backing_name, NULL, BDRV_O_FLAGS,
                         old_backing_drv);
         if (ret) {
             error_report("Could not open old backing file '%s'", backing_name);
@@ -2164,7 +2164,7 @@ static int img_rebase(int argc, char **argv)
         }
         if (out_baseimg[0]) {
             bs_new_backing = bdrv_new("new_backing");
-            ret = bdrv_open(bs_new_backing, out_baseimg, BDRV_O_FLAGS,
+            ret = bdrv_open(bs_new_backing, out_baseimg, NULL, BDRV_O_FLAGS,
                         new_backing_drv);
             if (ret) {
                 error_report("Could not open new backing file '%s'",

qemu-io.c

@@ -1773,7 +1773,7 @@ static int openfile(char *name, int flags, int growable)
     } else {
         bs = bdrv_new("hda");
 
-        if (bdrv_open(bs, name, flags, NULL) < 0) {
+        if (bdrv_open(bs, name, NULL, flags, NULL) < 0) {
             fprintf(stderr, "%s: can't open device %s\n", progname, name);
             bdrv_delete(bs);
             bs = NULL;

qemu-nbd.c

@@ -557,7 +557,7 @@ int main(int argc, char **argv)
 
     bs = bdrv_new("hda");
     srcpath = argv[optind];
-    if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) {
+    if ((ret = bdrv_open(bs, srcpath, NULL, flags, NULL)) < 0) {
         errno = -ret;
         err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
     }