On BlockBackend destruction, unref its BlockDriverState. Replaces the
callers' unrefs.
This turns the pointer from BlockBackend to BlockDriverState into a
strong reference, managed with bdrv_ref() / bdrv_unref(). The
back-pointer remains weak.
Signed-off-by: Markus Armbruster <arm...@redhat.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
Reviewed-by: Kevin Wolf <kw...@redhat.com>
---
block/block-backend.c | 6 ++----
blockdev.c | 7 +------
hw/block/xen_disk.c | 6 +++---
qemu-img.c | 35 +----------------------------------
qemu-io.c | 5 -----
qemu-nbd.c | 1 -
6 files changed, 7 insertions(+), 53 deletions(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index d4bdd48..6236b5b 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -54,8 +54,6 @@ BlockBackend *blk_new(const char *name, Error **errp)
/*
* Create a new BlockBackend with a new BlockDriverState attached.
- * Both have a reference count of one. Caller owns *both* references.
- * TODO Let caller own only the BlockBackend reference
* Otherwise just like blk_new(), which see.
*/
BlockBackend *blk_new_with_bs(const char *name, Error **errp)
@@ -83,7 +81,9 @@ static void blk_delete(BlockBackend *blk)
{
assert(!blk->refcnt);
if (blk->bs) {
+ assert(blk->bs->blk == blk);
blk->bs->blk = NULL;
+ bdrv_unref(blk->bs);
blk->bs = NULL;
}
/* Avoid double-remove after blk_hide_on_behalf_of_do_drive_del() */
@@ -119,8 +119,6 @@ void blk_ref(BlockBackend *blk)
* Decrement @blk's reference count.
* If this drops it to zero, destroy @blk.
* For convenience, do nothing if @blk is null.
- * Does *not* touch the attached BlockDriverState's reference count.
- * TODO Decrement it!
*/
void blk_unref(BlockBackend *blk)
{
diff --git a/blockdev.c b/blockdev.c
index a00461d..63f797b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -278,10 +278,7 @@ static void bdrv_format_print(void *opaque, const char
*name)
void drive_del(DriveInfo *dinfo)
{
- BlockBackend *blk = dinfo->bdrv->blk;
-
- bdrv_unref(dinfo->bdrv);
- blk_unref(blk);
+ blk_unref(dinfo->bdrv->blk);
}
typedef struct {
@@ -583,7 +580,6 @@ static BlockBackend *blockdev_init(const char *file, QDict
*bs_opts,
return blk;
err:
- bdrv_unref(bs);
blk_unref(blk);
early_err:
qemu_opts_del(opts);
@@ -2608,7 +2604,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Error
**errp)
}
if (bdrv_key_required(blk_bs(blk))) {
- bdrv_unref(blk_bs(blk));
blk_unref(blk);
error_setg(errp, "blockdev-add doesn't support encrypted devices");
goto fail;
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
index 0022083..feb227f 100644
--- a/hw/block/xen_disk.c
+++ b/hw/block/xen_disk.c
@@ -872,7 +872,6 @@ static int blk_connect(struct XenDevice *xendev)
xen_be_printf(&blkdev->xendev, 0, "error: %s\n",
error_get_pretty(local_err));
error_free(local_err);
- bdrv_unref(blkdev->bs);
blk_unref(blk);
blkdev->bs = NULL;
return -1;
@@ -888,7 +887,9 @@ static int blk_connect(struct XenDevice *xendev)
}
/* blkdev->bs is not create by us, we get a reference
* so we can bdrv_unref() unconditionally */
- bdrv_ref(blkdev->bs);
+ /* Except we don't bdrv_unref() anymore, we blk_unref().
+ * Conditionally, because we can't easily blk_ref() here.
+ * TODO Clean this up! */
}
bdrv_attach_dev_nofail(blkdev->bs, blkdev);
blkdev->file_size = bdrv_getlength(blkdev->bs);
@@ -988,7 +989,6 @@ static void blk_disconnect(struct XenDevice *xendev)
if (blkdev->bs) {
bdrv_detach_dev(blkdev->bs, blkdev);
- bdrv_unref(blkdev->bs);
if (!blkdev->dinfo) {
blk_unref(blk_by_name(blkdev->dev));
}
diff --git a/qemu-img.c b/qemu-img.c
index 5548637..09e7e72 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -329,7 +329,6 @@ static BlockBackend *img_open(const char *id, const char
*filename,
}
return blk;
fail:
- bdrv_unref(bs);
blk_unref(blk);
return NULL;
}
@@ -712,9 +711,7 @@ static int img_check(int argc, char **argv)
fail:
qapi_free_ImageCheck(check);
- bdrv_unref(bs);
blk_unref(blk);
-
return ret;
}
@@ -786,7 +783,6 @@ static int img_commit(int argc, char **argv)
break;
}
- bdrv_unref(bs);
blk_unref(blk);
if (ret) {
return 1;
@@ -1196,10 +1192,8 @@ static int img_compare(int argc, char **argv)
out:
qemu_vfree(buf1);
qemu_vfree(buf2);
- bdrv_unref(bs2);
blk_unref(blk2);
out2:
- bdrv_unref(bs1);
blk_unref(blk1);
out3:
qemu_progress_end();
@@ -1754,18 +1748,8 @@ out:
qemu_opts_free(create_opts);
qemu_vfree(buf);
qemu_opts_del(sn_opts);
- if (out_bs) {
- bdrv_unref(out_bs);
- }
blk_unref(out_blk);
- if (bs) {
- for (bs_i = 0; bs_i < bs_n; bs_i++) {
- if (bs[bs_i]) {
- bdrv_unref(bs[bs_i]);
- }
- }
- g_free(bs);
- }
+ g_free(bs);
if (blk) {
for (bs_i = 0; bs_i < bs_n; bs_i++) {
blk_unref(blk[bs_i]);
@@ -1903,7 +1887,6 @@ static ImageInfoList *collect_image_info_list(const char
*filename,
if (err) {
error_report("%s", error_get_pretty(err));
error_free(err);
- bdrv_unref(bs);
blk_unref(blk);
goto err;
}
@@ -1913,7 +1896,6 @@ static ImageInfoList *collect_image_info_list(const char
*filename,
*last = elem;
last = &elem->next;
- bdrv_unref(bs);
blk_unref(blk);
filename = fmt = NULL;
@@ -2202,7 +2184,6 @@ static int img_map(int argc, char **argv)
dump_map_entry(output_format, &curr, NULL);
out:
- bdrv_unref(bs);
blk_unref(blk);
return ret < 0;
}
@@ -2327,7 +2308,6 @@ static int img_snapshot(int argc, char **argv)
}
/* Cleanup */
- bdrv_unref(bs);
blk_unref(blk);
if (ret) {
return 1;
@@ -2647,17 +2627,10 @@ out:
qemu_progress_end();
/* Cleanup */
if (!unsafe) {
- if (bs_old_backing != NULL) {
- bdrv_unref(bs_old_backing);
- }
blk_unref(blk_old_backing);
- if (bs_new_backing != NULL) {
- bdrv_unref(bs_new_backing);
- }
blk_unref(blk_new_backing);
}
- bdrv_unref(bs);
blk_unref(blk);
if (ret) {
return 1;
@@ -2783,9 +2756,6 @@ static int img_resize(int argc, char **argv)
break;
}
out:
- if (bs) {
- bdrv_unref(bs);
- }
blk_unref(blk);
if (ret) {
return 1;
@@ -2897,9 +2867,6 @@ static int img_amend(int argc, char **argv)
}
out:
- if (bs) {
- bdrv_unref(bs);
- }
blk_unref(blk);
qemu_opts_del(opts);
qemu_opts_free(create_opts);
diff --git a/qemu-io.c b/qemu-io.c
index 8380734..60f84dd 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -38,7 +38,6 @@ static ReadLineState *readline_state;
static int close_f(BlockDriverState *bs, int argc, char **argv)
{
- bdrv_unref(bs);
blk_unref(qemuio_blk);
qemuio_bs = NULL;
qemuio_blk = NULL;
@@ -74,7 +73,6 @@ static int openfile(char *name, int flags, int growable,
QDict *opts)
name ? " device " : "", name ?: "",
error_get_pretty(local_err));
error_free(local_err);
- bdrv_unref(qemuio_bs);
blk_unref(qemuio_blk);
qemuio_bs = NULL;
qemuio_blk = NULL;
@@ -488,9 +486,6 @@ int main(int argc, char **argv)
*/
bdrv_drain_all();
- if (qemuio_bs) {
- bdrv_unref(qemuio_bs);
- }
blk_unref(qemuio_blk);
g_free(readline_state);
return 0;
diff --git a/qemu-nbd.c b/qemu-nbd.c
index f741973..5cd6c6d 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -775,7 +775,6 @@ int main(int argc, char **argv)
}
} while (state != TERMINATED);
- bdrv_unref(bs);
blk_unref(blk);
if (sockpath) {
unlink(sockpath);
--
1.9.3
