block: Eliminate BlockDriverState member device_name[]
device_name[] can become non-empty only in bdrv_new_root() and
bdrv_move_feature_fields(). The latter is used only to undo damage
done by bdrv_swap(). The former is called only by blk_new_with_bs().
Therefore, when a BlockDriverState's device_name[] is non-empty, then
it's been created with a BlockBackend, and vice versa. Furthermore,
blk_new_with_bs() keeps the two names equal.
Therefore, device_name[] is redundant. Eliminate it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index d13d29b..5c37970 100644
--- a/block.c
+++ b/block.c
@@ -28,6 +28,7 @@
#include "block/blockjob.h"
#include "qemu/module.h"
#include "qapi/qmp/qjson.h"
+#include "sysemu/block-backend.h"
#include "sysemu/sysemu.h"
#include "qemu/notify.h"
#include "block/coroutine.h"
@@ -360,9 +361,7 @@
bs = bdrv_new();
- pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list);
-
return bs;
}
@@ -1168,7 +1167,7 @@
} else if (backing_hd) {
error_setg(&bs->backing_blocker,
"device is used as backing hd of '%s'",
- bs->device_name);
+ bdrv_get_device_name(bs));
}
bs->backing_hd = backing_hd;
@@ -1542,7 +1541,7 @@
} else {
error_setg(errp, "Block format '%s' used by device '%s' doesn't "
"support the option '%s'", drv->format_name,
- bs->device_name, entry->key);
+ bdrv_get_device_name(bs), entry->key);
}
ret = -EINVAL;
@@ -1749,7 +1748,7 @@
if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) &&
reopen_state->flags & BDRV_O_RDWR) {
error_set(errp, QERR_DEVICE_IS_READ_ONLY,
- reopen_state->bs->device_name);
+ bdrv_get_device_name(reopen_state->bs));
goto error;
}
@@ -1776,7 +1775,7 @@
/* It is currently mandatory to have a bdrv_reopen_prepare()
* handler for each supported drv. */
error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
- drv->format_name, reopen_state->bs->device_name,
+ drv->format_name, bdrv_get_device_name(reopen_state->bs),
"reopening of file");
ret = -1;
goto error;
@@ -1964,10 +1963,17 @@
Also, NULL terminate the device_name to prevent double remove */
void bdrv_make_anon(BlockDriverState *bs)
{
- if (bs->device_name[0] != '\0') {
+ /*
+ * Take care to remove bs from bdrv_states only when it's actually
+ * in it. Note that bs->device_list.tqe_prev is initially null,
+ * and gets set to non-null by QTAILQ_INSERT_TAIL(). Establish
+ * the useful invariant "bs in bdrv_states iff bs->tqe_prev" by
+ * resetting it to null on remove.
+ */
+ if (bs->device_list.tqe_prev) {
QTAILQ_REMOVE(&bdrv_states, bs, device_list);
+ bs->device_list.tqe_prev = NULL;
}
- bs->device_name[0] = '\0';
if (bs->node_name[0] != '\0') {
QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
}
@@ -2021,8 +2027,6 @@
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;
bs_dest->blk = bs_src->blk;
@@ -2038,7 +2042,7 @@
* This will modify the BlockDriverState fields, and swap contents
* between bs_new and bs_old. Both bs_new and bs_old are modified.
*
- * bs_new must be nameless and not attached to a BlockBackend.
+ * bs_new must not be attached to a BlockBackend.
*
* This function does not create any image files.
*/
@@ -2057,8 +2061,7 @@
QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list);
}
- /* bs_new must be nameless and shouldn't have anything fancy enabled */
- assert(bs_new->device_name[0] == '\0');
+ /* bs_new must be unattached and shouldn't have anything fancy enabled */
assert(!bs_new->blk);
assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
assert(bs_new->job == NULL);
@@ -2075,8 +2078,7 @@
bdrv_move_feature_fields(bs_old, bs_new);
bdrv_move_feature_fields(bs_new, &tmp);
- /* bs_new must remain nameless and unattached */
- assert(bs_new->device_name[0] == '\0');
+ /* bs_new must remain unattached */
assert(!bs_new->blk);
/* Check a few fields that should remain attached to the device */
@@ -2104,7 +2106,7 @@
* This will modify the BlockDriverState fields, and swap contents
* between bs_new and bs_top. Both bs_new and bs_top are modified.
*
- * bs_new must be nameless and not attached to a BlockBackend.
+ * bs_new must not be attached to a BlockBackend.
*
* This function does not create any image files.
*/
@@ -3820,7 +3822,7 @@
BlockDriverState *bs;
QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
- if (!strcmp(name, bs->device_name)) {
+ if (!strcmp(name, bdrv_get_device_name(bs))) {
return bs;
}
}
@@ -3906,9 +3908,9 @@
return QTAILQ_NEXT(bs, device_list);
}
-const char *bdrv_get_device_name(BlockDriverState *bs)
+const char *bdrv_get_device_name(const BlockDriverState *bs)
{
- return bs->device_name;
+ return bs->blk ? blk_name(bs->blk) : "";
}
int bdrv_get_flags(BlockDriverState *bs)
@@ -5262,13 +5264,15 @@
void bdrv_eject(BlockDriverState *bs, bool eject_flag)
{
BlockDriver *drv = bs->drv;
+ const char *device_name;
if (drv && drv->bdrv_eject) {
drv->bdrv_eject(bs, eject_flag);
}
- if (bs->device_name[0] != '\0') {
- qapi_event_send_device_tray_moved(bdrv_get_device_name(bs),
+ device_name = bdrv_get_device_name(bs);
+ if (device_name[0] != '\0') {
+ qapi_event_send_device_tray_moved(device_name,
eject_flag, &error_abort);
}
}
@@ -5478,7 +5482,8 @@
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));
+ bdrv_get_device_name(bs),
+ error_get_pretty(blocker->reason));
}
return true;
}
