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authorMax Reitz <mreitz@redhat.com>2016-03-16 19:54:37 +0100
committerKevin Wolf <kwolf@redhat.com>2016-03-17 15:47:56 +0100
commite5e785500bf1ca286f9069bc13f3ed8cb2e9eb8a (patch)
tree2f057a2d398d1bc1f7bad01e211695a8f59e4f87
parent2cf22d6a1a542b7775ba6945a0423b41325db45f (diff)
blockdev: Separate BB name management
Introduce separate functions (monitor_add_blk() and monitor_remove_blk()) which set or unset a BB name. Since the name is equivalent to the monitor's reference to a BB, adding a name the same as declaring the BB to be monitor-owned and removing it revokes this status, hence the function names. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--block/block-backend.c92
-rw-r--r--include/sysemu/block-backend.h2
2 files changed, 63 insertions, 31 deletions
diff --git a/block/block-backend.c b/block/block-backend.c
index 35206be845..a5b950c771 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -90,30 +90,17 @@ BlockBackend *blk_new(const char *name, Error **errp)
{
BlockBackend *blk;
- assert(name && name[0]);
- if (!id_wellformed(name)) {
- error_setg(errp, "Invalid device name");
- return NULL;
- }
- if (blk_by_name(name)) {
- error_setg(errp, "Device with id '%s' already exists", name);
- return NULL;
- }
- if (bdrv_find_node(name)) {
- error_setg(errp,
- "Device name '%s' conflicts with an existing node name",
- name);
- return NULL;
- }
-
blk = g_new0(BlockBackend, 1);
- blk->name = g_strdup(name);
blk->refcnt = 1;
notifier_list_init(&blk->remove_bs_notifiers);
notifier_list_init(&blk->insert_bs_notifiers);
QTAILQ_INSERT_TAIL(&block_backends, blk, link);
- QTAILQ_INSERT_TAIL(&monitor_block_backends, blk, monitor_link);
+
+ if (!monitor_add_blk(blk, name, errp)) {
+ blk_unref(blk);
+ return NULL;
+ }
return blk;
}
@@ -174,7 +161,10 @@ BlockBackend *blk_new_open(const char *name, const char *filename,
static void blk_delete(BlockBackend *blk)
{
+ monitor_remove_blk(blk);
+
assert(!blk->refcnt);
+ assert(!blk->name);
assert(!blk->dev);
if (blk->bs) {
blk_remove_bs(blk);
@@ -185,15 +175,7 @@ static void blk_delete(BlockBackend *blk)
g_free(blk->root_state.throttle_group);
throttle_group_unref(blk->root_state.throttle_state);
}
-
- /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */
- if (blk->name[0]) {
- QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link);
- }
- g_free(blk->name);
-
QTAILQ_REMOVE(&block_backends, blk, link);
-
drive_info_del(blk->legacy_dinfo);
block_acct_cleanup(&blk->stats);
g_free(blk);
@@ -280,13 +262,62 @@ BlockBackend *blk_next(BlockBackend *blk)
}
/*
+ * Add a BlockBackend into the list of backends referenced by the monitor, with
+ * the given @name acting as the handle for the monitor.
+ * Strictly for use by blockdev.c.
+ *
+ * @name must not be null or empty.
+ *
+ * Returns true on success and false on failure. In the latter case, an Error
+ * object is returned through @errp.
+ */
+bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp)
+{
+ assert(!blk->name);
+ assert(name && name[0]);
+
+ if (!id_wellformed(name)) {
+ error_setg(errp, "Invalid device name");
+ return false;
+ }
+ if (blk_by_name(name)) {
+ error_setg(errp, "Device with id '%s' already exists", name);
+ return false;
+ }
+ if (bdrv_find_node(name)) {
+ error_setg(errp,
+ "Device name '%s' conflicts with an existing node name",
+ name);
+ return false;
+ }
+
+ blk->name = g_strdup(name);
+ QTAILQ_INSERT_TAIL(&monitor_block_backends, blk, monitor_link);
+ return true;
+}
+
+/*
+ * Remove a BlockBackend from the list of backends referenced by the monitor.
+ * Strictly for use by blockdev.c.
+ */
+void monitor_remove_blk(BlockBackend *blk)
+{
+ if (!blk->name) {
+ return;
+ }
+
+ QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link);
+ g_free(blk->name);
+ blk->name = NULL;
+}
+
+/*
* Return @blk's name, a non-null string.
- * Wart: the name is empty iff @blk has been hidden with
- * blk_hide_on_behalf_of_hmp_drive_del().
+ * Returns an empty string iff @blk is not referenced by the monitor.
*/
const char *blk_name(BlockBackend *blk)
{
- return blk->name;
+ return blk->name ?: "";
}
/*
@@ -377,8 +408,7 @@ BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo)
*/
void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
{
- QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link);
- blk->name[0] = 0;
+ monitor_remove_blk(blk);
if (blk->bs) {
bdrv_make_anon(blk->bs);
}
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 84612cefc8..c906c209b1 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -71,6 +71,8 @@ void blk_remove_all_bs(void);
const char *blk_name(BlockBackend *blk);
BlockBackend *blk_by_name(const char *name);
BlockBackend *blk_next(BlockBackend *blk);
+bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
+void monitor_remove_blk(BlockBackend *blk);
BlockDriverState *blk_bs(BlockBackend *blk);
void blk_remove_bs(BlockBackend *blk);