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-rw-r--r--drivers/md/dm-ioctl.c103
-rw-r--r--include/linux/dm-ioctl.h12
2 files changed, 87 insertions, 28 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 4b54618b4159..f3481d922206 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -295,19 +295,55 @@ retry:
DMWARN("remove_all left %d open device(s)", dev_skipped);
}
+/*
+ * Set the uuid of a hash_cell that isn't already set.
+ */
+static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
+{
+ mutex_lock(&dm_hash_cells_mutex);
+ hc->uuid = new_uuid;
+ mutex_unlock(&dm_hash_cells_mutex);
+
+ list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
+}
+
+/*
+ * Changes the name of a hash_cell and returns the old name for
+ * the caller to free.
+ */
+static char *__change_cell_name(struct hash_cell *hc, char *new_name)
+{
+ char *old_name;
+
+ /*
+ * Rename and move the name cell.
+ */
+ list_del(&hc->name_list);
+ old_name = hc->name;
+
+ mutex_lock(&dm_hash_cells_mutex);
+ hc->name = new_name;
+ mutex_unlock(&dm_hash_cells_mutex);
+
+ list_add(&hc->name_list, _name_buckets + hash_str(new_name));
+
+ return old_name;
+}
+
static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
const char *new)
{
- char *new_name, *old_name;
+ char *new_data, *old_name = NULL;
struct hash_cell *hc;
struct dm_table *table;
struct mapped_device *md;
+ unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
/*
* duplicate new.
*/
- new_name = kstrdup(new, GFP_KERNEL);
- if (!new_name)
+ new_data = kstrdup(new, GFP_KERNEL);
+ if (!new_data)
return ERR_PTR(-ENOMEM);
down_write(&_hash_lock);
@@ -315,13 +351,19 @@ static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
/*
* Is new free ?
*/
- hc = __get_name_cell(new);
+ if (change_uuid)
+ hc = __get_uuid_cell(new);
+ else
+ hc = __get_name_cell(new);
+
if (hc) {
- DMWARN("asked to rename to an already-existing name %s -> %s",
+ DMWARN("Unable to change %s on mapped device %s to one that "
+ "already exists: %s",
+ change_uuid ? "uuid" : "name",
param->name, new);
dm_put(hc->md);
up_write(&_hash_lock);
- kfree(new_name);
+ kfree(new_data);
return ERR_PTR(-EBUSY);
}
@@ -330,22 +372,30 @@ static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
*/
hc = __get_name_cell(param->name);
if (!hc) {
- DMWARN("asked to rename a non-existent device %s -> %s",
- param->name, new);
+ DMWARN("Unable to rename non-existent device, %s to %s%s",
+ param->name, change_uuid ? "uuid " : "", new);
up_write(&_hash_lock);
- kfree(new_name);
+ kfree(new_data);
return ERR_PTR(-ENXIO);
}
/*
- * rename and move the name cell.
+ * Does this device already have a uuid?
*/
- list_del(&hc->name_list);
- old_name = hc->name;
- mutex_lock(&dm_hash_cells_mutex);
- hc->name = new_name;
- mutex_unlock(&dm_hash_cells_mutex);
- list_add(&hc->name_list, _name_buckets + hash_str(new_name));
+ if (change_uuid && hc->uuid) {
+ DMWARN("Unable to change uuid of mapped device %s to %s "
+ "because uuid is already set to %s",
+ param->name, new, hc->uuid);
+ dm_put(hc->md);
+ up_write(&_hash_lock);
+ kfree(new_data);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (change_uuid)
+ __set_cell_uuid(hc, new_data);
+ else
+ old_name = __change_cell_name(hc, new_data);
/*
* Wake up any dm event waiters.
@@ -774,21 +824,24 @@ static int invalid_str(char *str, void *end)
static int dev_rename(struct dm_ioctl *param, size_t param_size)
{
int r;
- char *new_name = (char *) param + param->data_start;
+ char *new_data = (char *) param + param->data_start;
struct mapped_device *md;
+ unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
- if (new_name < param->data ||
- invalid_str(new_name, (void *) param + param_size) ||
- strlen(new_name) > DM_NAME_LEN - 1) {
- DMWARN("Invalid new logical volume name supplied.");
+ if (new_data < param->data ||
+ invalid_str(new_data, (void *) param + param_size) ||
+ strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
+ DMWARN("Invalid new mapped device name or uuid string supplied.");
return -EINVAL;
}
- r = check_name(new_name);
- if (r)
- return r;
+ if (!change_uuid) {
+ r = check_name(new_data);
+ if (r)
+ return r;
+ }
- md = dm_hash_rename(param, new_name);
+ md = dm_hash_rename(param, new_data);
if (IS_ERR(md))
return PTR_ERR(md);
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 49eab360d5d4..e453e1174ae1 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -44,7 +44,7 @@
* Remove a device, destroy any tables.
*
* DM_DEV_RENAME:
- * Rename a device.
+ * Rename a device or set its uuid if none was previously supplied.
*
* DM_SUSPEND:
* This performs both suspend and resume, depending which flag is
@@ -267,9 +267,9 @@ enum {
#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
#define DM_VERSION_MAJOR 4
-#define DM_VERSION_MINOR 18
+#define DM_VERSION_MINOR 19
#define DM_VERSION_PATCHLEVEL 0
-#define DM_VERSION_EXTRA "-ioctl (2010-06-29)"
+#define DM_VERSION_EXTRA "-ioctl (2010-10-14)"
/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
@@ -322,4 +322,10 @@ enum {
*/
#define DM_UEVENT_GENERATED_FLAG (1 << 13) /* Out */
+/*
+ * If set, rename changes the uuid not the name. Only permitted
+ * if no uuid was previously supplied: an existing uuid cannot be changed.
+ */
+#define DM_UUID_FLAG (1 << 14) /* In */
+
#endif /* _LINUX_DM_IOCTL_H */