rbd: return snap name from rbd_add_parse_args()
This is the first of two patches aimed at isolating the code that
sets the mapping information into a single spot.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4377a83..1a64ba2 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2477,28 +2477,31 @@
}
/*
- * This fills in the pool_name, image_name, image_name_len, snap_name,
- * rbd_dev, rbd_md_name, and name fields of the given rbd_dev, based
- * on the list of monitor addresses and other options provided via
- * /sys/bus/rbd/add.
+ * This fills in the pool_name, image_name, image_name_len, rbd_dev,
+ * rbd_md_name, and name fields of the given rbd_dev, based on the
+ * list of monitor addresses and other options provided via
+ * /sys/bus/rbd/add. Returns a pointer to a dynamically-allocated
+ * copy of the snapshot name to map if successful, or a
+ * pointer-coded error otherwise.
*
* Note: rbd_dev is assumed to have been initially zero-filled.
*/
-static int rbd_add_parse_args(struct rbd_device *rbd_dev,
- const char *buf,
- const char **mon_addrs,
- size_t *mon_addrs_size,
- char *options,
- size_t options_size)
+static char *rbd_add_parse_args(struct rbd_device *rbd_dev,
+ const char *buf,
+ const char **mon_addrs,
+ size_t *mon_addrs_size,
+ char *options,
+ size_t options_size)
{
size_t len;
- int ret;
+ char *err_ptr = ERR_PTR(-EINVAL);
+ char *snap_name;
/* The first four tokens are required */
len = next_token(&buf);
if (!len)
- return -EINVAL;
+ return err_ptr;
*mon_addrs_size = len + 1;
*mon_addrs = buf;
@@ -2506,9 +2509,9 @@
len = copy_token(&buf, options, options_size);
if (!len || len >= options_size)
- return -EINVAL;
+ return err_ptr;
- ret = -ENOMEM;
+ err_ptr = ERR_PTR(-ENOMEM);
rbd_dev->pool_name = dup_token(&buf, NULL);
if (!rbd_dev->pool_name)
goto out_err;
@@ -2526,26 +2529,21 @@
goto out_err;
sprintf(rbd_dev->header_name, "%s%s", rbd_dev->image_name, RBD_SUFFIX);
- /*
- * The snapshot name is optional. If none is is supplied,
- * we use the default value.
- */
- rbd_dev->mapping.snap_name = dup_token(&buf, &len);
- if (!rbd_dev->mapping.snap_name)
- goto out_err;
+ /* Snapshot name is optional */
+ len = next_token(&buf);
if (!len) {
- /* Replace the empty name with the default */
- kfree(rbd_dev->mapping.snap_name);
- rbd_dev->mapping.snap_name
- = kmalloc(sizeof (RBD_SNAP_HEAD_NAME), GFP_KERNEL);
- if (!rbd_dev->mapping.snap_name)
- goto out_err;
-
- memcpy(rbd_dev->mapping.snap_name, RBD_SNAP_HEAD_NAME,
- sizeof (RBD_SNAP_HEAD_NAME));
+ buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
+ len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
}
+ snap_name = kmalloc(len + 1, GFP_KERNEL);
+ if (!snap_name)
+ goto out_err;
+ memcpy(snap_name, buf, len);
+ *(snap_name + len) = '\0';
- return 0;
+dout(" SNAP_NAME is <%s>, len is %zd\n", snap_name, len);
+
+ return snap_name;
out_err:
kfree(rbd_dev->header_name);
@@ -2556,7 +2554,7 @@
kfree(rbd_dev->pool_name);
rbd_dev->pool_name = NULL;
- return ret;
+ return err_ptr;
}
static ssize_t rbd_add(struct bus_type *bus,
@@ -2569,6 +2567,7 @@
size_t mon_addrs_size = 0;
struct ceph_osd_client *osdc;
int rc = -ENOMEM;
+ char *snap_name;
if (!try_module_get(THIS_MODULE))
return -ENODEV;
@@ -2595,10 +2594,13 @@
sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
/* parse add command */
- rc = rbd_add_parse_args(rbd_dev, buf, &mon_addrs, &mon_addrs_size,
- options, count);
- if (rc)
+ snap_name = rbd_add_parse_args(rbd_dev, buf,
+ &mon_addrs, &mon_addrs_size, options, count);
+ if (IS_ERR(snap_name)) {
+ rc = PTR_ERR(snap_name);
goto err_put_id;
+ }
+ rbd_dev->mapping.snap_name = snap_name;
rc = rbd_get_client(rbd_dev, mon_addrs, mon_addrs_size - 1, options);
if (rc < 0)