rbd: do all argument parsing in one place

This patch makes rbd_add_parse_args() be the single place all
argument parsing occurs for an image map request:
    - Move the ceph_parse_options() call into that function
    - Use local variables rather than parameters to hold the list
      of monitor addresses supplied
    - Rather than returning it, pass the snapshot name (and its
      length) back via parameters
    - Have the function return a ceph_options structure pointer

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 37 insertions, 40 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index e83bddcca34e..68447d83288c 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2845,24 +2845,27 @@ static inline char *dup_token(const char **buf, size_t *lenp)
  *
  * Note: rbd_dev is assumed to have been initially zero-filled.
  */
-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)
+static struct ceph_options *rbd_add_parse_args(struct rbd_device *rbd_dev,
+                                                const char *buf,
+                                                char *options,
+                                                size_t options_size,
+                                                char **snap_name,
+                                                size_t *snap_name_len)
 {
         size_t len;
-        char *err_ptr = ERR_PTR(-EINVAL);
-        char *snap_name;
+        const char *mon_addrs;
+        size_t mon_addrs_size;
+        struct rbd_options rbd_opts;
+        struct ceph_options *ceph_opts;
+        struct ceph_options *err_ptr = ERR_PTR(-EINVAL);
 
         /* The first four tokens are required */
 
         len = next_token(&buf);
         if (!len)
                 return err_ptr;
-        *mon_addrs_size = len + 1;
-        *mon_addrs = buf;
+        mon_addrs_size = len + 1;
+        mon_addrs = buf;
 
         buf += len;
 
@@ -2890,14 +2893,27 @@ static char *rbd_add_parse_args(struct rbd_device *rbd_dev,
                 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)
+        *snap_name = kmalloc(len + 1, GFP_KERNEL);
+        if (!*snap_name)
                 goto out_err;
-        memcpy(snap_name, buf, len);
-        *(snap_name + len) = '\0';
+        memcpy(*snap_name, buf, len);
+        *(*snap_name + len) = '\0';
+        *snap_name_len = len;
+        /* Initialize all rbd options to the defaults */
 
-        return snap_name;
+        rbd_opts.read_only = RBD_READ_ONLY_DEFAULT;
 
+        ceph_opts = ceph_parse_options(options, mon_addrs,
+                                        mon_addrs + mon_addrs_size - 1,
+                                        parse_rbd_opts_token, &rbd_opts);
+
+        /* Record the parsed rbd options */
+
+        if (!IS_ERR(ceph_opts)) {
+                rbd_dev->mapping.read_only = rbd_opts.read_only;
+        }
+
+        return ceph_opts;
 out_err:
         kfree(rbd_dev->image_name);
         rbd_dev->image_name = NULL;
@@ -3114,10 +3130,8 @@ static ssize_t rbd_add(struct bus_type *bus,
 {
         char *options;
         struct rbd_device *rbd_dev = NULL;
-        const char *mon_addrs = NULL;
-        size_t mon_addrs_size = 0;
         char *snap_name;
-        struct rbd_options rbd_opts;
+        size_t snap_name_len = 0;
         struct ceph_options *ceph_opts;
         struct ceph_osd_client *osdc;
         int rc = -ENOMEM;
@@ -3139,32 +3153,16 @@ static ssize_t rbd_add(struct bus_type *bus,
         init_rwsem(&rbd_dev->header_rwsem);
 
         /* parse add command */
-        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_out_mem;
-        }
-
-        /* Initialize all rbd options to the defaults */
-
-        rbd_opts.read_only = RBD_READ_ONLY_DEFAULT;
-
-        ceph_opts = ceph_parse_options(options, mon_addrs,
-                                        mon_addrs + mon_addrs_size - 1,
-                                        parse_rbd_opts_token, &rbd_opts);
+        ceph_opts = rbd_add_parse_args(rbd_dev, buf, options, count,
+                                &snap_name, &snap_name_len);
         if (IS_ERR(ceph_opts)) {
                 rc = PTR_ERR(ceph_opts);
-                goto err_out_args;
+                goto err_out_mem;
         }
 
-        /* Record the parsed rbd options */
-
-        rbd_dev->mapping.read_only = rbd_opts.read_only;
-
         rc = rbd_get_client(rbd_dev, ceph_opts);
         if (rc < 0)
-                goto err_out_opts;
+                goto err_out_args;
         ceph_opts = NULL;       /* ceph_opts now owned by rbd_dev client */
 
         /* pick the pool */
@@ -3257,10 +3255,9 @@ err_out_client:
         kfree(rbd_dev->header_name);
         rbd_put_client(rbd_dev);
         kfree(rbd_dev->image_id);
-err_out_opts:
+err_out_args:
         if (ceph_opts)
                 ceph_destroy_options(ceph_opts);
-err_out_args:
         kfree(rbd_dev->snap_name);
         kfree(rbd_dev->image_name);
         kfree(rbd_dev->pool_name);