nilfs2: refactor parser of snapshot mount option

Move parser of snapshot mount option to a separate function
nilfs_parse_snapshot_option(), replace simple_strtoull() with
kstrtoull() to avoid checkpatch.pl warning "WARNING: simple_strtoull is
obsolete, use kstrtoull instead", and refine the error message of the
parser.

Link: http://lkml.kernel.org/r/1464875891-5443-9-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 33ba6f7..c95d369 100644 (file)
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1205,6 +1205,38 @@ struct nilfs_super_data {
        int flags;
 };
 
+static int nilfs_parse_snapshot_option(const char *option,
+                                      const substring_t *arg,
+                                      struct nilfs_super_data *sd)
+{
+       unsigned long long val;
+       const char *msg = NULL;
+       int err;
+
+       if (!(sd->flags & MS_RDONLY)) {
+               msg = "read-only option is not specified";
+               goto parse_error;
+       }
+
+       err = kstrtoull(arg->from, 0, &val);
+       if (err) {
+               if (err == -ERANGE)
+                       msg = "too large checkpoint number";
+               else
+                       msg = "malformed argument";
+               goto parse_error;
+       } else if (val == 0) {
+               msg = "invalid checkpoint number 0";
+               goto parse_error;
+       }
+       sd->cno = val;
+       return 0;
+
+parse_error:
+       nilfs_msg(NULL, KERN_ERR, "invalid option \"%s\": %s", option, msg);
+       return 1;
+}
+
 /**
  * nilfs_identify - pre-read mount options needed to identify mount instance
  * @data: mount options
@@ -1221,24 +1253,9 @@ static int nilfs_identify(char *data, struct nilfs_super_data *sd)
                p = strsep(&options, ",");
                if (p != NULL && *p) {
                        token = match_token(p, tokens, args);
-                       if (token == Opt_snapshot) {
-                               if (!(sd->flags & MS_RDONLY)) {
-                                       ret++;
-                               } else {
-                                       sd->cno = simple_strtoull(args[0].from,
-                                                                 NULL, 0);
-                                       /*
-                                        * No need to see the end pointer;
-                                        * match_token() has done syntax
-                                        * checking.
-                                        */
-                                       if (sd->cno == 0)
-                                               ret++;
-                               }
-                       }
-                       if (ret)
-                               nilfs_msg(NULL, KERN_ERR,
-                                         "invalid mount option: %s", p);
+                       if (token == Opt_snapshot)
+                               ret = nilfs_parse_snapshot_option(p, &args[0],
+                                                                 sd);
                }
                if (!options)
                        break;