[PATCH 1/2 v3] btrfs-progs: introduce test_issubvolname() for simplicity

[Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>]

From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>

There are many duplicated codes to check if the given string is
correct subvolume name. Introduce test_issubvolname() for this
purpose for simplicity.

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Mike Fleetwood <mike.fleetwood@googlemail.com>

---
changelog:
v2: Move test_issubvolname() to utils.c.
    Change the target branch to integ-20140729.
v3: Change the type of the 1st argument
    from "char *" to "const char *".
---
 cmds-subvolume.c |  9 +++------
 utils.c          | 12 ++++++++++++
 utils.h          |  1 +
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 8bdc447..c075fb2 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -127,8 +127,7 @@ static int cmd_subvol_create(int argc, char **argv)
 	dupdir = strdup(dst);
 	dstdir = dirname(dupdir);
 
-	if (!strcmp(newname, ".") || !strcmp(newname, "..") ||
-	     strchr(newname, '/') ){
+	if (!test_issubvolname(newname)) {
 		fprintf(stderr, "ERROR: incorrect subvolume name '%s'\n",
 			newname);
 		goto out;
@@ -302,8 +301,7 @@ again:
 	vname = basename(dupvname);
 	free(cpath);
 
-	if (!strcmp(vname, ".") || !strcmp(vname, "..") ||
-	     strchr(vname, '/')) {
+	if (!test_issubvolname(vname)) {
 		fprintf(stderr, "ERROR: incorrect subvolume name '%s'\n",
 			vname);
 		ret = 1;
@@ -711,8 +709,7 @@ static int cmd_snapshot(int argc, char **argv)
 		dstdir = dirname(dupdir);
 	}
 
-	if (!strcmp(newname, ".") || !strcmp(newname, "..") ||
-	     strchr(newname, '/') ){
+	if (!test_issubvolname(newname)) {
 		fprintf(stderr, "ERROR: incorrect snapshot name '%s'\n",
 			newname);
 		goto out;
diff --git a/utils.c b/utils.c
index d61cbec..d98aac8 100644
--- a/utils.c
+++ b/utils.c
@@ -2685,3 +2685,15 @@ int btrfs_read_sysfs(char path[PATH_MAX])
 	close(fd);
 	return atoi((const char *)&val);
 }
+
+/*
+ * test if name is a correct subvolume name
+ * this function return
+ * 0-> name is not a correct subvolume name
+ * 1-> name is a correct subvolume name
+ */
+int test_issubvolname(const char *name)
+{
+	return name[0] != '\0' && !strchr(name, '/') &&
+		strcmp(name, ".") && strcmp(name, "..");
+}
diff --git a/utils.h b/utils.h
index 0c9b65f..dad7d41 100644
--- a/utils.h
+++ b/utils.h
@@ -133,6 +133,7 @@ int get_fslist(struct btrfs_ioctl_fslist **out_fslist, u64 *out_count);
 int fsid_to_mntpt(__u8 *fsid, char *mntpt, int *mnt_cnt);
 
 int test_minimum_size(const char *file, u32 leafsize);
+int test_issubvolname(const char *name);
 
 /*
  * Btrfs minimum size calculation is complicated, it should include at least:
-- 
1.9.3