[PATCH] md: helper function to match commands written to sysfs files

Commands written to sysfs files may, or my not, be \n terminated.  We want to
accept with case.  For this we use cmd_match.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 07f180f95b47967c68a6c4c7264c9916fe53c101..c1613854f38d716d7e3a2e02d5fcde69a5659f2b 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1525,6 +1525,26 @@ repeat:
 
 }
 
+/* words written to sysfs files may, or my not, be \n terminated.
+ * We want to accept with case. For this we use cmd_match.
+ */
+static int cmd_match(const char *cmd, const char *str)
+{
+       /* See if cmd, written into a sysfs file, matches
+        * str.  They must either be the same, or cmd can
+        * have a trailing newline
+        */
+       while (*cmd && *str && *cmd == *str) {
+               cmd++;
+               str++;
+       }
+       if (*cmd == '\n')
+               cmd++;
+       if (*str || *cmd)
+               return 0;
+       return 1;
+}
+
 struct rdev_sysfs_entry {
        struct attribute attr;
        ssize_t (*show)(mdk_rdev_t *, char *);
@@ -1799,7 +1819,7 @@ action_store(mddev_t *mddev, const char *page, size_t len)
        if (!mddev->pers || !mddev->pers->sync_request)
                return -EINVAL;
 
-       if (strcmp(page, "idle")==0 || strcmp(page, "idle\n")==0) {
+       if (cmd_match(page, "idle")) {
                if (mddev->sync_thread) {
                        set_bit(MD_RECOVERY_INTR, &mddev->recovery);
                        md_unregister_thread(mddev->sync_thread);
@@ -1812,13 +1832,12 @@ action_store(mddev_t *mddev, const char *page, size_t len)
        if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
            test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
                return -EBUSY;
-       if (strcmp(page, "resync")==0 || strcmp(page, "resync\n")==0 ||
-           strcmp(page, "recover")==0 || strcmp(page, "recover\n")==0)
+       if (cmd_match(page, "resync") || cmd_match(page, "recover"))
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
        else {
-               if (strcmp(page, "check")==0 || strcmp(page, "check\n")==0)
+               if (cmd_match(page, "check"))
                        set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
-               else if (strcmp(page, "repair")!=0 && strcmp(page, "repair\n")!=0)
+               else if (cmd_match(page, "repair"))
                        return -EINVAL;
                set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
                set_bit(MD_RECOVERY_SYNC, &mddev->recovery);