mdadm: check value returned by snprintf against errors

[thirdparty/mdadm.git] / lib.c

diff --git a/lib.c b/lib.c
index 057ee52311f14ed8b3c03de90783c2ddfe94dcc0..60890b95baf888762e0a1cf9c919e1314abf1285 100644 (file)
--- a/lib.c
+++ b/lib.c
@@ -61,10 +61,10 @@ int get_mdp_major(void)
        return mdp_major;
 }
 
-char *devid2kname(int devid)
+char *devid2kname(dev_t devid)
 {
        char path[30];
-       char link[200];
+       char link[PATH_MAX];
        static char devnm[32];
        char *cp;
        int n;
@@ -73,8 +73,7 @@ char *devid2kname(int devid)
         * /sys/dev/block/%d:%d link which must look like
         * and take the last component.
         */
-       sprintf(path, "/sys/dev/block/%d:%d", major(devid),
-               minor(devid));
+       sprintf(path, "/sys/dev/block/%d:%d", major(devid), minor(devid));
        n = readlink(path, link, sizeof(link) - 1);
        if (n > 0) {
                link[n] = 0;
@@ -163,6 +162,35 @@ char *fd2devnm(int fd)
        return NULL;
 }
 
+/* When we create a new array, we don't want the content to
+ * be immediately examined by udev - it is probably meaningless.
+ * So create /run/mdadm/creating-mdXXX and expect that a udev
+ * rule will noticed this and act accordingly.
+ */
+static char block_path[] = "/run/mdadm/creating-%s";
+static char *unblock_path = NULL;
+void udev_block(char *devnm)
+{
+       int fd;
+       char *path = NULL;
+
+       xasprintf(&path, block_path, devnm);
+       fd = open(path, O_CREAT|O_RDWR, 0600);
+       if (fd >= 0) {
+               close(fd);
+               unblock_path = path;
+       } else
+               free(path);
+}
+
+void udev_unblock(void)
+{
+       if (unblock_path)
+               unlink(unblock_path);
+       free(unblock_path);
+       unblock_path = NULL;
+}
+
 /*
  * convert a major/minor pair for a block device into a name in /dev, if possible.
  * On the first call, walk /dev collecting name.