util: Introduce md_get_disk_info()

[thirdparty/mdadm.git] / mdopen.c

diff --git a/mdopen.c b/mdopen.c
index fc118840f15dd2790b9b5b2888f8ec0b2583e008..685ca3287304fc3b4f9ff22488cd717895dc4c21 100644 (file)
--- a/mdopen.c
+++ b/mdopen.c
@@ -1,7 +1,7 @@
 /*
  * mdadm - manage Linux "md" devices aka RAID arrays.
  *
- * Copyright (C) 2001-2012 Neil Brown <neilb@suse.de>
+ * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
  *
  *
  *    This program is free software; you can redistribute it and/or modify
@@ -144,7 +144,7 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
        struct createinfo *ci = conf_get_create_info();
        int parts;
        char *cname;
-       char devname[20];
+       char devname[37];
        char devnm[32];
        char cbuf[400];
        if (chosen == NULL)
@@ -173,8 +173,7 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
                        /* name *must* be mdXX or md_dXX in this context */
                        if (num < 0 ||
                            (strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
-                               pr_err("%s is an invalid name "
-                                       "for an md device.  Try /dev/md/%s\n",
+                               pr_err("%s is an invalid name for an md device.  Try /dev/md/%s\n",
                                        dev, dev+5);
                                return -1;
                        }
@@ -191,13 +190,11 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
                 * empty.
                 */
                if (strchr(cname, '/') != NULL) {
-                       pr_err("%s is an invalid name "
-                               "for an md device.\n", dev);
+                       pr_err("%s is an invalid name for an md device.\n", dev);
                        return -1;
                }
                if (cname[0] == 0) {
-                       pr_err("%s is an invalid name "
-                               "for an md device (empty!).", dev);
+                       pr_err("%s is an invalid name for an md device (empty!).", dev);
                        return -1;
                }
                if (num < 0) {
@@ -226,8 +223,7 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
        if (name && name[0] == 0)
                name = NULL;
        if (name && trustworthy == METADATA && use_mdp == 1) {
-               pr_err("%s is not allowed for a %s container. "
-                       "Consider /dev/md%d.\n", dev, name, num);
+               pr_err("%s is not allowed for a %s container. Consider /dev/md%d.\n", dev, name, num);
                return -1;
        }
        if (name && trustworthy == METADATA)
@@ -322,7 +318,7 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
        else if (num < 0) {
                /* need to choose a free number. */
                char *_devnm = find_free_devnm(use_mdp);
-               if (devnm == NULL) {
+               if (_devnm == NULL) {
                        pr_err("No avail md devices - aborting\n");
                        return -1;
                }
@@ -352,7 +348,7 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
                if (lstat(devname, &stb) == 0) {
                        /* Must be the correct device, else error */
                        if ((stb.st_mode&S_IFMT) != S_IFBLK ||
-                           stb.st_rdev != (dev_t)devnm2devid(devnm)) {
+                           stb.st_rdev != devnm2devid(devnm)) {
                                pr_err("%s exists but looks wrong, please fix\n",
                                        devname);
                                return -1;
@@ -420,9 +416,7 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
  */
 int open_mddev(char *dev, int report_errors)
 {
-       int mdfd = open(dev, O_RDWR);
-       if (mdfd < 0 && errno == EACCES)
-               mdfd = open(dev, O_RDONLY);
+       int mdfd = open(dev, O_RDONLY);
        if (mdfd < 0) {
                if (report_errors)
                        pr_err("error opening %s: %s\n",
@@ -432,9 +426,41 @@ int open_mddev(char *dev, int report_errors)
        if (md_get_version(mdfd) <= 0) {
                close(mdfd);
                if (report_errors)
-                       pr_err("%s does not appear to be "
-                               "an md device\n", dev);
+                       pr_err("%s does not appear to be an md device\n", dev);
                return -2;
        }
        return mdfd;
 }
+
+char *find_free_devnm(int use_partitions)
+{
+       static char devnm[32];
+       int devnum;
+       for (devnum = 127; devnum != 128;
+            devnum = devnum ? devnum-1 : (1<<9)-1) {
+
+               if (use_partitions)
+                       sprintf(devnm, "md_d%d", devnum);
+               else
+                       sprintf(devnm, "md%d", devnum);
+               if (mddev_busy(devnm))
+                       continue;
+               if (!conf_name_is_free(devnm))
+                       continue;
+               if (!use_udev()) {
+                       /* make sure it is new to /dev too, at least as a
+                        * non-standard */
+                       dev_t devid = devnm2devid(devnm);
+                       if (devid) {
+                               char *dn = map_dev(major(devid),
+                                                  minor(devid), 0);
+                               if (dn && ! is_standard(dn, NULL))
+                                       continue;
+                       }
+               }
+               break;
+       }
+       if (devnum == 128)
+               return NULL;
+       return devnm;
+}