]> git.ipfire.org Git - thirdparty/mdadm.git/blobdiff - util.c
Teach sysfs_add_disk() callers to use ->recovery_start versus 'insync' parameter
[thirdparty/mdadm.git] / util.c
diff --git a/util.c b/util.c
index 4a751aaf1350f8db0c96d62ab5bcf69a3f6c7916..05be64c6add692959d89e94ab00cd83963d2aa02 100644 (file)
--- a/util.c
+++ b/util.c
@@ -1,7 +1,7 @@
 /*
  * mdadm - manage Linux "md" devices aka RAID arrays.
  *
- * Copyright (C) 2001-2006 Neil Brown <neilb@suse.de>
+ * Copyright (C) 2001-2009 Neil Brown <neilb@suse.de>
  *
  *
  *    This program is free software; you can redistribute it and/or modify
  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  *    Author: Neil Brown
- *    Email: <neilb@cse.unsw.edu.au>
- *    Paper: Neil Brown
- *           School of Computer Science and Engineering
- *           The University of New South Wales
- *           Sydney, 2052
- *           Australia
+ *    Email: <neilb@suse.de>
  */
 
 #include       "mdadm.h"
 #include       "md_p.h"
+#include       <sys/socket.h>
 #include       <sys/utsname.h>
+#include       <sys/wait.h>
+#include       <sys/un.h>
 #include       <ctype.h>
+#include       <dirent.h>
+#include       <signal.h>
 
 /*
  * following taken from linux/blkpg.h because they aren't
@@ -149,6 +149,73 @@ int get_linux_version()
        return (a*1000000)+(b*1000)+c;
 }
 
+#ifndef MDASSEMBLE
+long long parse_size(char *size)
+{
+       /* parse 'size' which should be a number optionally
+        * followed by 'K', 'M', or 'G'.
+        * Without a suffix, K is assumed.
+        * Number returned is in sectors (half-K)
+        */
+       char *c;
+       long long s = strtoll(size, &c, 10);
+       if (s > 0) {
+               switch (*c) {
+               case 'K':
+                       c++;
+               default:
+                       s *= 2;
+                       break;
+               case 'M':
+                       c++;
+                       s *= 1024 * 2;
+                       break;
+               case 'G':
+                       c++;
+                       s *= 1024 * 1024 * 2;
+                       break;
+               }
+       }
+       if (*c)
+               s = 0;
+       return s;
+}
+
+int parse_layout_10(char *layout)
+{
+       int copies, rv;
+       char *cp;
+       /* Parse the layout string for raid10 */
+       /* 'f', 'o' or 'n' followed by a number <= raid_disks */
+       if ((layout[0] !=  'n' && layout[0] != 'f' && layout[0] != 'o') ||
+           (copies = strtoul(layout+1, &cp, 10)) < 1 ||
+           copies > 200 ||
+           *cp)
+               return -1;
+       if (layout[0] == 'n')
+               rv = 256 + copies;
+       else if (layout[0] == 'o')
+               rv = 0x10000 + (copies<<8) + 1;
+       else
+               rv = 1 + (copies<<8);
+       return rv;
+}
+
+int parse_layout_faulty(char *layout)
+{
+       /* Parse the layout string for 'faulty' */
+       int ln = strcspn(layout, "0123456789");
+       char *m = strdup(layout);
+       int mode;
+       m[ln] = 0;
+       mode = map_name(faultylayout, m);
+       if (mode == UnSet)
+               return -1;
+
+       return mode | (atoi(layout+ln)<< ModeShift);
+}
+#endif
+
 void remove_partitions(int fd)
 {
        /* remove partitions from this block devices.
@@ -194,9 +261,9 @@ int enough(int level, int raid_disks, int layout, int clean,
                } while (first != 0);
                return 1;
 
-       case -4:
+       case LEVEL_MULTIPATH:
                return avail_disks>= 1;
-       case -1:
+       case LEVEL_LINEAR:
        case 0:
                return avail_disks == raid_disks;
        case 1:
@@ -217,8 +284,13 @@ int enough(int level, int raid_disks, int layout, int clean,
        }
 }
 
+const int uuid_match_any[4] = { ~0, ~0, ~0, ~0 };
 int same_uuid(int a[4], int b[4], int swapuuid)
 {
+       if (memcmp(a, uuid_match_any, sizeof(int[4])) == 0 ||
+           memcmp(b, uuid_match_any, sizeof(int[4])) == 0)
+               return 1;
+
        if (swapuuid) {
                /* parse uuids are hostendian.
                 * uuid's from some superblocks are big-ending
@@ -264,6 +336,31 @@ void copy_uuid(void *a, int b[4], int swapuuid)
                memcpy(a, b, 16);
 }
 
+char *__fname_from_uuid(int id[4], int swap, char *buf, char sep)
+{
+       int i, j;
+       char uuid[16];
+       char *c = buf;
+       strcpy(c, "UUID-");
+       c += strlen(c);
+       copy_uuid(uuid, id, swap);
+       for (i = 0; i < 4; i++) {
+               if (i)
+                       *c++ = sep;
+               for (j = 3; j >= 0; j--) {
+                       sprintf(c,"%02x", (unsigned char) uuid[j+4*i]);
+                       c+= 2;
+               }
+       }
+       return buf;
+
+}
+
+char *fname_from_uuid(struct supertype *st, struct mdinfo *info, char *buf, char sep)
+{
+       return __fname_from_uuid(info->uuid, st->ss->swapuuid, buf, sep);
+}
+
 #ifndef MDASSEMBLE
 int check_ext2(int fd, char *name)
 {
@@ -322,19 +419,18 @@ int check_reiser(int fd, char *name)
 
 int check_raid(int fd, char *name)
 {
-       void *super;
        struct mdinfo info;
        time_t crtime;
        char *level;
        struct supertype *st = guess_super(fd);
 
        if (!st) return 0;
-       st->ss->load_super(st, fd, &super, name);
+       st->ss->load_super(st, fd, name);
        /* Looks like a raid array .. */
        fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
                name);
-       st->ss->getinfo_super(&info, super);
-       free(super);
+       st->ss->getinfo_super(st, &info);
+       st->ss->free_super(st);
        crtime = info.array.ctime;
        level = map_num(pers, info.array.level);
        if (!level) level = "-unknown-";
@@ -390,6 +486,9 @@ int is_standard(char *dev, int *nump)
        /* tests if dev is a "standard" md dev name.
         * i.e if the last component is "/dNN" or "/mdNN",
         * where NN is a string of digits
+        * Returns 1 if a partitionable standard,
+        *   -1 if non-partitonable,
+        *   0 if not a standard name.
         */
        char *d = strrchr(dev, '/');
        int type=0;
@@ -399,7 +498,7 @@ int is_standard(char *dev, int *nump)
        if (strncmp(d, "/d",2)==0)
                d += 2, type=1; /* /dev/md/dN{pM} */
        else if (strncmp(d, "/md_d", 5)==0)
-               d += 5, type=1; /* /dev/md_dNpM */
+               d += 5, type=1; /* /dev/md_dN{pM} */
        else if (strncmp(d, "/md", 3)==0)
                d += 3, type=-1; /* /dev/mdN */
        else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
@@ -434,8 +533,10 @@ int devlist_ready = 0;
 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 {
        struct stat st;
+
        if (S_ISLNK(stb->st_mode)) {
-               stat(name, &st);
+               if (stat(name, &st) != 0)
+                       return 0;
                stb = &st;
        }
 
@@ -476,14 +577,13 @@ int nftw(const char *path, int (*han)(const char *name, const struct stat *stb,
 /*
  * Find a block device with the right major/minor number.
  * If we find multiple names, choose the shortest.
- * If we find a non-standard name, it is probably there
- * deliberately so prefer it over a standard name.
+ * If we find a name in /dev/md/, we prefer that.
  * This applies only to names for MD devices.
  */
 char *map_dev(int major, int minor, int create)
 {
        struct devmap *p;
-       char *std = NULL, *nonstd=NULL;
+       char *regular = NULL, *preferred=NULL;
        int did_check = 0;
 
        if (major == 0 && minor == 0)
@@ -510,27 +610,27 @@ char *map_dev(int major, int minor, int create)
        for (p=devlist; p; p=p->next)
                if (p->major == major &&
                    p->minor == minor) {
-                       if (is_standard(p->name, NULL)) {
-                               if (std == NULL ||
-                                   strlen(p->name) < strlen(std))
-                                       std = p->name;
+                       if (strncmp(p->name, "/dev/md/",8) == 0) {
+                               if (preferred == NULL ||
+                                   strlen(p->name) < strlen(preferred))
+                                       preferred = p->name;
                        } else {
-                               if (nonstd == NULL ||
-                                   strlen(p->name) < strlen(nonstd))
-                                       nonstd = p->name;
+                               if (regular == NULL ||
+                                   strlen(p->name) < strlen(regular))
+                                       regular = p->name;
                        }
                }
-       if (!std && !nonstd && !did_check) {
+       if (!regular && !preferred && !did_check) {
                devlist_ready = 0;
                goto retry;
        }
-       if (create && !std && !nonstd) {
+       if (create && !regular && !preferred) {
                static char buf[30];
                snprintf(buf, sizeof(buf), "%d:%d", major, minor);
-               nonstd = buf;
+               regular = buf;
        }
 
-       return nonstd ? nonstd : std;
+       return preferred ? preferred : regular;
 }
 
 unsigned long calc_csum(void *super, int bytes)
@@ -607,9 +707,42 @@ char *human_size_brief(long long bytes)
                        );
        return buf;
 }
+
+void print_r10_layout(int layout)
+{
+       int near = layout & 255;
+       int far = (layout >> 8) & 255;
+       int offset = (layout&0x10000);
+       char *sep = "";
+
+       if (near != 1) {
+               printf("%s near=%d", sep, near);
+               sep = ",";
+       }
+       if (far != 1)
+               printf("%s %s=%d", sep, offset?"offset":"far", far);
+       if (near*far == 1)
+               printf("NO REDUNDANCY");
+}
 #endif
 
-#if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
+unsigned long long calc_array_size(int level, int raid_disks, int layout,
+                                  int chunksize, unsigned long long devsize)
+{
+       int data_disks = 0;
+       switch (level) {
+       case 0: data_disks = raid_disks; break;
+       case 1: data_disks = 1; break;
+       case 4:
+       case 5: data_disks = raid_disks - 1; break;
+       case 6: data_disks = raid_disks - 2; break;
+       case 10: data_disks = raid_disks / (layout & 255) / ((layout>>8)&255);
+               break;
+       }
+       devsize &= ~(unsigned long long)((chunksize>>9)-1);
+       return data_disks * devsize;
+}
+
 int get_mdp_major(void)
 {
 static int mdp_major = -1;
@@ -638,8 +771,7 @@ static int mdp_major = -1;
        return mdp_major;
 }
 
-
-
+#if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 char *get_md_name(int dev)
 {
        /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
@@ -693,6 +825,29 @@ void put_md_name(char *name)
        if (strncmp(name, "/dev/.tmp.md", 12)==0)
                unlink(name);
 }
+
+int find_free_devnum(int use_partitions)
+{
+       int devnum;
+       for (devnum = 127; devnum != 128;
+            devnum = devnum ? devnum-1 : (1<<20)-1) {
+               char *dn;
+               int _devnum;
+
+               _devnum = use_partitions ? (-1-devnum) : devnum;
+               if (mddev_busy(_devnum))
+                       continue;
+               /* make sure it is new to /dev too, at least as a
+                * non-standard */
+               dn = map_dev(dev2major(_devnum), dev2minor(_devnum), 0);
+               if (dn && ! is_standard(dn, NULL))
+                       continue;
+               break;
+       }
+       if (devnum == 128)
+               return NoMdDev;
+       return use_partitions ? (-1-devnum) : devnum;
+}
 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 
 int dev_open(char *dev, int flags)
@@ -712,32 +867,163 @@ int dev_open(char *dev, int flags)
        if (e > dev && *e == ':' && e[1] &&
            (minor = strtoul(e+1, &e, 0)) >= 0 &&
            *e == 0) {
-               snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d", major, minor);
+               snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d:%d",
+                        (int)getpid(), major, minor);
                if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
-                       fd = open(devname, flags);
+                       fd = open(devname, flags|O_DIRECT);
                        unlink(devname);
                }
        } else
-               fd = open(dev, flags);
+               fd = open(dev, flags|O_DIRECT);
        return fd;
 }
 
-struct superswitch *superlist[] = { &super0, &super1, NULL };
+int open_dev(int devnum)
+{
+       char buf[20];
+
+       sprintf(buf, "%d:%d", dev2major(devnum), dev2minor(devnum));
+       return dev_open(buf, O_RDWR);
+}
+
+int open_dev_excl(int devnum)
+{
+       char buf[20];
+       int i;
+
+       sprintf(buf, "%d:%d", dev2major(devnum), dev2minor(devnum));
+       for (i=0 ; i<25 ; i++) {
+               int fd = dev_open(buf, O_RDWR|O_EXCL);
+               if (fd >= 0)
+                       return fd;
+               if (errno != EBUSY)
+                       return fd;
+               usleep(200000);
+       }
+       return -1;
+}
+
+int same_dev(char *one, char *two)
+{
+       struct stat st1, st2;
+       if (stat(one, &st1) != 0)
+               return 0;
+       if (stat(two, &st2) != 0)
+               return 0;
+       if ((st1.st_mode & S_IFMT) != S_IFBLK)
+               return 0;
+       if ((st2.st_mode & S_IFMT) != S_IFBLK)
+               return 0;
+       return st1.st_rdev == st2.st_rdev;
+}
 
-struct supertype *super_by_version(int vers, int minor)
+void wait_for(char *dev, int fd)
 {
-       struct supertype *st = malloc(sizeof(*st));
-       if (!st) return st;
-       if (vers == 0) {
-               st->ss = &super0;
-               st->max_devs = MD_SB_DISKS;
+       int i;
+       struct stat stb_want;
+
+       if (fstat(fd, &stb_want) != 0 ||
+           (stb_want.st_mode & S_IFMT) != S_IFBLK)
+               return;
+
+       for (i=0 ; i<25 ; i++) {
+               struct stat stb;
+               if (stat(dev, &stb) == 0 &&
+                   (stb.st_mode & S_IFMT) == S_IFBLK &&
+                   (stb.st_rdev == stb_want.st_rdev))
+                       return;
+               usleep(200000);
        }
+       if (i == 25)
+               dprintf("%s: timeout waiting for %s\n", __func__, dev);
+}
+
+struct superswitch *superlist[] = { &super0, &super1, &super_ddf, &super_imsm, NULL };
+
+#if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
+
+struct supertype *super_by_fd(int fd)
+{
+       mdu_array_info_t array;
+       int vers;
+       int minor;
+       struct supertype *st = NULL;
+       struct mdinfo *sra;
+       char *verstr;
+       char version[20];
+       int i;
+       char *subarray = NULL;
 
-       if (vers == 1) {
-               st->ss = &super1;
-               st->max_devs = 384;
+       sra = sysfs_read(fd, 0, GET_VERSION);
+
+       if (sra) {
+               vers = sra->array.major_version;
+               minor = sra->array.minor_version;
+               verstr = sra->text_version;
+       } else {
+               if (ioctl(fd, GET_ARRAY_INFO, &array))
+                       array.major_version = array.minor_version = 0;
+               vers = array.major_version;
+               minor = array.minor_version;
+               verstr = "";
+       }
+
+       if (vers != -1) {
+               sprintf(version, "%d.%d", vers, minor);
+               verstr = version;
+       }
+       if (minor == -2 && is_subarray(verstr)) {
+               char *dev = verstr+1;
+               subarray = strchr(dev, '/');
+               int devnum;
+               if (subarray)
+                       *subarray++ = '\0';
+               devnum = devname2devnum(dev);
+               subarray = strdup(subarray);
+               if (sra)
+                       sysfs_free(sra);
+               sra = sysfs_read(-1, devnum, GET_VERSION);
+               if (sra && sra->text_version[0])
+                       verstr = sra->text_version;
+               else
+                       verstr = "-no-metadata-";
+       }
+
+       for (i = 0; st == NULL && superlist[i] ; i++)
+               st = superlist[i]->match_metadata_desc(verstr);
+
+       if (sra)
+               sysfs_free(sra);
+       if (st) {
+               st->sb = NULL;
+               if (subarray) {
+                       strncpy(st->subarray, subarray, 32);
+                       st->subarray[31] = 0;
+                       free(subarray);
+               } else
+                       st->subarray[0] = 0;
        }
-       st->minor_version = minor;
+       return st;
+}
+#endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
+
+
+struct supertype *dup_super(struct supertype *orig)
+{
+       struct supertype *st;
+
+       if (!orig)
+               return orig;
+       st = malloc(sizeof(*st));
+       if (!st)
+               return st;
+       memset(st, 0, sizeof(*st));
+       st->ss = orig->ss;
+       st->max_devs = orig->max_devs;
+       st->minor_version = orig->minor_version;
+       strcpy(st->subarray, orig->subarray);
+       st->sb = NULL;
+       st->info = NULL;
        return st;
 }
 
@@ -750,34 +1036,31 @@ struct supertype *guess_super(int fd)
        struct supertype *st;
        unsigned long besttime = 0;
        int bestsuper = -1;
-
-       void *sbp = NULL;
        int i;
 
        st = malloc(sizeof(*st));
-       memset(st, 0, sizeof(*st));
        for (i=0 ; superlist[i]; i++) {
                int rv;
                ss = superlist[i];
-               st->ss = NULL;
-               rv = ss->load_super(st, fd, &sbp, NULL);
+               memset(st, 0, sizeof(*st));
+               rv = ss->load_super(st, fd, NULL);
                if (rv == 0) {
                        struct mdinfo info;
-                       ss->getinfo_super(&info, sbp);
+                       st->ss->getinfo_super(st, &info);
                        if (bestsuper == -1 ||
                            besttime < info.array.ctime) {
                                bestsuper = i;
                                besttime = info.array.ctime;
                        }
-                       free(sbp);
+                       ss->free_super(st);
                }
        }
        if (bestsuper != -1) {
                int rv;
-               st->ss = NULL;
-               rv = superlist[bestsuper]->load_super(st, fd, &sbp, NULL);
+               memset(st, 0, sizeof(*st));
+               rv = superlist[bestsuper]->load_super(st, fd, NULL);
                if (rv == 0) {
-                       free(sbp);
+                       superlist[bestsuper]->free_super(st);
                        return st;
                }
        }
@@ -789,6 +1072,11 @@ struct supertype *guess_super(int fd)
 int get_dev_size(int fd, char *dname, unsigned long long *sizep)
 {
        unsigned long long ldsize;
+       struct stat st;
+
+       if (fstat(fd, &st) != -1 && S_ISREG(st.st_mode))
+               ldsize = (unsigned long long)st.st_size;
+       else
 #ifdef BLKGETSIZE64
        if (ioctl(fd, BLKGETSIZE64, &ldsize) != 0)
 #endif
@@ -816,6 +1104,330 @@ void get_one_disk(int mdfd, mdu_array_info_t *ainf, mdu_disk_info_t *disk)
                if (ioctl(mdfd, GET_DISK_INFO, disk) == 0)
                        return;
 }
+
+int open_container(int fd)
+{
+       /* 'fd' is a block device.  Find out if it is in use
+        * by a container, and return an open fd on that container.
+        */
+       char path[256];
+       char *e;
+       DIR *dir;
+       struct dirent *de;
+       int dfd, n;
+       char buf[200];
+       int major, minor;
+       struct stat st;
+
+       if (fstat(fd, &st) != 0)
+               return -1;
+       sprintf(path, "/sys/dev/block/%d:%d/holders",
+               (int)major(st.st_rdev), (int)minor(st.st_rdev));
+       e = path + strlen(path);
+
+       dir = opendir(path);
+       if (!dir)
+               return -1;
+       while ((de = readdir(dir))) {
+               if (de->d_ino == 0)
+                       continue;
+               if (de->d_name[0] == '.')
+                       continue;
+               sprintf(e, "/%s/dev", de->d_name);
+               dfd = open(path, O_RDONLY);
+               if (dfd < 0)
+                       continue;
+               n = read(dfd, buf, sizeof(buf));
+               close(dfd);
+               if (n <= 0 || n >= sizeof(buf))
+                       continue;
+               buf[n] = 0;
+               if (sscanf(buf, "%d:%d", &major, &minor) != 2)
+                       continue;
+               sprintf(buf, "%d:%d", major, minor);
+               dfd = dev_open(buf, O_RDONLY);
+               if (dfd >= 0) {
+                       closedir(dir);
+                       return dfd;
+               }
+       }
+       closedir(dir);
+       return -1;
+}
+
+int add_disk(int mdfd, struct supertype *st,
+            struct mdinfo *sra, struct mdinfo *info)
+{
+       /* Add a device to an array, in one of 2 ways. */
+       int rv;
+#ifndef MDASSEMBLE
+       if (st->ss->external) {
+               if (info->disk.state & (1<<MD_DISK_SYNC))
+                       info->recovery_start = MaxSector;
+               else
+                       info->recovery_start = 0;
+               rv = sysfs_add_disk(sra, info);
+               if (! rv) {
+                       struct mdinfo *sd2;
+                       for (sd2 = sra->devs; sd2; sd2=sd2->next)
+                               if (sd2 == info)
+                                       break;
+                       if (sd2 == NULL) {
+                               sd2 = malloc(sizeof(*sd2));
+                               *sd2 = *info;
+                               sd2->next = sra->devs;
+                               sra->devs = sd2;
+                       }
+               }
+       } else
+#endif
+               rv = ioctl(mdfd, ADD_NEW_DISK, &info->disk);
+       return rv;
+}
+
+int set_array_info(int mdfd, struct supertype *st, struct mdinfo *info)
+{
+       /* Initialise kernel's knowledge of array.
+        * This varies between externally managed arrays
+        * and older kernels
+        */
+       int vers = md_get_version(mdfd);
+       int rv;
+
+#ifndef MDASSEMBLE
+       if (st->ss->external)
+               rv = sysfs_set_array(info, vers);
+       else
+#endif
+               if ((vers % 100) >= 1) { /* can use different versions */
+               mdu_array_info_t inf;
+               memset(&inf, 0, sizeof(inf));
+               inf.major_version = info->array.major_version;
+               inf.minor_version = info->array.minor_version;
+               rv = ioctl(mdfd, SET_ARRAY_INFO, &inf);
+       } else
+               rv = ioctl(mdfd, SET_ARRAY_INFO, NULL);
+       return rv;
+}
+
+char *devnum2devname(int num)
+{
+       char name[100];
+       if (num >= 0)
+               sprintf(name, "md%d", num);
+       else
+               sprintf(name, "md_d%d", -1-num);
+       return strdup(name);
+}
+
+int devname2devnum(char *name)
+{
+       char *ep;
+       int num;
+       if (strncmp(name, "md_d", 4)==0)
+               num = -1-strtoul(name+4, &ep, 10);
+       else
+               num = strtoul(name+2, &ep, 10);
+       return num;
+}
+
+int stat2devnum(struct stat *st)
+{
+       char path[30];
+       char link[200];
+       char *cp;
+       int n;
+
+       if ((S_IFMT & st->st_mode) == S_IFBLK) {
+               if (major(st->st_rdev) == MD_MAJOR)
+                       return minor(st->st_rdev);
+               else if (major(st->st_rdev) == get_mdp_major())
+                       return -1- (minor(st->st_rdev)>>MdpMinorShift);
+
+               /* must be an extended-minor partition. Look at the
+                * /sys/dev/block/%d:%d link which must look like
+                * ../../block/mdXXX/mdXXXpYY
+                */
+               sprintf(path, "/sys/dev/block/%d:%d", major(st->st_rdev),
+                       minor(st->st_rdev));
+               n = readlink(path, link, sizeof(link)-1);
+               if (n <= 0)
+                       return NoMdDev;
+               link[n] = 0;
+               cp = strrchr(link, '/');
+               if (cp) *cp = 0;
+               cp = strchr(link, '/');
+               if (cp && strncmp(cp, "/md", 3) == 0)
+                       return devname2devnum(cp+1);
+       }
+       return NoMdDev;
+
+}
+
+int fd2devnum(int fd)
+{
+       struct stat stb;
+       if (fstat(fd, &stb) == 0)
+               return stat2devnum(&stb);
+       return NoMdDev;
+}
+
+int mdmon_running(int devnum)
+{
+       char path[100];
+       char pid[10];
+       int fd;
+       int n;
+       sprintf(path, "/var/run/mdadm/%s.pid", devnum2devname(devnum));
+       fd = open(path, O_RDONLY, 0);
+
+       if (fd < 0)
+               return 0;
+       n = read(fd, pid, 9);
+       close(fd);
+       if (n <= 0)
+               return 0;
+       if (kill(atoi(pid), 0) == 0)
+               return 1;
+       return 0;
+}
+
+int signal_mdmon(int devnum)
+{
+       char path[100];
+       char pid[10];
+       int fd;
+       int n;
+       sprintf(path, "/var/run/mdadm/%s.pid", devnum2devname(devnum));
+       fd = open(path, O_RDONLY, 0);
+
+       if (fd < 0)
+               return 0;
+       n = read(fd, pid, 9);
+       close(fd);
+       if (n <= 0)
+               return 0;
+       if (kill(atoi(pid), SIGUSR1) == 0)
+               return 1;
+       return 0;
+}
+
+int start_mdmon(int devnum)
+{
+       int i;
+       int len;
+       pid_t pid;      
+       int status;
+       char pathbuf[1024];
+       char *paths[4] = {
+               pathbuf,
+               "/sbin/mdmon",
+               "mdmon",
+               NULL
+       };
+
+       if (check_env("MDADM_NO_MDMON"))
+               return 0;
+
+       len = readlink("/proc/self/exe", pathbuf, sizeof(pathbuf));
+       if (len > 0) {
+               char *sl;
+               pathbuf[len] = 0;
+               sl = strrchr(pathbuf, '/');
+               if (sl)
+                       sl++;
+               else
+                       sl = pathbuf;
+               strcpy(sl, "mdmon");
+       } else
+               pathbuf[0] = '\0';
+
+       switch(fork()) {
+       case 0:
+               /* FIXME yuk. CLOSE_EXEC?? */
+               for (i=3; i < 100; i++)
+                       close(i);
+               for (i=0; paths[i]; i++)
+                       if (paths[i][0])
+                               execl(paths[i], "mdmon",
+                                     devnum2devname(devnum),
+                                     NULL);
+               exit(1);
+       case -1: fprintf(stderr, Name ": cannot run mdmon. "
+                        "Array remains readonly\n");
+               return -1;
+       default: /* parent - good */
+               pid = wait(&status);
+               if (pid < 0 || status != 0)
+                       return -1;
+       }
+       return 0;
+}
+
+int check_env(char *name)
+{
+       char *val = getenv(name);
+
+       if (val && atoi(val) == 1)
+               return 1;
+
+       return 0;
+}
+
+__u32 random32(void)
+{
+       __u32 rv;
+       int rfd = open("/dev/urandom", O_RDONLY);
+       if (rfd < 0 || read(rfd, &rv, 4) != 4)
+               rv = random();
+       if (rfd >= 0)
+               close(rfd);
+       return rv;
+}
+
+#ifndef MDASSEMBLE
+int flush_metadata_updates(struct supertype *st)
+{
+       int sfd;
+       if (!st->updates) {
+               st->update_tail = NULL;
+               return -1;
+       }
+
+       sfd = connect_monitor(devnum2devname(st->container_dev));
+       if (sfd < 0)
+               return -1;
+
+       while (st->updates) {
+               struct metadata_update *mu = st->updates;
+               st->updates = mu->next;
+
+               send_message(sfd, mu, 0);
+               wait_reply(sfd, 0);
+               free(mu->buf);
+               free(mu);
+       }
+       ack(sfd, 0);
+       wait_reply(sfd, 0);
+       close(sfd);
+       st->update_tail = NULL;
+       return 0;
+}
+
+void append_metadata_update(struct supertype *st, void *buf, int len)
+{
+
+       struct metadata_update *mu = malloc(sizeof(*mu));
+
+       mu->buf = buf;
+       mu->len = len;
+       mu->space = NULL;
+       mu->next = NULL;
+       *st->update_tail = mu;
+       st->update_tail = &mu->next;
+}
+#endif /* MDASSEMBLE */
+
 #ifdef __TINYC__
 /* tinyc doesn't optimize this check in ioctl.h out ... */
 unsigned int __invalid_size_argument_for_IOC = 0;