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-rw-r--r--mdopen.c468
1 files changed, 468 insertions, 0 deletions
diff --git a/mdopen.c b/mdopen.c
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--- /dev/null
+++ b/mdopen.c
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+/*
+ * mdadm - manage Linux "md" devices aka RAID arrays.
+ *
+ * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Neil Brown
+ * Email: <neilb@suse.de>
+ */
+
+#include "mdadm.h"
+#include "md_p.h"
+#include <ctype.h>
+
+void make_parts(char *dev, int cnt)
+{
+ /* make 'cnt' partition devices for 'dev'
+ * If dev is a device name we use the
+ * major/minor from dev and add 1..cnt
+ * If it is a symlink, we make similar symlinks.
+ * If dev ends with a digit, we add "p%d" else "%d"
+ * If the name exists, we use it's owner/mode,
+ * else that of dev
+ */
+ struct stat stb;
+ int major_num;
+ int minor_num;
+ int odig;
+ int i;
+ int nlen = strlen(dev) + 20;
+ char *name;
+ int dig = isdigit(dev[strlen(dev)-1]);
+ char orig[1024];
+ char sym[1024];
+ int err;
+
+ if (cnt == 0)
+ cnt = 4;
+ if (lstat(dev, &stb)!= 0)
+ return;
+
+ if (S_ISBLK(stb.st_mode)) {
+ major_num = major(stb.st_rdev);
+ minor_num = minor(stb.st_rdev);
+ odig = -1;
+ } else if (S_ISLNK(stb.st_mode)) {
+ int len = readlink(dev, orig, sizeof(orig));
+ if (len < 0 || len > 1000)
+ return;
+ orig[len] = 0;
+ odig = isdigit(orig[len-1]);
+ major_num = -1;
+ minor_num = -1;
+ } else
+ return;
+ name = xmalloc(nlen);
+ for (i = 1; i <= cnt ; i++) {
+ struct stat stb2;
+ snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
+ if (stat(name, &stb2) == 0) {
+ if (!S_ISBLK(stb2.st_mode) || !S_ISBLK(stb.st_mode))
+ continue;
+ if (stb2.st_rdev == makedev(major_num, minor_num+i))
+ continue;
+ unlink(name);
+ } else {
+ stb2 = stb;
+ }
+ if (S_ISBLK(stb.st_mode)) {
+ if (mknod(name, S_IFBLK | 0600,
+ makedev(major_num, minor_num+i)))
+ perror("mknod");
+ if (chown(name, stb2.st_uid, stb2.st_gid))
+ perror("chown");
+ if (chmod(name, stb2.st_mode & 07777))
+ perror("chmod");
+ err = 0;
+ } else {
+ snprintf(sym, sizeof(sym), "%s%s%d", orig, odig?"p":"", i);
+ err = symlink(sym, name);
+ }
+
+ if (err == 0 && stat(name, &stb2) == 0)
+ add_dev(name, &stb2, 0, NULL);
+ }
+ free(name);
+}
+
+/*
+ * We need a new md device to assemble/build/create an array.
+ * 'dev' is a name given us by the user (command line or mdadm.conf)
+ * It might start with /dev or /dev/md any might end with a digit
+ * string.
+ * If it starts with just /dev, it must be /dev/mdX or /dev/md_dX
+ * If it ends with a digit string, then it must be as above, or
+ * 'trustworthy' must be 'METADATA' and the 'dev' must be
+ * /dev/md/'name'NN or 'name'NN
+ * If it doesn't end with a digit string, it must be /dev/md/'name'
+ * or 'name' or must be NULL.
+ * If the digit string is present, it gives the minor number to use
+ * If not, we choose a high, unused minor number.
+ * If the 'dev' is a standard name, it devices whether 'md' or 'mdp'.
+ * else if the name is 'd[0-9]+' then we use mdp
+ * else if trustworthy is 'METADATA' we use md
+ * else the choice depends on 'autof'.
+ * If name is NULL it is assumed to match whatever dev provides.
+ * If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX'
+ *
+ * If 'name' is given, and 'trustworthy' is 'foreign' and name is not
+ * supported by 'dev', we add a "_%d" suffix based on the minor number
+ * use that.
+ *
+ * If udev is configured, we create a temporary device, open it, and
+ * unlink it.
+ * If not, we create the /dev/mdXX device, and if name is usable,
+ * /dev/md/name
+ * In any case we return /dev/md/name or (if that isn't available)
+ * /dev/mdXX in 'chosen'.
+ *
+ * When we create devices, we use uid/gid/umask from config file.
+ */
+
+int create_mddev(char *dev, char *name, int autof, int trustworthy,
+ char *chosen)
+{
+ int mdfd;
+ struct stat stb;
+ int num = -1;
+ int use_mdp = -1;
+ struct createinfo *ci = conf_get_create_info();
+ int parts;
+ char *cname;
+ char devname[20];
+ char devnm[32];
+ char cbuf[400];
+ if (chosen == NULL)
+ chosen = cbuf;
+
+ if (autof == 0)
+ autof = ci->autof;
+
+ parts = autof >> 3;
+ autof &= 7;
+
+ strcpy(chosen, "/dev/md/");
+ cname = chosen + strlen(chosen);
+
+ if (dev) {
+ if (strncmp(dev, "/dev/md/", 8) == 0) {
+ strcpy(cname, dev+8);
+ } else if (strncmp(dev, "/dev/", 5) == 0) {
+ char *e = dev + strlen(dev);
+ while (e > dev && isdigit(e[-1]))
+ e--;
+ if (e[0])
+ num = strtoul(e, NULL, 10);
+ strcpy(cname, dev+5);
+ cname[e-(dev+5)] = 0;
+ /* 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",
+ dev, dev+5);
+ return -1;
+ }
+ if (strcmp(cname, "md") == 0)
+ use_mdp = 0;
+ else
+ use_mdp = 1;
+ /* recreate name: /dev/md/0 or /dev/md/d0 */
+ sprintf(cname, "%s%d", use_mdp?"d":"", num);
+ } else
+ strcpy(cname, dev);
+
+ /* 'cname' must not contain a slash, and may not be
+ * empty.
+ */
+ if (strchr(cname, '/') != NULL) {
+ 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);
+ return -1;
+ }
+ if (num < 0) {
+ /* If cname is 'N' or 'dN', we get dev number
+ * from there.
+ */
+ char *sp = cname;
+ char *ep;
+ if (cname[0] == 'd')
+ sp++;
+ if (isdigit(sp[0]))
+ num = strtoul(sp, &ep, 10);
+ else
+ ep = sp;
+ if (ep == sp || *ep || num < 0)
+ num = -1;
+ else if (cname[0] == 'd')
+ use_mdp = 1;
+ else
+ use_mdp = 0;
+ }
+ }
+
+ /* Now determine device number */
+ /* named 'METADATA' cannot use 'mdp'. */
+ 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);
+ return -1;
+ }
+ if (name && trustworthy == METADATA)
+ use_mdp = 0;
+ if (use_mdp == -1) {
+ if (autof == 4 || autof == 6)
+ use_mdp = 1;
+ else
+ use_mdp = 0;
+ }
+ if (num < 0 && trustworthy == LOCAL && name) {
+ /* if name is numeric, possibly prefixed by
+ * 'md' or '/dev/md', use that for num
+ * if it is not already in use */
+ char *ep;
+ char *n2 = name;
+ if (strncmp(n2, "/dev/", 5) == 0)
+ n2 += 5;
+ if (strncmp(n2, "md", 2) == 0)
+ n2 += 2;
+ if (*n2 == '/')
+ n2++;
+ num = strtoul(n2, &ep, 10);
+ if (ep == n2 || *ep)
+ num = -1;
+ else {
+ sprintf(devnm, "md%s%d", use_mdp ? "_d":"", num);
+ if (mddev_busy(devnm))
+ num = -1;
+ }
+ }
+
+ if (cname[0] == 0 && name) {
+ /* Need to find a name if we can
+ * We don't completely trust 'name'. Truncate to
+ * reasonable length and remove '/'
+ */
+ char *cp;
+ struct map_ent *map = NULL;
+ int conflict = 1;
+ int unum = 0;
+ int cnlen;
+ strncpy(cname, name, 200);
+ cname[200] = 0;
+ for (cp = cname; *cp ; cp++)
+ switch (*cp) {
+ case '/':
+ *cp = '-';
+ break;
+ case ' ':
+ case '\t':
+ *cp = '_';
+ break;
+ }
+
+ if (trustworthy == LOCAL ||
+ (trustworthy == FOREIGN && strchr(cname, ':') != NULL)) {
+ /* Only need suffix if there is a conflict */
+ if (map_by_name(&map, cname) == NULL)
+ conflict = 0;
+ }
+ cnlen = strlen(cname);
+ while (conflict) {
+ if (trustworthy == METADATA && !isdigit(cname[cnlen-1]))
+ sprintf(cname+cnlen, "%d", unum);
+ else
+ /* add _%d to FOREIGN array that don't
+ * a 'host:' prefix
+ */
+ sprintf(cname+cnlen, "_%d", unum);
+ unum++;
+ if (map_by_name(&map, cname) == NULL)
+ conflict = 0;
+ }
+ }
+
+ devnm[0] = 0;
+ if (num < 0 && cname && ci->names) {
+ int fd;
+ int n = -1;
+ sprintf(devnm, "md_%s", cname);
+ fd = open("/sys/module/md_mod/parameters/new_array", O_WRONLY);
+ if (fd >= 0) {
+ n = write(fd, devnm, strlen(devnm));
+ close(fd);
+ }
+ if (n < 0)
+ devnm[0] = 0;
+ }
+ if (devnm[0])
+ ;
+ else if (num < 0) {
+ /* need to choose a free number. */
+ char *_devnm = find_free_devnm(use_mdp);
+ if (devnm == NULL) {
+ pr_err("No avail md devices - aborting\n");
+ return -1;
+ }
+ strcpy(devnm, _devnm);
+ } else {
+ sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num);
+ if (mddev_busy(devnm)) {
+ pr_err("%s is already in use.\n",
+ dev);
+ return -1;
+ }
+ }
+
+ sprintf(devname, "/dev/%s", devnm);
+
+ if (dev && dev[0] == '/')
+ strcpy(chosen, dev);
+ else if (cname[0] == 0)
+ strcpy(chosen, devname);
+
+ /* We have a device number and name.
+ * If we cannot detect udev, we need to make
+ * devices and links ourselves.
+ */
+ if (!use_udev()) {
+ /* Make sure 'devname' exists and 'chosen' is a symlink to it */
+ 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)) {
+ pr_err("%s exists but looks wrong, please fix\n",
+ devname);
+ return -1;
+ }
+ } else {
+ if (mknod(devname, S_IFBLK|0600,
+ devnm2devid(devnm)) != 0) {
+ pr_err("failed to create %s\n",
+ devname);
+ return -1;
+ }
+ if (chown(devname, ci->uid, ci->gid))
+ perror("chown");
+ if (chmod(devname, ci->mode))
+ perror("chmod");
+ stat(devname, &stb);
+ add_dev(devname, &stb, 0, NULL);
+ }
+ if (use_mdp == 1)
+ make_parts(devname, parts);
+
+ if (strcmp(chosen, devname) != 0) {
+ if (mkdir("/dev/md",0700) == 0) {
+ if (chown("/dev/md", ci->uid, ci->gid))
+ perror("chown /dev/md");
+ if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
+ perror("chmod /dev/md");
+ }
+
+ if (dev && strcmp(chosen, dev) == 0)
+ /* We know we are allowed to use this name */
+ unlink(chosen);
+
+ if (lstat(chosen, &stb) == 0) {
+ char buf[300];
+ ssize_t link_len = readlink(chosen, buf, sizeof(buf)-1);
+ if (link_len >= 0)
+ buf[link_len] = '\0';
+
+ if ((stb.st_mode & S_IFMT) != S_IFLNK ||
+ link_len < 0 ||
+ strcmp(buf, devname) != 0) {
+ pr_err("%s exists - ignoring\n",
+ chosen);
+ strcpy(chosen, devname);
+ }
+ } else if (symlink(devname, chosen) != 0)
+ pr_err("failed to create %s: %s\n",
+ chosen, strerror(errno));
+ if (use_mdp && strcmp(chosen, devname) != 0)
+ make_parts(chosen, parts);
+ }
+ }
+ mdfd = open_dev_excl(devnm);
+ if (mdfd < 0)
+ pr_err("unexpected failure opening %s\n",
+ devname);
+ return mdfd;
+}
+
+/* Open this and check that it is an md device.
+ * On success, return filedescriptor.
+ * On failure, return -1 if it doesn't exist,
+ * or -2 if it exists but is not an md device.
+ */
+int open_mddev(char *dev, int report_errors)
+{
+ int mdfd = open(dev, O_RDWR);
+ if (mdfd < 0 && errno == EACCES)
+ mdfd = open(dev, O_RDONLY);
+ if (mdfd < 0) {
+ if (report_errors)
+ pr_err("error opening %s: %s\n",
+ dev, strerror(errno));
+ return -1;
+ }
+ if (md_get_version(mdfd) <= 0) {
+ close(mdfd);
+ if (report_errors)
+ 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<<20)-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 */
+ int 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;
+}
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