From 946b54554e13d6a97940df936123855e0a305abc Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 24 Feb 2023 15:34:34 +0100 Subject: Adding upstream version 4.2. Signed-off-by: Daniel Baumann --- mdopen.c | 509 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 509 insertions(+) create mode 100644 mdopen.c (limited to 'mdopen.c') diff --git a/mdopen.c b/mdopen.c new file mode 100644 index 0000000..245be53 --- /dev/null +++ b/mdopen.c @@ -0,0 +1,509 @@ +/* + * mdadm - manage Linux "md" devices aka RAID arrays. + * + * Copyright (C) 2001-2013 Neil Brown + * + * + * 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: + */ + +#include "mdadm.h" +#include "md_p.h" +#include + +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[1001]; + 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; + + len = readlink(dev, orig, sizeof(orig)); + if (len < 0 || len >= (int)sizeof(orig)) + 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); +} + +int create_named_array(char *devnm) +{ + int fd; + int n = -1; + static const char new_array_file[] = { + "/sys/module/md_mod/parameters/new_array" + }; + + fd = open(new_array_file, O_WRONLY); + if (fd < 0 && errno == ENOENT) { + if (system("modprobe md_mod") == 0) + fd = open(new_array_file, O_WRONLY); + } + if (fd >= 0) { + n = write(fd, devnm, strlen(devnm)); + close(fd); + } + if (fd < 0 || n != (int)strlen(devnm)) { + pr_err("Fail to create %s when using %s, fallback to creation via node\n", + devnm, new_array_file); + return 0; + } + + return 1; +} + +/* + * 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 block_udev) +{ + 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[37]; + char devnm[32]; + char cbuf[400]; + + if (!use_udev()) + block_udev = 0; + + 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!).\n", 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) { + sprintf(devnm, "md_%s", cname); + if (block_udev) + udev_block(devnm); + if (!create_named_array(devnm)) { + devnm[0] = 0; + udev_unblock(); + } + } + if (num >= 0) { + sprintf(devnm, "md%d", num); + if (block_udev) + udev_block(devnm); + if (!create_named_array(devnm)) { + devnm[0] = 0; + udev_unblock(); + } + } + if (devnm[0] == 0) { + 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; + } + } + if (block_udev) + udev_block(devnm); + } + + 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 != 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_RDONLY); + + if (mdfd < 0) { + if (report_errors) + pr_err("error opening %s: %s\n", + dev, strerror(errno)); + return -1; + } + + if (md_array_valid(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<<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; +} -- cgit v1.2.3