diff options
Diffstat (limited to 'Dump.c')
| -rw-r--r-- | Dump.c | 319 |
1 files changed, 319 insertions, 0 deletions
@@ -0,0 +1,319 @@ +/* + * mdadm - manage Linux "md" devices aka RAID arrays. + * + * Copyright (C) 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. + + * Author: Neil Brown + * Email: <neilb@suse.de> + */ + +#include "mdadm.h" +#include <sys/dir.h> + +int Dump_metadata(char *dev, char *dir, struct context *c, + struct supertype *st) +{ + /* create a new file in 'dir' named for the basename of 'dev'. + * Truncate to the same size as 'dev' and ask the metadata + * handler to copy metadata there. + * For every name in /dev/disk/by-id that points to this device, + * create a hardlink in 'dir'. + * Complain if any of those hardlinks cannot be created. + */ + int fd, fl; + struct stat stb, dstb; + char *base; + char *fname = NULL; + unsigned long long size; + DIR *dirp; + struct dirent *de; + + if (stat(dir, &stb) != 0 || + (S_IFMT & stb.st_mode) != S_IFDIR) { + pr_err("--dump requires an existing directory, not: %s\n", + dir); + return 16; + } + + fd = dev_open(dev, O_RDONLY); + if (fd < 0) { + pr_err("Cannot open %s to dump metadata: %s\n", + dev, strerror(errno)); + return 1; + } + if (!get_dev_size(fd, dev, &size)) { + close(fd); + return 1; + } + + if (st == NULL) + st = guess_super_type(fd, guess_array); + if (!st) { + pr_err("Cannot find RAID metadata on %s\n", dev); + close(fd); + return 1; + } + + st->ignore_hw_compat = 1; + if (st->ss->load_super(st, fd, NULL) != 0) { + pr_err("No %s metadata found on %s\n", + st->ss->name, dev); + close(fd); + return 1; + } + if (st->ss->copy_metadata == NULL) { + pr_err("%s metadata on %s cannot be copied\n", + st->ss->name, dev); + close(fd); + return 1; + } + + base = strrchr(dev, '/'); + if (base) + base++; + else + base = dev; + xasprintf(&fname, "%s/%s", dir, base); + fl = open(fname, O_RDWR|O_CREAT|O_EXCL, 0666); + if (fl < 0) { + pr_err("Cannot create dump file %s: %s\n", + fname, strerror(errno)); + close(fd); + free(fname); + return 1; + } + if (ftruncate(fl, size) < 0) { + pr_err("failed to set size of dump file: %s\n", + strerror(errno)); + close(fd); + close(fl); + free(fname); + return 1; + } + + if (st->ss->copy_metadata(st, fd, fl) != 0) { + pr_err("Failed to copy metadata from %s to %s\n", + dev, fname); + close(fd); + close(fl); + unlink(fname); + free(fname); + return 1; + } + if (c->verbose >= 0) + printf("%s saved as %s.\n", dev, fname); + fstat(fd, &dstb); + close(fd); + close(fl); + if ((dstb.st_mode & S_IFMT) != S_IFBLK) { + /* Not a block device, so cannot create links */ + free(fname); + return 0; + } + /* mostly done: just want to find some other names */ + dirp = opendir("/dev/disk/by-id"); + if (!dirp) { + free(fname); + return 0; + } + while ((de = readdir(dirp)) != NULL) { + char *p = NULL; + if (de->d_name[0] == '.') + continue; + xasprintf(&p, "/dev/disk/by-id/%s", de->d_name); + if (stat(p, &stb) != 0 || + (stb.st_mode & S_IFMT) != S_IFBLK || + stb.st_rdev != dstb.st_rdev) { + /* Not this one */ + free(p); + continue; + } + free(p); + xasprintf(&p, "%s/%s", dir, de->d_name); + if (link(fname, p) == 0) { + if (c->verbose >= 0) + printf("%s also saved as %s.\n", + dev, p); + } else { + pr_err("Could not save %s as %s!!\n", + dev, p); + } + free(p); + } + closedir(dirp); + free(fname); + return 0; +} + +int Restore_metadata(char *dev, char *dir, struct context *c, + struct supertype *st, int only) +{ + /* If 'dir' really is a directory we choose a name + * from it that matches a suitable name in /dev/disk/by-id, + * and copy metadata from the file to the device. + * If two names from by-id match and aren't both the same + * inode, we fail. If none match and basename of 'dev' + * can be found in dir, use that. + * If 'dir' is really a file then it is only permitted if + * 'only' is set (meaning there was only one device given) + * and the metadata is restored irrespective of file names. + */ + int fd, fl; + struct stat stb, dstb; + char *fname = NULL; + unsigned long long size; + + if (stat(dir, &stb) != 0) { + pr_err("%s does not exist: cannot restore from there.\n", + dir); + return 16; + } else if ((S_IFMT & stb.st_mode) != S_IFDIR && !only) { + pr_err("--restore requires a directory when multiple devices given\n"); + return 16; + } + + fd = dev_open(dev, O_RDWR); + if (fd < 0) { + pr_err("Cannot open %s to restore metadata: %s\n", + dev, strerror(errno)); + return 1; + } + if (!get_dev_size(fd, dev, &size)) { + close(fd); + return 1; + } + + if ((S_IFMT & stb.st_mode) == S_IFDIR) { + /* choose one name from the directory. */ + DIR *d = opendir(dir); + struct dirent *de; + char *chosen = NULL; + unsigned int chosen_inode = 0; + + fstat(fd, &dstb); + + while (d && (de = readdir(d)) != NULL) { + if (de->d_name[0] == '.') + continue; + xasprintf(&fname, "/dev/disk/by-id/%s", de->d_name); + if (stat(fname, &stb) != 0) { + free(fname); + continue; + } + free(fname); + if ((S_IFMT & stb.st_mode) != S_IFBLK) + continue; + if (stb.st_rdev != dstb.st_rdev) + continue; + /* This file is a good match for our device. */ + xasprintf(&fname, "%s/%s", dir, de->d_name); + if (stat(fname, &stb) != 0) { + /* Weird! */ + free(fname); + continue; + } + if (chosen == NULL) { + chosen = fname; + chosen_inode = stb.st_ino; + continue; + } + if (chosen_inode == stb.st_ino) { + /* same, no need to change */ + free(fname); + continue; + } + /* Oh dear, two names both match. Must give up. */ + pr_err("Both %s and %s seem suitable for %s. Please choose one.\n", + chosen, fname, dev); + free(fname); + free(chosen); + close(fd); + closedir(d); + return 1; + } + closedir(d); + if (!chosen) { + /* One last chance: try basename of device */ + char *base = strrchr(dev, '/'); + if (base) + base++; + else + base = dev; + xasprintf(&fname, "%s/%s", dir, base); + if (stat(fname, &stb) == 0) + chosen = fname; + else + free(fname); + } + fname = chosen; + } else + fname = strdup(dir); + + if (!fname) { + pr_err("Cannot find suitable file in %s for %s\n", + dir, dev); + close(fd); + return 1; + } + + fl = open(fname, O_RDONLY); + if (!fl) { + pr_err("Could not open %s for --restore.\n", + fname); + goto err; + } + if (stat(fname, &stb) != 0) { + pr_err("Could not stat %s for --restore.\n", + fname); + goto err; + } + if (((unsigned long long)stb.st_size) != size) { + pr_err("%s is not the same size as %s - cannot restore.\n", + fname, dev); + goto err; + } + if (st == NULL) + st = guess_super_type(fl, guess_array); + if (!st) { + pr_err("Cannot find metadata on %s\n", fname); + goto err; + } + st->ignore_hw_compat = 1; + if (st->ss->load_super(st, fl, NULL) != 0) { + pr_err("No %s metadata found on %s\n", + st->ss->name, fname); + goto err; + } + if (st->ss->copy_metadata == NULL) { + pr_err("%s metadata on %s cannot be copied\n", + st->ss->name, dev); + goto err; + } + if (st->ss->copy_metadata(st, fl, fd) != 0) { + pr_err("Failed to copy metadata from %s to %s\n", + fname, dev); + goto err; + } + if (c->verbose >= 0) + printf("%s restored from %s.\n", dev, fname); + close(fl); + close(fd); + free(fname); + return 0; + +err: + close(fd); + close(fl); + free(fname); + return 1; +} |