Dump.c - pub/scm/utils/mdadm/mdadm - Git at Google

 /*
  * 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;
 }
	/*
	* 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;
	}