btrfs-progs: convert: move init_btrfs
[btrfs-progs-unstable/devel.git] / super-recover.c
blob1dc3fc7d12e6f3c44f9711a569f2b722d54b265b
1 /*
2 * Copyright (C) 2013 FUJITSU LIMITED. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <fcntl.h>
22 #include <sys/stat.h>
23 #include <uuid/uuid.h>
24 #include <errno.h>
25 #include <unistd.h>
26 #include <ctype.h>
27 #include <getopt.h>
29 #include "kerncompat.h"
30 #include "ctree.h"
31 #include "disk-io.h"
32 #include "list.h"
33 #include "utils.h"
34 #include "crc32c.h"
35 #include "volumes.h"
36 #include "commands.h"
38 struct btrfs_recover_superblock {
39 struct btrfs_fs_devices *fs_devices;
41 struct list_head good_supers;
42 struct list_head bad_supers;
44 u64 max_generation;
47 struct super_block_record {
48 struct list_head list;
50 char *device_name;
51 struct btrfs_super_block sb;
53 u64 bytenr;
56 static
57 void init_recover_superblock(struct btrfs_recover_superblock *recover)
59 INIT_LIST_HEAD(&recover->good_supers);
60 INIT_LIST_HEAD(&recover->bad_supers);
62 recover->fs_devices = NULL;
63 recover->max_generation = 0;
66 static
67 void free_recover_superblock(struct btrfs_recover_superblock *recover)
69 struct super_block_record *record;
71 if (!recover->fs_devices)
72 return;
74 while (!list_empty(&recover->good_supers)) {
75 record = list_entry(recover->good_supers.next,
76 struct super_block_record, list);
77 list_del_init(&record->list);
78 free(record->device_name);
79 free(record);
82 while (!list_empty(&recover->bad_supers)) {
83 record = list_entry(recover->bad_supers.next,
84 struct super_block_record, list);
85 list_del_init(&record->list);
86 free(record->device_name);
87 free(record);
91 static int check_super(u64 bytenr, struct btrfs_super_block *sb)
93 int csum_size = btrfs_super_csum_size(sb);
94 char result[csum_size];
95 u32 crc = ~(u32)0;
97 if (btrfs_super_bytenr(sb) != bytenr)
98 return 0;
99 if (sb->magic != cpu_to_le64(BTRFS_MAGIC))
100 return 0;
102 crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE,
103 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
104 btrfs_csum_final(crc, result);
106 return !memcmp(sb, &result, csum_size);
109 static int add_superblock_record(struct btrfs_super_block *sb, char *fname,
110 u64 bytenr, struct list_head *head)
112 struct super_block_record *record;
114 record = malloc(sizeof(struct super_block_record));
115 if (!record)
116 return -ENOMEM;
118 record->device_name = strdup(fname);
119 if (!record->device_name) {
120 free(record);
121 return -ENOMEM;
123 memcpy(&record->sb, sb, sizeof(*sb));
124 record->bytenr = bytenr;
125 list_add_tail(&record->list, head);
127 return 0;
130 static int
131 read_dev_supers(char *filename, struct btrfs_recover_superblock *recover)
133 int i, ret, fd;
134 u8 buf[BTRFS_SUPER_INFO_SIZE];
135 u64 max_gen, bytenr;
136 /* just ignore errno that were set in btrfs_scan_fs_devices() */
137 errno = 0;
139 struct btrfs_super_block *sb = (struct btrfs_super_block *)buf;
141 fd = open(filename, O_RDONLY, 0666);
142 if (fd < 0)
143 return -errno;
145 for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
146 bytenr = btrfs_sb_offset(i);
147 ret = pread64(fd, buf, sizeof(buf), bytenr);
148 if (ret < sizeof(buf)) {
149 ret = -errno;
150 goto out;
152 ret = check_super(bytenr, sb);
153 if (ret) {
154 ret = add_superblock_record(sb, filename, bytenr,
155 &recover->good_supers);
156 if (ret)
157 goto out;
158 max_gen = btrfs_super_generation(sb);
159 if (max_gen > recover->max_generation)
160 recover->max_generation = max_gen;
161 } else {
162 ret = add_superblock_record(sb, filename, bytenr,
163 &recover->bad_supers);
164 if (ret)
165 goto out;
168 out:
169 close(fd);
170 return ret;
173 static int read_fs_supers(struct btrfs_recover_superblock *recover)
175 struct super_block_record *record;
176 struct super_block_record *next_record;
177 struct btrfs_device *dev;
178 int ret;
179 u64 gen;
181 list_for_each_entry(dev, &recover->fs_devices->devices,
182 dev_list) {
183 ret = read_dev_supers(dev->name, recover);
184 if (ret)
185 return ret;
187 list_for_each_entry_safe(record, next_record,
188 &recover->good_supers, list) {
189 gen = btrfs_super_generation(&record->sb);
190 if (gen < recover->max_generation)
191 list_move_tail(&record->list, &recover->bad_supers);
194 return 0;
197 static struct super_block_record *recover_get_good_super(
198 struct btrfs_recover_superblock *recover)
200 struct super_block_record *record;
201 record = list_entry(recover->good_supers.next,
202 struct super_block_record, list);
203 return record;
206 static void print_all_devices(struct list_head *devices)
208 struct btrfs_device *dev;
210 printf("All Devices:\n");
211 list_for_each_entry(dev, devices, dev_list) {
212 printf("\t");
213 printf("Device: id = %llu, name = %s\n",
214 dev->devid, dev->name);
216 printf("\n");
219 static void print_super_info(struct super_block_record *record)
221 printf("\t\tdevice name = %s\n", record->device_name);
222 printf("\t\tsuperblock bytenr = %llu\n", record->bytenr);
225 static void print_all_supers(struct btrfs_recover_superblock *recover)
227 struct super_block_record *record;
229 printf("\t[All good supers]:\n");
230 list_for_each_entry(record, &recover->good_supers, list) {
231 print_super_info(record);
232 printf("\n");
235 printf("\t[All bad supers]:\n");
236 list_for_each_entry(record, &recover->bad_supers, list) {
237 print_super_info(record);
238 printf("\n");
240 printf("\n");
243 static void recover_err_str(int ret)
245 switch (ret) {
246 case 0:
247 printf("All supers are valid, no need to recover\n");
248 break;
249 case 1:
250 printf("Usage or syntax errors\n");
251 break;
252 case 2:
253 printf("Recovered bad superblocks successful\n");
254 break;
255 case 3:
256 printf("Failed to recover bad superblocks\n");
257 break;
258 case 4:
259 printf("Aborted to recover bad superblocks\n");
260 break;
261 default:
262 printf("Unknown recover result\n");
263 break;
267 int btrfs_recover_superblocks(const char *dname,
268 int verbose, int yes)
270 int fd, ret;
271 struct btrfs_recover_superblock recover;
272 struct super_block_record *record;
273 struct btrfs_root *root = NULL;
275 fd = open(dname, O_RDONLY);
276 if (fd < 0) {
277 fprintf(stderr, "open %s error\n", dname);
278 return 1;
280 init_recover_superblock(&recover);
282 ret = btrfs_scan_fs_devices(fd, dname, &recover.fs_devices, 0,
283 SBREAD_RECOVER, 0);
284 close(fd);
285 if (ret) {
286 ret = 1;
287 goto no_recover;
290 if (verbose)
291 print_all_devices(&recover.fs_devices->devices);
293 ret = read_fs_supers(&recover);
294 if (ret) {
295 ret = 1;
296 goto no_recover;
298 if (verbose) {
299 printf("Before Recovering:\n");
300 print_all_supers(&recover);
303 if (list_empty(&recover.bad_supers))
304 goto no_recover;
306 if (!yes) {
307 ret = ask_user("Make sure this is a btrfs disk otherwise the tool will destroy other fs, Are you sure?");
308 if (!ret) {
309 ret = 4;
310 goto no_recover;
313 record = recover_get_good_super(&recover);
314 root = open_ctree(record->device_name, record->bytenr,
315 OPEN_CTREE_RECOVER_SUPER | OPEN_CTREE_WRITES);
316 if (!root) {
317 ret = 3;
318 goto no_recover;
320 /* reset super_bytenr in order that we will rewrite all supers */
321 root->fs_info->super_bytenr = BTRFS_SUPER_INFO_OFFSET;
322 ret = write_all_supers(root);
323 if (!ret)
324 ret = 2;
325 else
326 ret = 3;
328 close_ctree(root);
329 no_recover:
330 recover_err_str(ret);
331 free_recover_superblock(&recover);
332 /* check if we have freed fs_devices in close_ctree() */
333 if (!root)
334 btrfs_close_devices(recover.fs_devices);
335 return ret;