btrfs-progs/super-recover.c
Nikolay Borisov 4487aa64e7 btrfs-progs: super-recover: fix the broken sb detection
Commit 3296d058b7 ("btrfs-progs: super-recover: Reuse
 btrfs_read_dev_super function") changed the logic when a superblock
is added to the bad block list to depend on -EIO. However currently
btrfs_read_dev_super doesn't return -EIO when the fist super block
is broken. Instead it returns -1. This causes the super-recovery
logic to miss the fact that the first super block is completely broken.

Fix this by considering any error code from btrfs_read_dev_super other
than -ENOENT to mean that the super block is corrupted. -ENOENT
means that the superblock copy is not part of the fs i.e. it's smaller
than the offset of the block. This can only occur for the 2nd copy at
256gb mark.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-31 15:14:01 +01:00

301 lines
6.7 KiB
C

/*
* Copyright (C) 2013 FUJITSU LIMITED. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* 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 021110-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <uuid/uuid.h>
#include <errno.h>
#include <unistd.h>
#include <ctype.h>
#include <getopt.h>
#include "kerncompat.h"
#include "ctree.h"
#include "disk-io.h"
#include "list.h"
#include "utils.h"
#include "crc32c.h"
#include "volumes.h"
#include "commands.h"
struct btrfs_recover_superblock {
struct btrfs_fs_devices *fs_devices;
struct list_head good_supers;
struct list_head bad_supers;
u64 max_generation;
};
struct super_block_record {
struct list_head list;
char *device_name;
struct btrfs_super_block sb;
u64 bytenr;
};
static
void init_recover_superblock(struct btrfs_recover_superblock *recover)
{
INIT_LIST_HEAD(&recover->good_supers);
INIT_LIST_HEAD(&recover->bad_supers);
recover->fs_devices = NULL;
recover->max_generation = 0;
}
static
void free_recover_superblock(struct btrfs_recover_superblock *recover)
{
struct super_block_record *record;
if (!recover->fs_devices)
return;
while (!list_empty(&recover->good_supers)) {
record = list_entry(recover->good_supers.next,
struct super_block_record, list);
list_del_init(&record->list);
free(record->device_name);
free(record);
}
while (!list_empty(&recover->bad_supers)) {
record = list_entry(recover->bad_supers.next,
struct super_block_record, list);
list_del_init(&record->list);
free(record->device_name);
free(record);
}
}
static int add_superblock_record(struct btrfs_super_block *sb, char *fname,
u64 bytenr, struct list_head *head)
{
struct super_block_record *record;
record = malloc(sizeof(struct super_block_record));
if (!record)
return -ENOMEM;
record->device_name = strdup(fname);
if (!record->device_name) {
free(record);
return -ENOMEM;
}
memcpy(&record->sb, sb, sizeof(*sb));
record->bytenr = bytenr;
list_add_tail(&record->list, head);
return 0;
}
static int
read_dev_supers(char *filename, struct btrfs_recover_superblock *recover)
{
int i, ret, fd;
u8 buf[BTRFS_SUPER_INFO_SIZE];
u64 max_gen, bytenr;
struct btrfs_super_block *sb = (struct btrfs_super_block *)buf;
/* just ignore errno that were set in btrfs_scan_fs_devices() */
errno = 0;
fd = open(filename, O_RDONLY);
if (fd < 0)
return -errno;
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
ret = btrfs_read_dev_super(fd, sb, bytenr, SBREAD_DEFAULT);
if (!ret) {
ret = add_superblock_record(sb, filename, bytenr,
&recover->good_supers);
if (ret)
goto out;
max_gen = btrfs_super_generation(sb);
if (max_gen > recover->max_generation)
recover->max_generation = max_gen;
} else if (ret != -ENOENT){
/*
* Skip superblock which doesn't exist, only adds
* really corrupted superblock
*/
ret = add_superblock_record(sb, filename, bytenr,
&recover->bad_supers);
if (ret)
goto out;
}
}
ret = 0;
out:
close(fd);
return ret;
}
static int read_fs_supers(struct btrfs_recover_superblock *recover)
{
struct super_block_record *record;
struct super_block_record *next_record;
struct btrfs_device *dev;
int ret;
u64 gen;
list_for_each_entry(dev, &recover->fs_devices->devices,
dev_list) {
ret = read_dev_supers(dev->name, recover);
if (ret)
return ret;
}
list_for_each_entry_safe(record, next_record,
&recover->good_supers, list) {
gen = btrfs_super_generation(&record->sb);
if (gen < recover->max_generation)
list_move_tail(&record->list, &recover->bad_supers);
}
return 0;
}
static void print_super_info(struct super_block_record *record)
{
printf("\t\tdevice name = %s\n", record->device_name);
printf("\t\tsuperblock bytenr = %llu\n", record->bytenr);
}
static void print_all_supers(struct btrfs_recover_superblock *recover)
{
struct super_block_record *record;
printf("\t[All good supers]:\n");
list_for_each_entry(record, &recover->good_supers, list) {
print_super_info(record);
printf("\n");
}
printf("\t[All bad supers]:\n");
list_for_each_entry(record, &recover->bad_supers, list) {
print_super_info(record);
printf("\n");
}
printf("\n");
}
static void recover_err_str(int ret)
{
switch (ret) {
case 0:
printf("All supers are valid, no need to recover\n");
break;
case 1:
printf("Usage or syntax errors\n");
break;
case 2:
printf("Recovered bad superblocks successful\n");
break;
case 3:
printf("Failed to recover bad superblocks\n");
break;
case 4:
printf("Aborted to recover bad superblocks\n");
break;
default:
printf("Unknown recover result\n");
break;
}
}
int btrfs_recover_superblocks(const char *dname,
int verbose, int yes)
{
int fd, ret;
struct btrfs_recover_superblock recover;
struct super_block_record *record;
struct btrfs_root *root = NULL;
fd = open(dname, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "open %s error\n", dname);
return 1;
}
init_recover_superblock(&recover);
ret = btrfs_scan_fs_devices(fd, dname, &recover.fs_devices, 0,
SBREAD_RECOVER, 0);
close(fd);
if (ret) {
ret = 1;
goto no_recover;
}
if (verbose)
print_all_devices(&recover.fs_devices->devices);
ret = read_fs_supers(&recover);
if (ret) {
ret = 1;
goto no_recover;
}
if (verbose) {
printf("Before Recovering:\n");
print_all_supers(&recover);
}
if (list_empty(&recover.bad_supers))
goto no_recover;
if (!yes) {
ret = ask_user("Make sure this is a btrfs disk otherwise the tool will destroy other fs, Are you sure?");
if (!ret) {
ret = 4;
goto no_recover;
}
}
record = list_first_entry(&recover.good_supers,
struct super_block_record, list);
root = open_ctree(record->device_name, record->bytenr,
OPEN_CTREE_RECOVER_SUPER | OPEN_CTREE_WRITES);
if (!root) {
ret = 3;
goto no_recover;
}
/* reset super_bytenr in order that we will rewrite all supers */
root->fs_info->super_bytenr = BTRFS_SUPER_INFO_OFFSET;
ret = write_all_supers(root->fs_info);
if (!ret)
ret = 2;
else
ret = 3;
close_ctree(root);
no_recover:
recover_err_str(ret);
free_recover_superblock(&recover);
/* check if we have freed fs_devices in close_ctree() */
if (!root)
btrfs_close_devices(recover.fs_devices);
return ret;
}