btrfs-progs/btrfstune.c

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/*
* Copyright (C) 2008 Oracle. 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 <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include "kerncompat.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "utils.h"
static char *device;
static int force = 0;
static int update_seeding_flag(struct btrfs_root *root, int set_flag)
{
struct btrfs_trans_handle *trans;
struct btrfs_super_block *disk_super;
u64 super_flags;
disk_super = root->fs_info->super_copy;
super_flags = btrfs_super_flags(disk_super);
if (set_flag) {
if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
if (force)
return 0;
else
fprintf(stderr, "seeding flag is already set on %s\n", device);
return 1;
}
super_flags |= BTRFS_SUPER_FLAG_SEEDING;
} else {
if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
fprintf(stderr, "seeding flag is not set on %s\n",
device);
return 1;
}
super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
fprintf(stderr, "Warning: Seeding flag cleared.\n");
}
trans = btrfs_start_transaction(root, 1);
btrfs_set_super_flags(disk_super, super_flags);
btrfs_commit_transaction(trans, root);
return 0;
}
static int enable_extrefs_flag(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
struct btrfs_super_block *disk_super;
u64 super_flags;
disk_super = root->fs_info->super_copy;
super_flags = btrfs_super_incompat_flags(disk_super);
super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
trans = btrfs_start_transaction(root, 1);
btrfs_set_super_incompat_flags(disk_super, super_flags);
btrfs_commit_transaction(trans, root);
return 0;
}
static int enable_skinny_metadata(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
struct btrfs_super_block *disk_super;
u64 super_flags;
disk_super = root->fs_info->super_copy;
super_flags = btrfs_super_incompat_flags(disk_super);
super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
trans = btrfs_start_transaction(root, 1);
btrfs_set_super_incompat_flags(disk_super, super_flags);
btrfs_commit_transaction(trans, root);
return 0;
}
static int change_header_uuid(struct btrfs_root *root, struct extent_buffer *eb)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int same_fsid = 1;
int same_chunk_tree_uuid = 1;
int ret;
/* Check for whether we need to change fs/chunk id */
if (!fs_info->new_fsid && !fs_info->new_chunk_tree_uuid)
return 0;
if (fs_info->new_fsid)
same_fsid = !memcmp_extent_buffer(eb, fs_info->new_fsid,
btrfs_header_fsid(), BTRFS_FSID_SIZE);
if (fs_info->new_chunk_tree_uuid)
same_chunk_tree_uuid =
!memcmp_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
btrfs_header_chunk_tree_uuid(eb),
BTRFS_UUID_SIZE);
if (same_fsid && same_chunk_tree_uuid)
return 0;
if (!same_fsid)
write_extent_buffer(eb, fs_info->new_fsid, btrfs_header_fsid(),
BTRFS_FSID_SIZE);
if (!same_chunk_tree_uuid)
write_extent_buffer(eb, fs_info->new_chunk_tree_uuid,
btrfs_header_chunk_tree_uuid(eb),
BTRFS_UUID_SIZE);
ret = write_tree_block(NULL, root, eb);
return ret;
}
static void print_usage(void)
{
fprintf(stderr, "usage: btrfstune [options] device\n");
fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
fprintf(stderr, "\t-f \t\tforce to set or clear flags, make sure that you are aware of the dangers\n");
}
int main(int argc, char *argv[])
{
struct btrfs_root *root;
int success = 0;
int total = 0;
int extrefs_flag = 0;
int seeding_flag = 0;
u64 seeding_value = 0;
int skinny_flag = 0;
int ret;
optind = 1;
while(1) {
int c = getopt(argc, argv, "S:rxf");
if (c < 0)
break;
switch(c) {
case 'S':
seeding_flag = 1;
seeding_value = arg_strtou64(optarg);
break;
case 'r':
extrefs_flag = 1;
break;
case 'x':
skinny_flag = 1;
break;
case 'f':
force = 1;
break;
default:
print_usage();
return 1;
}
}
set_argv0(argv);
argc = argc - optind;
device = argv[optind];
if (check_argc_exact(argc, 1)) {
print_usage();
return 1;
}
if (!(seeding_flag + extrefs_flag + skinny_flag)) {
fprintf(stderr,
"ERROR: At least one option should be assigned.\n");
print_usage();
return 1;
}
ret = check_mounted(device);
if (ret < 0) {
fprintf(stderr, "Could not check mount status: %s\n",
strerror(-ret));
return 1;
} else if (ret) {
fprintf(stderr, "%s is mounted\n", device);
return 1;
}
root = open_ctree(device, 0, OPEN_CTREE_WRITES);
if (!root) {
fprintf(stderr, "Open ctree failed\n");
return 1;
}
if (seeding_flag) {
if (!seeding_value && !force) {
fprintf(stderr, "Warning: This is dangerous, clearing the seeding flag may cause the derived device not to be mountable!\n");
ret = ask_user("We are going to clear the seeding flag, are you sure?");
if (!ret) {
fprintf(stderr, "Clear seeding flag canceled\n");
return 1;
}
}
ret = update_seeding_flag(root, seeding_value);
if (!ret)
success++;
total++;
}
if (extrefs_flag) {
enable_extrefs_flag(root);
success++;
total++;
}
if (skinny_flag) {
enable_skinny_metadata(root);
success++;
total++;
}
if (success == total) {
ret = 0;
} else {
root->fs_info->readonly = 1;
ret = 1;
fprintf(stderr, "btrfstune failed\n");
}
close_ctree(root);
return ret;
}