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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 <uuid/uuid.h>
#include <getopt.h>
#include "kerncompat.h"
#include "kernel-shared/ctree.h"
#include "kernel-shared/disk-io.h"
#include "kernel-shared/transaction.h"
#include "common/utils.h"
#include "kernel-shared/volumes.h"
#include "common/open-utils.h"
#include "common/help.h"
#include "common/box.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;
int ret;
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
warning("seeding flag is already set on %s",
device);
return 1;
}
super_flags |= BTRFS_SUPER_FLAG_SEEDING;
} else {
if (!(super_flags & BTRFS_SUPER_FLAG_SEEDING)) {
warning("seeding flag is not set on %s", device);
return 1;
}
super_flags &= ~BTRFS_SUPER_FLAG_SEEDING;
warning("seeding flag cleared on %s", device);
}
trans = btrfs_start_transaction(root, 1);
BUG_ON(IS_ERR(trans));
btrfs_set_super_flags(disk_super, super_flags);
ret = btrfs_commit_transaction(trans, root);
return ret;
}
/*
* Return 0 for no unfinished fsid change.
* Return >0 for unfinished fsid change, and restore unfinished fsid/
* chunk_tree_id into fsid_ret/chunk_id_ret.
*/
static int check_unfinished_fsid_change(struct btrfs_fs_info *fs_info,
uuid_t fsid_ret, uuid_t chunk_id_ret)
{
struct btrfs_root *tree_root = fs_info->tree_root;
u64 flags = btrfs_super_flags(fs_info->super_copy);
if (flags & (BTRFS_SUPER_FLAG_CHANGING_FSID |
BTRFS_SUPER_FLAG_CHANGING_FSID_V2)) {
memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
read_extent_buffer(tree_root->node, chunk_id_ret,
btrfs_header_chunk_tree_uuid(tree_root->node),
BTRFS_UUID_SIZE);
return 1;
}
return 0;
}
static int set_metadata_uuid(struct btrfs_root *root, const char *uuid_string)
{
struct btrfs_super_block *disk_super;
uuid_t new_fsid, unused1, unused2;
struct btrfs_trans_handle *trans;
bool new_uuid = true;
u64 incompat_flags;
bool uuid_changed;
u64 super_flags;
int ret;
disk_super = root->fs_info->super_copy;
super_flags = btrfs_super_flags(disk_super);
incompat_flags = btrfs_super_incompat_flags(disk_super);
uuid_changed = incompat_flags & BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
fprintf(stderr, "cannot set metadata UUID on a seed device\n");
return 1;
}
if (check_unfinished_fsid_change(root->fs_info, unused1, unused2)) {
fprintf(stderr,
"UUID rewrite in progress, cannot change fsid\n");
return 1;
}
if (uuid_string)
uuid_parse(uuid_string, new_fsid);
else
uuid_generate(new_fsid);
new_uuid = (memcmp(new_fsid, disk_super->fsid, BTRFS_FSID_SIZE) != 0);
/* Step 1 sets the in progress flag */
trans = btrfs_start_transaction(root, 1);
super_flags |= BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
btrfs_set_super_flags(disk_super, super_flags);
ret = btrfs_commit_transaction(trans, root);
if (ret < 0)
return ret;
if (new_uuid && uuid_changed && memcmp(disk_super->metadata_uuid,
new_fsid, BTRFS_FSID_SIZE) == 0) {
/*
* Changing fsid to be the same as metadata uuid, so just
* disable the flag
*/
memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
incompat_flags &= ~BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
btrfs_set_super_incompat_flags(disk_super, incompat_flags);
memset(disk_super->metadata_uuid, 0, BTRFS_FSID_SIZE);
} else if (new_uuid && uuid_changed && memcmp(disk_super->metadata_uuid,
new_fsid, BTRFS_FSID_SIZE)) {
/*
* Changing fsid on an already changed FS, in this case we
* only change the fsid and don't touch metadata uuid as it
* has already the correct value
*/
memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
} else if (new_uuid && !uuid_changed) {
/*
* First time changing the fsid, copy the fsid to metadata_uuid
*/
incompat_flags |= BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
btrfs_set_super_incompat_flags(disk_super, incompat_flags);
memcpy(disk_super->metadata_uuid, disk_super->fsid,
BTRFS_FSID_SIZE);
memcpy(disk_super->fsid, &new_fsid, BTRFS_FSID_SIZE);
} else {
/* Setting the same fsid as current, do nothing */
return 0;
}
trans = btrfs_start_transaction(root, 1);
/*
* Step 2 is to write the metadata_uuid, set the incompat flag and
* clear the in progress flag
*/
super_flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
btrfs_set_super_flags(disk_super, super_flags);
/* Then actually copy the metadata uuid and set the incompat bit */
return btrfs_commit_transaction(trans, root);
}
static int set_super_incompat_flags(struct btrfs_root *root, u64 flags)
{
struct btrfs_trans_handle *trans;
struct btrfs_super_block *disk_super;
u64 super_flags;
int ret;
disk_super = root->fs_info->super_copy;
super_flags = btrfs_super_incompat_flags(disk_super);
super_flags |= flags;
trans = btrfs_start_transaction(root, 1);
BUG_ON(IS_ERR(trans));
btrfs_set_super_incompat_flags(disk_super, super_flags);
ret = btrfs_commit_transaction(trans, root);
return ret;
}
static int change_buffer_header_uuid(struct extent_buffer *eb, uuid_t new_fsid)
{
struct btrfs_fs_info *fs_info = eb->fs_info;
int same_fsid = 1;
int same_chunk_tree_uuid = 1;
int ret;
same_fsid = !memcmp_extent_buffer(eb, new_fsid, btrfs_header_fsid(),
BTRFS_FSID_SIZE);
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, 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, fs_info, eb);
return ret;
}
static int change_extents_uuid(struct btrfs_fs_info *fs_info, uuid_t new_fsid)
{
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_path path;
struct btrfs_key key = {0, 0, 0};
int ret = 0;
btrfs_init_path(&path);
/*
* Here we don't use transaction as it will takes a lot of reserve
* space, and that will make a near-full btrfs unable to change uuid
*/
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0)
goto out;
while (1) {
struct btrfs_extent_item *ei;
struct extent_buffer *eb;
u64 flags;
u64 bytenr;
btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
if (key.type != BTRFS_EXTENT_ITEM_KEY &&
key.type != BTRFS_METADATA_ITEM_KEY)
goto next;
ei = btrfs_item_ptr(path.nodes[0], path.slots[0],
struct btrfs_extent_item);
flags = btrfs_extent_flags(path.nodes[0], ei);
if (!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
goto next;
bytenr = key.objectid;
eb = read_tree_block(fs_info, bytenr, 0);
if (IS_ERR(eb)) {
error("failed to read tree block: %llu", bytenr);
ret = PTR_ERR(eb);
goto out;
}
ret = change_buffer_header_uuid(eb, new_fsid);
free_extent_buffer(eb);
if (ret < 0) {
error("failed to change uuid of tree block: %llu",
bytenr);
goto out;
}
next:
ret = btrfs_next_item(root, &path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
goto out;
}
}
out:
btrfs_release_path(&path);
return ret;
}
static int change_device_uuid(struct extent_buffer *eb, int slot,
uuid_t new_fsid)
{
struct btrfs_dev_item *di;
struct btrfs_fs_info *fs_info = eb->fs_info;
int ret = 0;
di = btrfs_item_ptr(eb, slot, struct btrfs_dev_item);
if (!memcmp_extent_buffer(eb, new_fsid,
(unsigned long)btrfs_device_fsid(di),
BTRFS_FSID_SIZE))
return ret;
write_extent_buffer(eb, new_fsid, (unsigned long)btrfs_device_fsid(di),
BTRFS_FSID_SIZE);
ret = write_tree_block(NULL, fs_info, eb);
return ret;
}
static int change_devices_uuid(struct btrfs_root *root, uuid_t new_fsid)
{
struct btrfs_path path;
struct btrfs_key key = {0, 0, 0};
int ret = 0;
btrfs_init_path(&path);
/* No transaction again */
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0)
goto out;
while (1) {
btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
if (key.type != BTRFS_DEV_ITEM_KEY ||
key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
goto next;
ret = change_device_uuid(path.nodes[0], path.slots[0],
new_fsid);
if (ret < 0)
goto out;
next:
ret = btrfs_next_item(root, &path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
goto out;
}
}
out:
btrfs_release_path(&path);
return ret;
}
static int change_fsid_prepare(struct btrfs_fs_info *fs_info, uuid_t new_fsid)
{
struct btrfs_root *tree_root = fs_info->tree_root;
u64 flags = btrfs_super_flags(fs_info->super_copy);
int ret = 0;
flags |= BTRFS_SUPER_FLAG_CHANGING_FSID;
btrfs_set_super_flags(fs_info->super_copy, flags);
memcpy(fs_info->super_copy->fsid, new_fsid, BTRFS_FSID_SIZE);
ret = write_all_supers(fs_info);
if (ret < 0)
return ret;
/* Also need to change the metadatauuid of the fs info */
memcpy(fs_info->fs_devices->metadata_uuid, new_fsid, BTRFS_FSID_SIZE);
/* also restore new chunk_tree_id into tree_root for restore */
write_extent_buffer(tree_root->node, fs_info->new_chunk_tree_uuid,
btrfs_header_chunk_tree_uuid(tree_root->node),
BTRFS_UUID_SIZE);
return write_tree_block(NULL, fs_info, tree_root->node);
}
static int change_fsid_done(struct btrfs_fs_info *fs_info)
{
u64 flags = btrfs_super_flags(fs_info->super_copy);
flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID;
btrfs_set_super_flags(fs_info->super_copy, flags);
return write_all_supers(fs_info);
}
/*
* Change fsid of a given fs.
*
* If new_fsid_str is not given, use a random generated UUID.
* Caller should check new_fsid_str is valid
*/
static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str)
{
uuid_t new_fsid;
uuid_t new_chunk_id;
uuid_t old_fsid;
char uuid_buf[BTRFS_UUID_UNPARSED_SIZE];
int ret = 0;
if (check_unfinished_fsid_change(fs_info, new_fsid, new_chunk_id)) {
if (new_fsid_str) {
uuid_t tmp;
uuid_parse(new_fsid_str, tmp);
if (memcmp(tmp, new_fsid, BTRFS_FSID_SIZE)) {
error(
"new fsid %s is not the same with unfinished fsid change",
new_fsid_str);
return -EINVAL;
}
}
} else {
if (new_fsid_str)
uuid_parse(new_fsid_str, new_fsid);
else
uuid_generate(new_fsid);
uuid_generate(new_chunk_id);
}
fs_info->new_chunk_tree_uuid = new_chunk_id;
memcpy(old_fsid, (const char*)fs_info->fs_devices->fsid, BTRFS_UUID_SIZE);
uuid_unparse(old_fsid, uuid_buf);
printf("Current fsid: %s\n", uuid_buf);
uuid_unparse(new_fsid, uuid_buf);
printf("New fsid: %s\n", uuid_buf);
/* Now we can begin fsid change */
printf("Set superblock flag CHANGING_FSID\n");
ret = change_fsid_prepare(fs_info, new_fsid);
if (ret < 0)
goto out;
/* Change extents first */
printf("Change fsid in extents\n");
ret = change_extents_uuid(fs_info, new_fsid);
if (ret < 0) {
error("failed to change UUID of metadata: %d", ret);
goto out;
}
/* Then devices */
printf("Change fsid on devices\n");
ret = change_devices_uuid(fs_info->chunk_root, new_fsid);
if (ret < 0) {
error("failed to change UUID of devices: %d", ret);
goto out;
}
/* Last, change fsid in super */
memcpy(fs_info->fs_devices->fsid, new_fsid, BTRFS_FSID_SIZE);
memcpy(fs_info->super_copy->fsid, new_fsid, BTRFS_FSID_SIZE);
ret = write_all_supers(fs_info);
if (ret < 0)
goto out;
/* Now fsid change is done */
printf("Clear superblock flag CHANGING_FSID\n");
ret = change_fsid_done(fs_info);
fs_info->new_chunk_tree_uuid = NULL;
printf("Fsid change finished\n");
out:
return ret;
}
static void print_usage(void)
{
printf("usage: btrfstune [options] device\n");
printf("Tune settings of filesystem features on an unmounted device\n\n");
printf("Options:\n");
printf(" change feature status:\n");
printf("\t-r enable extended inode refs (mkfs: extref, for hardlink limits)\n");
printf("\t-x enable skinny metadata extent refs (mkfs: skinny-metadata)\n");
printf("\t-n enable no-holes feature (mkfs: no-holes, more efficient sparse file representation)\n");
printf("\t-S <0|1> set/unset seeding status of a device\n");
printf(" uuid changes:\n");
printf("\t-u rewrite fsid, use a random one\n");
printf("\t-U UUID rewrite fsid to UUID\n");
printf("\t-m change fsid in metadata_uuid to a random UUID\n");
printf("\t (incompat change, more lightweight than -u|-U)\n");
printf("\t-M UUID change fsid in metadata_uuid to UUID\n");
printf(" general:\n");
printf("\t-f allow dangerous operations, make sure that you are aware of the dangers\n");
printf("\t--help print this help\n");
}
int BOX_MAIN(btrfstune)(int argc, char *argv[])
{
struct btrfs_root *root;
unsigned ctree_flags = OPEN_CTREE_WRITES;
int success = 0;
int total = 0;
int seeding_flag = 0;
u64 seeding_value = 0;
int random_fsid = 0;
int change_metadata_uuid = 0;
char *new_fsid_str = NULL;
int ret;
u64 super_flags = 0;
int fd = -1;
while(1) {
static const struct option long_options[] = {
{ "help", no_argument, NULL, GETOPT_VAL_HELP},
{ NULL, 0, NULL, 0 }
};
int c = getopt_long(argc, argv, "S:rxfuU:nmM:", long_options, NULL);
if (c < 0)
break;
switch(c) {
case 'S':
seeding_flag = 1;
seeding_value = arg_strtou64(optarg);
break;
case 'r':
super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
break;
case 'x':
super_flags |= BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA;
break;
case 'n':
super_flags |= BTRFS_FEATURE_INCOMPAT_NO_HOLES;
break;
case 'f':
force = 1;
break;
case 'U':
ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
new_fsid_str = optarg;
break;
case 'u':
ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
random_fsid = 1;
break;
case 'M':
ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
change_metadata_uuid = 1;
new_fsid_str = optarg;
break;
case 'm':
ctree_flags |= OPEN_CTREE_IGNORE_FSID_MISMATCH;
change_metadata_uuid = 1;
break;
case GETOPT_VAL_HELP:
default:
print_usage();
return c != GETOPT_VAL_HELP;
}
}
set_argv0(argv);
device = argv[optind];
if (check_argc_exact(argc - optind, 1))
return 1;
if (random_fsid && new_fsid_str) {
error("random fsid can't be used with specified fsid");
return 1;
}
if (!super_flags && !seeding_flag && !(random_fsid || new_fsid_str) &&
!change_metadata_uuid) {
error("at least one option should be specified");
print_usage();
return 1;
}
if (new_fsid_str) {
uuid_t tmp;
ret = uuid_parse(new_fsid_str, tmp);
if (ret < 0) {
error("could not parse UUID: %s", new_fsid_str);
return 1;
}
if (!test_uuid_unique(new_fsid_str)) {
error("fsid %s is not unique", new_fsid_str);
return 1;
}
}
fd = open(device, O_RDWR);
if (fd < 0) {
error("mount check: cannot open %s: %m", device);
return 1;
}
ret = check_mounted_where(fd, device, NULL, 0, NULL,
SBREAD_IGNORE_FSID_MISMATCH);
if (ret < 0) {
errno = -ret;
error("could not check mount status of %s: %m", device);
close(fd);
return 1;
} else if (ret) {
error("%s is mounted", device);
close(fd);
return 1;
}
root = open_ctree_fd(fd, device, 0, ctree_flags);
if (!root) {
error("open ctree failed");
return 1;
}
if (seeding_flag) {
if (btrfs_fs_incompat(root->fs_info, METADATA_UUID)) {
fprintf(stderr, "SEED flag cannot be changed on a metadata-uuid changed fs\n");
ret = 1;
goto out;
}
if (!seeding_value && !force) {
warning(
"this is dangerous, clearing the seeding flag may cause the derived device not to be mountable!");
ret = ask_user("We are going to clear the seeding flag, are you sure?");
if (!ret) {
fprintf(stderr, "Clear seeding flag canceled\n");
ret = 1;
goto out;
}
}
ret = update_seeding_flag(root, seeding_value);
if (!ret)
success++;
total++;
}
if (super_flags) {
ret = set_super_incompat_flags(root, super_flags);
if (!ret)
success++;
total++;
}
if (change_metadata_uuid) {
if (seeding_flag) {
fprintf(stderr,
"Not allowed to set both seeding flag and uuid metadata\n");
ret = 1;
goto out;
}
if (new_fsid_str)
ret = set_metadata_uuid(root, new_fsid_str);
else
ret = set_metadata_uuid(root, NULL);
if (!ret)
success++;
total++;
}
if (random_fsid || (new_fsid_str && !change_metadata_uuid)) {
if (btrfs_fs_incompat(root->fs_info, METADATA_UUID)) {
fprintf(stderr,
"Cannot rewrite fsid while METADATA_UUID flag is active. \n"
"Ensure fsid and metadata_uuid match before retrying.\n");
ret = 1;
goto out;
}
if (!force) {
warning(
"it's recommended to run 'btrfs check --readonly' before this operation.\n"
"\tThe whole operation must finish before the filesystem can be mounted again.\n"
"\tIf cancelled or interrupted, run 'btrfstune -u' to restart.");
ret = ask_user("We are going to change UUID, are your sure?");
if (!ret) {
fprintf(stderr, "UUID change canceled\n");
ret = 1;
goto out;
}
}
ret = change_uuid(root->fs_info, new_fsid_str);
if (!ret)
success++;
total++;
}
if (success == total) {
ret = 0;
} else {
root->fs_info->readonly = 1;
ret = 1;
error("btrfstune failed");
}
out:
close_ctree(root);
btrfs_close_all_devices();
return ret;
}
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