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 "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "common/utils.h"
#include "volumes.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;
}
btrfs-progs: btrfstune: Add support for changing the metadata uuid This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-11 15:04:00 +00:00
/*
* 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;
btrfs-progs: btrfstune: Add support for changing the metadata uuid This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-11 15:04:00 +00:00
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 }
};
btrfs-progs: btrfstune: Add support for changing the metadata uuid This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-11 15:04:00 +00:00
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;
btrfs-progs: btrfstune: Add support for changing the metadata uuid This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-11 15:04:00 +00:00
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;
}
btrfs-progs: btrfstune: Add support for changing the metadata uuid This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-11 15:04:00 +00:00
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) {
btrfs-progs: btrfstune: Add support for changing the metadata uuid This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-11 15:04:00 +00:00
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++;
}
btrfs-progs: btrfstune: Add support for changing the metadata uuid This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-11 15:04:00 +00:00
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;
}