143 lines
4.4 KiB
C
143 lines
4.4 KiB
C
/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include "kerncompat.h"
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#include <stdbool.h>
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#include <string.h>
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#include <uuid/uuid.h>
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#include "kernel-shared/accessors.h"
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#include "kernel-shared/uapi/btrfs_tree.h"
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#include "kernel-shared/uapi/btrfs.h"
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#include "kernel-shared/ctree.h"
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#include "kernel-shared/transaction.h"
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#include "kernel-shared/volumes.h"
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#include "common/messages.h"
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#include "tune/tune.h"
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/*
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* Return 0 for no unfinished metadata_uuid change.
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* Return >0 for unfinished metadata_uuid change, and restore unfinished
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* fsid/metadata_uuid into fsid_ret/metadata_uuid_ret.
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*/
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static int check_unfinished_metadata_uuid(struct btrfs_fs_info *fs_info,
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uuid_t fsid_ret,
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uuid_t metadata_uuid_ret)
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{
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struct btrfs_root *tree_root = fs_info->tree_root;
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if (fs_info->fs_devices->inconsistent_super) {
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memcpy(fsid_ret, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
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read_extent_buffer(tree_root->node, metadata_uuid_ret,
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btrfs_header_chunk_tree_uuid(tree_root->node),
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BTRFS_UUID_SIZE);
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return 1;
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}
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return 0;
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}
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int set_metadata_uuid(struct btrfs_root *root, const char *new_fsid_string)
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{
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struct btrfs_super_block *disk_super;
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uuid_t fsid, metadata_uuid;
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struct btrfs_trans_handle *trans;
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bool new_fsid = true;
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u64 incompat_flags;
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bool fsid_changed;
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u64 super_flags;
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int ret;
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disk_super = root->fs_info->super_copy;
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super_flags = btrfs_super_flags(disk_super);
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incompat_flags = btrfs_super_incompat_flags(disk_super);
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fsid_changed = incompat_flags & BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
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if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
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error("cannot set metadata UUID on a seed device");
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return 1;
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}
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if (check_unfinished_metadata_uuid(root->fs_info, fsid, metadata_uuid)) {
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if (new_fsid_string) {
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uuid_t tmp;
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uuid_parse(new_fsid_string, tmp);
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if (memcmp(tmp, fsid, BTRFS_FSID_SIZE) != 0) {
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error(
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"new fsid %s is not the same with unfinished fsid change",
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new_fsid_string);
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return -EINVAL;
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}
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}
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} else {
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if (new_fsid_string)
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uuid_parse(new_fsid_string, fsid);
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else
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uuid_generate(fsid);
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}
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new_fsid = (memcmp(fsid, disk_super->fsid, BTRFS_FSID_SIZE) != 0);
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/* Step 1 sets the in progress flag */
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trans = btrfs_start_transaction(root, 1);
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super_flags |= BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
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btrfs_set_super_flags(disk_super, super_flags);
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ret = btrfs_commit_transaction(trans, root);
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if (ret < 0)
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return ret;
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if (new_fsid && fsid_changed && memcmp(disk_super->metadata_uuid,
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fsid, BTRFS_FSID_SIZE) == 0) {
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/*
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* Changing fsid to be the same as metadata uuid, so just
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* disable the flag
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*/
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memcpy(disk_super->fsid, &fsid, BTRFS_FSID_SIZE);
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incompat_flags &= ~BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
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btrfs_set_super_incompat_flags(disk_super, incompat_flags);
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memset(disk_super->metadata_uuid, 0, BTRFS_FSID_SIZE);
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} else if (new_fsid && fsid_changed && memcmp(disk_super->metadata_uuid,
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fsid, BTRFS_FSID_SIZE)) {
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/*
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* Changing fsid on an already changed FS, in this case we
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* only change the fsid and don't touch metadata uuid as it
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* has already the correct value
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*/
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memcpy(disk_super->fsid, &fsid, BTRFS_FSID_SIZE);
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} else if (new_fsid && !fsid_changed) {
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/*
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* First time changing the fsid, copy the fsid to metadata_uuid
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*/
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incompat_flags |= BTRFS_FEATURE_INCOMPAT_METADATA_UUID;
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btrfs_set_super_incompat_flags(disk_super, incompat_flags);
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memcpy(disk_super->metadata_uuid, disk_super->fsid,
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BTRFS_FSID_SIZE);
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memcpy(disk_super->fsid, &fsid, BTRFS_FSID_SIZE);
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}
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trans = btrfs_start_transaction(root, 1);
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/*
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* Step 2 is to write the metadata_uuid, set the incompat flag and
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* clear the in progress flag
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*/
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super_flags &= ~BTRFS_SUPER_FLAG_CHANGING_FSID_V2;
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btrfs_set_super_flags(disk_super, super_flags);
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/* Then actually copy the metadata uuid and set the incompat bit */
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return btrfs_commit_transaction(trans, root);
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}
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