static struct btrfs_root *open_ctree_broken(int fd, const char *device) { struct btrfs_fs_info *fs_info; struct btrfs_super_block *disk_super; struct btrfs_fs_devices *fs_devices = NULL; struct extent_buffer *eb; int ret; fs_info = btrfs_new_fs_info(0, BTRFS_SUPER_INFO_OFFSET); if (!fs_info) { fprintf(stderr, "Failed to allocate memory for fs_info\n"); return NULL; } ret = btrfs_scan_fs_devices(fd, device, &fs_devices, 0, 1); if (ret) goto out; fs_info->fs_devices = fs_devices; ret = btrfs_open_devices(fs_devices, O_RDONLY); if (ret) goto out_devices; disk_super = fs_info->super_copy; ret = btrfs_read_dev_super(fs_devices->latest_bdev, disk_super, fs_info->super_bytenr, 1); if (ret) { printk("No valid btrfs found\n"); goto out_devices; } memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE); ret = btrfs_check_fs_compatibility(disk_super, 0); if (ret) goto out_devices; ret = btrfs_setup_chunk_tree_and_device_map(fs_info); if (ret) goto out_chunk; eb = fs_info->chunk_root->node; read_extent_buffer(eb, fs_info->chunk_tree_uuid, btrfs_header_chunk_tree_uuid(eb), BTRFS_UUID_SIZE); return fs_info->chunk_root; out_chunk: free_extent_buffer(fs_info->chunk_root->node); btrfs_cleanup_all_caches(fs_info); out_devices: btrfs_close_devices(fs_info->fs_devices); out: btrfs_free_fs_info(fs_info); return NULL; }
/* * Find a superblock for the given device / mount point. * * Note: This is based on get_sb_bdev from fs/super.c with a few additions * for multiple device setup. Make sure to keep it in sync. */ static int btrfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { char *subvol_name = NULL; struct block_device *bdev = NULL; struct super_block *s; struct dentry *root; struct btrfs_fs_devices *fs_devices = NULL; fmode_t mode = FMODE_READ; int error = 0; if (!(flags & MS_RDONLY)) mode |= FMODE_WRITE; error = btrfs_parse_early_options(data, mode, fs_type, &subvol_name, &fs_devices); if (error) return error; error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); if (error) goto error_free_subvol_name; error = btrfs_open_devices(fs_devices, mode, fs_type); if (error) goto error_free_subvol_name; if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { error = -EACCES; goto error_close_devices; } bdev = fs_devices->latest_bdev; s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); if (IS_ERR(s)) goto error_s; if (s->s_root) { if ((flags ^ s->s_flags) & MS_RDONLY) { up_write(&s->s_umount); deactivate_super(s); error = -EBUSY; goto error_close_devices; } btrfs_close_devices(fs_devices); } else { char b[BDEVNAME_SIZE]; s->s_flags = flags; strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); error = btrfs_fill_super(s, fs_devices, data, flags & MS_SILENT ? 1 : 0); if (error) { up_write(&s->s_umount); deactivate_super(s); goto error_free_subvol_name; } btrfs_sb(s)->fs_info->bdev_holder = fs_type; s->s_flags |= MS_ACTIVE; } if (!strcmp(subvol_name, ".")) root = dget(s->s_root); else { mutex_lock(&s->s_root->d_inode->i_mutex); root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name)); mutex_unlock(&s->s_root->d_inode->i_mutex); if (IS_ERR(root)) { up_write(&s->s_umount); deactivate_super(s); error = PTR_ERR(root); goto error_free_subvol_name; } if (!root->d_inode) { dput(root); up_write(&s->s_umount); deactivate_super(s); error = -ENXIO; goto error_free_subvol_name; } } mnt->mnt_sb = s; mnt->mnt_root = root; kfree(subvol_name); return 0; error_s: error = PTR_ERR(s); error_close_devices: btrfs_close_devices(fs_devices); error_free_subvol_name: kfree(subvol_name); return error; }