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;
}
static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
u64 sb_bytenr,
u64 root_tree_bytenr, int writes,
int partial)
{
u32 sectorsize;
u32 nodesize;
u32 leafsize;
u32 blocksize;
u32 stripesize;
u64 generation;
struct btrfs_key key;
struct btrfs_root *tree_root = malloc(sizeof(struct btrfs_root));
struct btrfs_root *extent_root = malloc(sizeof(struct btrfs_root));
struct btrfs_root *chunk_root = malloc(sizeof(struct btrfs_root));
struct btrfs_root *dev_root = malloc(sizeof(struct btrfs_root));
struct btrfs_root *csum_root = malloc(sizeof(struct btrfs_root));
struct btrfs_fs_info *fs_info = malloc(sizeof(*fs_info));
int ret;
struct btrfs_super_block *disk_super;
struct btrfs_fs_devices *fs_devices = NULL;
u64 total_devs;
u64 features;
if (sb_bytenr == 0)
sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
/* try to drop all the caches */
if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
fprintf(stderr, "Warning, could not drop caches\n");
ret = btrfs_scan_one_device(fp, path, &fs_devices,
&total_devs, sb_bytenr);
if (ret) {
fprintf(stderr, "No valid Btrfs found on %s\n", path);
goto out;
}
if (total_devs != 1) {
ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1);
if (ret)
goto out;
}
memset(fs_info, 0, sizeof(*fs_info));
fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
fs_info->tree_root = tree_root;
fs_info->extent_root = extent_root;
fs_info->chunk_root = chunk_root;
fs_info->dev_root = dev_root;
fs_info->csum_root = csum_root;
if (!writes)
fs_info->readonly = 1;
extent_io_tree_init(&fs_info->extent_cache);
extent_io_tree_init(&fs_info->free_space_cache);
extent_io_tree_init(&fs_info->block_group_cache);
extent_io_tree_init(&fs_info->pinned_extents);
extent_io_tree_init(&fs_info->pending_del);
extent_io_tree_init(&fs_info->extent_ins);
cache_tree_init(&fs_info->fs_root_cache);
cache_tree_init(&fs_info->mapping_tree.cache_tree);
mutex_init(&fs_info->fs_mutex);
fs_info->fs_devices = fs_devices;
INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
INIT_LIST_HEAD(&fs_info->space_info);
__setup_root(4096, 4096, 4096, 4096, tree_root,
fs_info, BTRFS_ROOT_TREE_OBJECTID);
if (writes)
ret = btrfs_open_devices(fs_devices, O_RDWR);
else
ret = btrfs_open_devices(fs_devices, O_RDONLY);
if (ret)
goto out_cleanup;
fs_info->super_bytenr = sb_bytenr;
disk_super = fs_info->super_copy;
ret = btrfs_read_dev_super(fs_devices->latest_bdev,
disk_super, sb_bytenr);
if (ret) {
printk("No valid btrfs found\n");
goto out_devices;
}
memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
features = btrfs_super_incompat_flags(disk_super) &
~BTRFS_FEATURE_INCOMPAT_SUPP;
if (features) {
printk("couldn't open because of unsupported "
"option features (%Lx).\n",
(unsigned long long)features);
goto out_devices;
}
features = btrfs_super_incompat_flags(disk_super);
if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
btrfs_set_super_incompat_flags(disk_super, features);
}
features = btrfs_super_compat_ro_flags(disk_super) &
~BTRFS_FEATURE_COMPAT_RO_SUPP;
if (writes && features) {
printk("couldn't open RDWR because of unsupported "
"option features (%Lx).\n",
(unsigned long long)features);
goto out_devices;
}
nodesize = btrfs_super_nodesize(disk_super);
leafsize = btrfs_super_leafsize(disk_super);
sectorsize = btrfs_super_sectorsize(disk_super);
stripesize = btrfs_super_stripesize(disk_super);
tree_root->nodesize = nodesize;
tree_root->leafsize = leafsize;
tree_root->sectorsize = sectorsize;
tree_root->stripesize = stripesize;
ret = btrfs_read_sys_array(tree_root);
if (ret)
goto out_devices;
blocksize = btrfs_level_size(tree_root,
btrfs_super_chunk_root_level(disk_super));
generation = btrfs_super_chunk_root_generation(disk_super);
__setup_root(nodesize, leafsize, sectorsize, stripesize,
chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
chunk_root->node = read_tree_block(chunk_root,
btrfs_super_chunk_root(disk_super),
blocksize, generation);
if (!extent_buffer_uptodate(chunk_root->node)) {
printk("Couldn't read chunk root\n");
goto out_devices;
}
read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
(unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
BTRFS_UUID_SIZE);
if (!(btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)) {
ret = btrfs_read_chunk_tree(chunk_root);
if (ret) {
printk("Couldn't read chunk tree\n");
goto out_chunk;
}
}
blocksize = btrfs_level_size(tree_root,
btrfs_super_root_level(disk_super));
generation = btrfs_super_generation(disk_super);
if (!root_tree_bytenr)
root_tree_bytenr = btrfs_super_root(disk_super);
tree_root->node = read_tree_block(tree_root,
root_tree_bytenr,
blocksize, generation);
if (!extent_buffer_uptodate(tree_root->node)) {
printk("Couldn't read tree root\n");
goto out_failed;
}
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_EXTENT_TREE_OBJECTID, extent_root);
if (ret) {
printk("Couldn't setup extent tree\n");
goto out_failed;
}
extent_root->track_dirty = 1;
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_DEV_TREE_OBJECTID, dev_root);
if (ret) {
printk("Couldn't setup device tree\n");
goto out_failed;
}
dev_root->track_dirty = 1;
ret = find_and_setup_root(tree_root, fs_info,
BTRFS_CSUM_TREE_OBJECTID, csum_root);
if (ret) {
printk("Couldn't setup csum tree\n");
if (!partial)
goto out_failed;
}
csum_root->track_dirty = 1;
find_and_setup_log_root(tree_root, fs_info, disk_super);
fs_info->generation = generation;
fs_info->last_trans_committed = generation;
btrfs_read_block_groups(fs_info->tree_root);
key.objectid = BTRFS_FS_TREE_OBJECTID;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);
if (!fs_info->fs_root)
goto out_failed;
fs_info->data_alloc_profile = (u64)-1;
fs_info->metadata_alloc_profile = (u64)-1;
fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
return fs_info;
out_failed:
if (partial)
return fs_info;
if (fs_info->csum_root)
free_extent_buffer(fs_info->csum_root->node);
if (fs_info->dev_root)
free_extent_buffer(fs_info->dev_root->node);
if (fs_info->extent_root)
free_extent_buffer(fs_info->extent_root->node);
if (fs_info->tree_root)
free_extent_buffer(fs_info->tree_root->node);
out_chunk:
if (fs_info->chunk_root)
free_extent_buffer(fs_info->chunk_root->node);
out_devices:
close_all_devices(fs_info);
out_cleanup:
extent_io_tree_cleanup(&fs_info->extent_cache);
extent_io_tree_cleanup(&fs_info->free_space_cache);
extent_io_tree_cleanup(&fs_info->block_group_cache);
extent_io_tree_cleanup(&fs_info->pinned_extents);
extent_io_tree_cleanup(&fs_info->pending_del);
extent_io_tree_cleanup(&fs_info->extent_ins);
out:
free(tree_root);
free(extent_root);
free(chunk_root);
free(dev_root);
free(csum_root);
free(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;
}
