@@ -2318,7 +2318,7 @@ int btrfs_init_cachep(void);
void btrfs_destroy_cachep(void);
long btrfs_ioctl_trans_end(struct file *file);
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
- struct btrfs_root *root);
+ struct btrfs_root *root, int *was_new);
int btrfs_commit_write(struct file *file, struct page *page,
unsigned from, unsigned to);
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
@@ -95,7 +95,7 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
- inode = btrfs_iget(sb, &key, root);
+ inode = btrfs_iget(sb, &key, root, NULL);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto fail;
@@ -223,7 +223,7 @@ static struct dentry *btrfs_get_parent(struct dentry *child)
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
- dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root));
+ dentry = d_obtain_alias(btrfs_iget(root->fs_info->sb, &key, root, NULL));
if (!IS_ERR(dentry))
dentry->d_op = &btrfs_dentry_operations;
return dentry;
@@ -2131,7 +2131,7 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
found_key.objectid = found_key.offset;
found_key.type = BTRFS_INODE_ITEM_KEY;
found_key.offset = 0;
- inode = btrfs_iget(root->fs_info->sb, &found_key, root);
+ inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
if (IS_ERR(inode))
break;
@@ -3609,7 +3609,7 @@ static struct inode *btrfs_iget_locked(struct super_block *s,
* Returns in *is_new if the inode was read from disk
*/
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
- struct btrfs_root *root)
+ struct btrfs_root *root, int *new)
{
struct inode *inode;
@@ -3624,6 +3624,8 @@ struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
inode_tree_add(inode);
unlock_new_inode(inode);
+ if (new)
+ *new = 1;
}
return inode;
@@ -3676,7 +3678,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
return NULL;
if (location.type == BTRFS_INODE_ITEM_KEY) {
- inode = btrfs_iget(dir->i_sb, &location, root);
+ inode = btrfs_iget(dir->i_sb, &location, root, NULL);
return inode;
}
@@ -3691,7 +3693,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
else
inode = new_simple_dir(dir->i_sb, &location, sub_root);
} else {
- inode = btrfs_iget(dir->i_sb, &location, sub_root);
+ inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
}
srcu_read_unlock(&root->fs_info->subvol_srcu, index);
@@ -3478,7 +3478,7 @@ static struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
key.objectid = objectid;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
- inode = btrfs_iget(root->fs_info->sb, &key, root);
+ inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
BTRFS_I(inode)->index_cnt = group->key.objectid;
@@ -72,7 +72,7 @@ enum {
static match_table_t tokens = {
{Opt_degraded, "degraded"},
- {Opt_subvol, "subvol=%s"},
+ {Opt_subvol, "subvol=%d"},
{Opt_device, "device=%s"},
{Opt_nodatasum, "nodatasum"},
{Opt_nodatacow, "nodatacow"},
@@ -277,12 +277,13 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
* only when we need to allocate a new super block.
*/
static int btrfs_parse_early_options(const char *options, fmode_t flags,
- void *holder, char **subvol_name,
+ void *holder, u64 *subvol_objectid,
struct btrfs_fs_devices **fs_devices)
{
substring_t args[MAX_OPT_ARGS];
char *opts, *p;
int error = 0;
+ int intarg;
if (!options)
goto out;
@@ -303,7 +304,10 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
token = match_token(p, tokens, args);
switch (token) {
case Opt_subvol:
- *subvol_name = match_strdup(&args[0]);
+ intarg = 0;
+ match_int(&args[0], &intarg);
+ if (intarg)
+ *subvol_objectid = intarg;
break;
case Opt_device:
error = btrfs_scan_one_device(match_strdup(&args[0]),
@@ -319,17 +323,110 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
out_free_opts:
kfree(opts);
out:
+ return error;
+}
+
+static struct dentry *get_default_root(struct super_block *sb, u64 subvol_objectid)
+{
+ struct btrfs_root *root = sb->s_fs_info;
+ struct btrfs_root *new_root;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ struct btrfs_key location;
+ struct inode *inode;
+ struct dentry *dentry;
+ u64 dir_id;
+ int new = 0;
+
/*
- * If no subvolume name is specified we use the default one. Allocate
- * a copy of the string "." here so that code later in the
- * mount path doesn't care if it's the default volume or another one.
+ * We have a specific subvol we want to mount, just setup location and
+ * go look up the root.
*/
- if (!*subvol_name) {
- *subvol_name = kstrdup(".", GFP_KERNEL);
- if (!*subvol_name)
- return -ENOMEM;
+ if (subvol_objectid) {
+ location.objectid = subvol_objectid;
+ location.type = BTRFS_ROOT_ITEM_KEY;
+ location.offset = (u64)-1;
+ goto find_root;
}
- return error;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return ERR_PTR(-ENOMEM);
+ path->leave_spinning = 1;
+
+ /*
+ * Find the "default" dir item which points to the root item that we
+ * will mount by default if we haven't been given a specific subvolume
+ * to mount.
+ */
+ dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
+ di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
+ if (!di) {
+ /*
+ * Ok the default dir item isn't there. This is weird since
+ * it's always been there, but don't freak out, just try and
+ * mount to root most subvolume.
+ */
+ btrfs_free_path(path);
+ dir_id = BTRFS_FIRST_FREE_OBJECTID;
+ new_root = root->fs_info->fs_root;
+ goto setup_root;
+ }
+
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+ btrfs_free_path(path);
+
+find_root:
+ new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
+ if (IS_ERR(new_root))
+ return ERR_PTR(PTR_ERR(new_root));
+
+ if (btrfs_root_refs(&new_root->root_item) == 0)
+ return ERR_PTR(-ENOENT);
+
+ dir_id = btrfs_root_dirid(&new_root->root_item);
+setup_root:
+ location.objectid = dir_id;
+ location.type = BTRFS_INODE_ITEM_KEY;
+ location.offset = 0;
+
+ inode = btrfs_iget(sb, &location, new_root, &new);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * If we're just mounting the root most subvol put the inode and return
+ * a reference to the dentry. We will have already gotten a reference
+ * to the inode in btrfs_fill_super so we're good to go.
+ */
+ if (!new && sb->s_root->d_inode == inode) {
+ iput(inode);
+ return dget(sb->s_root);
+ }
+
+ if (new) {
+ const struct qstr name = { .name = "/", .len = 1 };
+
+ /*
+ * New inode, we need to make the dentry a sibling of s_root so
+ * everything gets cleaned up properly on unmount.
+ */
+ dentry = d_alloc(sb->s_root, &name);
+ if (!dentry) {
+ iput(inode);
+ return ERR_PTR(-ENOMEM);
+ }
+ d_splice_alias(inode, dentry);
+ } else {
+ /*
+ * We found the inode in cache, just find a dentry for it and
+ * put the reference to the inode we just got.
+ */
+ dentry = d_find_alias(inode);
+ iput(inode);
+ }
+
+ return dentry;
}
static int btrfs_fill_super(struct super_block *sb,
@@ -365,7 +462,7 @@ static int btrfs_fill_super(struct super_block *sb,
key.objectid = BTRFS_FIRST_FREE_OBJECTID;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
- inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root);
+ inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto fail_close;
@@ -377,12 +474,6 @@ static int btrfs_fill_super(struct super_block *sb,
err = -ENOMEM;
goto fail_close;
}
-#if 0
- /* this does the super kobj at the same time */
- err = btrfs_sysfs_add_super(tree_root->fs_info);
- if (err)
- goto fail_close;
-#endif
sb->s_root = root_dentry;
@@ -472,29 +563,30 @@ static int btrfs_test_super(struct super_block *s, void *data)
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;
+ u64 subvol_objectid = 0;
int error = 0;
+ int found = 0;
if (!(flags & MS_RDONLY))
mode |= FMODE_WRITE;
error = btrfs_parse_early_options(data, mode, fs_type,
- &subvol_name, &fs_devices);
+ &subvol_objectid, &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;
+ goto error;
error = btrfs_open_devices(fs_devices, mode, fs_type);
if (error)
- goto error_free_subvol_name;
+ goto error;
if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
error = -EACCES;
@@ -513,6 +605,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
goto error_close_devices;
}
+ found = 1;
btrfs_close_devices(fs_devices);
} else {
char b[BDEVNAME_SIZE];
@@ -523,46 +616,30 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
flags & MS_SILENT ? 1 : 0);
if (error) {
deactivate_locked_super(s);
- goto error_free_subvol_name;
+ goto error;
}
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)) {
- deactivate_locked_super(s);
- error = PTR_ERR(root);
- goto error_free_subvol_name;
- }
- if (!root->d_inode) {
- dput(root);
- deactivate_locked_super(s);
- error = -ENXIO;
- goto error_free_subvol_name;
- }
+ root = get_default_root(s, subvol_objectid);
+ if (IS_ERR(root)) {
+ error = PTR_ERR(root);
+ deactivate_locked_super(s);
+ goto error;
}
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);
+error:
return error;
}
@@ -445,7 +445,7 @@ static noinline struct inode *read_one_inode(struct btrfs_root *root,
key.objectid = objectid;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
- inode = btrfs_iget(root->fs_info->sb, &key, root);
+ inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
if (IS_ERR(inode)) {
inode = NULL;
} else if (is_bad_inode(inode)) {