@@ -2361,10 +2361,10 @@ static int repair_inode_backrefs(struct btrfs_root *root,
struct btrfs_trans_handle *trans;
struct btrfs_key location;
- ret = check_dir_conflict(root, backref->name,
- backref->namelen,
- backref->dir,
- backref->index);
+ ret = btrfs_check_dir_conflict(root, backref->name,
+ backref->namelen,
+ backref->dir,
+ backref->index);
if (ret) {
/*
* let nlink fixing routine to handle it,
@@ -106,3 +106,110 @@ error:
btrfs_abort_transaction(trans, ret);
return ret;
}
+
+/*
+ * Link subvoume @subvol as @name under directory inode @parent_dir of
+ * subvolume @parent_root.
+ */
+int btrfs_link_subvolume(struct btrfs_trans_handle *trans,
+ struct btrfs_root *parent_root,
+ u64 parent_dir, const char *name,
+ int namelen, struct btrfs_root *subvol)
+{
+ struct btrfs_root *tree_root = trans->fs_info->tree_root;
+ struct btrfs_path path = { 0 };
+ struct btrfs_key key;
+ struct btrfs_inode_item *ii;
+ u64 index;
+ u64 isize;
+ u32 imode;
+ int ret;
+
+ UASSERT(namelen && namelen <= BTRFS_NAME_LEN);
+
+ /* Make sure @parent_dir is a directory. */
+ key.objectid = parent_dir;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+ ret = btrfs_search_slot(NULL, parent_root, &key, &path, 0, 0);
+ if (ret > 0)
+ ret = -ENOENT;
+ if (ret < 0) {
+ btrfs_release_path(&path);
+ return ret;
+ }
+ ii = btrfs_item_ptr(path.nodes[0], path.slots[0], struct btrfs_inode_item);
+ imode = btrfs_inode_mode(path.nodes[0], ii);
+ btrfs_release_path(&path);
+
+ if (!S_ISDIR(imode)) {
+ ret = -EUCLEAN;
+ error("%s: inode %llu of subvolume %llu is not a directory",
+ __func__, parent_dir, parent_root->root_key.objectid);
+ return ret;
+ }
+
+ ret = btrfs_find_free_dir_index(parent_root, parent_dir, &index);
+ if (ret < 0)
+ return ret;
+
+ /* Filename conflicts check. */
+ ret = btrfs_check_dir_conflict(parent_root, name, namelen, parent_dir,
+ index);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Now everything is fine, add the link.
+ * From now on, every error would lead to transaction abort.
+ *
+ * Add the dir_item/index first.
+ */
+ ret = btrfs_insert_dir_item(trans, parent_root, name, namelen,
+ parent_dir, &subvol->root_key,
+ BTRFS_FT_DIR, index);
+ if (ret < 0)
+ goto abort;
+
+ /* Update inode size of the parent inode */
+ key.objectid = parent_dir;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+ ret = btrfs_search_slot(trans, parent_root, &key, &path, 1, 1);
+ if (ret > 0)
+ ret = -ENOENT;
+ if (ret < 0) {
+ btrfs_release_path(&path);
+ goto abort;
+ }
+ ii = btrfs_item_ptr(path.nodes[0], path.slots[0],
+ struct btrfs_inode_item);
+ isize = btrfs_inode_size(path.nodes[0], ii);
+ isize += namelen * 2;
+ btrfs_set_inode_size(path.nodes[0], ii, isize);
+ btrfs_mark_buffer_dirty(path.nodes[0]);
+ btrfs_release_path(&path);
+
+ /* Add the root backref. */
+ ret = btrfs_add_root_ref(trans, tree_root, subvol->root_key.objectid,
+ BTRFS_ROOT_BACKREF_KEY,
+ parent_root->root_key.objectid, parent_dir,
+ index, name, namelen);
+ if (ret < 0)
+ goto abort;
+
+ /* Then forward ref*/
+ ret = btrfs_add_root_ref(trans, tree_root,
+ parent_root->root_key.objectid,
+ BTRFS_ROOT_REF_KEY, subvol->root_key.objectid,
+ parent_dir, index, name, namelen);
+ if (ret < 0)
+ goto abort;
+ /* For now, all root should have its refs == 1 already.
+ * So no need to update the root refs. */
+ UASSERT(btrfs_root_refs(&subvol->root_item) == 1);
+ return 0;
+abort:
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+}
@@ -22,5 +22,9 @@
int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid);
int btrfs_make_subvolume(struct btrfs_trans_handle *trans, u64 objectid);
+int btrfs_link_subvolume(struct btrfs_trans_handle *trans,
+ struct btrfs_root *parent_root,
+ u64 parent_dir, const char *name,
+ int namelen, struct btrfs_root *subvol);
#endif
@@ -1110,6 +1110,62 @@ static int convert_open_fs(const char *devname,
return -1;
}
+static int link_image_subvolume(struct btrfs_root *image_root, char *name)
+{
+ struct btrfs_fs_info *fs_info = image_root->fs_info;
+ struct btrfs_root *fs_root = fs_info->fs_root;
+ struct btrfs_trans_handle *trans;
+ char buf[BTRFS_NAME_LEN + 1]; /* for snprintf, null terminated. */
+ int ret;
+
+ /*
+ * 1 root backref 1 root forward ref, 1 dir item 1 dir index,
+ * and finally one root item.
+ */
+ trans = btrfs_start_transaction(fs_root, 5);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ errno = -ret;
+ error("failed to start transaction to link subvolume: %m");
+ return PTR_ERR(trans);
+ }
+ ret = btrfs_link_subvolume(trans, fs_root, btrfs_root_dirid(&fs_root->root_item),
+ name, strlen(name), image_root);
+ /* No filename conflicts, all done. */
+ if (!ret)
+ goto commit;
+ /* Other unexpected errors. */
+ if (ret != -EEXIST) {
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+ }
+
+ /* Filename conflicts detected, try different names. */
+ for (int i = 0; i < 1024; i++) {
+ int len;
+
+ len = snprintf(buf, ARRAY_SIZE(buf), "%s%d", name, i);
+ if (len == 0 || len > BTRFS_NAME_LEN) {
+ error("failed to find an alternative name for image_root");
+ ret = -EINVAL;
+ goto abort;
+ }
+ ret = btrfs_link_subvolume(trans, fs_root,
+ btrfs_root_dirid(&fs_root->root_item),
+ buf, len, image_root);
+ if (!ret)
+ break;
+ if (ret != -EEXIST)
+ goto abort;
+ }
+commit:
+ ret = btrfs_commit_transaction(trans, fs_info->tree_root);
+ return ret;
+abort:
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+}
+
static int do_convert(const char *devname, u32 convert_flags, u32 nodesize,
const char *fslabel, int progress,
struct btrfs_mkfs_features *features, u16 csum_type,
@@ -1276,10 +1332,10 @@ static int do_convert(const char *devname, u32 convert_flags, u32 nodesize,
task_deinit(ctx.info);
}
- image_root = btrfs_mksubvol(root, subvol_name,
- CONV_IMAGE_SUBVOL_OBJECTID, true);
- if (!image_root) {
- error("unable to link subvolume %s", subvol_name);
+ ret = link_image_subvolume(image_root, subvol_name);
+ if (ret < 0) {
+ errno = -ret;
+ error("unable to link subvolume %s: %m", subvol_name);
goto fail;
}
@@ -1212,8 +1212,10 @@ static inline int is_fstree(u64 rootid)
void btrfs_uuid_to_key(const u8 *uuid, u8 type, struct btrfs_key *key);
/* inode.c */
-int check_dir_conflict(struct btrfs_root *root, char *name, int namelen,
- u64 dir, u64 index);
+int btrfs_find_free_dir_index(struct btrfs_root *root, u64 dir_ino,
+ u64 *ret_ino);
+int btrfs_check_dir_conflict(struct btrfs_root *root, const char *name,
+ int namelen, u64 dir, u64 index);
int btrfs_new_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 ino, u32 mode);
int btrfs_change_inode_flags(struct btrfs_trans_handle *trans,
@@ -1229,8 +1231,6 @@ int btrfs_add_orphan_item(struct btrfs_trans_handle *trans,
u64 ino);
int btrfs_mkdir(struct btrfs_trans_handle *trans, struct btrfs_root *root,
char *name, int namelen, u64 parent_ino, u64 *ino, int mode);
-struct btrfs_root *btrfs_mksubvol(struct btrfs_root *root, const char *base,
- u64 root_objectid, bool convert);
int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
struct btrfs_root *fs_root,
u64 dirid, u64 *objectid);
@@ -40,8 +40,8 @@
* Find a free inode index for later btrfs_add_link().
* Currently just search from the largest dir_index and +1.
*/
-static int btrfs_find_free_dir_index(struct btrfs_root *root, u64 dir_ino,
- u64 *ret_ino)
+int btrfs_find_free_dir_index(struct btrfs_root *root, u64 dir_ino,
+ u64 *ret_ino)
{
struct btrfs_path *path;
struct btrfs_key key;
@@ -93,8 +93,8 @@ out:
}
/* Check the dir_item/index conflicts before insert */
-int check_dir_conflict(struct btrfs_root *root, char *name, int namelen,
- u64 dir, u64 index)
+int btrfs_check_dir_conflict(struct btrfs_root *root, const char *name,
+ int namelen, u64 dir, u64 index)
{
struct btrfs_path *path;
struct btrfs_key key;
@@ -190,7 +190,7 @@ int btrfs_add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root,
goto out;
}
- ret = check_dir_conflict(root, name, namelen, parent_ino, ret_index);
+ ret = btrfs_check_dir_conflict(root, name, namelen, parent_ino, ret_index);
if (ret < 0 && !(ignore_existed && ret == -EEXIST))
goto out;
@@ -582,136 +582,6 @@ out:
return ret;
}
-struct btrfs_root *btrfs_mksubvol(struct btrfs_root *root,
- const char *base, u64 root_objectid,
- bool convert)
-{
- struct btrfs_trans_handle *trans;
- struct btrfs_fs_info *fs_info = root->fs_info;
- struct btrfs_root *tree_root = fs_info->tree_root;
- struct btrfs_root *new_root = NULL;
- struct btrfs_path path = { 0 };
- struct btrfs_inode_item *inode_item;
- struct extent_buffer *leaf;
- struct btrfs_key key;
- u64 dirid = btrfs_root_dirid(&root->root_item);
- u64 index = 2;
- char buf[BTRFS_NAME_LEN + 1]; /* for snprintf null */
- int len;
- int i;
- int ret;
-
- len = strlen(base);
- if (len == 0 || len > BTRFS_NAME_LEN)
- return NULL;
-
- key.objectid = dirid;
- key.type = BTRFS_DIR_INDEX_KEY;
- key.offset = (u64)-1;
-
- ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
- if (ret <= 0) {
- error("search for DIR_INDEX dirid %llu failed: %d",
- (unsigned long long)dirid, ret);
- goto fail;
- }
-
- if (path.slots[0] > 0) {
- path.slots[0]--;
- btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
- if (key.objectid == dirid && key.type == BTRFS_DIR_INDEX_KEY)
- index = key.offset + 1;
- }
- btrfs_release_path(&path);
-
- trans = btrfs_start_transaction(root, 1);
- if (IS_ERR(trans)) {
- ret = PTR_ERR(trans);
- errno = -ret;
- error_msg(ERROR_MSG_START_TRANS, "%m");
- goto fail;
- }
-
- key.objectid = dirid;
- key.type = BTRFS_INODE_ITEM_KEY;
- key.offset = 0;
-
- ret = btrfs_lookup_inode(trans, root, &path, &key, 1);
- if (ret) {
- error("search for INODE_ITEM %llu failed: %d",
- (unsigned long long)dirid, ret);
- goto fail;
- }
- leaf = path.nodes[0];
- inode_item = btrfs_item_ptr(leaf, path.slots[0],
- struct btrfs_inode_item);
-
- key.objectid = root_objectid;
- key.type = BTRFS_ROOT_ITEM_KEY;
- key.offset = (u64)-1;
-
- memcpy(buf, base, len);
- if (convert) {
- for (i = 0; i < 1024; i++) {
- ret = btrfs_insert_dir_item(trans, root, buf, len,
- dirid, &key, BTRFS_FT_DIR, index);
- if (ret != -EEXIST)
- break;
- len = snprintf(buf, ARRAY_SIZE(buf), "%s%d", base, i);
- if (len < 1 || len > BTRFS_NAME_LEN) {
- ret = -EINVAL;
- break;
- }
- }
- } else {
- ret = btrfs_insert_dir_item(trans, root, buf, len, dirid, &key,
- BTRFS_FT_DIR, index);
- }
- if (ret)
- goto fail;
-
- btrfs_set_inode_size(leaf, inode_item, len * 2 +
- btrfs_inode_size(leaf, inode_item));
- btrfs_mark_buffer_dirty(leaf);
- btrfs_release_path(&path);
-
- /* add the backref first */
- ret = btrfs_add_root_ref(trans, tree_root, root_objectid,
- BTRFS_ROOT_BACKREF_KEY,
- root->root_key.objectid,
- dirid, index, buf, len);
- if (ret) {
- error("unable to add root backref for %llu: %d",
- root->root_key.objectid, ret);
- goto fail;
- }
-
- /* now add the forward ref */
- ret = btrfs_add_root_ref(trans, tree_root, root->root_key.objectid,
- BTRFS_ROOT_REF_KEY, root_objectid,
- dirid, index, buf, len);
- if (ret) {
- error("unable to add root ref for %llu: %d",
- root->root_key.objectid, ret);
- goto fail;
- }
-
- ret = btrfs_commit_transaction(trans, root);
- if (ret) {
- errno = -ret;
- error_msg(ERROR_MSG_COMMIT_TRANS, "%m");
- goto fail;
- }
-
- new_root = btrfs_read_fs_root(fs_info, &key);
- if (IS_ERR(new_root)) {
- error("unable to fs read root: %lu", PTR_ERR(new_root));
- new_root = NULL;
- }
-fail:
- return new_root;
-}
-
/*
* Walk the tree of allocated inodes and find a hole.
*/
The function btrfs_mksubvol() is very different between btrfs-progs and kernel, the former version is really just linking a subvolume to another directory inode, but the kernel version is really to make a completely new subvolume. Instead of same-named function, introduce btrfs_link_subvolume() and use it to replace the old btrfs_mksubvol(). This is done by: - Introduce btrfs_link_subvolume() Which would do extra checks before doing any modification: * Make sure the target inode is a directory * Make sure no filename conflict Then do the linkage: * Add the dir_item/dir_index into the parent inode * Add the forward and backward root refs into tree root - Introduce link_image_subvolume() helper Currently btrfs_mksubvol() has a dedicated convert filename retry behavior, which is unnecessary and should be done by the convert code. Now move the filename retry behavior into the helper. - Remove btrfs_mksubvol() Since there is only one caller utilizing btrfs_mksubvol(), and it's now gone, we can remove the old btrfs_mksubvol(). Signed-off-by: Qu Wenruo <wqu@suse.com> --- check/main.c | 8 +-- common/root-tree-utils.c | 107 ++++++++++++++++++++++++++++++ common/root-tree-utils.h | 4 ++ convert/main.c | 64 ++++++++++++++++-- kernel-shared/ctree.h | 8 +-- kernel-shared/inode.c | 140 ++------------------------------------- 6 files changed, 184 insertions(+), 147 deletions(-)