diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index a1c2e922a5dd6a68dcf2ff89deb1877c4ef07f79..754671a73333a6043bd88a4b272020d13c00d068 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -99,6 +99,29 @@ enum {
* range).
*/
BTRFS_INODE_COW_WRITE_ERROR,
+ /*
+ * Indicate this is a directory that points to a subvolume for which
+ * there is no root reference item. That's a case like the following:
+ *
+ * $ btrfs subvolume create /mnt/parent
+ * $ btrfs subvolume create /mnt/parent/child
+ * $ btrfs subvolume snapshot /mnt/parent /mnt/snap
+ *
+ * If subvolume "parent" is root 256, subvolume "child" is root 257 and
+ * snapshot "snap" is root 258, then there's no root reference item (key
+ * BTRFS_ROOT_REF_KEY in the root tree) for the subvolume "child"
+ * associated to root 258 (the snapshot) - there's only for the root
+ * of the "parent" subvolume (root 256). In the chunk root we have a
+ * (256 BTRFS_ROOT_REF_KEY 257) key but we don't have a
+ * (258 BTRFS_ROOT_REF_KEY 257) key - the sames goes for backrefs, we
+ * have a (257 BTRFS_ROOT_BACKREF_KEY 256) but we don't have a
+ * (257 BTRFS_ROOT_BACKREF_KEY 258) key.
+ *
+ * So when opening the "child" dentry from the snapshot's directory,
+ * we don't find a root ref item and we create a stub inode. This is
+ * done at new_simple_dir(), called from btrfs_lookup_dentry().
+ */
+ BTRFS_INODE_ROOT_STUB,
};
/* in memory btrfs inode */
@@ -106,10 +129,15 @@ struct btrfs_inode {
/* which subvolume this inode belongs to */
struct btrfs_root *root;
- /* key used to find this inode on disk. This is used by the code
- * to read in roots of subvolumes
+ /*
+ * This is either:
+ *
+ * 1) The objectid of the corresponding BTRFS_INODE_ITEM_KEY;
+ *
+ * 2) In case this a root stub inode (BTRFS_INODE_ROOT_STUB flag set),
+ * the ID of that root.
*/
- struct btrfs_key location;
+ u64 objectid;
/* Cached value of inode property 'compression'. */
u8 prop_compress;
@@ -340,10 +368,9 @@ static inline unsigned long btrfs_inode_hash(u64 objectid,
*/
static inline u64 btrfs_ino(const struct btrfs_inode *inode)
{
- u64 ino = inode->location.objectid;
+ u64 ino = inode->objectid;
- /* type == BTRFS_ROOT_ITEM_KEY: subvol dir */
- if (inode->location.type == BTRFS_ROOT_ITEM_KEY)
+ if (test_bit(BTRFS_INODE_ROOT_STUB, &inode->runtime_flags))
ino = inode->vfs_inode.i_ino;
return ino;
}
@@ -357,6 +384,14 @@ static inline u64 btrfs_ino(const struct btrfs_inode *inode)
#endif
+static inline void btrfs_get_inode_key(const struct btrfs_inode *inode,
+ struct btrfs_key *key)
+{
+ key->objectid = inode->objectid;
+ key->type = BTRFS_INODE_ITEM_KEY;
+ key->offset = 0;
+}
+
static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
{
i_size_write(&inode->vfs_inode, size);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 886ff6a72a9b05576869d6c975dadb2b2ea1cac9..f5d8e448a0c4ea8e8414f398fe3a05b91e676f30 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1944,9 +1944,7 @@ static int btrfs_init_btree_inode(struct super_block *sb)
extent_map_tree_init(&BTRFS_I(inode)->extent_tree);
BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root);
- BTRFS_I(inode)->location.objectid = BTRFS_BTREE_INODE_OBJECTID;
- BTRFS_I(inode)->location.type = 0;
- BTRFS_I(inode)->location.offset = 0;
+ BTRFS_I(inode)->objectid = BTRFS_BTREE_INODE_OBJECTID;
set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
__insert_inode_hash(inode, hash);
fs_info->btree_inode = inode;
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 9e81f89e76d851ead636c535521911cc99c8d1f8..5526e25ebb3fb8b1d54d867f0421ee19769a29a6 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -40,7 +40,7 @@ static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
if (parent) {
u64 parent_root_id;
- fid->parent_objectid = BTRFS_I(parent)->location.objectid;
+ fid->parent_objectid = BTRFS_I(parent)->objectid;
fid->parent_gen = parent->i_generation;
parent_root_id = btrfs_root_id(BTRFS_I(parent)->root);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 902ca1c64ff808990a7892b40fb1c0e23df6e2d9..c460322e3aa36eba28624840c5d186365c8f181a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3838,7 +3838,7 @@ static int btrfs_read_locked_inode(struct inode *inode,
return -ENOMEM;
}
- memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
+ btrfs_get_inode_key(BTRFS_I(inode), &location);
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret) {
@@ -4068,13 +4068,15 @@ static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
struct extent_buffer *leaf;
+ struct btrfs_key key;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
- ret = btrfs_lookup_inode(trans, inode->root, path, &inode->location, 1);
+ btrfs_get_inode_key(inode, &key);
+ ret = btrfs_lookup_inode(trans, inode->root, path, &key, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
@@ -4338,7 +4340,7 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
objectid = btrfs_root_id(inode->root);
} else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
- objectid = inode->location.objectid;
+ objectid = inode->objectid;
} else {
WARN_ON(1);
fscrypt_free_filename(&fname);
@@ -5580,9 +5582,7 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p)
struct btrfs_iget_args *args = p;
inode->i_ino = args->ino;
- BTRFS_I(inode)->location.objectid = args->ino;
- BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
- BTRFS_I(inode)->location.offset = 0;
+ BTRFS_I(inode)->objectid = args->ino;
BTRFS_I(inode)->root = btrfs_grab_root(args->root);
if (args->root && args->root == args->root->fs_info->tree_root &&
@@ -5596,7 +5596,7 @@ static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
- return args->ino == BTRFS_I(inode)->location.objectid &&
+ return args->ino == BTRFS_I(inode)->objectid &&
args->root == BTRFS_I(inode)->root;
}
@@ -5673,7 +5673,8 @@ static struct inode *new_simple_dir(struct inode *dir,
return ERR_PTR(-ENOMEM);
BTRFS_I(inode)->root = btrfs_grab_root(root);
- memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
+ BTRFS_I(inode)->objectid = key->objectid;
+ set_bit(BTRFS_INODE_ROOT_STUB, &BTRFS_I(inode)->runtime_flags);
set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
@@ -6149,7 +6150,7 @@ static int btrfs_insert_inode_locked(struct inode *inode)
{
struct btrfs_iget_args args;
- args.ino = BTRFS_I(inode)->location.objectid;
+ args.ino = BTRFS_I(inode)->objectid;
args.root = BTRFS_I(inode)->root;
return insert_inode_locked4(inode,
@@ -6256,7 +6257,6 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
struct btrfs_root *root;
struct btrfs_inode_item *inode_item;
- struct btrfs_key *location;
struct btrfs_path *path;
u64 objectid;
struct btrfs_inode_ref *ref;
@@ -6332,10 +6332,7 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
BTRFS_INODE_NODATASUM;
}
- location = &BTRFS_I(inode)->location;
- location->objectid = objectid;
- location->offset = 0;
- location->type = BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->objectid = objectid;
ret = btrfs_insert_inode_locked(inode);
if (ret < 0) {
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 28df28e50ad93dce0b43e0a0fa64bdbd1b8b34a5..79a5ccb27b921776a34defac77120b8ab9ce9e44 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1918,7 +1918,7 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct super_block *sb = inode->i_sb;
- struct btrfs_key upper_limit = BTRFS_I(inode)->location;
+ u64 upper_limit = BTRFS_I(inode)->objectid;
u64 treeid = btrfs_root_id(BTRFS_I(inode)->root);
u64 dirid = args->dirid;
unsigned long item_off;
@@ -1944,7 +1944,7 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
* If the bottom subvolume does not exist directly under upper_limit,
* construct the path in from the bottom up.
*/
- if (dirid != upper_limit.objectid) {
+ if (dirid != upper_limit) {
ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
root = btrfs_get_fs_root(fs_info, treeid, true);
@@ -2019,7 +2019,7 @@ static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
goto out_put;
}
- if (key.offset == upper_limit.objectid)
+ if (key.offset == upper_limit)
break;
if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
ret = -EACCES;
@@ -2140,7 +2140,7 @@ static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
inode = file_inode(file);
if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
- BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
+ BTRFS_I(inode)->objectid != BTRFS_FIRST_FREE_OBJECTID) {
/*
* The subvolume does not exist under fd with which this is
* called
diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index dce0387ef155b6ea72c0f62585fedd360d2219d5..b28a79935d8ef5ea3d64605534103fd93792cfc9 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -62,9 +62,7 @@ struct inode *btrfs_new_test_inode(void)
inode->i_mode = S_IFREG;
inode->i_ino = BTRFS_FIRST_FREE_OBJECTID;
- BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
- BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
- BTRFS_I(inode)->location.offset = 0;
+ BTRFS_I(inode)->objectid = BTRFS_FIRST_FREE_OBJECTID;
inode_init_owner(&nop_mnt_idmap, inode, NULL, S_IFREG);
return inode;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index e6294d2bb78b8a1b71d08da39e45f82ae98187ac..a2384455413e4d41abea5c074d45e59fc764b0c3 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -4254,8 +4254,10 @@ static int log_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode, bool inode_item_dropped)
{
struct btrfs_inode_item *inode_item;
+ struct btrfs_key key;
int ret;
+ btrfs_get_inode_key(inode, &key);
/*
* If we are doing a fast fsync and the inode was logged before in the
* current transaction, then we know the inode was previously logged and
@@ -4267,7 +4269,7 @@ static int log_inode_item(struct btrfs_trans_handle *trans,
* already exists can also result in unnecessarily splitting a leaf.
*/
if (!inode_item_dropped && inode->logged_trans == trans->transid) {
- ret = btrfs_search_slot(trans, log, &inode->location, path, 0, 1);
+ ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
ASSERT(ret <= 0);
if (ret > 0)
ret = -ENOENT;
@@ -4281,7 +4283,7 @@ static int log_inode_item(struct btrfs_trans_handle *trans,
* the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime
* flags and set ->logged_trans to 0.
*/
- ret = btrfs_insert_empty_item(trans, log, path, &inode->location,
+ ret = btrfs_insert_empty_item(trans, log, path, &key,
sizeof(*inode_item));
ASSERT(ret != -EEXIST);
}