Filipe David Borba Manana
2014-Apr-01 22:53 UTC
[PATCH] Btrfs: implement inode_operations callback tmpfile
This implements the tmpfile callback of struct inode_operations, introduced
in the linux kernel 3.11 [1], and implemented already by some filesystems.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
---
fs/btrfs/inode.c | 120 +++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 100 insertions(+), 20 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0ec8766..1a38ec7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5522,6 +5522,7 @@ static struct inode *btrfs_new_inode(struct
btrfs_trans_handle *trans,
struct btrfs_inode_ref *ref;
struct btrfs_key key[2];
u32 sizes[2];
+ int nitems = name ? 2 : 1;
unsigned long ptr;
int ret;
@@ -5541,7 +5542,7 @@ static struct inode *btrfs_new_inode(struct
btrfs_trans_handle *trans,
*/
inode->i_ino = objectid;
- if (dir) {
+ if (dir && name) {
trace_btrfs_inode_request(dir);
ret = btrfs_set_inode_index(dir, index);
@@ -5550,6 +5551,8 @@ static struct inode *btrfs_new_inode(struct
btrfs_trans_handle *trans,
iput(inode);
return ERR_PTR(ret);
}
+ } else if (dir) {
+ *index = 0;
}
/*
* index_cnt is ignored for everything but a dir,
@@ -5574,21 +5577,24 @@ static struct inode *btrfs_new_inode(struct
btrfs_trans_handle *trans,
btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
key[0].offset = 0;
- /*
- * Start new inodes with an inode_ref. This is slightly more
- * efficient for small numbers of hard links since they will
- * be packed into one item. Extended refs will kick in if we
- * add more hard links than can fit in the ref item.
- */
- key[1].objectid = objectid;
- btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
- key[1].offset = ref_objectid;
-
sizes[0] = sizeof(struct btrfs_inode_item);
- sizes[1] = name_len + sizeof(*ref);
+
+ if (name) {
+ /*
+ * Start new inodes with an inode_ref. This is slightly more
+ * efficient for small numbers of hard links since they will
+ * be packed into one item. Extended refs will kick in if we
+ * add more hard links than can fit in the ref item.
+ */
+ key[1].objectid = objectid;
+ btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
+ key[1].offset = ref_objectid;
+
+ sizes[1] = name_len + sizeof(*ref);
+ }
path->leave_spinning = 1;
- ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
+ ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
if (ret != 0)
goto fail;
@@ -5601,12 +5607,14 @@ static struct inode *btrfs_new_inode(struct
btrfs_trans_handle *trans,
sizeof(*inode_item));
fill_inode_item(trans, path->nodes[0], inode_item, inode);
- ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
- struct btrfs_inode_ref);
- btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
- btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
- ptr = (unsigned long)(ref + 1);
- write_extent_buffer(path->nodes[0], name, ptr, name_len);
+ if (name) {
+ ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
+ struct btrfs_inode_ref);
+ btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+ btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
+ ptr = (unsigned long)(ref + 1);
+ write_extent_buffer(path->nodes[0], name, ptr, name_len);
+ }
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
@@ -5642,7 +5650,7 @@ static struct inode *btrfs_new_inode(struct
btrfs_trans_handle *trans,
return inode;
fail:
- if (dir)
+ if (dir && name)
BTRFS_I(dir)->index_cnt--;
btrfs_free_path(path);
iput(inode);
@@ -5927,6 +5935,15 @@ static int btrfs_link(struct dentry *old_dentry, struct
inode *dir,
err = btrfs_update_inode(trans, root, inode);
if (err)
goto fail;
+ if (inode->i_nlink == 1) {
+ /*
+ * If new hard link count is 1, it's a file created
+ * with open(2) O_TMPFILE flag.
+ */
+ err = btrfs_orphan_del(trans, inode);
+ if (err)
+ goto fail;
+ }
d_instantiate(dentry, inode);
btrfs_log_new_name(trans, inode, NULL, parent);
}
@@ -8858,6 +8875,68 @@ static int btrfs_permission(struct inode *inode, int
mask)
return generic_permission(inode, mask);
}
+static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t
mode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = NULL;
+ u64 objectid;
+ u64 index;
+ int ret = 0;
+
+ /*
+ * 2 for inode item and ref
+ * 2 for dir items
+ * 1 for xattr if selinux is on
+ */
+ trans = btrfs_start_transaction(root, 5);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ ret = btrfs_find_free_ino(root, &objectid);
+ if (ret)
+ goto out;
+
+ inode = btrfs_new_inode(trans, root, dir, NULL, 0,
+ btrfs_ino(dir), objectid, mode, &index);
+ if (IS_ERR(inode)) {
+ ret = PTR_ERR(inode);
+ inode = NULL;
+ goto out;
+ }
+
+ ret = btrfs_init_inode_security(trans, inode, dir, NULL);
+ if (ret)
+ goto out;
+
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret)
+ goto out;
+
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+
+ ret = btrfs_orphan_add(trans, inode);
+ if (ret)
+ goto out;
+
+ d_tmpfile(dentry, inode);
+ mark_inode_dirty(inode);
+
+out:
+ btrfs_end_transaction(trans, root);
+ if (ret)
+ iput(inode);
+ btrfs_balance_delayed_items(root);
+ btrfs_btree_balance_dirty(root);
+
+ return ret;
+}
+
static const struct inode_operations btrfs_dir_inode_operations = {
.getattr = btrfs_getattr,
.lookup = btrfs_lookup,
@@ -8877,6 +8956,7 @@ static const struct inode_operations
btrfs_dir_inode_operations = {
.permission = btrfs_permission,
.get_acl = btrfs_get_acl,
.update_time = btrfs_update_time,
+ .tmpfile = btrfs_tmpfile,
};
static const struct inode_operations btrfs_dir_ro_inode_operations = {
.lookup = btrfs_lookup,
--
1.9.1
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