Btrfs: Pass transaction handle to security and ACL initialization functions

Pass transaction handle down to security and ACL initialization
functions, so we can avoid starting nested transactions

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

6 files changed, 96 insertions, 63 deletions

diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 3616042..1898f85 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -94,7 +94,8 @@ static int btrfs_xattr_get_acl(struct inode *inode, int type,
 /*
  * Needs to be called with fs_mutex held
  */
-static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+static int btrfs_set_acl(struct btrfs_trans_handle *trans,
+			 struct inode *inode, struct posix_acl *acl, int type)
 {
 	int ret, size = 0;
 	const char *name;
@@ -140,8 +141,7 @@ static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 			goto out;
 	}
 
-	ret = __btrfs_setxattr(inode, name, value, size, 0);
-
+	ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
 out:
 	kfree(value);
 
@@ -154,7 +154,7 @@ out:
 static int btrfs_xattr_set_acl(struct inode *inode, int type,
 			       const void *value, size_t size)
 {
-	int ret = 0;
+	int ret;
 	struct posix_acl *acl = NULL;
 
 	if (value) {
@@ -167,7 +167,7 @@ static int btrfs_xattr_set_acl(struct inode *inode, int type,
 		}
 	}
 
-	ret = btrfs_set_acl(inode, acl, type);
+	ret = btrfs_set_acl(NULL, inode, acl, type);
 
 	posix_acl_release(acl);
 
@@ -221,7 +221,8 @@ int btrfs_check_acl(struct inode *inode, int mask)
  * stuff has been fixed to work with that.  If the locking stuff changes, we
  * need to re-evaluate the acl locking stuff.
  */
-int btrfs_init_acl(struct inode *inode, struct inode *dir)
+int btrfs_init_acl(struct btrfs_trans_handle *trans,
+		   struct inode *inode, struct inode *dir)
 {
 	struct posix_acl *acl = NULL;
 	int ret = 0;
@@ -246,7 +247,8 @@ int btrfs_init_acl(struct inode *inode, struct inode *dir)
 		mode_t mode;
 
 		if (S_ISDIR(inode->i_mode)) {
-			ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
+			ret = btrfs_set_acl(trans, inode, acl,
+					    ACL_TYPE_DEFAULT);
 			if (ret)
 				goto failed;
 		}
@@ -261,7 +263,7 @@ int btrfs_init_acl(struct inode *inode, struct inode *dir)
 			inode->i_mode = mode;
 			if (ret > 0) {
 				/* we need an acl */
-				ret = btrfs_set_acl(inode, clone,
+				ret = btrfs_set_acl(trans, inode, clone,
 						    ACL_TYPE_ACCESS);
 			}
 		}
@@ -294,7 +296,7 @@ int btrfs_acl_chmod(struct inode *inode)
 
 	ret = posix_acl_chmod_masq(clone, inode->i_mode);
 	if (!ret)
-		ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
+		ret = btrfs_set_acl(NULL, inode, clone, ACL_TYPE_ACCESS);
 
 	posix_acl_release(clone);
 
@@ -320,7 +322,8 @@ int btrfs_acl_chmod(struct inode *inode)
 	return 0;
 }
 
-int btrfs_init_acl(struct inode *inode, struct inode *dir)
+int btrfs_init_acl(struct btrfs_trans_handle *trans,
+		   struct inode *inode, struct inode *dir)
 {
 	return 0;
 }
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index fcfbefb..a7cac21 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -310,6 +310,9 @@ struct btrfs_header {
 #define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
 					sizeof(struct btrfs_item) - \
 					sizeof(struct btrfs_file_extent_item))
+#define BTRFS_MAX_XATTR_SIZE(r)	(BTRFS_LEAF_DATA_SIZE(r) - \
+				 sizeof(struct btrfs_item) -\
+				 sizeof(struct btrfs_dir_item))
 
 
 /*
@@ -2201,9 +2204,10 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 			      struct btrfs_path *path,
 			      struct btrfs_dir_item *di);
 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, const char *name,
-			    u16 name_len, const void *data, u16 data_len,
-			    u64 dir);
+			    struct btrfs_root *root,
+			    struct btrfs_path *path, u64 objectid,
+			    const char *name, u16 name_len,
+			    const void *data, u16 data_len);
 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 					  struct btrfs_root *root,
 					  struct btrfs_path *path, u64 dir,
@@ -2382,7 +2386,8 @@ int btrfs_check_acl(struct inode *inode, int mask);
 #else
 #define btrfs_check_acl NULL
 #endif
-int btrfs_init_acl(struct inode *inode, struct inode *dir);
+int btrfs_init_acl(struct btrfs_trans_handle *trans,
+		   struct inode *inode, struct inode *dir);
 int btrfs_acl_chmod(struct inode *inode);
 
 /* relocation.c */
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index f3a6075..e9103b3 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -68,12 +68,12 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
  * into the tree
  */
 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, const char *name,
-			    u16 name_len, const void *data, u16 data_len,
-			    u64 dir)
+			    struct btrfs_root *root,
+			    struct btrfs_path *path, u64 objectid,
+			    const char *name, u16 name_len,
+			    const void *data, u16 data_len)
 {
 	int ret = 0;
-	struct btrfs_path *path;
 	struct btrfs_dir_item *dir_item;
 	unsigned long name_ptr, data_ptr;
 	struct btrfs_key key, location;
@@ -81,15 +81,11 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
 	struct extent_buffer *leaf;
 	u32 data_size;
 
-	key.objectid = dir;
+	BUG_ON(name_len + data_len > BTRFS_MAX_XATTR_SIZE(root));
+
+	key.objectid = objectid;
 	btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
 	key.offset = btrfs_name_hash(name, name_len);
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-	if (name_len + data_len + sizeof(struct btrfs_dir_item) >
-	    BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
-		return -ENOSPC;
 
 	data_size = sizeof(*dir_item) + name_len + data_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
@@ -117,7 +113,6 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
 	write_extent_buffer(leaf, data, data_ptr, data_len);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 
-	btrfs_free_path(path);
 	return ret;
 }
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index dcec42e..82740a3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -88,13 +88,14 @@ static noinline int cow_file_range(struct inode *inode,
 				   u64 start, u64 end, int *page_started,
 				   unsigned long *nr_written, int unlock);
 
-static int btrfs_init_inode_security(struct inode *inode,  struct inode *dir)
+static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
+				     struct inode *inode,  struct inode *dir)
 {
 	int err;
 
-	err = btrfs_init_acl(inode, dir);
+	err = btrfs_init_acl(trans, inode, dir);
 	if (!err)
-		err = btrfs_xattr_security_init(inode, dir);
+		err = btrfs_xattr_security_init(trans, inode, dir);
 	return err;
 }
 
@@ -4296,7 +4297,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
 	if (IS_ERR(inode))
 		goto out_unlock;
 
-	err = btrfs_init_inode_security(inode, dir);
+	err = btrfs_init_inode_security(trans, inode, dir);
 	if (err) {
 		drop_inode = 1;
 		goto out_unlock;
@@ -4367,7 +4368,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 	if (IS_ERR(inode))
 		goto out_unlock;
 
-	err = btrfs_init_inode_security(inode, dir);
+	err = btrfs_init_inode_security(trans, inode, dir);
 	if (err) {
 		drop_inode = 1;
 		goto out_unlock;
@@ -4500,7 +4501,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
 	drop_on_err = 1;
 
-	err = btrfs_init_inode_security(inode, dir);
+	err = btrfs_init_inode_security(trans, inode, dir);
 	if (err)
 		goto out_fail;
 
@@ -5660,7 +5661,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 	if (IS_ERR(inode))
 		goto out_unlock;
 
-	err = btrfs_init_inode_security(inode, dir);
+	err = btrfs_init_inode_security(trans, inode, dir);
 	if (err) {
 		drop_inode = 1;
 		goto out_unlock;
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index b6dd596..193b58f 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -85,22 +85,23 @@ out:
 	return ret;
 }
 
-int __btrfs_setxattr(struct inode *inode, const char *name,
-			    const void *value, size_t size, int flags)
+static int do_setxattr(struct btrfs_trans_handle *trans,
+		       struct inode *inode, const char *name,
+		       const void *value, size_t size, int flags)
 {
 	struct btrfs_dir_item *di;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct btrfs_trans_handle *trans;
 	struct btrfs_path *path;
-	int ret = 0, mod = 0;
+	size_t name_len = strlen(name);
+	int ret = 0;
+
+	if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
+		return -ENOSPC;
 
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
 
-	trans = btrfs_join_transaction(root, 1);
-	btrfs_set_trans_block_group(trans, inode);
-
 	/* first lets see if we already have this xattr */
 	di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name,
 				strlen(name), -1);
@@ -118,15 +119,12 @@ int __btrfs_setxattr(struct inode *inode, const char *name,
 		}
 
 		ret = btrfs_delete_one_dir_name(trans, root, path, di);
-		if (ret)
-			goto out;
+		BUG_ON(ret);
 		btrfs_release_path(root, path);
 
 		/* if we don't have a value then we are removing the xattr */
-		if (!value) {
-			mod = 1;
+		if (!value)
 			goto out;
-		}
 	} else {
 		btrfs_release_path(root, path);
 
@@ -138,20 +136,45 @@ int __btrfs_setxattr(struct inode *inode, const char *name,
 	}
 
 	/* ok we have to create a completely new xattr */
-	ret = btrfs_insert_xattr_item(trans, root, name, strlen(name),
-				      value, size, inode->i_ino);
+	ret = btrfs_insert_xattr_item(trans, root, path, inode->i_ino,
+				      name, name_len, value, size);
+	BUG_ON(ret);
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+int __btrfs_setxattr(struct btrfs_trans_handle *trans,
+		     struct inode *inode, const char *name,
+		     const void *value, size_t size, int flags)
+{
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	int ret;
+
+	if (trans)
+		return do_setxattr(trans, inode, name, value, size, flags);
+
+	ret = btrfs_reserve_metadata_space(root, 2);
 	if (ret)
-		goto out;
-	mod = 1;
+		return ret;
 
-out:
-	if (mod) {
-		inode->i_ctime = CURRENT_TIME;
-		ret = btrfs_update_inode(trans, root, inode);
+	trans = btrfs_start_transaction(root, 1);
+	if (!trans) {
+		ret = -ENOMEM;
+		goto out;
 	}
+	btrfs_set_trans_block_group(trans, inode);
 
-	btrfs_end_transaction(trans, root);
-	btrfs_free_path(path);
+	ret = do_setxattr(trans, inode, name, value, size, flags);
+	if (ret)
+		goto out;
+
+	inode->i_ctime = CURRENT_TIME;
+	ret = btrfs_update_inode(trans, root, inode);
+	BUG_ON(ret);
+out:
+	btrfs_end_transaction_throttle(trans, root);
+	btrfs_unreserve_metadata_space(root, 2);
 	return ret;
 }
 
@@ -314,7 +337,9 @@ int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 
 	if (size == 0)
 		value = "";  /* empty EA, do not remove */
-	return __btrfs_setxattr(dentry->d_inode, name, value, size, flags);
+
+	return __btrfs_setxattr(NULL, dentry->d_inode, name, value, size,
+				flags);
 }
 
 int btrfs_removexattr(struct dentry *dentry, const char *name)
@@ -329,10 +354,13 @@ int btrfs_removexattr(struct dentry *dentry, const char *name)
 
 	if (!btrfs_is_valid_xattr(name))
 		return -EOPNOTSUPP;
-	return __btrfs_setxattr(dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
+
+	return __btrfs_setxattr(NULL, dentry->d_inode, name, NULL, 0,
+				XATTR_REPLACE);
 }
 
-int btrfs_xattr_security_init(struct inode *inode, struct inode *dir)
+int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
+			      struct inode *inode, struct inode *dir)
 {
 	int err;
 	size_t len;
@@ -354,7 +382,7 @@ int btrfs_xattr_security_init(struct inode *inode, struct inode *dir)
 	} else {
 		strcpy(name, XATTR_SECURITY_PREFIX);
 		strcpy(name + XATTR_SECURITY_PREFIX_LEN, suffix);
-		err = __btrfs_setxattr(inode, name, value, len, 0);
+		err = __btrfs_setxattr(trans, inode, name, value, len, 0);
 		kfree(name);
 	}
 
diff --git a/fs/btrfs/xattr.h b/fs/btrfs/xattr.h
index c71e9c3..721efa0 100644
--- a/fs/btrfs/xattr.h
+++ b/fs/btrfs/xattr.h
@@ -27,15 +27,16 @@ extern struct xattr_handler *btrfs_xattr_handlers[];
 
 extern ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
 		void *buffer, size_t size);
-extern int __btrfs_setxattr(struct inode *inode, const char *name,
-		const void *value, size_t size, int flags);
-
+extern int __btrfs_setxattr(struct btrfs_trans_handle *trans,
+			    struct inode *inode, const char *name,
+			    const void *value, size_t size, int flags);
 extern ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
 		void *buffer, size_t size);
 extern int btrfs_setxattr(struct dentry *dentry, const char *name,
 		const void *value, size_t size, int flags);
 extern int btrfs_removexattr(struct dentry *dentry, const char *name);
 
-extern int btrfs_xattr_security_init(struct inode *inode, struct inode *dir);
+extern int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
+				     struct inode *inode, struct inode *dir);
 
 #endif /* __XATTR__ */