Unverified Commit f2620f16 authored by Christian Brauner's avatar Christian Brauner Committed by Christian Brauner (Microsoft)
Browse files

xattr: simplify listxattr helpers 



The generic_listxattr() and simple_xattr_list() helpers list xattrs and
contain duplicated code. Add two helpers that both generic_listxattr()
and simple_xattr_list() can use.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
parent fe15c26e

fs/posix_acl.c

+25 −0
Original line number Diff line number Diff line
@@ -957,6 +957,31 @@ set_posix_acl(struct mnt_idmap *idmap, struct dentry *dentry, 
}

EXPORT_SYMBOL(set_posix_acl);



int posix_acl_listxattr(struct inode *inode, char **buffer,

			ssize_t *remaining_size)

{

	int err;



	if (!IS_POSIXACL(inode))

		return 0;



	if (inode->i_acl) {

		err = xattr_list_one(buffer, remaining_size,

				     XATTR_NAME_POSIX_ACL_ACCESS);

		if (err)

			return err;

	}



	if (inode->i_default_acl) {

		err = xattr_list_one(buffer, remaining_size,

				     XATTR_NAME_POSIX_ACL_DEFAULT);

		if (err)

			return err;

	}



	return 0;

}



static bool

posix_acl_xattr_list(struct dentry *dentry)

{

fs/xattr.c

+33 −56
Original line number Diff line number Diff line
@@ -949,6 +949,21 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) 
	return error;

}



int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name)

{

	size_t len;



	len = strlen(name) + 1;

	if (*buffer) {

		if (*remaining_size < len)

			return -ERANGE;

		memcpy(*buffer, name, len);

		*buffer += len;

	}

	*remaining_size -= len;

	return 0;

}



/*

 * Combine the results of the list() operation from every xattr_handler in the

 * list.
@@ -957,33 +972,22 @@ ssize_t 
generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)

{

	const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr;

	unsigned int size = 0;

	ssize_t remaining_size = buffer_size;

	int err = 0;



	if (!buffer) {

		for_each_xattr_handler(handlers, handler) {

			if (!handler->name ||

			    (handler->list && !handler->list(dentry)))

				continue;

			size += strlen(handler->name) + 1;

		}

	} else {

		char *buf = buffer;

		size_t len;

	err = posix_acl_listxattr(d_inode(dentry), &buffer, &remaining_size);

	if (err)

		return err;



	for_each_xattr_handler(handlers, handler) {

			if (!handler->name ||

			    (handler->list && !handler->list(dentry)))

		if (!handler->name || (handler->list && !handler->list(dentry)))

			continue;

			len = strlen(handler->name);

			if (len + 1 > buffer_size)

				return -ERANGE;

			memcpy(buf, handler->name, len + 1);

			buf += len + 1;

			buffer_size -= len + 1;

		}

		size = buf - buffer;

		err = xattr_list_one(&buffer, &remaining_size, handler->name);

		if (err)

			return err;

	}

	return size;



	return err ? err : buffer_size - remaining_size;

}

EXPORT_SYMBOL(generic_listxattr);
@@ -1245,20 +1249,6 @@ static bool xattr_is_trusted(const char *name) 
	return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);

}



static int xattr_list_one(char **buffer, ssize_t *remaining_size,

			  const char *name)

{

	size_t len = strlen(name) + 1;

	if (*buffer) {

		if (*remaining_size < len)

			return -ERANGE;

		memcpy(*buffer, name, len);

		*buffer += len;

	}

	*remaining_size -= len;

	return 0;

}



/**

 * simple_xattr_list - list all xattr objects

 * @inode: inode from which to get the xattrs
@@ -1287,22 +1277,9 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, 
	ssize_t remaining_size = size;

	int err = 0;



#ifdef CONFIG_FS_POSIX_ACL

	if (IS_POSIXACL(inode)) {

		if (inode->i_acl) {

			err = xattr_list_one(&buffer, &remaining_size,

					     XATTR_NAME_POSIX_ACL_ACCESS);

	err = posix_acl_listxattr(inode, &buffer, &remaining_size);

	if (err)

		return err;

		}

		if (inode->i_default_acl) {

			err = xattr_list_one(&buffer, &remaining_size,

					     XATTR_NAME_POSIX_ACL_DEFAULT);

			if (err)

				return err;

		}

	}

#endif



	read_lock(&xattrs->lock);

	for (rbp = rb_first(&xattrs->rb_root); rbp; rbp = rb_next(rbp)) {

include/linux/posix_acl.h

+7 −0
Original line number Diff line number Diff line
@@ -106,6 +106,8 @@ struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap, 
			      struct dentry *dentry, const char *acl_name);

int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,

		   const char *acl_name);

int posix_acl_listxattr(struct inode *inode, char **buffer,

			ssize_t *remaining_size);

#else

static inline int posix_acl_chmod(struct mnt_idmap *idmap,

				  struct dentry *dentry, umode_t mode)
@@ -153,6 +155,11 @@ static inline int vfs_remove_acl(struct mnt_idmap *idmap, 
{

	return -EOPNOTSUPP;

}

static inline int posix_acl_listxattr(struct inode *inode, char **buffer,

				      ssize_t *remaining_size)

{

	return 0;

}

#endif /* CONFIG_FS_POSIX_ACL */



struct posix_acl *get_inode_acl(struct inode *inode, int type);

include/linux/xattr.h

+1 −0
Original line number Diff line number Diff line
@@ -109,5 +109,6 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, 
			  char *buffer, size_t size);

void simple_xattr_add(struct simple_xattrs *xattrs,

		      struct simple_xattr *new_xattr);

int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name);



#endif	/* _LINUX_XATTR_H */