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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2023-02-01 14:14:52 +01:00 committed by Christian Brauner (Microsoft)
parent fe15c26ee2
commit f2620f166e
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
4 changed files with 64 additions and 54 deletions

View File

@ -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)
{

View File

@ -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)))
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;
for_each_xattr_handler(handlers, handler) {
if (!handler->name || (handler->list && !handler->list(dentry)))
continue;
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);
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
err = posix_acl_listxattr(inode, &buffer, &remaining_size);
if (err)
return err;
read_lock(&xattrs->lock);
for (rbp = rb_first(&xattrs->rb_root); rbp; rbp = rb_next(rbp)) {

View File

@ -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);

View File

@ -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 */