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// SPDX-License-Identifier: LGPL-2.1
/*
* Copyright IBM Corporation, 2010
* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/uio.h>
#include <linux/posix_acl_xattr.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "fid.h"
#include "xattr.h"
ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name,
void *buffer, size_t buffer_size)
{
ssize_t retval;
u64 attr_size;
struct p9_fid *attr_fid;
struct kvec kvec = {.iov_base = buffer, .iov_len = buffer_size};
struct iov_iter to;
int err;
iov_iter_kvec(&to, ITER_DEST, &kvec, 1, buffer_size);
attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
if (IS_ERR(attr_fid)) {
retval = PTR_ERR(attr_fid);
p9_debug(P9_DEBUG_VFS, "p9_client_attrwalk failed %zd\n",
retval);
return retval;
}
if (attr_size > buffer_size) {
if (buffer_size)
retval = -ERANGE;
else if (attr_size > SSIZE_MAX)
retval = -EOVERFLOW;
else /* request to get the attr_size */
retval = attr_size;
} else {
iov_iter_truncate(&to, attr_size);
retval = p9_client_read(attr_fid, 0, &to, &err);
if (err)
retval = err;
}
p9_fid_put(attr_fid);
return retval;
}
/*
* v9fs_xattr_get()
*
* Copy an extended attribute into the buffer
* provided, or compute the buffer size required.
* Buffer is NULL to compute the size of the buffer required.
*
* Returns a negative error number on failure, or the number of bytes
* used / required on success.
*/
ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name,
void *buffer, size_t buffer_size)
{
struct p9_fid *fid;
int ret;
p9_debug(P9_DEBUG_VFS, "name = '%s' value_len = %zu\n",
name, buffer_size);
fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return PTR_ERR(fid);
ret = v9fs_fid_xattr_get(fid, name, buffer, buffer_size);
p9_fid_put(fid);
return ret;
}
/*
* v9fs_xattr_set()
*
* Create, replace or remove an extended attribute for this inode. Buffer
* is NULL to remove an existing extended attribute, and non-NULL to
* either replace an existing extended attribute, or create a new extended
* attribute. The flags XATTR_REPLACE and XATTR_CREATE
* specify that an extended attribute must exist and must not exist
* previous to the call, respectively.
*
* Returns 0, or a negative error number on failure.
*/
int v9fs_xattr_set(struct dentry *dentry, const char *name,
const void *value, size_t value_len, int flags)
{
int ret;
struct p9_fid *fid;
fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return PTR_ERR(fid);
ret = v9fs_fid_xattr_set(fid, name, value, value_len, flags);
p9_fid_put(fid);
return ret;
}
int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name,
const void *value, size_t value_len, int flags)
{
struct kvec kvec = {.iov_base = (void *)value, .iov_len = value_len};
struct iov_iter from;
int retval, err;
iov_iter_kvec(&from, ITER_SOURCE, &kvec, 1, value_len);
p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu flags = %d\n",
name, value_len, flags);
/* Clone it */
fid = clone_fid(fid);
if (IS_ERR(fid))
return PTR_ERR(fid);
/*
* On success fid points to xattr
*/
retval = p9_client_xattrcreate(fid, name, value_len, flags);
if (retval < 0)
p9_debug(P9_DEBUG_VFS, "p9_client_xattrcreate failed %d\n",
retval);
else
p9_client_write(fid, 0, &from, &retval);
err = p9_fid_put(fid);
if (!retval && err)
retval = err;
return retval;
}
ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
/* Txattrwalk with an empty string lists xattrs instead */
return v9fs_xattr_get(dentry, "", buffer, buffer_size);
}
static int v9fs_xattr_handler_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
const char *name, void *buffer, size_t size)
{
const char *full_name = xattr_full_name(handler, name);
return v9fs_xattr_get(dentry, full_name, buffer, size);
}
static int v9fs_xattr_handler_set(const struct xattr_handler *handler,
struct mnt_idmap *idmap,
struct dentry *dentry, struct inode *inode,
const char *name, const void *value,
size_t size, int flags)
{
const char *full_name = xattr_full_name(handler, name);
return v9fs_xattr_set(dentry, full_name, value, size, flags);
}
static const struct xattr_handler v9fs_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.get = v9fs_xattr_handler_get,
.set = v9fs_xattr_handler_set,
};
static const struct xattr_handler v9fs_xattr_trusted_handler = {
.prefix = XATTR_TRUSTED_PREFIX,
.get = v9fs_xattr_handler_get,
.set = v9fs_xattr_handler_set,
};
#ifdef CONFIG_9P_FS_SECURITY
static const struct xattr_handler v9fs_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.get = v9fs_xattr_handler_get,
.set = v9fs_xattr_handler_set,
};
#endif
const struct xattr_handler * const v9fs_xattr_handlers[] = {
&v9fs_xattr_user_handler,
&v9fs_xattr_trusted_handler,
#ifdef CONFIG_9P_FS_SECURITY
&v9fs_xattr_security_handler,
#endif
NULL
};
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