1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * linux/fs/ceph/acl.c
  4 *
  5 * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
  6 */
  7
  8#include <linux/ceph/ceph_debug.h>
  9#include <linux/fs.h>
 10#include <linux/string.h>
 11#include <linux/xattr.h>
 12#include <linux/posix_acl_xattr.h>
 13#include <linux/posix_acl.h>
 14#include <linux/sched.h>
 15#include <linux/slab.h>
 16
 17#include "super.h"
 18
 19static inline void ceph_set_cached_acl(struct inode *inode,
 20					int type, struct posix_acl *acl)
 21{
 22	struct ceph_inode_info *ci = ceph_inode(inode);
 23
 24	spin_lock(&ci->i_ceph_lock);
 25	if (__ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 0))
 26		set_cached_acl(inode, type, acl);
 27	else
 28		forget_cached_acl(inode, type);
 29	spin_unlock(&ci->i_ceph_lock);
 30}
 31
 32struct posix_acl *ceph_get_acl(struct inode *inode, int type)
 33{
 34	int size;
 35	unsigned int retry_cnt = 0;
 36	const char *name;
 37	char *value = NULL;
 38	struct posix_acl *acl;
 39
 40	switch (type) {
 41	case ACL_TYPE_ACCESS:
 42		name = XATTR_NAME_POSIX_ACL_ACCESS;
 43		break;
 44	case ACL_TYPE_DEFAULT:
 45		name = XATTR_NAME_POSIX_ACL_DEFAULT;
 46		break;
 47	default:
 48		BUG();
 49	}
 50
 51retry:
 52	size = __ceph_getxattr(inode, name, "", 0);
 53	if (size > 0) {
 54		value = kzalloc(size, GFP_NOFS);
 55		if (!value)
 56			return ERR_PTR(-ENOMEM);
 57		size = __ceph_getxattr(inode, name, value, size);
 58	}
 59
 60	if (size == -ERANGE && retry_cnt < 10) {
 61		retry_cnt++;
 62		kfree(value);
 63		value = NULL;
 64		goto retry;
 65	}
 66
 67	if (size > 0) {
 68		acl = posix_acl_from_xattr(&init_user_ns, value, size);
 69	} else if (size == -ENODATA || size == 0) {
 70		acl = NULL;
 71	} else {
 72		pr_err_ratelimited("get acl %llx.%llx failed, err=%d\n",
 73				   ceph_vinop(inode), size);
 74		acl = ERR_PTR(-EIO);
 75	}
 76
 77	kfree(value);
 78
 79	if (!IS_ERR(acl))
 80		ceph_set_cached_acl(inode, type, acl);
 81
 82	return acl;
 83}
 84
 85int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 86{
 87	int ret = 0, size = 0;
 88	const char *name = NULL;
 89	char *value = NULL;
 90	struct iattr newattrs;
 91	struct timespec64 old_ctime = inode->i_ctime;
 92	umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
 93
 94	if (ceph_snap(inode) != CEPH_NOSNAP) {
 95		ret = -EROFS;
 96		goto out;
 97	}
 98
 99	switch (type) {
100	case ACL_TYPE_ACCESS:
101		name = XATTR_NAME_POSIX_ACL_ACCESS;
102		if (acl) {
103			ret = posix_acl_update_mode(inode, &new_mode, &acl);
104			if (ret)
105				goto out;
106		}
107		break;
108	case ACL_TYPE_DEFAULT:
109		if (!S_ISDIR(inode->i_mode)) {
110			ret = acl ? -EINVAL : 0;
111			goto out;
112		}
113		name = XATTR_NAME_POSIX_ACL_DEFAULT;
114		break;
115	default:
116		ret = -EINVAL;
117		goto out;
118	}
119
120	if (acl) {
121		size = posix_acl_xattr_size(acl->a_count);
122		value = kmalloc(size, GFP_NOFS);
123		if (!value) {
124			ret = -ENOMEM;
125			goto out;
126		}
127
128		ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
129		if (ret < 0)
130			goto out_free;
131	}
132
133	if (new_mode != old_mode) {
134		newattrs.ia_ctime = current_time(inode);
135		newattrs.ia_mode = new_mode;
136		newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
137		ret = __ceph_setattr(inode, &newattrs);
138		if (ret)
139			goto out_free;
140	}
141
142	ret = __ceph_setxattr(inode, name, value, size, 0);
143	if (ret) {
144		if (new_mode != old_mode) {
145			newattrs.ia_ctime = old_ctime;
146			newattrs.ia_mode = old_mode;
147			newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
148			__ceph_setattr(inode, &newattrs);
149		}
150		goto out_free;
151	}
152
153	ceph_set_cached_acl(inode, type, acl);
154
155out_free:
156	kfree(value);
157out:
158	return ret;
159}
160
161int ceph_pre_init_acls(struct inode *dir, umode_t *mode,
162		       struct ceph_acl_sec_ctx *as_ctx)
163{
164	struct posix_acl *acl, *default_acl;
165	size_t val_size1 = 0, val_size2 = 0;
166	struct ceph_pagelist *pagelist = NULL;
167	void *tmp_buf = NULL;
168	int err;
169
170	err = posix_acl_create(dir, mode, &default_acl, &acl);
171	if (err)
172		return err;
173
174	if (acl) {
175		err = posix_acl_equiv_mode(acl, mode);
176		if (err < 0)
177			goto out_err;
178		if (err == 0) {
179			posix_acl_release(acl);
180			acl = NULL;
181		}
182	}
183
184	if (!default_acl && !acl)
185		return 0;
186
187	if (acl)
188		val_size1 = posix_acl_xattr_size(acl->a_count);
189	if (default_acl)
190		val_size2 = posix_acl_xattr_size(default_acl->a_count);
191
192	err = -ENOMEM;
193	tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL);
194	if (!tmp_buf)
195		goto out_err;
196	pagelist = ceph_pagelist_alloc(GFP_KERNEL);
197	if (!pagelist)
198		goto out_err;
199
200	err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
201	if (err)
202		goto out_err;
203
204	ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1);
205
206	if (acl) {
207		size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS);
208		err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8);
209		if (err)
210			goto out_err;
211		ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS,
212					    len);
213		err = posix_acl_to_xattr(&init_user_ns, acl,
214					 tmp_buf, val_size1);
215		if (err < 0)
216			goto out_err;
217		ceph_pagelist_encode_32(pagelist, val_size1);
218		ceph_pagelist_append(pagelist, tmp_buf, val_size1);
219	}
220	if (default_acl) {
221		size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT);
222		err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8);
223		if (err)
224			goto out_err;
225		ceph_pagelist_encode_string(pagelist,
226					  XATTR_NAME_POSIX_ACL_DEFAULT, len);
227		err = posix_acl_to_xattr(&init_user_ns, default_acl,
228					 tmp_buf, val_size2);
229		if (err < 0)
230			goto out_err;
231		ceph_pagelist_encode_32(pagelist, val_size2);
232		ceph_pagelist_append(pagelist, tmp_buf, val_size2);
233	}
234
235	kfree(tmp_buf);
236
237	as_ctx->acl = acl;
238	as_ctx->default_acl = default_acl;
239	as_ctx->pagelist = pagelist;
240	return 0;
241
242out_err:
243	posix_acl_release(acl);
244	posix_acl_release(default_acl);
245	kfree(tmp_buf);
246	if (pagelist)
247		ceph_pagelist_release(pagelist);
248	return err;
249}
250
251void ceph_init_inode_acls(struct inode *inode, struct ceph_acl_sec_ctx *as_ctx)
252{
253	if (!inode)
254		return;
255	ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, as_ctx->acl);
256	ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, as_ctx->default_acl);
257}