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v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/fs.h>
  3#include <linux/gfp.h>
  4#include <linux/nfs.h>
  5#include <linux/nfs3.h>
  6#include <linux/nfs_fs.h>
  7#include <linux/posix_acl_xattr.h>
  8#include <linux/nfsacl.h>
  9
 10#include "internal.h"
 11#include "nfs3_fs.h"
 12
 13#define NFSDBG_FACILITY	NFSDBG_PROC
 14
 15/*
 16 * nfs3_prepare_get_acl, nfs3_complete_get_acl, nfs3_abort_get_acl: Helpers for
 17 * caching get_acl results in a race-free way.  See fs/posix_acl.c:get_acl()
 18 * for explanations.
 19 */
 20static void nfs3_prepare_get_acl(struct posix_acl **p)
 21{
 22	struct posix_acl *sentinel = uncached_acl_sentinel(current);
 23
 24	if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) {
 25		/* Not the first reader or sentinel already in place. */
 26	}
 27}
 28
 29static void nfs3_complete_get_acl(struct posix_acl **p, struct posix_acl *acl)
 30{
 31	struct posix_acl *sentinel = uncached_acl_sentinel(current);
 32
 33	/* Only cache the ACL if our sentinel is still in place. */
 34	posix_acl_dup(acl);
 35	if (cmpxchg(p, sentinel, acl) != sentinel)
 36		posix_acl_release(acl);
 37}
 38
 39static void nfs3_abort_get_acl(struct posix_acl **p)
 40{
 41	struct posix_acl *sentinel = uncached_acl_sentinel(current);
 42
 43	/* Remove our sentinel upon failure. */
 44	cmpxchg(p, sentinel, ACL_NOT_CACHED);
 45}
 46
 47struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
 48{
 49	struct nfs_server *server = NFS_SERVER(inode);
 50	struct page *pages[NFSACL_MAXPAGES] = { };
 51	struct nfs3_getaclargs args = {
 52		.fh = NFS_FH(inode),
 53		/* The xdr layer may allocate pages here. */
 54		.pages = pages,
 55	};
 56	struct nfs3_getaclres res = {
 57		NULL,
 58	};
 59	struct rpc_message msg = {
 60		.rpc_argp	= &args,
 61		.rpc_resp	= &res,
 62	};
 63	int status, count;
 64
 65	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 66		return ERR_PTR(-EOPNOTSUPP);
 67
 68	status = nfs_revalidate_inode(server, inode);
 69	if (status < 0)
 70		return ERR_PTR(status);
 71
 72	/*
 73	 * Only get the access acl when explicitly requested: We don't
 74	 * need it for access decisions, and only some applications use
 75	 * it. Applications which request the access acl first are not
 76	 * penalized from this optimization.
 77	 */
 78	if (type == ACL_TYPE_ACCESS)
 79		args.mask |= NFS_ACLCNT|NFS_ACL;
 80	if (S_ISDIR(inode->i_mode))
 81		args.mask |= NFS_DFACLCNT|NFS_DFACL;
 82	if (args.mask == 0)
 83		return NULL;
 84
 85	dprintk("NFS call getacl\n");
 86	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
 87	res.fattr = nfs_alloc_fattr();
 88	if (res.fattr == NULL)
 89		return ERR_PTR(-ENOMEM);
 90
 91	if (args.mask & NFS_ACL)
 92		nfs3_prepare_get_acl(&inode->i_acl);
 93	if (args.mask & NFS_DFACL)
 94		nfs3_prepare_get_acl(&inode->i_default_acl);
 95
 96	status = rpc_call_sync(server->client_acl, &msg, 0);
 97	dprintk("NFS reply getacl: %d\n", status);
 98
 99	/* pages may have been allocated at the xdr layer. */
100	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
101		__free_page(args.pages[count]);
102
103	switch (status) {
104		case 0:
105			status = nfs_refresh_inode(inode, res.fattr);
106			break;
107		case -EPFNOSUPPORT:
108		case -EPROTONOSUPPORT:
109			dprintk("NFS_V3_ACL extension not supported; disabling\n");
110			server->caps &= ~NFS_CAP_ACLS;
111		case -ENOTSUPP:
112			status = -EOPNOTSUPP;
113		default:
114			goto getout;
115	}
116	if ((args.mask & res.mask) != args.mask) {
117		status = -EIO;
118		goto getout;
119	}
120
121	if (res.acl_access != NULL) {
122		if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
123		    res.acl_access->a_count == 0) {
124			posix_acl_release(res.acl_access);
125			res.acl_access = NULL;
126		}
127	}
128
129	if (res.mask & NFS_ACL)
130		nfs3_complete_get_acl(&inode->i_acl, res.acl_access);
131	else
132		forget_cached_acl(inode, ACL_TYPE_ACCESS);
133
134	if (res.mask & NFS_DFACL)
135		nfs3_complete_get_acl(&inode->i_default_acl, res.acl_default);
136	else
137		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
138
139	nfs_free_fattr(res.fattr);
140	if (type == ACL_TYPE_ACCESS) {
141		posix_acl_release(res.acl_default);
142		return res.acl_access;
143	} else {
144		posix_acl_release(res.acl_access);
145		return res.acl_default;
146	}
147
148getout:
149	nfs3_abort_get_acl(&inode->i_acl);
150	nfs3_abort_get_acl(&inode->i_default_acl);
151	posix_acl_release(res.acl_access);
152	posix_acl_release(res.acl_default);
153	nfs_free_fattr(res.fattr);
154	return ERR_PTR(status);
155}
156
157static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
158		struct posix_acl *dfacl)
159{
160	struct nfs_server *server = NFS_SERVER(inode);
161	struct nfs_fattr *fattr;
162	struct page *pages[NFSACL_MAXPAGES];
163	struct nfs3_setaclargs args = {
164		.inode = inode,
165		.mask = NFS_ACL,
166		.acl_access = acl,
167		.pages = pages,
168	};
169	struct rpc_message msg = {
170		.rpc_argp	= &args,
171		.rpc_resp	= &fattr,
172	};
173	int status = 0;
174
175	if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
176		goto out;
177
178	status = -EOPNOTSUPP;
179	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
180		goto out;
181
182	/* We are doing this here because XDR marshalling does not
183	 * return any results, it BUGs. */
184	status = -ENOSPC;
185	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
186		goto out;
187	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
188		goto out;
189	if (S_ISDIR(inode->i_mode)) {
190		args.mask |= NFS_DFACL;
191		args.acl_default = dfacl;
192		args.len = nfsacl_size(acl, dfacl);
193	} else
194		args.len = nfsacl_size(acl, NULL);
195
196	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
197		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
198
199		status = -ENOMEM;
200		do {
201			args.pages[args.npages] = alloc_page(GFP_KERNEL);
202			if (args.pages[args.npages] == NULL)
203				goto out_freepages;
204			args.npages++;
205		} while (args.npages < npages);
206	}
207
208	dprintk("NFS call setacl\n");
209	status = -ENOMEM;
210	fattr = nfs_alloc_fattr();
211	if (fattr == NULL)
212		goto out_freepages;
213
214	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
215	msg.rpc_resp = fattr;
216	status = rpc_call_sync(server->client_acl, &msg, 0);
217	nfs_access_zap_cache(inode);
218	nfs_zap_acl_cache(inode);
219	dprintk("NFS reply setacl: %d\n", status);
220
221	switch (status) {
222		case 0:
223			status = nfs_refresh_inode(inode, fattr);
224			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
225			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
226			break;
227		case -EPFNOSUPPORT:
228		case -EPROTONOSUPPORT:
229			dprintk("NFS_V3_ACL SETACL RPC not supported"
230					"(will not retry)\n");
231			server->caps &= ~NFS_CAP_ACLS;
232		case -ENOTSUPP:
233			status = -EOPNOTSUPP;
234	}
235	nfs_free_fattr(fattr);
236out_freepages:
237	while (args.npages != 0) {
238		args.npages--;
239		__free_page(args.pages[args.npages]);
240	}
241out:
242	return status;
243}
244
245int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
246		struct posix_acl *dfacl)
247{
248	int ret;
249	ret = __nfs3_proc_setacls(inode, acl, dfacl);
250	return (ret == -EOPNOTSUPP) ? 0 : ret;
251
252}
253
254int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
255{
256	struct posix_acl *alloc = NULL, *dfacl = NULL;
257	int status;
258
259	if (S_ISDIR(inode->i_mode)) {
260		switch(type) {
261		case ACL_TYPE_ACCESS:
262			alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
263			if (IS_ERR(alloc))
264				goto fail;
265			break;
266
267		case ACL_TYPE_DEFAULT:
268			dfacl = acl;
269			alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
270			if (IS_ERR(alloc))
271				goto fail;
272			break;
273		}
274	}
275
276	if (acl == NULL) {
277		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
278		if (IS_ERR(alloc))
279			goto fail;
280	}
281	status = __nfs3_proc_setacls(inode, acl, dfacl);
282	posix_acl_release(alloc);
283	return status;
284
285fail:
286	return PTR_ERR(alloc);
287}
288
289const struct xattr_handler *nfs3_xattr_handlers[] = {
290	&posix_acl_access_xattr_handler,
291	&posix_acl_default_xattr_handler,
292	NULL,
293};
294
295static int
296nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
297		size_t size, ssize_t *result)
298{
299	struct posix_acl *acl;
300	char *p = data + *result;
301
302	acl = get_acl(inode, type);
303	if (IS_ERR_OR_NULL(acl))
304		return 0;
305
306	posix_acl_release(acl);
307
308	*result += strlen(name);
309	*result += 1;
310	if (!size)
311		return 0;
312	if (*result > size)
313		return -ERANGE;
314
315	strcpy(p, name);
316	return 0;
317}
318
319ssize_t
320nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
321{
322	struct inode *inode = d_inode(dentry);
323	ssize_t result = 0;
324	int error;
325
326	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
327			XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result);
328	if (error)
329		return error;
330
331	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
332			XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result);
333	if (error)
334		return error;
335	return result;
336}
v4.10.11
 
  1#include <linux/fs.h>
  2#include <linux/gfp.h>
  3#include <linux/nfs.h>
  4#include <linux/nfs3.h>
  5#include <linux/nfs_fs.h>
  6#include <linux/posix_acl_xattr.h>
  7#include <linux/nfsacl.h>
  8
  9#include "internal.h"
 10#include "nfs3_fs.h"
 11
 12#define NFSDBG_FACILITY	NFSDBG_PROC
 13
 14/*
 15 * nfs3_prepare_get_acl, nfs3_complete_get_acl, nfs3_abort_get_acl: Helpers for
 16 * caching get_acl results in a race-free way.  See fs/posix_acl.c:get_acl()
 17 * for explanations.
 18 */
 19static void nfs3_prepare_get_acl(struct posix_acl **p)
 20{
 21	struct posix_acl *sentinel = uncached_acl_sentinel(current);
 22
 23	if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) {
 24		/* Not the first reader or sentinel already in place. */
 25	}
 26}
 27
 28static void nfs3_complete_get_acl(struct posix_acl **p, struct posix_acl *acl)
 29{
 30	struct posix_acl *sentinel = uncached_acl_sentinel(current);
 31
 32	/* Only cache the ACL if our sentinel is still in place. */
 33	posix_acl_dup(acl);
 34	if (cmpxchg(p, sentinel, acl) != sentinel)
 35		posix_acl_release(acl);
 36}
 37
 38static void nfs3_abort_get_acl(struct posix_acl **p)
 39{
 40	struct posix_acl *sentinel = uncached_acl_sentinel(current);
 41
 42	/* Remove our sentinel upon failure. */
 43	cmpxchg(p, sentinel, ACL_NOT_CACHED);
 44}
 45
 46struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
 47{
 48	struct nfs_server *server = NFS_SERVER(inode);
 49	struct page *pages[NFSACL_MAXPAGES] = { };
 50	struct nfs3_getaclargs args = {
 51		.fh = NFS_FH(inode),
 52		/* The xdr layer may allocate pages here. */
 53		.pages = pages,
 54	};
 55	struct nfs3_getaclres res = {
 56		NULL,
 57	};
 58	struct rpc_message msg = {
 59		.rpc_argp	= &args,
 60		.rpc_resp	= &res,
 61	};
 62	int status, count;
 63
 64	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 65		return ERR_PTR(-EOPNOTSUPP);
 66
 67	status = nfs_revalidate_inode(server, inode);
 68	if (status < 0)
 69		return ERR_PTR(status);
 70
 71	/*
 72	 * Only get the access acl when explicitly requested: We don't
 73	 * need it for access decisions, and only some applications use
 74	 * it. Applications which request the access acl first are not
 75	 * penalized from this optimization.
 76	 */
 77	if (type == ACL_TYPE_ACCESS)
 78		args.mask |= NFS_ACLCNT|NFS_ACL;
 79	if (S_ISDIR(inode->i_mode))
 80		args.mask |= NFS_DFACLCNT|NFS_DFACL;
 81	if (args.mask == 0)
 82		return NULL;
 83
 84	dprintk("NFS call getacl\n");
 85	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
 86	res.fattr = nfs_alloc_fattr();
 87	if (res.fattr == NULL)
 88		return ERR_PTR(-ENOMEM);
 89
 90	if (args.mask & NFS_ACL)
 91		nfs3_prepare_get_acl(&inode->i_acl);
 92	if (args.mask & NFS_DFACL)
 93		nfs3_prepare_get_acl(&inode->i_default_acl);
 94
 95	status = rpc_call_sync(server->client_acl, &msg, 0);
 96	dprintk("NFS reply getacl: %d\n", status);
 97
 98	/* pages may have been allocated at the xdr layer. */
 99	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
100		__free_page(args.pages[count]);
101
102	switch (status) {
103		case 0:
104			status = nfs_refresh_inode(inode, res.fattr);
105			break;
106		case -EPFNOSUPPORT:
107		case -EPROTONOSUPPORT:
108			dprintk("NFS_V3_ACL extension not supported; disabling\n");
109			server->caps &= ~NFS_CAP_ACLS;
110		case -ENOTSUPP:
111			status = -EOPNOTSUPP;
112		default:
113			goto getout;
114	}
115	if ((args.mask & res.mask) != args.mask) {
116		status = -EIO;
117		goto getout;
118	}
119
120	if (res.acl_access != NULL) {
121		if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
122		    res.acl_access->a_count == 0) {
123			posix_acl_release(res.acl_access);
124			res.acl_access = NULL;
125		}
126	}
127
128	if (res.mask & NFS_ACL)
129		nfs3_complete_get_acl(&inode->i_acl, res.acl_access);
130	else
131		forget_cached_acl(inode, ACL_TYPE_ACCESS);
132
133	if (res.mask & NFS_DFACL)
134		nfs3_complete_get_acl(&inode->i_default_acl, res.acl_default);
135	else
136		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
137
138	nfs_free_fattr(res.fattr);
139	if (type == ACL_TYPE_ACCESS) {
140		posix_acl_release(res.acl_default);
141		return res.acl_access;
142	} else {
143		posix_acl_release(res.acl_access);
144		return res.acl_default;
145	}
146
147getout:
148	nfs3_abort_get_acl(&inode->i_acl);
149	nfs3_abort_get_acl(&inode->i_default_acl);
150	posix_acl_release(res.acl_access);
151	posix_acl_release(res.acl_default);
152	nfs_free_fattr(res.fattr);
153	return ERR_PTR(status);
154}
155
156static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
157		struct posix_acl *dfacl)
158{
159	struct nfs_server *server = NFS_SERVER(inode);
160	struct nfs_fattr *fattr;
161	struct page *pages[NFSACL_MAXPAGES];
162	struct nfs3_setaclargs args = {
163		.inode = inode,
164		.mask = NFS_ACL,
165		.acl_access = acl,
166		.pages = pages,
167	};
168	struct rpc_message msg = {
169		.rpc_argp	= &args,
170		.rpc_resp	= &fattr,
171	};
172	int status = 0;
173
174	if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
175		goto out;
176
177	status = -EOPNOTSUPP;
178	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
179		goto out;
180
181	/* We are doing this here because XDR marshalling does not
182	 * return any results, it BUGs. */
183	status = -ENOSPC;
184	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
185		goto out;
186	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
187		goto out;
188	if (S_ISDIR(inode->i_mode)) {
189		args.mask |= NFS_DFACL;
190		args.acl_default = dfacl;
191		args.len = nfsacl_size(acl, dfacl);
192	} else
193		args.len = nfsacl_size(acl, NULL);
194
195	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
196		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
197
198		status = -ENOMEM;
199		do {
200			args.pages[args.npages] = alloc_page(GFP_KERNEL);
201			if (args.pages[args.npages] == NULL)
202				goto out_freepages;
203			args.npages++;
204		} while (args.npages < npages);
205	}
206
207	dprintk("NFS call setacl\n");
208	status = -ENOMEM;
209	fattr = nfs_alloc_fattr();
210	if (fattr == NULL)
211		goto out_freepages;
212
213	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
214	msg.rpc_resp = fattr;
215	status = rpc_call_sync(server->client_acl, &msg, 0);
216	nfs_access_zap_cache(inode);
217	nfs_zap_acl_cache(inode);
218	dprintk("NFS reply setacl: %d\n", status);
219
220	switch (status) {
221		case 0:
222			status = nfs_refresh_inode(inode, fattr);
223			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
224			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
225			break;
226		case -EPFNOSUPPORT:
227		case -EPROTONOSUPPORT:
228			dprintk("NFS_V3_ACL SETACL RPC not supported"
229					"(will not retry)\n");
230			server->caps &= ~NFS_CAP_ACLS;
231		case -ENOTSUPP:
232			status = -EOPNOTSUPP;
233	}
234	nfs_free_fattr(fattr);
235out_freepages:
236	while (args.npages != 0) {
237		args.npages--;
238		__free_page(args.pages[args.npages]);
239	}
240out:
241	return status;
242}
243
244int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
245		struct posix_acl *dfacl)
246{
247	int ret;
248	ret = __nfs3_proc_setacls(inode, acl, dfacl);
249	return (ret == -EOPNOTSUPP) ? 0 : ret;
250
251}
252
253int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
254{
255	struct posix_acl *alloc = NULL, *dfacl = NULL;
256	int status;
257
258	if (S_ISDIR(inode->i_mode)) {
259		switch(type) {
260		case ACL_TYPE_ACCESS:
261			alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
262			if (IS_ERR(alloc))
263				goto fail;
264			break;
265
266		case ACL_TYPE_DEFAULT:
267			dfacl = acl;
268			alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
269			if (IS_ERR(alloc))
270				goto fail;
271			break;
272		}
273	}
274
275	if (acl == NULL) {
276		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
277		if (IS_ERR(alloc))
278			goto fail;
279	}
280	status = __nfs3_proc_setacls(inode, acl, dfacl);
281	posix_acl_release(alloc);
282	return status;
283
284fail:
285	return PTR_ERR(alloc);
286}
287
288const struct xattr_handler *nfs3_xattr_handlers[] = {
289	&posix_acl_access_xattr_handler,
290	&posix_acl_default_xattr_handler,
291	NULL,
292};
293
294static int
295nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
296		size_t size, ssize_t *result)
297{
298	struct posix_acl *acl;
299	char *p = data + *result;
300
301	acl = get_acl(inode, type);
302	if (IS_ERR_OR_NULL(acl))
303		return 0;
304
305	posix_acl_release(acl);
306
307	*result += strlen(name);
308	*result += 1;
309	if (!size)
310		return 0;
311	if (*result > size)
312		return -ERANGE;
313
314	strcpy(p, name);
315	return 0;
316}
317
318ssize_t
319nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
320{
321	struct inode *inode = d_inode(dentry);
322	ssize_t result = 0;
323	int error;
324
325	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
326			XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result);
327	if (error)
328		return error;
329
330	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
331			XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result);
332	if (error)
333		return error;
334	return result;
335}