1 // SPDX-License-Identifier: GPL-2.0
3 * (C) 2001 Clemson University and The University of Chicago
4 * Copyright 2018 Omnibond Systems, L.L.C.
6 * See COPYING in top-level directory.
10 * Linux VFS extended attribute operations.
14 #include "orangefs-kernel.h"
15 #include "orangefs-bufmap.h"
16 #include <linux/posix_acl_xattr.h>
17 #include <linux/xattr.h>
18 #include <linux/hashtable.h>
20 #define SYSTEM_ORANGEFS_KEY "system.pvfs2."
21 #define SYSTEM_ORANGEFS_KEY_LEN 13
24 * this function returns
25 * 0 if the key corresponding to name is not meant to be printed as part
27 * 1 if the key corresponding to name is meant to be returned as part of
29 * The ones that start SYSTEM_ORANGEFS_KEY are the ones to avoid printing.
31 static int is_reserved_key(const char *key, size_t size)
34 if (size < SYSTEM_ORANGEFS_KEY_LEN)
37 return strncmp(key, SYSTEM_ORANGEFS_KEY, SYSTEM_ORANGEFS_KEY_LEN) ? 1 : 0;
40 static inline int convert_to_internal_xattr_flags(int setxattr_flags)
42 int internal_flag = 0;
44 if (setxattr_flags & XATTR_REPLACE) {
45 /* Attribute must exist! */
46 internal_flag = ORANGEFS_XATTR_REPLACE;
47 } else if (setxattr_flags & XATTR_CREATE) {
48 /* Attribute must not exist */
49 internal_flag = ORANGEFS_XATTR_CREATE;
54 static unsigned int xattr_key(const char *key)
62 static struct orangefs_cached_xattr *find_cached_xattr(struct inode *inode,
65 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
66 struct orangefs_cached_xattr *cx;
68 struct hlist_node *tmp;
69 h = &orangefs_inode->xattr_cache[xattr_key(key)];
72 hlist_for_each_entry_safe(cx, tmp, h, node) {
73 /* if (!time_before(jiffies, cx->timeout)) {
78 if (!strcmp(cx->key, key))
85 * Tries to get a specified key's attributes of a given
86 * file into a user-specified buffer. Note that the getxattr
87 * interface allows for the users to probe the size of an
88 * extended attribute by passing in a value of 0 to size.
89 * Thus our return value is always the size of the attribute
90 * unless the key does not exist for the file and/or if
91 * there were errors in fetching the attribute value.
93 ssize_t orangefs_inode_getxattr(struct inode *inode, const char *name,
94 void *buffer, size_t size)
96 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
97 struct orangefs_kernel_op_s *new_op = NULL;
98 struct orangefs_cached_xattr *cx;
99 ssize_t ret = -ENOMEM;
104 gossip_debug(GOSSIP_XATTR_DEBUG,
105 "%s: name %s, buffer_size %zd\n",
106 __func__, name, size);
108 if (S_ISLNK(inode->i_mode))
111 if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
114 fsuid = from_kuid(&init_user_ns, current_fsuid());
115 fsgid = from_kgid(&init_user_ns, current_fsgid());
117 gossip_debug(GOSSIP_XATTR_DEBUG,
118 "getxattr on inode %pU, name %s "
119 "(uid %o, gid %o)\n",
120 get_khandle_from_ino(inode),
125 down_read(&orangefs_inode->xattr_sem);
127 cx = find_cached_xattr(inode, name);
128 if (cx && time_before(jiffies, cx->timeout)) {
129 if (cx->length == -1) {
137 if (cx->length > size) {
141 memcpy(buffer, cx->val, cx->length);
142 memset(buffer + cx->length, 0, size - cx->length);
148 new_op = op_alloc(ORANGEFS_VFS_OP_GETXATTR);
152 new_op->upcall.req.getxattr.refn = orangefs_inode->refn;
153 strcpy(new_op->upcall.req.getxattr.key, name);
156 * NOTE: Although keys are meant to be NULL terminated textual
157 * strings, I am going to explicitly pass the length just in case
158 * we change this later on...
160 new_op->upcall.req.getxattr.key_sz = strlen(name) + 1;
162 ret = service_operation(new_op, "orangefs_inode_getxattr",
163 get_interruptible_flag(inode));
165 if (ret == -ENOENT) {
167 gossip_debug(GOSSIP_XATTR_DEBUG,
168 "orangefs_inode_getxattr: inode %pU key %s"
169 " does not exist!\n",
170 get_khandle_from_ino(inode),
171 (char *)new_op->upcall.req.getxattr.key);
172 cx = kmalloc(sizeof *cx, GFP_KERNEL);
174 strcpy(cx->key, name);
176 cx->timeout = jiffies +
177 orangefs_getattr_timeout_msecs*HZ/1000;
178 hash_add(orangefs_inode->xattr_cache, &cx->node,
186 * Length returned includes null terminator.
188 length = new_op->downcall.resp.getxattr.val_sz;
191 * Just return the length of the queried attribute.
199 * Check to see if key length is > provided buffer size.
206 memcpy(buffer, new_op->downcall.resp.getxattr.val, length);
207 memset(buffer + length, 0, size - length);
208 gossip_debug(GOSSIP_XATTR_DEBUG,
209 "orangefs_inode_getxattr: inode %pU "
210 "key %s key_sz %d, val_len %d\n",
211 get_khandle_from_ino(inode),
213 upcall.req.getxattr.key,
215 upcall.req.getxattr.key_sz,
221 strcpy(cx->key, name);
222 memcpy(cx->val, buffer, length);
224 cx->timeout = jiffies + HZ;
226 cx = kmalloc(sizeof *cx, GFP_KERNEL);
228 strcpy(cx->key, name);
229 memcpy(cx->val, buffer, length);
231 cx->timeout = jiffies + HZ;
232 hash_add(orangefs_inode->xattr_cache, &cx->node,
240 up_read(&orangefs_inode->xattr_sem);
244 static int orangefs_inode_removexattr(struct inode *inode, const char *name,
247 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
248 struct orangefs_kernel_op_s *new_op = NULL;
249 struct orangefs_cached_xattr *cx;
250 struct hlist_head *h;
251 struct hlist_node *tmp;
254 if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
257 down_write(&orangefs_inode->xattr_sem);
258 new_op = op_alloc(ORANGEFS_VFS_OP_REMOVEXATTR);
262 new_op->upcall.req.removexattr.refn = orangefs_inode->refn;
264 * NOTE: Although keys are meant to be NULL terminated
265 * textual strings, I am going to explicitly pass the
266 * length just in case we change this later on...
268 strcpy(new_op->upcall.req.removexattr.key, name);
269 new_op->upcall.req.removexattr.key_sz = strlen(name) + 1;
271 gossip_debug(GOSSIP_XATTR_DEBUG,
272 "orangefs_inode_removexattr: key %s, key_sz %d\n",
273 (char *)new_op->upcall.req.removexattr.key,
274 (int)new_op->upcall.req.removexattr.key_sz);
276 ret = service_operation(new_op,
277 "orangefs_inode_removexattr",
278 get_interruptible_flag(inode));
279 if (ret == -ENOENT) {
281 * Request to replace a non-existent attribute is an error.
283 if (flags & XATTR_REPLACE)
289 gossip_debug(GOSSIP_XATTR_DEBUG,
290 "orangefs_inode_removexattr: returning %d\n", ret);
294 h = &orangefs_inode->xattr_cache[xattr_key(name)];
295 hlist_for_each_entry_safe(cx, tmp, h, node) {
296 if (!strcmp(cx->key, name)) {
297 hlist_del(&cx->node);
304 up_write(&orangefs_inode->xattr_sem);
309 * Tries to set an attribute for a given key on a file.
311 * Returns a -ve number on error and 0 on success. Key is text, but value
314 int orangefs_inode_setxattr(struct inode *inode, const char *name,
315 const void *value, size_t size, int flags)
317 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
318 struct orangefs_kernel_op_s *new_op;
319 int internal_flag = 0;
320 struct orangefs_cached_xattr *cx;
321 struct hlist_head *h;
322 struct hlist_node *tmp;
325 gossip_debug(GOSSIP_XATTR_DEBUG,
326 "%s: name %s, buffer_size %zd\n",
327 __func__, name, size);
329 if (size > ORANGEFS_MAX_XATTR_VALUELEN)
331 if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
334 internal_flag = convert_to_internal_xattr_flags(flags);
336 /* This is equivalent to a removexattr */
337 if (size == 0 && !value) {
338 gossip_debug(GOSSIP_XATTR_DEBUG,
339 "removing xattr (%s)\n",
341 return orangefs_inode_removexattr(inode, name, flags);
344 gossip_debug(GOSSIP_XATTR_DEBUG,
345 "setxattr on inode %pU, name %s\n",
346 get_khandle_from_ino(inode),
349 down_write(&orangefs_inode->xattr_sem);
350 new_op = op_alloc(ORANGEFS_VFS_OP_SETXATTR);
355 new_op->upcall.req.setxattr.refn = orangefs_inode->refn;
356 new_op->upcall.req.setxattr.flags = internal_flag;
358 * NOTE: Although keys are meant to be NULL terminated textual
359 * strings, I am going to explicitly pass the length just in
360 * case we change this later on...
362 strcpy(new_op->upcall.req.setxattr.keyval.key, name);
363 new_op->upcall.req.setxattr.keyval.key_sz = strlen(name) + 1;
364 memcpy(new_op->upcall.req.setxattr.keyval.val, value, size);
365 new_op->upcall.req.setxattr.keyval.val_sz = size;
367 gossip_debug(GOSSIP_XATTR_DEBUG,
368 "orangefs_inode_setxattr: key %s, key_sz %d "
370 (char *)new_op->upcall.req.setxattr.keyval.key,
371 (int)new_op->upcall.req.setxattr.keyval.key_sz,
374 ret = service_operation(new_op,
375 "orangefs_inode_setxattr",
376 get_interruptible_flag(inode));
378 gossip_debug(GOSSIP_XATTR_DEBUG,
379 "orangefs_inode_setxattr: returning %d\n",
382 /* when request is serviced properly, free req op struct */
385 h = &orangefs_inode->xattr_cache[xattr_key(name)];
386 hlist_for_each_entry_safe(cx, tmp, h, node) {
387 if (!strcmp(cx->key, name)) {
388 hlist_del(&cx->node);
395 up_write(&orangefs_inode->xattr_sem);
400 * Tries to get a specified object's keys into a user-specified buffer of a
401 * given size. Note that like the previous instances of xattr routines, this
402 * also allows you to pass in a NULL pointer and 0 size to probe the size for
403 * subsequent memory allocations. Thus our return value is always the size of
404 * all the keys unless there were errors in fetching the keys!
406 ssize_t orangefs_listxattr(struct dentry *dentry, char *buffer, size_t size)
408 struct inode *inode = dentry->d_inode;
409 struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
410 struct orangefs_kernel_op_s *new_op;
411 __u64 token = ORANGEFS_ITERATE_START;
412 ssize_t ret = -ENOMEM;
417 int returned_count = 0;
419 if (size > 0 && !buffer) {
420 gossip_err("%s: bogus NULL pointers\n", __func__);
424 down_read(&orangefs_inode->xattr_sem);
425 new_op = op_alloc(ORANGEFS_VFS_OP_LISTXATTR);
429 if (buffer && size > 0)
430 memset(buffer, 0, size);
434 new_op->upcall.req.listxattr.refn = orangefs_inode->refn;
435 new_op->upcall.req.listxattr.token = token;
436 new_op->upcall.req.listxattr.requested_count =
437 (size == 0) ? 0 : ORANGEFS_MAX_XATTR_LISTLEN;
438 ret = service_operation(new_op, __func__,
439 get_interruptible_flag(inode));
445 * This is a bit of a big upper limit, but I did not want to
446 * spend too much time getting this correct, since users end
447 * up allocating memory rather than us...
449 total = new_op->downcall.resp.listxattr.returned_count *
450 ORANGEFS_MAX_XATTR_NAMELEN;
454 returned_count = new_op->downcall.resp.listxattr.returned_count;
455 if (returned_count < 0 ||
456 returned_count > ORANGEFS_MAX_XATTR_LISTLEN) {
457 gossip_err("%s: impossible value for returned_count:%d:\n",
465 * Check to see how much can be fit in the buffer. Fit only whole keys.
467 for (i = 0; i < returned_count; i++) {
468 if (new_op->downcall.resp.listxattr.lengths[i] < 0 ||
469 new_op->downcall.resp.listxattr.lengths[i] >
470 ORANGEFS_MAX_XATTR_NAMELEN) {
471 gossip_err("%s: impossible value for lengths[%d]\n",
473 new_op->downcall.resp.listxattr.lengths[i]);
477 if (total + new_op->downcall.resp.listxattr.lengths[i] > size)
481 * Since many dumb programs try to setxattr() on our reserved
482 * xattrs this is a feeble attempt at defeating those by not
483 * listing them in the output of listxattr.. sigh
485 if (is_reserved_key(new_op->downcall.resp.listxattr.key +
487 new_op->downcall.resp.
488 listxattr.lengths[i])) {
489 gossip_debug(GOSSIP_XATTR_DEBUG, "Copying key %d -> %s\n",
490 i, new_op->downcall.resp.listxattr.key +
492 memcpy(buffer + total,
493 new_op->downcall.resp.listxattr.key + key_size,
494 new_op->downcall.resp.listxattr.lengths[i]);
495 total += new_op->downcall.resp.listxattr.lengths[i];
498 gossip_debug(GOSSIP_XATTR_DEBUG, "[RESERVED] key %d -> %s\n",
499 i, new_op->downcall.resp.listxattr.key +
502 key_size += new_op->downcall.resp.listxattr.lengths[i];
506 * Since the buffer was large enough, we might have to continue
507 * fetching more keys!
509 token = new_op->downcall.resp.listxattr.token;
510 if (token != ORANGEFS_ITERATE_END)
514 gossip_debug(GOSSIP_XATTR_DEBUG, "%s: returning %d"
515 " [size of buffer %ld] (filled in %d keys)\n",
517 ret ? (int)ret : (int)total,
524 up_read(&orangefs_inode->xattr_sem);
528 static int orangefs_xattr_set_default(const struct xattr_handler *handler,
529 struct dentry *unused,
536 return orangefs_inode_setxattr(inode, name, buffer, size, flags);
539 static int orangefs_xattr_get_default(const struct xattr_handler *handler,
540 struct dentry *unused,
546 return orangefs_inode_getxattr(inode, name, buffer, size);
550 static const struct xattr_handler orangefs_xattr_default_handler = {
551 .prefix = "", /* match any name => handlers called with full name */
552 .get = orangefs_xattr_get_default,
553 .set = orangefs_xattr_set_default,
556 const struct xattr_handler *orangefs_xattr_handlers[] = {
557 &posix_acl_access_xattr_handler,
558 &posix_acl_default_xattr_handler,
559 &orangefs_xattr_default_handler,