2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
11 #include <linux/pagemap.h>
12 #include <linux/file.h>
13 #include <linux/gfp.h>
14 #include <linux/sched.h>
15 #include <linux/namei.h>
17 #if BITS_PER_LONG >= 64
18 static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
23 static inline u64 fuse_dentry_time(struct dentry *entry)
29 * On 32 bit archs store the high 32 bits of time in d_fsdata
31 static void fuse_dentry_settime(struct dentry *entry, u64 time)
34 entry->d_fsdata = (void *) (unsigned long) (time >> 32);
37 static u64 fuse_dentry_time(struct dentry *entry)
39 return (u64) entry->d_time +
40 ((u64) (unsigned long) entry->d_fsdata << 32);
45 * FUSE caches dentries and attributes with separate timeout. The
46 * time in jiffies until the dentry/attributes are valid is stored in
47 * dentry->d_time and fuse_inode->i_time respectively.
51 * Calculate the time in jiffies until a dentry/attributes are valid
53 static u64 time_to_jiffies(unsigned long sec, unsigned long nsec)
56 struct timespec ts = {sec, nsec};
57 return get_jiffies_64() + timespec_to_jiffies(&ts);
63 * Set dentry and possibly attribute timeouts from the lookup/mk*
66 static void fuse_change_timeout(struct dentry *entry, struct fuse_entry_out *o)
68 fuse_dentry_settime(entry,
69 time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
71 get_fuse_inode(entry->d_inode)->i_time =
72 time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
76 * Mark the attributes as stale, so that at the next call to
77 * ->getattr() they will be fetched from userspace
79 void fuse_invalidate_attr(struct inode *inode)
81 get_fuse_inode(inode)->i_time = 0;
85 * Just mark the entry as stale, so that a next attempt to look it up
86 * will result in a new lookup call to userspace
88 * This is called when a dentry is about to become negative and the
89 * timeout is unknown (unlink, rmdir, rename and in some cases
92 static void fuse_invalidate_entry_cache(struct dentry *entry)
94 fuse_dentry_settime(entry, 0);
98 * Same as fuse_invalidate_entry_cache(), but also try to remove the
99 * dentry from the hash
101 static void fuse_invalidate_entry(struct dentry *entry)
104 fuse_invalidate_entry_cache(entry);
107 static void fuse_lookup_init(struct fuse_req *req, struct inode *dir,
108 struct dentry *entry,
109 struct fuse_entry_out *outarg)
111 req->in.h.opcode = FUSE_LOOKUP;
112 req->in.h.nodeid = get_node_id(dir);
114 req->in.args[0].size = entry->d_name.len + 1;
115 req->in.args[0].value = entry->d_name.name;
116 req->out.numargs = 1;
117 req->out.args[0].size = sizeof(struct fuse_entry_out);
118 req->out.args[0].value = outarg;
122 * Check whether the dentry is still valid
124 * If the entry validity timeout has expired and the dentry is
125 * positive, try to redo the lookup. If the lookup results in a
126 * different inode, then let the VFS invalidate the dentry and redo
127 * the lookup once more. If the lookup results in the same inode,
128 * then refresh the attributes, timeouts and mark the dentry valid.
130 static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
132 struct inode *inode = entry->d_inode;
134 if (inode && is_bad_inode(inode))
136 else if (fuse_dentry_time(entry) < get_jiffies_64()) {
138 struct fuse_entry_out outarg;
139 struct fuse_conn *fc;
140 struct fuse_req *req;
141 struct fuse_req *forget_req;
142 struct dentry *parent;
144 /* For negative dentries, always do a fresh lookup */
148 fc = get_fuse_conn(inode);
149 req = fuse_get_req(fc);
153 forget_req = fuse_get_req(fc);
154 if (IS_ERR(forget_req)) {
155 fuse_put_request(fc, req);
159 parent = dget_parent(entry);
160 fuse_lookup_init(req, parent->d_inode, entry, &outarg);
161 request_send(fc, req);
163 err = req->out.h.error;
164 fuse_put_request(fc, req);
165 /* Zero nodeid is same as -ENOENT */
166 if (!err && !outarg.nodeid)
169 struct fuse_inode *fi = get_fuse_inode(inode);
170 if (outarg.nodeid != get_node_id(inode)) {
171 fuse_send_forget(fc, forget_req,
175 spin_lock(&fc->lock);
177 spin_unlock(&fc->lock);
179 fuse_put_request(fc, forget_req);
180 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
183 fuse_change_attributes(inode, &outarg.attr);
184 fuse_change_timeout(entry, &outarg);
189 static int invalid_nodeid(u64 nodeid)
191 return !nodeid || nodeid == FUSE_ROOT_ID;
194 static struct dentry_operations fuse_dentry_operations = {
195 .d_revalidate = fuse_dentry_revalidate,
198 int fuse_valid_type(int m)
200 return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
201 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
205 * Add a directory inode to a dentry, ensuring that no other dentry
206 * refers to this inode. Called with fc->inst_mutex.
208 static int fuse_d_add_directory(struct dentry *entry, struct inode *inode)
210 struct dentry *alias = d_find_alias(inode);
212 /* This tries to shrink the subtree below alias */
213 fuse_invalidate_entry(alias);
215 if (!list_empty(&inode->i_dentry))
222 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
223 struct nameidata *nd)
226 struct fuse_entry_out outarg;
227 struct inode *inode = NULL;
228 struct fuse_conn *fc = get_fuse_conn(dir);
229 struct fuse_req *req;
230 struct fuse_req *forget_req;
232 if (entry->d_name.len > FUSE_NAME_MAX)
233 return ERR_PTR(-ENAMETOOLONG);
235 req = fuse_get_req(fc);
237 return ERR_PTR(PTR_ERR(req));
239 forget_req = fuse_get_req(fc);
240 if (IS_ERR(forget_req)) {
241 fuse_put_request(fc, req);
242 return ERR_PTR(PTR_ERR(forget_req));
245 fuse_lookup_init(req, dir, entry, &outarg);
246 request_send(fc, req);
247 err = req->out.h.error;
248 fuse_put_request(fc, req);
249 /* Zero nodeid is same as -ENOENT, but with valid timeout */
250 if (!err && outarg.nodeid &&
251 (invalid_nodeid(outarg.nodeid) ||
252 !fuse_valid_type(outarg.attr.mode)))
254 if (!err && outarg.nodeid) {
255 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
258 fuse_send_forget(fc, forget_req, outarg.nodeid, 1);
259 return ERR_PTR(-ENOMEM);
262 fuse_put_request(fc, forget_req);
263 if (err && err != -ENOENT)
266 if (inode && S_ISDIR(inode->i_mode)) {
267 mutex_lock(&fc->inst_mutex);
268 err = fuse_d_add_directory(entry, inode);
269 mutex_unlock(&fc->inst_mutex);
277 entry->d_op = &fuse_dentry_operations;
279 fuse_change_timeout(entry, &outarg);
281 fuse_invalidate_entry_cache(entry);
286 * Synchronous release for the case when something goes wrong in CREATE_OPEN
288 static void fuse_sync_release(struct fuse_conn *fc, struct fuse_file *ff,
289 u64 nodeid, int flags)
291 struct fuse_req *req;
293 req = fuse_release_fill(ff, nodeid, flags, FUSE_RELEASE);
295 request_send(fc, req);
296 fuse_put_request(fc, req);
300 * Atomic create+open operation
302 * If the filesystem doesn't support this, then fall back to separate
303 * 'mknod' + 'open' requests.
305 static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
306 struct nameidata *nd)
310 struct fuse_conn *fc = get_fuse_conn(dir);
311 struct fuse_req *req;
312 struct fuse_req *forget_req;
313 struct fuse_open_in inarg;
314 struct fuse_open_out outopen;
315 struct fuse_entry_out outentry;
316 struct fuse_file *ff;
318 int flags = nd->intent.open.flags - 1;
323 forget_req = fuse_get_req(fc);
324 if (IS_ERR(forget_req))
325 return PTR_ERR(forget_req);
327 req = fuse_get_req(fc);
330 goto out_put_forget_req;
333 ff = fuse_file_alloc();
335 goto out_put_request;
338 memset(&inarg, 0, sizeof(inarg));
341 req->in.h.opcode = FUSE_CREATE;
342 req->in.h.nodeid = get_node_id(dir);
344 req->in.args[0].size = sizeof(inarg);
345 req->in.args[0].value = &inarg;
346 req->in.args[1].size = entry->d_name.len + 1;
347 req->in.args[1].value = entry->d_name.name;
348 req->out.numargs = 2;
349 req->out.args[0].size = sizeof(outentry);
350 req->out.args[0].value = &outentry;
351 req->out.args[1].size = sizeof(outopen);
352 req->out.args[1].value = &outopen;
353 request_send(fc, req);
354 err = req->out.h.error;
362 if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
365 fuse_put_request(fc, req);
366 inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
369 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
371 fuse_sync_release(fc, ff, outentry.nodeid, flags);
372 fuse_send_forget(fc, forget_req, outentry.nodeid, 1);
375 fuse_put_request(fc, forget_req);
376 d_instantiate(entry, inode);
377 fuse_change_timeout(entry, &outentry);
378 file = lookup_instantiate_filp(nd, entry, generic_file_open);
381 fuse_sync_release(fc, ff, outentry.nodeid, flags);
382 return PTR_ERR(file);
384 fuse_finish_open(inode, file, ff, &outopen);
390 fuse_put_request(fc, req);
392 fuse_put_request(fc, forget_req);
397 * Code shared between mknod, mkdir, symlink and link
399 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
400 struct inode *dir, struct dentry *entry,
403 struct fuse_entry_out outarg;
406 struct fuse_req *forget_req;
408 forget_req = fuse_get_req(fc);
409 if (IS_ERR(forget_req)) {
410 fuse_put_request(fc, req);
411 return PTR_ERR(forget_req);
414 req->in.h.nodeid = get_node_id(dir);
415 req->out.numargs = 1;
416 req->out.args[0].size = sizeof(outarg);
417 req->out.args[0].value = &outarg;
418 request_send(fc, req);
419 err = req->out.h.error;
420 fuse_put_request(fc, req);
422 goto out_put_forget_req;
425 if (invalid_nodeid(outarg.nodeid))
426 goto out_put_forget_req;
428 if ((outarg.attr.mode ^ mode) & S_IFMT)
429 goto out_put_forget_req;
431 inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
434 fuse_send_forget(fc, forget_req, outarg.nodeid, 1);
437 fuse_put_request(fc, forget_req);
439 if (S_ISDIR(inode->i_mode)) {
440 struct dentry *alias;
441 mutex_lock(&fc->inst_mutex);
442 alias = d_find_alias(inode);
444 /* New directory must have moved since mkdir */
445 mutex_unlock(&fc->inst_mutex);
450 d_instantiate(entry, inode);
451 mutex_unlock(&fc->inst_mutex);
453 d_instantiate(entry, inode);
455 fuse_change_timeout(entry, &outarg);
456 fuse_invalidate_attr(dir);
460 fuse_put_request(fc, forget_req);
464 static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
467 struct fuse_mknod_in inarg;
468 struct fuse_conn *fc = get_fuse_conn(dir);
469 struct fuse_req *req = fuse_get_req(fc);
473 memset(&inarg, 0, sizeof(inarg));
475 inarg.rdev = new_encode_dev(rdev);
476 req->in.h.opcode = FUSE_MKNOD;
478 req->in.args[0].size = sizeof(inarg);
479 req->in.args[0].value = &inarg;
480 req->in.args[1].size = entry->d_name.len + 1;
481 req->in.args[1].value = entry->d_name.name;
482 return create_new_entry(fc, req, dir, entry, mode);
485 static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
486 struct nameidata *nd)
488 if (nd && (nd->flags & LOOKUP_OPEN)) {
489 int err = fuse_create_open(dir, entry, mode, nd);
492 /* Fall back on mknod */
494 return fuse_mknod(dir, entry, mode, 0);
497 static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode)
499 struct fuse_mkdir_in inarg;
500 struct fuse_conn *fc = get_fuse_conn(dir);
501 struct fuse_req *req = fuse_get_req(fc);
505 memset(&inarg, 0, sizeof(inarg));
507 req->in.h.opcode = FUSE_MKDIR;
509 req->in.args[0].size = sizeof(inarg);
510 req->in.args[0].value = &inarg;
511 req->in.args[1].size = entry->d_name.len + 1;
512 req->in.args[1].value = entry->d_name.name;
513 return create_new_entry(fc, req, dir, entry, S_IFDIR);
516 static int fuse_symlink(struct inode *dir, struct dentry *entry,
519 struct fuse_conn *fc = get_fuse_conn(dir);
520 unsigned len = strlen(link) + 1;
521 struct fuse_req *req = fuse_get_req(fc);
525 req->in.h.opcode = FUSE_SYMLINK;
527 req->in.args[0].size = entry->d_name.len + 1;
528 req->in.args[0].value = entry->d_name.name;
529 req->in.args[1].size = len;
530 req->in.args[1].value = link;
531 return create_new_entry(fc, req, dir, entry, S_IFLNK);
534 static int fuse_unlink(struct inode *dir, struct dentry *entry)
537 struct fuse_conn *fc = get_fuse_conn(dir);
538 struct fuse_req *req = fuse_get_req(fc);
542 req->in.h.opcode = FUSE_UNLINK;
543 req->in.h.nodeid = get_node_id(dir);
545 req->in.args[0].size = entry->d_name.len + 1;
546 req->in.args[0].value = entry->d_name.name;
547 request_send(fc, req);
548 err = req->out.h.error;
549 fuse_put_request(fc, req);
551 struct inode *inode = entry->d_inode;
553 /* Set nlink to zero so the inode can be cleared, if
554 the inode does have more links this will be
555 discovered at the next lookup/getattr */
557 fuse_invalidate_attr(inode);
558 fuse_invalidate_attr(dir);
559 fuse_invalidate_entry_cache(entry);
560 } else if (err == -EINTR)
561 fuse_invalidate_entry(entry);
565 static int fuse_rmdir(struct inode *dir, struct dentry *entry)
568 struct fuse_conn *fc = get_fuse_conn(dir);
569 struct fuse_req *req = fuse_get_req(fc);
573 req->in.h.opcode = FUSE_RMDIR;
574 req->in.h.nodeid = get_node_id(dir);
576 req->in.args[0].size = entry->d_name.len + 1;
577 req->in.args[0].value = entry->d_name.name;
578 request_send(fc, req);
579 err = req->out.h.error;
580 fuse_put_request(fc, req);
582 clear_nlink(entry->d_inode);
583 fuse_invalidate_attr(dir);
584 fuse_invalidate_entry_cache(entry);
585 } else if (err == -EINTR)
586 fuse_invalidate_entry(entry);
590 static int fuse_rename(struct inode *olddir, struct dentry *oldent,
591 struct inode *newdir, struct dentry *newent)
594 struct fuse_rename_in inarg;
595 struct fuse_conn *fc = get_fuse_conn(olddir);
596 struct fuse_req *req = fuse_get_req(fc);
600 memset(&inarg, 0, sizeof(inarg));
601 inarg.newdir = get_node_id(newdir);
602 req->in.h.opcode = FUSE_RENAME;
603 req->in.h.nodeid = get_node_id(olddir);
605 req->in.args[0].size = sizeof(inarg);
606 req->in.args[0].value = &inarg;
607 req->in.args[1].size = oldent->d_name.len + 1;
608 req->in.args[1].value = oldent->d_name.name;
609 req->in.args[2].size = newent->d_name.len + 1;
610 req->in.args[2].value = newent->d_name.name;
611 request_send(fc, req);
612 err = req->out.h.error;
613 fuse_put_request(fc, req);
615 fuse_invalidate_attr(olddir);
616 if (olddir != newdir)
617 fuse_invalidate_attr(newdir);
619 /* newent will end up negative */
621 fuse_invalidate_entry_cache(newent);
622 } else if (err == -EINTR) {
623 /* If request was interrupted, DEITY only knows if the
624 rename actually took place. If the invalidation
625 fails (e.g. some process has CWD under the renamed
626 directory), then there can be inconsistency between
627 the dcache and the real filesystem. Tough luck. */
628 fuse_invalidate_entry(oldent);
630 fuse_invalidate_entry(newent);
636 static int fuse_link(struct dentry *entry, struct inode *newdir,
637 struct dentry *newent)
640 struct fuse_link_in inarg;
641 struct inode *inode = entry->d_inode;
642 struct fuse_conn *fc = get_fuse_conn(inode);
643 struct fuse_req *req = fuse_get_req(fc);
647 memset(&inarg, 0, sizeof(inarg));
648 inarg.oldnodeid = get_node_id(inode);
649 req->in.h.opcode = FUSE_LINK;
651 req->in.args[0].size = sizeof(inarg);
652 req->in.args[0].value = &inarg;
653 req->in.args[1].size = newent->d_name.len + 1;
654 req->in.args[1].value = newent->d_name.name;
655 err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
656 /* Contrary to "normal" filesystems it can happen that link
657 makes two "logical" inodes point to the same "physical"
658 inode. We invalidate the attributes of the old one, so it
659 will reflect changes in the backing inode (link count,
662 if (!err || err == -EINTR)
663 fuse_invalidate_attr(inode);
667 int fuse_do_getattr(struct inode *inode)
670 struct fuse_attr_out arg;
671 struct fuse_conn *fc = get_fuse_conn(inode);
672 struct fuse_req *req = fuse_get_req(fc);
676 req->in.h.opcode = FUSE_GETATTR;
677 req->in.h.nodeid = get_node_id(inode);
678 req->out.numargs = 1;
679 req->out.args[0].size = sizeof(arg);
680 req->out.args[0].value = &arg;
681 request_send(fc, req);
682 err = req->out.h.error;
683 fuse_put_request(fc, req);
685 if ((inode->i_mode ^ arg.attr.mode) & S_IFMT) {
686 make_bad_inode(inode);
689 struct fuse_inode *fi = get_fuse_inode(inode);
690 fuse_change_attributes(inode, &arg.attr);
691 fi->i_time = time_to_jiffies(arg.attr_valid,
692 arg.attr_valid_nsec);
699 * Calling into a user-controlled filesystem gives the filesystem
700 * daemon ptrace-like capabilities over the requester process. This
701 * means, that the filesystem daemon is able to record the exact
702 * filesystem operations performed, and can also control the behavior
703 * of the requester process in otherwise impossible ways. For example
704 * it can delay the operation for arbitrary length of time allowing
705 * DoS against the requester.
707 * For this reason only those processes can call into the filesystem,
708 * for which the owner of the mount has ptrace privilege. This
709 * excludes processes started by other users, suid or sgid processes.
711 static int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
713 if (fc->flags & FUSE_ALLOW_OTHER)
716 if (task->euid == fc->user_id &&
717 task->suid == fc->user_id &&
718 task->uid == fc->user_id &&
719 task->egid == fc->group_id &&
720 task->sgid == fc->group_id &&
721 task->gid == fc->group_id)
728 * Check whether the inode attributes are still valid
730 * If the attribute validity timeout has expired, then fetch the fresh
731 * attributes with a 'getattr' request
733 * I'm not sure why cached attributes are never returned for the root
734 * inode, this is probably being too cautious.
736 static int fuse_revalidate(struct dentry *entry)
738 struct inode *inode = entry->d_inode;
739 struct fuse_inode *fi = get_fuse_inode(inode);
740 struct fuse_conn *fc = get_fuse_conn(inode);
742 if (!fuse_allow_task(fc, current))
744 if (get_node_id(inode) != FUSE_ROOT_ID &&
745 fi->i_time >= get_jiffies_64())
748 return fuse_do_getattr(inode);
751 static int fuse_access(struct inode *inode, int mask)
753 struct fuse_conn *fc = get_fuse_conn(inode);
754 struct fuse_req *req;
755 struct fuse_access_in inarg;
761 req = fuse_get_req(fc);
765 memset(&inarg, 0, sizeof(inarg));
767 req->in.h.opcode = FUSE_ACCESS;
768 req->in.h.nodeid = get_node_id(inode);
770 req->in.args[0].size = sizeof(inarg);
771 req->in.args[0].value = &inarg;
772 request_send(fc, req);
773 err = req->out.h.error;
774 fuse_put_request(fc, req);
775 if (err == -ENOSYS) {
783 * Check permission. The two basic access models of FUSE are:
785 * 1) Local access checking ('default_permissions' mount option) based
786 * on file mode. This is the plain old disk filesystem permission
789 * 2) "Remote" access checking, where server is responsible for
790 * checking permission in each inode operation. An exception to this
791 * is if ->permission() was invoked from sys_access() in which case an
792 * access request is sent. Execute permission is still checked
793 * locally based on file mode.
795 static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
797 struct fuse_conn *fc = get_fuse_conn(inode);
799 if (!fuse_allow_task(fc, current))
801 else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
802 int err = generic_permission(inode, mask, NULL);
804 /* If permission is denied, try to refresh file
805 attributes. This is also needed, because the root
806 node will at first have no permissions */
807 if (err == -EACCES) {
808 err = fuse_do_getattr(inode);
810 err = generic_permission(inode, mask, NULL);
813 /* Note: the opposite of the above test does not
814 exist. So if permissions are revoked this won't be
815 noticed immediately, only after the attribute
816 timeout has expired */
820 int mode = inode->i_mode;
821 if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
824 if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR)))
825 return fuse_access(inode, mask);
830 static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
831 void *dstbuf, filldir_t filldir)
833 while (nbytes >= FUSE_NAME_OFFSET) {
834 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
835 size_t reclen = FUSE_DIRENT_SIZE(dirent);
837 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
842 over = filldir(dstbuf, dirent->name, dirent->namelen,
843 file->f_pos, dirent->ino, dirent->type);
849 file->f_pos = dirent->off;
855 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
860 struct inode *inode = file->f_path.dentry->d_inode;
861 struct fuse_conn *fc = get_fuse_conn(inode);
862 struct fuse_req *req;
864 if (is_bad_inode(inode))
867 req = fuse_get_req(fc);
871 page = alloc_page(GFP_KERNEL);
873 fuse_put_request(fc, req);
877 req->pages[0] = page;
878 fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR);
879 request_send(fc, req);
880 nbytes = req->out.args[0].size;
881 err = req->out.h.error;
882 fuse_put_request(fc, req);
884 err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
888 fuse_invalidate_attr(inode); /* atime changed */
892 static char *read_link(struct dentry *dentry)
894 struct inode *inode = dentry->d_inode;
895 struct fuse_conn *fc = get_fuse_conn(inode);
896 struct fuse_req *req = fuse_get_req(fc);
900 return ERR_PTR(PTR_ERR(req));
902 link = (char *) __get_free_page(GFP_KERNEL);
904 link = ERR_PTR(-ENOMEM);
907 req->in.h.opcode = FUSE_READLINK;
908 req->in.h.nodeid = get_node_id(inode);
910 req->out.numargs = 1;
911 req->out.args[0].size = PAGE_SIZE - 1;
912 req->out.args[0].value = link;
913 request_send(fc, req);
914 if (req->out.h.error) {
915 free_page((unsigned long) link);
916 link = ERR_PTR(req->out.h.error);
918 link[req->out.args[0].size] = '\0';
920 fuse_put_request(fc, req);
921 fuse_invalidate_attr(inode); /* atime changed */
925 static void free_link(char *link)
928 free_page((unsigned long) link);
931 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
933 nd_set_link(nd, read_link(dentry));
937 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
939 free_link(nd_get_link(nd));
942 static int fuse_dir_open(struct inode *inode, struct file *file)
944 return fuse_open_common(inode, file, 1);
947 static int fuse_dir_release(struct inode *inode, struct file *file)
949 return fuse_release_common(inode, file, 1);
952 static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync)
954 /* nfsd can call this with no file */
955 return file ? fuse_fsync_common(file, de, datasync, 1) : 0;
958 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
960 unsigned ivalid = iattr->ia_valid;
962 if (ivalid & ATTR_MODE)
963 arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
964 if (ivalid & ATTR_UID)
965 arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
966 if (ivalid & ATTR_GID)
967 arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
968 if (ivalid & ATTR_SIZE)
969 arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
970 /* You can only _set_ these together (they may change by themselves) */
971 if ((ivalid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) {
972 arg->valid |= FATTR_ATIME | FATTR_MTIME;
973 arg->atime = iattr->ia_atime.tv_sec;
974 arg->mtime = iattr->ia_mtime.tv_sec;
976 if (ivalid & ATTR_FILE) {
977 struct fuse_file *ff = iattr->ia_file->private_data;
978 arg->valid |= FATTR_FH;
983 static void fuse_vmtruncate(struct inode *inode, loff_t offset)
985 struct fuse_conn *fc = get_fuse_conn(inode);
988 spin_lock(&fc->lock);
989 need_trunc = inode->i_size > offset;
990 i_size_write(inode, offset);
991 spin_unlock(&fc->lock);
994 struct address_space *mapping = inode->i_mapping;
995 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
996 truncate_inode_pages(mapping, offset);
1001 * Set attributes, and at the same time refresh them.
1003 * Truncation is slightly complicated, because the 'truncate' request
1004 * may fail, in which case we don't want to touch the mapping.
1005 * vmtruncate() doesn't allow for this case, so do the rlimit checking
1006 * and the actual truncation by hand.
1008 static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1010 struct inode *inode = entry->d_inode;
1011 struct fuse_conn *fc = get_fuse_conn(inode);
1012 struct fuse_inode *fi = get_fuse_inode(inode);
1013 struct fuse_req *req;
1014 struct fuse_setattr_in inarg;
1015 struct fuse_attr_out outarg;
1017 int is_truncate = 0;
1019 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
1020 err = inode_change_ok(inode, attr);
1025 if (attr->ia_valid & ATTR_SIZE) {
1026 unsigned long limit;
1028 if (IS_SWAPFILE(inode))
1030 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
1031 if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) {
1032 send_sig(SIGXFSZ, current, 0);
1037 req = fuse_get_req(fc);
1039 return PTR_ERR(req);
1041 memset(&inarg, 0, sizeof(inarg));
1042 iattr_to_fattr(attr, &inarg);
1043 req->in.h.opcode = FUSE_SETATTR;
1044 req->in.h.nodeid = get_node_id(inode);
1045 req->in.numargs = 1;
1046 req->in.args[0].size = sizeof(inarg);
1047 req->in.args[0].value = &inarg;
1048 req->out.numargs = 1;
1049 req->out.args[0].size = sizeof(outarg);
1050 req->out.args[0].value = &outarg;
1051 request_send(fc, req);
1052 err = req->out.h.error;
1053 fuse_put_request(fc, req);
1055 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1056 make_bad_inode(inode);
1060 fuse_vmtruncate(inode, outarg.attr.size);
1061 fuse_change_attributes(inode, &outarg.attr);
1062 fi->i_time = time_to_jiffies(outarg.attr_valid,
1063 outarg.attr_valid_nsec);
1065 } else if (err == -EINTR)
1066 fuse_invalidate_attr(inode);
1071 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
1074 struct inode *inode = entry->d_inode;
1075 int err = fuse_revalidate(entry);
1077 generic_fillattr(inode, stat);
1082 static int fuse_setxattr(struct dentry *entry, const char *name,
1083 const void *value, size_t size, int flags)
1085 struct inode *inode = entry->d_inode;
1086 struct fuse_conn *fc = get_fuse_conn(inode);
1087 struct fuse_req *req;
1088 struct fuse_setxattr_in inarg;
1091 if (fc->no_setxattr)
1094 req = fuse_get_req(fc);
1096 return PTR_ERR(req);
1098 memset(&inarg, 0, sizeof(inarg));
1100 inarg.flags = flags;
1101 req->in.h.opcode = FUSE_SETXATTR;
1102 req->in.h.nodeid = get_node_id(inode);
1103 req->in.numargs = 3;
1104 req->in.args[0].size = sizeof(inarg);
1105 req->in.args[0].value = &inarg;
1106 req->in.args[1].size = strlen(name) + 1;
1107 req->in.args[1].value = name;
1108 req->in.args[2].size = size;
1109 req->in.args[2].value = value;
1110 request_send(fc, req);
1111 err = req->out.h.error;
1112 fuse_put_request(fc, req);
1113 if (err == -ENOSYS) {
1114 fc->no_setxattr = 1;
1120 static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
1121 void *value, size_t size)
1123 struct inode *inode = entry->d_inode;
1124 struct fuse_conn *fc = get_fuse_conn(inode);
1125 struct fuse_req *req;
1126 struct fuse_getxattr_in inarg;
1127 struct fuse_getxattr_out outarg;
1130 if (fc->no_getxattr)
1133 req = fuse_get_req(fc);
1135 return PTR_ERR(req);
1137 memset(&inarg, 0, sizeof(inarg));
1139 req->in.h.opcode = FUSE_GETXATTR;
1140 req->in.h.nodeid = get_node_id(inode);
1141 req->in.numargs = 2;
1142 req->in.args[0].size = sizeof(inarg);
1143 req->in.args[0].value = &inarg;
1144 req->in.args[1].size = strlen(name) + 1;
1145 req->in.args[1].value = name;
1146 /* This is really two different operations rolled into one */
1147 req->out.numargs = 1;
1149 req->out.argvar = 1;
1150 req->out.args[0].size = size;
1151 req->out.args[0].value = value;
1153 req->out.args[0].size = sizeof(outarg);
1154 req->out.args[0].value = &outarg;
1156 request_send(fc, req);
1157 ret = req->out.h.error;
1159 ret = size ? req->out.args[0].size : outarg.size;
1161 if (ret == -ENOSYS) {
1162 fc->no_getxattr = 1;
1166 fuse_put_request(fc, req);
1170 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
1172 struct inode *inode = entry->d_inode;
1173 struct fuse_conn *fc = get_fuse_conn(inode);
1174 struct fuse_req *req;
1175 struct fuse_getxattr_in inarg;
1176 struct fuse_getxattr_out outarg;
1179 if (fc->no_listxattr)
1182 req = fuse_get_req(fc);
1184 return PTR_ERR(req);
1186 memset(&inarg, 0, sizeof(inarg));
1188 req->in.h.opcode = FUSE_LISTXATTR;
1189 req->in.h.nodeid = get_node_id(inode);
1190 req->in.numargs = 1;
1191 req->in.args[0].size = sizeof(inarg);
1192 req->in.args[0].value = &inarg;
1193 /* This is really two different operations rolled into one */
1194 req->out.numargs = 1;
1196 req->out.argvar = 1;
1197 req->out.args[0].size = size;
1198 req->out.args[0].value = list;
1200 req->out.args[0].size = sizeof(outarg);
1201 req->out.args[0].value = &outarg;
1203 request_send(fc, req);
1204 ret = req->out.h.error;
1206 ret = size ? req->out.args[0].size : outarg.size;
1208 if (ret == -ENOSYS) {
1209 fc->no_listxattr = 1;
1213 fuse_put_request(fc, req);
1217 static int fuse_removexattr(struct dentry *entry, const char *name)
1219 struct inode *inode = entry->d_inode;
1220 struct fuse_conn *fc = get_fuse_conn(inode);
1221 struct fuse_req *req;
1224 if (fc->no_removexattr)
1227 req = fuse_get_req(fc);
1229 return PTR_ERR(req);
1231 req->in.h.opcode = FUSE_REMOVEXATTR;
1232 req->in.h.nodeid = get_node_id(inode);
1233 req->in.numargs = 1;
1234 req->in.args[0].size = strlen(name) + 1;
1235 req->in.args[0].value = name;
1236 request_send(fc, req);
1237 err = req->out.h.error;
1238 fuse_put_request(fc, req);
1239 if (err == -ENOSYS) {
1240 fc->no_removexattr = 1;
1246 static const struct inode_operations fuse_dir_inode_operations = {
1247 .lookup = fuse_lookup,
1248 .mkdir = fuse_mkdir,
1249 .symlink = fuse_symlink,
1250 .unlink = fuse_unlink,
1251 .rmdir = fuse_rmdir,
1252 .rename = fuse_rename,
1254 .setattr = fuse_setattr,
1255 .create = fuse_create,
1256 .mknod = fuse_mknod,
1257 .permission = fuse_permission,
1258 .getattr = fuse_getattr,
1259 .setxattr = fuse_setxattr,
1260 .getxattr = fuse_getxattr,
1261 .listxattr = fuse_listxattr,
1262 .removexattr = fuse_removexattr,
1265 static const struct file_operations fuse_dir_operations = {
1266 .llseek = generic_file_llseek,
1267 .read = generic_read_dir,
1268 .readdir = fuse_readdir,
1269 .open = fuse_dir_open,
1270 .release = fuse_dir_release,
1271 .fsync = fuse_dir_fsync,
1274 static const struct inode_operations fuse_common_inode_operations = {
1275 .setattr = fuse_setattr,
1276 .permission = fuse_permission,
1277 .getattr = fuse_getattr,
1278 .setxattr = fuse_setxattr,
1279 .getxattr = fuse_getxattr,
1280 .listxattr = fuse_listxattr,
1281 .removexattr = fuse_removexattr,
1284 static const struct inode_operations fuse_symlink_inode_operations = {
1285 .setattr = fuse_setattr,
1286 .follow_link = fuse_follow_link,
1287 .put_link = fuse_put_link,
1288 .readlink = generic_readlink,
1289 .getattr = fuse_getattr,
1290 .setxattr = fuse_setxattr,
1291 .getxattr = fuse_getxattr,
1292 .listxattr = fuse_listxattr,
1293 .removexattr = fuse_removexattr,
1296 void fuse_init_common(struct inode *inode)
1298 inode->i_op = &fuse_common_inode_operations;
1301 void fuse_init_dir(struct inode *inode)
1303 inode->i_op = &fuse_dir_inode_operations;
1304 inode->i_fop = &fuse_dir_operations;
1307 void fuse_init_symlink(struct inode *inode)
1309 inode->i_op = &fuse_symlink_inode_operations;