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/slab.h>
13 #include <linux/kernel.h>
15 static const struct file_operations fuse_direct_io_file_operations;
17 static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
18 struct fuse_open_out *outargp)
20 struct fuse_conn *fc = get_fuse_conn(inode);
21 struct fuse_open_in inarg;
25 req = fuse_get_req(fc);
29 memset(&inarg, 0, sizeof(inarg));
30 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
31 req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
32 req->in.h.nodeid = get_node_id(inode);
34 req->in.args[0].size = sizeof(inarg);
35 req->in.args[0].value = &inarg;
37 req->out.args[0].size = sizeof(*outargp);
38 req->out.args[0].value = outargp;
39 request_send(fc, req);
40 err = req->out.h.error;
41 fuse_put_request(fc, req);
46 struct fuse_file *fuse_file_alloc(void)
49 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
51 ff->release_req = fuse_request_alloc();
52 if (!ff->release_req) {
60 void fuse_file_free(struct fuse_file *ff)
62 fuse_request_free(ff->release_req);
66 void fuse_finish_open(struct inode *inode, struct file *file,
67 struct fuse_file *ff, struct fuse_open_out *outarg)
69 if (outarg->open_flags & FOPEN_DIRECT_IO)
70 file->f_op = &fuse_direct_io_file_operations;
71 if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
72 invalidate_inode_pages(inode->i_mapping);
74 file->private_data = ff;
77 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
79 struct fuse_open_out outarg;
83 /* VFS checks this, but only _after_ ->open() */
84 if (file->f_flags & O_DIRECT)
87 err = generic_file_open(inode, file);
91 /* If opening the root node, no lookup has been performed on
92 it, so the attributes must be refreshed */
93 if (get_node_id(inode) == FUSE_ROOT_ID) {
94 err = fuse_do_getattr(inode);
99 ff = fuse_file_alloc();
103 err = fuse_send_open(inode, file, isdir, &outarg);
108 outarg.open_flags &= ~FOPEN_DIRECT_IO;
109 fuse_finish_open(inode, file, ff, &outarg);
115 struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags,
118 struct fuse_req *req = ff->release_req;
119 struct fuse_release_in *inarg = &req->misc.release_in;
122 inarg->flags = flags;
123 req->in.h.opcode = opcode;
124 req->in.h.nodeid = nodeid;
126 req->in.args[0].size = sizeof(struct fuse_release_in);
127 req->in.args[0].value = inarg;
133 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
135 struct fuse_file *ff = file->private_data;
137 struct fuse_conn *fc = get_fuse_conn(inode);
138 struct fuse_req *req;
140 req = fuse_release_fill(ff, get_node_id(inode), file->f_flags,
141 isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
143 /* Hold vfsmount and dentry until release is finished */
144 req->vfsmount = mntget(file->f_vfsmnt);
145 req->dentry = dget(file->f_dentry);
146 request_send_background(fc, req);
149 /* Return value is ignored by VFS */
153 static int fuse_open(struct inode *inode, struct file *file)
155 return fuse_open_common(inode, file, 0);
158 static int fuse_release(struct inode *inode, struct file *file)
160 return fuse_release_common(inode, file, 0);
163 static int fuse_flush(struct file *file, fl_owner_t id)
165 struct inode *inode = file->f_dentry->d_inode;
166 struct fuse_conn *fc = get_fuse_conn(inode);
167 struct fuse_file *ff = file->private_data;
168 struct fuse_req *req;
169 struct fuse_flush_in inarg;
172 if (is_bad_inode(inode))
178 req = fuse_get_req(fc);
182 memset(&inarg, 0, sizeof(inarg));
184 req->in.h.opcode = FUSE_FLUSH;
185 req->in.h.nodeid = get_node_id(inode);
187 req->in.args[0].size = sizeof(inarg);
188 req->in.args[0].value = &inarg;
189 request_send(fc, req);
190 err = req->out.h.error;
191 fuse_put_request(fc, req);
192 if (err == -ENOSYS) {
199 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
202 struct inode *inode = de->d_inode;
203 struct fuse_conn *fc = get_fuse_conn(inode);
204 struct fuse_file *ff = file->private_data;
205 struct fuse_req *req;
206 struct fuse_fsync_in inarg;
209 if (is_bad_inode(inode))
212 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
215 req = fuse_get_req(fc);
219 memset(&inarg, 0, sizeof(inarg));
221 inarg.fsync_flags = datasync ? 1 : 0;
222 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
223 req->in.h.nodeid = get_node_id(inode);
225 req->in.args[0].size = sizeof(inarg);
226 req->in.args[0].value = &inarg;
227 request_send(fc, req);
228 err = req->out.h.error;
229 fuse_put_request(fc, req);
230 if (err == -ENOSYS) {
240 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
242 return fuse_fsync_common(file, de, datasync, 0);
245 void fuse_read_fill(struct fuse_req *req, struct file *file,
246 struct inode *inode, loff_t pos, size_t count, int opcode)
248 struct fuse_file *ff = file->private_data;
249 struct fuse_read_in *inarg = &req->misc.read_in;
254 req->in.h.opcode = opcode;
255 req->in.h.nodeid = get_node_id(inode);
257 req->in.args[0].size = sizeof(struct fuse_read_in);
258 req->in.args[0].value = inarg;
259 req->out.argpages = 1;
261 req->out.numargs = 1;
262 req->out.args[0].size = count;
265 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
266 struct inode *inode, loff_t pos, size_t count)
268 struct fuse_conn *fc = get_fuse_conn(inode);
269 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
270 request_send(fc, req);
271 return req->out.args[0].size;
274 static int fuse_readpage(struct file *file, struct page *page)
276 struct inode *inode = page->mapping->host;
277 struct fuse_conn *fc = get_fuse_conn(inode);
278 struct fuse_req *req;
282 if (is_bad_inode(inode))
285 req = fuse_get_req(fc);
290 req->out.page_zeroing = 1;
292 req->pages[0] = page;
293 fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
294 err = req->out.h.error;
295 fuse_put_request(fc, req);
297 SetPageUptodate(page);
298 fuse_invalidate_attr(inode); /* atime changed */
304 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
308 fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
310 for (i = 0; i < req->num_pages; i++) {
311 struct page *page = req->pages[i];
312 if (!req->out.h.error)
313 SetPageUptodate(page);
318 fuse_put_request(fc, req);
321 static void fuse_send_readpages(struct fuse_req *req, struct file *file,
324 struct fuse_conn *fc = get_fuse_conn(inode);
325 loff_t pos = page_offset(req->pages[0]);
326 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
327 req->out.page_zeroing = 1;
328 fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
329 if (fc->async_read) {
332 req->end = fuse_readpages_end;
333 request_send_background(fc, req);
335 request_send(fc, req);
336 fuse_readpages_end(fc, req);
340 struct fuse_readpages_data {
341 struct fuse_req *req;
346 static int fuse_readpages_fill(void *_data, struct page *page)
348 struct fuse_readpages_data *data = _data;
349 struct fuse_req *req = data->req;
350 struct inode *inode = data->inode;
351 struct fuse_conn *fc = get_fuse_conn(inode);
353 if (req->num_pages &&
354 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
355 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
356 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
357 fuse_send_readpages(req, data->file, inode);
358 data->req = req = fuse_get_req(fc);
364 req->pages[req->num_pages] = page;
369 static int fuse_readpages(struct file *file, struct address_space *mapping,
370 struct list_head *pages, unsigned nr_pages)
372 struct inode *inode = mapping->host;
373 struct fuse_conn *fc = get_fuse_conn(inode);
374 struct fuse_readpages_data data;
377 if (is_bad_inode(inode))
382 data.req = fuse_get_req(fc);
383 if (IS_ERR(data.req))
384 return PTR_ERR(data.req);
386 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
388 if (data.req->num_pages)
389 fuse_send_readpages(data.req, file, inode);
391 fuse_put_request(fc, data.req);
396 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
397 struct inode *inode, loff_t pos, size_t count)
399 struct fuse_conn *fc = get_fuse_conn(inode);
400 struct fuse_file *ff = file->private_data;
401 struct fuse_write_in inarg;
402 struct fuse_write_out outarg;
404 memset(&inarg, 0, sizeof(struct fuse_write_in));
408 req->in.h.opcode = FUSE_WRITE;
409 req->in.h.nodeid = get_node_id(inode);
410 req->in.argpages = 1;
412 req->in.args[0].size = sizeof(struct fuse_write_in);
413 req->in.args[0].value = &inarg;
414 req->in.args[1].size = count;
415 req->out.numargs = 1;
416 req->out.args[0].size = sizeof(struct fuse_write_out);
417 req->out.args[0].value = &outarg;
418 request_send(fc, req);
422 static int fuse_prepare_write(struct file *file, struct page *page,
423 unsigned offset, unsigned to)
429 static int fuse_commit_write(struct file *file, struct page *page,
430 unsigned offset, unsigned to)
434 unsigned count = to - offset;
435 struct inode *inode = page->mapping->host;
436 struct fuse_conn *fc = get_fuse_conn(inode);
437 loff_t pos = page_offset(page) + offset;
438 struct fuse_req *req;
440 if (is_bad_inode(inode))
443 req = fuse_get_req(fc);
448 req->pages[0] = page;
449 req->page_offset = offset;
450 nres = fuse_send_write(req, file, inode, pos, count);
451 err = req->out.h.error;
452 fuse_put_request(fc, req);
453 if (!err && nres != count)
457 if (pos > i_size_read(inode))
458 i_size_write(inode, pos);
460 if (offset == 0 && to == PAGE_CACHE_SIZE) {
461 clear_page_dirty(page);
462 SetPageUptodate(page);
465 fuse_invalidate_attr(inode);
469 static void fuse_release_user_pages(struct fuse_req *req, int write)
473 for (i = 0; i < req->num_pages; i++) {
474 struct page *page = req->pages[i];
476 set_page_dirty_lock(page);
481 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
482 unsigned nbytes, int write)
484 unsigned long user_addr = (unsigned long) buf;
485 unsigned offset = user_addr & ~PAGE_MASK;
488 /* This doesn't work with nfsd */
492 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
493 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
494 npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
495 down_read(¤t->mm->mmap_sem);
496 npages = get_user_pages(current, current->mm, user_addr, npages, write,
497 0, req->pages, NULL);
498 up_read(¤t->mm->mmap_sem);
502 req->num_pages = npages;
503 req->page_offset = offset;
507 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
508 size_t count, loff_t *ppos, int write)
510 struct inode *inode = file->f_dentry->d_inode;
511 struct fuse_conn *fc = get_fuse_conn(inode);
512 size_t nmax = write ? fc->max_write : fc->max_read;
515 struct fuse_req *req;
517 if (is_bad_inode(inode))
520 req = fuse_get_req(fc);
526 size_t nbytes = min(count, nmax);
527 int err = fuse_get_user_pages(req, buf, nbytes, !write);
532 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
533 nbytes = min(count, nbytes);
535 nres = fuse_send_write(req, file, inode, pos, nbytes);
537 nres = fuse_send_read(req, file, inode, pos, nbytes);
538 fuse_release_user_pages(req, !write);
539 if (req->out.h.error) {
541 res = req->out.h.error;
543 } else if (nres > nbytes) {
554 fuse_put_request(fc, req);
555 req = fuse_get_req(fc);
560 fuse_put_request(fc, req);
562 if (write && pos > i_size_read(inode))
563 i_size_write(inode, pos);
566 fuse_invalidate_attr(inode);
571 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
572 size_t count, loff_t *ppos)
574 return fuse_direct_io(file, buf, count, ppos, 0);
577 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
578 size_t count, loff_t *ppos)
580 struct inode *inode = file->f_dentry->d_inode;
582 /* Don't allow parallel writes to the same file */
583 mutex_lock(&inode->i_mutex);
584 res = fuse_direct_io(file, buf, count, ppos, 1);
585 mutex_unlock(&inode->i_mutex);
589 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
591 if ((vma->vm_flags & VM_SHARED)) {
592 if ((vma->vm_flags & VM_WRITE))
595 vma->vm_flags &= ~VM_MAYWRITE;
597 return generic_file_mmap(file, vma);
600 static int fuse_set_page_dirty(struct page *page)
602 printk("fuse_set_page_dirty: should not happen\n");
607 static const struct file_operations fuse_file_operations = {
608 .llseek = generic_file_llseek,
609 .read = generic_file_read,
610 .write = generic_file_write,
611 .mmap = fuse_file_mmap,
614 .release = fuse_release,
616 .sendfile = generic_file_sendfile,
619 static const struct file_operations fuse_direct_io_file_operations = {
620 .llseek = generic_file_llseek,
621 .read = fuse_direct_read,
622 .write = fuse_direct_write,
625 .release = fuse_release,
627 /* no mmap and sendfile */
630 static struct address_space_operations fuse_file_aops = {
631 .readpage = fuse_readpage,
632 .prepare_write = fuse_prepare_write,
633 .commit_write = fuse_commit_write,
634 .readpages = fuse_readpages,
635 .set_page_dirty = fuse_set_page_dirty,
638 void fuse_init_file_inode(struct inode *inode)
640 inode->i_fop = &fuse_file_operations;
641 inode->i_data.a_ops = &fuse_file_aops;