2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2005 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 struct file_operations fuse_direct_io_file_operations;
17 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
19 struct fuse_conn *fc = get_fuse_conn(inode);
21 struct fuse_open_in inarg;
22 struct fuse_open_out outarg;
25 /* Restarting the syscall is not allowed if O_CREAT and O_EXCL
26 are both set, because creation will fail on the restart */
27 int excl = (file->f_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL);
29 err = generic_file_open(inode, file);
33 /* If opening the root node, no lookup has been performed on
34 it, so the attributes must be refreshed */
35 if (get_node_id(inode) == FUSE_ROOT_ID) {
36 int err = fuse_do_getattr(inode);
42 req = fuse_get_request_nonint(fc);
44 req = fuse_get_request(fc);
46 return excl ? -EINTR : -ERESTARTSYS;
49 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
53 ff->release_req = fuse_request_alloc();
54 if (!ff->release_req) {
59 memset(&inarg, 0, sizeof(inarg));
60 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
61 req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
62 req->in.h.nodeid = get_node_id(inode);
65 req->in.args[0].size = sizeof(inarg);
66 req->in.args[0].value = &inarg;
68 req->out.args[0].size = sizeof(outarg);
69 req->out.args[0].value = &outarg;
71 request_send_nonint(fc, req);
73 request_send(fc, req);
74 err = req->out.h.error;
76 fuse_request_free(ff->release_req);
79 if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO))
80 file->f_op = &fuse_direct_io_file_operations;
81 if (!(outarg.open_flags & FOPEN_KEEP_CACHE))
82 invalidate_inode_pages(inode->i_mapping);
84 file->private_data = ff;
88 fuse_put_request(fc, req);
92 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
94 struct fuse_conn *fc = get_fuse_conn(inode);
95 struct fuse_file *ff = file->private_data;
96 struct fuse_req *req = ff->release_req;
97 struct fuse_release_in *inarg = &req->misc.release_in;
100 inarg->flags = file->f_flags & ~O_EXCL;
101 req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
102 req->in.h.nodeid = get_node_id(inode);
105 req->in.args[0].size = sizeof(struct fuse_release_in);
106 req->in.args[0].value = inarg;
107 request_send_background(fc, req);
110 /* Return value is ignored by VFS */
114 static int fuse_open(struct inode *inode, struct file *file)
116 return fuse_open_common(inode, file, 0);
119 static int fuse_release(struct inode *inode, struct file *file)
121 return fuse_release_common(inode, file, 0);
124 static int fuse_flush(struct file *file)
126 struct inode *inode = file->f_dentry->d_inode;
127 struct fuse_conn *fc = get_fuse_conn(inode);
128 struct fuse_file *ff = file->private_data;
129 struct fuse_req *req;
130 struct fuse_flush_in inarg;
136 req = fuse_get_request_nonint(fc);
140 memset(&inarg, 0, sizeof(inarg));
142 req->in.h.opcode = FUSE_FLUSH;
143 req->in.h.nodeid = get_node_id(inode);
147 req->in.args[0].size = sizeof(inarg);
148 req->in.args[0].value = &inarg;
149 request_send_nonint(fc, req);
150 err = req->out.h.error;
151 fuse_put_request(fc, req);
152 if (err == -ENOSYS) {
159 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
161 struct inode *inode = de->d_inode;
162 struct fuse_conn *fc = get_fuse_conn(inode);
163 struct fuse_file *ff = file->private_data;
164 struct fuse_req *req;
165 struct fuse_fsync_in inarg;
171 req = fuse_get_request(fc);
175 memset(&inarg, 0, sizeof(inarg));
177 inarg.fsync_flags = datasync ? 1 : 0;
178 req->in.h.opcode = FUSE_FSYNC;
179 req->in.h.nodeid = get_node_id(inode);
183 req->in.args[0].size = sizeof(inarg);
184 req->in.args[0].value = &inarg;
185 request_send(fc, req);
186 err = req->out.h.error;
187 fuse_put_request(fc, req);
188 if (err == -ENOSYS) {
195 size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
196 struct inode *inode, loff_t pos, size_t count,
199 struct fuse_conn *fc = get_fuse_conn(inode);
200 struct fuse_file *ff = file->private_data;
201 struct fuse_read_in inarg;
203 memset(&inarg, 0, sizeof(struct fuse_read_in));
207 req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ;
208 req->in.h.nodeid = get_node_id(inode);
212 req->in.args[0].size = sizeof(struct fuse_read_in);
213 req->in.args[0].value = &inarg;
214 req->out.argpages = 1;
216 req->out.numargs = 1;
217 req->out.args[0].size = count;
218 request_send_nonint(fc, req);
219 return req->out.args[0].size;
222 static inline size_t fuse_send_read(struct fuse_req *req, struct file *file,
223 struct inode *inode, loff_t pos,
226 return fuse_send_read_common(req, file, inode, pos, count, 0);
229 static int fuse_readpage(struct file *file, struct page *page)
231 struct inode *inode = page->mapping->host;
232 struct fuse_conn *fc = get_fuse_conn(inode);
233 loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT;
234 struct fuse_req *req = fuse_get_request_nonint(fc);
239 req->out.page_zeroing = 1;
241 req->pages[0] = page;
242 fuse_send_read(req, file, inode, pos, PAGE_CACHE_SIZE);
243 err = req->out.h.error;
244 fuse_put_request(fc, req);
246 SetPageUptodate(page);
252 static int fuse_send_readpages(struct fuse_req *req, struct file *file,
255 loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
256 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
258 req->out.page_zeroing = 1;
259 fuse_send_read(req, file, inode, pos, count);
260 for (i = 0; i < req->num_pages; i++) {
261 struct page *page = req->pages[i];
262 if (!req->out.h.error)
263 SetPageUptodate(page);
266 return req->out.h.error;
269 struct fuse_readpages_data {
270 struct fuse_req *req;
275 static int fuse_readpages_fill(void *_data, struct page *page)
277 struct fuse_readpages_data *data = _data;
278 struct fuse_req *req = data->req;
279 struct inode *inode = data->inode;
280 struct fuse_conn *fc = get_fuse_conn(inode);
282 if (req->num_pages &&
283 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
284 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
285 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
286 int err = fuse_send_readpages(req, data->file, inode);
291 fuse_reset_request(req);
293 req->pages[req->num_pages] = page;
298 static int fuse_readpages(struct file *file, struct address_space *mapping,
299 struct list_head *pages, unsigned nr_pages)
301 struct inode *inode = mapping->host;
302 struct fuse_conn *fc = get_fuse_conn(inode);
303 struct fuse_readpages_data data;
307 data.req = fuse_get_request_nonint(fc);
311 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
312 if (!err && data.req->num_pages)
313 err = fuse_send_readpages(data.req, file, inode);
314 fuse_put_request(fc, data.req);
318 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
319 struct inode *inode, loff_t pos, size_t count)
321 struct fuse_conn *fc = get_fuse_conn(inode);
322 struct fuse_file *ff = file->private_data;
323 struct fuse_write_in inarg;
324 struct fuse_write_out outarg;
326 memset(&inarg, 0, sizeof(struct fuse_write_in));
330 req->in.h.opcode = FUSE_WRITE;
331 req->in.h.nodeid = get_node_id(inode);
334 req->in.argpages = 1;
336 req->in.args[0].size = sizeof(struct fuse_write_in);
337 req->in.args[0].value = &inarg;
338 req->in.args[1].size = count;
339 req->out.numargs = 1;
340 req->out.args[0].size = sizeof(struct fuse_write_out);
341 req->out.args[0].value = &outarg;
342 request_send_nonint(fc, req);
346 static int fuse_prepare_write(struct file *file, struct page *page,
347 unsigned offset, unsigned to)
353 static int fuse_commit_write(struct file *file, struct page *page,
354 unsigned offset, unsigned to)
358 unsigned count = to - offset;
359 struct inode *inode = page->mapping->host;
360 struct fuse_conn *fc = get_fuse_conn(inode);
361 loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;
362 struct fuse_req *req = fuse_get_request_nonint(fc);
367 req->pages[0] = page;
368 req->page_offset = offset;
369 nres = fuse_send_write(req, file, inode, pos, count);
370 err = req->out.h.error;
371 fuse_put_request(fc, req);
372 if (!err && nres != count)
376 if (pos > i_size_read(inode))
377 i_size_write(inode, pos);
379 if (offset == 0 && to == PAGE_CACHE_SIZE) {
380 clear_page_dirty(page);
381 SetPageUptodate(page);
383 } else if (err == -EINTR || err == -EIO)
384 fuse_invalidate_attr(inode);
388 static void fuse_release_user_pages(struct fuse_req *req, int write)
392 for (i = 0; i < req->num_pages; i++) {
393 struct page *page = req->pages[i];
395 set_page_dirty_lock(page);
400 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
401 unsigned nbytes, int write)
403 unsigned long user_addr = (unsigned long) buf;
404 unsigned offset = user_addr & ~PAGE_MASK;
407 /* This doesn't work with nfsd */
411 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
412 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
413 npages = min(npages, FUSE_MAX_PAGES_PER_REQ);
414 down_read(¤t->mm->mmap_sem);
415 npages = get_user_pages(current, current->mm, user_addr, npages, write,
416 0, req->pages, NULL);
417 up_read(¤t->mm->mmap_sem);
421 req->num_pages = npages;
422 req->page_offset = offset;
426 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
427 size_t count, loff_t *ppos, int write)
429 struct inode *inode = file->f_dentry->d_inode;
430 struct fuse_conn *fc = get_fuse_conn(inode);
431 size_t nmax = write ? fc->max_write : fc->max_read;
434 struct fuse_req *req = fuse_get_request(fc);
441 size_t nbytes = min(count, nmax);
442 int err = fuse_get_user_pages(req, buf, nbytes, !write);
447 tmp = (req->num_pages << PAGE_SHIFT) - req->page_offset;
448 nbytes = min(nbytes, tmp);
450 nres = fuse_send_write(req, file, inode, pos, nbytes);
452 nres = fuse_send_read(req, file, inode, pos, nbytes);
453 fuse_release_user_pages(req, !write);
454 if (req->out.h.error) {
456 res = req->out.h.error;
458 } else if (nres > nbytes) {
469 fuse_reset_request(req);
471 fuse_put_request(fc, req);
473 if (write && pos > i_size_read(inode))
474 i_size_write(inode, pos);
476 } else if (write && (res == -EINTR || res == -EIO))
477 fuse_invalidate_attr(inode);
482 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
483 size_t count, loff_t *ppos)
485 return fuse_direct_io(file, buf, count, ppos, 0);
488 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
489 size_t count, loff_t *ppos)
491 struct inode *inode = file->f_dentry->d_inode;
493 /* Don't allow parallel writes to the same file */
495 res = fuse_direct_io(file, buf, count, ppos, 1);
500 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
502 if ((vma->vm_flags & VM_SHARED)) {
503 if ((vma->vm_flags & VM_WRITE))
506 vma->vm_flags &= ~VM_MAYWRITE;
508 return generic_file_mmap(file, vma);
511 static int fuse_set_page_dirty(struct page *page)
513 printk("fuse_set_page_dirty: should not happen\n");
518 static struct file_operations fuse_file_operations = {
519 .llseek = generic_file_llseek,
520 .read = generic_file_read,
521 .write = generic_file_write,
522 .mmap = fuse_file_mmap,
525 .release = fuse_release,
527 .sendfile = generic_file_sendfile,
530 static struct file_operations fuse_direct_io_file_operations = {
531 .llseek = generic_file_llseek,
532 .read = fuse_direct_read,
533 .write = fuse_direct_write,
536 .release = fuse_release,
538 /* no mmap and sendfile */
541 static struct address_space_operations fuse_file_aops = {
542 .readpage = fuse_readpage,
543 .prepare_write = fuse_prepare_write,
544 .commit_write = fuse_commit_write,
545 .readpages = fuse_readpages,
546 .set_page_dirty = fuse_set_page_dirty,
549 void fuse_init_file_inode(struct inode *inode)
551 inode->i_fop = &fuse_file_operations;
552 inode->i_data.a_ops = &fuse_file_aops;