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 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_request(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);
35 req->in.args[0].size = sizeof(inarg);
36 req->in.args[0].value = &inarg;
38 req->out.args[0].size = sizeof(*outargp);
39 req->out.args[0].value = outargp;
40 request_send(fc, req);
41 err = req->out.h.error;
42 fuse_put_request(fc, req);
47 struct fuse_file *fuse_file_alloc(void)
50 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
52 ff->release_req = fuse_request_alloc();
53 if (!ff->release_req) {
61 void fuse_file_free(struct fuse_file *ff)
63 fuse_request_free(ff->release_req);
67 void fuse_finish_open(struct inode *inode, struct file *file,
68 struct fuse_file *ff, struct fuse_open_out *outarg)
70 if (outarg->open_flags & FOPEN_DIRECT_IO)
71 file->f_op = &fuse_direct_io_file_operations;
72 if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
73 invalidate_inode_pages(inode->i_mapping);
75 file->private_data = ff;
78 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
80 struct fuse_open_out outarg;
84 /* VFS checks this, but only _after_ ->open() */
85 if (file->f_flags & O_DIRECT)
88 err = generic_file_open(inode, file);
92 /* If opening the root node, no lookup has been performed on
93 it, so the attributes must be refreshed */
94 if (get_node_id(inode) == FUSE_ROOT_ID) {
95 err = fuse_do_getattr(inode);
100 ff = fuse_file_alloc();
104 err = fuse_send_open(inode, file, isdir, &outarg);
109 outarg.open_flags &= ~FOPEN_DIRECT_IO;
110 fuse_finish_open(inode, file, ff, &outarg);
116 /* Special case for failed iget in CREATE */
117 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
119 u64 nodeid = req->in.h.nodeid;
120 fuse_reset_request(req);
121 fuse_send_forget(fc, req, nodeid, 1);
124 void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
125 u64 nodeid, struct inode *inode, int flags, int isdir)
127 struct fuse_req * req = ff->release_req;
128 struct fuse_release_in *inarg = &req->misc.release_in;
131 inarg->flags = flags;
132 req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
133 req->in.h.nodeid = nodeid;
136 req->in.args[0].size = sizeof(struct fuse_release_in);
137 req->in.args[0].value = inarg;
138 request_send_background(fc, req);
140 req->end = fuse_release_end;
144 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
146 struct fuse_file *ff = file->private_data;
148 struct fuse_conn *fc = get_fuse_conn(inode);
149 u64 nodeid = get_node_id(inode);
150 fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
153 /* Return value is ignored by VFS */
157 static int fuse_open(struct inode *inode, struct file *file)
159 return fuse_open_common(inode, file, 0);
162 static int fuse_release(struct inode *inode, struct file *file)
164 return fuse_release_common(inode, file, 0);
167 static int fuse_flush(struct file *file)
169 struct inode *inode = file->f_dentry->d_inode;
170 struct fuse_conn *fc = get_fuse_conn(inode);
171 struct fuse_file *ff = file->private_data;
172 struct fuse_req *req;
173 struct fuse_flush_in inarg;
176 if (is_bad_inode(inode))
182 req = fuse_get_request(fc);
186 memset(&inarg, 0, sizeof(inarg));
188 req->in.h.opcode = FUSE_FLUSH;
189 req->in.h.nodeid = get_node_id(inode);
193 req->in.args[0].size = sizeof(inarg);
194 req->in.args[0].value = &inarg;
195 request_send(fc, req);
196 err = req->out.h.error;
197 fuse_put_request(fc, req);
198 if (err == -ENOSYS) {
205 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
208 struct inode *inode = de->d_inode;
209 struct fuse_conn *fc = get_fuse_conn(inode);
210 struct fuse_file *ff = file->private_data;
211 struct fuse_req *req;
212 struct fuse_fsync_in inarg;
215 if (is_bad_inode(inode))
218 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
221 req = fuse_get_request(fc);
225 memset(&inarg, 0, sizeof(inarg));
227 inarg.fsync_flags = datasync ? 1 : 0;
228 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
229 req->in.h.nodeid = get_node_id(inode);
233 req->in.args[0].size = sizeof(inarg);
234 req->in.args[0].value = &inarg;
235 request_send(fc, req);
236 err = req->out.h.error;
237 fuse_put_request(fc, req);
238 if (err == -ENOSYS) {
248 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
250 return fuse_fsync_common(file, de, datasync, 0);
253 size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
254 struct inode *inode, loff_t pos, size_t count,
257 struct fuse_conn *fc = get_fuse_conn(inode);
258 struct fuse_file *ff = file->private_data;
259 struct fuse_read_in inarg;
261 memset(&inarg, 0, sizeof(struct fuse_read_in));
265 req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ;
266 req->in.h.nodeid = get_node_id(inode);
270 req->in.args[0].size = sizeof(struct fuse_read_in);
271 req->in.args[0].value = &inarg;
272 req->out.argpages = 1;
274 req->out.numargs = 1;
275 req->out.args[0].size = count;
276 request_send(fc, req);
277 return req->out.args[0].size;
280 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
281 struct inode *inode, loff_t pos, size_t count)
283 return fuse_send_read_common(req, file, inode, pos, count, 0);
286 static int fuse_readpage(struct file *file, struct page *page)
288 struct inode *inode = page->mapping->host;
289 struct fuse_conn *fc = get_fuse_conn(inode);
290 struct fuse_req *req;
294 if (is_bad_inode(inode))
298 req = fuse_get_request(fc);
302 req->out.page_zeroing = 1;
304 req->pages[0] = page;
305 fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
306 err = req->out.h.error;
307 fuse_put_request(fc, req);
309 SetPageUptodate(page);
310 fuse_invalidate_attr(inode); /* atime changed */
316 static int fuse_send_readpages(struct fuse_req *req, struct file *file,
319 loff_t pos = page_offset(req->pages[0]);
320 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
322 req->out.page_zeroing = 1;
323 fuse_send_read(req, file, inode, pos, count);
324 for (i = 0; i < req->num_pages; i++) {
325 struct page *page = req->pages[i];
326 if (!req->out.h.error)
327 SetPageUptodate(page);
330 return req->out.h.error;
333 struct fuse_readpages_data {
334 struct fuse_req *req;
339 static int fuse_readpages_fill(void *_data, struct page *page)
341 struct fuse_readpages_data *data = _data;
342 struct fuse_req *req = data->req;
343 struct inode *inode = data->inode;
344 struct fuse_conn *fc = get_fuse_conn(inode);
346 if (req->num_pages &&
347 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
348 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
349 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
350 int err = fuse_send_readpages(req, data->file, inode);
355 fuse_reset_request(req);
357 req->pages[req->num_pages] = page;
362 static int fuse_readpages(struct file *file, struct address_space *mapping,
363 struct list_head *pages, unsigned nr_pages)
365 struct inode *inode = mapping->host;
366 struct fuse_conn *fc = get_fuse_conn(inode);
367 struct fuse_readpages_data data;
370 if (is_bad_inode(inode))
375 data.req = fuse_get_request(fc);
379 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
380 if (!err && data.req->num_pages)
381 err = fuse_send_readpages(data.req, file, inode);
382 fuse_put_request(fc, data.req);
383 fuse_invalidate_attr(inode); /* atime changed */
387 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
388 struct inode *inode, loff_t pos, size_t count)
390 struct fuse_conn *fc = get_fuse_conn(inode);
391 struct fuse_file *ff = file->private_data;
392 struct fuse_write_in inarg;
393 struct fuse_write_out outarg;
395 memset(&inarg, 0, sizeof(struct fuse_write_in));
399 req->in.h.opcode = FUSE_WRITE;
400 req->in.h.nodeid = get_node_id(inode);
403 req->in.argpages = 1;
405 req->in.args[0].size = sizeof(struct fuse_write_in);
406 req->in.args[0].value = &inarg;
407 req->in.args[1].size = count;
408 req->out.numargs = 1;
409 req->out.args[0].size = sizeof(struct fuse_write_out);
410 req->out.args[0].value = &outarg;
411 request_send(fc, req);
415 static int fuse_prepare_write(struct file *file, struct page *page,
416 unsigned offset, unsigned to)
422 static int fuse_commit_write(struct file *file, struct page *page,
423 unsigned offset, unsigned to)
427 unsigned count = to - offset;
428 struct inode *inode = page->mapping->host;
429 struct fuse_conn *fc = get_fuse_conn(inode);
430 loff_t pos = page_offset(page) + offset;
431 struct fuse_req *req;
433 if (is_bad_inode(inode))
436 req = fuse_get_request(fc);
441 req->pages[0] = page;
442 req->page_offset = offset;
443 nres = fuse_send_write(req, file, inode, pos, count);
444 err = req->out.h.error;
445 fuse_put_request(fc, req);
446 if (!err && nres != count)
450 if (pos > i_size_read(inode))
451 i_size_write(inode, pos);
453 if (offset == 0 && to == PAGE_CACHE_SIZE) {
454 clear_page_dirty(page);
455 SetPageUptodate(page);
458 fuse_invalidate_attr(inode);
462 static void fuse_release_user_pages(struct fuse_req *req, int write)
466 for (i = 0; i < req->num_pages; i++) {
467 struct page *page = req->pages[i];
469 set_page_dirty_lock(page);
474 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
475 unsigned nbytes, int write)
477 unsigned long user_addr = (unsigned long) buf;
478 unsigned offset = user_addr & ~PAGE_MASK;
481 /* This doesn't work with nfsd */
485 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
486 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
487 npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
488 down_read(¤t->mm->mmap_sem);
489 npages = get_user_pages(current, current->mm, user_addr, npages, write,
490 0, req->pages, NULL);
491 up_read(¤t->mm->mmap_sem);
495 req->num_pages = npages;
496 req->page_offset = offset;
500 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
501 size_t count, loff_t *ppos, int write)
503 struct inode *inode = file->f_dentry->d_inode;
504 struct fuse_conn *fc = get_fuse_conn(inode);
505 size_t nmax = write ? fc->max_write : fc->max_read;
508 struct fuse_req *req;
510 if (is_bad_inode(inode))
513 req = fuse_get_request(fc);
519 size_t nbytes = min(count, nmax);
520 int err = fuse_get_user_pages(req, buf, nbytes, !write);
525 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
526 nbytes = min(count, nbytes);
528 nres = fuse_send_write(req, file, inode, pos, nbytes);
530 nres = fuse_send_read(req, file, inode, pos, nbytes);
531 fuse_release_user_pages(req, !write);
532 if (req->out.h.error) {
534 res = req->out.h.error;
536 } else if (nres > nbytes) {
547 fuse_reset_request(req);
549 fuse_put_request(fc, req);
551 if (write && pos > i_size_read(inode))
552 i_size_write(inode, pos);
555 fuse_invalidate_attr(inode);
560 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
561 size_t count, loff_t *ppos)
563 return fuse_direct_io(file, buf, count, ppos, 0);
566 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
567 size_t count, loff_t *ppos)
569 struct inode *inode = file->f_dentry->d_inode;
571 /* Don't allow parallel writes to the same file */
572 mutex_lock(&inode->i_mutex);
573 res = fuse_direct_io(file, buf, count, ppos, 1);
574 mutex_unlock(&inode->i_mutex);
578 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
580 if ((vma->vm_flags & VM_SHARED)) {
581 if ((vma->vm_flags & VM_WRITE))
584 vma->vm_flags &= ~VM_MAYWRITE;
586 return generic_file_mmap(file, vma);
589 static int fuse_set_page_dirty(struct page *page)
591 printk("fuse_set_page_dirty: should not happen\n");
596 static struct file_operations fuse_file_operations = {
597 .llseek = generic_file_llseek,
598 .read = generic_file_read,
599 .write = generic_file_write,
600 .mmap = fuse_file_mmap,
603 .release = fuse_release,
605 .sendfile = generic_file_sendfile,
608 static struct file_operations fuse_direct_io_file_operations = {
609 .llseek = generic_file_llseek,
610 .read = fuse_direct_read,
611 .write = fuse_direct_write,
614 .release = fuse_release,
616 /* no mmap and sendfile */
619 static struct address_space_operations fuse_file_aops = {
620 .readpage = fuse_readpage,
621 .prepare_write = fuse_prepare_write,
622 .commit_write = fuse_commit_write,
623 .readpages = fuse_readpages,
624 .set_page_dirty = fuse_set_page_dirty,
627 void fuse_init_file_inode(struct inode *inode)
629 inode->i_fop = &fuse_file_operations;
630 inode->i_data.a_ops = &fuse_file_aops;