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 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
162 struct inode *inode = de->d_inode;
163 struct fuse_conn *fc = get_fuse_conn(inode);
164 struct fuse_file *ff = file->private_data;
165 struct fuse_req *req;
166 struct fuse_fsync_in inarg;
169 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
172 req = fuse_get_request(fc);
176 memset(&inarg, 0, sizeof(inarg));
178 inarg.fsync_flags = datasync ? 1 : 0;
179 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
180 req->in.h.nodeid = get_node_id(inode);
184 req->in.args[0].size = sizeof(inarg);
185 req->in.args[0].value = &inarg;
186 request_send(fc, req);
187 err = req->out.h.error;
188 fuse_put_request(fc, req);
189 if (err == -ENOSYS) {
199 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
201 return fuse_fsync_common(file, de, datasync, 0);
204 size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
205 struct inode *inode, loff_t pos, size_t count,
208 struct fuse_conn *fc = get_fuse_conn(inode);
209 struct fuse_file *ff = file->private_data;
210 struct fuse_read_in inarg;
212 memset(&inarg, 0, sizeof(struct fuse_read_in));
216 req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ;
217 req->in.h.nodeid = get_node_id(inode);
221 req->in.args[0].size = sizeof(struct fuse_read_in);
222 req->in.args[0].value = &inarg;
223 req->out.argpages = 1;
225 req->out.numargs = 1;
226 req->out.args[0].size = count;
227 request_send_nonint(fc, req);
228 return req->out.args[0].size;
231 static inline size_t fuse_send_read(struct fuse_req *req, struct file *file,
232 struct inode *inode, loff_t pos,
235 return fuse_send_read_common(req, file, inode, pos, count, 0);
238 static int fuse_readpage(struct file *file, struct page *page)
240 struct inode *inode = page->mapping->host;
241 struct fuse_conn *fc = get_fuse_conn(inode);
242 loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT;
243 struct fuse_req *req = fuse_get_request_nonint(fc);
248 req->out.page_zeroing = 1;
250 req->pages[0] = page;
251 fuse_send_read(req, file, inode, pos, PAGE_CACHE_SIZE);
252 err = req->out.h.error;
253 fuse_put_request(fc, req);
255 SetPageUptodate(page);
256 fuse_invalidate_attr(inode); /* atime changed */
262 static int fuse_send_readpages(struct fuse_req *req, struct file *file,
265 loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
266 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
268 req->out.page_zeroing = 1;
269 fuse_send_read(req, file, inode, pos, count);
270 for (i = 0; i < req->num_pages; i++) {
271 struct page *page = req->pages[i];
272 if (!req->out.h.error)
273 SetPageUptodate(page);
276 return req->out.h.error;
279 struct fuse_readpages_data {
280 struct fuse_req *req;
285 static int fuse_readpages_fill(void *_data, struct page *page)
287 struct fuse_readpages_data *data = _data;
288 struct fuse_req *req = data->req;
289 struct inode *inode = data->inode;
290 struct fuse_conn *fc = get_fuse_conn(inode);
292 if (req->num_pages &&
293 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
294 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
295 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
296 int err = fuse_send_readpages(req, data->file, inode);
301 fuse_reset_request(req);
303 req->pages[req->num_pages] = page;
308 static int fuse_readpages(struct file *file, struct address_space *mapping,
309 struct list_head *pages, unsigned nr_pages)
311 struct inode *inode = mapping->host;
312 struct fuse_conn *fc = get_fuse_conn(inode);
313 struct fuse_readpages_data data;
317 data.req = fuse_get_request_nonint(fc);
321 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
322 if (!err && data.req->num_pages)
323 err = fuse_send_readpages(data.req, file, inode);
324 fuse_put_request(fc, data.req);
325 fuse_invalidate_attr(inode); /* atime changed */
329 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
330 struct inode *inode, loff_t pos, size_t count)
332 struct fuse_conn *fc = get_fuse_conn(inode);
333 struct fuse_file *ff = file->private_data;
334 struct fuse_write_in inarg;
335 struct fuse_write_out outarg;
337 memset(&inarg, 0, sizeof(struct fuse_write_in));
341 req->in.h.opcode = FUSE_WRITE;
342 req->in.h.nodeid = get_node_id(inode);
345 req->in.argpages = 1;
347 req->in.args[0].size = sizeof(struct fuse_write_in);
348 req->in.args[0].value = &inarg;
349 req->in.args[1].size = count;
350 req->out.numargs = 1;
351 req->out.args[0].size = sizeof(struct fuse_write_out);
352 req->out.args[0].value = &outarg;
353 request_send_nonint(fc, req);
357 static int fuse_prepare_write(struct file *file, struct page *page,
358 unsigned offset, unsigned to)
364 static int fuse_commit_write(struct file *file, struct page *page,
365 unsigned offset, unsigned to)
369 unsigned count = to - offset;
370 struct inode *inode = page->mapping->host;
371 struct fuse_conn *fc = get_fuse_conn(inode);
372 loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;
373 struct fuse_req *req = fuse_get_request_nonint(fc);
378 req->pages[0] = page;
379 req->page_offset = offset;
380 nres = fuse_send_write(req, file, inode, pos, count);
381 err = req->out.h.error;
382 fuse_put_request(fc, req);
383 if (!err && nres != count)
387 if (pos > i_size_read(inode))
388 i_size_write(inode, pos);
390 if (offset == 0 && to == PAGE_CACHE_SIZE) {
391 clear_page_dirty(page);
392 SetPageUptodate(page);
395 fuse_invalidate_attr(inode);
399 static void fuse_release_user_pages(struct fuse_req *req, int write)
403 for (i = 0; i < req->num_pages; i++) {
404 struct page *page = req->pages[i];
406 set_page_dirty_lock(page);
411 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
412 unsigned nbytes, int write)
414 unsigned long user_addr = (unsigned long) buf;
415 unsigned offset = user_addr & ~PAGE_MASK;
418 /* This doesn't work with nfsd */
422 nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
423 npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
424 npages = min(npages, FUSE_MAX_PAGES_PER_REQ);
425 down_read(¤t->mm->mmap_sem);
426 npages = get_user_pages(current, current->mm, user_addr, npages, write,
427 0, req->pages, NULL);
428 up_read(¤t->mm->mmap_sem);
432 req->num_pages = npages;
433 req->page_offset = offset;
437 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
438 size_t count, loff_t *ppos, int write)
440 struct inode *inode = file->f_dentry->d_inode;
441 struct fuse_conn *fc = get_fuse_conn(inode);
442 size_t nmax = write ? fc->max_write : fc->max_read;
445 struct fuse_req *req = fuse_get_request(fc);
452 size_t nbytes = min(count, nmax);
453 int err = fuse_get_user_pages(req, buf, nbytes, !write);
458 tmp = (req->num_pages << PAGE_SHIFT) - req->page_offset;
459 nbytes = min(nbytes, tmp);
461 nres = fuse_send_write(req, file, inode, pos, nbytes);
463 nres = fuse_send_read(req, file, inode, pos, nbytes);
464 fuse_release_user_pages(req, !write);
465 if (req->out.h.error) {
467 res = req->out.h.error;
469 } else if (nres > nbytes) {
480 fuse_reset_request(req);
482 fuse_put_request(fc, req);
484 if (write && pos > i_size_read(inode))
485 i_size_write(inode, pos);
488 fuse_invalidate_attr(inode);
493 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
494 size_t count, loff_t *ppos)
496 return fuse_direct_io(file, buf, count, ppos, 0);
499 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
500 size_t count, loff_t *ppos)
502 struct inode *inode = file->f_dentry->d_inode;
504 /* Don't allow parallel writes to the same file */
506 res = fuse_direct_io(file, buf, count, ppos, 1);
511 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
513 if ((vma->vm_flags & VM_SHARED)) {
514 if ((vma->vm_flags & VM_WRITE))
517 vma->vm_flags &= ~VM_MAYWRITE;
519 return generic_file_mmap(file, vma);
522 static int fuse_set_page_dirty(struct page *page)
524 printk("fuse_set_page_dirty: should not happen\n");
529 static struct file_operations fuse_file_operations = {
530 .llseek = generic_file_llseek,
531 .read = generic_file_read,
532 .write = generic_file_write,
533 .mmap = fuse_file_mmap,
536 .release = fuse_release,
538 .sendfile = generic_file_sendfile,
541 static struct file_operations fuse_direct_io_file_operations = {
542 .llseek = generic_file_llseek,
543 .read = fuse_direct_read,
544 .write = fuse_direct_write,
547 .release = fuse_release,
549 /* no mmap and sendfile */
552 static struct address_space_operations fuse_file_aops = {
553 .readpage = fuse_readpage,
554 .prepare_write = fuse_prepare_write,
555 .commit_write = fuse_commit_write,
556 .readpages = fuse_readpages,
557 .set_page_dirty = fuse_set_page_dirty,
560 void fuse_init_file_inode(struct inode *inode)
562 inode->i_fop = &fuse_file_operations;
563 inode->i_data.a_ops = &fuse_file_aops;