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 int fuse_open(struct inode *inode, struct file *file)
17 struct fuse_conn *fc = get_fuse_conn(inode);
19 struct fuse_open_in inarg;
20 struct fuse_open_out outarg;
23 /* Restarting the syscall is not allowed if O_CREAT and O_EXCL
24 are both set, because creation will fail on the restart */
25 int excl = (file->f_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL);
27 err = generic_file_open(inode, file);
31 /* If opening the root node, no lookup has been performed on
32 it, so the attributes must be refreshed */
33 if (get_node_id(inode) == FUSE_ROOT_ID) {
34 int err = fuse_do_getattr(inode);
40 req = fuse_get_request_nonint(fc);
42 req = fuse_get_request(fc);
44 return excl ? -EINTR : -ERESTARTSYS;
47 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
51 ff->release_req = fuse_request_alloc();
52 if (!ff->release_req) {
57 memset(&inarg, 0, sizeof(inarg));
58 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
59 req->in.h.opcode = FUSE_OPEN;
60 req->in.h.nodeid = get_node_id(inode);
63 req->in.args[0].size = sizeof(inarg);
64 req->in.args[0].value = &inarg;
66 req->out.args[0].size = sizeof(outarg);
67 req->out.args[0].value = &outarg;
69 request_send_nonint(fc, req);
71 request_send(fc, req);
72 err = req->out.h.error;
73 if (!err && !(fc->flags & FUSE_KERNEL_CACHE))
74 invalidate_inode_pages(inode->i_mapping);
76 fuse_request_free(ff->release_req);
80 file->private_data = ff;
84 fuse_put_request(fc, req);
88 static int fuse_release(struct inode *inode, struct file *file)
90 struct fuse_conn *fc = get_fuse_conn(inode);
91 struct fuse_file *ff = file->private_data;
92 struct fuse_req *req = ff->release_req;
93 struct fuse_release_in *inarg = &req->misc.release_in;
96 inarg->flags = file->f_flags & ~O_EXCL;
97 req->in.h.opcode = FUSE_RELEASE;
98 req->in.h.nodeid = get_node_id(inode);
101 req->in.args[0].size = sizeof(struct fuse_release_in);
102 req->in.args[0].value = inarg;
103 request_send_background(fc, req);
106 /* Return value is ignored by VFS */
110 static int fuse_flush(struct file *file)
112 struct inode *inode = file->f_dentry->d_inode;
113 struct fuse_conn *fc = get_fuse_conn(inode);
114 struct fuse_file *ff = file->private_data;
115 struct fuse_req *req;
116 struct fuse_flush_in inarg;
122 req = fuse_get_request_nonint(fc);
126 memset(&inarg, 0, sizeof(inarg));
128 req->in.h.opcode = FUSE_FLUSH;
129 req->in.h.nodeid = get_node_id(inode);
133 req->in.args[0].size = sizeof(inarg);
134 req->in.args[0].value = &inarg;
135 request_send_nonint(fc, req);
136 err = req->out.h.error;
137 fuse_put_request(fc, req);
138 if (err == -ENOSYS) {
145 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
147 struct inode *inode = de->d_inode;
148 struct fuse_conn *fc = get_fuse_conn(inode);
149 struct fuse_file *ff = file->private_data;
150 struct fuse_req *req;
151 struct fuse_fsync_in inarg;
157 req = fuse_get_request(fc);
161 memset(&inarg, 0, sizeof(inarg));
163 inarg.fsync_flags = datasync ? 1 : 0;
164 req->in.h.opcode = FUSE_FSYNC;
165 req->in.h.nodeid = get_node_id(inode);
169 req->in.args[0].size = sizeof(inarg);
170 req->in.args[0].value = &inarg;
171 request_send(fc, req);
172 err = req->out.h.error;
173 fuse_put_request(fc, req);
174 if (err == -ENOSYS) {
181 static ssize_t fuse_send_read(struct fuse_req *req, struct file *file,
182 struct inode *inode, loff_t pos, size_t count)
184 struct fuse_conn *fc = get_fuse_conn(inode);
185 struct fuse_file *ff = file->private_data;
186 struct fuse_read_in inarg;
188 memset(&inarg, 0, sizeof(struct fuse_read_in));
192 req->in.h.opcode = FUSE_READ;
193 req->in.h.nodeid = get_node_id(inode);
197 req->in.args[0].size = sizeof(struct fuse_read_in);
198 req->in.args[0].value = &inarg;
199 req->out.argpages = 1;
201 req->out.numargs = 1;
202 req->out.args[0].size = count;
203 request_send_nonint(fc, req);
204 return req->out.args[0].size;
207 static int fuse_readpage(struct file *file, struct page *page)
209 struct inode *inode = page->mapping->host;
210 struct fuse_conn *fc = get_fuse_conn(inode);
211 loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT;
212 struct fuse_req *req = fuse_get_request_nonint(fc);
217 req->out.page_zeroing = 1;
219 req->pages[0] = page;
220 fuse_send_read(req, file, inode, pos, PAGE_CACHE_SIZE);
221 err = req->out.h.error;
222 fuse_put_request(fc, req);
224 SetPageUptodate(page);
230 static int fuse_send_readpages(struct fuse_req *req, struct file *file,
233 loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
234 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
236 req->out.page_zeroing = 1;
237 fuse_send_read(req, file, inode, pos, count);
238 for (i = 0; i < req->num_pages; i++) {
239 struct page *page = req->pages[i];
240 if (!req->out.h.error)
241 SetPageUptodate(page);
244 return req->out.h.error;
247 struct fuse_readpages_data {
248 struct fuse_req *req;
253 static int fuse_readpages_fill(void *_data, struct page *page)
255 struct fuse_readpages_data *data = _data;
256 struct fuse_req *req = data->req;
257 struct inode *inode = data->inode;
258 struct fuse_conn *fc = get_fuse_conn(inode);
260 if (req->num_pages &&
261 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
262 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
263 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
264 int err = fuse_send_readpages(req, data->file, inode);
269 fuse_reset_request(req);
271 req->pages[req->num_pages] = page;
276 static int fuse_readpages(struct file *file, struct address_space *mapping,
277 struct list_head *pages, unsigned nr_pages)
279 struct inode *inode = mapping->host;
280 struct fuse_conn *fc = get_fuse_conn(inode);
281 struct fuse_readpages_data data;
285 data.req = fuse_get_request_nonint(fc);
289 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
290 if (!err && data.req->num_pages)
291 err = fuse_send_readpages(data.req, file, inode);
292 fuse_put_request(fc, data.req);
296 static ssize_t fuse_send_write(struct fuse_req *req, struct file *file,
297 struct inode *inode, loff_t pos, size_t count)
299 struct fuse_conn *fc = get_fuse_conn(inode);
300 struct fuse_file *ff = file->private_data;
301 struct fuse_write_in inarg;
302 struct fuse_write_out outarg;
304 memset(&inarg, 0, sizeof(struct fuse_write_in));
308 req->in.h.opcode = FUSE_WRITE;
309 req->in.h.nodeid = get_node_id(inode);
312 req->in.argpages = 1;
314 req->in.args[0].size = sizeof(struct fuse_write_in);
315 req->in.args[0].value = &inarg;
316 req->in.args[1].size = count;
317 req->out.numargs = 1;
318 req->out.args[0].size = sizeof(struct fuse_write_out);
319 req->out.args[0].value = &outarg;
320 request_send_nonint(fc, req);
324 static int fuse_prepare_write(struct file *file, struct page *page,
325 unsigned offset, unsigned to)
331 static int fuse_commit_write(struct file *file, struct page *page,
332 unsigned offset, unsigned to)
336 unsigned count = to - offset;
337 struct inode *inode = page->mapping->host;
338 struct fuse_conn *fc = get_fuse_conn(inode);
339 loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;
340 struct fuse_req *req = fuse_get_request_nonint(fc);
345 req->pages[0] = page;
346 req->page_offset = offset;
347 nres = fuse_send_write(req, file, inode, pos, count);
348 err = req->out.h.error;
349 fuse_put_request(fc, req);
350 if (!err && nres != count)
354 if (pos > i_size_read(inode))
355 i_size_write(inode, pos);
357 if (offset == 0 && to == PAGE_CACHE_SIZE) {
358 clear_page_dirty(page);
359 SetPageUptodate(page);
361 } else if (err == -EINTR || err == -EIO)
362 fuse_invalidate_attr(inode);
366 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
368 if ((vma->vm_flags & VM_SHARED)) {
369 if ((vma->vm_flags & VM_WRITE))
372 vma->vm_flags &= ~VM_MAYWRITE;
374 return generic_file_mmap(file, vma);
377 static int fuse_set_page_dirty(struct page *page)
379 printk("fuse_set_page_dirty: should not happen\n");
384 static struct file_operations fuse_file_operations = {
385 .llseek = generic_file_llseek,
386 .read = generic_file_read,
387 .write = generic_file_write,
388 .mmap = fuse_file_mmap,
391 .release = fuse_release,
393 .sendfile = generic_file_sendfile,
396 static struct address_space_operations fuse_file_aops = {
397 .readpage = fuse_readpage,
398 .prepare_write = fuse_prepare_write,
399 .commit_write = fuse_commit_write,
400 .readpages = fuse_readpages,
401 .set_page_dirty = fuse_set_page_dirty,
404 void fuse_init_file_inode(struct inode *inode)
406 inode->i_fop = &fuse_file_operations;
407 inode->i_data.a_ops = &fuse_file_aops;