2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 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>
14 #include <linux/sched.h>
15 #include <linux/module.h>
16 #include <linux/compat.h>
17 #include <linux/swap.h>
18 #include <linux/aio.h>
19 #include <linux/falloc.h>
21 static const struct file_operations fuse_direct_io_file_operations;
23 static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
24 int opcode, struct fuse_open_out *outargp)
26 struct fuse_open_in inarg;
30 req = fuse_get_req_nopages(fc);
34 memset(&inarg, 0, sizeof(inarg));
35 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
36 if (!fc->atomic_o_trunc)
37 inarg.flags &= ~O_TRUNC;
38 req->in.h.opcode = opcode;
39 req->in.h.nodeid = nodeid;
41 req->in.args[0].size = sizeof(inarg);
42 req->in.args[0].value = &inarg;
44 req->out.args[0].size = sizeof(*outargp);
45 req->out.args[0].value = outargp;
46 fuse_request_send(fc, req);
47 err = req->out.h.error;
48 fuse_put_request(fc, req);
53 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
57 ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
62 ff->reserved_req = fuse_request_alloc(0);
63 if (unlikely(!ff->reserved_req)) {
68 INIT_LIST_HEAD(&ff->write_entry);
69 atomic_set(&ff->count, 0);
70 RB_CLEAR_NODE(&ff->polled_node);
71 init_waitqueue_head(&ff->poll_wait);
75 spin_unlock(&fc->lock);
80 void fuse_file_free(struct fuse_file *ff)
82 fuse_request_free(ff->reserved_req);
86 struct fuse_file *fuse_file_get(struct fuse_file *ff)
88 atomic_inc(&ff->count);
92 static void fuse_release_async(struct work_struct *work)
98 req = container_of(work, struct fuse_req, misc.release.work);
99 path = req->misc.release.path;
100 fc = get_fuse_conn(path.dentry->d_inode);
102 fuse_put_request(fc, req);
106 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
108 if (fc->destroy_req) {
110 * If this is a fuseblk mount, then it's possible that
111 * releasing the path will result in releasing the
112 * super block and sending the DESTROY request. If
113 * the server is single threaded, this would hang.
114 * For this reason do the path_put() in a separate
117 atomic_inc(&req->count);
118 INIT_WORK(&req->misc.release.work, fuse_release_async);
119 schedule_work(&req->misc.release.work);
121 path_put(&req->misc.release.path);
125 static void fuse_file_put(struct fuse_file *ff, bool sync)
127 if (atomic_dec_and_test(&ff->count)) {
128 struct fuse_req *req = ff->reserved_req;
130 if (ff->fc->no_open) {
132 * Drop the release request when client does not
136 path_put(&req->misc.release.path);
137 fuse_put_request(ff->fc, req);
140 fuse_request_send(ff->fc, req);
141 path_put(&req->misc.release.path);
142 fuse_put_request(ff->fc, req);
144 req->end = fuse_release_end;
146 fuse_request_send_background(ff->fc, req);
152 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
155 struct fuse_file *ff;
156 int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
158 ff = fuse_file_alloc(fc);
163 ff->open_flags = FOPEN_KEEP_CACHE; /* Default for no-open */
164 if (!fc->no_open || isdir) {
165 struct fuse_open_out outarg;
168 err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
171 ff->open_flags = outarg.open_flags;
173 } else if (err != -ENOSYS || isdir) {
182 ff->open_flags &= ~FOPEN_DIRECT_IO;
185 file->private_data = fuse_file_get(ff);
189 EXPORT_SYMBOL_GPL(fuse_do_open);
191 void fuse_finish_open(struct inode *inode, struct file *file)
193 struct fuse_file *ff = file->private_data;
194 struct fuse_conn *fc = get_fuse_conn(inode);
196 if (ff->open_flags & FOPEN_DIRECT_IO)
197 file->f_op = &fuse_direct_io_file_operations;
198 if (!(ff->open_flags & FOPEN_KEEP_CACHE))
199 invalidate_inode_pages2(inode->i_mapping);
200 if (ff->open_flags & FOPEN_NONSEEKABLE)
201 nonseekable_open(inode, file);
202 if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
203 struct fuse_inode *fi = get_fuse_inode(inode);
205 spin_lock(&fc->lock);
206 fi->attr_version = ++fc->attr_version;
207 i_size_write(inode, 0);
208 spin_unlock(&fc->lock);
209 fuse_invalidate_attr(inode);
213 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
215 struct fuse_conn *fc = get_fuse_conn(inode);
218 err = generic_file_open(inode, file);
222 err = fuse_do_open(fc, get_node_id(inode), file, isdir);
226 fuse_finish_open(inode, file);
231 static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
233 struct fuse_conn *fc = ff->fc;
234 struct fuse_req *req = ff->reserved_req;
235 struct fuse_release_in *inarg = &req->misc.release.in;
237 spin_lock(&fc->lock);
238 list_del(&ff->write_entry);
239 if (!RB_EMPTY_NODE(&ff->polled_node))
240 rb_erase(&ff->polled_node, &fc->polled_files);
241 spin_unlock(&fc->lock);
243 wake_up_interruptible_all(&ff->poll_wait);
246 inarg->flags = flags;
247 req->in.h.opcode = opcode;
248 req->in.h.nodeid = ff->nodeid;
250 req->in.args[0].size = sizeof(struct fuse_release_in);
251 req->in.args[0].value = inarg;
254 void fuse_release_common(struct file *file, int opcode)
256 struct fuse_file *ff;
257 struct fuse_req *req;
259 ff = file->private_data;
263 req = ff->reserved_req;
264 fuse_prepare_release(ff, file->f_flags, opcode);
267 struct fuse_release_in *inarg = &req->misc.release.in;
268 inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
269 inarg->lock_owner = fuse_lock_owner_id(ff->fc,
272 /* Hold vfsmount and dentry until release is finished */
273 path_get(&file->f_path);
274 req->misc.release.path = file->f_path;
277 * Normally this will send the RELEASE request, however if
278 * some asynchronous READ or WRITE requests are outstanding,
279 * the sending will be delayed.
281 * Make the release synchronous if this is a fuseblk mount,
282 * synchronous RELEASE is allowed (and desirable) in this case
283 * because the server can be trusted not to screw up.
285 fuse_file_put(ff, ff->fc->destroy_req != NULL);
288 static int fuse_open(struct inode *inode, struct file *file)
290 return fuse_open_common(inode, file, false);
293 static int fuse_release(struct inode *inode, struct file *file)
295 fuse_release_common(file, FUSE_RELEASE);
297 /* return value is ignored by VFS */
301 void fuse_sync_release(struct fuse_file *ff, int flags)
303 WARN_ON(atomic_read(&ff->count) > 1);
304 fuse_prepare_release(ff, flags, FUSE_RELEASE);
305 ff->reserved_req->force = 1;
306 ff->reserved_req->background = 0;
307 fuse_request_send(ff->fc, ff->reserved_req);
308 fuse_put_request(ff->fc, ff->reserved_req);
311 EXPORT_SYMBOL_GPL(fuse_sync_release);
314 * Scramble the ID space with XTEA, so that the value of the files_struct
315 * pointer is not exposed to userspace.
317 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
319 u32 *k = fc->scramble_key;
320 u64 v = (unsigned long) id;
326 for (i = 0; i < 32; i++) {
327 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
329 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
332 return (u64) v0 + ((u64) v1 << 32);
336 * Check if page is under writeback
338 * This is currently done by walking the list of writepage requests
339 * for the inode, which can be pretty inefficient.
341 static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
343 struct fuse_conn *fc = get_fuse_conn(inode);
344 struct fuse_inode *fi = get_fuse_inode(inode);
345 struct fuse_req *req;
348 spin_lock(&fc->lock);
349 list_for_each_entry(req, &fi->writepages, writepages_entry) {
352 BUG_ON(req->inode != inode);
353 curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
354 if (curr_index <= index &&
355 index < curr_index + req->num_pages) {
360 spin_unlock(&fc->lock);
366 * Wait for page writeback to be completed.
368 * Since fuse doesn't rely on the VM writeback tracking, this has to
369 * use some other means.
371 static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
373 struct fuse_inode *fi = get_fuse_inode(inode);
375 wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
379 static int fuse_flush(struct file *file, fl_owner_t id)
381 struct inode *inode = file_inode(file);
382 struct fuse_conn *fc = get_fuse_conn(inode);
383 struct fuse_file *ff = file->private_data;
384 struct fuse_req *req;
385 struct fuse_flush_in inarg;
388 if (is_bad_inode(inode))
394 req = fuse_get_req_nofail_nopages(fc, file);
395 memset(&inarg, 0, sizeof(inarg));
397 inarg.lock_owner = fuse_lock_owner_id(fc, id);
398 req->in.h.opcode = FUSE_FLUSH;
399 req->in.h.nodeid = get_node_id(inode);
401 req->in.args[0].size = sizeof(inarg);
402 req->in.args[0].value = &inarg;
404 fuse_request_send(fc, req);
405 err = req->out.h.error;
406 fuse_put_request(fc, req);
407 if (err == -ENOSYS) {
415 * Wait for all pending writepages on the inode to finish.
417 * This is currently done by blocking further writes with FUSE_NOWRITE
418 * and waiting for all sent writes to complete.
420 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
421 * could conflict with truncation.
423 static void fuse_sync_writes(struct inode *inode)
425 fuse_set_nowrite(inode);
426 fuse_release_nowrite(inode);
429 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
430 int datasync, int isdir)
432 struct inode *inode = file->f_mapping->host;
433 struct fuse_conn *fc = get_fuse_conn(inode);
434 struct fuse_file *ff = file->private_data;
435 struct fuse_req *req;
436 struct fuse_fsync_in inarg;
439 if (is_bad_inode(inode))
442 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
446 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
449 mutex_lock(&inode->i_mutex);
452 * Start writeback against all dirty pages of the inode, then
453 * wait for all outstanding writes, before sending the FSYNC
456 err = write_inode_now(inode, 0);
460 fuse_sync_writes(inode);
462 req = fuse_get_req_nopages(fc);
468 memset(&inarg, 0, sizeof(inarg));
470 inarg.fsync_flags = datasync ? 1 : 0;
471 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
472 req->in.h.nodeid = get_node_id(inode);
474 req->in.args[0].size = sizeof(inarg);
475 req->in.args[0].value = &inarg;
476 fuse_request_send(fc, req);
477 err = req->out.h.error;
478 fuse_put_request(fc, req);
479 if (err == -ENOSYS) {
487 mutex_unlock(&inode->i_mutex);
491 static int fuse_fsync(struct file *file, loff_t start, loff_t end,
494 return fuse_fsync_common(file, start, end, datasync, 0);
497 void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
498 size_t count, int opcode)
500 struct fuse_read_in *inarg = &req->misc.read.in;
501 struct fuse_file *ff = file->private_data;
506 inarg->flags = file->f_flags;
507 req->in.h.opcode = opcode;
508 req->in.h.nodeid = ff->nodeid;
510 req->in.args[0].size = sizeof(struct fuse_read_in);
511 req->in.args[0].value = inarg;
513 req->out.numargs = 1;
514 req->out.args[0].size = count;
517 static void fuse_release_user_pages(struct fuse_req *req, int write)
521 for (i = 0; i < req->num_pages; i++) {
522 struct page *page = req->pages[i];
524 set_page_dirty_lock(page);
530 * In case of short read, the caller sets 'pos' to the position of
531 * actual end of fuse request in IO request. Otherwise, if bytes_requested
532 * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.
535 * User requested DIO read of 64K. It was splitted into two 32K fuse requests,
536 * both submitted asynchronously. The first of them was ACKed by userspace as
537 * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The
538 * second request was ACKed as short, e.g. only 1K was read, resulting in
541 * Thus, when all fuse requests are completed, the minimal non-negative 'pos'
542 * will be equal to the length of the longest contiguous fragment of
543 * transferred data starting from the beginning of IO request.
545 static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
549 spin_lock(&io->lock);
551 io->err = io->err ? : err;
552 else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes))
556 spin_unlock(&io->lock);
563 else if (io->bytes >= 0 && io->write)
566 res = io->bytes < 0 ? io->size : io->bytes;
568 if (!is_sync_kiocb(io->iocb)) {
569 struct inode *inode = file_inode(io->iocb->ki_filp);
570 struct fuse_conn *fc = get_fuse_conn(inode);
571 struct fuse_inode *fi = get_fuse_inode(inode);
573 spin_lock(&fc->lock);
574 fi->attr_version = ++fc->attr_version;
575 spin_unlock(&fc->lock);
579 aio_complete(io->iocb, res, 0);
584 static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
586 struct fuse_io_priv *io = req->io;
589 fuse_release_user_pages(req, !io->write);
592 if (req->misc.write.in.size != req->misc.write.out.size)
593 pos = req->misc.write.in.offset - io->offset +
594 req->misc.write.out.size;
596 if (req->misc.read.in.size != req->out.args[0].size)
597 pos = req->misc.read.in.offset - io->offset +
598 req->out.args[0].size;
601 fuse_aio_complete(io, req->out.h.error, pos);
604 static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
605 size_t num_bytes, struct fuse_io_priv *io)
607 spin_lock(&io->lock);
608 io->size += num_bytes;
610 spin_unlock(&io->lock);
613 req->end = fuse_aio_complete_req;
615 __fuse_get_request(req);
616 fuse_request_send_background(fc, req);
621 static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
622 loff_t pos, size_t count, fl_owner_t owner)
624 struct file *file = io->file;
625 struct fuse_file *ff = file->private_data;
626 struct fuse_conn *fc = ff->fc;
628 fuse_read_fill(req, file, pos, count, FUSE_READ);
630 struct fuse_read_in *inarg = &req->misc.read.in;
632 inarg->read_flags |= FUSE_READ_LOCKOWNER;
633 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
637 return fuse_async_req_send(fc, req, count, io);
639 fuse_request_send(fc, req);
640 return req->out.args[0].size;
643 static void fuse_read_update_size(struct inode *inode, loff_t size,
646 struct fuse_conn *fc = get_fuse_conn(inode);
647 struct fuse_inode *fi = get_fuse_inode(inode);
649 spin_lock(&fc->lock);
650 if (attr_ver == fi->attr_version && size < inode->i_size &&
651 !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
652 fi->attr_version = ++fc->attr_version;
653 i_size_write(inode, size);
655 spin_unlock(&fc->lock);
658 static int fuse_readpage(struct file *file, struct page *page)
660 struct fuse_io_priv io = { .async = 0, .file = file };
661 struct inode *inode = page->mapping->host;
662 struct fuse_conn *fc = get_fuse_conn(inode);
663 struct fuse_req *req;
665 loff_t pos = page_offset(page);
666 size_t count = PAGE_CACHE_SIZE;
671 if (is_bad_inode(inode))
675 * Page writeback can extend beyond the lifetime of the
676 * page-cache page, so make sure we read a properly synced
679 fuse_wait_on_page_writeback(inode, page->index);
681 req = fuse_get_req(fc, 1);
686 attr_ver = fuse_get_attr_version(fc);
688 req->out.page_zeroing = 1;
689 req->out.argpages = 1;
691 req->pages[0] = page;
692 req->page_descs[0].length = count;
693 num_read = fuse_send_read(req, &io, pos, count, NULL);
694 err = req->out.h.error;
695 fuse_put_request(fc, req);
699 * Short read means EOF. If file size is larger, truncate it
701 if (num_read < count)
702 fuse_read_update_size(inode, pos + num_read, attr_ver);
704 SetPageUptodate(page);
707 fuse_invalidate_atime(inode);
713 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
716 size_t count = req->misc.read.in.size;
717 size_t num_read = req->out.args[0].size;
718 struct address_space *mapping = NULL;
720 for (i = 0; mapping == NULL && i < req->num_pages; i++)
721 mapping = req->pages[i]->mapping;
724 struct inode *inode = mapping->host;
727 * Short read means EOF. If file size is larger, truncate it
729 if (!req->out.h.error && num_read < count) {
732 pos = page_offset(req->pages[0]) + num_read;
733 fuse_read_update_size(inode, pos,
734 req->misc.read.attr_ver);
736 fuse_invalidate_atime(inode);
739 for (i = 0; i < req->num_pages; i++) {
740 struct page *page = req->pages[i];
741 if (!req->out.h.error)
742 SetPageUptodate(page);
746 page_cache_release(page);
749 fuse_file_put(req->ff, false);
752 static void fuse_send_readpages(struct fuse_req *req, struct file *file)
754 struct fuse_file *ff = file->private_data;
755 struct fuse_conn *fc = ff->fc;
756 loff_t pos = page_offset(req->pages[0]);
757 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
759 req->out.argpages = 1;
760 req->out.page_zeroing = 1;
761 req->out.page_replace = 1;
762 fuse_read_fill(req, file, pos, count, FUSE_READ);
763 req->misc.read.attr_ver = fuse_get_attr_version(fc);
764 if (fc->async_read) {
765 req->ff = fuse_file_get(ff);
766 req->end = fuse_readpages_end;
767 fuse_request_send_background(fc, req);
769 fuse_request_send(fc, req);
770 fuse_readpages_end(fc, req);
771 fuse_put_request(fc, req);
775 struct fuse_fill_data {
776 struct fuse_req *req;
782 static int fuse_readpages_fill(void *_data, struct page *page)
784 struct fuse_fill_data *data = _data;
785 struct fuse_req *req = data->req;
786 struct inode *inode = data->inode;
787 struct fuse_conn *fc = get_fuse_conn(inode);
789 fuse_wait_on_page_writeback(inode, page->index);
791 if (req->num_pages &&
792 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
793 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
794 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
795 int nr_alloc = min_t(unsigned, data->nr_pages,
796 FUSE_MAX_PAGES_PER_REQ);
797 fuse_send_readpages(req, data->file);
799 req = fuse_get_req_for_background(fc, nr_alloc);
801 req = fuse_get_req(fc, nr_alloc);
810 if (WARN_ON(req->num_pages >= req->max_pages)) {
811 fuse_put_request(fc, req);
815 page_cache_get(page);
816 req->pages[req->num_pages] = page;
817 req->page_descs[req->num_pages].length = PAGE_SIZE;
823 static int fuse_readpages(struct file *file, struct address_space *mapping,
824 struct list_head *pages, unsigned nr_pages)
826 struct inode *inode = mapping->host;
827 struct fuse_conn *fc = get_fuse_conn(inode);
828 struct fuse_fill_data data;
830 int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ);
833 if (is_bad_inode(inode))
839 data.req = fuse_get_req_for_background(fc, nr_alloc);
841 data.req = fuse_get_req(fc, nr_alloc);
842 data.nr_pages = nr_pages;
843 err = PTR_ERR(data.req);
844 if (IS_ERR(data.req))
847 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
849 if (data.req->num_pages)
850 fuse_send_readpages(data.req, file);
852 fuse_put_request(fc, data.req);
858 static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
859 unsigned long nr_segs, loff_t pos)
861 struct inode *inode = iocb->ki_filp->f_mapping->host;
862 struct fuse_conn *fc = get_fuse_conn(inode);
865 * In auto invalidate mode, always update attributes on read.
866 * Otherwise, only update if we attempt to read past EOF (to ensure
867 * i_size is up to date).
869 if (fc->auto_inval_data ||
870 (pos + iov_length(iov, nr_segs) > i_size_read(inode))) {
872 err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
877 return generic_file_aio_read(iocb, iov, nr_segs, pos);
880 static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
881 loff_t pos, size_t count)
883 struct fuse_write_in *inarg = &req->misc.write.in;
884 struct fuse_write_out *outarg = &req->misc.write.out;
889 req->in.h.opcode = FUSE_WRITE;
890 req->in.h.nodeid = ff->nodeid;
892 if (ff->fc->minor < 9)
893 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
895 req->in.args[0].size = sizeof(struct fuse_write_in);
896 req->in.args[0].value = inarg;
897 req->in.args[1].size = count;
898 req->out.numargs = 1;
899 req->out.args[0].size = sizeof(struct fuse_write_out);
900 req->out.args[0].value = outarg;
903 static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
904 loff_t pos, size_t count, fl_owner_t owner)
906 struct file *file = io->file;
907 struct fuse_file *ff = file->private_data;
908 struct fuse_conn *fc = ff->fc;
909 struct fuse_write_in *inarg = &req->misc.write.in;
911 fuse_write_fill(req, ff, pos, count);
912 inarg->flags = file->f_flags;
914 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
915 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
919 return fuse_async_req_send(fc, req, count, io);
921 fuse_request_send(fc, req);
922 return req->misc.write.out.size;
925 void fuse_write_update_size(struct inode *inode, loff_t pos)
927 struct fuse_conn *fc = get_fuse_conn(inode);
928 struct fuse_inode *fi = get_fuse_inode(inode);
930 spin_lock(&fc->lock);
931 fi->attr_version = ++fc->attr_version;
932 if (pos > inode->i_size)
933 i_size_write(inode, pos);
934 spin_unlock(&fc->lock);
937 static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
938 struct inode *inode, loff_t pos,
944 struct fuse_io_priv io = { .async = 0, .file = file };
946 for (i = 0; i < req->num_pages; i++)
947 fuse_wait_on_page_writeback(inode, req->pages[i]->index);
949 res = fuse_send_write(req, &io, pos, count, NULL);
951 offset = req->page_descs[0].offset;
953 for (i = 0; i < req->num_pages; i++) {
954 struct page *page = req->pages[i];
956 if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
957 SetPageUptodate(page);
959 if (count > PAGE_CACHE_SIZE - offset)
960 count -= PAGE_CACHE_SIZE - offset;
966 page_cache_release(page);
972 static ssize_t fuse_fill_write_pages(struct fuse_req *req,
973 struct address_space *mapping,
974 struct iov_iter *ii, loff_t pos)
976 struct fuse_conn *fc = get_fuse_conn(mapping->host);
977 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
981 req->in.argpages = 1;
982 req->page_descs[0].offset = offset;
987 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
988 size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
991 bytes = min_t(size_t, bytes, fc->max_write - count);
995 if (iov_iter_fault_in_readable(ii, bytes))
999 page = grab_cache_page_write_begin(mapping, index, 0);
1003 if (mapping_writably_mapped(mapping))
1004 flush_dcache_page(page);
1006 tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
1007 flush_dcache_page(page);
1009 mark_page_accessed(page);
1013 page_cache_release(page);
1014 bytes = min(bytes, iov_iter_single_seg_count(ii));
1019 req->pages[req->num_pages] = page;
1020 req->page_descs[req->num_pages].length = tmp;
1023 iov_iter_advance(ii, tmp);
1027 if (offset == PAGE_CACHE_SIZE)
1030 if (!fc->big_writes)
1032 } while (iov_iter_count(ii) && count < fc->max_write &&
1033 req->num_pages < req->max_pages && offset == 0);
1035 return count > 0 ? count : err;
1038 static inline unsigned fuse_wr_pages(loff_t pos, size_t len)
1040 return min_t(unsigned,
1041 ((pos + len - 1) >> PAGE_CACHE_SHIFT) -
1042 (pos >> PAGE_CACHE_SHIFT) + 1,
1043 FUSE_MAX_PAGES_PER_REQ);
1046 static ssize_t fuse_perform_write(struct file *file,
1047 struct address_space *mapping,
1048 struct iov_iter *ii, loff_t pos)
1050 struct inode *inode = mapping->host;
1051 struct fuse_conn *fc = get_fuse_conn(inode);
1052 struct fuse_inode *fi = get_fuse_inode(inode);
1056 if (is_bad_inode(inode))
1059 if (inode->i_size < pos + iov_iter_count(ii))
1060 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1063 struct fuse_req *req;
1065 unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii));
1067 req = fuse_get_req(fc, nr_pages);
1073 count = fuse_fill_write_pages(req, mapping, ii, pos);
1079 num_written = fuse_send_write_pages(req, file, inode,
1081 err = req->out.h.error;
1086 /* break out of the loop on short write */
1087 if (num_written != count)
1091 fuse_put_request(fc, req);
1092 } while (!err && iov_iter_count(ii));
1095 fuse_write_update_size(inode, pos);
1097 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1098 fuse_invalidate_attr(inode);
1100 return res > 0 ? res : err;
1103 static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
1104 unsigned long nr_segs, loff_t pos)
1106 struct file *file = iocb->ki_filp;
1107 struct address_space *mapping = file->f_mapping;
1110 ssize_t written = 0;
1111 ssize_t written_buffered = 0;
1112 struct inode *inode = mapping->host;
1117 WARN_ON(iocb->ki_pos != pos);
1120 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1125 mutex_lock(&inode->i_mutex);
1127 /* We can write back this queue in page reclaim */
1128 current->backing_dev_info = mapping->backing_dev_info;
1130 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1137 err = file_remove_suid(file);
1141 err = file_update_time(file);
1145 if (file->f_flags & O_DIRECT) {
1146 written = generic_file_direct_write(iocb, iov, &nr_segs,
1149 if (written < 0 || written == count)
1155 iov_iter_init(&i, iov, nr_segs, count, written);
1156 written_buffered = fuse_perform_write(file, mapping, &i, pos);
1157 if (written_buffered < 0) {
1158 err = written_buffered;
1161 endbyte = pos + written_buffered - 1;
1163 err = filemap_write_and_wait_range(file->f_mapping, pos,
1168 invalidate_mapping_pages(file->f_mapping,
1169 pos >> PAGE_CACHE_SHIFT,
1170 endbyte >> PAGE_CACHE_SHIFT);
1172 written += written_buffered;
1173 iocb->ki_pos = pos + written_buffered;
1175 iov_iter_init(&i, iov, nr_segs, count, 0);
1176 written = fuse_perform_write(file, mapping, &i, pos);
1178 iocb->ki_pos = pos + written;
1181 current->backing_dev_info = NULL;
1182 mutex_unlock(&inode->i_mutex);
1184 return written ? written : err;
1187 static inline void fuse_page_descs_length_init(struct fuse_req *req,
1188 unsigned index, unsigned nr_pages)
1192 for (i = index; i < index + nr_pages; i++)
1193 req->page_descs[i].length = PAGE_SIZE -
1194 req->page_descs[i].offset;
1197 static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
1199 return (unsigned long)ii->iov->iov_base + ii->iov_offset;
1202 static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
1205 return min(iov_iter_single_seg_count(ii), max_size);
1208 static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
1209 size_t *nbytesp, int write)
1211 size_t nbytes = 0; /* # bytes already packed in req */
1213 /* Special case for kernel I/O: can copy directly into the buffer */
1214 if (segment_eq(get_fs(), KERNEL_DS)) {
1215 unsigned long user_addr = fuse_get_user_addr(ii);
1216 size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
1219 req->in.args[1].value = (void *) user_addr;
1221 req->out.args[0].value = (void *) user_addr;
1223 iov_iter_advance(ii, frag_size);
1224 *nbytesp = frag_size;
1228 while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
1230 unsigned long user_addr = fuse_get_user_addr(ii);
1231 unsigned offset = user_addr & ~PAGE_MASK;
1232 size_t frag_size = fuse_get_frag_size(ii, *nbytesp - nbytes);
1235 unsigned n = req->max_pages - req->num_pages;
1236 frag_size = min_t(size_t, frag_size, n << PAGE_SHIFT);
1238 npages = (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1239 npages = clamp(npages, 1U, n);
1241 ret = get_user_pages_fast(user_addr, npages, !write,
1242 &req->pages[req->num_pages]);
1247 frag_size = min_t(size_t, frag_size,
1248 (npages << PAGE_SHIFT) - offset);
1249 iov_iter_advance(ii, frag_size);
1251 req->page_descs[req->num_pages].offset = offset;
1252 fuse_page_descs_length_init(req, req->num_pages, npages);
1254 req->num_pages += npages;
1255 req->page_descs[req->num_pages - 1].length -=
1256 (npages << PAGE_SHIFT) - offset - frag_size;
1258 nbytes += frag_size;
1262 req->in.argpages = 1;
1264 req->out.argpages = 1;
1271 static inline int fuse_iter_npages(const struct iov_iter *ii_p)
1273 struct iov_iter ii = *ii_p;
1276 while (iov_iter_count(&ii) && npages < FUSE_MAX_PAGES_PER_REQ) {
1277 unsigned long user_addr = fuse_get_user_addr(&ii);
1278 unsigned offset = user_addr & ~PAGE_MASK;
1279 size_t frag_size = iov_iter_single_seg_count(&ii);
1281 npages += (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1282 iov_iter_advance(&ii, frag_size);
1285 return min(npages, FUSE_MAX_PAGES_PER_REQ);
1288 ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
1289 unsigned long nr_segs, size_t count, loff_t *ppos,
1292 struct file *file = io->file;
1293 struct fuse_file *ff = file->private_data;
1294 struct fuse_conn *fc = ff->fc;
1295 size_t nmax = write ? fc->max_write : fc->max_read;
1298 struct fuse_req *req;
1301 iov_iter_init(&ii, iov, nr_segs, count, 0);
1304 req = fuse_get_req_for_background(fc, fuse_iter_npages(&ii));
1306 req = fuse_get_req(fc, fuse_iter_npages(&ii));
1308 return PTR_ERR(req);
1312 fl_owner_t owner = current->files;
1313 size_t nbytes = min(count, nmax);
1314 int err = fuse_get_user_pages(req, &ii, &nbytes, write);
1321 nres = fuse_send_write(req, io, pos, nbytes, owner);
1323 nres = fuse_send_read(req, io, pos, nbytes, owner);
1326 fuse_release_user_pages(req, !write);
1327 if (req->out.h.error) {
1329 res = req->out.h.error;
1331 } else if (nres > nbytes) {
1341 fuse_put_request(fc, req);
1343 req = fuse_get_req_for_background(fc,
1344 fuse_iter_npages(&ii));
1346 req = fuse_get_req(fc, fuse_iter_npages(&ii));
1352 fuse_put_request(fc, req);
1358 EXPORT_SYMBOL_GPL(fuse_direct_io);
1360 static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
1361 const struct iovec *iov,
1362 unsigned long nr_segs, loff_t *ppos,
1366 struct file *file = io->file;
1367 struct inode *inode = file_inode(file);
1369 if (is_bad_inode(inode))
1372 res = fuse_direct_io(io, iov, nr_segs, count, ppos, 0);
1374 fuse_invalidate_attr(inode);
1379 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
1380 size_t count, loff_t *ppos)
1382 struct fuse_io_priv io = { .async = 0, .file = file };
1383 struct iovec iov = { .iov_base = buf, .iov_len = count };
1384 return __fuse_direct_read(&io, &iov, 1, ppos, count);
1387 static ssize_t __fuse_direct_write(struct fuse_io_priv *io,
1388 const struct iovec *iov,
1389 unsigned long nr_segs, loff_t *ppos)
1391 struct file *file = io->file;
1392 struct inode *inode = file_inode(file);
1393 size_t count = iov_length(iov, nr_segs);
1396 res = generic_write_checks(file, ppos, &count, 0);
1398 res = fuse_direct_io(io, iov, nr_segs, count, ppos, 1);
1400 fuse_invalidate_attr(inode);
1405 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
1406 size_t count, loff_t *ppos)
1408 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
1409 struct inode *inode = file_inode(file);
1411 struct fuse_io_priv io = { .async = 0, .file = file };
1413 if (is_bad_inode(inode))
1416 /* Don't allow parallel writes to the same file */
1417 mutex_lock(&inode->i_mutex);
1418 res = __fuse_direct_write(&io, &iov, 1, ppos);
1420 fuse_write_update_size(inode, *ppos);
1421 mutex_unlock(&inode->i_mutex);
1426 static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
1430 for (i = 0; i < req->num_pages; i++)
1431 __free_page(req->pages[i]);
1434 fuse_file_put(req->ff, false);
1437 static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
1439 struct inode *inode = req->inode;
1440 struct fuse_inode *fi = get_fuse_inode(inode);
1441 struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
1444 list_del(&req->writepages_entry);
1445 for (i = 0; i < req->num_pages; i++) {
1446 dec_bdi_stat(bdi, BDI_WRITEBACK);
1447 dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP);
1448 bdi_writeout_inc(bdi);
1450 wake_up(&fi->page_waitq);
1453 /* Called under fc->lock, may release and reacquire it */
1454 static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req,
1456 __releases(fc->lock)
1457 __acquires(fc->lock)
1459 struct fuse_inode *fi = get_fuse_inode(req->inode);
1460 struct fuse_write_in *inarg = &req->misc.write.in;
1461 __u64 data_size = req->num_pages * PAGE_CACHE_SIZE;
1466 if (inarg->offset + data_size <= size) {
1467 inarg->size = data_size;
1468 } else if (inarg->offset < size) {
1469 inarg->size = size - inarg->offset;
1471 /* Got truncated off completely */
1475 req->in.args[1].size = inarg->size;
1477 fuse_request_send_background_locked(fc, req);
1481 fuse_writepage_finish(fc, req);
1482 spin_unlock(&fc->lock);
1483 fuse_writepage_free(fc, req);
1484 fuse_put_request(fc, req);
1485 spin_lock(&fc->lock);
1489 * If fi->writectr is positive (no truncate or fsync going on) send
1490 * all queued writepage requests.
1492 * Called with fc->lock
1494 void fuse_flush_writepages(struct inode *inode)
1495 __releases(fc->lock)
1496 __acquires(fc->lock)
1498 struct fuse_conn *fc = get_fuse_conn(inode);
1499 struct fuse_inode *fi = get_fuse_inode(inode);
1500 size_t crop = i_size_read(inode);
1501 struct fuse_req *req;
1503 while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
1504 req = list_entry(fi->queued_writes.next, struct fuse_req, list);
1505 list_del_init(&req->list);
1506 fuse_send_writepage(fc, req, crop);
1510 static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
1512 struct inode *inode = req->inode;
1513 struct fuse_inode *fi = get_fuse_inode(inode);
1515 mapping_set_error(inode->i_mapping, req->out.h.error);
1516 spin_lock(&fc->lock);
1517 while (req->misc.write.next) {
1518 struct fuse_conn *fc = get_fuse_conn(inode);
1519 struct fuse_write_in *inarg = &req->misc.write.in;
1520 struct fuse_req *next = req->misc.write.next;
1521 req->misc.write.next = next->misc.write.next;
1522 next->misc.write.next = NULL;
1523 next->ff = fuse_file_get(req->ff);
1524 list_add(&next->writepages_entry, &fi->writepages);
1527 * Skip fuse_flush_writepages() to make it easy to crop requests
1528 * based on primary request size.
1530 * 1st case (trivial): there are no concurrent activities using
1531 * fuse_set/release_nowrite. Then we're on safe side because
1532 * fuse_flush_writepages() would call fuse_send_writepage()
1535 * 2nd case: someone called fuse_set_nowrite and it is waiting
1536 * now for completion of all in-flight requests. This happens
1537 * rarely and no more than once per page, so this should be
1540 * 3rd case: someone (e.g. fuse_do_setattr()) is in the middle
1541 * of fuse_set_nowrite..fuse_release_nowrite section. The fact
1542 * that fuse_set_nowrite returned implies that all in-flight
1543 * requests were completed along with all of their secondary
1544 * requests. Further primary requests are blocked by negative
1545 * writectr. Hence there cannot be any in-flight requests and
1546 * no invocations of fuse_writepage_end() while we're in
1547 * fuse_set_nowrite..fuse_release_nowrite section.
1549 fuse_send_writepage(fc, next, inarg->offset + inarg->size);
1552 fuse_writepage_finish(fc, req);
1553 spin_unlock(&fc->lock);
1554 fuse_writepage_free(fc, req);
1557 static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc,
1558 struct fuse_inode *fi)
1560 struct fuse_file *ff = NULL;
1562 spin_lock(&fc->lock);
1563 if (!WARN_ON(list_empty(&fi->write_files))) {
1564 ff = list_entry(fi->write_files.next, struct fuse_file,
1568 spin_unlock(&fc->lock);
1573 static int fuse_writepage_locked(struct page *page)
1575 struct address_space *mapping = page->mapping;
1576 struct inode *inode = mapping->host;
1577 struct fuse_conn *fc = get_fuse_conn(inode);
1578 struct fuse_inode *fi = get_fuse_inode(inode);
1579 struct fuse_req *req;
1580 struct page *tmp_page;
1581 int error = -ENOMEM;
1583 set_page_writeback(page);
1585 req = fuse_request_alloc_nofs(1);
1589 req->background = 1; /* writeback always goes to bg_queue */
1590 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1595 req->ff = fuse_write_file_get(fc, fi);
1599 fuse_write_fill(req, req->ff, page_offset(page), 0);
1601 copy_highpage(tmp_page, page);
1602 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1603 req->misc.write.next = NULL;
1604 req->in.argpages = 1;
1606 req->pages[0] = tmp_page;
1607 req->page_descs[0].offset = 0;
1608 req->page_descs[0].length = PAGE_SIZE;
1609 req->end = fuse_writepage_end;
1612 inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
1613 inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
1615 spin_lock(&fc->lock);
1616 list_add(&req->writepages_entry, &fi->writepages);
1617 list_add_tail(&req->list, &fi->queued_writes);
1618 fuse_flush_writepages(inode);
1619 spin_unlock(&fc->lock);
1621 end_page_writeback(page);
1626 fuse_request_free(req);
1628 end_page_writeback(page);
1632 static int fuse_writepage(struct page *page, struct writeback_control *wbc)
1636 if (fuse_page_is_writeback(page->mapping->host, page->index)) {
1638 * ->writepages() should be called for sync() and friends. We
1639 * should only get here on direct reclaim and then we are
1640 * allowed to skip a page which is already in flight
1642 WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
1644 redirty_page_for_writepage(wbc, page);
1648 err = fuse_writepage_locked(page);
1654 struct fuse_fill_wb_data {
1655 struct fuse_req *req;
1656 struct fuse_file *ff;
1657 struct inode *inode;
1658 struct page **orig_pages;
1661 static void fuse_writepages_send(struct fuse_fill_wb_data *data)
1663 struct fuse_req *req = data->req;
1664 struct inode *inode = data->inode;
1665 struct fuse_conn *fc = get_fuse_conn(inode);
1666 struct fuse_inode *fi = get_fuse_inode(inode);
1667 int num_pages = req->num_pages;
1670 req->ff = fuse_file_get(data->ff);
1671 spin_lock(&fc->lock);
1672 list_add_tail(&req->list, &fi->queued_writes);
1673 fuse_flush_writepages(inode);
1674 spin_unlock(&fc->lock);
1676 for (i = 0; i < num_pages; i++)
1677 end_page_writeback(data->orig_pages[i]);
1680 static bool fuse_writepage_in_flight(struct fuse_req *new_req,
1683 struct fuse_conn *fc = get_fuse_conn(new_req->inode);
1684 struct fuse_inode *fi = get_fuse_inode(new_req->inode);
1685 struct fuse_req *tmp;
1686 struct fuse_req *old_req;
1690 BUG_ON(new_req->num_pages != 0);
1692 spin_lock(&fc->lock);
1693 list_del(&new_req->writepages_entry);
1694 list_for_each_entry(old_req, &fi->writepages, writepages_entry) {
1695 BUG_ON(old_req->inode != new_req->inode);
1696 curr_index = old_req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
1697 if (curr_index <= page->index &&
1698 page->index < curr_index + old_req->num_pages) {
1704 list_add(&new_req->writepages_entry, &fi->writepages);
1708 new_req->num_pages = 1;
1709 for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) {
1710 BUG_ON(tmp->inode != new_req->inode);
1711 curr_index = tmp->misc.write.in.offset >> PAGE_CACHE_SHIFT;
1712 if (tmp->num_pages == 1 &&
1713 curr_index == page->index) {
1718 if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT ||
1719 old_req->state == FUSE_REQ_PENDING)) {
1720 struct backing_dev_info *bdi = page->mapping->backing_dev_info;
1722 copy_highpage(old_req->pages[0], page);
1723 spin_unlock(&fc->lock);
1725 dec_bdi_stat(bdi, BDI_WRITEBACK);
1726 dec_zone_page_state(page, NR_WRITEBACK_TEMP);
1727 bdi_writeout_inc(bdi);
1728 fuse_writepage_free(fc, new_req);
1729 fuse_request_free(new_req);
1732 new_req->misc.write.next = old_req->misc.write.next;
1733 old_req->misc.write.next = new_req;
1736 spin_unlock(&fc->lock);
1741 static int fuse_writepages_fill(struct page *page,
1742 struct writeback_control *wbc, void *_data)
1744 struct fuse_fill_wb_data *data = _data;
1745 struct fuse_req *req = data->req;
1746 struct inode *inode = data->inode;
1747 struct fuse_conn *fc = get_fuse_conn(inode);
1748 struct page *tmp_page;
1754 data->ff = fuse_write_file_get(fc, get_fuse_inode(inode));
1760 * Being under writeback is unlikely but possible. For example direct
1761 * read to an mmaped fuse file will set the page dirty twice; once when
1762 * the pages are faulted with get_user_pages(), and then after the read
1765 is_writeback = fuse_page_is_writeback(inode, page->index);
1767 if (req && req->num_pages &&
1768 (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
1769 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_write ||
1770 data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) {
1771 fuse_writepages_send(data);
1775 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1780 * The page must not be redirtied until the writeout is completed
1781 * (i.e. userspace has sent a reply to the write request). Otherwise
1782 * there could be more than one temporary page instance for each real
1785 * This is ensured by holding the page lock in page_mkwrite() while
1786 * checking fuse_page_is_writeback(). We already hold the page lock
1787 * since clear_page_dirty_for_io() and keep it held until we add the
1788 * request to the fi->writepages list and increment req->num_pages.
1789 * After this fuse_page_is_writeback() will indicate that the page is
1790 * under writeback, so we can release the page lock.
1792 if (data->req == NULL) {
1793 struct fuse_inode *fi = get_fuse_inode(inode);
1796 req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ);
1798 __free_page(tmp_page);
1802 fuse_write_fill(req, data->ff, page_offset(page), 0);
1803 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1804 req->misc.write.next = NULL;
1805 req->in.argpages = 1;
1806 req->background = 1;
1808 req->end = fuse_writepage_end;
1811 spin_lock(&fc->lock);
1812 list_add(&req->writepages_entry, &fi->writepages);
1813 spin_unlock(&fc->lock);
1817 set_page_writeback(page);
1819 copy_highpage(tmp_page, page);
1820 req->pages[req->num_pages] = tmp_page;
1821 req->page_descs[req->num_pages].offset = 0;
1822 req->page_descs[req->num_pages].length = PAGE_SIZE;
1824 inc_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK);
1825 inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
1828 if (is_writeback && fuse_writepage_in_flight(req, page)) {
1829 end_page_writeback(page);
1833 data->orig_pages[req->num_pages] = page;
1836 * Protected by fc->lock against concurrent access by
1837 * fuse_page_is_writeback().
1839 spin_lock(&fc->lock);
1841 spin_unlock(&fc->lock);
1849 static int fuse_writepages(struct address_space *mapping,
1850 struct writeback_control *wbc)
1852 struct inode *inode = mapping->host;
1853 struct fuse_fill_wb_data data;
1857 if (is_bad_inode(inode))
1865 data.orig_pages = kzalloc(sizeof(struct page *) *
1866 FUSE_MAX_PAGES_PER_REQ,
1868 if (!data.orig_pages)
1871 err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data);
1873 /* Ignore errors if we can write at least one page */
1874 BUG_ON(!data.req->num_pages);
1875 fuse_writepages_send(&data);
1879 fuse_file_put(data.ff, false);
1881 kfree(data.orig_pages);
1886 static int fuse_launder_page(struct page *page)
1889 if (clear_page_dirty_for_io(page)) {
1890 struct inode *inode = page->mapping->host;
1891 err = fuse_writepage_locked(page);
1893 fuse_wait_on_page_writeback(inode, page->index);
1899 * Write back dirty pages now, because there may not be any suitable
1902 static void fuse_vma_close(struct vm_area_struct *vma)
1904 filemap_write_and_wait(vma->vm_file->f_mapping);
1908 * Wait for writeback against this page to complete before allowing it
1909 * to be marked dirty again, and hence written back again, possibly
1910 * before the previous writepage completed.
1912 * Block here, instead of in ->writepage(), so that the userspace fs
1913 * can only block processes actually operating on the filesystem.
1915 * Otherwise unprivileged userspace fs would be able to block
1920 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
1922 static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1924 struct page *page = vmf->page;
1925 struct inode *inode = file_inode(vma->vm_file);
1927 file_update_time(vma->vm_file);
1929 if (page->mapping != inode->i_mapping) {
1931 return VM_FAULT_NOPAGE;
1934 fuse_wait_on_page_writeback(inode, page->index);
1935 return VM_FAULT_LOCKED;
1938 static const struct vm_operations_struct fuse_file_vm_ops = {
1939 .close = fuse_vma_close,
1940 .fault = filemap_fault,
1941 .page_mkwrite = fuse_page_mkwrite,
1942 .remap_pages = generic_file_remap_pages,
1945 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
1947 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
1948 struct inode *inode = file_inode(file);
1949 struct fuse_conn *fc = get_fuse_conn(inode);
1950 struct fuse_inode *fi = get_fuse_inode(inode);
1951 struct fuse_file *ff = file->private_data;
1953 * file may be written through mmap, so chain it onto the
1954 * inodes's write_file list
1956 spin_lock(&fc->lock);
1957 if (list_empty(&ff->write_entry))
1958 list_add(&ff->write_entry, &fi->write_files);
1959 spin_unlock(&fc->lock);
1961 file_accessed(file);
1962 vma->vm_ops = &fuse_file_vm_ops;
1966 static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
1968 /* Can't provide the coherency needed for MAP_SHARED */
1969 if (vma->vm_flags & VM_MAYSHARE)
1972 invalidate_inode_pages2(file->f_mapping);
1974 return generic_file_mmap(file, vma);
1977 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
1978 struct file_lock *fl)
1980 switch (ffl->type) {
1986 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
1987 ffl->end < ffl->start)
1990 fl->fl_start = ffl->start;
1991 fl->fl_end = ffl->end;
1992 fl->fl_pid = ffl->pid;
1998 fl->fl_type = ffl->type;
2002 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
2003 const struct file_lock *fl, int opcode, pid_t pid,
2006 struct inode *inode = file_inode(file);
2007 struct fuse_conn *fc = get_fuse_conn(inode);
2008 struct fuse_file *ff = file->private_data;
2009 struct fuse_lk_in *arg = &req->misc.lk_in;
2012 arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
2013 arg->lk.start = fl->fl_start;
2014 arg->lk.end = fl->fl_end;
2015 arg->lk.type = fl->fl_type;
2018 arg->lk_flags |= FUSE_LK_FLOCK;
2019 req->in.h.opcode = opcode;
2020 req->in.h.nodeid = get_node_id(inode);
2021 req->in.numargs = 1;
2022 req->in.args[0].size = sizeof(*arg);
2023 req->in.args[0].value = arg;
2026 static int fuse_getlk(struct file *file, struct file_lock *fl)
2028 struct inode *inode = file_inode(file);
2029 struct fuse_conn *fc = get_fuse_conn(inode);
2030 struct fuse_req *req;
2031 struct fuse_lk_out outarg;
2034 req = fuse_get_req_nopages(fc);
2036 return PTR_ERR(req);
2038 fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
2039 req->out.numargs = 1;
2040 req->out.args[0].size = sizeof(outarg);
2041 req->out.args[0].value = &outarg;
2042 fuse_request_send(fc, req);
2043 err = req->out.h.error;
2044 fuse_put_request(fc, req);
2046 err = convert_fuse_file_lock(&outarg.lk, fl);
2051 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
2053 struct inode *inode = file_inode(file);
2054 struct fuse_conn *fc = get_fuse_conn(inode);
2055 struct fuse_req *req;
2056 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
2057 pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
2060 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
2061 /* NLM needs asynchronous locks, which we don't support yet */
2065 /* Unlock on close is handled by the flush method */
2066 if (fl->fl_flags & FL_CLOSE)
2069 req = fuse_get_req_nopages(fc);
2071 return PTR_ERR(req);
2073 fuse_lk_fill(req, file, fl, opcode, pid, flock);
2074 fuse_request_send(fc, req);
2075 err = req->out.h.error;
2076 /* locking is restartable */
2079 fuse_put_request(fc, req);
2083 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
2085 struct inode *inode = file_inode(file);
2086 struct fuse_conn *fc = get_fuse_conn(inode);
2089 if (cmd == F_CANCELLK) {
2091 } else if (cmd == F_GETLK) {
2093 posix_test_lock(file, fl);
2096 err = fuse_getlk(file, fl);
2099 err = posix_lock_file(file, fl, NULL);
2101 err = fuse_setlk(file, fl, 0);
2106 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
2108 struct inode *inode = file_inode(file);
2109 struct fuse_conn *fc = get_fuse_conn(inode);
2113 err = flock_lock_file_wait(file, fl);
2115 struct fuse_file *ff = file->private_data;
2117 /* emulate flock with POSIX locks */
2118 fl->fl_owner = (fl_owner_t) file;
2120 err = fuse_setlk(file, fl, 1);
2126 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
2128 struct inode *inode = mapping->host;
2129 struct fuse_conn *fc = get_fuse_conn(inode);
2130 struct fuse_req *req;
2131 struct fuse_bmap_in inarg;
2132 struct fuse_bmap_out outarg;
2135 if (!inode->i_sb->s_bdev || fc->no_bmap)
2138 req = fuse_get_req_nopages(fc);
2142 memset(&inarg, 0, sizeof(inarg));
2143 inarg.block = block;
2144 inarg.blocksize = inode->i_sb->s_blocksize;
2145 req->in.h.opcode = FUSE_BMAP;
2146 req->in.h.nodeid = get_node_id(inode);
2147 req->in.numargs = 1;
2148 req->in.args[0].size = sizeof(inarg);
2149 req->in.args[0].value = &inarg;
2150 req->out.numargs = 1;
2151 req->out.args[0].size = sizeof(outarg);
2152 req->out.args[0].value = &outarg;
2153 fuse_request_send(fc, req);
2154 err = req->out.h.error;
2155 fuse_put_request(fc, req);
2159 return err ? 0 : outarg.block;
2162 static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
2165 struct inode *inode = file_inode(file);
2167 /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
2168 if (whence == SEEK_CUR || whence == SEEK_SET)
2169 return generic_file_llseek(file, offset, whence);
2171 mutex_lock(&inode->i_mutex);
2172 retval = fuse_update_attributes(inode, NULL, file, NULL);
2174 retval = generic_file_llseek(file, offset, whence);
2175 mutex_unlock(&inode->i_mutex);
2180 static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
2181 unsigned int nr_segs, size_t bytes, bool to_user)
2189 iov_iter_init(&ii, iov, nr_segs, bytes, 0);
2191 while (iov_iter_count(&ii)) {
2192 struct page *page = pages[page_idx++];
2193 size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
2199 char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
2200 size_t iov_len = ii.iov->iov_len - ii.iov_offset;
2201 size_t copy = min(todo, iov_len);
2205 left = copy_from_user(kaddr, uaddr, copy);
2207 left = copy_to_user(uaddr, kaddr, copy);
2212 iov_iter_advance(&ii, copy);
2224 * CUSE servers compiled on 32bit broke on 64bit kernels because the
2225 * ABI was defined to be 'struct iovec' which is different on 32bit
2226 * and 64bit. Fortunately we can determine which structure the server
2227 * used from the size of the reply.
2229 static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
2230 size_t transferred, unsigned count,
2233 #ifdef CONFIG_COMPAT
2234 if (count * sizeof(struct compat_iovec) == transferred) {
2235 struct compat_iovec *ciov = src;
2239 * With this interface a 32bit server cannot support
2240 * non-compat (i.e. ones coming from 64bit apps) ioctl
2246 for (i = 0; i < count; i++) {
2247 dst[i].iov_base = compat_ptr(ciov[i].iov_base);
2248 dst[i].iov_len = ciov[i].iov_len;
2254 if (count * sizeof(struct iovec) != transferred)
2257 memcpy(dst, src, transferred);
2261 /* Make sure iov_length() won't overflow */
2262 static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
2265 u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
2267 for (n = 0; n < count; n++, iov++) {
2268 if (iov->iov_len > (size_t) max)
2270 max -= iov->iov_len;
2275 static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
2276 void *src, size_t transferred, unsigned count,
2280 struct fuse_ioctl_iovec *fiov = src;
2282 if (fc->minor < 16) {
2283 return fuse_copy_ioctl_iovec_old(dst, src, transferred,
2287 if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
2290 for (i = 0; i < count; i++) {
2291 /* Did the server supply an inappropriate value? */
2292 if (fiov[i].base != (unsigned long) fiov[i].base ||
2293 fiov[i].len != (unsigned long) fiov[i].len)
2296 dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
2297 dst[i].iov_len = (size_t) fiov[i].len;
2299 #ifdef CONFIG_COMPAT
2301 (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
2302 (compat_size_t) dst[i].iov_len != fiov[i].len))
2312 * For ioctls, there is no generic way to determine how much memory
2313 * needs to be read and/or written. Furthermore, ioctls are allowed
2314 * to dereference the passed pointer, so the parameter requires deep
2315 * copying but FUSE has no idea whatsoever about what to copy in or
2318 * This is solved by allowing FUSE server to retry ioctl with
2319 * necessary in/out iovecs. Let's assume the ioctl implementation
2320 * needs to read in the following structure.
2327 * On the first callout to FUSE server, inarg->in_size and
2328 * inarg->out_size will be NULL; then, the server completes the ioctl
2329 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
2330 * the actual iov array to
2332 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
2334 * which tells FUSE to copy in the requested area and retry the ioctl.
2335 * On the second round, the server has access to the structure and
2336 * from that it can tell what to look for next, so on the invocation,
2337 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
2339 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
2340 * { .iov_base = a.buf, .iov_len = a.buflen } }
2342 * FUSE will copy both struct a and the pointed buffer from the
2343 * process doing the ioctl and retry ioctl with both struct a and the
2346 * This time, FUSE server has everything it needs and completes ioctl
2347 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
2349 * Copying data out works the same way.
2351 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
2352 * automatically initializes in and out iovs by decoding @cmd with
2353 * _IOC_* macros and the server is not allowed to request RETRY. This
2354 * limits ioctl data transfers to well-formed ioctls and is the forced
2355 * behavior for all FUSE servers.
2357 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
2360 struct fuse_file *ff = file->private_data;
2361 struct fuse_conn *fc = ff->fc;
2362 struct fuse_ioctl_in inarg = {
2368 struct fuse_ioctl_out outarg;
2369 struct fuse_req *req = NULL;
2370 struct page **pages = NULL;
2371 struct iovec *iov_page = NULL;
2372 struct iovec *in_iov = NULL, *out_iov = NULL;
2373 unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
2374 size_t in_size, out_size, transferred;
2377 #if BITS_PER_LONG == 32
2378 inarg.flags |= FUSE_IOCTL_32BIT;
2380 if (flags & FUSE_IOCTL_COMPAT)
2381 inarg.flags |= FUSE_IOCTL_32BIT;
2384 /* assume all the iovs returned by client always fits in a page */
2385 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
2388 pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL);
2389 iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
2390 if (!pages || !iov_page)
2394 * If restricted, initialize IO parameters as encoded in @cmd.
2395 * RETRY from server is not allowed.
2397 if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
2398 struct iovec *iov = iov_page;
2400 iov->iov_base = (void __user *)arg;
2401 iov->iov_len = _IOC_SIZE(cmd);
2403 if (_IOC_DIR(cmd) & _IOC_WRITE) {
2408 if (_IOC_DIR(cmd) & _IOC_READ) {
2415 inarg.in_size = in_size = iov_length(in_iov, in_iovs);
2416 inarg.out_size = out_size = iov_length(out_iov, out_iovs);
2419 * Out data can be used either for actual out data or iovs,
2420 * make sure there always is at least one page.
2422 out_size = max_t(size_t, out_size, PAGE_SIZE);
2423 max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
2425 /* make sure there are enough buffer pages and init request with them */
2427 if (max_pages > FUSE_MAX_PAGES_PER_REQ)
2429 while (num_pages < max_pages) {
2430 pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
2431 if (!pages[num_pages])
2436 req = fuse_get_req(fc, num_pages);
2442 memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
2443 req->num_pages = num_pages;
2444 fuse_page_descs_length_init(req, 0, req->num_pages);
2446 /* okay, let's send it to the client */
2447 req->in.h.opcode = FUSE_IOCTL;
2448 req->in.h.nodeid = ff->nodeid;
2449 req->in.numargs = 1;
2450 req->in.args[0].size = sizeof(inarg);
2451 req->in.args[0].value = &inarg;
2454 req->in.args[1].size = in_size;
2455 req->in.argpages = 1;
2457 err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
2463 req->out.numargs = 2;
2464 req->out.args[0].size = sizeof(outarg);
2465 req->out.args[0].value = &outarg;
2466 req->out.args[1].size = out_size;
2467 req->out.argpages = 1;
2468 req->out.argvar = 1;
2470 fuse_request_send(fc, req);
2471 err = req->out.h.error;
2472 transferred = req->out.args[1].size;
2473 fuse_put_request(fc, req);
2478 /* did it ask for retry? */
2479 if (outarg.flags & FUSE_IOCTL_RETRY) {
2482 /* no retry if in restricted mode */
2484 if (!(flags & FUSE_IOCTL_UNRESTRICTED))
2487 in_iovs = outarg.in_iovs;
2488 out_iovs = outarg.out_iovs;
2491 * Make sure things are in boundary, separate checks
2492 * are to protect against overflow.
2495 if (in_iovs > FUSE_IOCTL_MAX_IOV ||
2496 out_iovs > FUSE_IOCTL_MAX_IOV ||
2497 in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
2500 vaddr = kmap_atomic(pages[0]);
2501 err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
2502 transferred, in_iovs + out_iovs,
2503 (flags & FUSE_IOCTL_COMPAT) != 0);
2504 kunmap_atomic(vaddr);
2509 out_iov = in_iov + in_iovs;
2511 err = fuse_verify_ioctl_iov(in_iov, in_iovs);
2515 err = fuse_verify_ioctl_iov(out_iov, out_iovs);
2523 if (transferred > inarg.out_size)
2526 err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
2529 fuse_put_request(fc, req);
2530 free_page((unsigned long) iov_page);
2532 __free_page(pages[--num_pages]);
2535 return err ? err : outarg.result;
2537 EXPORT_SYMBOL_GPL(fuse_do_ioctl);
2539 long fuse_ioctl_common(struct file *file, unsigned int cmd,
2540 unsigned long arg, unsigned int flags)
2542 struct inode *inode = file_inode(file);
2543 struct fuse_conn *fc = get_fuse_conn(inode);
2545 if (!fuse_allow_current_process(fc))
2548 if (is_bad_inode(inode))
2551 return fuse_do_ioctl(file, cmd, arg, flags);
2554 static long fuse_file_ioctl(struct file *file, unsigned int cmd,
2557 return fuse_ioctl_common(file, cmd, arg, 0);
2560 static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
2563 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
2567 * All files which have been polled are linked to RB tree
2568 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2569 * find the matching one.
2571 static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
2572 struct rb_node **parent_out)
2574 struct rb_node **link = &fc->polled_files.rb_node;
2575 struct rb_node *last = NULL;
2578 struct fuse_file *ff;
2581 ff = rb_entry(last, struct fuse_file, polled_node);
2584 link = &last->rb_left;
2585 else if (kh > ff->kh)
2586 link = &last->rb_right;
2597 * The file is about to be polled. Make sure it's on the polled_files
2598 * RB tree. Note that files once added to the polled_files tree are
2599 * not removed before the file is released. This is because a file
2600 * polled once is likely to be polled again.
2602 static void fuse_register_polled_file(struct fuse_conn *fc,
2603 struct fuse_file *ff)
2605 spin_lock(&fc->lock);
2606 if (RB_EMPTY_NODE(&ff->polled_node)) {
2607 struct rb_node **link, *parent;
2609 link = fuse_find_polled_node(fc, ff->kh, &parent);
2611 rb_link_node(&ff->polled_node, parent, link);
2612 rb_insert_color(&ff->polled_node, &fc->polled_files);
2614 spin_unlock(&fc->lock);
2617 unsigned fuse_file_poll(struct file *file, poll_table *wait)
2619 struct fuse_file *ff = file->private_data;
2620 struct fuse_conn *fc = ff->fc;
2621 struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
2622 struct fuse_poll_out outarg;
2623 struct fuse_req *req;
2627 return DEFAULT_POLLMASK;
2629 poll_wait(file, &ff->poll_wait, wait);
2630 inarg.events = (__u32)poll_requested_events(wait);
2633 * Ask for notification iff there's someone waiting for it.
2634 * The client may ignore the flag and always notify.
2636 if (waitqueue_active(&ff->poll_wait)) {
2637 inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
2638 fuse_register_polled_file(fc, ff);
2641 req = fuse_get_req_nopages(fc);
2645 req->in.h.opcode = FUSE_POLL;
2646 req->in.h.nodeid = ff->nodeid;
2647 req->in.numargs = 1;
2648 req->in.args[0].size = sizeof(inarg);
2649 req->in.args[0].value = &inarg;
2650 req->out.numargs = 1;
2651 req->out.args[0].size = sizeof(outarg);
2652 req->out.args[0].value = &outarg;
2653 fuse_request_send(fc, req);
2654 err = req->out.h.error;
2655 fuse_put_request(fc, req);
2658 return outarg.revents;
2659 if (err == -ENOSYS) {
2661 return DEFAULT_POLLMASK;
2665 EXPORT_SYMBOL_GPL(fuse_file_poll);
2668 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2669 * wakes up the poll waiters.
2671 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
2672 struct fuse_notify_poll_wakeup_out *outarg)
2674 u64 kh = outarg->kh;
2675 struct rb_node **link;
2677 spin_lock(&fc->lock);
2679 link = fuse_find_polled_node(fc, kh, NULL);
2681 struct fuse_file *ff;
2683 ff = rb_entry(*link, struct fuse_file, polled_node);
2684 wake_up_interruptible_sync(&ff->poll_wait);
2687 spin_unlock(&fc->lock);
2691 static void fuse_do_truncate(struct file *file)
2693 struct inode *inode = file->f_mapping->host;
2696 attr.ia_valid = ATTR_SIZE;
2697 attr.ia_size = i_size_read(inode);
2699 attr.ia_file = file;
2700 attr.ia_valid |= ATTR_FILE;
2702 fuse_do_setattr(inode, &attr, file);
2705 static inline loff_t fuse_round_up(loff_t off)
2707 return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
2711 fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
2712 loff_t offset, unsigned long nr_segs)
2715 struct file *file = iocb->ki_filp;
2716 struct fuse_file *ff = file->private_data;
2717 bool async_dio = ff->fc->async_dio;
2719 struct inode *inode;
2721 size_t count = iov_length(iov, nr_segs);
2722 struct fuse_io_priv *io;
2725 inode = file->f_mapping->host;
2726 i_size = i_size_read(inode);
2728 if ((rw == READ) && (offset > i_size))
2731 /* optimization for short read */
2732 if (async_dio && rw != WRITE && offset + count > i_size) {
2733 if (offset >= i_size)
2735 count = min_t(loff_t, count, fuse_round_up(i_size - offset));
2738 io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
2741 spin_lock_init(&io->lock);
2745 io->offset = offset;
2746 io->write = (rw == WRITE);
2750 * By default, we want to optimize all I/Os with async request
2751 * submission to the client filesystem if supported.
2753 io->async = async_dio;
2757 * We cannot asynchronously extend the size of a file. We have no method
2758 * to wait on real async I/O requests, so we must submit this request
2761 if (!is_sync_kiocb(iocb) && (offset + count > i_size) && rw == WRITE)
2765 ret = __fuse_direct_write(io, iov, nr_segs, &pos);
2767 ret = __fuse_direct_read(io, iov, nr_segs, &pos, count);
2770 fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
2772 /* we have a non-extending, async request, so return */
2773 if (!is_sync_kiocb(iocb))
2774 return -EIOCBQUEUED;
2776 ret = wait_on_sync_kiocb(iocb);
2783 fuse_write_update_size(inode, pos);
2784 else if (ret < 0 && offset + count > i_size)
2785 fuse_do_truncate(file);
2791 static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
2794 struct fuse_file *ff = file->private_data;
2795 struct inode *inode = file->f_inode;
2796 struct fuse_inode *fi = get_fuse_inode(inode);
2797 struct fuse_conn *fc = ff->fc;
2798 struct fuse_req *req;
2799 struct fuse_fallocate_in inarg = {
2806 bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) ||
2807 (mode & FALLOC_FL_PUNCH_HOLE);
2809 if (fc->no_fallocate)
2813 mutex_lock(&inode->i_mutex);
2814 if (mode & FALLOC_FL_PUNCH_HOLE) {
2815 loff_t endbyte = offset + length - 1;
2816 err = filemap_write_and_wait_range(inode->i_mapping,
2821 fuse_sync_writes(inode);
2825 if (!(mode & FALLOC_FL_KEEP_SIZE))
2826 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
2828 req = fuse_get_req_nopages(fc);
2834 req->in.h.opcode = FUSE_FALLOCATE;
2835 req->in.h.nodeid = ff->nodeid;
2836 req->in.numargs = 1;
2837 req->in.args[0].size = sizeof(inarg);
2838 req->in.args[0].value = &inarg;
2839 fuse_request_send(fc, req);
2840 err = req->out.h.error;
2841 if (err == -ENOSYS) {
2842 fc->no_fallocate = 1;
2845 fuse_put_request(fc, req);
2850 /* we could have extended the file */
2851 if (!(mode & FALLOC_FL_KEEP_SIZE))
2852 fuse_write_update_size(inode, offset + length);
2854 if (mode & FALLOC_FL_PUNCH_HOLE)
2855 truncate_pagecache_range(inode, offset, offset + length - 1);
2857 fuse_invalidate_attr(inode);
2860 if (!(mode & FALLOC_FL_KEEP_SIZE))
2861 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
2864 mutex_unlock(&inode->i_mutex);
2869 static const struct file_operations fuse_file_operations = {
2870 .llseek = fuse_file_llseek,
2871 .read = do_sync_read,
2872 .aio_read = fuse_file_aio_read,
2873 .write = do_sync_write,
2874 .aio_write = fuse_file_aio_write,
2875 .mmap = fuse_file_mmap,
2877 .flush = fuse_flush,
2878 .release = fuse_release,
2879 .fsync = fuse_fsync,
2880 .lock = fuse_file_lock,
2881 .flock = fuse_file_flock,
2882 .splice_read = generic_file_splice_read,
2883 .unlocked_ioctl = fuse_file_ioctl,
2884 .compat_ioctl = fuse_file_compat_ioctl,
2885 .poll = fuse_file_poll,
2886 .fallocate = fuse_file_fallocate,
2889 static const struct file_operations fuse_direct_io_file_operations = {
2890 .llseek = fuse_file_llseek,
2891 .read = fuse_direct_read,
2892 .write = fuse_direct_write,
2893 .mmap = fuse_direct_mmap,
2895 .flush = fuse_flush,
2896 .release = fuse_release,
2897 .fsync = fuse_fsync,
2898 .lock = fuse_file_lock,
2899 .flock = fuse_file_flock,
2900 .unlocked_ioctl = fuse_file_ioctl,
2901 .compat_ioctl = fuse_file_compat_ioctl,
2902 .poll = fuse_file_poll,
2903 .fallocate = fuse_file_fallocate,
2904 /* no splice_read */
2907 static const struct address_space_operations fuse_file_aops = {
2908 .readpage = fuse_readpage,
2909 .writepage = fuse_writepage,
2910 .writepages = fuse_writepages,
2911 .launder_page = fuse_launder_page,
2912 .readpages = fuse_readpages,
2913 .set_page_dirty = __set_page_dirty_nobuffers,
2915 .direct_IO = fuse_direct_IO,
2918 void fuse_init_file_inode(struct inode *inode)
2920 inode->i_fop = &fuse_file_operations;
2921 inode->i_data.a_ops = &fuse_file_aops;