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 static void fuse_link_write_file(struct file *file)
193 struct inode *inode = file_inode(file);
194 struct fuse_conn *fc = get_fuse_conn(inode);
195 struct fuse_inode *fi = get_fuse_inode(inode);
196 struct fuse_file *ff = file->private_data;
198 * file may be written through mmap, so chain it onto the
199 * inodes's write_file list
201 spin_lock(&fc->lock);
202 if (list_empty(&ff->write_entry))
203 list_add(&ff->write_entry, &fi->write_files);
204 spin_unlock(&fc->lock);
207 void fuse_finish_open(struct inode *inode, struct file *file)
209 struct fuse_file *ff = file->private_data;
210 struct fuse_conn *fc = get_fuse_conn(inode);
212 if (ff->open_flags & FOPEN_DIRECT_IO)
213 file->f_op = &fuse_direct_io_file_operations;
214 if (!(ff->open_flags & FOPEN_KEEP_CACHE))
215 invalidate_inode_pages2(inode->i_mapping);
216 if (ff->open_flags & FOPEN_NONSEEKABLE)
217 nonseekable_open(inode, file);
218 if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
219 struct fuse_inode *fi = get_fuse_inode(inode);
221 spin_lock(&fc->lock);
222 fi->attr_version = ++fc->attr_version;
223 i_size_write(inode, 0);
224 spin_unlock(&fc->lock);
225 fuse_invalidate_attr(inode);
227 if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
228 fuse_link_write_file(file);
231 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
233 struct fuse_conn *fc = get_fuse_conn(inode);
236 err = generic_file_open(inode, file);
240 err = fuse_do_open(fc, get_node_id(inode), file, isdir);
244 fuse_finish_open(inode, file);
249 static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
251 struct fuse_conn *fc = ff->fc;
252 struct fuse_req *req = ff->reserved_req;
253 struct fuse_release_in *inarg = &req->misc.release.in;
255 spin_lock(&fc->lock);
256 list_del(&ff->write_entry);
257 if (!RB_EMPTY_NODE(&ff->polled_node))
258 rb_erase(&ff->polled_node, &fc->polled_files);
259 spin_unlock(&fc->lock);
261 wake_up_interruptible_all(&ff->poll_wait);
264 inarg->flags = flags;
265 req->in.h.opcode = opcode;
266 req->in.h.nodeid = ff->nodeid;
268 req->in.args[0].size = sizeof(struct fuse_release_in);
269 req->in.args[0].value = inarg;
272 void fuse_release_common(struct file *file, int opcode)
274 struct fuse_file *ff;
275 struct fuse_req *req;
277 ff = file->private_data;
281 req = ff->reserved_req;
282 fuse_prepare_release(ff, file->f_flags, opcode);
285 struct fuse_release_in *inarg = &req->misc.release.in;
286 inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
287 inarg->lock_owner = fuse_lock_owner_id(ff->fc,
290 /* Hold vfsmount and dentry until release is finished */
291 path_get(&file->f_path);
292 req->misc.release.path = file->f_path;
295 * Normally this will send the RELEASE request, however if
296 * some asynchronous READ or WRITE requests are outstanding,
297 * the sending will be delayed.
299 * Make the release synchronous if this is a fuseblk mount,
300 * synchronous RELEASE is allowed (and desirable) in this case
301 * because the server can be trusted not to screw up.
303 fuse_file_put(ff, ff->fc->destroy_req != NULL);
306 static int fuse_open(struct inode *inode, struct file *file)
308 return fuse_open_common(inode, file, false);
311 static int fuse_release(struct inode *inode, struct file *file)
313 struct fuse_conn *fc = get_fuse_conn(inode);
315 /* see fuse_vma_close() for !writeback_cache case */
316 if (fc->writeback_cache)
317 filemap_write_and_wait(file->f_mapping);
319 if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state))
320 fuse_flush_mtime(file, true);
322 fuse_release_common(file, FUSE_RELEASE);
324 /* return value is ignored by VFS */
328 void fuse_sync_release(struct fuse_file *ff, int flags)
330 WARN_ON(atomic_read(&ff->count) > 1);
331 fuse_prepare_release(ff, flags, FUSE_RELEASE);
332 ff->reserved_req->force = 1;
333 ff->reserved_req->background = 0;
334 fuse_request_send(ff->fc, ff->reserved_req);
335 fuse_put_request(ff->fc, ff->reserved_req);
338 EXPORT_SYMBOL_GPL(fuse_sync_release);
341 * Scramble the ID space with XTEA, so that the value of the files_struct
342 * pointer is not exposed to userspace.
344 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
346 u32 *k = fc->scramble_key;
347 u64 v = (unsigned long) id;
353 for (i = 0; i < 32; i++) {
354 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
356 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
359 return (u64) v0 + ((u64) v1 << 32);
363 * Check if any page in a range is under writeback
365 * This is currently done by walking the list of writepage requests
366 * for the inode, which can be pretty inefficient.
368 static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from,
371 struct fuse_conn *fc = get_fuse_conn(inode);
372 struct fuse_inode *fi = get_fuse_inode(inode);
373 struct fuse_req *req;
376 spin_lock(&fc->lock);
377 list_for_each_entry(req, &fi->writepages, writepages_entry) {
380 BUG_ON(req->inode != inode);
381 curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
382 if (idx_from < curr_index + req->num_pages &&
383 curr_index <= idx_to) {
388 spin_unlock(&fc->lock);
393 static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
395 return fuse_range_is_writeback(inode, index, index);
399 * Wait for page writeback to be completed.
401 * Since fuse doesn't rely on the VM writeback tracking, this has to
402 * use some other means.
404 static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
406 struct fuse_inode *fi = get_fuse_inode(inode);
408 wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
413 * Wait for all pending writepages on the inode to finish.
415 * This is currently done by blocking further writes with FUSE_NOWRITE
416 * and waiting for all sent writes to complete.
418 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
419 * could conflict with truncation.
421 static void fuse_sync_writes(struct inode *inode)
423 fuse_set_nowrite(inode);
424 fuse_release_nowrite(inode);
427 static int fuse_flush(struct file *file, fl_owner_t id)
429 struct inode *inode = file_inode(file);
430 struct fuse_conn *fc = get_fuse_conn(inode);
431 struct fuse_file *ff = file->private_data;
432 struct fuse_req *req;
433 struct fuse_flush_in inarg;
436 if (is_bad_inode(inode))
442 err = filemap_write_and_wait(file->f_mapping);
446 mutex_lock(&inode->i_mutex);
447 fuse_sync_writes(inode);
448 mutex_unlock(&inode->i_mutex);
450 req = fuse_get_req_nofail_nopages(fc, file);
451 memset(&inarg, 0, sizeof(inarg));
453 inarg.lock_owner = fuse_lock_owner_id(fc, id);
454 req->in.h.opcode = FUSE_FLUSH;
455 req->in.h.nodeid = get_node_id(inode);
457 req->in.args[0].size = sizeof(inarg);
458 req->in.args[0].value = &inarg;
460 fuse_request_send(fc, req);
461 err = req->out.h.error;
462 fuse_put_request(fc, req);
463 if (err == -ENOSYS) {
470 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
471 int datasync, int isdir)
473 struct inode *inode = file->f_mapping->host;
474 struct fuse_conn *fc = get_fuse_conn(inode);
475 struct fuse_file *ff = file->private_data;
476 struct fuse_req *req;
477 struct fuse_fsync_in inarg;
480 if (is_bad_inode(inode))
483 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
487 if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
490 mutex_lock(&inode->i_mutex);
493 * Start writeback against all dirty pages of the inode, then
494 * wait for all outstanding writes, before sending the FSYNC
497 err = write_inode_now(inode, 0);
501 fuse_sync_writes(inode);
503 if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state)) {
504 int err = fuse_flush_mtime(file, false);
509 req = fuse_get_req_nopages(fc);
515 memset(&inarg, 0, sizeof(inarg));
517 inarg.fsync_flags = datasync ? 1 : 0;
518 req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
519 req->in.h.nodeid = get_node_id(inode);
521 req->in.args[0].size = sizeof(inarg);
522 req->in.args[0].value = &inarg;
523 fuse_request_send(fc, req);
524 err = req->out.h.error;
525 fuse_put_request(fc, req);
526 if (err == -ENOSYS) {
534 mutex_unlock(&inode->i_mutex);
538 static int fuse_fsync(struct file *file, loff_t start, loff_t end,
541 return fuse_fsync_common(file, start, end, datasync, 0);
544 void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
545 size_t count, int opcode)
547 struct fuse_read_in *inarg = &req->misc.read.in;
548 struct fuse_file *ff = file->private_data;
553 inarg->flags = file->f_flags;
554 req->in.h.opcode = opcode;
555 req->in.h.nodeid = ff->nodeid;
557 req->in.args[0].size = sizeof(struct fuse_read_in);
558 req->in.args[0].value = inarg;
560 req->out.numargs = 1;
561 req->out.args[0].size = count;
564 static void fuse_release_user_pages(struct fuse_req *req, int write)
568 for (i = 0; i < req->num_pages; i++) {
569 struct page *page = req->pages[i];
571 set_page_dirty_lock(page);
577 * In case of short read, the caller sets 'pos' to the position of
578 * actual end of fuse request in IO request. Otherwise, if bytes_requested
579 * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.
582 * User requested DIO read of 64K. It was splitted into two 32K fuse requests,
583 * both submitted asynchronously. The first of them was ACKed by userspace as
584 * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The
585 * second request was ACKed as short, e.g. only 1K was read, resulting in
588 * Thus, when all fuse requests are completed, the minimal non-negative 'pos'
589 * will be equal to the length of the longest contiguous fragment of
590 * transferred data starting from the beginning of IO request.
592 static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
596 spin_lock(&io->lock);
598 io->err = io->err ? : err;
599 else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes))
603 spin_unlock(&io->lock);
610 else if (io->bytes >= 0 && io->write)
613 res = io->bytes < 0 ? io->size : io->bytes;
615 if (!is_sync_kiocb(io->iocb)) {
616 struct inode *inode = file_inode(io->iocb->ki_filp);
617 struct fuse_conn *fc = get_fuse_conn(inode);
618 struct fuse_inode *fi = get_fuse_inode(inode);
620 spin_lock(&fc->lock);
621 fi->attr_version = ++fc->attr_version;
622 spin_unlock(&fc->lock);
626 aio_complete(io->iocb, res, 0);
631 static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
633 struct fuse_io_priv *io = req->io;
636 fuse_release_user_pages(req, !io->write);
639 if (req->misc.write.in.size != req->misc.write.out.size)
640 pos = req->misc.write.in.offset - io->offset +
641 req->misc.write.out.size;
643 if (req->misc.read.in.size != req->out.args[0].size)
644 pos = req->misc.read.in.offset - io->offset +
645 req->out.args[0].size;
648 fuse_aio_complete(io, req->out.h.error, pos);
651 static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
652 size_t num_bytes, struct fuse_io_priv *io)
654 spin_lock(&io->lock);
655 io->size += num_bytes;
657 spin_unlock(&io->lock);
660 req->end = fuse_aio_complete_req;
662 __fuse_get_request(req);
663 fuse_request_send_background(fc, req);
668 static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
669 loff_t pos, size_t count, fl_owner_t owner)
671 struct file *file = io->file;
672 struct fuse_file *ff = file->private_data;
673 struct fuse_conn *fc = ff->fc;
675 fuse_read_fill(req, file, pos, count, FUSE_READ);
677 struct fuse_read_in *inarg = &req->misc.read.in;
679 inarg->read_flags |= FUSE_READ_LOCKOWNER;
680 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
684 return fuse_async_req_send(fc, req, count, io);
686 fuse_request_send(fc, req);
687 return req->out.args[0].size;
690 static void fuse_read_update_size(struct inode *inode, loff_t size,
693 struct fuse_conn *fc = get_fuse_conn(inode);
694 struct fuse_inode *fi = get_fuse_inode(inode);
696 spin_lock(&fc->lock);
697 if (attr_ver == fi->attr_version && size < inode->i_size &&
698 !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
699 fi->attr_version = ++fc->attr_version;
700 i_size_write(inode, size);
702 spin_unlock(&fc->lock);
705 static void fuse_short_read(struct fuse_req *req, struct inode *inode,
708 size_t num_read = req->out.args[0].size;
709 struct fuse_conn *fc = get_fuse_conn(inode);
711 if (fc->writeback_cache) {
713 * A hole in a file. Some data after the hole are in page cache,
714 * but have not reached the client fs yet. So, the hole is not
718 int start_idx = num_read >> PAGE_CACHE_SHIFT;
719 size_t off = num_read & (PAGE_CACHE_SIZE - 1);
721 for (i = start_idx; i < req->num_pages; i++) {
722 zero_user_segment(req->pages[i], off, PAGE_CACHE_SIZE);
726 loff_t pos = page_offset(req->pages[0]) + num_read;
727 fuse_read_update_size(inode, pos, attr_ver);
731 static int fuse_do_readpage(struct file *file, struct page *page)
733 struct fuse_io_priv io = { .async = 0, .file = file };
734 struct inode *inode = page->mapping->host;
735 struct fuse_conn *fc = get_fuse_conn(inode);
736 struct fuse_req *req;
738 loff_t pos = page_offset(page);
739 size_t count = PAGE_CACHE_SIZE;
744 * Page writeback can extend beyond the lifetime of the
745 * page-cache page, so make sure we read a properly synced
748 fuse_wait_on_page_writeback(inode, page->index);
750 req = fuse_get_req(fc, 1);
754 attr_ver = fuse_get_attr_version(fc);
756 req->out.page_zeroing = 1;
757 req->out.argpages = 1;
759 req->pages[0] = page;
760 req->page_descs[0].length = count;
761 num_read = fuse_send_read(req, &io, pos, count, NULL);
762 err = req->out.h.error;
766 * Short read means EOF. If file size is larger, truncate it
768 if (num_read < count)
769 fuse_short_read(req, inode, attr_ver);
771 SetPageUptodate(page);
774 fuse_put_request(fc, req);
779 static int fuse_readpage(struct file *file, struct page *page)
781 struct inode *inode = page->mapping->host;
785 if (is_bad_inode(inode))
788 err = fuse_do_readpage(file, page);
789 fuse_invalidate_atime(inode);
795 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
798 size_t count = req->misc.read.in.size;
799 size_t num_read = req->out.args[0].size;
800 struct address_space *mapping = NULL;
802 for (i = 0; mapping == NULL && i < req->num_pages; i++)
803 mapping = req->pages[i]->mapping;
806 struct inode *inode = mapping->host;
809 * Short read means EOF. If file size is larger, truncate it
811 if (!req->out.h.error && num_read < count)
812 fuse_short_read(req, inode, req->misc.read.attr_ver);
814 fuse_invalidate_atime(inode);
817 for (i = 0; i < req->num_pages; i++) {
818 struct page *page = req->pages[i];
819 if (!req->out.h.error)
820 SetPageUptodate(page);
824 page_cache_release(page);
827 fuse_file_put(req->ff, false);
830 static void fuse_send_readpages(struct fuse_req *req, struct file *file)
832 struct fuse_file *ff = file->private_data;
833 struct fuse_conn *fc = ff->fc;
834 loff_t pos = page_offset(req->pages[0]);
835 size_t count = req->num_pages << PAGE_CACHE_SHIFT;
837 req->out.argpages = 1;
838 req->out.page_zeroing = 1;
839 req->out.page_replace = 1;
840 fuse_read_fill(req, file, pos, count, FUSE_READ);
841 req->misc.read.attr_ver = fuse_get_attr_version(fc);
842 if (fc->async_read) {
843 req->ff = fuse_file_get(ff);
844 req->end = fuse_readpages_end;
845 fuse_request_send_background(fc, req);
847 fuse_request_send(fc, req);
848 fuse_readpages_end(fc, req);
849 fuse_put_request(fc, req);
853 struct fuse_fill_data {
854 struct fuse_req *req;
860 static int fuse_readpages_fill(void *_data, struct page *page)
862 struct fuse_fill_data *data = _data;
863 struct fuse_req *req = data->req;
864 struct inode *inode = data->inode;
865 struct fuse_conn *fc = get_fuse_conn(inode);
867 fuse_wait_on_page_writeback(inode, page->index);
869 if (req->num_pages &&
870 (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
871 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
872 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
873 int nr_alloc = min_t(unsigned, data->nr_pages,
874 FUSE_MAX_PAGES_PER_REQ);
875 fuse_send_readpages(req, data->file);
877 req = fuse_get_req_for_background(fc, nr_alloc);
879 req = fuse_get_req(fc, nr_alloc);
888 if (WARN_ON(req->num_pages >= req->max_pages)) {
889 fuse_put_request(fc, req);
893 page_cache_get(page);
894 req->pages[req->num_pages] = page;
895 req->page_descs[req->num_pages].length = PAGE_SIZE;
901 static int fuse_readpages(struct file *file, struct address_space *mapping,
902 struct list_head *pages, unsigned nr_pages)
904 struct inode *inode = mapping->host;
905 struct fuse_conn *fc = get_fuse_conn(inode);
906 struct fuse_fill_data data;
908 int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ);
911 if (is_bad_inode(inode))
917 data.req = fuse_get_req_for_background(fc, nr_alloc);
919 data.req = fuse_get_req(fc, nr_alloc);
920 data.nr_pages = nr_pages;
921 err = PTR_ERR(data.req);
922 if (IS_ERR(data.req))
925 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
927 if (data.req->num_pages)
928 fuse_send_readpages(data.req, file);
930 fuse_put_request(fc, data.req);
936 static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
937 unsigned long nr_segs, loff_t pos)
939 struct inode *inode = iocb->ki_filp->f_mapping->host;
940 struct fuse_conn *fc = get_fuse_conn(inode);
943 * In auto invalidate mode, always update attributes on read.
944 * Otherwise, only update if we attempt to read past EOF (to ensure
945 * i_size is up to date).
947 if (fc->auto_inval_data ||
948 (pos + iov_length(iov, nr_segs) > i_size_read(inode))) {
950 err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
955 return generic_file_aio_read(iocb, iov, nr_segs, pos);
958 static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
959 loff_t pos, size_t count)
961 struct fuse_write_in *inarg = &req->misc.write.in;
962 struct fuse_write_out *outarg = &req->misc.write.out;
967 req->in.h.opcode = FUSE_WRITE;
968 req->in.h.nodeid = ff->nodeid;
970 if (ff->fc->minor < 9)
971 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
973 req->in.args[0].size = sizeof(struct fuse_write_in);
974 req->in.args[0].value = inarg;
975 req->in.args[1].size = count;
976 req->out.numargs = 1;
977 req->out.args[0].size = sizeof(struct fuse_write_out);
978 req->out.args[0].value = outarg;
981 static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
982 loff_t pos, size_t count, fl_owner_t owner)
984 struct file *file = io->file;
985 struct fuse_file *ff = file->private_data;
986 struct fuse_conn *fc = ff->fc;
987 struct fuse_write_in *inarg = &req->misc.write.in;
989 fuse_write_fill(req, ff, pos, count);
990 inarg->flags = file->f_flags;
992 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
993 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
997 return fuse_async_req_send(fc, req, count, io);
999 fuse_request_send(fc, req);
1000 return req->misc.write.out.size;
1003 bool fuse_write_update_size(struct inode *inode, loff_t pos)
1005 struct fuse_conn *fc = get_fuse_conn(inode);
1006 struct fuse_inode *fi = get_fuse_inode(inode);
1009 spin_lock(&fc->lock);
1010 fi->attr_version = ++fc->attr_version;
1011 if (pos > inode->i_size) {
1012 i_size_write(inode, pos);
1015 spin_unlock(&fc->lock);
1020 static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
1021 struct inode *inode, loff_t pos,
1027 struct fuse_io_priv io = { .async = 0, .file = file };
1029 for (i = 0; i < req->num_pages; i++)
1030 fuse_wait_on_page_writeback(inode, req->pages[i]->index);
1032 res = fuse_send_write(req, &io, pos, count, NULL);
1034 offset = req->page_descs[0].offset;
1036 for (i = 0; i < req->num_pages; i++) {
1037 struct page *page = req->pages[i];
1039 if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
1040 SetPageUptodate(page);
1042 if (count > PAGE_CACHE_SIZE - offset)
1043 count -= PAGE_CACHE_SIZE - offset;
1049 page_cache_release(page);
1055 static ssize_t fuse_fill_write_pages(struct fuse_req *req,
1056 struct address_space *mapping,
1057 struct iov_iter *ii, loff_t pos)
1059 struct fuse_conn *fc = get_fuse_conn(mapping->host);
1060 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
1064 req->in.argpages = 1;
1065 req->page_descs[0].offset = offset;
1070 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1071 size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
1072 iov_iter_count(ii));
1074 bytes = min_t(size_t, bytes, fc->max_write - count);
1078 if (iov_iter_fault_in_readable(ii, bytes))
1082 page = grab_cache_page_write_begin(mapping, index, 0);
1086 if (mapping_writably_mapped(mapping))
1087 flush_dcache_page(page);
1089 tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
1090 flush_dcache_page(page);
1092 mark_page_accessed(page);
1096 page_cache_release(page);
1097 bytes = min(bytes, iov_iter_single_seg_count(ii));
1102 req->pages[req->num_pages] = page;
1103 req->page_descs[req->num_pages].length = tmp;
1106 iov_iter_advance(ii, tmp);
1110 if (offset == PAGE_CACHE_SIZE)
1113 if (!fc->big_writes)
1115 } while (iov_iter_count(ii) && count < fc->max_write &&
1116 req->num_pages < req->max_pages && offset == 0);
1118 return count > 0 ? count : err;
1121 static inline unsigned fuse_wr_pages(loff_t pos, size_t len)
1123 return min_t(unsigned,
1124 ((pos + len - 1) >> PAGE_CACHE_SHIFT) -
1125 (pos >> PAGE_CACHE_SHIFT) + 1,
1126 FUSE_MAX_PAGES_PER_REQ);
1129 static ssize_t fuse_perform_write(struct file *file,
1130 struct address_space *mapping,
1131 struct iov_iter *ii, loff_t pos)
1133 struct inode *inode = mapping->host;
1134 struct fuse_conn *fc = get_fuse_conn(inode);
1135 struct fuse_inode *fi = get_fuse_inode(inode);
1139 if (is_bad_inode(inode))
1142 if (inode->i_size < pos + iov_iter_count(ii))
1143 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1146 struct fuse_req *req;
1148 unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii));
1150 req = fuse_get_req(fc, nr_pages);
1156 count = fuse_fill_write_pages(req, mapping, ii, pos);
1162 num_written = fuse_send_write_pages(req, file, inode,
1164 err = req->out.h.error;
1169 /* break out of the loop on short write */
1170 if (num_written != count)
1174 fuse_put_request(fc, req);
1175 } while (!err && iov_iter_count(ii));
1178 fuse_write_update_size(inode, pos);
1180 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1181 fuse_invalidate_attr(inode);
1183 return res > 0 ? res : err;
1186 static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
1187 unsigned long nr_segs, loff_t pos)
1189 struct file *file = iocb->ki_filp;
1190 struct address_space *mapping = file->f_mapping;
1193 ssize_t written = 0;
1194 ssize_t written_buffered = 0;
1195 struct inode *inode = mapping->host;
1200 if (get_fuse_conn(inode)->writeback_cache) {
1201 /* Update size (EOF optimization) and mode (SUID clearing) */
1202 err = fuse_update_attributes(mapping->host, NULL, file, NULL);
1206 return generic_file_aio_write(iocb, iov, nr_segs, pos);
1209 WARN_ON(iocb->ki_pos != pos);
1212 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1217 mutex_lock(&inode->i_mutex);
1219 /* We can write back this queue in page reclaim */
1220 current->backing_dev_info = mapping->backing_dev_info;
1222 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1229 err = file_remove_suid(file);
1233 err = file_update_time(file);
1237 if (file->f_flags & O_DIRECT) {
1238 written = generic_file_direct_write(iocb, iov, &nr_segs, pos,
1240 if (written < 0 || written == count)
1246 iov_iter_init(&i, iov, nr_segs, count, written);
1247 written_buffered = fuse_perform_write(file, mapping, &i, pos);
1248 if (written_buffered < 0) {
1249 err = written_buffered;
1252 endbyte = pos + written_buffered - 1;
1254 err = filemap_write_and_wait_range(file->f_mapping, pos,
1259 invalidate_mapping_pages(file->f_mapping,
1260 pos >> PAGE_CACHE_SHIFT,
1261 endbyte >> PAGE_CACHE_SHIFT);
1263 written += written_buffered;
1264 iocb->ki_pos = pos + written_buffered;
1266 iov_iter_init(&i, iov, nr_segs, count, 0);
1267 written = fuse_perform_write(file, mapping, &i, pos);
1269 iocb->ki_pos = pos + written;
1272 current->backing_dev_info = NULL;
1273 mutex_unlock(&inode->i_mutex);
1275 return written ? written : err;
1278 static inline void fuse_page_descs_length_init(struct fuse_req *req,
1279 unsigned index, unsigned nr_pages)
1283 for (i = index; i < index + nr_pages; i++)
1284 req->page_descs[i].length = PAGE_SIZE -
1285 req->page_descs[i].offset;
1288 static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
1290 return (unsigned long)ii->iov->iov_base + ii->iov_offset;
1293 static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
1296 return min(iov_iter_single_seg_count(ii), max_size);
1299 static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
1300 size_t *nbytesp, int write)
1302 size_t nbytes = 0; /* # bytes already packed in req */
1304 /* Special case for kernel I/O: can copy directly into the buffer */
1305 if (segment_eq(get_fs(), KERNEL_DS)) {
1306 unsigned long user_addr = fuse_get_user_addr(ii);
1307 size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
1310 req->in.args[1].value = (void *) user_addr;
1312 req->out.args[0].value = (void *) user_addr;
1314 iov_iter_advance(ii, frag_size);
1315 *nbytesp = frag_size;
1319 while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
1321 unsigned long user_addr = fuse_get_user_addr(ii);
1322 unsigned offset = user_addr & ~PAGE_MASK;
1323 size_t frag_size = fuse_get_frag_size(ii, *nbytesp - nbytes);
1326 unsigned n = req->max_pages - req->num_pages;
1327 frag_size = min_t(size_t, frag_size, n << PAGE_SHIFT);
1329 npages = (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1330 npages = clamp(npages, 1U, n);
1332 ret = get_user_pages_fast(user_addr, npages, !write,
1333 &req->pages[req->num_pages]);
1338 frag_size = min_t(size_t, frag_size,
1339 (npages << PAGE_SHIFT) - offset);
1340 iov_iter_advance(ii, frag_size);
1342 req->page_descs[req->num_pages].offset = offset;
1343 fuse_page_descs_length_init(req, req->num_pages, npages);
1345 req->num_pages += npages;
1346 req->page_descs[req->num_pages - 1].length -=
1347 (npages << PAGE_SHIFT) - offset - frag_size;
1349 nbytes += frag_size;
1353 req->in.argpages = 1;
1355 req->out.argpages = 1;
1362 static inline int fuse_iter_npages(const struct iov_iter *ii_p)
1364 struct iov_iter ii = *ii_p;
1367 while (iov_iter_count(&ii) && npages < FUSE_MAX_PAGES_PER_REQ) {
1368 unsigned long user_addr = fuse_get_user_addr(&ii);
1369 unsigned offset = user_addr & ~PAGE_MASK;
1370 size_t frag_size = iov_iter_single_seg_count(&ii);
1372 npages += (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1373 iov_iter_advance(&ii, frag_size);
1376 return min(npages, FUSE_MAX_PAGES_PER_REQ);
1379 ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
1380 unsigned long nr_segs, size_t count, loff_t *ppos,
1383 int write = flags & FUSE_DIO_WRITE;
1384 int cuse = flags & FUSE_DIO_CUSE;
1385 struct file *file = io->file;
1386 struct inode *inode = file->f_mapping->host;
1387 struct fuse_file *ff = file->private_data;
1388 struct fuse_conn *fc = ff->fc;
1389 size_t nmax = write ? fc->max_write : fc->max_read;
1391 pgoff_t idx_from = pos >> PAGE_CACHE_SHIFT;
1392 pgoff_t idx_to = (pos + count - 1) >> PAGE_CACHE_SHIFT;
1394 struct fuse_req *req;
1397 iov_iter_init(&ii, iov, nr_segs, count, 0);
1400 req = fuse_get_req_for_background(fc, fuse_iter_npages(&ii));
1402 req = fuse_get_req(fc, fuse_iter_npages(&ii));
1404 return PTR_ERR(req);
1406 if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
1408 mutex_lock(&inode->i_mutex);
1409 fuse_sync_writes(inode);
1411 mutex_unlock(&inode->i_mutex);
1416 fl_owner_t owner = current->files;
1417 size_t nbytes = min(count, nmax);
1418 int err = fuse_get_user_pages(req, &ii, &nbytes, write);
1425 nres = fuse_send_write(req, io, pos, nbytes, owner);
1427 nres = fuse_send_read(req, io, pos, nbytes, owner);
1430 fuse_release_user_pages(req, !write);
1431 if (req->out.h.error) {
1433 res = req->out.h.error;
1435 } else if (nres > nbytes) {
1445 fuse_put_request(fc, req);
1447 req = fuse_get_req_for_background(fc,
1448 fuse_iter_npages(&ii));
1450 req = fuse_get_req(fc, fuse_iter_npages(&ii));
1456 fuse_put_request(fc, req);
1462 EXPORT_SYMBOL_GPL(fuse_direct_io);
1464 static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
1465 const struct iovec *iov,
1466 unsigned long nr_segs, loff_t *ppos,
1470 struct file *file = io->file;
1471 struct inode *inode = file_inode(file);
1473 if (is_bad_inode(inode))
1476 res = fuse_direct_io(io, iov, nr_segs, count, ppos, 0);
1478 fuse_invalidate_attr(inode);
1483 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
1484 size_t count, loff_t *ppos)
1486 struct fuse_io_priv io = { .async = 0, .file = file };
1487 struct iovec iov = { .iov_base = buf, .iov_len = count };
1488 return __fuse_direct_read(&io, &iov, 1, ppos, count);
1491 static ssize_t __fuse_direct_write(struct fuse_io_priv *io,
1492 const struct iovec *iov,
1493 unsigned long nr_segs, loff_t *ppos)
1495 struct file *file = io->file;
1496 struct inode *inode = file_inode(file);
1497 size_t count = iov_length(iov, nr_segs);
1500 res = generic_write_checks(file, ppos, &count, 0);
1502 res = fuse_direct_io(io, iov, nr_segs, count, ppos,
1505 fuse_invalidate_attr(inode);
1510 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
1511 size_t count, loff_t *ppos)
1513 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
1514 struct inode *inode = file_inode(file);
1516 struct fuse_io_priv io = { .async = 0, .file = file };
1518 if (is_bad_inode(inode))
1521 /* Don't allow parallel writes to the same file */
1522 mutex_lock(&inode->i_mutex);
1523 res = __fuse_direct_write(&io, &iov, 1, ppos);
1525 fuse_write_update_size(inode, *ppos);
1526 mutex_unlock(&inode->i_mutex);
1531 static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
1535 for (i = 0; i < req->num_pages; i++)
1536 __free_page(req->pages[i]);
1539 fuse_file_put(req->ff, false);
1542 static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
1544 struct inode *inode = req->inode;
1545 struct fuse_inode *fi = get_fuse_inode(inode);
1546 struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
1549 list_del(&req->writepages_entry);
1550 for (i = 0; i < req->num_pages; i++) {
1551 dec_bdi_stat(bdi, BDI_WRITEBACK);
1552 dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP);
1553 bdi_writeout_inc(bdi);
1555 wake_up(&fi->page_waitq);
1558 /* Called under fc->lock, may release and reacquire it */
1559 static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req,
1561 __releases(fc->lock)
1562 __acquires(fc->lock)
1564 struct fuse_inode *fi = get_fuse_inode(req->inode);
1565 struct fuse_write_in *inarg = &req->misc.write.in;
1566 __u64 data_size = req->num_pages * PAGE_CACHE_SIZE;
1571 if (inarg->offset + data_size <= size) {
1572 inarg->size = data_size;
1573 } else if (inarg->offset < size) {
1574 inarg->size = size - inarg->offset;
1576 /* Got truncated off completely */
1580 req->in.args[1].size = inarg->size;
1582 fuse_request_send_background_locked(fc, req);
1586 fuse_writepage_finish(fc, req);
1587 spin_unlock(&fc->lock);
1588 fuse_writepage_free(fc, req);
1589 fuse_put_request(fc, req);
1590 spin_lock(&fc->lock);
1594 * If fi->writectr is positive (no truncate or fsync going on) send
1595 * all queued writepage requests.
1597 * Called with fc->lock
1599 void fuse_flush_writepages(struct inode *inode)
1600 __releases(fc->lock)
1601 __acquires(fc->lock)
1603 struct fuse_conn *fc = get_fuse_conn(inode);
1604 struct fuse_inode *fi = get_fuse_inode(inode);
1605 size_t crop = i_size_read(inode);
1606 struct fuse_req *req;
1608 while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
1609 req = list_entry(fi->queued_writes.next, struct fuse_req, list);
1610 list_del_init(&req->list);
1611 fuse_send_writepage(fc, req, crop);
1615 static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
1617 struct inode *inode = req->inode;
1618 struct fuse_inode *fi = get_fuse_inode(inode);
1620 mapping_set_error(inode->i_mapping, req->out.h.error);
1621 spin_lock(&fc->lock);
1622 while (req->misc.write.next) {
1623 struct fuse_conn *fc = get_fuse_conn(inode);
1624 struct fuse_write_in *inarg = &req->misc.write.in;
1625 struct fuse_req *next = req->misc.write.next;
1626 req->misc.write.next = next->misc.write.next;
1627 next->misc.write.next = NULL;
1628 next->ff = fuse_file_get(req->ff);
1629 list_add(&next->writepages_entry, &fi->writepages);
1632 * Skip fuse_flush_writepages() to make it easy to crop requests
1633 * based on primary request size.
1635 * 1st case (trivial): there are no concurrent activities using
1636 * fuse_set/release_nowrite. Then we're on safe side because
1637 * fuse_flush_writepages() would call fuse_send_writepage()
1640 * 2nd case: someone called fuse_set_nowrite and it is waiting
1641 * now for completion of all in-flight requests. This happens
1642 * rarely and no more than once per page, so this should be
1645 * 3rd case: someone (e.g. fuse_do_setattr()) is in the middle
1646 * of fuse_set_nowrite..fuse_release_nowrite section. The fact
1647 * that fuse_set_nowrite returned implies that all in-flight
1648 * requests were completed along with all of their secondary
1649 * requests. Further primary requests are blocked by negative
1650 * writectr. Hence there cannot be any in-flight requests and
1651 * no invocations of fuse_writepage_end() while we're in
1652 * fuse_set_nowrite..fuse_release_nowrite section.
1654 fuse_send_writepage(fc, next, inarg->offset + inarg->size);
1657 fuse_writepage_finish(fc, req);
1658 spin_unlock(&fc->lock);
1659 fuse_writepage_free(fc, req);
1662 static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc,
1663 struct fuse_inode *fi)
1665 struct fuse_file *ff = NULL;
1667 spin_lock(&fc->lock);
1668 if (!WARN_ON(list_empty(&fi->write_files))) {
1669 ff = list_entry(fi->write_files.next, struct fuse_file,
1673 spin_unlock(&fc->lock);
1678 static int fuse_writepage_locked(struct page *page)
1680 struct address_space *mapping = page->mapping;
1681 struct inode *inode = mapping->host;
1682 struct fuse_conn *fc = get_fuse_conn(inode);
1683 struct fuse_inode *fi = get_fuse_inode(inode);
1684 struct fuse_req *req;
1685 struct page *tmp_page;
1686 int error = -ENOMEM;
1688 set_page_writeback(page);
1690 req = fuse_request_alloc_nofs(1);
1694 req->background = 1; /* writeback always goes to bg_queue */
1695 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1700 req->ff = fuse_write_file_get(fc, fi);
1704 fuse_write_fill(req, req->ff, page_offset(page), 0);
1706 copy_highpage(tmp_page, page);
1707 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1708 req->misc.write.next = NULL;
1709 req->in.argpages = 1;
1711 req->pages[0] = tmp_page;
1712 req->page_descs[0].offset = 0;
1713 req->page_descs[0].length = PAGE_SIZE;
1714 req->end = fuse_writepage_end;
1717 inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
1718 inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
1720 spin_lock(&fc->lock);
1721 list_add(&req->writepages_entry, &fi->writepages);
1722 list_add_tail(&req->list, &fi->queued_writes);
1723 fuse_flush_writepages(inode);
1724 spin_unlock(&fc->lock);
1726 end_page_writeback(page);
1731 fuse_request_free(req);
1733 end_page_writeback(page);
1737 static int fuse_writepage(struct page *page, struct writeback_control *wbc)
1741 if (fuse_page_is_writeback(page->mapping->host, page->index)) {
1743 * ->writepages() should be called for sync() and friends. We
1744 * should only get here on direct reclaim and then we are
1745 * allowed to skip a page which is already in flight
1747 WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
1749 redirty_page_for_writepage(wbc, page);
1753 err = fuse_writepage_locked(page);
1759 struct fuse_fill_wb_data {
1760 struct fuse_req *req;
1761 struct fuse_file *ff;
1762 struct inode *inode;
1763 struct page **orig_pages;
1766 static void fuse_writepages_send(struct fuse_fill_wb_data *data)
1768 struct fuse_req *req = data->req;
1769 struct inode *inode = data->inode;
1770 struct fuse_conn *fc = get_fuse_conn(inode);
1771 struct fuse_inode *fi = get_fuse_inode(inode);
1772 int num_pages = req->num_pages;
1775 req->ff = fuse_file_get(data->ff);
1776 spin_lock(&fc->lock);
1777 list_add_tail(&req->list, &fi->queued_writes);
1778 fuse_flush_writepages(inode);
1779 spin_unlock(&fc->lock);
1781 for (i = 0; i < num_pages; i++)
1782 end_page_writeback(data->orig_pages[i]);
1785 static bool fuse_writepage_in_flight(struct fuse_req *new_req,
1788 struct fuse_conn *fc = get_fuse_conn(new_req->inode);
1789 struct fuse_inode *fi = get_fuse_inode(new_req->inode);
1790 struct fuse_req *tmp;
1791 struct fuse_req *old_req;
1795 BUG_ON(new_req->num_pages != 0);
1797 spin_lock(&fc->lock);
1798 list_del(&new_req->writepages_entry);
1799 list_for_each_entry(old_req, &fi->writepages, writepages_entry) {
1800 BUG_ON(old_req->inode != new_req->inode);
1801 curr_index = old_req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
1802 if (curr_index <= page->index &&
1803 page->index < curr_index + old_req->num_pages) {
1809 list_add(&new_req->writepages_entry, &fi->writepages);
1813 new_req->num_pages = 1;
1814 for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) {
1815 BUG_ON(tmp->inode != new_req->inode);
1816 curr_index = tmp->misc.write.in.offset >> PAGE_CACHE_SHIFT;
1817 if (tmp->num_pages == 1 &&
1818 curr_index == page->index) {
1823 if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT ||
1824 old_req->state == FUSE_REQ_PENDING)) {
1825 struct backing_dev_info *bdi = page->mapping->backing_dev_info;
1827 copy_highpage(old_req->pages[0], page);
1828 spin_unlock(&fc->lock);
1830 dec_bdi_stat(bdi, BDI_WRITEBACK);
1831 dec_zone_page_state(page, NR_WRITEBACK_TEMP);
1832 bdi_writeout_inc(bdi);
1833 fuse_writepage_free(fc, new_req);
1834 fuse_request_free(new_req);
1837 new_req->misc.write.next = old_req->misc.write.next;
1838 old_req->misc.write.next = new_req;
1841 spin_unlock(&fc->lock);
1846 static int fuse_writepages_fill(struct page *page,
1847 struct writeback_control *wbc, void *_data)
1849 struct fuse_fill_wb_data *data = _data;
1850 struct fuse_req *req = data->req;
1851 struct inode *inode = data->inode;
1852 struct fuse_conn *fc = get_fuse_conn(inode);
1853 struct page *tmp_page;
1859 data->ff = fuse_write_file_get(fc, get_fuse_inode(inode));
1865 * Being under writeback is unlikely but possible. For example direct
1866 * read to an mmaped fuse file will set the page dirty twice; once when
1867 * the pages are faulted with get_user_pages(), and then after the read
1870 is_writeback = fuse_page_is_writeback(inode, page->index);
1872 if (req && req->num_pages &&
1873 (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
1874 (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_write ||
1875 data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) {
1876 fuse_writepages_send(data);
1880 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1885 * The page must not be redirtied until the writeout is completed
1886 * (i.e. userspace has sent a reply to the write request). Otherwise
1887 * there could be more than one temporary page instance for each real
1890 * This is ensured by holding the page lock in page_mkwrite() while
1891 * checking fuse_page_is_writeback(). We already hold the page lock
1892 * since clear_page_dirty_for_io() and keep it held until we add the
1893 * request to the fi->writepages list and increment req->num_pages.
1894 * After this fuse_page_is_writeback() will indicate that the page is
1895 * under writeback, so we can release the page lock.
1897 if (data->req == NULL) {
1898 struct fuse_inode *fi = get_fuse_inode(inode);
1901 req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ);
1903 __free_page(tmp_page);
1907 fuse_write_fill(req, data->ff, page_offset(page), 0);
1908 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1909 req->misc.write.next = NULL;
1910 req->in.argpages = 1;
1911 req->background = 1;
1913 req->end = fuse_writepage_end;
1916 spin_lock(&fc->lock);
1917 list_add(&req->writepages_entry, &fi->writepages);
1918 spin_unlock(&fc->lock);
1922 set_page_writeback(page);
1924 copy_highpage(tmp_page, page);
1925 req->pages[req->num_pages] = tmp_page;
1926 req->page_descs[req->num_pages].offset = 0;
1927 req->page_descs[req->num_pages].length = PAGE_SIZE;
1929 inc_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK);
1930 inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
1933 if (is_writeback && fuse_writepage_in_flight(req, page)) {
1934 end_page_writeback(page);
1938 data->orig_pages[req->num_pages] = page;
1941 * Protected by fc->lock against concurrent access by
1942 * fuse_page_is_writeback().
1944 spin_lock(&fc->lock);
1946 spin_unlock(&fc->lock);
1954 static int fuse_writepages(struct address_space *mapping,
1955 struct writeback_control *wbc)
1957 struct inode *inode = mapping->host;
1958 struct fuse_fill_wb_data data;
1962 if (is_bad_inode(inode))
1970 data.orig_pages = kzalloc(sizeof(struct page *) *
1971 FUSE_MAX_PAGES_PER_REQ,
1973 if (!data.orig_pages)
1976 err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data);
1978 /* Ignore errors if we can write at least one page */
1979 BUG_ON(!data.req->num_pages);
1980 fuse_writepages_send(&data);
1984 fuse_file_put(data.ff, false);
1986 kfree(data.orig_pages);
1992 * It's worthy to make sure that space is reserved on disk for the write,
1993 * but how to implement it without killing performance need more thinking.
1995 static int fuse_write_begin(struct file *file, struct address_space *mapping,
1996 loff_t pos, unsigned len, unsigned flags,
1997 struct page **pagep, void **fsdata)
1999 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
2000 struct fuse_conn *fc = get_fuse_conn(file->f_dentry->d_inode);
2005 WARN_ON(!fc->writeback_cache);
2007 page = grab_cache_page_write_begin(mapping, index, flags);
2011 fuse_wait_on_page_writeback(mapping->host, page->index);
2013 if (PageUptodate(page) || len == PAGE_CACHE_SIZE)
2016 * Check if the start this page comes after the end of file, in which
2017 * case the readpage can be optimized away.
2019 fsize = i_size_read(mapping->host);
2020 if (fsize <= (pos & PAGE_CACHE_MASK)) {
2021 size_t off = pos & ~PAGE_CACHE_MASK;
2023 zero_user_segment(page, 0, off);
2026 err = fuse_do_readpage(file, page);
2035 page_cache_release(page);
2040 static int fuse_write_end(struct file *file, struct address_space *mapping,
2041 loff_t pos, unsigned len, unsigned copied,
2042 struct page *page, void *fsdata)
2044 struct inode *inode = page->mapping->host;
2046 if (!PageUptodate(page)) {
2047 /* Zero any unwritten bytes at the end of the page */
2048 size_t endoff = (pos + copied) & ~PAGE_CACHE_MASK;
2050 zero_user_segment(page, endoff, PAGE_CACHE_SIZE);
2051 SetPageUptodate(page);
2054 fuse_write_update_size(inode, pos + copied);
2055 set_page_dirty(page);
2057 page_cache_release(page);
2062 static int fuse_launder_page(struct page *page)
2065 if (clear_page_dirty_for_io(page)) {
2066 struct inode *inode = page->mapping->host;
2067 err = fuse_writepage_locked(page);
2069 fuse_wait_on_page_writeback(inode, page->index);
2075 * Write back dirty pages now, because there may not be any suitable
2078 static void fuse_vma_close(struct vm_area_struct *vma)
2080 filemap_write_and_wait(vma->vm_file->f_mapping);
2084 * Wait for writeback against this page to complete before allowing it
2085 * to be marked dirty again, and hence written back again, possibly
2086 * before the previous writepage completed.
2088 * Block here, instead of in ->writepage(), so that the userspace fs
2089 * can only block processes actually operating on the filesystem.
2091 * Otherwise unprivileged userspace fs would be able to block
2096 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
2098 static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
2100 struct page *page = vmf->page;
2101 struct inode *inode = file_inode(vma->vm_file);
2103 file_update_time(vma->vm_file);
2105 if (page->mapping != inode->i_mapping) {
2107 return VM_FAULT_NOPAGE;
2110 fuse_wait_on_page_writeback(inode, page->index);
2111 return VM_FAULT_LOCKED;
2114 static const struct vm_operations_struct fuse_file_vm_ops = {
2115 .close = fuse_vma_close,
2116 .fault = filemap_fault,
2117 .map_pages = filemap_map_pages,
2118 .page_mkwrite = fuse_page_mkwrite,
2119 .remap_pages = generic_file_remap_pages,
2122 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
2124 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
2125 fuse_link_write_file(file);
2127 file_accessed(file);
2128 vma->vm_ops = &fuse_file_vm_ops;
2132 static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
2134 /* Can't provide the coherency needed for MAP_SHARED */
2135 if (vma->vm_flags & VM_MAYSHARE)
2138 invalidate_inode_pages2(file->f_mapping);
2140 return generic_file_mmap(file, vma);
2143 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
2144 struct file_lock *fl)
2146 switch (ffl->type) {
2152 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
2153 ffl->end < ffl->start)
2156 fl->fl_start = ffl->start;
2157 fl->fl_end = ffl->end;
2158 fl->fl_pid = ffl->pid;
2164 fl->fl_type = ffl->type;
2168 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
2169 const struct file_lock *fl, int opcode, pid_t pid,
2172 struct inode *inode = file_inode(file);
2173 struct fuse_conn *fc = get_fuse_conn(inode);
2174 struct fuse_file *ff = file->private_data;
2175 struct fuse_lk_in *arg = &req->misc.lk_in;
2178 arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
2179 arg->lk.start = fl->fl_start;
2180 arg->lk.end = fl->fl_end;
2181 arg->lk.type = fl->fl_type;
2184 arg->lk_flags |= FUSE_LK_FLOCK;
2185 req->in.h.opcode = opcode;
2186 req->in.h.nodeid = get_node_id(inode);
2187 req->in.numargs = 1;
2188 req->in.args[0].size = sizeof(*arg);
2189 req->in.args[0].value = arg;
2192 static int fuse_getlk(struct file *file, struct file_lock *fl)
2194 struct inode *inode = file_inode(file);
2195 struct fuse_conn *fc = get_fuse_conn(inode);
2196 struct fuse_req *req;
2197 struct fuse_lk_out outarg;
2200 req = fuse_get_req_nopages(fc);
2202 return PTR_ERR(req);
2204 fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
2205 req->out.numargs = 1;
2206 req->out.args[0].size = sizeof(outarg);
2207 req->out.args[0].value = &outarg;
2208 fuse_request_send(fc, req);
2209 err = req->out.h.error;
2210 fuse_put_request(fc, req);
2212 err = convert_fuse_file_lock(&outarg.lk, fl);
2217 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
2219 struct inode *inode = file_inode(file);
2220 struct fuse_conn *fc = get_fuse_conn(inode);
2221 struct fuse_req *req;
2222 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
2223 pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
2226 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
2227 /* NLM needs asynchronous locks, which we don't support yet */
2231 /* Unlock on close is handled by the flush method */
2232 if (fl->fl_flags & FL_CLOSE)
2235 req = fuse_get_req_nopages(fc);
2237 return PTR_ERR(req);
2239 fuse_lk_fill(req, file, fl, opcode, pid, flock);
2240 fuse_request_send(fc, req);
2241 err = req->out.h.error;
2242 /* locking is restartable */
2245 fuse_put_request(fc, req);
2249 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
2251 struct inode *inode = file_inode(file);
2252 struct fuse_conn *fc = get_fuse_conn(inode);
2255 if (cmd == F_CANCELLK) {
2257 } else if (cmd == F_GETLK) {
2259 posix_test_lock(file, fl);
2262 err = fuse_getlk(file, fl);
2265 err = posix_lock_file(file, fl, NULL);
2267 err = fuse_setlk(file, fl, 0);
2272 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
2274 struct inode *inode = file_inode(file);
2275 struct fuse_conn *fc = get_fuse_conn(inode);
2279 err = flock_lock_file_wait(file, fl);
2281 struct fuse_file *ff = file->private_data;
2283 /* emulate flock with POSIX locks */
2284 fl->fl_owner = (fl_owner_t) file;
2286 err = fuse_setlk(file, fl, 1);
2292 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
2294 struct inode *inode = mapping->host;
2295 struct fuse_conn *fc = get_fuse_conn(inode);
2296 struct fuse_req *req;
2297 struct fuse_bmap_in inarg;
2298 struct fuse_bmap_out outarg;
2301 if (!inode->i_sb->s_bdev || fc->no_bmap)
2304 req = fuse_get_req_nopages(fc);
2308 memset(&inarg, 0, sizeof(inarg));
2309 inarg.block = block;
2310 inarg.blocksize = inode->i_sb->s_blocksize;
2311 req->in.h.opcode = FUSE_BMAP;
2312 req->in.h.nodeid = get_node_id(inode);
2313 req->in.numargs = 1;
2314 req->in.args[0].size = sizeof(inarg);
2315 req->in.args[0].value = &inarg;
2316 req->out.numargs = 1;
2317 req->out.args[0].size = sizeof(outarg);
2318 req->out.args[0].value = &outarg;
2319 fuse_request_send(fc, req);
2320 err = req->out.h.error;
2321 fuse_put_request(fc, req);
2325 return err ? 0 : outarg.block;
2328 static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
2331 struct inode *inode = file_inode(file);
2333 /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
2334 if (whence == SEEK_CUR || whence == SEEK_SET)
2335 return generic_file_llseek(file, offset, whence);
2337 mutex_lock(&inode->i_mutex);
2338 retval = fuse_update_attributes(inode, NULL, file, NULL);
2340 retval = generic_file_llseek(file, offset, whence);
2341 mutex_unlock(&inode->i_mutex);
2346 static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
2347 unsigned int nr_segs, size_t bytes, bool to_user)
2355 iov_iter_init(&ii, iov, nr_segs, bytes, 0);
2357 while (iov_iter_count(&ii)) {
2358 struct page *page = pages[page_idx++];
2359 size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
2365 char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
2366 size_t iov_len = ii.iov->iov_len - ii.iov_offset;
2367 size_t copy = min(todo, iov_len);
2371 left = copy_from_user(kaddr, uaddr, copy);
2373 left = copy_to_user(uaddr, kaddr, copy);
2378 iov_iter_advance(&ii, copy);
2390 * CUSE servers compiled on 32bit broke on 64bit kernels because the
2391 * ABI was defined to be 'struct iovec' which is different on 32bit
2392 * and 64bit. Fortunately we can determine which structure the server
2393 * used from the size of the reply.
2395 static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
2396 size_t transferred, unsigned count,
2399 #ifdef CONFIG_COMPAT
2400 if (count * sizeof(struct compat_iovec) == transferred) {
2401 struct compat_iovec *ciov = src;
2405 * With this interface a 32bit server cannot support
2406 * non-compat (i.e. ones coming from 64bit apps) ioctl
2412 for (i = 0; i < count; i++) {
2413 dst[i].iov_base = compat_ptr(ciov[i].iov_base);
2414 dst[i].iov_len = ciov[i].iov_len;
2420 if (count * sizeof(struct iovec) != transferred)
2423 memcpy(dst, src, transferred);
2427 /* Make sure iov_length() won't overflow */
2428 static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
2431 u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
2433 for (n = 0; n < count; n++, iov++) {
2434 if (iov->iov_len > (size_t) max)
2436 max -= iov->iov_len;
2441 static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
2442 void *src, size_t transferred, unsigned count,
2446 struct fuse_ioctl_iovec *fiov = src;
2448 if (fc->minor < 16) {
2449 return fuse_copy_ioctl_iovec_old(dst, src, transferred,
2453 if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
2456 for (i = 0; i < count; i++) {
2457 /* Did the server supply an inappropriate value? */
2458 if (fiov[i].base != (unsigned long) fiov[i].base ||
2459 fiov[i].len != (unsigned long) fiov[i].len)
2462 dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
2463 dst[i].iov_len = (size_t) fiov[i].len;
2465 #ifdef CONFIG_COMPAT
2467 (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
2468 (compat_size_t) dst[i].iov_len != fiov[i].len))
2478 * For ioctls, there is no generic way to determine how much memory
2479 * needs to be read and/or written. Furthermore, ioctls are allowed
2480 * to dereference the passed pointer, so the parameter requires deep
2481 * copying but FUSE has no idea whatsoever about what to copy in or
2484 * This is solved by allowing FUSE server to retry ioctl with
2485 * necessary in/out iovecs. Let's assume the ioctl implementation
2486 * needs to read in the following structure.
2493 * On the first callout to FUSE server, inarg->in_size and
2494 * inarg->out_size will be NULL; then, the server completes the ioctl
2495 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
2496 * the actual iov array to
2498 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
2500 * which tells FUSE to copy in the requested area and retry the ioctl.
2501 * On the second round, the server has access to the structure and
2502 * from that it can tell what to look for next, so on the invocation,
2503 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
2505 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
2506 * { .iov_base = a.buf, .iov_len = a.buflen } }
2508 * FUSE will copy both struct a and the pointed buffer from the
2509 * process doing the ioctl and retry ioctl with both struct a and the
2512 * This time, FUSE server has everything it needs and completes ioctl
2513 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
2515 * Copying data out works the same way.
2517 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
2518 * automatically initializes in and out iovs by decoding @cmd with
2519 * _IOC_* macros and the server is not allowed to request RETRY. This
2520 * limits ioctl data transfers to well-formed ioctls and is the forced
2521 * behavior for all FUSE servers.
2523 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
2526 struct fuse_file *ff = file->private_data;
2527 struct fuse_conn *fc = ff->fc;
2528 struct fuse_ioctl_in inarg = {
2534 struct fuse_ioctl_out outarg;
2535 struct fuse_req *req = NULL;
2536 struct page **pages = NULL;
2537 struct iovec *iov_page = NULL;
2538 struct iovec *in_iov = NULL, *out_iov = NULL;
2539 unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
2540 size_t in_size, out_size, transferred;
2543 #if BITS_PER_LONG == 32
2544 inarg.flags |= FUSE_IOCTL_32BIT;
2546 if (flags & FUSE_IOCTL_COMPAT)
2547 inarg.flags |= FUSE_IOCTL_32BIT;
2550 /* assume all the iovs returned by client always fits in a page */
2551 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
2554 pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL);
2555 iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
2556 if (!pages || !iov_page)
2560 * If restricted, initialize IO parameters as encoded in @cmd.
2561 * RETRY from server is not allowed.
2563 if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
2564 struct iovec *iov = iov_page;
2566 iov->iov_base = (void __user *)arg;
2567 iov->iov_len = _IOC_SIZE(cmd);
2569 if (_IOC_DIR(cmd) & _IOC_WRITE) {
2574 if (_IOC_DIR(cmd) & _IOC_READ) {
2581 inarg.in_size = in_size = iov_length(in_iov, in_iovs);
2582 inarg.out_size = out_size = iov_length(out_iov, out_iovs);
2585 * Out data can be used either for actual out data or iovs,
2586 * make sure there always is at least one page.
2588 out_size = max_t(size_t, out_size, PAGE_SIZE);
2589 max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
2591 /* make sure there are enough buffer pages and init request with them */
2593 if (max_pages > FUSE_MAX_PAGES_PER_REQ)
2595 while (num_pages < max_pages) {
2596 pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
2597 if (!pages[num_pages])
2602 req = fuse_get_req(fc, num_pages);
2608 memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
2609 req->num_pages = num_pages;
2610 fuse_page_descs_length_init(req, 0, req->num_pages);
2612 /* okay, let's send it to the client */
2613 req->in.h.opcode = FUSE_IOCTL;
2614 req->in.h.nodeid = ff->nodeid;
2615 req->in.numargs = 1;
2616 req->in.args[0].size = sizeof(inarg);
2617 req->in.args[0].value = &inarg;
2620 req->in.args[1].size = in_size;
2621 req->in.argpages = 1;
2623 err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
2629 req->out.numargs = 2;
2630 req->out.args[0].size = sizeof(outarg);
2631 req->out.args[0].value = &outarg;
2632 req->out.args[1].size = out_size;
2633 req->out.argpages = 1;
2634 req->out.argvar = 1;
2636 fuse_request_send(fc, req);
2637 err = req->out.h.error;
2638 transferred = req->out.args[1].size;
2639 fuse_put_request(fc, req);
2644 /* did it ask for retry? */
2645 if (outarg.flags & FUSE_IOCTL_RETRY) {
2648 /* no retry if in restricted mode */
2650 if (!(flags & FUSE_IOCTL_UNRESTRICTED))
2653 in_iovs = outarg.in_iovs;
2654 out_iovs = outarg.out_iovs;
2657 * Make sure things are in boundary, separate checks
2658 * are to protect against overflow.
2661 if (in_iovs > FUSE_IOCTL_MAX_IOV ||
2662 out_iovs > FUSE_IOCTL_MAX_IOV ||
2663 in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
2666 vaddr = kmap_atomic(pages[0]);
2667 err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
2668 transferred, in_iovs + out_iovs,
2669 (flags & FUSE_IOCTL_COMPAT) != 0);
2670 kunmap_atomic(vaddr);
2675 out_iov = in_iov + in_iovs;
2677 err = fuse_verify_ioctl_iov(in_iov, in_iovs);
2681 err = fuse_verify_ioctl_iov(out_iov, out_iovs);
2689 if (transferred > inarg.out_size)
2692 err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
2695 fuse_put_request(fc, req);
2696 free_page((unsigned long) iov_page);
2698 __free_page(pages[--num_pages]);
2701 return err ? err : outarg.result;
2703 EXPORT_SYMBOL_GPL(fuse_do_ioctl);
2705 long fuse_ioctl_common(struct file *file, unsigned int cmd,
2706 unsigned long arg, unsigned int flags)
2708 struct inode *inode = file_inode(file);
2709 struct fuse_conn *fc = get_fuse_conn(inode);
2711 if (!fuse_allow_current_process(fc))
2714 if (is_bad_inode(inode))
2717 return fuse_do_ioctl(file, cmd, arg, flags);
2720 static long fuse_file_ioctl(struct file *file, unsigned int cmd,
2723 return fuse_ioctl_common(file, cmd, arg, 0);
2726 static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
2729 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
2733 * All files which have been polled are linked to RB tree
2734 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2735 * find the matching one.
2737 static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
2738 struct rb_node **parent_out)
2740 struct rb_node **link = &fc->polled_files.rb_node;
2741 struct rb_node *last = NULL;
2744 struct fuse_file *ff;
2747 ff = rb_entry(last, struct fuse_file, polled_node);
2750 link = &last->rb_left;
2751 else if (kh > ff->kh)
2752 link = &last->rb_right;
2763 * The file is about to be polled. Make sure it's on the polled_files
2764 * RB tree. Note that files once added to the polled_files tree are
2765 * not removed before the file is released. This is because a file
2766 * polled once is likely to be polled again.
2768 static void fuse_register_polled_file(struct fuse_conn *fc,
2769 struct fuse_file *ff)
2771 spin_lock(&fc->lock);
2772 if (RB_EMPTY_NODE(&ff->polled_node)) {
2773 struct rb_node **link, *uninitialized_var(parent);
2775 link = fuse_find_polled_node(fc, ff->kh, &parent);
2777 rb_link_node(&ff->polled_node, parent, link);
2778 rb_insert_color(&ff->polled_node, &fc->polled_files);
2780 spin_unlock(&fc->lock);
2783 unsigned fuse_file_poll(struct file *file, poll_table *wait)
2785 struct fuse_file *ff = file->private_data;
2786 struct fuse_conn *fc = ff->fc;
2787 struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
2788 struct fuse_poll_out outarg;
2789 struct fuse_req *req;
2793 return DEFAULT_POLLMASK;
2795 poll_wait(file, &ff->poll_wait, wait);
2796 inarg.events = (__u32)poll_requested_events(wait);
2799 * Ask for notification iff there's someone waiting for it.
2800 * The client may ignore the flag and always notify.
2802 if (waitqueue_active(&ff->poll_wait)) {
2803 inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
2804 fuse_register_polled_file(fc, ff);
2807 req = fuse_get_req_nopages(fc);
2811 req->in.h.opcode = FUSE_POLL;
2812 req->in.h.nodeid = ff->nodeid;
2813 req->in.numargs = 1;
2814 req->in.args[0].size = sizeof(inarg);
2815 req->in.args[0].value = &inarg;
2816 req->out.numargs = 1;
2817 req->out.args[0].size = sizeof(outarg);
2818 req->out.args[0].value = &outarg;
2819 fuse_request_send(fc, req);
2820 err = req->out.h.error;
2821 fuse_put_request(fc, req);
2824 return outarg.revents;
2825 if (err == -ENOSYS) {
2827 return DEFAULT_POLLMASK;
2831 EXPORT_SYMBOL_GPL(fuse_file_poll);
2834 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2835 * wakes up the poll waiters.
2837 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
2838 struct fuse_notify_poll_wakeup_out *outarg)
2840 u64 kh = outarg->kh;
2841 struct rb_node **link;
2843 spin_lock(&fc->lock);
2845 link = fuse_find_polled_node(fc, kh, NULL);
2847 struct fuse_file *ff;
2849 ff = rb_entry(*link, struct fuse_file, polled_node);
2850 wake_up_interruptible_sync(&ff->poll_wait);
2853 spin_unlock(&fc->lock);
2857 static void fuse_do_truncate(struct file *file)
2859 struct inode *inode = file->f_mapping->host;
2862 attr.ia_valid = ATTR_SIZE;
2863 attr.ia_size = i_size_read(inode);
2865 attr.ia_file = file;
2866 attr.ia_valid |= ATTR_FILE;
2868 fuse_do_setattr(inode, &attr, file);
2871 static inline loff_t fuse_round_up(loff_t off)
2873 return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
2877 fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
2878 loff_t offset, unsigned long nr_segs)
2881 struct file *file = iocb->ki_filp;
2882 struct fuse_file *ff = file->private_data;
2883 bool async_dio = ff->fc->async_dio;
2885 struct inode *inode;
2887 size_t count = iov_length(iov, nr_segs);
2888 struct fuse_io_priv *io;
2891 inode = file->f_mapping->host;
2892 i_size = i_size_read(inode);
2894 if ((rw == READ) && (offset > i_size))
2897 /* optimization for short read */
2898 if (async_dio && rw != WRITE && offset + count > i_size) {
2899 if (offset >= i_size)
2901 count = min_t(loff_t, count, fuse_round_up(i_size - offset));
2904 io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
2907 spin_lock_init(&io->lock);
2911 io->offset = offset;
2912 io->write = (rw == WRITE);
2916 * By default, we want to optimize all I/Os with async request
2917 * submission to the client filesystem if supported.
2919 io->async = async_dio;
2923 * We cannot asynchronously extend the size of a file. We have no method
2924 * to wait on real async I/O requests, so we must submit this request
2927 if (!is_sync_kiocb(iocb) && (offset + count > i_size) && rw == WRITE)
2931 ret = __fuse_direct_write(io, iov, nr_segs, &pos);
2933 ret = __fuse_direct_read(io, iov, nr_segs, &pos, count);
2936 fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
2938 /* we have a non-extending, async request, so return */
2939 if (!is_sync_kiocb(iocb))
2940 return -EIOCBQUEUED;
2942 ret = wait_on_sync_kiocb(iocb);
2949 fuse_write_update_size(inode, pos);
2950 else if (ret < 0 && offset + count > i_size)
2951 fuse_do_truncate(file);
2957 static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
2960 struct fuse_file *ff = file->private_data;
2961 struct inode *inode = file->f_inode;
2962 struct fuse_inode *fi = get_fuse_inode(inode);
2963 struct fuse_conn *fc = ff->fc;
2964 struct fuse_req *req;
2965 struct fuse_fallocate_in inarg = {
2972 bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) ||
2973 (mode & FALLOC_FL_PUNCH_HOLE);
2975 if (fc->no_fallocate)
2979 mutex_lock(&inode->i_mutex);
2980 if (mode & FALLOC_FL_PUNCH_HOLE) {
2981 loff_t endbyte = offset + length - 1;
2982 err = filemap_write_and_wait_range(inode->i_mapping,
2987 fuse_sync_writes(inode);
2991 if (!(mode & FALLOC_FL_KEEP_SIZE))
2992 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
2994 req = fuse_get_req_nopages(fc);
3000 req->in.h.opcode = FUSE_FALLOCATE;
3001 req->in.h.nodeid = ff->nodeid;
3002 req->in.numargs = 1;
3003 req->in.args[0].size = sizeof(inarg);
3004 req->in.args[0].value = &inarg;
3005 fuse_request_send(fc, req);
3006 err = req->out.h.error;
3007 if (err == -ENOSYS) {
3008 fc->no_fallocate = 1;
3011 fuse_put_request(fc, req);
3016 /* we could have extended the file */
3017 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
3018 bool changed = fuse_write_update_size(inode, offset + length);
3020 if (changed && fc->writeback_cache) {
3021 struct fuse_inode *fi = get_fuse_inode(inode);
3023 inode->i_mtime = current_fs_time(inode->i_sb);
3024 set_bit(FUSE_I_MTIME_DIRTY, &fi->state);
3028 if (mode & FALLOC_FL_PUNCH_HOLE)
3029 truncate_pagecache_range(inode, offset, offset + length - 1);
3031 fuse_invalidate_attr(inode);
3034 if (!(mode & FALLOC_FL_KEEP_SIZE))
3035 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
3038 mutex_unlock(&inode->i_mutex);
3043 static const struct file_operations fuse_file_operations = {
3044 .llseek = fuse_file_llseek,
3045 .read = do_sync_read,
3046 .aio_read = fuse_file_aio_read,
3047 .write = do_sync_write,
3048 .aio_write = fuse_file_aio_write,
3049 .mmap = fuse_file_mmap,
3051 .flush = fuse_flush,
3052 .release = fuse_release,
3053 .fsync = fuse_fsync,
3054 .lock = fuse_file_lock,
3055 .flock = fuse_file_flock,
3056 .splice_read = generic_file_splice_read,
3057 .unlocked_ioctl = fuse_file_ioctl,
3058 .compat_ioctl = fuse_file_compat_ioctl,
3059 .poll = fuse_file_poll,
3060 .fallocate = fuse_file_fallocate,
3063 static const struct file_operations fuse_direct_io_file_operations = {
3064 .llseek = fuse_file_llseek,
3065 .read = fuse_direct_read,
3066 .write = fuse_direct_write,
3067 .mmap = fuse_direct_mmap,
3069 .flush = fuse_flush,
3070 .release = fuse_release,
3071 .fsync = fuse_fsync,
3072 .lock = fuse_file_lock,
3073 .flock = fuse_file_flock,
3074 .unlocked_ioctl = fuse_file_ioctl,
3075 .compat_ioctl = fuse_file_compat_ioctl,
3076 .poll = fuse_file_poll,
3077 .fallocate = fuse_file_fallocate,
3078 /* no splice_read */
3081 static const struct address_space_operations fuse_file_aops = {
3082 .readpage = fuse_readpage,
3083 .writepage = fuse_writepage,
3084 .writepages = fuse_writepages,
3085 .launder_page = fuse_launder_page,
3086 .readpages = fuse_readpages,
3087 .set_page_dirty = __set_page_dirty_nobuffers,
3089 .direct_IO = fuse_direct_IO,
3090 .write_begin = fuse_write_begin,
3091 .write_end = fuse_write_end,
3094 void fuse_init_file_inode(struct inode *inode)
3096 inode->i_fop = &fuse_file_operations;
3097 inode->i_data.a_ops = &fuse_file_aops;