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fuse: fix copy_file_range() in the writeback case
[linux-block.git] / fs / fuse / file.c
CommitLineData
b6aeaded
MS		 1/*
2 FUSE: Filesystem in Userspace
1729a16c 3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
b6aeaded
MS		 4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7*/
8
9#include "fuse_i.h"
10
11#include <linux/pagemap.h>
12#include <linux/slab.h>
13#include <linux/kernel.h>
e8edc6e0 14#include <linux/sched.h>
7a36094d 15#include <linux/sched/signal.h>
08cbf542 16#include <linux/module.h>
d9d318d3 17#include <linux/compat.h>
478e0841 18#include <linux/swap.h>
3634a632 19#include <linux/falloc.h>
e2e40f2c 20#include <linux/uio.h>
b6aeaded 21
91fe96b4
MS		 22static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
23 int opcode, struct fuse_open_out *outargp)
b6aeaded 24{
b6aeaded 25 struct fuse_open_in inarg;
7078187a 26 FUSE_ARGS(args);
fd72faac
MS		 27
28 memset(&inarg, 0, sizeof(inarg));
6ff958ed
MS		 29 inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
30 if (!fc->atomic_o_trunc)
31 inarg.flags &= ~O_TRUNC;
7078187a
MS		 32 args.in.h.opcode = opcode;
33 args.in.h.nodeid = nodeid;
34 args.in.numargs = 1;
35 args.in.args[0].size = sizeof(inarg);
36 args.in.args[0].value = &inarg;
37 args.out.numargs = 1;
38 args.out.args[0].size = sizeof(*outargp);
39 args.out.args[0].value = outargp;
fd72faac 40
7078187a 41 return fuse_simple_request(fc, &args);
fd72faac
MS		 42}
43
acf99433 44struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
fd72faac
MS		 45{
46 struct fuse_file *ff;
6b2db28a 47
68227c03 48 ff = kzalloc(sizeof(struct fuse_file), GFP_KERNEL);
6b2db28a
TH		 49 if (unlikely(!ff))
50 return NULL;
51
da5e4714 52 ff->fc = fc;
4250c066 53 ff->reserved_req = fuse_request_alloc(0);
6b2db28a
TH		 54 if (unlikely(!ff->reserved_req)) {
55 kfree(ff);
56 return NULL;
fd72faac 57 }
6b2db28a
TH		 58
59 INIT_LIST_HEAD(&ff->write_entry);
5d7bc7e8 60 mutex_init(&ff->readdir.lock);
4e8c2eb5 61 refcount_set(&ff->count, 1);
6b2db28a
TH		 62 RB_CLEAR_NODE(&ff->polled_node);
63 init_waitqueue_head(&ff->poll_wait);
64
75126f55 65 ff->kh = atomic64_inc_return(&fc->khctr);
6b2db28a 66
fd72faac
MS		 67 return ff;
68}
69
70void fuse_file_free(struct fuse_file *ff)
71{
33649c91 72 fuse_request_free(ff->reserved_req);
5d7bc7e8 73 mutex_destroy(&ff->readdir.lock);
fd72faac
MS		 74 kfree(ff);
75}
76
267d8444 77static struct fuse_file *fuse_file_get(struct fuse_file *ff)
c756e0a4 78{
4e8c2eb5 79 refcount_inc(&ff->count);
c756e0a4
MS		 80 return ff;
81}
82
819c4b3b
MS		 83static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
84{
baebccbe 85 iput(req->misc.release.inode);
819c4b3b
MS		 86}
87
2e64ff15 88static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir)
c756e0a4 89{
4e8c2eb5 90 if (refcount_dec_and_test(&ff->count)) {
c756e0a4 91 struct fuse_req *req = ff->reserved_req;
8b0797a4 92
d9a9ea94 93 if (isdir ? ff->fc->no_opendir : ff->fc->no_open) {
7678ac50
AG		 94 /*
95 * Drop the release request when client does not
96 * implement 'open'
97 */
825d6d33 98 __clear_bit(FR_BACKGROUND, &req->flags);
baebccbe 99 iput(req->misc.release.inode);
7678ac50
AG		 100 fuse_put_request(ff->fc, req);
101 } else if (sync) {
2e38bea9 102 __set_bit(FR_FORCE, &req->flags);
825d6d33 103 __clear_bit(FR_BACKGROUND, &req->flags);
5a18ec17 104 fuse_request_send(ff->fc, req);
baebccbe 105 iput(req->misc.release.inode);
5a18ec17
MS		 106 fuse_put_request(ff->fc, req);
107 } else {
108 req->end = fuse_release_end;
825d6d33 109 __set_bit(FR_BACKGROUND, &req->flags);
5a18ec17
MS		 110 fuse_request_send_background(ff->fc, req);
111 }
c756e0a4
MS		 112 kfree(ff);
113 }
114}
115
08cbf542
TH		 116int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
117 bool isdir)
91fe96b4 118{
91fe96b4 119 struct fuse_file *ff;
91fe96b4
MS		 120 int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
121
122 ff = fuse_file_alloc(fc);
123 if (!ff)
124 return -ENOMEM;
125
7678ac50 126 ff->fh = 0;
fabf7e02
CA		 127 /* Default for no-open */
128 ff->open_flags = FOPEN_KEEP_CACHE | (isdir ? FOPEN_CACHE_DIR : 0);
d9a9ea94 129 if (isdir ? !fc->no_opendir : !fc->no_open) {
7678ac50
AG		 130 struct fuse_open_out outarg;
131 int err;
132
133 err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
134 if (!err) {
135 ff->fh = outarg.fh;
136 ff->open_flags = outarg.open_flags;
137
d9a9ea94 138 } else if (err != -ENOSYS) {
7678ac50
AG		 139 fuse_file_free(ff);
140 return err;
141 } else {
d9a9ea94
CA		 142 if (isdir)
143 fc->no_opendir = 1;
144 else
145 fc->no_open = 1;
7678ac50 146 }
91fe96b4
MS		 147 }
148
149 if (isdir)
7678ac50 150 ff->open_flags &= ~FOPEN_DIRECT_IO;
91fe96b4 151
91fe96b4 152 ff->nodeid = nodeid;
267d8444 153 file->private_data = ff;
91fe96b4
MS		 154
155 return 0;
156}
08cbf542 157EXPORT_SYMBOL_GPL(fuse_do_open);
91fe96b4 158
650b22b9
PE		 159static void fuse_link_write_file(struct file *file)
160{
161 struct inode *inode = file_inode(file);
650b22b9
PE		 162 struct fuse_inode *fi = get_fuse_inode(inode);
163 struct fuse_file *ff = file->private_data;
164 /*
165 * file may be written through mmap, so chain it onto the
166 * inodes's write_file list
167 */
f15ecfef 168 spin_lock(&fi->lock);
650b22b9
PE		 169 if (list_empty(&ff->write_entry))
170 list_add(&ff->write_entry, &fi->write_files);
f15ecfef 171 spin_unlock(&fi->lock);
650b22b9
PE		 172}
173
c7b7143c 174void fuse_finish_open(struct inode *inode, struct file *file)
fd72faac 175{
c7b7143c 176 struct fuse_file *ff = file->private_data;
a0822c55 177 struct fuse_conn *fc = get_fuse_conn(inode);
c7b7143c 178
c7b7143c 179 if (!(ff->open_flags & FOPEN_KEEP_CACHE))
b1009979 180 invalidate_inode_pages2(inode->i_mapping);
bbd84f33
KS		 181 if (ff->open_flags & FOPEN_STREAM)
182 stream_open(inode, file);
183 else if (ff->open_flags & FOPEN_NONSEEKABLE)
a7c1b990 184 nonseekable_open(inode, file);
a0822c55
KS		 185 if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
186 struct fuse_inode *fi = get_fuse_inode(inode);
187
f15ecfef 188 spin_lock(&fi->lock);
4510d86f 189 fi->attr_version = atomic64_inc_return(&fc->attr_version);
a0822c55 190 i_size_write(inode, 0);
f15ecfef 191 spin_unlock(&fi->lock);
a0822c55 192 fuse_invalidate_attr(inode);
75caeecd
MP		 193 if (fc->writeback_cache)
194 file_update_time(file);
a0822c55 195 }
4d99ff8f
PE		 196 if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
197 fuse_link_write_file(file);
fd72faac
MS		 198}
199
91fe96b4 200int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
fd72faac 201{
acf99433 202 struct fuse_conn *fc = get_fuse_conn(inode);
b6aeaded 203 int err;
75caeecd
MP		 204 bool lock_inode = (file->f_flags & O_TRUNC) &&
205 fc->atomic_o_trunc &&
206 fc->writeback_cache;
b6aeaded
MS		 207
208 err = generic_file_open(inode, file);
209 if (err)
210 return err;
211
75caeecd 212 if (lock_inode)
5955102c 213 inode_lock(inode);
75caeecd 214
91fe96b4 215 err = fuse_do_open(fc, get_node_id(inode), file, isdir);
b6aeaded 216
75caeecd
MP		 217 if (!err)
218 fuse_finish_open(inode, file);
91fe96b4 219
75caeecd 220 if (lock_inode)
5955102c 221 inode_unlock(inode);
75caeecd
MP		 222
223 return err;
b6aeaded
MS		 224}
225
ebf84d0c
KT		 226static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
227 int flags, int opcode)
64c6d8ed 228{
8b0797a4 229 struct fuse_conn *fc = ff->fc;
33649c91 230 struct fuse_req *req = ff->reserved_req;
b57d4264 231 struct fuse_release_in *inarg = &req->misc.release.in;
b6aeaded 232
f15ecfef
KT		 233 /* Inode is NULL on error path of fuse_create_open() */
234 if (likely(fi)) {
235 spin_lock(&fi->lock);
236 list_del(&ff->write_entry);
237 spin_unlock(&fi->lock);
238 }
8b0797a4 239 spin_lock(&fc->lock);
8b0797a4
MS		 240 if (!RB_EMPTY_NODE(&ff->polled_node))
241 rb_erase(&ff->polled_node, &fc->polled_files);
242 spin_unlock(&fc->lock);
243
357ccf2b 244 wake_up_interruptible_all(&ff->poll_wait);
8b0797a4 245
b6aeaded 246 inarg->fh = ff->fh;
fd72faac 247 inarg->flags = flags;
51eb01e7 248 req->in.h.opcode = opcode;
c7b7143c 249 req->in.h.nodeid = ff->nodeid;
b6aeaded
MS		 250 req->in.numargs = 1;
251 req->in.args[0].size = sizeof(struct fuse_release_in);
252 req->in.args[0].value = inarg;
fd72faac
MS		 253}
254
2e64ff15 255void fuse_release_common(struct file *file, bool isdir)
fd72faac 256{
ebf84d0c 257 struct fuse_inode *fi = get_fuse_inode(file_inode(file));
9a87ad3d
MS		 258 struct fuse_file *ff = file->private_data;
259 struct fuse_req *req = ff->reserved_req;
2e64ff15 260 int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
6b2db28a 261
ebf84d0c 262 fuse_prepare_release(fi, ff, file->f_flags, opcode);
6b2db28a 263
37fb3a30
MS		 264 if (ff->flock) {
265 struct fuse_release_in *inarg = &req->misc.release.in;
266 inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
267 inarg->lock_owner = fuse_lock_owner_id(ff->fc,
268 (fl_owner_t) file);
269 }
baebccbe
MS		 270 /* Hold inode until release is finished */
271 req->misc.release.inode = igrab(file_inode(file));
6b2db28a 272
6b2db28a
TH		 273 /*
274 * Normally this will send the RELEASE request, however if
275 * some asynchronous READ or WRITE requests are outstanding,
276 * the sending will be delayed.
5a18ec17
MS		 277 *
278 * Make the release synchronous if this is a fuseblk mount,
279 * synchronous RELEASE is allowed (and desirable) in this case
280 * because the server can be trusted not to screw up.
6b2db28a 281 */
2e64ff15 282 fuse_file_put(ff, ff->fc->destroy_req != NULL, isdir);
b6aeaded
MS		 283}
284
04730fef
MS		 285static int fuse_open(struct inode *inode, struct file *file)
286{
91fe96b4 287 return fuse_open_common(inode, file, false);
04730fef
MS		 288}
289
290static int fuse_release(struct inode *inode, struct file *file)
291{
e7cc133c
PE		 292 struct fuse_conn *fc = get_fuse_conn(inode);
293
294 /* see fuse_vma_close() for !writeback_cache case */
295 if (fc->writeback_cache)
1e18bda8 296 write_inode_now(inode, 1);
b0aa7606 297
2e64ff15 298 fuse_release_common(file, false);
8b0797a4
MS		 299
300 /* return value is ignored by VFS */
301 return 0;
302}
303
ebf84d0c 304void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags)
8b0797a4 305{
4e8c2eb5 306 WARN_ON(refcount_read(&ff->count) > 1);
ebf84d0c 307 fuse_prepare_release(fi, ff, flags, FUSE_RELEASE);
267d8444
MS		 308 /*
309 * iput(NULL) is a no-op and since the refcount is 1 and everything's
310 * synchronous, we are fine with not doing igrab() here"
311 */
2e64ff15 312 fuse_file_put(ff, true, false);
04730fef 313}
08cbf542 314EXPORT_SYMBOL_GPL(fuse_sync_release);
04730fef 315
71421259 316/*
9c8ef561
MS		 317 * Scramble the ID space with XTEA, so that the value of the files_struct
318 * pointer is not exposed to userspace.
71421259 319 */
f3332114 320u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
71421259 321{
9c8ef561
MS		 322 u32 *k = fc->scramble_key;
323 u64 v = (unsigned long) id;
324 u32 v0 = v;
325 u32 v1 = v >> 32;
326 u32 sum = 0;
327 int i;
328
329 for (i = 0; i < 32; i++) {
330 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
331 sum += 0x9E3779B9;
332 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
333 }
334
335 return (u64) v0 + ((u64) v1 << 32);
71421259
MS		 336}
337
2fe93bd4
MS		 338static struct fuse_req *fuse_find_writeback(struct fuse_inode *fi,
339 pgoff_t idx_from, pgoff_t idx_to)
340{
341 struct fuse_req *req;
342
343 list_for_each_entry(req, &fi->writepages, writepages_entry) {
344 pgoff_t curr_index;
345
346 WARN_ON(get_fuse_inode(req->inode) != fi);
347 curr_index = req->misc.write.in.offset >> PAGE_SHIFT;
348 if (idx_from < curr_index + req->num_pages &&
349 curr_index <= idx_to) {
350 return req;
351 }
352 }
353 return NULL;
354}
355
3be5a52b 356/*
ea8cd333 357 * Check if any page in a range is under writeback
3be5a52b
MS		 358 *
359 * This is currently done by walking the list of writepage requests
360 * for the inode, which can be pretty inefficient.
361 */
ea8cd333
PE		 362static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from,
363 pgoff_t idx_to)
3be5a52b 364{
3be5a52b 365 struct fuse_inode *fi = get_fuse_inode(inode);
2fe93bd4 366 bool found;
3be5a52b 367
f15ecfef 368 spin_lock(&fi->lock);
2fe93bd4 369 found = fuse_find_writeback(fi, idx_from, idx_to);
f15ecfef 370 spin_unlock(&fi->lock);
3be5a52b
MS		 371
372 return found;
373}
374
ea8cd333
PE		 375static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
376{
377 return fuse_range_is_writeback(inode, index, index);
378}
379
3be5a52b
MS		 380/*
381 * Wait for page writeback to be completed.
382 *
383 * Since fuse doesn't rely on the VM writeback tracking, this has to
384 * use some other means.
385 */
386static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
387{
388 struct fuse_inode *fi = get_fuse_inode(inode);
389
390 wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
391 return 0;
392}
393
fe38d7df
MP		 394/*
395 * Wait for all pending writepages on the inode to finish.
396 *
397 * This is currently done by blocking further writes with FUSE_NOWRITE
398 * and waiting for all sent writes to complete.
399 *
400 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
401 * could conflict with truncation.
402 */
403static void fuse_sync_writes(struct inode *inode)
404{
405 fuse_set_nowrite(inode);
406 fuse_release_nowrite(inode);
407}
408
75e1fcc0 409static int fuse_flush(struct file *file, fl_owner_t id)
b6aeaded 410{
6131ffaa 411 struct inode *inode = file_inode(file);
b6aeaded
MS		 412 struct fuse_conn *fc = get_fuse_conn(inode);
413 struct fuse_file *ff = file->private_data;
414 struct fuse_req *req;
415 struct fuse_flush_in inarg;
416 int err;
417
248d86e8
MS		 418 if (is_bad_inode(inode))
419 return -EIO;
420
b6aeaded
MS		 421 if (fc->no_flush)
422 return 0;
423
1e18bda8 424 err = write_inode_now(inode, 1);
fe38d7df
MP		 425 if (err)
426 return err;
427
5955102c 428 inode_lock(inode);
fe38d7df 429 fuse_sync_writes(inode);
5955102c 430 inode_unlock(inode);
fe38d7df 431
4a7f4e88 432 err = filemap_check_errors(file->f_mapping);
9ebce595
MP		 433 if (err)
434 return err;
435
b111c8c0 436 req = fuse_get_req_nofail_nopages(fc, file);
b6aeaded
MS		 437 memset(&inarg, 0, sizeof(inarg));
438 inarg.fh = ff->fh;
9c8ef561 439 inarg.lock_owner = fuse_lock_owner_id(fc, id);
b6aeaded
MS		 440 req->in.h.opcode = FUSE_FLUSH;
441 req->in.h.nodeid = get_node_id(inode);
b6aeaded
MS		 442 req->in.numargs = 1;
443 req->in.args[0].size = sizeof(inarg);
444 req->in.args[0].value = &inarg;
825d6d33 445 __set_bit(FR_FORCE, &req->flags);
b93f858a 446 fuse_request_send(fc, req);
b6aeaded
MS		 447 err = req->out.h.error;
448 fuse_put_request(fc, req);
449 if (err == -ENOSYS) {
450 fc->no_flush = 1;
451 err = 0;
452 }
453 return err;
454}
455
02c24a82 456int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
a9c2d1e8 457 int datasync, int opcode)
b6aeaded 458{
7ea80859 459 struct inode *inode = file->f_mapping->host;
b6aeaded
MS		 460 struct fuse_conn *fc = get_fuse_conn(inode);
461 struct fuse_file *ff = file->private_data;
7078187a 462 FUSE_ARGS(args);
b6aeaded 463 struct fuse_fsync_in inarg;
a9c2d1e8
MS		 464
465 memset(&inarg, 0, sizeof(inarg));
466 inarg.fh = ff->fh;
154603fe 467 inarg.fsync_flags = datasync ? FUSE_FSYNC_FDATASYNC : 0;
a9c2d1e8
MS		 468 args.in.h.opcode = opcode;
469 args.in.h.nodeid = get_node_id(inode);
470 args.in.numargs = 1;
471 args.in.args[0].size = sizeof(inarg);
472 args.in.args[0].value = &inarg;
473 return fuse_simple_request(fc, &args);
474}
475
476static int fuse_fsync(struct file *file, loff_t start, loff_t end,
477 int datasync)
478{
479 struct inode *inode = file->f_mapping->host;
480 struct fuse_conn *fc = get_fuse_conn(inode);
b6aeaded
MS		 481 int err;
482
248d86e8
MS		 483 if (is_bad_inode(inode))
484 return -EIO;
485
5955102c 486 inode_lock(inode);
02c24a82 487
3be5a52b
MS		 488 /*
489 * Start writeback against all dirty pages of the inode, then
490 * wait for all outstanding writes, before sending the FSYNC
491 * request.
492 */
7e51fe1d 493 err = file_write_and_wait_range(file, start, end);
3be5a52b 494 if (err)
02c24a82 495 goto out;
3be5a52b
MS		 496
497 fuse_sync_writes(inode);
ac7f052b
AK		 498
499 /*
500 * Due to implementation of fuse writeback
7e51fe1d 501 * file_write_and_wait_range() does not catch errors.
ac7f052b
AK		 502 * We have to do this directly after fuse_sync_writes()
503 */
7e51fe1d 504 err = file_check_and_advance_wb_err(file);
ac7f052b
AK		 505 if (err)
506 goto out;
507
1e18bda8
MS		 508 err = sync_inode_metadata(inode, 1);
509 if (err)
510 goto out;
3be5a52b 511
a9c2d1e8 512 if (fc->no_fsync)
22401e7b 513 goto out;
b0aa7606 514
a9c2d1e8 515 err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNC);
b6aeaded 516 if (err == -ENOSYS) {
a9c2d1e8 517 fc->no_fsync = 1;
b6aeaded
MS		 518 err = 0;
519 }
02c24a82 520out:
5955102c 521 inode_unlock(inode);
b6aeaded 522
a9c2d1e8 523 return err;
82547981
MS		 524}
525
2106cb18
MS		 526void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
527 size_t count, int opcode)
b6aeaded 528{
5c5c5e51 529 struct fuse_read_in *inarg = &req->misc.read.in;
a6643094 530 struct fuse_file *ff = file->private_data;
b6aeaded 531
361b1eb5
MS		 532 inarg->fh = ff->fh;
533 inarg->offset = pos;
534 inarg->size = count;
a6643094 535 inarg->flags = file->f_flags;
361b1eb5 536 req->in.h.opcode = opcode;
2106cb18 537 req->in.h.nodeid = ff->nodeid;
b6aeaded
MS		 538 req->in.numargs = 1;
539 req->in.args[0].size = sizeof(struct fuse_read_in);
c1aa96a5 540 req->in.args[0].value = inarg;
b6aeaded
MS		 541 req->out.argvar = 1;
542 req->out.numargs = 1;
543 req->out.args[0].size = count;
b6aeaded
MS		 544}
545
8fba54ae 546static void fuse_release_user_pages(struct fuse_req *req, bool should_dirty)
187c5c36
MP		 547{
548 unsigned i;
549
550 for (i = 0; i < req->num_pages; i++) {
551 struct page *page = req->pages[i];
8fba54ae 552 if (should_dirty)
187c5c36
MP		 553 set_page_dirty_lock(page);
554 put_page(page);
555 }
556}
557
744742d6
SF		 558static void fuse_io_release(struct kref *kref)
559{
560 kfree(container_of(kref, struct fuse_io_priv, refcnt));
561}
562
9d5722b7
CH		 563static ssize_t fuse_get_res_by_io(struct fuse_io_priv *io)
564{
565 if (io->err)
566 return io->err;
567
568 if (io->bytes >= 0 && io->write)
569 return -EIO;
570
571 return io->bytes < 0 ? io->size : io->bytes;
572}
573
01e9d11a
MP		 574/**
575 * In case of short read, the caller sets 'pos' to the position of
576 * actual end of fuse request in IO request. Otherwise, if bytes_requested
577 * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.
578 *
579 * An example:
580 * User requested DIO read of 64K. It was splitted into two 32K fuse requests,
581 * both submitted asynchronously. The first of them was ACKed by userspace as
582 * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The
583 * second request was ACKed as short, e.g. only 1K was read, resulting in
584 * pos == 33K.
585 *
586 * Thus, when all fuse requests are completed, the minimal non-negative 'pos'
587 * will be equal to the length of the longest contiguous fragment of
588 * transferred data starting from the beginning of IO request.
589 */
590static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
591{
592 int left;
593
594 spin_lock(&io->lock);
595 if (err)
596 io->err = io->err ? : err;
597 else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes))
598 io->bytes = pos;
599
600 left = --io->reqs;
7879c4e5 601 if (!left && io->blocking)
9d5722b7 602 complete(io->done);
01e9d11a
MP		 603 spin_unlock(&io->lock);
604
7879c4e5 605 if (!left && !io->blocking) {
9d5722b7 606 ssize_t res = fuse_get_res_by_io(io);
01e9d11a 607
9d5722b7
CH		 608 if (res >= 0) {
609 struct inode *inode = file_inode(io->iocb->ki_filp);
610 struct fuse_conn *fc = get_fuse_conn(inode);
611 struct fuse_inode *fi = get_fuse_inode(inode);
01e9d11a 612
f15ecfef 613 spin_lock(&fi->lock);
4510d86f 614 fi->attr_version = atomic64_inc_return(&fc->attr_version);
f15ecfef 615 spin_unlock(&fi->lock);
01e9d11a
MP		 616 }
617
04b2fa9f 618 io->iocb->ki_complete(io->iocb, res, 0);
01e9d11a 619 }
744742d6
SF		 620
621 kref_put(&io->refcnt, fuse_io_release);
01e9d11a
MP		 622}
623
624static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
625{
626 struct fuse_io_priv *io = req->io;
627 ssize_t pos = -1;
628
61c12b49 629 fuse_release_user_pages(req, io->should_dirty);
01e9d11a
MP		 630
631 if (io->write) {
632 if (req->misc.write.in.size != req->misc.write.out.size)
633 pos = req->misc.write.in.offset - io->offset +
634 req->misc.write.out.size;
635 } else {
636 if (req->misc.read.in.size != req->out.args[0].size)
637 pos = req->misc.read.in.offset - io->offset +
638 req->out.args[0].size;
639 }
640
641 fuse_aio_complete(io, req->out.h.error, pos);
642}
643
644static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
645 size_t num_bytes, struct fuse_io_priv *io)
646{
647 spin_lock(&io->lock);
744742d6 648 kref_get(&io->refcnt);
01e9d11a
MP		 649 io->size += num_bytes;
650 io->reqs++;
651 spin_unlock(&io->lock);
652
653 req->io = io;
654 req->end = fuse_aio_complete_req;
655
36cf66ed 656 __fuse_get_request(req);
01e9d11a
MP		 657 fuse_request_send_background(fc, req);
658
659 return num_bytes;
660}
661
36cf66ed 662static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
2106cb18 663 loff_t pos, size_t count, fl_owner_t owner)
04730fef 664{
e1c0eecb 665 struct file *file = io->iocb->ki_filp;
2106cb18
MS		 666 struct fuse_file *ff = file->private_data;
667 struct fuse_conn *fc = ff->fc;
f3332114 668
2106cb18 669 fuse_read_fill(req, file, pos, count, FUSE_READ);
f3332114 670 if (owner != NULL) {
5c5c5e51 671 struct fuse_read_in *inarg = &req->misc.read.in;
f3332114
MS		 672
673 inarg->read_flags |= FUSE_READ_LOCKOWNER;
674 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
675 }
36cf66ed
MP		 676
677 if (io->async)
678 return fuse_async_req_send(fc, req, count, io);
679
b93f858a 680 fuse_request_send(fc, req);
361b1eb5 681 return req->out.args[0].size;
04730fef
MS		 682}
683
5c5c5e51
MS		 684static void fuse_read_update_size(struct inode *inode, loff_t size,
685 u64 attr_ver)
686{
687 struct fuse_conn *fc = get_fuse_conn(inode);
688 struct fuse_inode *fi = get_fuse_inode(inode);
689
f15ecfef 690 spin_lock(&fi->lock);
06a7c3c2
MP		 691 if (attr_ver == fi->attr_version && size < inode->i_size &&
692 !test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
4510d86f 693 fi->attr_version = atomic64_inc_return(&fc->attr_version);
5c5c5e51
MS		 694 i_size_write(inode, size);
695 }
f15ecfef 696 spin_unlock(&fi->lock);
5c5c5e51
MS		 697}
698
a92adc82
PE		 699static void fuse_short_read(struct fuse_req *req, struct inode *inode,
700 u64 attr_ver)
701{
702 size_t num_read = req->out.args[0].size;
8373200b
PE		 703 struct fuse_conn *fc = get_fuse_conn(inode);
704
705 if (fc->writeback_cache) {
706 /*
707 * A hole in a file. Some data after the hole are in page cache,
708 * but have not reached the client fs yet. So, the hole is not
709 * present there.
710 */
711 int i;
09cbfeaf
KS		 712 int start_idx = num_read >> PAGE_SHIFT;
713 size_t off = num_read & (PAGE_SIZE - 1);
a92adc82 714
8373200b 715 for (i = start_idx; i < req->num_pages; i++) {
09cbfeaf 716 zero_user_segment(req->pages[i], off, PAGE_SIZE);
8373200b
PE		 717 off = 0;
718 }
719 } else {
720 loff_t pos = page_offset(req->pages[0]) + num_read;
721 fuse_read_update_size(inode, pos, attr_ver);
722 }
a92adc82
PE		 723}
724
482fce55 725static int fuse_do_readpage(struct file *file, struct page *page)
b6aeaded 726{
e1c0eecb
MS		 727 struct kiocb iocb;
728 struct fuse_io_priv io;
b6aeaded
MS		 729 struct inode *inode = page->mapping->host;
730 struct fuse_conn *fc = get_fuse_conn(inode);
248d86e8 731 struct fuse_req *req;
5c5c5e51
MS		 732 size_t num_read;
733 loff_t pos = page_offset(page);
09cbfeaf 734 size_t count = PAGE_SIZE;
5c5c5e51 735 u64 attr_ver;
248d86e8
MS		 736 int err;
737
3be5a52b 738 /*
25985edc 739 * Page writeback can extend beyond the lifetime of the
3be5a52b
MS		 740 * page-cache page, so make sure we read a properly synced
741 * page.
742 */
743 fuse_wait_on_page_writeback(inode, page->index);
744
b111c8c0 745 req = fuse_get_req(fc, 1);
ce1d5a49 746 if (IS_ERR(req))
482fce55 747 return PTR_ERR(req);
b6aeaded 748
5c5c5e51
MS		 749 attr_ver = fuse_get_attr_version(fc);
750
b6aeaded 751 req->out.page_zeroing = 1;
f4975c67 752 req->out.argpages = 1;
b6aeaded
MS		 753 req->num_pages = 1;
754 req->pages[0] = page;
85f40aec 755 req->page_descs[0].length = count;
e1c0eecb
MS		 756 init_sync_kiocb(&iocb, file);
757 io = (struct fuse_io_priv) FUSE_IO_PRIV_SYNC(&iocb);
36cf66ed 758 num_read = fuse_send_read(req, &io, pos, count, NULL);
b6aeaded 759 err = req->out.h.error;
5c5c5e51
MS		 760
761 if (!err) {
762 /*
763 * Short read means EOF. If file size is larger, truncate it
764 */
765 if (num_read < count)
a92adc82 766 fuse_short_read(req, inode, attr_ver);
5c5c5e51 767
b6aeaded 768 SetPageUptodate(page);
5c5c5e51
MS		 769 }
770
a92adc82 771 fuse_put_request(fc, req);
482fce55
MP		 772
773 return err;
774}
775
776static int fuse_readpage(struct file *file, struct page *page)
777{
778 struct inode *inode = page->mapping->host;
779 int err;
780
781 err = -EIO;
782 if (is_bad_inode(inode))
783 goto out;
784
785 err = fuse_do_readpage(file, page);
451418fc 786 fuse_invalidate_atime(inode);
b6aeaded
MS		 787 out:
788 unlock_page(page);
789 return err;
790}
791
c1aa96a5 792static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
db50b96c 793{
c1aa96a5 794 int i;
5c5c5e51
MS		 795 size_t count = req->misc.read.in.size;
796 size_t num_read = req->out.args[0].size;
ce534fb0 797 struct address_space *mapping = NULL;
c1aa96a5 798
ce534fb0
MS		 799 for (i = 0; mapping == NULL && i < req->num_pages; i++)
800 mapping = req->pages[i]->mapping;
5c5c5e51 801
ce534fb0
MS		 802 if (mapping) {
803 struct inode *inode = mapping->host;
804
805 /*
806 * Short read means EOF. If file size is larger, truncate it
807 */
a92adc82
PE		 808 if (!req->out.h.error && num_read < count)
809 fuse_short_read(req, inode, req->misc.read.attr_ver);
ce534fb0 810
451418fc 811 fuse_invalidate_atime(inode);
ce534fb0 812 }
c1aa96a5 813
db50b96c
MS		 814 for (i = 0; i < req->num_pages; i++) {
815 struct page *page = req->pages[i];
816 if (!req->out.h.error)
817 SetPageUptodate(page);
c1aa96a5
MS		 818 else
819 SetPageError(page);
db50b96c 820 unlock_page(page);
09cbfeaf 821 put_page(page);
db50b96c 822 }
c756e0a4 823 if (req->ff)
2e64ff15 824 fuse_file_put(req->ff, false, false);
c1aa96a5
MS		 825}
826
2106cb18 827static void fuse_send_readpages(struct fuse_req *req, struct file *file)
c1aa96a5 828{
2106cb18
MS		 829 struct fuse_file *ff = file->private_data;
830 struct fuse_conn *fc = ff->fc;
c1aa96a5 831 loff_t pos = page_offset(req->pages[0]);
09cbfeaf 832 size_t count = req->num_pages << PAGE_SHIFT;
f4975c67
MS		 833
834 req->out.argpages = 1;
c1aa96a5 835 req->out.page_zeroing = 1;
ce534fb0 836 req->out.page_replace = 1;
2106cb18 837 fuse_read_fill(req, file, pos, count, FUSE_READ);
5c5c5e51 838 req->misc.read.attr_ver = fuse_get_attr_version(fc);
9cd68455 839 if (fc->async_read) {
c756e0a4 840 req->ff = fuse_file_get(ff);
9cd68455 841 req->end = fuse_readpages_end;
b93f858a 842 fuse_request_send_background(fc, req);
9cd68455 843 } else {
b93f858a 844 fuse_request_send(fc, req);
9cd68455 845 fuse_readpages_end(fc, req);
e9bb09dd 846 fuse_put_request(fc, req);
9cd68455 847 }
db50b96c
MS		 848}
849
c756e0a4 850struct fuse_fill_data {
db50b96c 851 struct fuse_req *req;
a6643094 852 struct file *file;
db50b96c 853 struct inode *inode;
f8dbdf81 854 unsigned nr_pages;
db50b96c
MS		 855};
856
857static int fuse_readpages_fill(void *_data, struct page *page)
858{
c756e0a4 859 struct fuse_fill_data *data = _data;
db50b96c
MS		 860 struct fuse_req *req = data->req;
861 struct inode *inode = data->inode;
862 struct fuse_conn *fc = get_fuse_conn(inode);
863
3be5a52b
MS		 864 fuse_wait_on_page_writeback(inode, page->index);
865
db50b96c 866 if (req->num_pages &&
5da784cc 867 (req->num_pages == fc->max_pages ||
09cbfeaf 868 (req->num_pages + 1) * PAGE_SIZE > fc->max_read ||
db50b96c 869 req->pages[req->num_pages - 1]->index + 1 != page->index)) {
5da784cc
CS		 870 unsigned int nr_alloc = min_t(unsigned int, data->nr_pages,
871 fc->max_pages);
2106cb18 872 fuse_send_readpages(req, data->file);
8b41e671
MP		 873 if (fc->async_read)
874 req = fuse_get_req_for_background(fc, nr_alloc);
875 else
876 req = fuse_get_req(fc, nr_alloc);
877
878 data->req = req;
ce1d5a49 879 if (IS_ERR(req)) {
db50b96c 880 unlock_page(page);
ce1d5a49 881 return PTR_ERR(req);
db50b96c 882 }
db50b96c 883 }
f8dbdf81
MP		 884
885 if (WARN_ON(req->num_pages >= req->max_pages)) {
109728cc 886 unlock_page(page);
f8dbdf81
MP		 887 fuse_put_request(fc, req);
888 return -EIO;
889 }
890
09cbfeaf 891 get_page(page);
db50b96c 892 req->pages[req->num_pages] = page;
85f40aec 893 req->page_descs[req->num_pages].length = PAGE_SIZE;
1729a16c 894 req->num_pages++;
f8dbdf81 895 data->nr_pages--;
db50b96c
MS		 896 return 0;
897}
898
899static int fuse_readpages(struct file *file, struct address_space *mapping,
900 struct list_head *pages, unsigned nr_pages)
901{
902 struct inode *inode = mapping->host;
903 struct fuse_conn *fc = get_fuse_conn(inode);
c756e0a4 904 struct fuse_fill_data data;
db50b96c 905 int err;
5da784cc 906 unsigned int nr_alloc = min_t(unsigned int, nr_pages, fc->max_pages);
248d86e8 907
1d7ea732 908 err = -EIO;
248d86e8 909 if (is_bad_inode(inode))
2e990021 910 goto out;
248d86e8 911
a6643094 912 data.file = file;
db50b96c 913 data.inode = inode;
8b41e671
MP		 914 if (fc->async_read)
915 data.req = fuse_get_req_for_background(fc, nr_alloc);
916 else
917 data.req = fuse_get_req(fc, nr_alloc);
f8dbdf81 918 data.nr_pages = nr_pages;
1d7ea732 919 err = PTR_ERR(data.req);
ce1d5a49 920 if (IS_ERR(data.req))
2e990021 921 goto out;
db50b96c
MS		 922
923 err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
d3406ffa
MS		 924 if (!err) {
925 if (data.req->num_pages)
2106cb18 926 fuse_send_readpages(data.req, file);
d3406ffa
MS		 927 else
928 fuse_put_request(fc, data.req);
929 }
2e990021 930out:
1d7ea732 931 return err;
db50b96c
MS		 932}
933
55752a3a 934static ssize_t fuse_cache_read_iter(struct kiocb *iocb, struct iov_iter *to)
bcb4be80
MS		 935{
936 struct inode *inode = iocb->ki_filp->f_mapping->host;
a8894274 937 struct fuse_conn *fc = get_fuse_conn(inode);
bcb4be80 938
a8894274
BF		 939 /*
940 * In auto invalidate mode, always update attributes on read.
941 * Otherwise, only update if we attempt to read past EOF (to ensure
942 * i_size is up to date).
943 */
944 if (fc->auto_inval_data ||
37c20f16 945 (iocb->ki_pos + iov_iter_count(to) > i_size_read(inode))) {
bcb4be80 946 int err;
5b97eeac 947 err = fuse_update_attributes(inode, iocb->ki_filp);
bcb4be80
MS		 948 if (err)
949 return err;
950 }
951
37c20f16 952 return generic_file_read_iter(iocb, to);
bcb4be80
MS		 953}
954
2d698b07 955static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
2106cb18 956 loff_t pos, size_t count)
b6aeaded 957{
b25e82e5
MS		 958 struct fuse_write_in *inarg = &req->misc.write.in;
959 struct fuse_write_out *outarg = &req->misc.write.out;
b6aeaded 960
b25e82e5
MS		 961 inarg->fh = ff->fh;
962 inarg->offset = pos;
963 inarg->size = count;
b6aeaded 964 req->in.h.opcode = FUSE_WRITE;
2106cb18 965 req->in.h.nodeid = ff->nodeid;
b6aeaded 966 req->in.numargs = 2;
2106cb18 967 if (ff->fc->minor < 9)
f3332114
MS		 968 req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
969 else
970 req->in.args[0].size = sizeof(struct fuse_write_in);
b25e82e5 971 req->in.args[0].value = inarg;
b6aeaded
MS		 972 req->in.args[1].size = count;
973 req->out.numargs = 1;
974 req->out.args[0].size = sizeof(struct fuse_write_out);
b25e82e5
MS		 975 req->out.args[0].value = outarg;
976}
977
36cf66ed 978static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
2106cb18 979 loff_t pos, size_t count, fl_owner_t owner)
b25e82e5 980{
e1c0eecb
MS		 981 struct kiocb *iocb = io->iocb;
982 struct file *file = iocb->ki_filp;
2106cb18
MS		 983 struct fuse_file *ff = file->private_data;
984 struct fuse_conn *fc = ff->fc;
2d698b07
MS		 985 struct fuse_write_in *inarg = &req->misc.write.in;
986
2106cb18 987 fuse_write_fill(req, ff, pos, count);
2d698b07 988 inarg->flags = file->f_flags;
e1c0eecb
MS		 989 if (iocb->ki_flags & IOCB_DSYNC)
990 inarg->flags |= O_DSYNC;
991 if (iocb->ki_flags & IOCB_SYNC)
992 inarg->flags |= O_SYNC;
f3332114 993 if (owner != NULL) {
f3332114
MS		 994 inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
995 inarg->lock_owner = fuse_lock_owner_id(fc, owner);
996 }
36cf66ed
MP		 997
998 if (io->async)
999 return fuse_async_req_send(fc, req, count, io);
1000
b93f858a 1001 fuse_request_send(fc, req);
b25e82e5 1002 return req->misc.write.out.size;
b6aeaded
MS		 1003}
1004
b0aa7606 1005bool fuse_write_update_size(struct inode *inode, loff_t pos)
854512ec
MS		 1006{
1007 struct fuse_conn *fc = get_fuse_conn(inode);
1008 struct fuse_inode *fi = get_fuse_inode(inode);
b0aa7606 1009 bool ret = false;
854512ec 1010
f15ecfef 1011 spin_lock(&fi->lock);
4510d86f 1012 fi->attr_version = atomic64_inc_return(&fc->attr_version);
b0aa7606 1013 if (pos > inode->i_size) {
854512ec 1014 i_size_write(inode, pos);
b0aa7606
MP		 1015 ret = true;
1016 }
f15ecfef 1017 spin_unlock(&fi->lock);
b0aa7606
MP		 1018
1019 return ret;
854512ec
MS		 1020}
1021
e1c0eecb 1022static size_t fuse_send_write_pages(struct fuse_req *req, struct kiocb *iocb,
ea9b9907
NP		 1023 struct inode *inode, loff_t pos,
1024 size_t count)
1025{
1026 size_t res;
1027 unsigned offset;
1028 unsigned i;
e1c0eecb 1029 struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
ea9b9907
NP		 1030
1031 for (i = 0; i < req->num_pages; i++)
1032 fuse_wait_on_page_writeback(inode, req->pages[i]->index);
1033
36cf66ed 1034 res = fuse_send_write(req, &io, pos, count, NULL);
ea9b9907 1035
b2430d75 1036 offset = req->page_descs[0].offset;
ea9b9907
NP		 1037 count = res;
1038 for (i = 0; i < req->num_pages; i++) {
1039 struct page *page = req->pages[i];
1040
09cbfeaf 1041 if (!req->out.h.error && !offset && count >= PAGE_SIZE)
ea9b9907
NP		 1042 SetPageUptodate(page);
1043
09cbfeaf
KS		 1044 if (count > PAGE_SIZE - offset)
1045 count -= PAGE_SIZE - offset;
ea9b9907
NP		 1046 else
1047 count = 0;
1048 offset = 0;
1049
1050 unlock_page(page);
09cbfeaf 1051 put_page(page);
ea9b9907
NP		 1052 }
1053
1054 return res;
1055}
1056
1057static ssize_t fuse_fill_write_pages(struct fuse_req *req,
1058 struct address_space *mapping,
1059 struct iov_iter *ii, loff_t pos)
1060{
1061 struct fuse_conn *fc = get_fuse_conn(mapping->host);
09cbfeaf 1062 unsigned offset = pos & (PAGE_SIZE - 1);
ea9b9907
NP		 1063 size_t count = 0;
1064 int err;
1065
f4975c67 1066 req->in.argpages = 1;
b2430d75 1067 req->page_descs[0].offset = offset;
ea9b9907
NP		 1068
1069 do {
1070 size_t tmp;
1071 struct page *page;
09cbfeaf
KS		 1072 pgoff_t index = pos >> PAGE_SHIFT;
1073 size_t bytes = min_t(size_t, PAGE_SIZE - offset,
ea9b9907
NP		 1074 iov_iter_count(ii));
1075
1076 bytes = min_t(size_t, bytes, fc->max_write - count);
1077
1078 again:
1079 err = -EFAULT;
1080 if (iov_iter_fault_in_readable(ii, bytes))
1081 break;
1082
1083 err = -ENOMEM;
54566b2c 1084 page = grab_cache_page_write_begin(mapping, index, 0);
ea9b9907
NP		 1085 if (!page)
1086 break;
1087
931e80e4 1088 if (mapping_writably_mapped(mapping))
1089 flush_dcache_page(page);
1090
ea9b9907 1091 tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
ea9b9907
NP		 1092 flush_dcache_page(page);
1093
3ca8138f 1094 iov_iter_advance(ii, tmp);
ea9b9907
NP		 1095 if (!tmp) {
1096 unlock_page(page);
09cbfeaf 1097 put_page(page);
ea9b9907
NP		 1098 bytes = min(bytes, iov_iter_single_seg_count(ii));
1099 goto again;
1100 }
1101
1102 err = 0;
1103 req->pages[req->num_pages] = page;
85f40aec 1104 req->page_descs[req->num_pages].length = tmp;
ea9b9907
NP		 1105 req->num_pages++;
1106
ea9b9907
NP		 1107 count += tmp;
1108 pos += tmp;
1109 offset += tmp;
09cbfeaf 1110 if (offset == PAGE_SIZE)
ea9b9907
NP		 1111 offset = 0;
1112
78bb6cb9
MS		 1113 if (!fc->big_writes)
1114 break;
ea9b9907 1115 } while (iov_iter_count(ii) && count < fc->max_write &&
d07f09f5 1116 req->num_pages < req->max_pages && offset == 0);
ea9b9907
NP		 1117
1118 return count > 0 ? count : err;
1119}
1120
5da784cc
CS		 1121static inline unsigned int fuse_wr_pages(loff_t pos, size_t len,
1122 unsigned int max_pages)
d07f09f5 1123{
5da784cc 1124 return min_t(unsigned int,
09cbfeaf
KS		 1125 ((pos + len - 1) >> PAGE_SHIFT) -
1126 (pos >> PAGE_SHIFT) + 1,
5da784cc 1127 max_pages);
d07f09f5
MP		 1128}
1129
e1c0eecb 1130static ssize_t fuse_perform_write(struct kiocb *iocb,
ea9b9907
NP		 1131 struct address_space *mapping,
1132 struct iov_iter *ii, loff_t pos)
1133{
1134 struct inode *inode = mapping->host;
1135 struct fuse_conn *fc = get_fuse_conn(inode);
06a7c3c2 1136 struct fuse_inode *fi = get_fuse_inode(inode);
ea9b9907
NP		 1137 int err = 0;
1138 ssize_t res = 0;
1139
06a7c3c2
MP		 1140 if (inode->i_size < pos + iov_iter_count(ii))
1141 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1142
ea9b9907
NP		 1143 do {
1144 struct fuse_req *req;
1145 ssize_t count;
5da784cc
CS		 1146 unsigned int nr_pages = fuse_wr_pages(pos, iov_iter_count(ii),
1147 fc->max_pages);
ea9b9907 1148
d07f09f5 1149 req = fuse_get_req(fc, nr_pages);
ea9b9907
NP		 1150 if (IS_ERR(req)) {
1151 err = PTR_ERR(req);
1152 break;
1153 }
1154
1155 count = fuse_fill_write_pages(req, mapping, ii, pos);
1156 if (count <= 0) {
1157 err = count;
1158 } else {
1159 size_t num_written;
1160
e1c0eecb 1161 num_written = fuse_send_write_pages(req, iocb, inode,
ea9b9907
NP		 1162 pos, count);
1163 err = req->out.h.error;
1164 if (!err) {
1165 res += num_written;
1166 pos += num_written;
1167
1168 /* break out of the loop on short write */
1169 if (num_written != count)
1170 err = -EIO;
1171 }
1172 }
1173 fuse_put_request(fc, req);
1174 } while (!err && iov_iter_count(ii));
1175
1176 if (res > 0)
1177 fuse_write_update_size(inode, pos);
1178
06a7c3c2 1179 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
ea9b9907
NP		 1180 fuse_invalidate_attr(inode);
1181
1182 return res > 0 ? res : err;
1183}
1184
55752a3a 1185static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
ea9b9907
NP		 1186{
1187 struct file *file = iocb->ki_filp;
1188 struct address_space *mapping = file->f_mapping;
ea9b9907 1189 ssize_t written = 0;
4273b793 1190 ssize_t written_buffered = 0;
ea9b9907
NP		 1191 struct inode *inode = mapping->host;
1192 ssize_t err;
4273b793 1193 loff_t endbyte = 0;
ea9b9907 1194
4d99ff8f
PE		 1195 if (get_fuse_conn(inode)->writeback_cache) {
1196 /* Update size (EOF optimization) and mode (SUID clearing) */
5b97eeac 1197 err = fuse_update_attributes(mapping->host, file);
4d99ff8f
PE		 1198 if (err)
1199 return err;
1200
84c3d55c 1201 return generic_file_write_iter(iocb, from);
4d99ff8f
PE		 1202 }
1203
5955102c 1204 inode_lock(inode);
ea9b9907
NP		 1205
1206 /* We can write back this queue in page reclaim */
de1414a6 1207 current->backing_dev_info = inode_to_bdi(inode);
ea9b9907 1208
3309dd04
AV		 1209 err = generic_write_checks(iocb, from);
1210 if (err <= 0)
ea9b9907
NP		 1211 goto out;
1212
5fa8e0a1 1213 err = file_remove_privs(file);
ea9b9907
NP		 1214 if (err)
1215 goto out;
1216
c3b2da31
JB		 1217 err = file_update_time(file);
1218 if (err)
1219 goto out;
ea9b9907 1220
2ba48ce5 1221 if (iocb->ki_flags & IOCB_DIRECT) {
3309dd04 1222 loff_t pos = iocb->ki_pos;
1af5bb49 1223 written = generic_file_direct_write(iocb, from);
84c3d55c 1224 if (written < 0 || !iov_iter_count(from))
4273b793
AA		 1225 goto out;
1226
1227 pos += written;
ea9b9907 1228
e1c0eecb 1229 written_buffered = fuse_perform_write(iocb, mapping, from, pos);
4273b793
AA		 1230 if (written_buffered < 0) {
1231 err = written_buffered;
1232 goto out;
1233 }
1234 endbyte = pos + written_buffered - 1;
1235
1236 err = filemap_write_and_wait_range(file->f_mapping, pos,
1237 endbyte);
1238 if (err)
1239 goto out;
1240
1241 invalidate_mapping_pages(file->f_mapping,
09cbfeaf
KS		 1242 pos >> PAGE_SHIFT,
1243 endbyte >> PAGE_SHIFT);
4273b793
AA		 1244
1245 written += written_buffered;
1246 iocb->ki_pos = pos + written_buffered;
1247 } else {
e1c0eecb 1248 written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos);
4273b793 1249 if (written >= 0)
3309dd04 1250 iocb->ki_pos += written;
4273b793 1251 }
ea9b9907
NP		 1252out:
1253 current->backing_dev_info = NULL;
5955102c 1254 inode_unlock(inode);
e1c0eecb
MS		 1255 if (written > 0)
1256 written = generic_write_sync(iocb, written);
ea9b9907
NP		 1257
1258 return written ? written : err;
1259}
1260
7c190c8b
MP		 1261static inline void fuse_page_descs_length_init(struct fuse_req *req,
1262 unsigned index, unsigned nr_pages)
85f40aec
MP		 1263{
1264 int i;
1265
7c190c8b 1266 for (i = index; i < index + nr_pages; i++)
85f40aec
MP		 1267 req->page_descs[i].length = PAGE_SIZE -
1268 req->page_descs[i].offset;
1269}
1270
7c190c8b
MP		 1271static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
1272{
1273 return (unsigned long)ii->iov->iov_base + ii->iov_offset;
1274}
1275
1276static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
1277 size_t max_size)
1278{
1279 return min(iov_iter_single_seg_count(ii), max_size);
1280}
1281
b98d023a 1282static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
ce60a2f1 1283 size_t *nbytesp, int write)
413ef8cb 1284{
7c190c8b 1285 size_t nbytes = 0; /* # bytes already packed in req */
742f9927 1286 ssize_t ret = 0;
b98d023a 1287
f4975c67 1288 /* Special case for kernel I/O: can copy directly into the buffer */
00e23707 1289 if (iov_iter_is_kvec(ii)) {
7c190c8b
MP		 1290 unsigned long user_addr = fuse_get_user_addr(ii);
1291 size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
1292
f4975c67
MS		 1293 if (write)
1294 req->in.args[1].value = (void *) user_addr;
1295 else
1296 req->out.args[0].value = (void *) user_addr;
1297
b98d023a
MP		 1298 iov_iter_advance(ii, frag_size);
1299 *nbytesp = frag_size;
f4975c67
MS		 1300 return 0;
1301 }
413ef8cb 1302
5565a9d8 1303 while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
7c190c8b 1304 unsigned npages;
f67da30c 1305 size_t start;
742f9927 1306 ret = iov_iter_get_pages(ii, &req->pages[req->num_pages],
2c80929c 1307 *nbytesp - nbytes,
c7f3888a
AV		 1308 req->max_pages - req->num_pages,
1309 &start);
7c190c8b 1310 if (ret < 0)
742f9927 1311 break;
7c190c8b 1312
c9c37e2e
AV		 1313 iov_iter_advance(ii, ret);
1314 nbytes += ret;
7c190c8b 1315
c9c37e2e
AV		 1316 ret += start;
1317 npages = (ret + PAGE_SIZE - 1) / PAGE_SIZE;
7c190c8b 1318
c9c37e2e 1319 req->page_descs[req->num_pages].offset = start;
7c190c8b
MP		 1320 fuse_page_descs_length_init(req, req->num_pages, npages);
1321
1322 req->num_pages += npages;
1323 req->page_descs[req->num_pages - 1].length -=
c9c37e2e 1324 (PAGE_SIZE - ret) & (PAGE_SIZE - 1);
7c190c8b 1325 }
f4975c67
MS		 1326
1327 if (write)
1328 req->in.argpages = 1;
1329 else
1330 req->out.argpages = 1;
1331
7c190c8b 1332 *nbytesp = nbytes;
f4975c67 1333
2c932d4c 1334 return ret < 0 ? ret : 0;
413ef8cb
MS		 1335}
1336
d22a943f
AV		 1337ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1338 loff_t *ppos, int flags)
413ef8cb 1339{
ea8cd333
PE		 1340 int write = flags & FUSE_DIO_WRITE;
1341 int cuse = flags & FUSE_DIO_CUSE;
e1c0eecb 1342 struct file *file = io->iocb->ki_filp;
ea8cd333 1343 struct inode *inode = file->f_mapping->host;
2106cb18
MS		 1344 struct fuse_file *ff = file->private_data;
1345 struct fuse_conn *fc = ff->fc;
413ef8cb
MS		 1346 size_t nmax = write ? fc->max_write : fc->max_read;
1347 loff_t pos = *ppos;
d22a943f 1348 size_t count = iov_iter_count(iter);
09cbfeaf
KS		 1349 pgoff_t idx_from = pos >> PAGE_SHIFT;
1350 pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT;
413ef8cb 1351 ssize_t res = 0;
248d86e8 1352 struct fuse_req *req;
742f9927 1353 int err = 0;
248d86e8 1354
de82b923 1355 if (io->async)
5da784cc
CS		 1356 req = fuse_get_req_for_background(fc, iov_iter_npages(iter,
1357 fc->max_pages));
de82b923 1358 else
5da784cc 1359 req = fuse_get_req(fc, iov_iter_npages(iter, fc->max_pages));
ce1d5a49
MS		 1360 if (IS_ERR(req))
1361 return PTR_ERR(req);
413ef8cb 1362
ea8cd333
PE		 1363 if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
1364 if (!write)
5955102c 1365 inode_lock(inode);
ea8cd333
PE		 1366 fuse_sync_writes(inode);
1367 if (!write)
5955102c 1368 inode_unlock(inode);
ea8cd333
PE		 1369 }
1370
61c12b49 1371 io->should_dirty = !write && iter_is_iovec(iter);
413ef8cb 1372 while (count) {
413ef8cb 1373 size_t nres;
2106cb18 1374 fl_owner_t owner = current->files;
f4975c67 1375 size_t nbytes = min(count, nmax);
742f9927
AS		 1376 err = fuse_get_user_pages(req, iter, &nbytes, write);
1377 if (err && !nbytes)
413ef8cb 1378 break;
f4975c67 1379
4a2abf99
MS		 1380 if (write) {
1381 if (!capable(CAP_FSETID)) {
1382 struct fuse_write_in *inarg;
1383
1384 inarg = &req->misc.write.in;
1385 inarg->write_flags |= FUSE_WRITE_KILL_PRIV;
1386 }
36cf66ed 1387 nres = fuse_send_write(req, io, pos, nbytes, owner);
4a2abf99 1388 } else {
36cf66ed 1389 nres = fuse_send_read(req, io, pos, nbytes, owner);
4a2abf99 1390 }
2106cb18 1391
36cf66ed 1392 if (!io->async)
61c12b49 1393 fuse_release_user_pages(req, io->should_dirty);
413ef8cb 1394 if (req->out.h.error) {
742f9927 1395 err = req->out.h.error;
413ef8cb
MS		 1396 break;
1397 } else if (nres > nbytes) {
742f9927
AS		 1398 res = 0;
1399 err = -EIO;
413ef8cb
MS		 1400 break;
1401 }
1402 count -= nres;
1403 res += nres;
1404 pos += nres;
413ef8cb
MS		 1405 if (nres != nbytes)
1406 break;
56cf34ff
MS		 1407 if (count) {
1408 fuse_put_request(fc, req);
de82b923
BF		 1409 if (io->async)
1410 req = fuse_get_req_for_background(fc,
5da784cc 1411 iov_iter_npages(iter, fc->max_pages));
de82b923 1412 else
5da784cc
CS		 1413 req = fuse_get_req(fc, iov_iter_npages(iter,
1414 fc->max_pages));
56cf34ff
MS		 1415 if (IS_ERR(req))
1416 break;
1417 }
413ef8cb 1418 }
f60311d5
AA		 1419 if (!IS_ERR(req))
1420 fuse_put_request(fc, req);
d09cb9d7 1421 if (res > 0)
413ef8cb 1422 *ppos = pos;
413ef8cb 1423
742f9927 1424 return res > 0 ? res : err;
413ef8cb 1425}
08cbf542 1426EXPORT_SYMBOL_GPL(fuse_direct_io);
413ef8cb 1427
36cf66ed 1428static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
d22a943f
AV		 1429 struct iov_iter *iter,
1430 loff_t *ppos)
413ef8cb 1431{
d09cb9d7 1432 ssize_t res;
e1c0eecb 1433 struct inode *inode = file_inode(io->iocb->ki_filp);
d09cb9d7 1434
d22a943f 1435 res = fuse_direct_io(io, iter, ppos, 0);
d09cb9d7 1436
9a2eb24d 1437 fuse_invalidate_atime(inode);
d09cb9d7
MS		 1438
1439 return res;
413ef8cb
MS		 1440}
1441
23c94e1c
MR		 1442static ssize_t fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
1443
15316263 1444static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
b98d023a 1445{
23c94e1c
MR		 1446 ssize_t res;
1447
1448 if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
23c94e1c
MR		 1449 res = fuse_direct_IO(iocb, to);
1450 } else {
1451 struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
1452
1453 res = __fuse_direct_read(&io, to, &iocb->ki_pos);
1454 }
1455
1456 return res;
b98d023a
MP		 1457}
1458
15316263 1459static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
4273b793 1460{
e1c0eecb
MS		 1461 struct inode *inode = file_inode(iocb->ki_filp);
1462 struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
15316263 1463 ssize_t res;
4273b793 1464
4273b793 1465 /* Don't allow parallel writes to the same file */
5955102c 1466 inode_lock(inode);
3309dd04 1467 res = generic_write_checks(iocb, from);
23c94e1c
MR		 1468 if (res > 0) {
1469 if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
1470 res = fuse_direct_IO(iocb, from);
1471 } else {
1472 res = fuse_direct_io(&io, from, &iocb->ki_pos,
1473 FUSE_DIO_WRITE);
1474 }
1475 }
812408fb 1476 fuse_invalidate_attr(inode);
bcba24cc 1477 if (res > 0)
15316263 1478 fuse_write_update_size(inode, iocb->ki_pos);
5955102c 1479 inode_unlock(inode);
4273b793
AA		 1480
1481 return res;
1482}
1483
55752a3a
MS		 1484static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
1485{
2f7b6f5b
MS		 1486 struct file *file = iocb->ki_filp;
1487 struct fuse_file *ff = file->private_data;
1488
1489 if (is_bad_inode(file_inode(file)))
1490 return -EIO;
55752a3a
MS		 1491
1492 if (!(ff->open_flags & FOPEN_DIRECT_IO))
1493 return fuse_cache_read_iter(iocb, to);
1494 else
1495 return fuse_direct_read_iter(iocb, to);
1496}
1497
1498static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1499{
2f7b6f5b
MS		 1500 struct file *file = iocb->ki_filp;
1501 struct fuse_file *ff = file->private_data;
1502
1503 if (is_bad_inode(file_inode(file)))
1504 return -EIO;
55752a3a
MS		 1505
1506 if (!(ff->open_flags & FOPEN_DIRECT_IO))
1507 return fuse_cache_write_iter(iocb, from);
1508 else
1509 return fuse_direct_write_iter(iocb, from);
1510}
1511
3be5a52b 1512static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
b6aeaded 1513{
385b1268
PE		 1514 int i;
1515
1516 for (i = 0; i < req->num_pages; i++)
1517 __free_page(req->pages[i]);
8b284dc4
MS		 1518
1519 if (req->ff)
2e64ff15 1520 fuse_file_put(req->ff, false, false);
3be5a52b
MS		 1521}
1522
1523static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
1524{
1525 struct inode *inode = req->inode;
1526 struct fuse_inode *fi = get_fuse_inode(inode);
de1414a6 1527 struct backing_dev_info *bdi = inode_to_bdi(inode);
385b1268 1528 int i;
3be5a52b
MS		 1529
1530 list_del(&req->writepages_entry);
385b1268 1531 for (i = 0; i < req->num_pages; i++) {
93f78d88 1532 dec_wb_stat(&bdi->wb, WB_WRITEBACK);
11fb9989 1533 dec_node_page_state(req->pages[i], NR_WRITEBACK_TEMP);
93f78d88 1534 wb_writeout_inc(&bdi->wb);
385b1268 1535 }
3be5a52b
MS		 1536 wake_up(&fi->page_waitq);
1537}
1538
f15ecfef 1539/* Called under fi->lock, may release and reacquire it */
6eaf4782
MP		 1540static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req,
1541 loff_t size)
f15ecfef
KT		 1542__releases(fi->lock)
1543__acquires(fi->lock)
3be5a52b 1544{
e2653bd5 1545 struct fuse_req *aux, *next;
3be5a52b 1546 struct fuse_inode *fi = get_fuse_inode(req->inode);
3be5a52b 1547 struct fuse_write_in *inarg = &req->misc.write.in;
09cbfeaf 1548 __u64 data_size = req->num_pages * PAGE_SIZE;
63825b4e 1549 bool queued;
3be5a52b 1550
385b1268
PE		 1551 if (inarg->offset + data_size <= size) {
1552 inarg->size = data_size;
3be5a52b 1553 } else if (inarg->offset < size) {
385b1268 1554 inarg->size = size - inarg->offset;
3be5a52b
MS		 1555 } else {
1556 /* Got truncated off completely */
1557 goto out_free;
b6aeaded 1558 }
3be5a52b
MS		 1559
1560 req->in.args[1].size = inarg->size;
63825b4e 1561 queued = fuse_request_queue_background(fc, req);
f15ecfef
KT		 1562 /* Fails on broken connection only */
1563 if (unlikely(!queued))
1564 goto out_free;
1565
1566 fi->writectr++;
3be5a52b
MS		 1567 return;
1568
1569 out_free:
1570 fuse_writepage_finish(fc, req);
f15ecfef 1571 spin_unlock(&fi->lock);
e2653bd5
MS		 1572
1573 /* After fuse_writepage_finish() aux request list is private */
1574 for (aux = req->misc.write.next; aux; aux = next) {
1575 next = aux->misc.write.next;
1576 aux->misc.write.next = NULL;
1577 fuse_writepage_free(fc, aux);
1578 fuse_put_request(fc, aux);
1579 }
1580
3be5a52b 1581 fuse_writepage_free(fc, req);
e9bb09dd 1582 fuse_put_request(fc, req);
f15ecfef 1583 spin_lock(&fi->lock);
b6aeaded
MS		 1584}
1585
3be5a52b
MS		 1586/*
1587 * If fi->writectr is positive (no truncate or fsync going on) send
1588 * all queued writepage requests.
1589 *
f15ecfef 1590 * Called with fi->lock
3be5a52b
MS		 1591 */
1592void fuse_flush_writepages(struct inode *inode)
f15ecfef
KT		 1593__releases(fi->lock)
1594__acquires(fi->lock)
b6aeaded 1595{
3be5a52b
MS		 1596 struct fuse_conn *fc = get_fuse_conn(inode);
1597 struct fuse_inode *fi = get_fuse_inode(inode);
9de5be06 1598 loff_t crop = i_size_read(inode);
3be5a52b
MS		 1599 struct fuse_req *req;
1600
1601 while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
1602 req = list_entry(fi->queued_writes.next, struct fuse_req, list);
1603 list_del_init(&req->list);
6eaf4782 1604 fuse_send_writepage(fc, req, crop);
3be5a52b
MS		 1605 }
1606}
1607
1608static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
1609{
1610 struct inode *inode = req->inode;
1611 struct fuse_inode *fi = get_fuse_inode(inode);
1612
1613 mapping_set_error(inode->i_mapping, req->out.h.error);
f15ecfef 1614 spin_lock(&fi->lock);
8b284dc4 1615 while (req->misc.write.next) {
6eaf4782
MP		 1616 struct fuse_conn *fc = get_fuse_conn(inode);
1617 struct fuse_write_in *inarg = &req->misc.write.in;
8b284dc4
MS		 1618 struct fuse_req *next = req->misc.write.next;
1619 req->misc.write.next = next->misc.write.next;
1620 next->misc.write.next = NULL;
ce128de6 1621 next->ff = fuse_file_get(req->ff);
8b284dc4 1622 list_add(&next->writepages_entry, &fi->writepages);
6eaf4782
MP		 1623
1624 /*
1625 * Skip fuse_flush_writepages() to make it easy to crop requests
1626 * based on primary request size.
1627 *
1628 * 1st case (trivial): there are no concurrent activities using
1629 * fuse_set/release_nowrite. Then we're on safe side because
1630 * fuse_flush_writepages() would call fuse_send_writepage()
1631 * anyway.
1632 *
1633 * 2nd case: someone called fuse_set_nowrite and it is waiting
1634 * now for completion of all in-flight requests. This happens
1635 * rarely and no more than once per page, so this should be
1636 * okay.
1637 *
1638 * 3rd case: someone (e.g. fuse_do_setattr()) is in the middle
1639 * of fuse_set_nowrite..fuse_release_nowrite section. The fact
1640 * that fuse_set_nowrite returned implies that all in-flight
1641 * requests were completed along with all of their secondary
1642 * requests. Further primary requests are blocked by negative
1643 * writectr. Hence there cannot be any in-flight requests and
1644 * no invocations of fuse_writepage_end() while we're in
1645 * fuse_set_nowrite..fuse_release_nowrite section.
1646 */
1647 fuse_send_writepage(fc, next, inarg->offset + inarg->size);
8b284dc4 1648 }
3be5a52b
MS		 1649 fi->writectr--;
1650 fuse_writepage_finish(fc, req);
f15ecfef 1651 spin_unlock(&fi->lock);
3be5a52b
MS		 1652 fuse_writepage_free(fc, req);
1653}
1654
1e18bda8
MS		 1655static struct fuse_file *__fuse_write_file_get(struct fuse_conn *fc,
1656 struct fuse_inode *fi)
adcadfa8 1657{
72523425 1658 struct fuse_file *ff = NULL;
adcadfa8 1659
f15ecfef 1660 spin_lock(&fi->lock);
1e18bda8 1661 if (!list_empty(&fi->write_files)) {
72523425
MS		 1662 ff = list_entry(fi->write_files.next, struct fuse_file,
1663 write_entry);
1664 fuse_file_get(ff);
1665 }
f15ecfef 1666 spin_unlock(&fi->lock);
adcadfa8
PE		 1667
1668 return ff;
1669}
1670
1e18bda8
MS		 1671static struct fuse_file *fuse_write_file_get(struct fuse_conn *fc,
1672 struct fuse_inode *fi)
1673{
1674 struct fuse_file *ff = __fuse_write_file_get(fc, fi);
1675 WARN_ON(!ff);
1676 return ff;
1677}
1678
1679int fuse_write_inode(struct inode *inode, struct writeback_control *wbc)
1680{
1681 struct fuse_conn *fc = get_fuse_conn(inode);
1682 struct fuse_inode *fi = get_fuse_inode(inode);
1683 struct fuse_file *ff;
1684 int err;
1685
1686 ff = __fuse_write_file_get(fc, fi);
ab9e13f7 1687 err = fuse_flush_times(inode, ff);
1e18bda8 1688 if (ff)
2e64ff15 1689 fuse_file_put(ff, false, false);
1e18bda8
MS		 1690
1691 return err;
1692}
1693
3be5a52b
MS		 1694static int fuse_writepage_locked(struct page *page)
1695{
1696 struct address_space *mapping = page->mapping;
1697 struct inode *inode = mapping->host;
1698 struct fuse_conn *fc = get_fuse_conn(inode);
1699 struct fuse_inode *fi = get_fuse_inode(inode);
1700 struct fuse_req *req;
3be5a52b 1701 struct page *tmp_page;
72523425 1702 int error = -ENOMEM;
3be5a52b
MS		 1703
1704 set_page_writeback(page);
1705
4250c066 1706 req = fuse_request_alloc_nofs(1);
3be5a52b
MS		 1707 if (!req)
1708 goto err;
1709
825d6d33
MS		 1710 /* writeback always goes to bg_queue */
1711 __set_bit(FR_BACKGROUND, &req->flags);
3be5a52b
MS		 1712 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1713 if (!tmp_page)
1714 goto err_free;
1715
72523425 1716 error = -EIO;
26d614df 1717 req->ff = fuse_write_file_get(fc, fi);
72523425 1718 if (!req->ff)
27f1b363 1719 goto err_nofile;
72523425 1720
adcadfa8 1721 fuse_write_fill(req, req->ff, page_offset(page), 0);
3be5a52b
MS		 1722
1723 copy_highpage(tmp_page, page);
2d698b07 1724 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
8b284dc4 1725 req->misc.write.next = NULL;
f4975c67 1726 req->in.argpages = 1;
3be5a52b
MS		 1727 req->num_pages = 1;
1728 req->pages[0] = tmp_page;
b2430d75 1729 req->page_descs[0].offset = 0;
85f40aec 1730 req->page_descs[0].length = PAGE_SIZE;
3be5a52b
MS		 1731 req->end = fuse_writepage_end;
1732 req->inode = inode;
1733
93f78d88 1734 inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
11fb9989 1735 inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP);
3be5a52b 1736
f15ecfef 1737 spin_lock(&fi->lock);
3be5a52b
MS		 1738 list_add(&req->writepages_entry, &fi->writepages);
1739 list_add_tail(&req->list, &fi->queued_writes);
1740 fuse_flush_writepages(inode);
f15ecfef 1741 spin_unlock(&fi->lock);
3be5a52b 1742
4a4ac4eb
MP		 1743 end_page_writeback(page);
1744
3be5a52b
MS		 1745 return 0;
1746
27f1b363
MP		 1747err_nofile:
1748 __free_page(tmp_page);
3be5a52b
MS		 1749err_free:
1750 fuse_request_free(req);
1751err:
9183976e 1752 mapping_set_error(page->mapping, error);
3be5a52b 1753 end_page_writeback(page);
72523425 1754 return error;
3be5a52b
MS		 1755}
1756
1757static int fuse_writepage(struct page *page, struct writeback_control *wbc)
1758{
1759 int err;
1760
ff17be08
MS		 1761 if (fuse_page_is_writeback(page->mapping->host, page->index)) {
1762 /*
1763 * ->writepages() should be called for sync() and friends. We
1764 * should only get here on direct reclaim and then we are
1765 * allowed to skip a page which is already in flight
1766 */
1767 WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
1768
1769 redirty_page_for_writepage(wbc, page);
1770 return 0;
1771 }
1772
3be5a52b
MS		 1773 err = fuse_writepage_locked(page);
1774 unlock_page(page);
1775
1776 return err;
1777}
1778
26d614df
PE		 1779struct fuse_fill_wb_data {
1780 struct fuse_req *req;
1781 struct fuse_file *ff;
1782 struct inode *inode;
2d033eaa 1783 struct page **orig_pages;
26d614df
PE		 1784};
1785
1786static void fuse_writepages_send(struct fuse_fill_wb_data *data)
1787{
1788 struct fuse_req *req = data->req;
1789 struct inode *inode = data->inode;
26d614df 1790 struct fuse_inode *fi = get_fuse_inode(inode);
2d033eaa
MP		 1791 int num_pages = req->num_pages;
1792 int i;
26d614df
PE		 1793
1794 req->ff = fuse_file_get(data->ff);
f15ecfef 1795 spin_lock(&fi->lock);
26d614df
PE		 1796 list_add_tail(&req->list, &fi->queued_writes);
1797 fuse_flush_writepages(inode);
f15ecfef 1798 spin_unlock(&fi->lock);
2d033eaa
MP		 1799
1800 for (i = 0; i < num_pages; i++)
1801 end_page_writeback(data->orig_pages[i]);
26d614df
PE		 1802}
1803
7f305ca1
MS		 1804/*
1805 * First recheck under fi->lock if the offending offset is still under
419234d5
MS		 1806 * writeback. If yes, then iterate auxiliary write requests, to see if there's
1807 * one already added for a page at this offset. If there's none, then insert
1808 * this new request onto the auxiliary list, otherwise reuse the existing one by
7f305ca1
MS		 1809 * copying the new page contents over to the old temporary page.
1810 */
8b284dc4
MS		 1811static bool fuse_writepage_in_flight(struct fuse_req *new_req,
1812 struct page *page)
1813{
1814 struct fuse_conn *fc = get_fuse_conn(new_req->inode);
1815 struct fuse_inode *fi = get_fuse_inode(new_req->inode);
1816 struct fuse_req *tmp;
1817 struct fuse_req *old_req;
8b284dc4 1818
7f305ca1 1819 WARN_ON(new_req->num_pages != 0);
8b284dc4 1820
f15ecfef 1821 spin_lock(&fi->lock);
8b284dc4 1822 list_del(&new_req->writepages_entry);
2fe93bd4
MS		 1823 old_req = fuse_find_writeback(fi, page->index, page->index);
1824 if (!old_req) {
f6011081 1825 list_add(&new_req->writepages_entry, &fi->writepages);
f15ecfef 1826 spin_unlock(&fi->lock);
2fe93bd4 1827 return false;
f6011081 1828 }
8b284dc4 1829
f6011081 1830 new_req->num_pages = 1;
419234d5 1831 for (tmp = old_req->misc.write.next; tmp; tmp = tmp->misc.write.next) {
7f305ca1
MS		 1832 pgoff_t curr_index;
1833
1834 WARN_ON(tmp->inode != new_req->inode);
09cbfeaf 1835 curr_index = tmp->misc.write.in.offset >> PAGE_SHIFT;
419234d5
MS		 1836 if (curr_index == page->index) {
1837 WARN_ON(tmp->num_pages != 1);
1838 WARN_ON(!test_bit(FR_PENDING, &tmp->flags));
c5de16cc 1839 swap(tmp->pages[0], new_req->pages[0]);
7f305ca1 1840 break;
8b284dc4
MS		 1841 }
1842 }
1843
7f305ca1
MS		 1844 if (!tmp) {
1845 new_req->misc.write.next = old_req->misc.write.next;
1846 old_req->misc.write.next = new_req;
1847 }
41b6e41f 1848
f15ecfef 1849 spin_unlock(&fi->lock);
7f305ca1
MS		 1850
1851 if (tmp) {
1852 struct backing_dev_info *bdi = inode_to_bdi(new_req->inode);
8b284dc4 1853
93f78d88 1854 dec_wb_stat(&bdi->wb, WB_WRITEBACK);
a2ebba82 1855 dec_node_page_state(new_req->pages[0], NR_WRITEBACK_TEMP);
93f78d88 1856 wb_writeout_inc(&bdi->wb);
8b284dc4
MS		 1857 fuse_writepage_free(fc, new_req);
1858 fuse_request_free(new_req);
8b284dc4 1859 }
7f305ca1 1860
2fe93bd4 1861 return true;
8b284dc4
MS		 1862}
1863
26d614df
PE		 1864static int fuse_writepages_fill(struct page *page,
1865 struct writeback_control *wbc, void *_data)
1866{
1867 struct fuse_fill_wb_data *data = _data;
1868 struct fuse_req *req = data->req;
1869 struct inode *inode = data->inode;
f15ecfef 1870 struct fuse_inode *fi = get_fuse_inode(inode);
26d614df
PE		 1871 struct fuse_conn *fc = get_fuse_conn(inode);
1872 struct page *tmp_page;
8b284dc4 1873 bool is_writeback;
26d614df
PE		 1874 int err;
1875
1876 if (!data->ff) {
1877 err = -EIO;
1878 data->ff = fuse_write_file_get(fc, get_fuse_inode(inode));
1879 if (!data->ff)
1880 goto out_unlock;
1881 }
1882
8b284dc4
MS		 1883 /*
1884 * Being under writeback is unlikely but possible. For example direct
1885 * read to an mmaped fuse file will set the page dirty twice; once when
1886 * the pages are faulted with get_user_pages(), and then after the read
1887 * completed.
1888 */
1889 is_writeback = fuse_page_is_writeback(inode, page->index);
1890
1891 if (req && req->num_pages &&
5da784cc 1892 (is_writeback || req->num_pages == fc->max_pages ||
09cbfeaf 1893 (req->num_pages + 1) * PAGE_SIZE > fc->max_write ||
8b284dc4
MS		 1894 data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) {
1895 fuse_writepages_send(data);
1896 data->req = NULL;
e52a8250
MS		 1897 } else if (req && req->num_pages == req->max_pages) {
1898 if (!fuse_req_realloc_pages(fc, req, GFP_NOFS)) {
1899 fuse_writepages_send(data);
1900 req = data->req = NULL;
1901 }
26d614df 1902 }
e52a8250 1903
26d614df
PE		 1904 err = -ENOMEM;
1905 tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
1906 if (!tmp_page)
1907 goto out_unlock;
1908
1909 /*
1910 * The page must not be redirtied until the writeout is completed
1911 * (i.e. userspace has sent a reply to the write request). Otherwise
1912 * there could be more than one temporary page instance for each real
1913 * page.
1914 *
1915 * This is ensured by holding the page lock in page_mkwrite() while
1916 * checking fuse_page_is_writeback(). We already hold the page lock
1917 * since clear_page_dirty_for_io() and keep it held until we add the
1918 * request to the fi->writepages list and increment req->num_pages.
1919 * After this fuse_page_is_writeback() will indicate that the page is
1920 * under writeback, so we can release the page lock.
1921 */
1922 if (data->req == NULL) {
1923 struct fuse_inode *fi = get_fuse_inode(inode);
1924
1925 err = -ENOMEM;
e52a8250 1926 req = fuse_request_alloc_nofs(FUSE_REQ_INLINE_PAGES);
26d614df
PE		 1927 if (!req) {
1928 __free_page(tmp_page);
1929 goto out_unlock;
1930 }
1931
1932 fuse_write_fill(req, data->ff, page_offset(page), 0);
1933 req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
8b284dc4 1934 req->misc.write.next = NULL;
26d614df 1935 req->in.argpages = 1;
825d6d33 1936 __set_bit(FR_BACKGROUND, &req->flags);
26d614df
PE		 1937 req->num_pages = 0;
1938 req->end = fuse_writepage_end;
1939 req->inode = inode;
1940
f15ecfef 1941 spin_lock(&fi->lock);
26d614df 1942 list_add(&req->writepages_entry, &fi->writepages);
f15ecfef 1943 spin_unlock(&fi->lock);
26d614df
PE		 1944
1945 data->req = req;
1946 }
1947 set_page_writeback(page);
1948
1949 copy_highpage(tmp_page, page);
1950 req->pages[req->num_pages] = tmp_page;
1951 req->page_descs[req->num_pages].offset = 0;
1952 req->page_descs[req->num_pages].length = PAGE_SIZE;
1953
93f78d88 1954 inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
11fb9989 1955 inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP);
8b284dc4
MS		 1956
1957 err = 0;
1958 if (is_writeback && fuse_writepage_in_flight(req, page)) {
1959 end_page_writeback(page);
1960 data->req = NULL;
1961 goto out_unlock;
1962 }
2d033eaa 1963 data->orig_pages[req->num_pages] = page;
26d614df
PE		 1964
1965 /*
f15ecfef 1966 * Protected by fi->lock against concurrent access by
26d614df
PE		 1967 * fuse_page_is_writeback().
1968 */
f15ecfef 1969 spin_lock(&fi->lock);
26d614df 1970 req->num_pages++;
f15ecfef 1971 spin_unlock(&fi->lock);
26d614df 1972
26d614df
PE		 1973out_unlock:
1974 unlock_page(page);
1975
1976 return err;
1977}
1978
1979static int fuse_writepages(struct address_space *mapping,
1980 struct writeback_control *wbc)
1981{
1982 struct inode *inode = mapping->host;
5da784cc 1983 struct fuse_conn *fc = get_fuse_conn(inode);
26d614df
PE		 1984 struct fuse_fill_wb_data data;
1985 int err;
1986
1987 err = -EIO;
1988 if (is_bad_inode(inode))
1989 goto out;
1990
1991 data.inode = inode;
1992 data.req = NULL;
1993 data.ff = NULL;
1994
2d033eaa 1995 err = -ENOMEM;
5da784cc 1996 data.orig_pages = kcalloc(fc->max_pages,
f2b3455e 1997 sizeof(struct page *),
2d033eaa
MP		 1998 GFP_NOFS);
1999 if (!data.orig_pages)
2000 goto out;
2001
26d614df
PE		 2002 err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data);
2003 if (data.req) {
2004 /* Ignore errors if we can write at least one page */
2005 BUG_ON(!data.req->num_pages);
2006 fuse_writepages_send(&data);
2007 err = 0;
2008 }
2009 if (data.ff)
2e64ff15 2010 fuse_file_put(data.ff, false, false);
2d033eaa
MP		 2011
2012 kfree(data.orig_pages);
26d614df
PE		 2013out:
2014 return err;
2015}
2016
6b12c1b3
PE		 2017/*
2018 * It's worthy to make sure that space is reserved on disk for the write,
2019 * but how to implement it without killing performance need more thinking.
2020 */
2021static int fuse_write_begin(struct file *file, struct address_space *mapping,
2022 loff_t pos, unsigned len, unsigned flags,
2023 struct page **pagep, void **fsdata)
2024{
09cbfeaf 2025 pgoff_t index = pos >> PAGE_SHIFT;
a455589f 2026 struct fuse_conn *fc = get_fuse_conn(file_inode(file));
6b12c1b3
PE		 2027 struct page *page;
2028 loff_t fsize;
2029 int err = -ENOMEM;
2030
2031 WARN_ON(!fc->writeback_cache);
2032
2033 page = grab_cache_page_write_begin(mapping, index, flags);
2034 if (!page)
2035 goto error;
2036
2037 fuse_wait_on_page_writeback(mapping->host, page->index);
2038
09cbfeaf 2039 if (PageUptodate(page) || len == PAGE_SIZE)
6b12c1b3
PE		 2040 goto success;
2041 /*
2042 * Check if the start this page comes after the end of file, in which
2043 * case the readpage can be optimized away.
2044 */
2045 fsize = i_size_read(mapping->host);
09cbfeaf
KS		 2046 if (fsize <= (pos & PAGE_MASK)) {
2047 size_t off = pos & ~PAGE_MASK;
6b12c1b3
PE		 2048 if (off)
2049 zero_user_segment(page, 0, off);
2050 goto success;
2051 }
2052 err = fuse_do_readpage(file, page);
2053 if (err)
2054 goto cleanup;
2055success:
2056 *pagep = page;
2057 return 0;
2058
2059cleanup:
2060 unlock_page(page);
09cbfeaf 2061 put_page(page);
6b12c1b3
PE		 2062error:
2063 return err;
2064}
2065
2066static int fuse_write_end(struct file *file, struct address_space *mapping,
2067 loff_t pos, unsigned len, unsigned copied,
2068 struct page *page, void *fsdata)
2069{
2070 struct inode *inode = page->mapping->host;
2071
59c3b76c
MS		 2072 /* Haven't copied anything? Skip zeroing, size extending, dirtying. */
2073 if (!copied)
2074 goto unlock;
2075
6b12c1b3
PE		 2076 if (!PageUptodate(page)) {
2077 /* Zero any unwritten bytes at the end of the page */
09cbfeaf 2078 size_t endoff = (pos + copied) & ~PAGE_MASK;
6b12c1b3 2079 if (endoff)
09cbfeaf 2080 zero_user_segment(page, endoff, PAGE_SIZE);
6b12c1b3
PE		 2081 SetPageUptodate(page);
2082 }
2083
2084 fuse_write_update_size(inode, pos + copied);
2085 set_page_dirty(page);
59c3b76c
MS		 2086
2087unlock:
6b12c1b3 2088 unlock_page(page);
09cbfeaf 2089 put_page(page);
6b12c1b3
PE		 2090
2091 return copied;
2092}
2093
3be5a52b
MS		 2094static int fuse_launder_page(struct page *page)
2095{
2096 int err = 0;
2097 if (clear_page_dirty_for_io(page)) {
2098 struct inode *inode = page->mapping->host;
2099 err = fuse_writepage_locked(page);
2100 if (!err)
2101 fuse_wait_on_page_writeback(inode, page->index);
2102 }
2103 return err;
2104}
2105
2106/*
2107 * Write back dirty pages now, because there may not be any suitable
2108 * open files later
2109 */
2110static void fuse_vma_close(struct vm_area_struct *vma)
2111{
2112 filemap_write_and_wait(vma->vm_file->f_mapping);
2113}
2114
2115/*
2116 * Wait for writeback against this page to complete before allowing it
2117 * to be marked dirty again, and hence written back again, possibly
2118 * before the previous writepage completed.
2119 *
2120 * Block here, instead of in ->writepage(), so that the userspace fs
2121 * can only block processes actually operating on the filesystem.
2122 *
2123 * Otherwise unprivileged userspace fs would be able to block
2124 * unrelated:
2125 *
2126 * - page migration
2127 * - sync(2)
2128 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
2129 */
46fb504a 2130static vm_fault_t fuse_page_mkwrite(struct vm_fault *vmf)
3be5a52b 2131{
c2ec175c 2132 struct page *page = vmf->page;
11bac800 2133 struct inode *inode = file_inode(vmf->vma->vm_file);
cca24370 2134
11bac800 2135 file_update_time(vmf->vma->vm_file);
cca24370
MS		 2136 lock_page(page);
2137 if (page->mapping != inode->i_mapping) {
2138 unlock_page(page);
2139 return VM_FAULT_NOPAGE;
2140 }
3be5a52b
MS		 2141
2142 fuse_wait_on_page_writeback(inode, page->index);
cca24370 2143 return VM_FAULT_LOCKED;
3be5a52b
MS		 2144}
2145
f0f37e2f 2146static const struct vm_operations_struct fuse_file_vm_ops = {
3be5a52b
MS		 2147 .close = fuse_vma_close,
2148 .fault = filemap_fault,
f1820361 2149 .map_pages = filemap_map_pages,
3be5a52b
MS		 2150 .page_mkwrite = fuse_page_mkwrite,
2151};
2152
2153static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
2154{
55752a3a
MS		 2155 struct fuse_file *ff = file->private_data;
2156
2157 if (ff->open_flags & FOPEN_DIRECT_IO) {
2158 /* Can't provide the coherency needed for MAP_SHARED */
2159 if (vma->vm_flags & VM_MAYSHARE)
2160 return -ENODEV;
2161
2162 invalidate_inode_pages2(file->f_mapping);
2163
2164 return generic_file_mmap(file, vma);
2165 }
2166
650b22b9
PE		 2167 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
2168 fuse_link_write_file(file);
2169
3be5a52b
MS		 2170 file_accessed(file);
2171 vma->vm_ops = &fuse_file_vm_ops;
b6aeaded
MS		 2172 return 0;
2173}
2174
0b6e9ea0
SF		 2175static int convert_fuse_file_lock(struct fuse_conn *fc,
2176 const struct fuse_file_lock *ffl,
71421259
MS		 2177 struct file_lock *fl)
2178{
2179 switch (ffl->type) {
2180 case F_UNLCK:
2181 break;
2182
2183 case F_RDLCK:
2184 case F_WRLCK:
2185 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
2186 ffl->end < ffl->start)
2187 return -EIO;
2188
2189 fl->fl_start = ffl->start;
2190 fl->fl_end = ffl->end;
0b6e9ea0
SF		 2191
2192 /*
9d5b86ac
BC		 2193 * Convert pid into init's pid namespace. The locks API will
2194 * translate it into the caller's pid namespace.
0b6e9ea0
SF		 2195 */
2196 rcu_read_lock();
9d5b86ac 2197 fl->fl_pid = pid_nr_ns(find_pid_ns(ffl->pid, fc->pid_ns), &init_pid_ns);
0b6e9ea0 2198 rcu_read_unlock();
71421259
MS		 2199 break;
2200
2201 default:
2202 return -EIO;
2203 }
2204 fl->fl_type = ffl->type;
2205 return 0;
2206}
2207
7078187a 2208static void fuse_lk_fill(struct fuse_args *args, struct file *file,
a9ff4f87 2209 const struct file_lock *fl, int opcode, pid_t pid,
7078187a 2210 int flock, struct fuse_lk_in *inarg)
71421259 2211{
6131ffaa 2212 struct inode *inode = file_inode(file);
9c8ef561 2213 struct fuse_conn *fc = get_fuse_conn(inode);
71421259 2214 struct fuse_file *ff = file->private_data;
7078187a
MS		 2215
2216 memset(inarg, 0, sizeof(*inarg));
2217 inarg->fh = ff->fh;
2218 inarg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
2219 inarg->lk.start = fl->fl_start;
2220 inarg->lk.end = fl->fl_end;
2221 inarg->lk.type = fl->fl_type;
2222 inarg->lk.pid = pid;
a9ff4f87 2223 if (flock)
7078187a
MS		 2224 inarg->lk_flags |= FUSE_LK_FLOCK;
2225 args->in.h.opcode = opcode;
2226 args->in.h.nodeid = get_node_id(inode);
2227 args->in.numargs = 1;
2228 args->in.args[0].size = sizeof(*inarg);
2229 args->in.args[0].value = inarg;
71421259
MS		 2230}
2231
2232static int fuse_getlk(struct file *file, struct file_lock *fl)
2233{
6131ffaa 2234 struct inode *inode = file_inode(file);
71421259 2235 struct fuse_conn *fc = get_fuse_conn(inode);
7078187a
MS		 2236 FUSE_ARGS(args);
2237 struct fuse_lk_in inarg;
71421259
MS		 2238 struct fuse_lk_out outarg;
2239 int err;
2240
7078187a
MS		 2241 fuse_lk_fill(&args, file, fl, FUSE_GETLK, 0, 0, &inarg);
2242 args.out.numargs = 1;
2243 args.out.args[0].size = sizeof(outarg);
2244 args.out.args[0].value = &outarg;
2245 err = fuse_simple_request(fc, &args);
71421259 2246 if (!err)
0b6e9ea0 2247 err = convert_fuse_file_lock(fc, &outarg.lk, fl);
71421259
MS		 2248
2249 return err;
2250}
2251
a9ff4f87 2252static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
71421259 2253{
6131ffaa 2254 struct inode *inode = file_inode(file);
71421259 2255 struct fuse_conn *fc = get_fuse_conn(inode);
7078187a
MS		 2256 FUSE_ARGS(args);
2257 struct fuse_lk_in inarg;
71421259 2258 int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
0b6e9ea0
SF		 2259 struct pid *pid = fl->fl_type != F_UNLCK ? task_tgid(current) : NULL;
2260 pid_t pid_nr = pid_nr_ns(pid, fc->pid_ns);
71421259
MS		 2261 int err;
2262
8fb47a4f 2263 if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
48e90761
MS		 2264 /* NLM needs asynchronous locks, which we don't support yet */
2265 return -ENOLCK;
2266 }
2267
71421259 2268 /* Unlock on close is handled by the flush method */
50f2112c 2269 if ((fl->fl_flags & FL_CLOSE_POSIX) == FL_CLOSE_POSIX)
71421259
MS		 2270 return 0;
2271
0b6e9ea0 2272 fuse_lk_fill(&args, file, fl, opcode, pid_nr, flock, &inarg);
7078187a 2273 err = fuse_simple_request(fc, &args);
71421259 2274
a4d27e75
MS		 2275 /* locking is restartable */
2276 if (err == -EINTR)
2277 err = -ERESTARTSYS;
7078187a 2278
71421259
MS		 2279 return err;
2280}
2281
2282static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
2283{
6131ffaa 2284 struct inode *inode = file_inode(file);
71421259
MS		 2285 struct fuse_conn *fc = get_fuse_conn(inode);
2286 int err;
2287
48e90761
MS		 2288 if (cmd == F_CANCELLK) {
2289 err = 0;
2290 } else if (cmd == F_GETLK) {
71421259 2291 if (fc->no_lock) {
9d6a8c5c 2292 posix_test_lock(file, fl);
71421259
MS		 2293 err = 0;
2294 } else
2295 err = fuse_getlk(file, fl);
2296 } else {
2297 if (fc->no_lock)
48e90761 2298 err = posix_lock_file(file, fl, NULL);
71421259 2299 else
a9ff4f87 2300 err = fuse_setlk(file, fl, 0);
71421259
MS		 2301 }
2302 return err;
2303}
2304
a9ff4f87
MS		 2305static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
2306{
6131ffaa 2307 struct inode *inode = file_inode(file);
a9ff4f87
MS		 2308 struct fuse_conn *fc = get_fuse_conn(inode);
2309 int err;
2310
37fb3a30 2311 if (fc->no_flock) {
4f656367 2312 err = locks_lock_file_wait(file, fl);
a9ff4f87 2313 } else {
37fb3a30
MS		 2314 struct fuse_file *ff = file->private_data;
2315
a9ff4f87 2316 /* emulate flock with POSIX locks */
37fb3a30 2317 ff->flock = true;
a9ff4f87
MS		 2318 err = fuse_setlk(file, fl, 1);
2319 }
2320
2321 return err;
2322}
2323
b2d2272f
MS		 2324static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
2325{
2326 struct inode *inode = mapping->host;
2327 struct fuse_conn *fc = get_fuse_conn(inode);
7078187a 2328 FUSE_ARGS(args);
b2d2272f
MS		 2329 struct fuse_bmap_in inarg;
2330 struct fuse_bmap_out outarg;
2331 int err;
2332
2333 if (!inode->i_sb->s_bdev || fc->no_bmap)
2334 return 0;
2335
b2d2272f
MS		 2336 memset(&inarg, 0, sizeof(inarg));
2337 inarg.block = block;
2338 inarg.blocksize = inode->i_sb->s_blocksize;
7078187a
MS		 2339 args.in.h.opcode = FUSE_BMAP;
2340 args.in.h.nodeid = get_node_id(inode);
2341 args.in.numargs = 1;
2342 args.in.args[0].size = sizeof(inarg);
2343 args.in.args[0].value = &inarg;
2344 args.out.numargs = 1;
2345 args.out.args[0].size = sizeof(outarg);
2346 args.out.args[0].value = &outarg;
2347 err = fuse_simple_request(fc, &args);
b2d2272f
MS		 2348 if (err == -ENOSYS)
2349 fc->no_bmap = 1;
2350
2351 return err ? 0 : outarg.block;
2352}
2353
0b5da8db
R		 2354static loff_t fuse_lseek(struct file *file, loff_t offset, int whence)
2355{
2356 struct inode *inode = file->f_mapping->host;
2357 struct fuse_conn *fc = get_fuse_conn(inode);
2358 struct fuse_file *ff = file->private_data;
2359 FUSE_ARGS(args);
2360 struct fuse_lseek_in inarg = {
2361 .fh = ff->fh,
2362 .offset = offset,
2363 .whence = whence
2364 };
2365 struct fuse_lseek_out outarg;
2366 int err;
2367
2368 if (fc->no_lseek)
2369 goto fallback;
2370
2371 args.in.h.opcode = FUSE_LSEEK;
2372 args.in.h.nodeid = ff->nodeid;
2373 args.in.numargs = 1;
2374 args.in.args[0].size = sizeof(inarg);
2375 args.in.args[0].value = &inarg;
2376 args.out.numargs = 1;
2377 args.out.args[0].size = sizeof(outarg);
2378 args.out.args[0].value = &outarg;
2379 err = fuse_simple_request(fc, &args);
2380 if (err) {
2381 if (err == -ENOSYS) {
2382 fc->no_lseek = 1;
2383 goto fallback;
2384 }
2385 return err;
2386 }
2387
2388 return vfs_setpos(file, outarg.offset, inode->i_sb->s_maxbytes);
2389
2390fallback:
5b97eeac 2391 err = fuse_update_attributes(inode, file);
0b5da8db
R		 2392 if (!err)
2393 return generic_file_llseek(file, offset, whence);
2394 else
2395 return err;
2396}
2397
965c8e59 2398static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
5559b8f4
MS		 2399{
2400 loff_t retval;
6131ffaa 2401 struct inode *inode = file_inode(file);
5559b8f4 2402
0b5da8db
R		 2403 switch (whence) {
2404 case SEEK_SET:
2405 case SEEK_CUR:
2406 /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
965c8e59 2407 retval = generic_file_llseek(file, offset, whence);
0b5da8db
R		 2408 break;
2409 case SEEK_END:
5955102c 2410 inode_lock(inode);
5b97eeac 2411 retval = fuse_update_attributes(inode, file);
0b5da8db
R		 2412 if (!retval)
2413 retval = generic_file_llseek(file, offset, whence);
5955102c 2414 inode_unlock(inode);
0b5da8db
R		 2415 break;
2416 case SEEK_HOLE:
2417 case SEEK_DATA:
5955102c 2418 inode_lock(inode);
0b5da8db 2419 retval = fuse_lseek(file, offset, whence);
5955102c 2420 inode_unlock(inode);
0b5da8db
R		 2421 break;
2422 default:
2423 retval = -EINVAL;
2424 }
c07c3d19 2425
5559b8f4
MS		 2426 return retval;
2427}
2428
d9d318d3
MS		 2429/*
2430 * CUSE servers compiled on 32bit broke on 64bit kernels because the
2431 * ABI was defined to be 'struct iovec' which is different on 32bit
2432 * and 64bit. Fortunately we can determine which structure the server
2433 * used from the size of the reply.
2434 */
1baa26b2
MS		 2435static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
2436 size_t transferred, unsigned count,
2437 bool is_compat)
d9d318d3
MS		 2438{
2439#ifdef CONFIG_COMPAT
2440 if (count * sizeof(struct compat_iovec) == transferred) {
2441 struct compat_iovec *ciov = src;
2442 unsigned i;
2443
2444 /*
2445 * With this interface a 32bit server cannot support
2446 * non-compat (i.e. ones coming from 64bit apps) ioctl
2447 * requests
2448 */
2449 if (!is_compat)
2450 return -EINVAL;
2451
2452 for (i = 0; i < count; i++) {
2453 dst[i].iov_base = compat_ptr(ciov[i].iov_base);
2454 dst[i].iov_len = ciov[i].iov_len;
2455 }
2456 return 0;
2457 }
2458#endif
2459
2460 if (count * sizeof(struct iovec) != transferred)
2461 return -EIO;
2462
2463 memcpy(dst, src, transferred);
2464 return 0;
2465}
2466
7572777e 2467/* Make sure iov_length() won't overflow */
5da784cc
CS		 2468static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov,
2469 size_t count)
7572777e
MS		 2470{
2471 size_t n;
5da784cc 2472 u32 max = fc->max_pages << PAGE_SHIFT;
7572777e 2473
fb6ccff6 2474 for (n = 0; n < count; n++, iov++) {
7572777e
MS		 2475 if (iov->iov_len > (size_t) max)
2476 return -ENOMEM;
2477 max -= iov->iov_len;
2478 }
2479 return 0;
2480}
2481
1baa26b2
MS		 2482static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,
2483 void *src, size_t transferred, unsigned count,
2484 bool is_compat)
2485{
2486 unsigned i;
2487 struct fuse_ioctl_iovec *fiov = src;
2488
2489 if (fc->minor < 16) {
2490 return fuse_copy_ioctl_iovec_old(dst, src, transferred,
2491 count, is_compat);
2492 }
2493
2494 if (count * sizeof(struct fuse_ioctl_iovec) != transferred)
2495 return -EIO;
2496
2497 for (i = 0; i < count; i++) {
2498 /* Did the server supply an inappropriate value? */
2499 if (fiov[i].base != (unsigned long) fiov[i].base ||
2500 fiov[i].len != (unsigned long) fiov[i].len)
2501 return -EIO;
2502
2503 dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;
2504 dst[i].iov_len = (size_t) fiov[i].len;
2505
2506#ifdef CONFIG_COMPAT
2507 if (is_compat &&
2508 (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||
2509 (compat_size_t) dst[i].iov_len != fiov[i].len))
2510 return -EIO;
2511#endif
2512 }
2513
2514 return 0;
2515}
2516
2517
59efec7b
TH		 2518/*
2519 * For ioctls, there is no generic way to determine how much memory
2520 * needs to be read and/or written. Furthermore, ioctls are allowed
2521 * to dereference the passed pointer, so the parameter requires deep
2522 * copying but FUSE has no idea whatsoever about what to copy in or
2523 * out.
2524 *
2525 * This is solved by allowing FUSE server to retry ioctl with
2526 * necessary in/out iovecs. Let's assume the ioctl implementation
2527 * needs to read in the following structure.
2528 *
2529 * struct a {
2530 * char *buf;
2531 * size_t buflen;
2532 * }
2533 *
2534 * On the first callout to FUSE server, inarg->in_size and
2535 * inarg->out_size will be NULL; then, the server completes the ioctl
2536 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and
2537 * the actual iov array to
2538 *
2539 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } }
2540 *
2541 * which tells FUSE to copy in the requested area and retry the ioctl.
2542 * On the second round, the server has access to the structure and
2543 * from that it can tell what to look for next, so on the invocation,
2544 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to
2545 *
2546 * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) },
2547 * { .iov_base = a.buf, .iov_len = a.buflen } }
2548 *
2549 * FUSE will copy both struct a and the pointed buffer from the
2550 * process doing the ioctl and retry ioctl with both struct a and the
2551 * buffer.
2552 *
2553 * This time, FUSE server has everything it needs and completes ioctl
2554 * without FUSE_IOCTL_RETRY which finishes the ioctl call.
2555 *
2556 * Copying data out works the same way.
2557 *
2558 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel
2559 * automatically initializes in and out iovs by decoding @cmd with
2560 * _IOC_* macros and the server is not allowed to request RETRY. This
2561 * limits ioctl data transfers to well-formed ioctls and is the forced
2562 * behavior for all FUSE servers.
2563 */
08cbf542
TH		 2564long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
2565 unsigned int flags)
59efec7b 2566{
59efec7b 2567 struct fuse_file *ff = file->private_data;
d36f2487 2568 struct fuse_conn *fc = ff->fc;
59efec7b
TH		 2569 struct fuse_ioctl_in inarg = {
2570 .fh = ff->fh,
2571 .cmd = cmd,
2572 .arg = arg,
2573 .flags = flags
2574 };
2575 struct fuse_ioctl_out outarg;
2576 struct fuse_req *req = NULL;
2577 struct page **pages = NULL;
8ac83505 2578 struct iovec *iov_page = NULL;
59efec7b
TH		 2579 struct iovec *in_iov = NULL, *out_iov = NULL;
2580 unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
acbe5fda
MS		 2581 size_t in_size, out_size, transferred, c;
2582 int err, i;
2583 struct iov_iter ii;
59efec7b 2584
1baa26b2
MS		 2585#if BITS_PER_LONG == 32
2586 inarg.flags |= FUSE_IOCTL_32BIT;
2587#else
6407f44a 2588 if (flags & FUSE_IOCTL_COMPAT) {
1baa26b2 2589 inarg.flags |= FUSE_IOCTL_32BIT;
6407f44a
IA		 2590#ifdef CONFIG_X86_X32
2591 if (in_x32_syscall())
2592 inarg.flags |= FUSE_IOCTL_COMPAT_X32;
2593#endif
2594 }
1baa26b2
MS		 2595#endif
2596
59efec7b 2597 /* assume all the iovs returned by client always fits in a page */
1baa26b2 2598 BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
59efec7b 2599
59efec7b 2600 err = -ENOMEM;
5da784cc 2601 pages = kcalloc(fc->max_pages, sizeof(pages[0]), GFP_KERNEL);
8ac83505 2602 iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
59efec7b
TH		 2603 if (!pages || !iov_page)
2604 goto out;
2605
2606 /*
2607 * If restricted, initialize IO parameters as encoded in @cmd.
2608 * RETRY from server is not allowed.
2609 */
2610 if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
8ac83505 2611 struct iovec *iov = iov_page;
59efec7b 2612
c9f0523d 2613 iov->iov_base = (void __user *)arg;
59efec7b
TH		 2614 iov->iov_len = _IOC_SIZE(cmd);
2615
2616 if (_IOC_DIR(cmd) & _IOC_WRITE) {
2617 in_iov = iov;
2618 in_iovs = 1;
2619 }
2620
2621 if (_IOC_DIR(cmd) & _IOC_READ) {
2622 out_iov = iov;
2623 out_iovs = 1;
2624 }
2625 }
2626
2627 retry:
2628 inarg.in_size = in_size = iov_length(in_iov, in_iovs);
2629 inarg.out_size = out_size = iov_length(out_iov, out_iovs);
2630
2631 /*
2632 * Out data can be used either for actual out data or iovs,
2633 * make sure there always is at least one page.
2634 */
2635 out_size = max_t(size_t, out_size, PAGE_SIZE);
2636 max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);
2637
2638 /* make sure there are enough buffer pages and init request with them */
2639 err = -ENOMEM;
5da784cc 2640 if (max_pages > fc->max_pages)
59efec7b
TH		 2641 goto out;
2642 while (num_pages < max_pages) {
2643 pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
2644 if (!pages[num_pages])
2645 goto out;
2646 num_pages++;
2647 }
2648
54b96670 2649 req = fuse_get_req(fc, num_pages);
59efec7b
TH		 2650 if (IS_ERR(req)) {
2651 err = PTR_ERR(req);
2652 req = NULL;
2653 goto out;
2654 }
2655 memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
2656 req->num_pages = num_pages;
7c190c8b 2657 fuse_page_descs_length_init(req, 0, req->num_pages);
59efec7b
TH		 2658
2659 /* okay, let's send it to the client */
2660 req->in.h.opcode = FUSE_IOCTL;
d36f2487 2661 req->in.h.nodeid = ff->nodeid;
59efec7b
TH		 2662 req->in.numargs = 1;
2663 req->in.args[0].size = sizeof(inarg);
2664 req->in.args[0].value = &inarg;
2665 if (in_size) {
2666 req->in.numargs++;
2667 req->in.args[1].size = in_size;
2668 req->in.argpages = 1;
2669
acbe5fda
MS		 2670 err = -EFAULT;
2671 iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size);
2672 for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= num_pages); i++) {
2673 c = copy_page_from_iter(pages[i], 0, PAGE_SIZE, &ii);
2674 if (c != PAGE_SIZE && iov_iter_count(&ii))
2675 goto out;
2676 }
59efec7b
TH		 2677 }
2678
2679 req->out.numargs = 2;
2680 req->out.args[0].size = sizeof(outarg);
2681 req->out.args[0].value = &outarg;
2682 req->out.args[1].size = out_size;
2683 req->out.argpages = 1;
2684 req->out.argvar = 1;
2685
b93f858a 2686 fuse_request_send(fc, req);
59efec7b
TH		 2687 err = req->out.h.error;
2688 transferred = req->out.args[1].size;
2689 fuse_put_request(fc, req);
2690 req = NULL;
2691 if (err)
2692 goto out;
2693
2694 /* did it ask for retry? */
2695 if (outarg.flags & FUSE_IOCTL_RETRY) {
8ac83505 2696 void *vaddr;
59efec7b
TH		 2697
2698 /* no retry if in restricted mode */
2699 err = -EIO;
2700 if (!(flags & FUSE_IOCTL_UNRESTRICTED))
2701 goto out;
2702
2703 in_iovs = outarg.in_iovs;
2704 out_iovs = outarg.out_iovs;
2705
2706 /*
2707 * Make sure things are in boundary, separate checks
2708 * are to protect against overflow.
2709 */
2710 err = -ENOMEM;
2711 if (in_iovs > FUSE_IOCTL_MAX_IOV ||
2712 out_iovs > FUSE_IOCTL_MAX_IOV ||
2713 in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)
2714 goto out;
2715
2408f6ef 2716 vaddr = kmap_atomic(pages[0]);
1baa26b2 2717 err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
d9d318d3
MS		 2718 transferred, in_iovs + out_iovs,
2719 (flags & FUSE_IOCTL_COMPAT) != 0);
2408f6ef 2720 kunmap_atomic(vaddr);
d9d318d3
MS		 2721 if (err)
2722 goto out;
59efec7b 2723
8ac83505 2724 in_iov = iov_page;
59efec7b
TH		 2725 out_iov = in_iov + in_iovs;
2726
5da784cc 2727 err = fuse_verify_ioctl_iov(fc, in_iov, in_iovs);
7572777e
MS		 2728 if (err)
2729 goto out;
2730
5da784cc 2731 err = fuse_verify_ioctl_iov(fc, out_iov, out_iovs);
7572777e
MS		 2732 if (err)
2733 goto out;
2734
59efec7b
TH		 2735 goto retry;
2736 }
2737
2738 err = -EIO;
2739 if (transferred > inarg.out_size)
2740 goto out;
2741
acbe5fda
MS		 2742 err = -EFAULT;
2743 iov_iter_init(&ii, READ, out_iov, out_iovs, transferred);
2744 for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= num_pages); i++) {
2745 c = copy_page_to_iter(pages[i], 0, PAGE_SIZE, &ii);
2746 if (c != PAGE_SIZE && iov_iter_count(&ii))
2747 goto out;
2748 }
2749 err = 0;
59efec7b
TH		 2750 out:
2751 if (req)
2752 fuse_put_request(fc, req);
8ac83505 2753 free_page((unsigned long) iov_page);
59efec7b
TH		 2754 while (num_pages)
2755 __free_page(pages[--num_pages]);
2756 kfree(pages);
2757
2758 return err ? err : outarg.result;
2759}
08cbf542 2760EXPORT_SYMBOL_GPL(fuse_do_ioctl);
59efec7b 2761
b18da0c5
MS		 2762long fuse_ioctl_common(struct file *file, unsigned int cmd,
2763 unsigned long arg, unsigned int flags)
d36f2487 2764{
6131ffaa 2765 struct inode *inode = file_inode(file);
d36f2487
MS		 2766 struct fuse_conn *fc = get_fuse_conn(inode);
2767
c2132c1b 2768 if (!fuse_allow_current_process(fc))
d36f2487
MS		 2769 return -EACCES;
2770
2771 if (is_bad_inode(inode))
2772 return -EIO;
2773
2774 return fuse_do_ioctl(file, cmd, arg, flags);
2775}
2776
59efec7b
TH		 2777static long fuse_file_ioctl(struct file *file, unsigned int cmd,
2778 unsigned long arg)
2779{
b18da0c5 2780 return fuse_ioctl_common(file, cmd, arg, 0);
59efec7b
TH		 2781}
2782
2783static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
2784 unsigned long arg)
2785{
b18da0c5 2786 return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
59efec7b
TH		 2787}
2788
95668a69
TH		 2789/*
2790 * All files which have been polled are linked to RB tree
2791 * fuse_conn->polled_files which is indexed by kh. Walk the tree and
2792 * find the matching one.
2793 */
2794static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
2795 struct rb_node **parent_out)
2796{
2797 struct rb_node **link = &fc->polled_files.rb_node;
2798 struct rb_node *last = NULL;
2799
2800 while (*link) {
2801 struct fuse_file *ff;
2802
2803 last = *link;
2804 ff = rb_entry(last, struct fuse_file, polled_node);
2805
2806 if (kh < ff->kh)
2807 link = &last->rb_left;
2808 else if (kh > ff->kh)
2809 link = &last->rb_right;
2810 else
2811 return link;
2812 }
2813
2814 if (parent_out)
2815 *parent_out = last;
2816 return link;
2817}
2818
2819/*
2820 * The file is about to be polled. Make sure it's on the polled_files
2821 * RB tree. Note that files once added to the polled_files tree are
2822 * not removed before the file is released. This is because a file
2823 * polled once is likely to be polled again.
2824 */
2825static void fuse_register_polled_file(struct fuse_conn *fc,
2826 struct fuse_file *ff)
2827{
2828 spin_lock(&fc->lock);
2829 if (RB_EMPTY_NODE(&ff->polled_node)) {
f3846266 2830 struct rb_node **link, *uninitialized_var(parent);
95668a69
TH		 2831
2832 link = fuse_find_polled_node(fc, ff->kh, &parent);
2833 BUG_ON(*link);
2834 rb_link_node(&ff->polled_node, parent, link);
2835 rb_insert_color(&ff->polled_node, &fc->polled_files);
2836 }
2837 spin_unlock(&fc->lock);
2838}
2839
076ccb76 2840__poll_t fuse_file_poll(struct file *file, poll_table *wait)
95668a69 2841{
95668a69 2842 struct fuse_file *ff = file->private_data;
797759aa 2843 struct fuse_conn *fc = ff->fc;
95668a69
TH		 2844 struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
2845 struct fuse_poll_out outarg;
7078187a 2846 FUSE_ARGS(args);
95668a69
TH		 2847 int err;
2848
2849 if (fc->no_poll)
2850 return DEFAULT_POLLMASK;
2851
2852 poll_wait(file, &ff->poll_wait, wait);
c71d227f 2853 inarg.events = mangle_poll(poll_requested_events(wait));
95668a69
TH		 2854
2855 /*
2856 * Ask for notification iff there's someone waiting for it.
2857 * The client may ignore the flag and always notify.
2858 */
2859 if (waitqueue_active(&ff->poll_wait)) {
2860 inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
2861 fuse_register_polled_file(fc, ff);
2862 }
2863
7078187a
MS		 2864 args.in.h.opcode = FUSE_POLL;
2865 args.in.h.nodeid = ff->nodeid;
2866 args.in.numargs = 1;
2867 args.in.args[0].size = sizeof(inarg);
2868 args.in.args[0].value = &inarg;
2869 args.out.numargs = 1;
2870 args.out.args[0].size = sizeof(outarg);
2871 args.out.args[0].value = &outarg;
2872 err = fuse_simple_request(fc, &args);
95668a69
TH		 2873
2874 if (!err)
c71d227f 2875 return demangle_poll(outarg.revents);
95668a69
TH		 2876 if (err == -ENOSYS) {
2877 fc->no_poll = 1;
2878 return DEFAULT_POLLMASK;
2879 }
a9a08845 2880 return EPOLLERR;
95668a69 2881}
08cbf542 2882EXPORT_SYMBOL_GPL(fuse_file_poll);
95668a69
TH		 2883
2884/*
2885 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
2886 * wakes up the poll waiters.
2887 */
2888int fuse_notify_poll_wakeup(struct fuse_conn *fc,
2889 struct fuse_notify_poll_wakeup_out *outarg)
2890{
2891 u64 kh = outarg->kh;
2892 struct rb_node **link;
2893
2894 spin_lock(&fc->lock);
2895
2896 link = fuse_find_polled_node(fc, kh, NULL);
2897 if (*link) {
2898 struct fuse_file *ff;
2899
2900 ff = rb_entry(*link, struct fuse_file, polled_node);
2901 wake_up_interruptible_sync(&ff->poll_wait);
2902 }
2903
2904 spin_unlock(&fc->lock);
2905 return 0;
2906}
2907
efb9fa9e
MP		 2908static void fuse_do_truncate(struct file *file)
2909{
2910 struct inode *inode = file->f_mapping->host;
2911 struct iattr attr;
2912
2913 attr.ia_valid = ATTR_SIZE;
2914 attr.ia_size = i_size_read(inode);
2915
2916 attr.ia_file = file;
2917 attr.ia_valid |= ATTR_FILE;
2918
62490330 2919 fuse_do_setattr(file_dentry(file), &attr, file);
efb9fa9e
MP		 2920}
2921
5da784cc 2922static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off)
e5c5f05d 2923{
5da784cc 2924 return round_up(off, fc->max_pages << PAGE_SHIFT);
e5c5f05d
MP		 2925}
2926
4273b793 2927static ssize_t
c8b8e32d 2928fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
4273b793 2929{
9d5722b7 2930 DECLARE_COMPLETION_ONSTACK(wait);
4273b793 2931 ssize_t ret = 0;
60b9df7a
MS		 2932 struct file *file = iocb->ki_filp;
2933 struct fuse_file *ff = file->private_data;
e5c5f05d 2934 bool async_dio = ff->fc->async_dio;
4273b793 2935 loff_t pos = 0;
bcba24cc
MP		 2936 struct inode *inode;
2937 loff_t i_size;
a6cbcd4a 2938 size_t count = iov_iter_count(iter);
c8b8e32d 2939 loff_t offset = iocb->ki_pos;
36cf66ed 2940 struct fuse_io_priv *io;
4273b793 2941
4273b793 2942 pos = offset;
bcba24cc
MP		 2943 inode = file->f_mapping->host;
2944 i_size = i_size_read(inode);
4273b793 2945
6f673763 2946 if ((iov_iter_rw(iter) == READ) && (offset > i_size))
9fe55eea
SW		 2947 return 0;
2948
439ee5f0 2949 /* optimization for short read */
6f673763 2950 if (async_dio && iov_iter_rw(iter) != WRITE && offset + count > i_size) {
439ee5f0
MP		 2951 if (offset >= i_size)
2952 return 0;
5da784cc 2953 iov_iter_truncate(iter, fuse_round_up(ff->fc, i_size - offset));
6b775b18 2954 count = iov_iter_count(iter);
439ee5f0
MP		 2955 }
2956
bcba24cc 2957 io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
36cf66ed
MP		 2958 if (!io)
2959 return -ENOMEM;
bcba24cc 2960 spin_lock_init(&io->lock);
744742d6 2961 kref_init(&io->refcnt);
bcba24cc
MP		 2962 io->reqs = 1;
2963 io->bytes = -1;
2964 io->size = 0;
2965 io->offset = offset;
6f673763 2966 io->write = (iov_iter_rw(iter) == WRITE);
bcba24cc 2967 io->err = 0;
bcba24cc
MP		 2968 /*
2969 * By default, we want to optimize all I/Os with async request
60b9df7a 2970 * submission to the client filesystem if supported.
bcba24cc 2971 */
e5c5f05d 2972 io->async = async_dio;
bcba24cc 2973 io->iocb = iocb;
7879c4e5 2974 io->blocking = is_sync_kiocb(iocb);
bcba24cc
MP		 2975
2976 /*
7879c4e5
AS		 2977 * We cannot asynchronously extend the size of a file.
2978 * In such case the aio will behave exactly like sync io.
bcba24cc 2979 */
7879c4e5
AS		 2980 if ((offset + count > i_size) && iov_iter_rw(iter) == WRITE)
2981 io->blocking = true;
4273b793 2982
7879c4e5 2983 if (io->async && io->blocking) {
744742d6
SF		 2984 /*
2985 * Additional reference to keep io around after
2986 * calling fuse_aio_complete()
2987 */
2988 kref_get(&io->refcnt);
9d5722b7 2989 io->done = &wait;
744742d6 2990 }
9d5722b7 2991
6f673763 2992 if (iov_iter_rw(iter) == WRITE) {
6b775b18 2993 ret = fuse_direct_io(io, iter, &pos, FUSE_DIO_WRITE);
812408fb
AV		 2994 fuse_invalidate_attr(inode);
2995 } else {
d22a943f 2996 ret = __fuse_direct_read(io, iter, &pos);
812408fb 2997 }
36cf66ed 2998
bcba24cc 2999 if (io->async) {
ebacb812
LC		 3000 bool blocking = io->blocking;
3001
bcba24cc
MP		 3002 fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
3003
3004 /* we have a non-extending, async request, so return */
ebacb812 3005 if (!blocking)
bcba24cc
MP		 3006 return -EIOCBQUEUED;
3007
9d5722b7
CH		 3008 wait_for_completion(&wait);
3009 ret = fuse_get_res_by_io(io);
bcba24cc
MP		 3010 }
3011
744742d6 3012 kref_put(&io->refcnt, fuse_io_release);
9d5722b7 3013
6f673763 3014 if (iov_iter_rw(iter) == WRITE) {
efb9fa9e
MP		 3015 if (ret > 0)
3016 fuse_write_update_size(inode, pos);
3017 else if (ret < 0 && offset + count > i_size)
3018 fuse_do_truncate(file);
3019 }
4273b793
AA		 3020
3021 return ret;
3022}
3023
cdadb11c
MS		 3024static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
3025 loff_t length)
05ba1f08
AP		 3026{
3027 struct fuse_file *ff = file->private_data;
1c68271c 3028 struct inode *inode = file_inode(file);
0ab08f57 3029 struct fuse_inode *fi = get_fuse_inode(inode);
05ba1f08 3030 struct fuse_conn *fc = ff->fc;
7078187a 3031 FUSE_ARGS(args);
05ba1f08
AP		 3032 struct fuse_fallocate_in inarg = {
3033 .fh = ff->fh,
3034 .offset = offset,
3035 .length = length,
3036 .mode = mode
3037 };
3038 int err;
14c14414
MP		 3039 bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) ||
3040 (mode & FALLOC_FL_PUNCH_HOLE);
05ba1f08 3041
4adb8302
MS		 3042 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
3043 return -EOPNOTSUPP;
3044
519c6040
MS		 3045 if (fc->no_fallocate)
3046 return -EOPNOTSUPP;
3047
14c14414 3048 if (lock_inode) {
5955102c 3049 inode_lock(inode);
bde52788
MP		 3050 if (mode & FALLOC_FL_PUNCH_HOLE) {
3051 loff_t endbyte = offset + length - 1;
3052 err = filemap_write_and_wait_range(inode->i_mapping,
3053 offset, endbyte);
3054 if (err)
3055 goto out;
3056
3057 fuse_sync_writes(inode);
3058 }
3634a632
BF		 3059 }
3060
0cbade02
LB		 3061 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
3062 offset + length > i_size_read(inode)) {
3063 err = inode_newsize_ok(inode, offset + length);
3064 if (err)
35d6fcbb 3065 goto out;
0cbade02
LB		 3066 }
3067
0ab08f57
MP		 3068 if (!(mode & FALLOC_FL_KEEP_SIZE))
3069 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
3070
7078187a
MS		 3071 args.in.h.opcode = FUSE_FALLOCATE;
3072 args.in.h.nodeid = ff->nodeid;
3073 args.in.numargs = 1;
3074 args.in.args[0].size = sizeof(inarg);
3075 args.in.args[0].value = &inarg;
3076 err = fuse_simple_request(fc, &args);
519c6040
MS		 3077 if (err == -ENOSYS) {
3078 fc->no_fallocate = 1;
3079 err = -EOPNOTSUPP;
3080 }
bee6c307
BF		 3081 if (err)
3082 goto out;
3083
3084 /* we could have extended the file */
b0aa7606
MP		 3085 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
3086 bool changed = fuse_write_update_size(inode, offset + length);
3087
93d2269d
MS		 3088 if (changed && fc->writeback_cache)
3089 file_update_time(file);
b0aa7606 3090 }
bee6c307
BF		 3091
3092 if (mode & FALLOC_FL_PUNCH_HOLE)
3093 truncate_pagecache_range(inode, offset, offset + length - 1);
3094
3095 fuse_invalidate_attr(inode);
3096
3634a632 3097out:
0ab08f57
MP		 3098 if (!(mode & FALLOC_FL_KEEP_SIZE))
3099 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
3100
bde52788 3101 if (lock_inode)
5955102c 3102 inode_unlock(inode);
3634a632 3103
05ba1f08
AP		 3104 return err;
3105}
05ba1f08 3106
88bc7d50
NV		 3107static ssize_t fuse_copy_file_range(struct file *file_in, loff_t pos_in,
3108 struct file *file_out, loff_t pos_out,
3109 size_t len, unsigned int flags)
3110{
3111 struct fuse_file *ff_in = file_in->private_data;
3112 struct fuse_file *ff_out = file_out->private_data;
a2bc9236 3113 struct inode *inode_in = file_inode(file_in);
88bc7d50
NV		 3114 struct inode *inode_out = file_inode(file_out);
3115 struct fuse_inode *fi_out = get_fuse_inode(inode_out);
3116 struct fuse_conn *fc = ff_in->fc;
3117 FUSE_ARGS(args);
3118 struct fuse_copy_file_range_in inarg = {
3119 .fh_in = ff_in->fh,
3120 .off_in = pos_in,
3121 .nodeid_out = ff_out->nodeid,
3122 .fh_out = ff_out->fh,
3123 .off_out = pos_out,
3124 .len = len,
3125 .flags = flags
3126 };
3127 struct fuse_write_out outarg;
3128 ssize_t err;
3129 /* mark unstable when write-back is not used, and file_out gets
3130 * extended */
3131 bool is_unstable = (!fc->writeback_cache) &&
3132 ((pos_out + len) > inode_out->i_size);
3133
3134 if (fc->no_copy_file_range)
3135 return -EOPNOTSUPP;
3136
a2bc9236
MS		 3137 if (fc->writeback_cache) {
3138 inode_lock(inode_in);
3139 err = filemap_write_and_wait_range(inode_in->i_mapping,
3140 pos_in, pos_in + len);
3141 if (!err)
3142 fuse_sync_writes(inode_in);
3143 inode_unlock(inode_in);
3144 if (err)
3145 return err;
3146 }
3147
88bc7d50
NV		 3148 inode_lock(inode_out);
3149
3150 if (fc->writeback_cache) {
3151 err = filemap_write_and_wait_range(inode_out->i_mapping,
3152 pos_out, pos_out + len);
3153 if (err)
3154 goto out;
3155
3156 fuse_sync_writes(inode_out);
3157 }
3158
3159 if (is_unstable)
3160 set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
3161
3162 args.in.h.opcode = FUSE_COPY_FILE_RANGE;
3163 args.in.h.nodeid = ff_in->nodeid;
3164 args.in.numargs = 1;
3165 args.in.args[0].size = sizeof(inarg);
3166 args.in.args[0].value = &inarg;
3167 args.out.numargs = 1;
3168 args.out.args[0].size = sizeof(outarg);
3169 args.out.args[0].value = &outarg;
3170 err = fuse_simple_request(fc, &args);
3171 if (err == -ENOSYS) {
3172 fc->no_copy_file_range = 1;
3173 err = -EOPNOTSUPP;
3174 }
3175 if (err)
3176 goto out;
3177
3178 if (fc->writeback_cache) {
3179 fuse_write_update_size(inode_out, pos_out + outarg.size);
3180 file_update_time(file_out);
3181 }
3182
3183 fuse_invalidate_attr(inode_out);
3184
3185 err = outarg.size;
3186out:
3187 if (is_unstable)
3188 clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
3189
3190 inode_unlock(inode_out);
3191
3192 return err;
3193}
3194
4b6f5d20 3195static const struct file_operations fuse_file_operations = {
5559b8f4 3196 .llseek = fuse_file_llseek,
37c20f16 3197 .read_iter = fuse_file_read_iter,
84c3d55c 3198 .write_iter = fuse_file_write_iter,
b6aeaded
MS		 3199 .mmap = fuse_file_mmap,
3200 .open = fuse_open,
3201 .flush = fuse_flush,
3202 .release = fuse_release,
3203 .fsync = fuse_fsync,
71421259 3204 .lock = fuse_file_lock,
a9ff4f87 3205 .flock = fuse_file_flock,
3c3db095
MS		 3206 .splice_read = generic_file_splice_read,
3207 .splice_write = iter_file_splice_write,
59efec7b
TH		 3208 .unlocked_ioctl = fuse_file_ioctl,
3209 .compat_ioctl = fuse_file_compat_ioctl,
95668a69 3210 .poll = fuse_file_poll,
05ba1f08 3211 .fallocate = fuse_file_fallocate,
d4136d60 3212 .copy_file_range = fuse_copy_file_range,
413ef8cb
MS		 3213};
3214
f5e54d6e 3215static const struct address_space_operations fuse_file_aops = {
b6aeaded 3216 .readpage = fuse_readpage,
3be5a52b 3217 .writepage = fuse_writepage,
26d614df 3218 .writepages = fuse_writepages,
3be5a52b 3219 .launder_page = fuse_launder_page,
db50b96c 3220 .readpages = fuse_readpages,
3be5a52b 3221 .set_page_dirty = __set_page_dirty_nobuffers,
b2d2272f 3222 .bmap = fuse_bmap,
4273b793 3223 .direct_IO = fuse_direct_IO,
6b12c1b3
PE		 3224 .write_begin = fuse_write_begin,
3225 .write_end = fuse_write_end,
b6aeaded
MS		 3226};
3227
3228void fuse_init_file_inode(struct inode *inode)
3229{
ab2257e9
MS		 3230 struct fuse_inode *fi = get_fuse_inode(inode);
3231
45323fb7
MS		 3232 inode->i_fop = &fuse_file_operations;
3233 inode->i_data.a_ops = &fuse_file_aops;
ab2257e9
MS		 3234
3235 INIT_LIST_HEAD(&fi->write_files);
3236 INIT_LIST_HEAD(&fi->queued_writes);
3237 fi->writectr = 0;
3238 init_waitqueue_head(&fi->page_waitq);
3239 INIT_LIST_HEAD(&fi->writepages);
b6aeaded 3240}
Linux 6.x block layer and io_uring tree(s)