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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* AFS filesystem file handling
3 *
4 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells ([email protected])
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/fs.h>
12#include <linux/pagemap.h>
13#include <linux/writeback.h>
14#include <linux/gfp.h>
15#include <linux/task_io_accounting_ops.h>
16#include <linux/mm.h>
17#include <linux/swap.h>
18#include <linux/netfs.h>
19#include <trace/events/netfs.h>
20#include "internal.h"
21
22static int afs_file_mmap_prepare(struct vm_area_desc *desc);
23
24static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
25static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
26 struct pipe_inode_info *pipe,
27 size_t len, unsigned int flags);
28static void afs_vm_open(struct vm_area_struct *area);
29static void afs_vm_close(struct vm_area_struct *area);
30static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff);
31static int afs_mapped(unsigned long start, unsigned long end, pgoff_t pgoff,
32 const struct file *file, void **vm_private_data);
33
34const struct file_operations afs_file_operations = {
35 .open = afs_open,
36 .release = afs_release,
37 .llseek = generic_file_llseek,
38 .read_iter = afs_file_read_iter,
39 .write_iter = netfs_file_write_iter,
40 .mmap_prepare = afs_file_mmap_prepare,
41 .splice_read = afs_file_splice_read,
42 .splice_write = iter_file_splice_write,
43 .fsync = afs_fsync,
44 .lock = afs_lock,
45 .flock = afs_flock,
46};
47
48const struct inode_operations afs_file_inode_operations = {
49 .getattr = afs_getattr,
50 .setattr = afs_setattr,
51 .permission = afs_permission,
52};
53
54const struct address_space_operations afs_file_aops = {
55 .direct_IO = noop_direct_IO,
56 .read_folio = netfs_read_folio,
57 .readahead = netfs_readahead,
58 .dirty_folio = netfs_dirty_folio,
59 .release_folio = netfs_release_folio,
60 .invalidate_folio = netfs_invalidate_folio,
61 .migrate_folio = filemap_migrate_folio,
62 .writepages = afs_writepages,
63};
64
65static const struct vm_operations_struct afs_vm_ops = {
66 .mapped = afs_mapped,
67 .open = afs_vm_open,
68 .close = afs_vm_close,
69 .fault = filemap_fault,
70 .map_pages = afs_vm_map_pages,
71 .page_mkwrite = afs_page_mkwrite,
72};
73
74/*
75 * Discard a pin on a writeback key.
76 */
77void afs_put_wb_key(struct afs_wb_key *wbk)
78{
79 if (wbk && refcount_dec_and_test(&wbk->usage)) {
80 key_put(wbk->key);
81 kfree(wbk);
82 }
83}
84
85/*
86 * Cache key for writeback.
87 */
88int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af)
89{
90 struct afs_wb_key *wbk, *p;
91
92 wbk = kzalloc_obj(struct afs_wb_key);
93 if (!wbk)
94 return -ENOMEM;
95 refcount_set(&wbk->usage, 2);
96 wbk->key = af->key;
97
98 spin_lock(&vnode->wb_lock);
99 list_for_each_entry(p, &vnode->wb_keys, vnode_link) {
100 if (p->key == wbk->key)
101 goto found;
102 }
103
104 key_get(wbk->key);
105 list_add_tail(&wbk->vnode_link, &vnode->wb_keys);
106 spin_unlock(&vnode->wb_lock);
107 af->wb = wbk;
108 return 0;
109
110found:
111 refcount_inc(&p->usage);
112 spin_unlock(&vnode->wb_lock);
113 af->wb = p;
114 kfree(wbk);
115 return 0;
116}
117
118/*
119 * open an AFS file or directory and attach a key to it
120 */
121int afs_open(struct inode *inode, struct file *file)
122{
123 struct afs_vnode *vnode = AFS_FS_I(inode);
124 struct afs_file *af;
125 struct key *key;
126 int ret;
127
128 _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
129
130 key = afs_request_key(vnode->volume->cell);
131 if (IS_ERR(key)) {
132 ret = PTR_ERR(key);
133 goto error;
134 }
135
136 af = kzalloc_obj(*af);
137 if (!af) {
138 ret = -ENOMEM;
139 goto error_key;
140 }
141 af->key = key;
142
143 ret = afs_validate(vnode, key);
144 if (ret < 0)
145 goto error_af;
146
147 if (file->f_mode & FMODE_WRITE) {
148 ret = afs_cache_wb_key(vnode, af);
149 if (ret < 0)
150 goto error_af;
151 }
152
153 if (file->f_flags & O_TRUNC)
154 set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
155
156 fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE);
157
158 file->private_data = af;
159 _leave(" = 0");
160 return 0;
161
162error_af:
163 kfree(af);
164error_key:
165 key_put(key);
166error:
167 _leave(" = %d", ret);
168 return ret;
169}
170
171/*
172 * release an AFS file or directory and discard its key
173 */
174int afs_release(struct inode *inode, struct file *file)
175{
176 struct afs_vnode_cache_aux aux;
177 struct afs_vnode *vnode = AFS_FS_I(inode);
178 struct afs_file *af = file->private_data;
179 loff_t i_size;
180 int ret = 0;
181
182 _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
183
184 if ((file->f_mode & FMODE_WRITE))
185 ret = vfs_fsync(file, 0);
186
187 file->private_data = NULL;
188 if (af->wb)
189 afs_put_wb_key(af->wb);
190
191 if ((file->f_mode & FMODE_WRITE)) {
192 i_size = i_size_read(&vnode->netfs.inode);
193 afs_set_cache_aux(vnode, &aux);
194 fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size);
195 } else {
196 fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
197 }
198
199 key_put(af->key);
200 kfree(af);
201 afs_prune_wb_keys(vnode);
202 _leave(" = %d", ret);
203 return ret;
204}
205
206static void afs_fetch_data_notify(struct afs_operation *op)
207{
208 struct netfs_io_subrequest *subreq = op->fetch.subreq;
209
210 subreq->error = afs_op_error(op);
211 netfs_read_subreq_terminated(subreq);
212}
213
214static void afs_fetch_data_success(struct afs_operation *op)
215{
216 struct afs_vnode *vnode = op->file[0].vnode;
217
218 _enter("op=%08x", op->debug_id);
219 afs_vnode_commit_status(op, &op->file[0]);
220 afs_stat_v(vnode, n_fetches);
221 atomic_long_add(op->fetch.subreq->transferred, &op->net->n_fetch_bytes);
222 afs_fetch_data_notify(op);
223}
224
225static void afs_fetch_data_aborted(struct afs_operation *op)
226{
227 afs_check_for_remote_deletion(op);
228 afs_fetch_data_notify(op);
229}
230
231const struct afs_operation_ops afs_fetch_data_operation = {
232 .issue_afs_rpc = afs_fs_fetch_data,
233 .issue_yfs_rpc = yfs_fs_fetch_data,
234 .success = afs_fetch_data_success,
235 .aborted = afs_fetch_data_aborted,
236 .failed = afs_fetch_data_notify,
237};
238
239static void afs_issue_read_call(struct afs_operation *op)
240{
241 op->call_responded = false;
242 op->call_error = 0;
243 op->call_abort_code = 0;
244 if (test_bit(AFS_SERVER_FL_IS_YFS, &op->server->flags))
245 yfs_fs_fetch_data(op);
246 else
247 afs_fs_fetch_data(op);
248}
249
250static void afs_end_read(struct afs_operation *op)
251{
252 if (op->call_responded && op->server)
253 set_bit(AFS_SERVER_FL_RESPONDING, &op->server->flags);
254
255 if (!afs_op_error(op))
256 afs_fetch_data_success(op);
257 else if (op->cumul_error.aborted)
258 afs_fetch_data_aborted(op);
259 else
260 afs_fetch_data_notify(op);
261
262 afs_end_vnode_operation(op);
263 afs_put_operation(op);
264}
265
266/*
267 * Perform I/O processing on an asynchronous call. The work item carries a ref
268 * to the call struct that we either need to release or to pass on.
269 */
270static void afs_read_receive(struct afs_call *call)
271{
272 struct afs_operation *op = call->op;
273 enum afs_call_state state;
274
275 _enter("");
276
277 state = READ_ONCE(call->state);
278 if (state == AFS_CALL_COMPLETE)
279 return;
280 trace_afs_read_recv(op, call);
281
282 while (state < AFS_CALL_COMPLETE && READ_ONCE(call->need_attention)) {
283 WRITE_ONCE(call->need_attention, false);
284 afs_deliver_to_call(call);
285 state = READ_ONCE(call->state);
286 }
287
288 if (state < AFS_CALL_COMPLETE) {
289 netfs_read_subreq_progress(op->fetch.subreq);
290 if (rxrpc_kernel_check_life(call->net->socket, call->rxcall))
291 return;
292 /* rxrpc terminated the call. */
293 afs_set_call_complete(call, call->error, call->abort_code);
294 }
295
296 op->call_abort_code = call->abort_code;
297 op->call_error = call->error;
298 op->call_responded = call->responded;
299 op->call = NULL;
300 call->op = NULL;
301 afs_put_call(call);
302
303 /* If the call failed, then we need to crank the server rotation
304 * handle and try the next.
305 */
306 if (afs_select_fileserver(op)) {
307 afs_issue_read_call(op);
308 return;
309 }
310
311 afs_end_read(op);
312}
313
314void afs_fetch_data_async_rx(struct work_struct *work)
315{
316 struct afs_call *call = container_of(work, struct afs_call, async_work);
317
318 afs_read_receive(call);
319 afs_put_call(call);
320}
321
322void afs_fetch_data_immediate_cancel(struct afs_call *call)
323{
324 if (call->async) {
325 afs_get_call(call, afs_call_trace_wake);
326 if (!queue_work(afs_async_calls, &call->async_work))
327 afs_deferred_put_call(call);
328 flush_work(&call->async_work);
329 }
330}
331
332/*
333 * Fetch file data from the volume.
334 */
335static void afs_issue_read(struct netfs_io_subrequest *subreq)
336{
337 struct afs_operation *op;
338 struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
339 struct key *key = subreq->rreq->netfs_priv;
340
341 _enter("%s{%llx:%llu.%u},%x,,,",
342 vnode->volume->name,
343 vnode->fid.vid,
344 vnode->fid.vnode,
345 vnode->fid.unique,
346 key_serial(key));
347
348 op = afs_alloc_operation(key, vnode->volume);
349 if (IS_ERR(op)) {
350 subreq->error = PTR_ERR(op);
351 netfs_read_subreq_terminated(subreq);
352 return;
353 }
354
355 afs_op_set_vnode(op, 0, vnode);
356
357 op->fetch.subreq = subreq;
358 op->ops = &afs_fetch_data_operation;
359
360 trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
361
362 if (subreq->rreq->origin == NETFS_READAHEAD ||
363 subreq->rreq->iocb) {
364 op->flags |= AFS_OPERATION_ASYNC;
365
366 if (!afs_begin_vnode_operation(op)) {
367 subreq->error = afs_put_operation(op);
368 netfs_read_subreq_terminated(subreq);
369 return;
370 }
371
372 if (!afs_select_fileserver(op)) {
373 afs_end_read(op);
374 return;
375 }
376
377 afs_issue_read_call(op);
378 } else {
379 afs_do_sync_operation(op);
380 }
381}
382
383static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
384{
385 struct afs_vnode *vnode = AFS_FS_I(rreq->inode);
386
387 if (file)
388 rreq->netfs_priv = key_get(afs_file_key(file));
389 rreq->rsize = 256 * 1024;
390 rreq->wsize = 256 * 1024 * 1024;
391
392 switch (rreq->origin) {
393 case NETFS_READ_SINGLE:
394 if (!file) {
395 struct key *key = afs_request_key(vnode->volume->cell);
396
397 if (IS_ERR(key))
398 return PTR_ERR(key);
399 rreq->netfs_priv = key;
400 }
401 break;
402 case NETFS_WRITEBACK:
403 case NETFS_UNBUFFERED_WRITE:
404 case NETFS_DIO_WRITE:
405 if (S_ISREG(rreq->inode->i_mode))
406 rreq->io_streams[0].avail = true;
407 break;
408 case NETFS_WRITEBACK_SINGLE:
409 default:
410 break;
411 }
412 return 0;
413}
414
415static int afs_check_write_begin(struct file *file, uoff_t pos, unsigned len,
416 struct folio **foliop, void **_fsdata)
417{
418 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
419
420 return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0;
421}
422
423static void afs_free_request(struct netfs_io_request *rreq)
424{
425 key_put(rreq->netfs_priv);
426 afs_put_wb_key(rreq->netfs_priv2);
427}
428
429/*
430 * Set the file size and block count, taking ->cb_lock and ->i_lock to maintain
431 * coherency and prevent 64-bit tearing on 32-bit arches.
432 *
433 * Also, estimate the number of 512 bytes blocks used, rounded up to nearest 1K
434 * for consistency with other AFS clients.
435 */
436void afs_set_i_size(struct afs_vnode *vnode, uoff_t new_i_size)
437{
438 struct inode *inode = &vnode->netfs.inode;
439 loff_t i_size;
440
441 write_seqlock(&vnode->cb_lock);
442 spin_lock(&inode->i_lock);
443 i_size = i_size_read(inode);
444 if (new_i_size > i_size) {
445 i_size_write(inode, new_i_size);
446 inode_set_bytes(inode, round_up(new_i_size, 1024));
447 }
448 spin_unlock(&inode->i_lock);
449 write_sequnlock(&vnode->cb_lock);
450}
451
452static void afs_update_i_size(struct inode *inode, uoff_t new_i_size)
453{
454 afs_set_i_size(AFS_FS_I(inode), new_i_size);
455}
456
457static void afs_netfs_invalidate_cache(struct netfs_io_request *wreq)
458{
459 struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
460
461 afs_invalidate_cache(vnode, 0);
462}
463
464const struct netfs_request_ops afs_req_ops = {
465 .init_request = afs_init_request,
466 .free_request = afs_free_request,
467 .check_write_begin = afs_check_write_begin,
468 .issue_read = afs_issue_read,
469 .update_i_size = afs_update_i_size,
470 .invalidate_cache = afs_netfs_invalidate_cache,
471 .begin_writeback = afs_begin_writeback,
472 .prepare_write = afs_prepare_write,
473 .issue_write = afs_issue_write,
474 .retry_request = afs_retry_request,
475};
476
477static void afs_add_open_mmap(struct afs_vnode *vnode)
478{
479 if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) {
480 down_write(&vnode->volume->open_mmaps_lock);
481
482 if (list_empty(&vnode->cb_mmap_link))
483 list_add_tail(&vnode->cb_mmap_link, &vnode->volume->open_mmaps);
484
485 up_write(&vnode->volume->open_mmaps_lock);
486 }
487}
488
489static void afs_drop_open_mmap(struct afs_vnode *vnode)
490{
491 if (atomic_add_unless(&vnode->cb_nr_mmap, -1, 1))
492 return;
493
494 down_write(&vnode->volume->open_mmaps_lock);
495
496 read_seqlock_excl(&vnode->cb_lock);
497 // the only place where ->cb_nr_mmap may hit 0
498 // see __afs_break_callback() for the other side...
499 if (atomic_dec_and_test(&vnode->cb_nr_mmap))
500 list_del_init(&vnode->cb_mmap_link);
501 read_sequnlock_excl(&vnode->cb_lock);
502
503 up_write(&vnode->volume->open_mmaps_lock);
504 flush_work(&vnode->cb_work);
505}
506
507/*
508 * Handle setting up a memory mapping on an AFS file.
509 */
510static int afs_file_mmap_prepare(struct vm_area_desc *desc)
511{
512 int ret;
513
514 ret = generic_file_mmap_prepare(desc);
515 if (ret)
516 return ret;
517
518 desc->vm_ops = &afs_vm_ops;
519 return ret;
520}
521
522static int afs_mapped(unsigned long start, unsigned long end, pgoff_t pgoff,
523 const struct file *file, void **vm_private_data)
524{
525 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
526
527 afs_add_open_mmap(vnode);
528 return 0;
529}
530
531static void afs_vm_open(struct vm_area_struct *vma)
532{
533 struct file *file = vma->vm_file;
534 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
535
536 afs_add_open_mmap(vnode);
537}
538
539static void afs_vm_close(struct vm_area_struct *vma)
540{
541 struct file *file = vma->vm_file;
542 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
543
544 afs_drop_open_mmap(vnode);
545}
546
547static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff)
548{
549 struct file *file = vmf->vma->vm_file;
550 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
551
552 if (afs_check_validity(vnode))
553 return filemap_map_pages(vmf, start_pgoff, end_pgoff);
554 return 0;
555}
556
557static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
558{
559 struct inode *inode = file_inode(iocb->ki_filp);
560 struct afs_vnode *vnode = AFS_FS_I(inode);
561 struct afs_file *af = iocb->ki_filp->private_data;
562 ssize_t ret;
563
564 if (iocb->ki_flags & IOCB_DIRECT)
565 return netfs_unbuffered_read_iter(iocb, iter);
566
567 ret = netfs_start_io_read(inode);
568 if (ret < 0)
569 return ret;
570 ret = afs_validate(vnode, af->key);
571 if (ret == 0)
572 ret = filemap_read(iocb, iter, 0);
573 netfs_end_io_read(inode);
574 return ret;
575}
576
577static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
578 struct pipe_inode_info *pipe,
579 size_t len, unsigned int flags)
580{
581 struct inode *inode = file_inode(in);
582 struct afs_vnode *vnode = AFS_FS_I(inode);
583 struct afs_file *af = in->private_data;
584 ssize_t ret;
585
586 ret = netfs_start_io_read(inode);
587 if (ret < 0)
588 return ret;
589 ret = afs_validate(vnode, af->key);
590 if (ret == 0)
591 ret = filemap_splice_read(in, ppos, pipe, len, flags);
592 netfs_end_io_read(inode);
593 return ret;
594}