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1/* AFS filesystem file handling
2 *
3 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/fs.h>
16#include <linux/pagemap.h>
17#include <linux/writeback.h>
18#include <linux/gfp.h>
19#include "internal.h"
20
21static int afs_readpage(struct file *file, struct page *page);
22static void afs_invalidatepage(struct page *page, unsigned int offset,
23 unsigned int length);
24static int afs_releasepage(struct page *page, gfp_t gfp_flags);
25static int afs_launder_page(struct page *page);
26
27static int afs_readpages(struct file *filp, struct address_space *mapping,
28 struct list_head *pages, unsigned nr_pages);
29
30const struct file_operations afs_file_operations = {
31 .open = afs_open,
32 .release = afs_release,
33 .llseek = generic_file_llseek,
34 .read = do_sync_read,
35 .write = do_sync_write,
36 .aio_read = generic_file_aio_read,
37 .aio_write = afs_file_write,
38 .mmap = generic_file_readonly_mmap,
39 .splice_read = generic_file_splice_read,
40 .fsync = afs_fsync,
41 .lock = afs_lock,
42 .flock = afs_flock,
43};
44
45const struct inode_operations afs_file_inode_operations = {
46 .getattr = afs_getattr,
47 .setattr = afs_setattr,
48 .permission = afs_permission,
49};
50
51const struct address_space_operations afs_fs_aops = {
52 .readpage = afs_readpage,
53 .readpages = afs_readpages,
54 .set_page_dirty = afs_set_page_dirty,
55 .launder_page = afs_launder_page,
56 .releasepage = afs_releasepage,
57 .invalidatepage = afs_invalidatepage,
58 .write_begin = afs_write_begin,
59 .write_end = afs_write_end,
60 .writepage = afs_writepage,
61 .writepages = afs_writepages,
62};
63
64/*
65 * open an AFS file or directory and attach a key to it
66 */
67int afs_open(struct inode *inode, struct file *file)
68{
69 struct afs_vnode *vnode = AFS_FS_I(inode);
70 struct key *key;
71 int ret;
72
73 _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
74
75 key = afs_request_key(vnode->volume->cell);
76 if (IS_ERR(key)) {
77 _leave(" = %ld [key]", PTR_ERR(key));
78 return PTR_ERR(key);
79 }
80
81 ret = afs_validate(vnode, key);
82 if (ret < 0) {
83 _leave(" = %d [val]", ret);
84 return ret;
85 }
86
87 file->private_data = key;
88 _leave(" = 0");
89 return 0;
90}
91
92/*
93 * release an AFS file or directory and discard its key
94 */
95int afs_release(struct inode *inode, struct file *file)
96{
97 struct afs_vnode *vnode = AFS_FS_I(inode);
98
99 _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode);
100
101 key_put(file->private_data);
102 _leave(" = 0");
103 return 0;
104}
105
106#ifdef CONFIG_AFS_FSCACHE
107/*
108 * deal with notification that a page was read from the cache
109 */
110static void afs_file_readpage_read_complete(struct page *page,
111 void *data,
112 int error)
113{
114 _enter("%p,%p,%d", page, data, error);
115
116 /* if the read completes with an error, we just unlock the page and let
117 * the VM reissue the readpage */
118 if (!error)
119 SetPageUptodate(page);
120 unlock_page(page);
121}
122#endif
123
124/*
125 * read page from file, directory or symlink, given a key to use
126 */
127int afs_page_filler(void *data, struct page *page)
128{
129 struct inode *inode = page->mapping->host;
130 struct afs_vnode *vnode = AFS_FS_I(inode);
131 struct key *key = data;
132 size_t len;
133 off_t offset;
134 int ret;
135
136 _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
137
138 BUG_ON(!PageLocked(page));
139
140 ret = -ESTALE;
141 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
142 goto error;
143
144 /* is it cached? */
145#ifdef CONFIG_AFS_FSCACHE
146 ret = fscache_read_or_alloc_page(vnode->cache,
147 page,
148 afs_file_readpage_read_complete,
149 NULL,
150 GFP_KERNEL);
151#else
152 ret = -ENOBUFS;
153#endif
154 switch (ret) {
155 /* read BIO submitted (page in cache) */
156 case 0:
157 break;
158
159 /* page not yet cached */
160 case -ENODATA:
161 _debug("cache said ENODATA");
162 goto go_on;
163
164 /* page will not be cached */
165 case -ENOBUFS:
166 _debug("cache said ENOBUFS");
167 default:
168 go_on:
169 offset = page->index << PAGE_CACHE_SHIFT;
170 len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);
171
172 /* read the contents of the file from the server into the
173 * page */
174 ret = afs_vnode_fetch_data(vnode, key, offset, len, page);
175 if (ret < 0) {
176 if (ret == -ENOENT) {
177 _debug("got NOENT from server"
178 " - marking file deleted and stale");
179 set_bit(AFS_VNODE_DELETED, &vnode->flags);
180 ret = -ESTALE;
181 }
182
183#ifdef CONFIG_AFS_FSCACHE
184 fscache_uncache_page(vnode->cache, page);
185#endif
186 BUG_ON(PageFsCache(page));
187 goto error;
188 }
189
190 SetPageUptodate(page);
191
192 /* send the page to the cache */
193#ifdef CONFIG_AFS_FSCACHE
194 if (PageFsCache(page) &&
195 fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) {
196 fscache_uncache_page(vnode->cache, page);
197 BUG_ON(PageFsCache(page));
198 }
199#endif
200 unlock_page(page);
201 }
202
203 _leave(" = 0");
204 return 0;
205
206error:
207 SetPageError(page);
208 unlock_page(page);
209 _leave(" = %d", ret);
210 return ret;
211}
212
213/*
214 * read page from file, directory or symlink, given a file to nominate the key
215 * to be used
216 */
217static int afs_readpage(struct file *file, struct page *page)
218{
219 struct key *key;
220 int ret;
221
222 if (file) {
223 key = file->private_data;
224 ASSERT(key != NULL);
225 ret = afs_page_filler(key, page);
226 } else {
227 struct inode *inode = page->mapping->host;
228 key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell);
229 if (IS_ERR(key)) {
230 ret = PTR_ERR(key);
231 } else {
232 ret = afs_page_filler(key, page);
233 key_put(key);
234 }
235 }
236 return ret;
237}
238
239/*
240 * read a set of pages
241 */
242static int afs_readpages(struct file *file, struct address_space *mapping,
243 struct list_head *pages, unsigned nr_pages)
244{
245 struct key *key = file->private_data;
246 struct afs_vnode *vnode;
247 int ret = 0;
248
249 _enter("{%d},{%lu},,%d",
250 key_serial(key), mapping->host->i_ino, nr_pages);
251
252 ASSERT(key != NULL);
253
254 vnode = AFS_FS_I(mapping->host);
255 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
256 _leave(" = -ESTALE");
257 return -ESTALE;
258 }
259
260 /* attempt to read as many of the pages as possible */
261#ifdef CONFIG_AFS_FSCACHE
262 ret = fscache_read_or_alloc_pages(vnode->cache,
263 mapping,
264 pages,
265 &nr_pages,
266 afs_file_readpage_read_complete,
267 NULL,
268 mapping_gfp_mask(mapping));
269#else
270 ret = -ENOBUFS;
271#endif
272
273 switch (ret) {
274 /* all pages are being read from the cache */
275 case 0:
276 BUG_ON(!list_empty(pages));
277 BUG_ON(nr_pages != 0);
278 _leave(" = 0 [reading all]");
279 return 0;
280
281 /* there were pages that couldn't be read from the cache */
282 case -ENODATA:
283 case -ENOBUFS:
284 break;
285
286 /* other error */
287 default:
288 _leave(" = %d", ret);
289 return ret;
290 }
291
292 /* load the missing pages from the network */
293 ret = read_cache_pages(mapping, pages, afs_page_filler, key);
294
295 _leave(" = %d [netting]", ret);
296 return ret;
297}
298
299/*
300 * write back a dirty page
301 */
302static int afs_launder_page(struct page *page)
303{
304 _enter("{%lu}", page->index);
305
306 return 0;
307}
308
309/*
310 * invalidate part or all of a page
311 * - release a page and clean up its private data if offset is 0 (indicating
312 * the entire page)
313 */
314static void afs_invalidatepage(struct page *page, unsigned int offset,
315 unsigned int length)
316{
317 struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
318
319 _enter("{%lu},%u,%u", page->index, offset, length);
320
321 BUG_ON(!PageLocked(page));
322
323 /* we clean up only if the entire page is being invalidated */
324 if (offset == 0 && length == PAGE_CACHE_SIZE) {
325#ifdef CONFIG_AFS_FSCACHE
326 if (PageFsCache(page)) {
327 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
328 fscache_wait_on_page_write(vnode->cache, page);
329 fscache_uncache_page(vnode->cache, page);
330 }
331#endif
332
333 if (PagePrivate(page)) {
334 if (wb && !PageWriteback(page)) {
335 set_page_private(page, 0);
336 afs_put_writeback(wb);
337 }
338
339 if (!page_private(page))
340 ClearPagePrivate(page);
341 }
342 }
343
344 _leave("");
345}
346
347/*
348 * release a page and clean up its private state if it's not busy
349 * - return true if the page can now be released, false if not
350 */
351static int afs_releasepage(struct page *page, gfp_t gfp_flags)
352{
353 struct afs_writeback *wb = (struct afs_writeback *) page_private(page);
354 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
355
356 _enter("{{%x:%u}[%lu],%lx},%x",
357 vnode->fid.vid, vnode->fid.vnode, page->index, page->flags,
358 gfp_flags);
359
360 /* deny if page is being written to the cache and the caller hasn't
361 * elected to wait */
362#ifdef CONFIG_AFS_FSCACHE
363 if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
364 _leave(" = F [cache busy]");
365 return 0;
366 }
367#endif
368
369 if (PagePrivate(page)) {
370 if (wb) {
371 set_page_private(page, 0);
372 afs_put_writeback(wb);
373 }
374 ClearPagePrivate(page);
375 }
376
377 /* indicate that the page can be released */
378 _leave(" = T");
379 return 1;
380}
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 (dhowells@redhat.com)
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 "internal.h"
20
21static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
22static int afs_symlink_read_folio(struct file *file, struct folio *folio);
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);
31
32const struct file_operations afs_file_operations = {
33 .open = afs_open,
34 .release = afs_release,
35 .llseek = generic_file_llseek,
36 .read_iter = afs_file_read_iter,
37 .write_iter = netfs_file_write_iter,
38 .mmap = afs_file_mmap,
39 .splice_read = afs_file_splice_read,
40 .splice_write = iter_file_splice_write,
41 .fsync = afs_fsync,
42 .lock = afs_lock,
43 .flock = afs_flock,
44};
45
46const struct inode_operations afs_file_inode_operations = {
47 .getattr = afs_getattr,
48 .setattr = afs_setattr,
49 .permission = afs_permission,
50};
51
52const struct address_space_operations afs_file_aops = {
53 .direct_IO = noop_direct_IO,
54 .read_folio = netfs_read_folio,
55 .readahead = netfs_readahead,
56 .dirty_folio = netfs_dirty_folio,
57 .launder_folio = netfs_launder_folio,
58 .release_folio = netfs_release_folio,
59 .invalidate_folio = netfs_invalidate_folio,
60 .migrate_folio = filemap_migrate_folio,
61 .writepages = afs_writepages,
62};
63
64const struct address_space_operations afs_symlink_aops = {
65 .read_folio = afs_symlink_read_folio,
66 .release_folio = netfs_release_folio,
67 .invalidate_folio = netfs_invalidate_folio,
68 .migrate_folio = filemap_migrate_folio,
69};
70
71static const struct vm_operations_struct afs_vm_ops = {
72 .open = afs_vm_open,
73 .close = afs_vm_close,
74 .fault = filemap_fault,
75 .map_pages = afs_vm_map_pages,
76 .page_mkwrite = afs_page_mkwrite,
77};
78
79/*
80 * Discard a pin on a writeback key.
81 */
82void afs_put_wb_key(struct afs_wb_key *wbk)
83{
84 if (wbk && refcount_dec_and_test(&wbk->usage)) {
85 key_put(wbk->key);
86 kfree(wbk);
87 }
88}
89
90/*
91 * Cache key for writeback.
92 */
93int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af)
94{
95 struct afs_wb_key *wbk, *p;
96
97 wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL);
98 if (!wbk)
99 return -ENOMEM;
100 refcount_set(&wbk->usage, 2);
101 wbk->key = af->key;
102
103 spin_lock(&vnode->wb_lock);
104 list_for_each_entry(p, &vnode->wb_keys, vnode_link) {
105 if (p->key == wbk->key)
106 goto found;
107 }
108
109 key_get(wbk->key);
110 list_add_tail(&wbk->vnode_link, &vnode->wb_keys);
111 spin_unlock(&vnode->wb_lock);
112 af->wb = wbk;
113 return 0;
114
115found:
116 refcount_inc(&p->usage);
117 spin_unlock(&vnode->wb_lock);
118 af->wb = p;
119 kfree(wbk);
120 return 0;
121}
122
123/*
124 * open an AFS file or directory and attach a key to it
125 */
126int afs_open(struct inode *inode, struct file *file)
127{
128 struct afs_vnode *vnode = AFS_FS_I(inode);
129 struct afs_file *af;
130 struct key *key;
131 int ret;
132
133 _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
134
135 key = afs_request_key(vnode->volume->cell);
136 if (IS_ERR(key)) {
137 ret = PTR_ERR(key);
138 goto error;
139 }
140
141 af = kzalloc(sizeof(*af), GFP_KERNEL);
142 if (!af) {
143 ret = -ENOMEM;
144 goto error_key;
145 }
146 af->key = key;
147
148 ret = afs_validate(vnode, key);
149 if (ret < 0)
150 goto error_af;
151
152 if (file->f_mode & FMODE_WRITE) {
153 ret = afs_cache_wb_key(vnode, af);
154 if (ret < 0)
155 goto error_af;
156 }
157
158 if (file->f_flags & O_TRUNC)
159 set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
160
161 fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE);
162
163 file->private_data = af;
164 _leave(" = 0");
165 return 0;
166
167error_af:
168 kfree(af);
169error_key:
170 key_put(key);
171error:
172 _leave(" = %d", ret);
173 return ret;
174}
175
176/*
177 * release an AFS file or directory and discard its key
178 */
179int afs_release(struct inode *inode, struct file *file)
180{
181 struct afs_vnode_cache_aux aux;
182 struct afs_vnode *vnode = AFS_FS_I(inode);
183 struct afs_file *af = file->private_data;
184 loff_t i_size;
185 int ret = 0;
186
187 _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
188
189 if ((file->f_mode & FMODE_WRITE))
190 ret = vfs_fsync(file, 0);
191
192 file->private_data = NULL;
193 if (af->wb)
194 afs_put_wb_key(af->wb);
195
196 if ((file->f_mode & FMODE_WRITE)) {
197 i_size = i_size_read(&vnode->netfs.inode);
198 afs_set_cache_aux(vnode, &aux);
199 fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size);
200 } else {
201 fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
202 }
203
204 key_put(af->key);
205 kfree(af);
206 afs_prune_wb_keys(vnode);
207 _leave(" = %d", ret);
208 return ret;
209}
210
211/*
212 * Allocate a new read record.
213 */
214struct afs_read *afs_alloc_read(gfp_t gfp)
215{
216 struct afs_read *req;
217
218 req = kzalloc(sizeof(struct afs_read), gfp);
219 if (req)
220 refcount_set(&req->usage, 1);
221
222 return req;
223}
224
225/*
226 * Dispose of a ref to a read record.
227 */
228void afs_put_read(struct afs_read *req)
229{
230 if (refcount_dec_and_test(&req->usage)) {
231 if (req->cleanup)
232 req->cleanup(req);
233 key_put(req->key);
234 kfree(req);
235 }
236}
237
238static void afs_fetch_data_notify(struct afs_operation *op)
239{
240 struct afs_read *req = op->fetch.req;
241 struct netfs_io_subrequest *subreq = req->subreq;
242 int error = afs_op_error(op);
243
244 req->error = error;
245 if (subreq) {
246 __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
247 netfs_subreq_terminated(subreq, error ?: req->actual_len, false);
248 req->subreq = NULL;
249 } else if (req->done) {
250 req->done(req);
251 }
252}
253
254static void afs_fetch_data_success(struct afs_operation *op)
255{
256 struct afs_vnode *vnode = op->file[0].vnode;
257
258 _enter("op=%08x", op->debug_id);
259 afs_vnode_commit_status(op, &op->file[0]);
260 afs_stat_v(vnode, n_fetches);
261 atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes);
262 afs_fetch_data_notify(op);
263}
264
265static void afs_fetch_data_put(struct afs_operation *op)
266{
267 op->fetch.req->error = afs_op_error(op);
268 afs_put_read(op->fetch.req);
269}
270
271static const struct afs_operation_ops afs_fetch_data_operation = {
272 .issue_afs_rpc = afs_fs_fetch_data,
273 .issue_yfs_rpc = yfs_fs_fetch_data,
274 .success = afs_fetch_data_success,
275 .aborted = afs_check_for_remote_deletion,
276 .failed = afs_fetch_data_notify,
277 .put = afs_fetch_data_put,
278};
279
280/*
281 * Fetch file data from the volume.
282 */
283int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req)
284{
285 struct afs_operation *op;
286
287 _enter("%s{%llx:%llu.%u},%x,,,",
288 vnode->volume->name,
289 vnode->fid.vid,
290 vnode->fid.vnode,
291 vnode->fid.unique,
292 key_serial(req->key));
293
294 op = afs_alloc_operation(req->key, vnode->volume);
295 if (IS_ERR(op)) {
296 if (req->subreq)
297 netfs_subreq_terminated(req->subreq, PTR_ERR(op), false);
298 return PTR_ERR(op);
299 }
300
301 afs_op_set_vnode(op, 0, vnode);
302
303 op->fetch.req = afs_get_read(req);
304 op->ops = &afs_fetch_data_operation;
305 return afs_do_sync_operation(op);
306}
307
308static void afs_issue_read(struct netfs_io_subrequest *subreq)
309{
310 struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
311 struct afs_read *fsreq;
312
313 fsreq = afs_alloc_read(GFP_NOFS);
314 if (!fsreq)
315 return netfs_subreq_terminated(subreq, -ENOMEM, false);
316
317 fsreq->subreq = subreq;
318 fsreq->pos = subreq->start + subreq->transferred;
319 fsreq->len = subreq->len - subreq->transferred;
320 fsreq->key = key_get(subreq->rreq->netfs_priv);
321 fsreq->vnode = vnode;
322 fsreq->iter = &subreq->io_iter;
323
324 afs_fetch_data(fsreq->vnode, fsreq);
325 afs_put_read(fsreq);
326}
327
328static int afs_symlink_read_folio(struct file *file, struct folio *folio)
329{
330 struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host);
331 struct afs_read *fsreq;
332 int ret;
333
334 fsreq = afs_alloc_read(GFP_NOFS);
335 if (!fsreq)
336 return -ENOMEM;
337
338 fsreq->pos = folio_pos(folio);
339 fsreq->len = folio_size(folio);
340 fsreq->vnode = vnode;
341 fsreq->iter = &fsreq->def_iter;
342 iov_iter_xarray(&fsreq->def_iter, ITER_DEST, &folio->mapping->i_pages,
343 fsreq->pos, fsreq->len);
344
345 ret = afs_fetch_data(fsreq->vnode, fsreq);
346 if (ret == 0)
347 folio_mark_uptodate(folio);
348 folio_unlock(folio);
349 return ret;
350}
351
352static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
353{
354 if (file)
355 rreq->netfs_priv = key_get(afs_file_key(file));
356 rreq->rsize = 256 * 1024;
357 rreq->wsize = 256 * 1024;
358 return 0;
359}
360
361static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len,
362 struct folio **foliop, void **_fsdata)
363{
364 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
365
366 return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0;
367}
368
369static void afs_free_request(struct netfs_io_request *rreq)
370{
371 key_put(rreq->netfs_priv);
372}
373
374static void afs_update_i_size(struct inode *inode, loff_t new_i_size)
375{
376 struct afs_vnode *vnode = AFS_FS_I(inode);
377 loff_t i_size;
378
379 write_seqlock(&vnode->cb_lock);
380 i_size = i_size_read(&vnode->netfs.inode);
381 if (new_i_size > i_size) {
382 i_size_write(&vnode->netfs.inode, new_i_size);
383 inode_set_bytes(&vnode->netfs.inode, new_i_size);
384 }
385 write_sequnlock(&vnode->cb_lock);
386 fscache_update_cookie(afs_vnode_cache(vnode), NULL, &new_i_size);
387}
388
389static void afs_netfs_invalidate_cache(struct netfs_io_request *wreq)
390{
391 struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
392
393 afs_invalidate_cache(vnode, 0);
394}
395
396const struct netfs_request_ops afs_req_ops = {
397 .init_request = afs_init_request,
398 .free_request = afs_free_request,
399 .check_write_begin = afs_check_write_begin,
400 .issue_read = afs_issue_read,
401 .update_i_size = afs_update_i_size,
402 .invalidate_cache = afs_netfs_invalidate_cache,
403 .create_write_requests = afs_create_write_requests,
404};
405
406static void afs_add_open_mmap(struct afs_vnode *vnode)
407{
408 if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) {
409 down_write(&vnode->volume->open_mmaps_lock);
410
411 if (list_empty(&vnode->cb_mmap_link))
412 list_add_tail(&vnode->cb_mmap_link, &vnode->volume->open_mmaps);
413
414 up_write(&vnode->volume->open_mmaps_lock);
415 }
416}
417
418static void afs_drop_open_mmap(struct afs_vnode *vnode)
419{
420 if (atomic_add_unless(&vnode->cb_nr_mmap, -1, 1))
421 return;
422
423 down_write(&vnode->volume->open_mmaps_lock);
424
425 read_seqlock_excl(&vnode->cb_lock);
426 // the only place where ->cb_nr_mmap may hit 0
427 // see __afs_break_callback() for the other side...
428 if (atomic_dec_and_test(&vnode->cb_nr_mmap))
429 list_del_init(&vnode->cb_mmap_link);
430 read_sequnlock_excl(&vnode->cb_lock);
431
432 up_write(&vnode->volume->open_mmaps_lock);
433 flush_work(&vnode->cb_work);
434}
435
436/*
437 * Handle setting up a memory mapping on an AFS file.
438 */
439static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
440{
441 struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
442 int ret;
443
444 afs_add_open_mmap(vnode);
445
446 ret = generic_file_mmap(file, vma);
447 if (ret == 0)
448 vma->vm_ops = &afs_vm_ops;
449 else
450 afs_drop_open_mmap(vnode);
451 return ret;
452}
453
454static void afs_vm_open(struct vm_area_struct *vma)
455{
456 afs_add_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
457}
458
459static void afs_vm_close(struct vm_area_struct *vma)
460{
461 afs_drop_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
462}
463
464static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff)
465{
466 struct afs_vnode *vnode = AFS_FS_I(file_inode(vmf->vma->vm_file));
467
468 if (afs_check_validity(vnode))
469 return filemap_map_pages(vmf, start_pgoff, end_pgoff);
470 return 0;
471}
472
473static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
474{
475 struct inode *inode = file_inode(iocb->ki_filp);
476 struct afs_vnode *vnode = AFS_FS_I(inode);
477 struct afs_file *af = iocb->ki_filp->private_data;
478 ssize_t ret;
479
480 if (iocb->ki_flags & IOCB_DIRECT)
481 return netfs_unbuffered_read_iter(iocb, iter);
482
483 ret = netfs_start_io_read(inode);
484 if (ret < 0)
485 return ret;
486 ret = afs_validate(vnode, af->key);
487 if (ret == 0)
488 ret = filemap_read(iocb, iter, 0);
489 netfs_end_io_read(inode);
490 return ret;
491}
492
493static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
494 struct pipe_inode_info *pipe,
495 size_t len, unsigned int flags)
496{
497 struct inode *inode = file_inode(in);
498 struct afs_vnode *vnode = AFS_FS_I(inode);
499 struct afs_file *af = in->private_data;
500 ssize_t ret;
501
502 ret = netfs_start_io_read(inode);
503 if (ret < 0)
504 return ret;
505 ret = afs_validate(vnode, af->key);
506 if (ret == 0)
507 ret = filemap_splice_read(in, ppos, pipe, len, flags);
508 netfs_end_io_read(inode);
509 return ret;
510}