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1/* NFS filesystem cache interface
2 *
3 * Copyright (C) 2008 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 Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/sched.h>
15#include <linux/mm.h>
16#include <linux/nfs_fs.h>
17#include <linux/nfs_fs_sb.h>
18#include <linux/in6.h>
19#include <linux/seq_file.h>
20#include <linux/slab.h>
21
22#include "internal.h"
23#include "iostat.h"
24#include "fscache.h"
25
26#define NFSDBG_FACILITY NFSDBG_FSCACHE
27
28static struct rb_root nfs_fscache_keys = RB_ROOT;
29static DEFINE_SPINLOCK(nfs_fscache_keys_lock);
30
31/*
32 * Get the per-client index cookie for an NFS client if the appropriate mount
33 * flag was set
34 * - We always try and get an index cookie for the client, but get filehandle
35 * cookies on a per-superblock basis, depending on the mount flags
36 */
37void nfs_fscache_get_client_cookie(struct nfs_client *clp)
38{
39 /* create a cache index for looking up filehandles */
40 clp->fscache = fscache_acquire_cookie(nfs_fscache_netfs.primary_index,
41 &nfs_fscache_server_index_def,
42 clp, true);
43 dfprintk(FSCACHE, "NFS: get client cookie (0x%p/0x%p)\n",
44 clp, clp->fscache);
45}
46
47/*
48 * Dispose of a per-client cookie
49 */
50void nfs_fscache_release_client_cookie(struct nfs_client *clp)
51{
52 dfprintk(FSCACHE, "NFS: releasing client cookie (0x%p/0x%p)\n",
53 clp, clp->fscache);
54
55 fscache_relinquish_cookie(clp->fscache, 0);
56 clp->fscache = NULL;
57}
58
59/*
60 * Get the cache cookie for an NFS superblock. We have to handle
61 * uniquification here because the cache doesn't do it for us.
62 *
63 * The default uniquifier is just an empty string, but it may be overridden
64 * either by the 'fsc=xxx' option to mount, or by inheriting it from the parent
65 * superblock across an automount point of some nature.
66 */
67void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen)
68{
69 struct nfs_fscache_key *key, *xkey;
70 struct nfs_server *nfss = NFS_SB(sb);
71 struct rb_node **p, *parent;
72 int diff;
73
74 if (!uniq) {
75 uniq = "";
76 ulen = 1;
77 }
78
79 key = kzalloc(sizeof(*key) + ulen, GFP_KERNEL);
80 if (!key)
81 return;
82
83 key->nfs_client = nfss->nfs_client;
84 key->key.super.s_flags = sb->s_flags & NFS_MS_MASK;
85 key->key.nfs_server.flags = nfss->flags;
86 key->key.nfs_server.rsize = nfss->rsize;
87 key->key.nfs_server.wsize = nfss->wsize;
88 key->key.nfs_server.acregmin = nfss->acregmin;
89 key->key.nfs_server.acregmax = nfss->acregmax;
90 key->key.nfs_server.acdirmin = nfss->acdirmin;
91 key->key.nfs_server.acdirmax = nfss->acdirmax;
92 key->key.nfs_server.fsid = nfss->fsid;
93 key->key.rpc_auth.au_flavor = nfss->client->cl_auth->au_flavor;
94
95 key->key.uniq_len = ulen;
96 memcpy(key->key.uniquifier, uniq, ulen);
97
98 spin_lock(&nfs_fscache_keys_lock);
99 p = &nfs_fscache_keys.rb_node;
100 parent = NULL;
101 while (*p) {
102 parent = *p;
103 xkey = rb_entry(parent, struct nfs_fscache_key, node);
104
105 if (key->nfs_client < xkey->nfs_client)
106 goto go_left;
107 if (key->nfs_client > xkey->nfs_client)
108 goto go_right;
109
110 diff = memcmp(&key->key, &xkey->key, sizeof(key->key));
111 if (diff < 0)
112 goto go_left;
113 if (diff > 0)
114 goto go_right;
115
116 if (key->key.uniq_len == 0)
117 goto non_unique;
118 diff = memcmp(key->key.uniquifier,
119 xkey->key.uniquifier,
120 key->key.uniq_len);
121 if (diff < 0)
122 goto go_left;
123 if (diff > 0)
124 goto go_right;
125 goto non_unique;
126
127 go_left:
128 p = &(*p)->rb_left;
129 continue;
130 go_right:
131 p = &(*p)->rb_right;
132 }
133
134 rb_link_node(&key->node, parent, p);
135 rb_insert_color(&key->node, &nfs_fscache_keys);
136 spin_unlock(&nfs_fscache_keys_lock);
137 nfss->fscache_key = key;
138
139 /* create a cache index for looking up filehandles */
140 nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache,
141 &nfs_fscache_super_index_def,
142 nfss, true);
143 dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n",
144 nfss, nfss->fscache);
145 return;
146
147non_unique:
148 spin_unlock(&nfs_fscache_keys_lock);
149 kfree(key);
150 nfss->fscache_key = NULL;
151 nfss->fscache = NULL;
152 printk(KERN_WARNING "NFS:"
153 " Cache request denied due to non-unique superblock keys\n");
154}
155
156/*
157 * release a per-superblock cookie
158 */
159void nfs_fscache_release_super_cookie(struct super_block *sb)
160{
161 struct nfs_server *nfss = NFS_SB(sb);
162
163 dfprintk(FSCACHE, "NFS: releasing superblock cookie (0x%p/0x%p)\n",
164 nfss, nfss->fscache);
165
166 fscache_relinquish_cookie(nfss->fscache, 0);
167 nfss->fscache = NULL;
168
169 if (nfss->fscache_key) {
170 spin_lock(&nfs_fscache_keys_lock);
171 rb_erase(&nfss->fscache_key->node, &nfs_fscache_keys);
172 spin_unlock(&nfs_fscache_keys_lock);
173 kfree(nfss->fscache_key);
174 nfss->fscache_key = NULL;
175 }
176}
177
178/*
179 * Initialise the per-inode cache cookie pointer for an NFS inode.
180 */
181void nfs_fscache_init_inode(struct inode *inode)
182{
183 struct nfs_inode *nfsi = NFS_I(inode);
184
185 nfsi->fscache = NULL;
186 if (!S_ISREG(inode->i_mode))
187 return;
188 nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
189 &nfs_fscache_inode_object_def,
190 nfsi, false);
191}
192
193/*
194 * Release a per-inode cookie.
195 */
196void nfs_fscache_clear_inode(struct inode *inode)
197{
198 struct nfs_inode *nfsi = NFS_I(inode);
199 struct fscache_cookie *cookie = nfs_i_fscache(inode);
200
201 dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie);
202
203 fscache_relinquish_cookie(cookie, false);
204 nfsi->fscache = NULL;
205}
206
207static bool nfs_fscache_can_enable(void *data)
208{
209 struct inode *inode = data;
210
211 return !inode_is_open_for_write(inode);
212}
213
214/*
215 * Enable or disable caching for a file that is being opened as appropriate.
216 * The cookie is allocated when the inode is initialised, but is not enabled at
217 * that time. Enablement is deferred to file-open time to avoid stat() and
218 * access() thrashing the cache.
219 *
220 * For now, with NFS, only regular files that are open read-only will be able
221 * to use the cache.
222 *
223 * We enable the cache for an inode if we open it read-only and it isn't
224 * currently open for writing. We disable the cache if the inode is open
225 * write-only.
226 *
227 * The caller uses the file struct to pin i_writecount on the inode before
228 * calling us when a file is opened for writing, so we can make use of that.
229 *
230 * Note that this may be invoked multiple times in parallel by parallel
231 * nfs_open() functions.
232 */
233void nfs_fscache_open_file(struct inode *inode, struct file *filp)
234{
235 struct nfs_inode *nfsi = NFS_I(inode);
236 struct fscache_cookie *cookie = nfs_i_fscache(inode);
237
238 if (!fscache_cookie_valid(cookie))
239 return;
240
241 if (inode_is_open_for_write(inode)) {
242 dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi);
243 clear_bit(NFS_INO_FSCACHE, &nfsi->flags);
244 fscache_disable_cookie(cookie, true);
245 fscache_uncache_all_inode_pages(cookie, inode);
246 } else {
247 dfprintk(FSCACHE, "NFS: nfsi 0x%p enabling cache\n", nfsi);
248 fscache_enable_cookie(cookie, nfs_fscache_can_enable, inode);
249 if (fscache_cookie_enabled(cookie))
250 set_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags);
251 }
252}
253EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
254
255/*
256 * Release the caching state associated with a page, if the page isn't busy
257 * interacting with the cache.
258 * - Returns true (can release page) or false (page busy).
259 */
260int nfs_fscache_release_page(struct page *page, gfp_t gfp)
261{
262 if (PageFsCache(page)) {
263 struct fscache_cookie *cookie = nfs_i_fscache(page->mapping->host);
264
265 BUG_ON(!cookie);
266 dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n",
267 cookie, page, NFS_I(page->mapping->host));
268
269 if (!fscache_maybe_release_page(cookie, page, gfp))
270 return 0;
271
272 nfs_inc_fscache_stats(page->mapping->host,
273 NFSIOS_FSCACHE_PAGES_UNCACHED);
274 }
275
276 return 1;
277}
278
279/*
280 * Release the caching state associated with a page if undergoing complete page
281 * invalidation.
282 */
283void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
284{
285 struct fscache_cookie *cookie = nfs_i_fscache(inode);
286
287 BUG_ON(!cookie);
288
289 dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n",
290 cookie, page, NFS_I(inode));
291
292 fscache_wait_on_page_write(cookie, page);
293
294 BUG_ON(!PageLocked(page));
295 fscache_uncache_page(cookie, page);
296 nfs_inc_fscache_stats(page->mapping->host,
297 NFSIOS_FSCACHE_PAGES_UNCACHED);
298}
299
300/*
301 * Handle completion of a page being read from the cache.
302 * - Called in process (keventd) context.
303 */
304static void nfs_readpage_from_fscache_complete(struct page *page,
305 void *context,
306 int error)
307{
308 dfprintk(FSCACHE,
309 "NFS: readpage_from_fscache_complete (0x%p/0x%p/%d)\n",
310 page, context, error);
311
312 /* if the read completes with an error, we just unlock the page and let
313 * the VM reissue the readpage */
314 if (!error) {
315 SetPageUptodate(page);
316 unlock_page(page);
317 } else {
318 error = nfs_readpage_async(context, page->mapping->host, page);
319 if (error)
320 unlock_page(page);
321 }
322}
323
324/*
325 * Retrieve a page from fscache
326 */
327int __nfs_readpage_from_fscache(struct nfs_open_context *ctx,
328 struct inode *inode, struct page *page)
329{
330 int ret;
331
332 dfprintk(FSCACHE,
333 "NFS: readpage_from_fscache(fsc:%p/p:%p(i:%lx f:%lx)/0x%p)\n",
334 nfs_i_fscache(inode), page, page->index, page->flags, inode);
335
336 ret = fscache_read_or_alloc_page(nfs_i_fscache(inode),
337 page,
338 nfs_readpage_from_fscache_complete,
339 ctx,
340 GFP_KERNEL);
341
342 switch (ret) {
343 case 0: /* read BIO submitted (page in fscache) */
344 dfprintk(FSCACHE,
345 "NFS: readpage_from_fscache: BIO submitted\n");
346 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
347 return ret;
348
349 case -ENOBUFS: /* inode not in cache */
350 case -ENODATA: /* page not in cache */
351 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
352 dfprintk(FSCACHE,
353 "NFS: readpage_from_fscache %d\n", ret);
354 return 1;
355
356 default:
357 dfprintk(FSCACHE, "NFS: readpage_from_fscache %d\n", ret);
358 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
359 }
360 return ret;
361}
362
363/*
364 * Retrieve a set of pages from fscache
365 */
366int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
367 struct inode *inode,
368 struct address_space *mapping,
369 struct list_head *pages,
370 unsigned *nr_pages)
371{
372 unsigned npages = *nr_pages;
373 int ret;
374
375 dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n",
376 nfs_i_fscache(inode), npages, inode);
377
378 ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode),
379 mapping, pages, nr_pages,
380 nfs_readpage_from_fscache_complete,
381 ctx,
382 mapping_gfp_mask(mapping));
383 if (*nr_pages < npages)
384 nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK,
385 npages);
386 if (*nr_pages > 0)
387 nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL,
388 *nr_pages);
389
390 switch (ret) {
391 case 0: /* read submitted to the cache for all pages */
392 BUG_ON(!list_empty(pages));
393 BUG_ON(*nr_pages != 0);
394 dfprintk(FSCACHE,
395 "NFS: nfs_getpages_from_fscache: submitted\n");
396
397 return ret;
398
399 case -ENOBUFS: /* some pages aren't cached and can't be */
400 case -ENODATA: /* some pages aren't cached */
401 dfprintk(FSCACHE,
402 "NFS: nfs_getpages_from_fscache: no page: %d\n", ret);
403 return 1;
404
405 default:
406 dfprintk(FSCACHE,
407 "NFS: nfs_getpages_from_fscache: ret %d\n", ret);
408 }
409
410 return ret;
411}
412
413/*
414 * Store a newly fetched page in fscache
415 * - PG_fscache must be set on the page
416 */
417void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync)
418{
419 int ret;
420
421 dfprintk(FSCACHE,
422 "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n",
423 nfs_i_fscache(inode), page, page->index, page->flags, sync);
424
425 ret = fscache_write_page(nfs_i_fscache(inode), page, GFP_KERNEL);
426 dfprintk(FSCACHE,
427 "NFS: readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n",
428 page, page->index, page->flags, ret);
429
430 if (ret != 0) {
431 fscache_uncache_page(nfs_i_fscache(inode), page);
432 nfs_inc_fscache_stats(inode,
433 NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
434 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
435 } else {
436 nfs_inc_fscache_stats(inode,
437 NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
438 }
439}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* NFS filesystem cache interface
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/sched.h>
11#include <linux/mm.h>
12#include <linux/nfs_fs.h>
13#include <linux/nfs_fs_sb.h>
14#include <linux/in6.h>
15#include <linux/seq_file.h>
16#include <linux/slab.h>
17#include <linux/iversion.h>
18#include <linux/xarray.h>
19#include <linux/fscache.h>
20#include <linux/netfs.h>
21
22#include "internal.h"
23#include "iostat.h"
24#include "fscache.h"
25#include "nfstrace.h"
26
27#define NFS_MAX_KEY_LEN 1000
28
29static bool nfs_append_int(char *key, int *_len, unsigned long long x)
30{
31 if (*_len > NFS_MAX_KEY_LEN)
32 return false;
33 if (x == 0)
34 key[(*_len)++] = ',';
35 else
36 *_len += sprintf(key + *_len, ",%llx", x);
37 return true;
38}
39
40/*
41 * Get the per-client index cookie for an NFS client if the appropriate mount
42 * flag was set
43 * - We always try and get an index cookie for the client, but get filehandle
44 * cookies on a per-superblock basis, depending on the mount flags
45 */
46static bool nfs_fscache_get_client_key(struct nfs_client *clp,
47 char *key, int *_len)
48{
49 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr;
50 const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr;
51
52 *_len += snprintf(key + *_len, NFS_MAX_KEY_LEN - *_len,
53 ",%u.%u,%x",
54 clp->rpc_ops->version,
55 clp->cl_minorversion,
56 clp->cl_addr.ss_family);
57
58 switch (clp->cl_addr.ss_family) {
59 case AF_INET:
60 if (!nfs_append_int(key, _len, sin->sin_port) ||
61 !nfs_append_int(key, _len, sin->sin_addr.s_addr))
62 return false;
63 return true;
64
65 case AF_INET6:
66 if (!nfs_append_int(key, _len, sin6->sin6_port) ||
67 !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[0]) ||
68 !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[1]) ||
69 !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[2]) ||
70 !nfs_append_int(key, _len, sin6->sin6_addr.s6_addr32[3]))
71 return false;
72 return true;
73
74 default:
75 printk(KERN_WARNING "NFS: Unknown network family '%d'\n",
76 clp->cl_addr.ss_family);
77 return false;
78 }
79}
80
81/*
82 * Get the cache cookie for an NFS superblock.
83 *
84 * The default uniquifier is just an empty string, but it may be overridden
85 * either by the 'fsc=xxx' option to mount, or by inheriting it from the parent
86 * superblock across an automount point of some nature.
87 */
88int nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen)
89{
90 struct fscache_volume *vcookie;
91 struct nfs_server *nfss = NFS_SB(sb);
92 unsigned int len = 3;
93 char *key;
94
95 if (uniq) {
96 nfss->fscache_uniq = kmemdup_nul(uniq, ulen, GFP_KERNEL);
97 if (!nfss->fscache_uniq)
98 return -ENOMEM;
99 }
100
101 key = kmalloc(NFS_MAX_KEY_LEN + 24, GFP_KERNEL);
102 if (!key)
103 return -ENOMEM;
104
105 memcpy(key, "nfs", 3);
106 if (!nfs_fscache_get_client_key(nfss->nfs_client, key, &len) ||
107 !nfs_append_int(key, &len, nfss->fsid.major) ||
108 !nfs_append_int(key, &len, nfss->fsid.minor) ||
109 !nfs_append_int(key, &len, sb->s_flags & NFS_SB_MASK) ||
110 !nfs_append_int(key, &len, nfss->flags) ||
111 !nfs_append_int(key, &len, nfss->rsize) ||
112 !nfs_append_int(key, &len, nfss->wsize) ||
113 !nfs_append_int(key, &len, nfss->acregmin) ||
114 !nfs_append_int(key, &len, nfss->acregmax) ||
115 !nfs_append_int(key, &len, nfss->acdirmin) ||
116 !nfs_append_int(key, &len, nfss->acdirmax) ||
117 !nfs_append_int(key, &len, nfss->client->cl_auth->au_flavor))
118 goto out;
119
120 if (ulen > 0) {
121 if (ulen > NFS_MAX_KEY_LEN - len)
122 goto out;
123 key[len++] = ',';
124 memcpy(key + len, uniq, ulen);
125 len += ulen;
126 }
127 key[len] = 0;
128
129 /* create a cache index for looking up filehandles */
130 vcookie = fscache_acquire_volume(key,
131 NULL, /* preferred_cache */
132 NULL, 0 /* coherency_data */);
133 if (IS_ERR(vcookie)) {
134 if (vcookie != ERR_PTR(-EBUSY)) {
135 kfree(key);
136 return PTR_ERR(vcookie);
137 }
138 pr_err("NFS: Cache volume key already in use (%s)\n", key);
139 vcookie = NULL;
140 }
141 nfss->fscache = vcookie;
142
143out:
144 kfree(key);
145 return 0;
146}
147
148/*
149 * release a per-superblock cookie
150 */
151void nfs_fscache_release_super_cookie(struct super_block *sb)
152{
153 struct nfs_server *nfss = NFS_SB(sb);
154
155 fscache_relinquish_volume(nfss->fscache, NULL, false);
156 nfss->fscache = NULL;
157 kfree(nfss->fscache_uniq);
158}
159
160/*
161 * Initialise the per-inode cache cookie pointer for an NFS inode.
162 */
163void nfs_fscache_init_inode(struct inode *inode)
164{
165 struct nfs_fscache_inode_auxdata auxdata;
166 struct nfs_server *nfss = NFS_SERVER(inode);
167 struct nfs_inode *nfsi = NFS_I(inode);
168
169 netfs_inode(inode)->cache = NULL;
170 if (!(nfss->fscache && S_ISREG(inode->i_mode)))
171 return;
172
173 nfs_fscache_update_auxdata(&auxdata, inode);
174
175 netfs_inode(inode)->cache = fscache_acquire_cookie(
176 nfss->fscache,
177 0,
178 nfsi->fh.data, /* index_key */
179 nfsi->fh.size,
180 &auxdata, /* aux_data */
181 sizeof(auxdata),
182 i_size_read(inode));
183
184 if (netfs_inode(inode)->cache)
185 mapping_set_release_always(inode->i_mapping);
186}
187
188/*
189 * Release a per-inode cookie.
190 */
191void nfs_fscache_clear_inode(struct inode *inode)
192{
193 fscache_relinquish_cookie(netfs_i_cookie(netfs_inode(inode)), false);
194 netfs_inode(inode)->cache = NULL;
195}
196
197/*
198 * Enable or disable caching for a file that is being opened as appropriate.
199 * The cookie is allocated when the inode is initialised, but is not enabled at
200 * that time. Enablement is deferred to file-open time to avoid stat() and
201 * access() thrashing the cache.
202 *
203 * For now, with NFS, only regular files that are open read-only will be able
204 * to use the cache.
205 *
206 * We enable the cache for an inode if we open it read-only and it isn't
207 * currently open for writing. We disable the cache if the inode is open
208 * write-only.
209 *
210 * The caller uses the file struct to pin i_writecount on the inode before
211 * calling us when a file is opened for writing, so we can make use of that.
212 *
213 * Note that this may be invoked multiple times in parallel by parallel
214 * nfs_open() functions.
215 */
216void nfs_fscache_open_file(struct inode *inode, struct file *filp)
217{
218 struct nfs_fscache_inode_auxdata auxdata;
219 struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
220 bool open_for_write = inode_is_open_for_write(inode);
221
222 if (!fscache_cookie_valid(cookie))
223 return;
224
225 fscache_use_cookie(cookie, open_for_write);
226 if (open_for_write) {
227 nfs_fscache_update_auxdata(&auxdata, inode);
228 fscache_invalidate(cookie, &auxdata, i_size_read(inode),
229 FSCACHE_INVAL_DIO_WRITE);
230 }
231}
232EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
233
234void nfs_fscache_release_file(struct inode *inode, struct file *filp)
235{
236 struct nfs_fscache_inode_auxdata auxdata;
237 struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
238 loff_t i_size = i_size_read(inode);
239
240 nfs_fscache_update_auxdata(&auxdata, inode);
241 fscache_unuse_cookie(cookie, &auxdata, &i_size);
242}
243
244int nfs_netfs_read_folio(struct file *file, struct folio *folio)
245{
246 if (!netfs_inode(folio_inode(folio))->cache)
247 return -ENOBUFS;
248
249 return netfs_read_folio(file, folio);
250}
251
252int nfs_netfs_readahead(struct readahead_control *ractl)
253{
254 struct inode *inode = ractl->mapping->host;
255
256 if (!netfs_inode(inode)->cache)
257 return -ENOBUFS;
258
259 netfs_readahead(ractl);
260 return 0;
261}
262
263static atomic_t nfs_netfs_debug_id;
264static int nfs_netfs_init_request(struct netfs_io_request *rreq, struct file *file)
265{
266 rreq->netfs_priv = get_nfs_open_context(nfs_file_open_context(file));
267 rreq->debug_id = atomic_inc_return(&nfs_netfs_debug_id);
268
269 return 0;
270}
271
272static void nfs_netfs_free_request(struct netfs_io_request *rreq)
273{
274 put_nfs_open_context(rreq->netfs_priv);
275}
276
277static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sreq)
278{
279 struct nfs_netfs_io_data *netfs;
280
281 netfs = kzalloc(sizeof(*netfs), GFP_KERNEL_ACCOUNT);
282 if (!netfs)
283 return NULL;
284 netfs->sreq = sreq;
285 refcount_set(&netfs->refcount, 1);
286 return netfs;
287}
288
289static bool nfs_netfs_clamp_length(struct netfs_io_subrequest *sreq)
290{
291 size_t rsize = NFS_SB(sreq->rreq->inode->i_sb)->rsize;
292
293 sreq->len = min(sreq->len, rsize);
294 return true;
295}
296
297static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq)
298{
299 struct nfs_netfs_io_data *netfs;
300 struct nfs_pageio_descriptor pgio;
301 struct inode *inode = sreq->rreq->inode;
302 struct nfs_open_context *ctx = sreq->rreq->netfs_priv;
303 struct page *page;
304 unsigned long idx;
305 int err;
306 pgoff_t start = (sreq->start + sreq->transferred) >> PAGE_SHIFT;
307 pgoff_t last = ((sreq->start + sreq->len -
308 sreq->transferred - 1) >> PAGE_SHIFT);
309
310 nfs_pageio_init_read(&pgio, inode, false,
311 &nfs_async_read_completion_ops);
312
313 netfs = nfs_netfs_alloc(sreq);
314 if (!netfs)
315 return netfs_subreq_terminated(sreq, -ENOMEM, false);
316
317 pgio.pg_netfs = netfs; /* used in completion */
318
319 xa_for_each_range(&sreq->rreq->mapping->i_pages, idx, page, start, last) {
320 /* nfs_read_add_folio() may schedule() due to pNFS layout and other RPCs */
321 err = nfs_read_add_folio(&pgio, ctx, page_folio(page));
322 if (err < 0) {
323 netfs->error = err;
324 goto out;
325 }
326 }
327out:
328 nfs_pageio_complete_read(&pgio);
329 nfs_netfs_put(netfs);
330}
331
332void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr)
333{
334 struct nfs_netfs_io_data *netfs = hdr->netfs;
335
336 if (!netfs)
337 return;
338
339 nfs_netfs_get(netfs);
340}
341
342int nfs_netfs_folio_unlock(struct folio *folio)
343{
344 struct inode *inode = folio_file_mapping(folio)->host;
345
346 /*
347 * If fscache is enabled, netfs will unlock pages.
348 */
349 if (netfs_inode(inode)->cache)
350 return 0;
351
352 return 1;
353}
354
355void nfs_netfs_read_completion(struct nfs_pgio_header *hdr)
356{
357 struct nfs_netfs_io_data *netfs = hdr->netfs;
358 struct netfs_io_subrequest *sreq;
359
360 if (!netfs)
361 return;
362
363 sreq = netfs->sreq;
364 if (test_bit(NFS_IOHDR_EOF, &hdr->flags))
365 __set_bit(NETFS_SREQ_CLEAR_TAIL, &sreq->flags);
366
367 if (hdr->error)
368 netfs->error = hdr->error;
369 else
370 atomic64_add(hdr->res.count, &netfs->transferred);
371
372 nfs_netfs_put(netfs);
373 hdr->netfs = NULL;
374}
375
376const struct netfs_request_ops nfs_netfs_ops = {
377 .init_request = nfs_netfs_init_request,
378 .free_request = nfs_netfs_free_request,
379 .issue_read = nfs_netfs_issue_read,
380 .clamp_length = nfs_netfs_clamp_length
381};