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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 if (!file) {
267 if (WARN_ON_ONCE(rreq->origin != NETFS_PGPRIV2_COPY_TO_CACHE))
268 return -EIO;
269 return 0;
270 }
271
272 rreq->netfs_priv = get_nfs_open_context(nfs_file_open_context(file));
273 rreq->debug_id = atomic_inc_return(&nfs_netfs_debug_id);
274 /* [DEPRECATED] Use PG_private_2 to mark folio being written to the cache. */
275 __set_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags);
276 rreq->io_streams[0].sreq_max_len = NFS_SB(rreq->inode->i_sb)->rsize;
277
278 return 0;
279}
280
281static void nfs_netfs_free_request(struct netfs_io_request *rreq)
282{
283 if (rreq->netfs_priv)
284 put_nfs_open_context(rreq->netfs_priv);
285}
286
287static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sreq)
288{
289 struct nfs_netfs_io_data *netfs;
290
291 netfs = kzalloc(sizeof(*netfs), GFP_KERNEL_ACCOUNT);
292 if (!netfs)
293 return NULL;
294 netfs->sreq = sreq;
295 refcount_set(&netfs->refcount, 1);
296 return netfs;
297}
298
299static void nfs_netfs_issue_read(struct netfs_io_subrequest *sreq)
300{
301 struct nfs_netfs_io_data *netfs;
302 struct nfs_pageio_descriptor pgio;
303 struct inode *inode = sreq->rreq->inode;
304 struct nfs_open_context *ctx = sreq->rreq->netfs_priv;
305 struct page *page;
306 unsigned long idx;
307 pgoff_t start, last;
308 int err;
309
310 start = (sreq->start + sreq->transferred) >> PAGE_SHIFT;
311 last = ((sreq->start + sreq->len - sreq->transferred - 1) >> PAGE_SHIFT);
312
313 nfs_pageio_init_read(&pgio, inode, false,
314 &nfs_async_read_completion_ops);
315
316 netfs = nfs_netfs_alloc(sreq);
317 if (!netfs)
318 return netfs_read_subreq_terminated(sreq, -ENOMEM, false);
319
320 pgio.pg_netfs = netfs; /* used in completion */
321
322 xa_for_each_range(&sreq->rreq->mapping->i_pages, idx, page, start, last) {
323 /* nfs_read_add_folio() may schedule() due to pNFS layout and other RPCs */
324 err = nfs_read_add_folio(&pgio, ctx, page_folio(page));
325 if (err < 0) {
326 netfs->error = err;
327 goto out;
328 }
329 }
330out:
331 nfs_pageio_complete_read(&pgio);
332 nfs_netfs_put(netfs);
333}
334
335void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr)
336{
337 struct nfs_netfs_io_data *netfs = hdr->netfs;
338
339 if (!netfs)
340 return;
341
342 nfs_netfs_get(netfs);
343}
344
345int nfs_netfs_folio_unlock(struct folio *folio)
346{
347 struct inode *inode = folio->mapping->host;
348
349 /*
350 * If fscache is enabled, netfs will unlock pages.
351 */
352 if (netfs_inode(inode)->cache)
353 return 0;
354
355 return 1;
356}
357
358void nfs_netfs_read_completion(struct nfs_pgio_header *hdr)
359{
360 struct nfs_netfs_io_data *netfs = hdr->netfs;
361 struct netfs_io_subrequest *sreq;
362
363 if (!netfs)
364 return;
365
366 sreq = netfs->sreq;
367 if (test_bit(NFS_IOHDR_EOF, &hdr->flags) &&
368 sreq->rreq->origin != NETFS_DIO_READ)
369 __set_bit(NETFS_SREQ_CLEAR_TAIL, &sreq->flags);
370
371 if (hdr->error)
372 netfs->error = hdr->error;
373 else
374 atomic64_add(hdr->res.count, &netfs->transferred);
375
376 nfs_netfs_put(netfs);
377 hdr->netfs = NULL;
378}
379
380const struct netfs_request_ops nfs_netfs_ops = {
381 .init_request = nfs_netfs_init_request,
382 .free_request = nfs_netfs_free_request,
383 .issue_read = nfs_netfs_issue_read,
384};
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
19#include "internal.h"
20#include "iostat.h"
21#include "fscache.h"
22
23#define NFSDBG_FACILITY NFSDBG_FSCACHE
24
25static struct rb_root nfs_fscache_keys = RB_ROOT;
26static DEFINE_SPINLOCK(nfs_fscache_keys_lock);
27
28/*
29 * Layout of the key for an NFS server cache object.
30 */
31struct nfs_server_key {
32 struct {
33 uint16_t nfsversion; /* NFS protocol version */
34 uint16_t family; /* address family */
35 __be16 port; /* IP port */
36 } hdr;
37 union {
38 struct in_addr ipv4_addr; /* IPv4 address */
39 struct in6_addr ipv6_addr; /* IPv6 address */
40 };
41} __packed;
42
43/*
44 * Get the per-client index cookie for an NFS client if the appropriate mount
45 * flag was set
46 * - We always try and get an index cookie for the client, but get filehandle
47 * cookies on a per-superblock basis, depending on the mount flags
48 */
49void nfs_fscache_get_client_cookie(struct nfs_client *clp)
50{
51 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr;
52 const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr;
53 struct nfs_server_key key;
54 uint16_t len = sizeof(key.hdr);
55
56 memset(&key, 0, sizeof(key));
57 key.hdr.nfsversion = clp->rpc_ops->version;
58 key.hdr.family = clp->cl_addr.ss_family;
59
60 switch (clp->cl_addr.ss_family) {
61 case AF_INET:
62 key.hdr.port = sin->sin_port;
63 key.ipv4_addr = sin->sin_addr;
64 len += sizeof(key.ipv4_addr);
65 break;
66
67 case AF_INET6:
68 key.hdr.port = sin6->sin6_port;
69 key.ipv6_addr = sin6->sin6_addr;
70 len += sizeof(key.ipv6_addr);
71 break;
72
73 default:
74 printk(KERN_WARNING "NFS: Unknown network family '%d'\n",
75 clp->cl_addr.ss_family);
76 clp->fscache = NULL;
77 return;
78 }
79
80 /* create a cache index for looking up filehandles */
81 clp->fscache = fscache_acquire_cookie(nfs_fscache_netfs.primary_index,
82 &nfs_fscache_server_index_def,
83 &key, len,
84 NULL, 0,
85 clp, 0, true);
86 dfprintk(FSCACHE, "NFS: get client cookie (0x%p/0x%p)\n",
87 clp, clp->fscache);
88}
89
90/*
91 * Dispose of a per-client cookie
92 */
93void nfs_fscache_release_client_cookie(struct nfs_client *clp)
94{
95 dfprintk(FSCACHE, "NFS: releasing client cookie (0x%p/0x%p)\n",
96 clp, clp->fscache);
97
98 fscache_relinquish_cookie(clp->fscache, NULL, false);
99 clp->fscache = NULL;
100}
101
102/*
103 * Get the cache cookie for an NFS superblock. We have to handle
104 * uniquification here because the cache doesn't do it for us.
105 *
106 * The default uniquifier is just an empty string, but it may be overridden
107 * either by the 'fsc=xxx' option to mount, or by inheriting it from the parent
108 * superblock across an automount point of some nature.
109 */
110void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen)
111{
112 struct nfs_fscache_key *key, *xkey;
113 struct nfs_server *nfss = NFS_SB(sb);
114 struct rb_node **p, *parent;
115 int diff;
116
117 nfss->fscache_key = NULL;
118 nfss->fscache = NULL;
119 if (!(nfss->options & NFS_OPTION_FSCACHE))
120 return;
121 if (!uniq) {
122 uniq = "";
123 ulen = 1;
124 }
125
126 key = kzalloc(sizeof(*key) + ulen, GFP_KERNEL);
127 if (!key)
128 return;
129
130 key->nfs_client = nfss->nfs_client;
131 key->key.super.s_flags = sb->s_flags & NFS_MS_MASK;
132 key->key.nfs_server.flags = nfss->flags;
133 key->key.nfs_server.rsize = nfss->rsize;
134 key->key.nfs_server.wsize = nfss->wsize;
135 key->key.nfs_server.acregmin = nfss->acregmin;
136 key->key.nfs_server.acregmax = nfss->acregmax;
137 key->key.nfs_server.acdirmin = nfss->acdirmin;
138 key->key.nfs_server.acdirmax = nfss->acdirmax;
139 key->key.nfs_server.fsid = nfss->fsid;
140 key->key.rpc_auth.au_flavor = nfss->client->cl_auth->au_flavor;
141
142 key->key.uniq_len = ulen;
143 memcpy(key->key.uniquifier, uniq, ulen);
144
145 spin_lock(&nfs_fscache_keys_lock);
146 p = &nfs_fscache_keys.rb_node;
147 parent = NULL;
148 while (*p) {
149 parent = *p;
150 xkey = rb_entry(parent, struct nfs_fscache_key, node);
151
152 if (key->nfs_client < xkey->nfs_client)
153 goto go_left;
154 if (key->nfs_client > xkey->nfs_client)
155 goto go_right;
156
157 diff = memcmp(&key->key, &xkey->key, sizeof(key->key));
158 if (diff < 0)
159 goto go_left;
160 if (diff > 0)
161 goto go_right;
162
163 if (key->key.uniq_len == 0)
164 goto non_unique;
165 diff = memcmp(key->key.uniquifier,
166 xkey->key.uniquifier,
167 key->key.uniq_len);
168 if (diff < 0)
169 goto go_left;
170 if (diff > 0)
171 goto go_right;
172 goto non_unique;
173
174 go_left:
175 p = &(*p)->rb_left;
176 continue;
177 go_right:
178 p = &(*p)->rb_right;
179 }
180
181 rb_link_node(&key->node, parent, p);
182 rb_insert_color(&key->node, &nfs_fscache_keys);
183 spin_unlock(&nfs_fscache_keys_lock);
184 nfss->fscache_key = key;
185
186 /* create a cache index for looking up filehandles */
187 nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache,
188 &nfs_fscache_super_index_def,
189 key, sizeof(*key) + ulen,
190 NULL, 0,
191 nfss, 0, true);
192 dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n",
193 nfss, nfss->fscache);
194 return;
195
196non_unique:
197 spin_unlock(&nfs_fscache_keys_lock);
198 kfree(key);
199 nfss->fscache_key = NULL;
200 nfss->fscache = NULL;
201 printk(KERN_WARNING "NFS:"
202 " Cache request denied due to non-unique superblock keys\n");
203}
204
205/*
206 * release a per-superblock cookie
207 */
208void nfs_fscache_release_super_cookie(struct super_block *sb)
209{
210 struct nfs_server *nfss = NFS_SB(sb);
211
212 dfprintk(FSCACHE, "NFS: releasing superblock cookie (0x%p/0x%p)\n",
213 nfss, nfss->fscache);
214
215 fscache_relinquish_cookie(nfss->fscache, NULL, false);
216 nfss->fscache = NULL;
217
218 if (nfss->fscache_key) {
219 spin_lock(&nfs_fscache_keys_lock);
220 rb_erase(&nfss->fscache_key->node, &nfs_fscache_keys);
221 spin_unlock(&nfs_fscache_keys_lock);
222 kfree(nfss->fscache_key);
223 nfss->fscache_key = NULL;
224 }
225}
226
227/*
228 * Initialise the per-inode cache cookie pointer for an NFS inode.
229 */
230void nfs_fscache_init_inode(struct inode *inode)
231{
232 struct nfs_fscache_inode_auxdata auxdata;
233 struct nfs_server *nfss = NFS_SERVER(inode);
234 struct nfs_inode *nfsi = NFS_I(inode);
235
236 nfsi->fscache = NULL;
237 if (!(nfss->fscache && S_ISREG(inode->i_mode)))
238 return;
239
240 memset(&auxdata, 0, sizeof(auxdata));
241 auxdata.mtime = timespec64_to_timespec(nfsi->vfs_inode.i_mtime);
242 auxdata.ctime = timespec64_to_timespec(nfsi->vfs_inode.i_ctime);
243
244 if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
245 auxdata.change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
246
247 nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
248 &nfs_fscache_inode_object_def,
249 nfsi->fh.data, nfsi->fh.size,
250 &auxdata, sizeof(auxdata),
251 nfsi, nfsi->vfs_inode.i_size, false);
252}
253
254/*
255 * Release a per-inode cookie.
256 */
257void nfs_fscache_clear_inode(struct inode *inode)
258{
259 struct nfs_fscache_inode_auxdata auxdata;
260 struct nfs_inode *nfsi = NFS_I(inode);
261 struct fscache_cookie *cookie = nfs_i_fscache(inode);
262
263 dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie);
264
265 memset(&auxdata, 0, sizeof(auxdata));
266 auxdata.mtime = timespec64_to_timespec(nfsi->vfs_inode.i_mtime);
267 auxdata.ctime = timespec64_to_timespec(nfsi->vfs_inode.i_ctime);
268 fscache_relinquish_cookie(cookie, &auxdata, false);
269 nfsi->fscache = NULL;
270}
271
272static bool nfs_fscache_can_enable(void *data)
273{
274 struct inode *inode = data;
275
276 return !inode_is_open_for_write(inode);
277}
278
279/*
280 * Enable or disable caching for a file that is being opened as appropriate.
281 * The cookie is allocated when the inode is initialised, but is not enabled at
282 * that time. Enablement is deferred to file-open time to avoid stat() and
283 * access() thrashing the cache.
284 *
285 * For now, with NFS, only regular files that are open read-only will be able
286 * to use the cache.
287 *
288 * We enable the cache for an inode if we open it read-only and it isn't
289 * currently open for writing. We disable the cache if the inode is open
290 * write-only.
291 *
292 * The caller uses the file struct to pin i_writecount on the inode before
293 * calling us when a file is opened for writing, so we can make use of that.
294 *
295 * Note that this may be invoked multiple times in parallel by parallel
296 * nfs_open() functions.
297 */
298void nfs_fscache_open_file(struct inode *inode, struct file *filp)
299{
300 struct nfs_fscache_inode_auxdata auxdata;
301 struct nfs_inode *nfsi = NFS_I(inode);
302 struct fscache_cookie *cookie = nfs_i_fscache(inode);
303
304 if (!fscache_cookie_valid(cookie))
305 return;
306
307 memset(&auxdata, 0, sizeof(auxdata));
308 auxdata.mtime = timespec64_to_timespec(nfsi->vfs_inode.i_mtime);
309 auxdata.ctime = timespec64_to_timespec(nfsi->vfs_inode.i_ctime);
310
311 if (inode_is_open_for_write(inode)) {
312 dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi);
313 clear_bit(NFS_INO_FSCACHE, &nfsi->flags);
314 fscache_disable_cookie(cookie, &auxdata, true);
315 fscache_uncache_all_inode_pages(cookie, inode);
316 } else {
317 dfprintk(FSCACHE, "NFS: nfsi 0x%p enabling cache\n", nfsi);
318 fscache_enable_cookie(cookie, &auxdata, nfsi->vfs_inode.i_size,
319 nfs_fscache_can_enable, inode);
320 if (fscache_cookie_enabled(cookie))
321 set_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags);
322 }
323}
324EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
325
326/*
327 * Release the caching state associated with a page, if the page isn't busy
328 * interacting with the cache.
329 * - Returns true (can release page) or false (page busy).
330 */
331int nfs_fscache_release_page(struct page *page, gfp_t gfp)
332{
333 if (PageFsCache(page)) {
334 struct fscache_cookie *cookie = nfs_i_fscache(page->mapping->host);
335
336 BUG_ON(!cookie);
337 dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n",
338 cookie, page, NFS_I(page->mapping->host));
339
340 if (!fscache_maybe_release_page(cookie, page, gfp))
341 return 0;
342
343 nfs_inc_fscache_stats(page->mapping->host,
344 NFSIOS_FSCACHE_PAGES_UNCACHED);
345 }
346
347 return 1;
348}
349
350/*
351 * Release the caching state associated with a page if undergoing complete page
352 * invalidation.
353 */
354void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
355{
356 struct fscache_cookie *cookie = nfs_i_fscache(inode);
357
358 BUG_ON(!cookie);
359
360 dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n",
361 cookie, page, NFS_I(inode));
362
363 fscache_wait_on_page_write(cookie, page);
364
365 BUG_ON(!PageLocked(page));
366 fscache_uncache_page(cookie, page);
367 nfs_inc_fscache_stats(page->mapping->host,
368 NFSIOS_FSCACHE_PAGES_UNCACHED);
369}
370
371/*
372 * Handle completion of a page being read from the cache.
373 * - Called in process (keventd) context.
374 */
375static void nfs_readpage_from_fscache_complete(struct page *page,
376 void *context,
377 int error)
378{
379 dfprintk(FSCACHE,
380 "NFS: readpage_from_fscache_complete (0x%p/0x%p/%d)\n",
381 page, context, error);
382
383 /* if the read completes with an error, we just unlock the page and let
384 * the VM reissue the readpage */
385 if (!error) {
386 SetPageUptodate(page);
387 unlock_page(page);
388 } else {
389 error = nfs_readpage_async(context, page->mapping->host, page);
390 if (error)
391 unlock_page(page);
392 }
393}
394
395/*
396 * Retrieve a page from fscache
397 */
398int __nfs_readpage_from_fscache(struct nfs_open_context *ctx,
399 struct inode *inode, struct page *page)
400{
401 int ret;
402
403 dfprintk(FSCACHE,
404 "NFS: readpage_from_fscache(fsc:%p/p:%p(i:%lx f:%lx)/0x%p)\n",
405 nfs_i_fscache(inode), page, page->index, page->flags, inode);
406
407 ret = fscache_read_or_alloc_page(nfs_i_fscache(inode),
408 page,
409 nfs_readpage_from_fscache_complete,
410 ctx,
411 GFP_KERNEL);
412
413 switch (ret) {
414 case 0: /* read BIO submitted (page in fscache) */
415 dfprintk(FSCACHE,
416 "NFS: readpage_from_fscache: BIO submitted\n");
417 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
418 return ret;
419
420 case -ENOBUFS: /* inode not in cache */
421 case -ENODATA: /* page not in cache */
422 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
423 dfprintk(FSCACHE,
424 "NFS: readpage_from_fscache %d\n", ret);
425 return 1;
426
427 default:
428 dfprintk(FSCACHE, "NFS: readpage_from_fscache %d\n", ret);
429 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
430 }
431 return ret;
432}
433
434/*
435 * Retrieve a set of pages from fscache
436 */
437int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
438 struct inode *inode,
439 struct address_space *mapping,
440 struct list_head *pages,
441 unsigned *nr_pages)
442{
443 unsigned npages = *nr_pages;
444 int ret;
445
446 dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n",
447 nfs_i_fscache(inode), npages, inode);
448
449 ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode),
450 mapping, pages, nr_pages,
451 nfs_readpage_from_fscache_complete,
452 ctx,
453 mapping_gfp_mask(mapping));
454 if (*nr_pages < npages)
455 nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK,
456 npages);
457 if (*nr_pages > 0)
458 nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL,
459 *nr_pages);
460
461 switch (ret) {
462 case 0: /* read submitted to the cache for all pages */
463 BUG_ON(!list_empty(pages));
464 BUG_ON(*nr_pages != 0);
465 dfprintk(FSCACHE,
466 "NFS: nfs_getpages_from_fscache: submitted\n");
467
468 return ret;
469
470 case -ENOBUFS: /* some pages aren't cached and can't be */
471 case -ENODATA: /* some pages aren't cached */
472 dfprintk(FSCACHE,
473 "NFS: nfs_getpages_from_fscache: no page: %d\n", ret);
474 return 1;
475
476 default:
477 dfprintk(FSCACHE,
478 "NFS: nfs_getpages_from_fscache: ret %d\n", ret);
479 }
480
481 return ret;
482}
483
484/*
485 * Store a newly fetched page in fscache
486 * - PG_fscache must be set on the page
487 */
488void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync)
489{
490 int ret;
491
492 dfprintk(FSCACHE,
493 "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n",
494 nfs_i_fscache(inode), page, page->index, page->flags, sync);
495
496 ret = fscache_write_page(nfs_i_fscache(inode), page,
497 inode->i_size, GFP_KERNEL);
498 dfprintk(FSCACHE,
499 "NFS: readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n",
500 page, page->index, page->flags, ret);
501
502 if (ret != 0) {
503 fscache_uncache_page(nfs_i_fscache(inode), page);
504 nfs_inc_fscache_stats(inode,
505 NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
506 nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
507 } else {
508 nfs_inc_fscache_stats(inode,
509 NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
510 }
511}