Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/nfs/read.c | |
4 | * | |
5 | * Block I/O for NFS | |
6 | * | |
7 | * Partial copy of Linus' read cache modifications to fs/nfs/file.c | |
8 | * modified for async RPC by okir@monad.swb.de | |
1da177e4 LT |
9 | */ |
10 | ||
1da177e4 LT |
11 | #include <linux/time.h> |
12 | #include <linux/kernel.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/fcntl.h> | |
15 | #include <linux/stat.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/sunrpc/clnt.h> | |
20 | #include <linux/nfs_fs.h> | |
21 | #include <linux/nfs_page.h> | |
64419a9b | 22 | #include <linux/module.h> |
1da177e4 | 23 | |
f11c88af | 24 | #include "nfs4_fs.h" |
49a70f27 | 25 | #include "internal.h" |
91d5b470 | 26 | #include "iostat.h" |
9a9fc1c0 | 27 | #include "fscache.h" |
fab5fc25 | 28 | #include "pnfs.h" |
8224b273 | 29 | #include "nfstrace.h" |
91d5b470 | 30 | |
1da177e4 LT |
31 | #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
32 | ||
061ae2ed | 33 | static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops; |
4a0de55c | 34 | static const struct nfs_rw_ops nfs_rw_read_ops; |
1da177e4 | 35 | |
e18b890b | 36 | static struct kmem_cache *nfs_rdata_cachep; |
1da177e4 | 37 | |
1e7f3a48 | 38 | static struct nfs_pgio_header *nfs_readhdr_alloc(void) |
3feb2d49 | 39 | { |
fbe77c30 BC |
40 | struct nfs_pgio_header *p = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL); |
41 | ||
42 | if (p) | |
43 | p->rw_mode = FMODE_READ; | |
44 | return p; | |
4db6e0b7 FI |
45 | } |
46 | ||
1e7f3a48 | 47 | static void nfs_readhdr_free(struct nfs_pgio_header *rhdr) |
3feb2d49 | 48 | { |
cd841605 | 49 | kmem_cache_free(nfs_rdata_cachep, rhdr); |
3feb2d49 TM |
50 | } |
51 | ||
1da177e4 LT |
52 | static |
53 | int nfs_return_empty_page(struct page *page) | |
54 | { | |
09cbfeaf | 55 | zero_user(page, 0, PAGE_SIZE); |
1da177e4 LT |
56 | SetPageUptodate(page); |
57 | unlock_page(page); | |
58 | return 0; | |
59 | } | |
60 | ||
1abb5088 | 61 | void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, |
fab5fc25 | 62 | struct inode *inode, bool force_mds, |
061ae2ed | 63 | const struct nfs_pgio_completion_ops *compl_ops) |
1751c363 | 64 | { |
fab5fc25 | 65 | struct nfs_server *server = NFS_SERVER(inode); |
41d8d5b7 | 66 | const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops; |
fab5fc25 CH |
67 | |
68 | #ifdef CONFIG_NFS_V4_1 | |
69 | if (server->pnfs_curr_ld && !force_mds) | |
70 | pg_ops = server->pnfs_curr_ld->pg_read_ops; | |
71 | #endif | |
4a0de55c | 72 | nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_read_ops, |
3bde7afd | 73 | server->rsize, 0); |
1751c363 | 74 | } |
ddda8e0a | 75 | EXPORT_SYMBOL_GPL(nfs_pageio_init_read); |
1751c363 | 76 | |
1e83b173 DW |
77 | static void nfs_pageio_complete_read(struct nfs_pageio_descriptor *pgio, |
78 | struct inode *inode) | |
79 | { | |
80 | struct nfs_pgio_mirror *pgm; | |
81 | unsigned long npages; | |
82 | ||
83 | nfs_pageio_complete(pgio); | |
84 | ||
85 | /* It doesn't make sense to do mirrored reads! */ | |
86 | WARN_ON_ONCE(pgio->pg_mirror_count != 1); | |
87 | ||
88 | pgm = &pgio->pg_mirrors[0]; | |
89 | NFS_I(inode)->read_io += pgm->pg_bytes_written; | |
90 | npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
91 | nfs_add_stats(inode, NFSIOS_READPAGES, npages); | |
92 | } | |
93 | ||
94 | ||
493292dd TM |
95 | void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio) |
96 | { | |
a7d42ddb WAA |
97 | struct nfs_pgio_mirror *mirror; |
98 | ||
6f29b9bb KM |
99 | if (pgio->pg_ops && pgio->pg_ops->pg_cleanup) |
100 | pgio->pg_ops->pg_cleanup(pgio); | |
101 | ||
41d8d5b7 | 102 | pgio->pg_ops = &nfs_pgio_rw_ops; |
a7d42ddb WAA |
103 | |
104 | /* read path should never have more than one mirror */ | |
105 | WARN_ON_ONCE(pgio->pg_mirror_count != 1); | |
106 | ||
107 | mirror = &pgio->pg_mirrors[0]; | |
108 | mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize; | |
493292dd | 109 | } |
1f945357 | 110 | EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds); |
493292dd | 111 | |
8f54c7a4 | 112 | static void nfs_readpage_release(struct nfs_page *req, int error) |
0bcbf039 | 113 | { |
9fcd5960 | 114 | struct inode *inode = d_inode(nfs_req_openctx(req)->dentry); |
8f54c7a4 | 115 | struct page *page = req->wb_page; |
0bcbf039 PT |
116 | |
117 | dprintk("NFS: read done (%s/%llu %d@%lld)\n", inode->i_sb->s_id, | |
118 | (unsigned long long)NFS_FILEID(inode), req->wb_bytes, | |
119 | (long long)req_offset(req)); | |
120 | ||
8f54c7a4 TM |
121 | if (nfs_error_is_fatal_on_server(error) && error != -ETIMEDOUT) |
122 | SetPageError(page); | |
0bcbf039 | 123 | if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) { |
8f54c7a4 | 124 | struct address_space *mapping = page_file_mapping(page); |
0bcbf039 | 125 | |
8f54c7a4 TM |
126 | if (PageUptodate(page)) |
127 | nfs_readpage_to_fscache(inode, page, 0); | |
128 | else if (!PageError(page) && !PagePrivate(page)) | |
129 | generic_error_remove_page(mapping, page); | |
130 | unlock_page(page); | |
0bcbf039 PT |
131 | } |
132 | nfs_release_request(req); | |
133 | } | |
134 | ||
1af7e7f8 DW |
135 | struct nfs_readdesc { |
136 | struct nfs_pageio_descriptor pgio; | |
137 | struct nfs_open_context *ctx; | |
138 | }; | |
139 | ||
67d0338e WAA |
140 | static void nfs_page_group_set_uptodate(struct nfs_page *req) |
141 | { | |
142 | if (nfs_page_group_sync_on_bit(req, PG_UPTODATE)) | |
143 | SetPageUptodate(req->wb_page); | |
144 | } | |
145 | ||
061ae2ed | 146 | static void nfs_read_completion(struct nfs_pgio_header *hdr) |
4db6e0b7 FI |
147 | { |
148 | unsigned long bytes = 0; | |
8f54c7a4 | 149 | int error; |
4db6e0b7 FI |
150 | |
151 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) | |
152 | goto out; | |
4bd8b010 TM |
153 | while (!list_empty(&hdr->pages)) { |
154 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
155 | struct page *page = req->wb_page; | |
68072992 WAA |
156 | unsigned long start = req->wb_pgbase; |
157 | unsigned long end = req->wb_pgbase + req->wb_bytes; | |
4bd8b010 TM |
158 | |
159 | if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) { | |
68072992 | 160 | /* note: regions of the page not covered by a |
1e83b173 | 161 | * request are zeroed in readpage_async_filler */ |
68072992 WAA |
162 | if (bytes > hdr->good_bytes) { |
163 | /* nothing in this request was good, so zero | |
164 | * the full extent of the request */ | |
165 | zero_user_segment(page, start, end); | |
166 | ||
167 | } else if (hdr->good_bytes - bytes < req->wb_bytes) { | |
168 | /* part of this request has good bytes, but | |
169 | * not all. zero the bad bytes */ | |
170 | start += hdr->good_bytes - bytes; | |
171 | WARN_ON(start < req->wb_pgbase); | |
172 | zero_user_segment(page, start, end); | |
173 | } | |
4db6e0b7 | 174 | } |
8f54c7a4 | 175 | error = 0; |
4bd8b010 TM |
176 | bytes += req->wb_bytes; |
177 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
4db6e0b7 | 178 | if (bytes <= hdr->good_bytes) |
67d0338e | 179 | nfs_page_group_set_uptodate(req); |
8f54c7a4 TM |
180 | else { |
181 | error = hdr->error; | |
182 | xchg(&nfs_req_openctx(req)->error, error); | |
183 | } | |
4bd8b010 | 184 | } else |
67d0338e | 185 | nfs_page_group_set_uptodate(req); |
4bd8b010 | 186 | nfs_list_remove_request(req); |
8f54c7a4 | 187 | nfs_readpage_release(req, error); |
4db6e0b7 FI |
188 | } |
189 | out: | |
190 | hdr->release(hdr); | |
191 | } | |
192 | ||
d45f60c6 WAA |
193 | static void nfs_initiate_read(struct nfs_pgio_header *hdr, |
194 | struct rpc_message *msg, | |
abde71f4 | 195 | const struct nfs_rpc_ops *rpc_ops, |
1ed26f33 | 196 | struct rpc_task_setup *task_setup_data, int how) |
1da177e4 | 197 | { |
d45f60c6 | 198 | struct inode *inode = hdr->inode; |
84115e1c | 199 | int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0; |
1da177e4 | 200 | |
1ed26f33 | 201 | task_setup_data->flags |= swap_flags; |
abde71f4 | 202 | rpc_ops->read_setup(hdr, msg); |
2343172d | 203 | trace_nfs_initiate_read(hdr); |
64419a9b AA |
204 | } |
205 | ||
061ae2ed | 206 | static void |
df3accb8 | 207 | nfs_async_read_error(struct list_head *head, int error) |
1da177e4 LT |
208 | { |
209 | struct nfs_page *req; | |
210 | ||
211 | while (!list_empty(head)) { | |
212 | req = nfs_list_entry(head->next); | |
213 | nfs_list_remove_request(req); | |
8f54c7a4 | 214 | nfs_readpage_release(req, error); |
1da177e4 LT |
215 | } |
216 | } | |
217 | ||
061ae2ed FI |
218 | static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = { |
219 | .error_cleanup = nfs_async_read_error, | |
220 | .completion = nfs_read_completion, | |
221 | }; | |
222 | ||
0b671301 TM |
223 | /* |
224 | * This is the callback from RPC telling us whether a reply was | |
225 | * received or some error occurred (timeout or socket shutdown). | |
226 | */ | |
d45f60c6 WAA |
227 | static int nfs_readpage_done(struct rpc_task *task, |
228 | struct nfs_pgio_header *hdr, | |
0eecb214 | 229 | struct inode *inode) |
0b671301 | 230 | { |
d45f60c6 | 231 | int status = NFS_PROTO(inode)->read_done(task, hdr); |
0b671301 TM |
232 | if (status != 0) |
233 | return status; | |
234 | ||
d45f60c6 | 235 | nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, hdr->res.count); |
2343172d | 236 | trace_nfs_readpage_done(task, hdr); |
0b671301 TM |
237 | |
238 | if (task->tk_status == -ESTALE) { | |
93ce4af7 | 239 | nfs_set_inode_stale(inode); |
cd841605 | 240 | nfs_mark_for_revalidate(inode); |
0b671301 | 241 | } |
0b671301 TM |
242 | return 0; |
243 | } | |
244 | ||
d45f60c6 WAA |
245 | static void nfs_readpage_retry(struct rpc_task *task, |
246 | struct nfs_pgio_header *hdr) | |
0b671301 | 247 | { |
d45f60c6 WAA |
248 | struct nfs_pgio_args *argp = &hdr->args; |
249 | struct nfs_pgio_res *resp = &hdr->res; | |
0b671301 | 250 | |
0b671301 | 251 | /* This is a short read! */ |
d45f60c6 | 252 | nfs_inc_stats(hdr->inode, NFSIOS_SHORTREAD); |
fd2b6121 CL |
253 | trace_nfs_readpage_short(task, hdr); |
254 | ||
0b671301 | 255 | /* Has the server at least made some progress? */ |
4db6e0b7 | 256 | if (resp->count == 0) { |
d45f60c6 | 257 | nfs_set_pgio_error(hdr, -EIO, argp->offset); |
d61e612a | 258 | return; |
4db6e0b7 | 259 | } |
f8417b48 KM |
260 | |
261 | /* For non rpc-based layout drivers, retry-through-MDS */ | |
262 | if (!task->tk_ops) { | |
263 | hdr->pnfs_error = -EAGAIN; | |
264 | return; | |
265 | } | |
266 | ||
d45f60c6 WAA |
267 | /* Yes, so retry the read at the end of the hdr */ |
268 | hdr->mds_offset += resp->count; | |
0b671301 TM |
269 | argp->offset += resp->count; |
270 | argp->pgbase += resp->count; | |
271 | argp->count -= resp->count; | |
8c9cb714 TM |
272 | resp->count = 0; |
273 | resp->eof = 0; | |
d00c5d43 | 274 | rpc_restart_call_prepare(task); |
0b671301 TM |
275 | } |
276 | ||
d45f60c6 WAA |
277 | static void nfs_readpage_result(struct rpc_task *task, |
278 | struct nfs_pgio_header *hdr) | |
1da177e4 | 279 | { |
d45f60c6 | 280 | if (hdr->res.eof) { |
1c6c4b74 TM |
281 | loff_t pos = hdr->args.offset + hdr->res.count; |
282 | unsigned int new = pos - hdr->io_start; | |
4db6e0b7 | 283 | |
1c6c4b74 TM |
284 | if (hdr->good_bytes > new) { |
285 | hdr->good_bytes = new; | |
4db6e0b7 FI |
286 | set_bit(NFS_IOHDR_EOF, &hdr->flags); |
287 | clear_bit(NFS_IOHDR_ERROR, &hdr->flags); | |
4db6e0b7 | 288 | } |
f8417b48 | 289 | } else if (hdr->res.count < hdr->args.count) |
d45f60c6 | 290 | nfs_readpage_retry(task, hdr); |
fdd1e74c TM |
291 | } |
292 | ||
1e83b173 DW |
293 | static int |
294 | readpage_async_filler(void *data, struct page *page) | |
295 | { | |
296 | struct nfs_readdesc *desc = data; | |
297 | struct nfs_page *new; | |
298 | unsigned int len; | |
299 | int error; | |
300 | ||
301 | len = nfs_page_length(page); | |
302 | if (len == 0) | |
303 | return nfs_return_empty_page(page); | |
304 | ||
305 | new = nfs_create_request(desc->ctx, page, 0, len); | |
306 | if (IS_ERR(new)) | |
307 | goto out_error; | |
308 | ||
309 | if (len < PAGE_SIZE) | |
310 | zero_user_segment(page, len, PAGE_SIZE); | |
311 | if (!nfs_pageio_add_request(&desc->pgio, new)) { | |
312 | nfs_list_remove_request(new); | |
313 | error = desc->pgio.pg_error; | |
314 | nfs_readpage_release(new, error); | |
315 | goto out; | |
316 | } | |
317 | return 0; | |
318 | out_error: | |
319 | error = PTR_ERR(new); | |
320 | unlock_page(page); | |
321 | out: | |
322 | return error; | |
323 | } | |
324 | ||
1da177e4 LT |
325 | /* |
326 | * Read a page over NFS. | |
327 | * We read the page synchronously in the following case: | |
328 | * - The error flag is set for this page. This happens only when a | |
329 | * previous async read operation failed. | |
330 | */ | |
331 | int nfs_readpage(struct file *file, struct page *page) | |
332 | { | |
1af7e7f8 | 333 | struct nfs_readdesc desc; |
d56b4ddf | 334 | struct inode *inode = page_file_mapping(page)->host; |
49dee700 | 335 | int ret; |
1da177e4 LT |
336 | |
337 | dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", | |
8cd79788 | 338 | page, PAGE_SIZE, page_index(page)); |
91d5b470 | 339 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); |
91d5b470 | 340 | |
1da177e4 LT |
341 | /* |
342 | * Try to flush any pending writes to the file.. | |
343 | * | |
344 | * NOTE! Because we own the page lock, there cannot | |
345 | * be any new pending writes generated at this point | |
346 | * for this page (other pages can be written to). | |
347 | */ | |
49dee700 DW |
348 | ret = nfs_wb_page(inode, page); |
349 | if (ret) | |
de05a0cc TM |
350 | goto out_unlock; |
351 | if (PageUptodate(page)) | |
352 | goto out_unlock; | |
1da177e4 | 353 | |
49dee700 | 354 | ret = -ESTALE; |
5f004cf2 | 355 | if (NFS_STALE(inode)) |
de05a0cc | 356 | goto out_unlock; |
5f004cf2 | 357 | |
1da177e4 | 358 | if (file == NULL) { |
49dee700 | 359 | ret = -EBADF; |
1af7e7f8 DW |
360 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
361 | if (desc.ctx == NULL) | |
de05a0cc | 362 | goto out_unlock; |
1da177e4 | 363 | } else |
1af7e7f8 | 364 | desc.ctx = get_nfs_open_context(nfs_file_open_context(file)); |
1da177e4 | 365 | |
9a9fc1c0 | 366 | if (!IS_SYNC(inode)) { |
1af7e7f8 | 367 | ret = nfs_readpage_from_fscache(desc.ctx, inode, page); |
49dee700 | 368 | if (ret == 0) |
9a9fc1c0 DH |
369 | goto out; |
370 | } | |
371 | ||
1af7e7f8 | 372 | xchg(&desc.ctx->error, 0); |
1e83b173 DW |
373 | nfs_pageio_init_read(&desc.pgio, inode, false, |
374 | &nfs_async_read_completion_ops); | |
375 | ||
376 | ret = readpage_async_filler(&desc, page); | |
377 | ||
378 | if (!ret) | |
379 | nfs_pageio_complete_read(&desc.pgio, inode); | |
380 | ||
381 | ret = desc.pgio.pg_error < 0 ? desc.pgio.pg_error : 0; | |
49dee700 DW |
382 | if (!ret) { |
383 | ret = wait_on_page_locked_killable(page); | |
384 | if (!PageUptodate(page) && !ret) | |
1af7e7f8 | 385 | ret = xchg(&desc.ctx->error, 0); |
8f54c7a4 | 386 | } |
9a9fc1c0 | 387 | out: |
1af7e7f8 | 388 | put_nfs_open_context(desc.ctx); |
49dee700 | 389 | return ret; |
de05a0cc | 390 | out_unlock: |
1da177e4 | 391 | unlock_page(page); |
49dee700 | 392 | return ret; |
1da177e4 LT |
393 | } |
394 | ||
49dee700 | 395 | int nfs_readpages(struct file *file, struct address_space *mapping, |
1da177e4 LT |
396 | struct list_head *pages, unsigned nr_pages) |
397 | { | |
49dee700 | 398 | struct nfs_readdesc desc; |
1da177e4 | 399 | struct inode *inode = mapping->host; |
49dee700 | 400 | int ret; |
1da177e4 | 401 | |
1e8968c5 | 402 | dprintk("NFS: nfs_readpages (%s/%Lu %d)\n", |
1da177e4 | 403 | inode->i_sb->s_id, |
1e8968c5 | 404 | (unsigned long long)NFS_FILEID(inode), |
1da177e4 | 405 | nr_pages); |
91d5b470 | 406 | nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); |
1da177e4 | 407 | |
49dee700 | 408 | ret = -ESTALE; |
5f004cf2 TM |
409 | if (NFS_STALE(inode)) |
410 | goto out; | |
411 | ||
49dee700 DW |
412 | if (file == NULL) { |
413 | ret = -EBADF; | |
d530838b | 414 | desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ); |
1da177e4 | 415 | if (desc.ctx == NULL) |
49dee700 | 416 | goto out; |
1da177e4 | 417 | } else |
49dee700 | 418 | desc.ctx = get_nfs_open_context(nfs_file_open_context(file)); |
9a9fc1c0 DH |
419 | |
420 | /* attempt to read as many of the pages as possible from the cache | |
421 | * - this returns -ENOBUFS immediately if the cookie is negative | |
422 | */ | |
423 | ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping, | |
424 | pages, &nr_pages); | |
425 | if (ret == 0) | |
426 | goto read_complete; /* all pages were read */ | |
427 | ||
1af7e7f8 | 428 | nfs_pageio_init_read(&desc.pgio, inode, false, |
fab5fc25 | 429 | &nfs_async_read_completion_ops); |
8b09bee3 | 430 | |
1da177e4 | 431 | ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc); |
a7d42ddb | 432 | |
1e83b173 | 433 | nfs_pageio_complete_read(&desc.pgio, inode); |
a7d42ddb | 434 | |
9a9fc1c0 | 435 | read_complete: |
1da177e4 | 436 | put_nfs_open_context(desc.ctx); |
5f004cf2 | 437 | out: |
1da177e4 LT |
438 | return ret; |
439 | } | |
440 | ||
f7b422b1 | 441 | int __init nfs_init_readpagecache(void) |
1da177e4 LT |
442 | { |
443 | nfs_rdata_cachep = kmem_cache_create("nfs_read_data", | |
1e7f3a48 | 444 | sizeof(struct nfs_pgio_header), |
1da177e4 | 445 | 0, SLAB_HWCACHE_ALIGN, |
20c2df83 | 446 | NULL); |
1da177e4 LT |
447 | if (nfs_rdata_cachep == NULL) |
448 | return -ENOMEM; | |
449 | ||
1da177e4 LT |
450 | return 0; |
451 | } | |
452 | ||
266bee88 | 453 | void nfs_destroy_readpagecache(void) |
1da177e4 | 454 | { |
1a1d92c1 | 455 | kmem_cache_destroy(nfs_rdata_cachep); |
1da177e4 | 456 | } |
4a0de55c AS |
457 | |
458 | static const struct nfs_rw_ops nfs_rw_read_ops = { | |
459 | .rw_alloc_header = nfs_readhdr_alloc, | |
460 | .rw_free_header = nfs_readhdr_free, | |
0eecb214 AS |
461 | .rw_done = nfs_readpage_done, |
462 | .rw_result = nfs_readpage_result, | |
1ed26f33 | 463 | .rw_initiate = nfs_initiate_read, |
4a0de55c | 464 | }; |