Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/nfs/direct.c | |
4 | * | |
5 | * Copyright (C) 2003 by Chuck Lever <cel@netapp.com> | |
6 | * | |
7 | * High-performance uncached I/O for the Linux NFS client | |
8 | * | |
9 | * There are important applications whose performance or correctness | |
10 | * depends on uncached access to file data. Database clusters | |
88467055 | 11 | * (multiple copies of the same instance running on separate hosts) |
1da177e4 | 12 | * implement their own cache coherency protocol that subsumes file |
88467055 CL |
13 | * system cache protocols. Applications that process datasets |
14 | * considerably larger than the client's memory do not always benefit | |
15 | * from a local cache. A streaming video server, for instance, has no | |
1da177e4 LT |
16 | * need to cache the contents of a file. |
17 | * | |
18 | * When an application requests uncached I/O, all read and write requests | |
19 | * are made directly to the server; data stored or fetched via these | |
20 | * requests is not cached in the Linux page cache. The client does not | |
21 | * correct unaligned requests from applications. All requested bytes are | |
22 | * held on permanent storage before a direct write system call returns to | |
23 | * an application. | |
24 | * | |
25 | * Solaris implements an uncached I/O facility called directio() that | |
26 | * is used for backups and sequential I/O to very large files. Solaris | |
27 | * also supports uncaching whole NFS partitions with "-o forcedirectio," | |
28 | * an undocumented mount option. | |
29 | * | |
30 | * Designed by Jeff Kimmel, Chuck Lever, and Trond Myklebust, with | |
31 | * help from Andrew Morton. | |
32 | * | |
33 | * 18 Dec 2001 Initial implementation for 2.4 --cel | |
34 | * 08 Jul 2002 Version for 2.4.19, with bug fixes --trondmy | |
35 | * 08 Jun 2003 Port to 2.5 APIs --cel | |
36 | * 31 Mar 2004 Handle direct I/O without VFS support --cel | |
37 | * 15 Sep 2004 Parallel async reads --cel | |
88467055 | 38 | * 04 May 2005 support O_DIRECT with aio --cel |
1da177e4 LT |
39 | * |
40 | */ | |
41 | ||
1da177e4 LT |
42 | #include <linux/errno.h> |
43 | #include <linux/sched.h> | |
44 | #include <linux/kernel.h> | |
1da177e4 LT |
45 | #include <linux/file.h> |
46 | #include <linux/pagemap.h> | |
47 | #include <linux/kref.h> | |
5a0e3ad6 | 48 | #include <linux/slab.h> |
7ec10f26 | 49 | #include <linux/task_io_accounting_ops.h> |
6296556f | 50 | #include <linux/module.h> |
1da177e4 LT |
51 | |
52 | #include <linux/nfs_fs.h> | |
53 | #include <linux/nfs_page.h> | |
54 | #include <linux/sunrpc/clnt.h> | |
55 | ||
7c0f6ba6 | 56 | #include <linux/uaccess.h> |
60063497 | 57 | #include <linux/atomic.h> |
1da177e4 | 58 | |
8d5658c9 | 59 | #include "internal.h" |
91d5b470 | 60 | #include "iostat.h" |
1763da12 | 61 | #include "pnfs.h" |
91d5b470 | 62 | |
1da177e4 | 63 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 | 64 | |
e18b890b | 65 | static struct kmem_cache *nfs_direct_cachep; |
1da177e4 LT |
66 | |
67 | /* | |
68 | * This represents a set of asynchronous requests that we're waiting on | |
69 | */ | |
0a00b77b WAA |
70 | struct nfs_direct_mirror { |
71 | ssize_t count; | |
72 | }; | |
73 | ||
1da177e4 LT |
74 | struct nfs_direct_req { |
75 | struct kref kref; /* release manager */ | |
15ce4a0c CL |
76 | |
77 | /* I/O parameters */ | |
a8881f5a | 78 | struct nfs_open_context *ctx; /* file open context info */ |
f11ac8db | 79 | struct nfs_lock_context *l_ctx; /* Lock context info */ |
99514f8f | 80 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 81 | struct inode * inode; /* target file of i/o */ |
15ce4a0c CL |
82 | |
83 | /* completion state */ | |
607f31e8 | 84 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 85 | spinlock_t lock; /* protect completion state */ |
0a00b77b WAA |
86 | |
87 | struct nfs_direct_mirror mirrors[NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX]; | |
88 | int mirror_count; | |
89 | ||
d9ee6553 | 90 | loff_t io_start; /* Start offset for I/O */ |
15ce4a0c | 91 | ssize_t count, /* bytes actually processed */ |
ed3743a6 | 92 | max_count, /* max expected count */ |
35754bc0 | 93 | bytes_left, /* bytes left to be sent */ |
1da177e4 | 94 | error; /* any reported error */ |
d72b7a6b | 95 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
96 | |
97 | /* commit state */ | |
1763da12 FI |
98 | struct nfs_mds_commit_info mds_cinfo; /* Storage for cinfo */ |
99 | struct pnfs_ds_commit_info ds_cinfo; /* Storage for cinfo */ | |
100 | struct work_struct work; | |
fad61490 | 101 | int flags; |
ad3cba22 | 102 | /* for write */ |
fad61490 TM |
103 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ |
104 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
ad3cba22 DK |
105 | /* for read */ |
106 | #define NFS_ODIRECT_SHOULD_DIRTY (3) /* dirty user-space page after read */ | |
fad61490 | 107 | struct nfs_writeverf verf; /* unstable write verifier */ |
1da177e4 LT |
108 | }; |
109 | ||
1763da12 FI |
110 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops; |
111 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops; | |
4d3b55d3 | 112 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq); |
1763da12 | 113 | static void nfs_direct_write_schedule_work(struct work_struct *work); |
607f31e8 TM |
114 | |
115 | static inline void get_dreq(struct nfs_direct_req *dreq) | |
116 | { | |
117 | atomic_inc(&dreq->io_count); | |
118 | } | |
119 | ||
120 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
121 | { | |
122 | return atomic_dec_and_test(&dreq->io_count); | |
123 | } | |
124 | ||
0a00b77b WAA |
125 | static void |
126 | nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr) | |
127 | { | |
128 | int i; | |
129 | ssize_t count; | |
130 | ||
ed3743a6 WAA |
131 | WARN_ON_ONCE(dreq->count >= dreq->max_count); |
132 | ||
1ccbad9f PT |
133 | if (dreq->mirror_count == 1) { |
134 | dreq->mirrors[hdr->pgio_mirror_idx].count += hdr->good_bytes; | |
135 | dreq->count += hdr->good_bytes; | |
136 | } else { | |
137 | /* mirrored writes */ | |
138 | count = dreq->mirrors[hdr->pgio_mirror_idx].count; | |
139 | if (count + dreq->io_start < hdr->io_start + hdr->good_bytes) { | |
140 | count = hdr->io_start + hdr->good_bytes - dreq->io_start; | |
141 | dreq->mirrors[hdr->pgio_mirror_idx].count = count; | |
142 | } | |
143 | /* update the dreq->count by finding the minimum agreed count from all | |
144 | * mirrors */ | |
145 | count = dreq->mirrors[0].count; | |
0a00b77b | 146 | |
1ccbad9f PT |
147 | for (i = 1; i < dreq->mirror_count; i++) |
148 | count = min(count, dreq->mirrors[i].count); | |
0a00b77b | 149 | |
1ccbad9f | 150 | dreq->count = count; |
5fadeb47 | 151 | } |
0a00b77b WAA |
152 | } |
153 | ||
5002c586 WAA |
154 | /* |
155 | * nfs_direct_select_verf - select the right verifier | |
156 | * @dreq - direct request possibly spanning multiple servers | |
157 | * @ds_clp - nfs_client of data server or NULL if MDS / non-pnfs | |
6cccbb6f | 158 | * @commit_idx - commit bucket index for the DS |
5002c586 WAA |
159 | * |
160 | * returns the correct verifier to use given the role of the server | |
161 | */ | |
162 | static struct nfs_writeverf * | |
163 | nfs_direct_select_verf(struct nfs_direct_req *dreq, | |
164 | struct nfs_client *ds_clp, | |
6cccbb6f | 165 | int commit_idx) |
5002c586 WAA |
166 | { |
167 | struct nfs_writeverf *verfp = &dreq->verf; | |
168 | ||
169 | #ifdef CONFIG_NFS_V4_1 | |
834e465b KM |
170 | /* |
171 | * pNFS is in use, use the DS verf except commit_through_mds is set | |
172 | * for layout segment where nbuckets is zero. | |
173 | */ | |
174 | if (ds_clp && dreq->ds_cinfo.nbuckets > 0) { | |
6cccbb6f WAA |
175 | if (commit_idx >= 0 && commit_idx < dreq->ds_cinfo.nbuckets) |
176 | verfp = &dreq->ds_cinfo.buckets[commit_idx].direct_verf; | |
5002c586 WAA |
177 | else |
178 | WARN_ON_ONCE(1); | |
179 | } | |
180 | #endif | |
181 | return verfp; | |
182 | } | |
183 | ||
184 | ||
185 | /* | |
186 | * nfs_direct_set_hdr_verf - set the write/commit verifier | |
187 | * @dreq - direct request possibly spanning multiple servers | |
188 | * @hdr - pageio header to validate against previously seen verfs | |
189 | * | |
190 | * Set the server's (MDS or DS) "seen" verifier | |
191 | */ | |
192 | static void nfs_direct_set_hdr_verf(struct nfs_direct_req *dreq, | |
193 | struct nfs_pgio_header *hdr) | |
194 | { | |
195 | struct nfs_writeverf *verfp; | |
196 | ||
6cccbb6f | 197 | verfp = nfs_direct_select_verf(dreq, hdr->ds_clp, hdr->ds_commit_idx); |
5002c586 WAA |
198 | WARN_ON_ONCE(verfp->committed >= 0); |
199 | memcpy(verfp, &hdr->verf, sizeof(struct nfs_writeverf)); | |
200 | WARN_ON_ONCE(verfp->committed < 0); | |
201 | } | |
202 | ||
8fc3c386 TM |
203 | static int nfs_direct_cmp_verf(const struct nfs_writeverf *v1, |
204 | const struct nfs_writeverf *v2) | |
205 | { | |
206 | return nfs_write_verifier_cmp(&v1->verifier, &v2->verifier); | |
207 | } | |
208 | ||
5002c586 WAA |
209 | /* |
210 | * nfs_direct_cmp_hdr_verf - compare verifier for pgio header | |
211 | * @dreq - direct request possibly spanning multiple servers | |
212 | * @hdr - pageio header to validate against previously seen verf | |
213 | * | |
214 | * set the server's "seen" verf if not initialized. | |
215 | * returns result of comparison between @hdr->verf and the "seen" | |
216 | * verf of the server used by @hdr (DS or MDS) | |
217 | */ | |
218 | static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq, | |
219 | struct nfs_pgio_header *hdr) | |
220 | { | |
221 | struct nfs_writeverf *verfp; | |
222 | ||
6cccbb6f | 223 | verfp = nfs_direct_select_verf(dreq, hdr->ds_clp, hdr->ds_commit_idx); |
5002c586 WAA |
224 | if (verfp->committed < 0) { |
225 | nfs_direct_set_hdr_verf(dreq, hdr); | |
226 | return 0; | |
227 | } | |
8fc3c386 | 228 | return nfs_direct_cmp_verf(verfp, &hdr->verf); |
5002c586 WAA |
229 | } |
230 | ||
5002c586 WAA |
231 | /* |
232 | * nfs_direct_cmp_commit_data_verf - compare verifier for commit data | |
233 | * @dreq - direct request possibly spanning multiple servers | |
234 | * @data - commit data to validate against previously seen verf | |
235 | * | |
236 | * returns result of comparison between @data->verf and the verf of | |
237 | * the server used by @data (DS or MDS) | |
238 | */ | |
239 | static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq, | |
240 | struct nfs_commit_data *data) | |
241 | { | |
242 | struct nfs_writeverf *verfp; | |
243 | ||
244 | verfp = nfs_direct_select_verf(dreq, data->ds_clp, | |
245 | data->ds_commit_index); | |
80c76fe3 WAA |
246 | |
247 | /* verifier not set so always fail */ | |
248 | if (verfp->committed < 0) | |
249 | return 1; | |
250 | ||
8fc3c386 | 251 | return nfs_direct_cmp_verf(verfp, &data->verf); |
5002c586 | 252 | } |
5002c586 | 253 | |
1da177e4 | 254 | /** |
b8a32e2b | 255 | * nfs_direct_IO - NFS address space operation for direct I/O |
b8a32e2b | 256 | * @iocb: target I/O control block |
90090ae6 | 257 | * @iter: I/O buffer |
b8a32e2b CL |
258 | * |
259 | * The presence of this routine in the address space ops vector means | |
a564b8f0 MG |
260 | * the NFS client supports direct I/O. However, for most direct IO, we |
261 | * shunt off direct read and write requests before the VFS gets them, | |
262 | * so this method is only ever called for swap. | |
1da177e4 | 263 | */ |
c8b8e32d | 264 | ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
b8a32e2b | 265 | { |
ee8a1a8b PT |
266 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
267 | ||
268 | /* we only support swap file calling nfs_direct_IO */ | |
269 | if (!IS_SWAPFILE(inode)) | |
270 | return 0; | |
271 | ||
66ee59af | 272 | VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE); |
a564b8f0 | 273 | |
6f673763 | 274 | if (iov_iter_rw(iter) == READ) |
c8b8e32d | 275 | return nfs_file_direct_read(iocb, iter); |
65a4a1ca | 276 | return nfs_file_direct_write(iocb, iter); |
b8a32e2b CL |
277 | } |
278 | ||
749e146e | 279 | static void nfs_direct_release_pages(struct page **pages, unsigned int npages) |
9c93ab7d | 280 | { |
749e146e | 281 | unsigned int i; |
607f31e8 | 282 | for (i = 0; i < npages; i++) |
09cbfeaf | 283 | put_page(pages[i]); |
6b45d858 TM |
284 | } |
285 | ||
1763da12 FI |
286 | void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo, |
287 | struct nfs_direct_req *dreq) | |
288 | { | |
fe238e60 | 289 | cinfo->inode = dreq->inode; |
1763da12 FI |
290 | cinfo->mds = &dreq->mds_cinfo; |
291 | cinfo->ds = &dreq->ds_cinfo; | |
292 | cinfo->dreq = dreq; | |
293 | cinfo->completion_ops = &nfs_direct_commit_completion_ops; | |
294 | } | |
295 | ||
0a00b77b WAA |
296 | static inline void nfs_direct_setup_mirroring(struct nfs_direct_req *dreq, |
297 | struct nfs_pageio_descriptor *pgio, | |
298 | struct nfs_page *req) | |
299 | { | |
300 | int mirror_count = 1; | |
301 | ||
302 | if (pgio->pg_ops->pg_get_mirror_count) | |
303 | mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req); | |
304 | ||
305 | dreq->mirror_count = mirror_count; | |
306 | } | |
307 | ||
93619e59 | 308 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 309 | { |
93619e59 CL |
310 | struct nfs_direct_req *dreq; |
311 | ||
292f3eee | 312 | dreq = kmem_cache_zalloc(nfs_direct_cachep, GFP_KERNEL); |
93619e59 CL |
313 | if (!dreq) |
314 | return NULL; | |
315 | ||
316 | kref_init(&dreq->kref); | |
607f31e8 | 317 | kref_get(&dreq->kref); |
d72b7a6b | 318 | init_completion(&dreq->completion); |
1763da12 | 319 | INIT_LIST_HEAD(&dreq->mds_cinfo.list); |
5002c586 | 320 | dreq->verf.committed = NFS_INVALID_STABLE_HOW; /* not set yet */ |
1763da12 | 321 | INIT_WORK(&dreq->work, nfs_direct_write_schedule_work); |
0a00b77b | 322 | dreq->mirror_count = 1; |
15ce4a0c | 323 | spin_lock_init(&dreq->lock); |
93619e59 CL |
324 | |
325 | return dreq; | |
1da177e4 LT |
326 | } |
327 | ||
b4946ffb | 328 | static void nfs_direct_req_free(struct kref *kref) |
1da177e4 LT |
329 | { |
330 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a | 331 | |
8c393f9a | 332 | nfs_free_pnfs_ds_cinfo(&dreq->ds_cinfo); |
f11ac8db TM |
333 | if (dreq->l_ctx != NULL) |
334 | nfs_put_lock_context(dreq->l_ctx); | |
a8881f5a TM |
335 | if (dreq->ctx != NULL) |
336 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
337 | kmem_cache_free(nfs_direct_cachep, dreq); |
338 | } | |
339 | ||
b4946ffb TM |
340 | static void nfs_direct_req_release(struct nfs_direct_req *dreq) |
341 | { | |
342 | kref_put(&dreq->kref, nfs_direct_req_free); | |
343 | } | |
344 | ||
6296556f PT |
345 | ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq) |
346 | { | |
347 | return dreq->bytes_left; | |
348 | } | |
349 | EXPORT_SYMBOL_GPL(nfs_dreq_bytes_left); | |
350 | ||
bc0fb201 CL |
351 | /* |
352 | * Collects and returns the final error value/byte-count. | |
353 | */ | |
354 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
355 | { | |
15ce4a0c | 356 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
357 | |
358 | /* Async requests don't wait here */ | |
359 | if (dreq->iocb) | |
360 | goto out; | |
361 | ||
150030b7 | 362 | result = wait_for_completion_killable(&dreq->completion); |
bc0fb201 | 363 | |
d2a7de0b TM |
364 | if (!result) { |
365 | result = dreq->count; | |
366 | WARN_ON_ONCE(dreq->count < 0); | |
367 | } | |
bc0fb201 | 368 | if (!result) |
15ce4a0c | 369 | result = dreq->error; |
bc0fb201 CL |
370 | |
371 | out: | |
bc0fb201 CL |
372 | return (ssize_t) result; |
373 | } | |
374 | ||
63ab46ab | 375 | /* |
607f31e8 TM |
376 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
377 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab | 378 | */ |
f7b5c340 | 379 | static void nfs_direct_complete(struct nfs_direct_req *dreq) |
63ab46ab | 380 | { |
9811cd57 CH |
381 | struct inode *inode = dreq->inode; |
382 | ||
fe0f07d0 | 383 | inode_dio_end(inode); |
2a009ec9 CH |
384 | |
385 | if (dreq->iocb) { | |
15ce4a0c | 386 | long res = (long) dreq->error; |
d2a7de0b | 387 | if (dreq->count != 0) { |
15ce4a0c | 388 | res = (long) dreq->count; |
d2a7de0b TM |
389 | WARN_ON_ONCE(dreq->count < 0); |
390 | } | |
04b2fa9f | 391 | dreq->iocb->ki_complete(dreq->iocb, res, 0); |
d72b7a6b | 392 | } |
2a009ec9 | 393 | |
024de8f1 | 394 | complete(&dreq->completion); |
63ab46ab | 395 | |
b4946ffb | 396 | nfs_direct_req_release(dreq); |
63ab46ab CL |
397 | } |
398 | ||
584aa810 | 399 | static void nfs_direct_read_completion(struct nfs_pgio_header *hdr) |
fdd1e74c | 400 | { |
584aa810 FI |
401 | unsigned long bytes = 0; |
402 | struct nfs_direct_req *dreq = hdr->dreq; | |
fdd1e74c | 403 | |
584aa810 FI |
404 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) |
405 | goto out_put; | |
15ce4a0c CL |
406 | |
407 | spin_lock(&dreq->lock); | |
584aa810 FI |
408 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0)) |
409 | dreq->error = hdr->error; | |
410 | else | |
0a00b77b WAA |
411 | nfs_direct_good_bytes(dreq, hdr); |
412 | ||
584aa810 FI |
413 | spin_unlock(&dreq->lock); |
414 | ||
4bd8b010 TM |
415 | while (!list_empty(&hdr->pages)) { |
416 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
417 | struct page *page = req->wb_page; | |
418 | ||
ad3cba22 DK |
419 | if (!PageCompound(page) && bytes < hdr->good_bytes && |
420 | (dreq->flags == NFS_ODIRECT_SHOULD_DIRTY)) | |
be7e9858 | 421 | set_page_dirty(page); |
4bd8b010 TM |
422 | bytes += req->wb_bytes; |
423 | nfs_list_remove_request(req); | |
beeb5338 | 424 | nfs_release_request(req); |
d4a8f367 | 425 | } |
584aa810 | 426 | out_put: |
607f31e8 | 427 | if (put_dreq(dreq)) |
f7b5c340 | 428 | nfs_direct_complete(dreq); |
584aa810 | 429 | hdr->release(hdr); |
1da177e4 LT |
430 | } |
431 | ||
df3accb8 | 432 | static void nfs_read_sync_pgio_error(struct list_head *head, int error) |
cd841605 | 433 | { |
584aa810 | 434 | struct nfs_page *req; |
cd841605 | 435 | |
584aa810 FI |
436 | while (!list_empty(head)) { |
437 | req = nfs_list_entry(head->next); | |
438 | nfs_list_remove_request(req); | |
439 | nfs_release_request(req); | |
440 | } | |
cd841605 FI |
441 | } |
442 | ||
584aa810 FI |
443 | static void nfs_direct_pgio_init(struct nfs_pgio_header *hdr) |
444 | { | |
445 | get_dreq(hdr->dreq); | |
446 | } | |
447 | ||
448 | static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = { | |
3e9e0ca3 | 449 | .error_cleanup = nfs_read_sync_pgio_error, |
584aa810 FI |
450 | .init_hdr = nfs_direct_pgio_init, |
451 | .completion = nfs_direct_read_completion, | |
452 | }; | |
453 | ||
d4cc948b | 454 | /* |
607f31e8 TM |
455 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
456 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
457 | * bail and stop sending more reads. Read length accounting is | |
458 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
459 | * no requests have been sent, just return an error. | |
1da177e4 | 460 | */ |
1da177e4 | 461 | |
91f79c43 AV |
462 | static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, |
463 | struct iov_iter *iter, | |
464 | loff_t pos) | |
465 | { | |
466 | struct nfs_pageio_descriptor desc; | |
467 | struct inode *inode = dreq->inode; | |
468 | ssize_t result = -EINVAL; | |
469 | size_t requested_bytes = 0; | |
470 | size_t rsize = max_t(size_t, NFS_SERVER(inode)->rsize, PAGE_SIZE); | |
e9f7bee1 | 471 | |
16b90578 | 472 | nfs_pageio_init_read(&desc, dreq->inode, false, |
91f79c43 AV |
473 | &nfs_direct_read_completion_ops); |
474 | get_dreq(dreq); | |
475 | desc.pg_dreq = dreq; | |
fe0f07d0 | 476 | inode_dio_begin(inode); |
a564b8f0 | 477 | |
91f79c43 AV |
478 | while (iov_iter_count(iter)) { |
479 | struct page **pagevec; | |
480 | size_t bytes; | |
481 | size_t pgbase; | |
482 | unsigned npages, i; | |
607f31e8 | 483 | |
91f79c43 AV |
484 | result = iov_iter_get_pages_alloc(iter, &pagevec, |
485 | rsize, &pgbase); | |
486 | if (result < 0) | |
487 | break; | |
488 | ||
489 | bytes = result; | |
490 | iov_iter_advance(iter, bytes); | |
491 | npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE; | |
584aa810 FI |
492 | for (i = 0; i < npages; i++) { |
493 | struct nfs_page *req; | |
bf5fc402 | 494 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); |
584aa810 | 495 | /* XXX do we need to do the eof zeroing found in async_filler? */ |
28b1d3f5 | 496 | req = nfs_create_request(dreq->ctx, pagevec[i], |
584aa810 FI |
497 | pgbase, req_len); |
498 | if (IS_ERR(req)) { | |
584aa810 FI |
499 | result = PTR_ERR(req); |
500 | break; | |
501 | } | |
502 | req->wb_index = pos >> PAGE_SHIFT; | |
503 | req->wb_offset = pos & ~PAGE_MASK; | |
91f79c43 AV |
504 | if (!nfs_pageio_add_request(&desc, req)) { |
505 | result = desc.pg_error; | |
584aa810 | 506 | nfs_release_request(req); |
584aa810 FI |
507 | break; |
508 | } | |
509 | pgbase = 0; | |
510 | bytes -= req_len; | |
91f79c43 | 511 | requested_bytes += req_len; |
584aa810 | 512 | pos += req_len; |
35754bc0 | 513 | dreq->bytes_left -= req_len; |
584aa810 | 514 | } |
6d74743b | 515 | nfs_direct_release_pages(pagevec, npages); |
91f79c43 | 516 | kvfree(pagevec); |
19f73787 CL |
517 | if (result < 0) |
518 | break; | |
19f73787 CL |
519 | } |
520 | ||
584aa810 FI |
521 | nfs_pageio_complete(&desc); |
522 | ||
839f7ad6 CL |
523 | /* |
524 | * If no bytes were started, return the error, and let the | |
525 | * generic layer handle the completion. | |
526 | */ | |
527 | if (requested_bytes == 0) { | |
fe0f07d0 | 528 | inode_dio_end(inode); |
839f7ad6 CL |
529 | nfs_direct_req_release(dreq); |
530 | return result < 0 ? result : -EIO; | |
531 | } | |
532 | ||
19f73787 | 533 | if (put_dreq(dreq)) |
f7b5c340 | 534 | nfs_direct_complete(dreq); |
85128b2b | 535 | return requested_bytes; |
19f73787 CL |
536 | } |
537 | ||
14a3ec79 CH |
538 | /** |
539 | * nfs_file_direct_read - file direct read operation for NFS files | |
540 | * @iocb: target I/O control block | |
619d30b4 | 541 | * @iter: vector of user buffers into which to read data |
14a3ec79 CH |
542 | * |
543 | * We use this function for direct reads instead of calling | |
544 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
545 | * the request starts before the end of the file. For that check | |
546 | * to work, we must generate a GETATTR before each direct read, and | |
547 | * even then there is a window between the GETATTR and the subsequent | |
548 | * READ where the file size could change. Our preference is simply | |
549 | * to do all reads the application wants, and the server will take | |
550 | * care of managing the end of file boundary. | |
551 | * | |
552 | * This function also eliminates unnecessarily updating the file's | |
553 | * atime locally, as the NFS server sets the file's atime, and this | |
554 | * client must read the updated atime from the server back into its | |
555 | * cache. | |
556 | */ | |
c8b8e32d | 557 | ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 | 558 | { |
14a3ec79 CH |
559 | struct file *file = iocb->ki_filp; |
560 | struct address_space *mapping = file->f_mapping; | |
561 | struct inode *inode = mapping->host; | |
1da177e4 | 562 | struct nfs_direct_req *dreq; |
b3c54de6 | 563 | struct nfs_lock_context *l_ctx; |
85128b2b | 564 | ssize_t result = -EINVAL, requested; |
a6cbcd4a | 565 | size_t count = iov_iter_count(iter); |
14a3ec79 CH |
566 | nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); |
567 | ||
568 | dfprintk(FILE, "NFS: direct read(%pD2, %zd@%Ld)\n", | |
c8b8e32d | 569 | file, count, (long long) iocb->ki_pos); |
14a3ec79 CH |
570 | |
571 | result = 0; | |
572 | if (!count) | |
573 | goto out; | |
574 | ||
14a3ec79 CH |
575 | task_io_account_read(count); |
576 | ||
577 | result = -ENOMEM; | |
607f31e8 | 578 | dreq = nfs_direct_req_alloc(); |
f11ac8db | 579 | if (dreq == NULL) |
a5864c99 | 580 | goto out; |
1da177e4 | 581 | |
91d5b470 | 582 | dreq->inode = inode; |
ed3743a6 | 583 | dreq->bytes_left = dreq->max_count = count; |
c8b8e32d | 584 | dreq->io_start = iocb->ki_pos; |
cd3758e3 | 585 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
b3c54de6 TM |
586 | l_ctx = nfs_get_lock_context(dreq->ctx); |
587 | if (IS_ERR(l_ctx)) { | |
588 | result = PTR_ERR(l_ctx); | |
f11ac8db | 589 | goto out_release; |
b3c54de6 TM |
590 | } |
591 | dreq->l_ctx = l_ctx; | |
487b8372 CL |
592 | if (!is_sync_kiocb(iocb)) |
593 | dreq->iocb = iocb; | |
1da177e4 | 594 | |
ad3cba22 DK |
595 | if (iter_is_iovec(iter)) |
596 | dreq->flags = NFS_ODIRECT_SHOULD_DIRTY; | |
597 | ||
a5864c99 TM |
598 | nfs_start_io_direct(inode); |
599 | ||
619d30b4 | 600 | NFS_I(inode)->read_io += count; |
85128b2b | 601 | requested = nfs_direct_read_schedule_iovec(dreq, iter, iocb->ki_pos); |
d0b9875d | 602 | |
a5864c99 | 603 | nfs_end_io_direct(inode); |
d0b9875d | 604 | |
85128b2b | 605 | if (requested > 0) { |
607f31e8 | 606 | result = nfs_direct_wait(dreq); |
85128b2b AV |
607 | if (result > 0) { |
608 | requested -= result; | |
c8b8e32d | 609 | iocb->ki_pos += result; |
85128b2b AV |
610 | } |
611 | iov_iter_revert(iter, requested); | |
612 | } else { | |
613 | result = requested; | |
14a3ec79 | 614 | } |
d0b9875d | 615 | |
f11ac8db | 616 | out_release: |
b4946ffb | 617 | nfs_direct_req_release(dreq); |
f11ac8db | 618 | out: |
1da177e4 LT |
619 | return result; |
620 | } | |
621 | ||
085d1e33 TH |
622 | static void |
623 | nfs_direct_write_scan_commit_list(struct inode *inode, | |
624 | struct list_head *list, | |
625 | struct nfs_commit_info *cinfo) | |
626 | { | |
e824f99a | 627 | mutex_lock(&NFS_I(cinfo->inode)->commit_mutex); |
085d1e33 TH |
628 | #ifdef CONFIG_NFS_V4_1 |
629 | if (cinfo->ds != NULL && cinfo->ds->nwritten != 0) | |
630 | NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo); | |
631 | #endif | |
632 | nfs_scan_commit_list(&cinfo->mds->list, list, cinfo, 0); | |
e824f99a | 633 | mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex); |
085d1e33 TH |
634 | } |
635 | ||
fad61490 TM |
636 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) |
637 | { | |
1763da12 FI |
638 | struct nfs_pageio_descriptor desc; |
639 | struct nfs_page *req, *tmp; | |
640 | LIST_HEAD(reqs); | |
641 | struct nfs_commit_info cinfo; | |
642 | LIST_HEAD(failed); | |
0a00b77b | 643 | int i; |
1763da12 FI |
644 | |
645 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
085d1e33 | 646 | nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo); |
1da177e4 | 647 | |
fad61490 | 648 | dreq->count = 0; |
a5314a74 TM |
649 | dreq->verf.committed = NFS_INVALID_STABLE_HOW; |
650 | nfs_clear_pnfs_ds_commit_verifiers(&dreq->ds_cinfo); | |
0a00b77b WAA |
651 | for (i = 0; i < dreq->mirror_count; i++) |
652 | dreq->mirrors[i].count = 0; | |
607f31e8 TM |
653 | get_dreq(dreq); |
654 | ||
a20c93e3 | 655 | nfs_pageio_init_write(&desc, dreq->inode, FLUSH_STABLE, false, |
1763da12 FI |
656 | &nfs_direct_write_completion_ops); |
657 | desc.pg_dreq = dreq; | |
fedb595c | 658 | |
0a00b77b WAA |
659 | req = nfs_list_entry(reqs.next); |
660 | nfs_direct_setup_mirroring(dreq, &desc, req); | |
d600ad1f PT |
661 | if (desc.pg_error < 0) { |
662 | list_splice_init(&reqs, &failed); | |
663 | goto out_failed; | |
664 | } | |
0a00b77b | 665 | |
1763da12 | 666 | list_for_each_entry_safe(req, tmp, &reqs, wb_list) { |
33344e0f TM |
667 | /* Bump the transmission count */ |
668 | req->wb_nio++; | |
1763da12 | 669 | if (!nfs_pageio_add_request(&desc, req)) { |
078b5fd9 | 670 | nfs_list_move_request(req, &failed); |
fe238e60 | 671 | spin_lock(&cinfo.inode->i_lock); |
1763da12 | 672 | dreq->flags = 0; |
d600ad1f PT |
673 | if (desc.pg_error < 0) |
674 | dreq->error = desc.pg_error; | |
675 | else | |
676 | dreq->error = -EIO; | |
fe238e60 | 677 | spin_unlock(&cinfo.inode->i_lock); |
1763da12 | 678 | } |
5a695da2 | 679 | nfs_release_request(req); |
1763da12 FI |
680 | } |
681 | nfs_pageio_complete(&desc); | |
fad61490 | 682 | |
d600ad1f | 683 | out_failed: |
4035c248 TM |
684 | while (!list_empty(&failed)) { |
685 | req = nfs_list_entry(failed.next); | |
686 | nfs_list_remove_request(req); | |
1d1afcbc | 687 | nfs_unlock_and_release_request(req); |
4035c248 | 688 | } |
fad61490 | 689 | |
1763da12 | 690 | if (put_dreq(dreq)) |
4d3b55d3 | 691 | nfs_direct_write_complete(dreq); |
c9d8f89d TM |
692 | } |
693 | ||
1763da12 | 694 | static void nfs_direct_commit_complete(struct nfs_commit_data *data) |
c9d8f89d | 695 | { |
0b7c0153 | 696 | struct nfs_direct_req *dreq = data->dreq; |
1763da12 FI |
697 | struct nfs_commit_info cinfo; |
698 | struct nfs_page *req; | |
c9d8f89d TM |
699 | int status = data->task.tk_status; |
700 | ||
1763da12 | 701 | nfs_init_cinfo_from_dreq(&cinfo, dreq); |
fe4f844d | 702 | if (status < 0 || nfs_direct_cmp_commit_data_verf(dreq, data)) |
fad61490 | 703 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
1da177e4 | 704 | |
1763da12 FI |
705 | while (!list_empty(&data->pages)) { |
706 | req = nfs_list_entry(data->pages.next); | |
707 | nfs_list_remove_request(req); | |
708 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) { | |
33344e0f TM |
709 | /* |
710 | * Despite the reboot, the write was successful, | |
711 | * so reset wb_nio. | |
712 | */ | |
713 | req->wb_nio = 0; | |
1763da12 | 714 | /* Note the rewrite will go through mds */ |
b57ff130 | 715 | nfs_mark_request_commit(req, NULL, &cinfo, 0); |
906369e4 FI |
716 | } else |
717 | nfs_release_request(req); | |
1d1afcbc | 718 | nfs_unlock_and_release_request(req); |
1763da12 FI |
719 | } |
720 | ||
721 | if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) | |
4d3b55d3 | 722 | nfs_direct_write_complete(dreq); |
1da177e4 LT |
723 | } |
724 | ||
b20135d0 TM |
725 | static void nfs_direct_resched_write(struct nfs_commit_info *cinfo, |
726 | struct nfs_page *req) | |
1763da12 | 727 | { |
b20135d0 TM |
728 | struct nfs_direct_req *dreq = cinfo->dreq; |
729 | ||
730 | spin_lock(&dreq->lock); | |
731 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
732 | spin_unlock(&dreq->lock); | |
733 | nfs_mark_request_commit(req, NULL, cinfo, 0); | |
1763da12 FI |
734 | } |
735 | ||
736 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops = { | |
737 | .completion = nfs_direct_commit_complete, | |
b20135d0 | 738 | .resched_write = nfs_direct_resched_write, |
fad61490 TM |
739 | }; |
740 | ||
741 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 742 | { |
1763da12 FI |
743 | int res; |
744 | struct nfs_commit_info cinfo; | |
745 | LIST_HEAD(mds_list); | |
746 | ||
747 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
748 | nfs_scan_commit(dreq->inode, &mds_list, &cinfo); | |
749 | res = nfs_generic_commit_list(dreq->inode, &mds_list, 0, &cinfo); | |
750 | if (res < 0) /* res == -ENOMEM */ | |
751 | nfs_direct_write_reschedule(dreq); | |
fad61490 | 752 | } |
1da177e4 | 753 | |
1763da12 | 754 | static void nfs_direct_write_schedule_work(struct work_struct *work) |
fad61490 | 755 | { |
1763da12 | 756 | struct nfs_direct_req *dreq = container_of(work, struct nfs_direct_req, work); |
fad61490 | 757 | int flags = dreq->flags; |
1da177e4 | 758 | |
fad61490 TM |
759 | dreq->flags = 0; |
760 | switch (flags) { | |
761 | case NFS_ODIRECT_DO_COMMIT: | |
762 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 763 | break; |
fad61490 TM |
764 | case NFS_ODIRECT_RESCHED_WRITES: |
765 | nfs_direct_write_reschedule(dreq); | |
766 | break; | |
767 | default: | |
f7b5c340 TM |
768 | nfs_zap_mapping(dreq->inode, dreq->inode->i_mapping); |
769 | nfs_direct_complete(dreq); | |
fad61490 TM |
770 | } |
771 | } | |
1da177e4 | 772 | |
4d3b55d3 | 773 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq) |
fad61490 | 774 | { |
46483c2e | 775 | queue_work(nfsiod_workqueue, &dreq->work); /* Calls nfs_direct_write_schedule_work */ |
fad61490 | 776 | } |
1763da12 | 777 | |
1763da12 FI |
778 | static void nfs_direct_write_completion(struct nfs_pgio_header *hdr) |
779 | { | |
780 | struct nfs_direct_req *dreq = hdr->dreq; | |
781 | struct nfs_commit_info cinfo; | |
c65e6254 | 782 | bool request_commit = false; |
1763da12 FI |
783 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); |
784 | ||
785 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) | |
786 | goto out_put; | |
787 | ||
788 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
789 | ||
790 | spin_lock(&dreq->lock); | |
791 | ||
1b8d97b0 | 792 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) |
1763da12 | 793 | dreq->error = hdr->error; |
c65e6254 | 794 | if (dreq->error == 0) { |
0a00b77b | 795 | nfs_direct_good_bytes(dreq, hdr); |
c65e6254 | 796 | if (nfs_write_need_commit(hdr)) { |
1763da12 | 797 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) |
c65e6254 | 798 | request_commit = true; |
1763da12 | 799 | else if (dreq->flags == 0) { |
5002c586 | 800 | nfs_direct_set_hdr_verf(dreq, hdr); |
c65e6254 | 801 | request_commit = true; |
1763da12 FI |
802 | dreq->flags = NFS_ODIRECT_DO_COMMIT; |
803 | } else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) { | |
c65e6254 WAA |
804 | request_commit = true; |
805 | if (nfs_direct_set_or_cmp_hdr_verf(dreq, hdr)) | |
5002c586 WAA |
806 | dreq->flags = |
807 | NFS_ODIRECT_RESCHED_WRITES; | |
1763da12 FI |
808 | } |
809 | } | |
810 | } | |
811 | spin_unlock(&dreq->lock); | |
812 | ||
813 | while (!list_empty(&hdr->pages)) { | |
2bfc6e56 | 814 | |
1763da12 FI |
815 | req = nfs_list_entry(hdr->pages.next); |
816 | nfs_list_remove_request(req); | |
c65e6254 | 817 | if (request_commit) { |
04277086 | 818 | kref_get(&req->wb_kref); |
b57ff130 WAA |
819 | nfs_mark_request_commit(req, hdr->lseg, &cinfo, |
820 | hdr->ds_commit_idx); | |
1763da12 | 821 | } |
1d1afcbc | 822 | nfs_unlock_and_release_request(req); |
1763da12 FI |
823 | } |
824 | ||
825 | out_put: | |
826 | if (put_dreq(dreq)) | |
4d3b55d3 | 827 | nfs_direct_write_complete(dreq); |
1763da12 FI |
828 | hdr->release(hdr); |
829 | } | |
830 | ||
df3accb8 | 831 | static void nfs_write_sync_pgio_error(struct list_head *head, int error) |
3e9e0ca3 TM |
832 | { |
833 | struct nfs_page *req; | |
834 | ||
835 | while (!list_empty(head)) { | |
836 | req = nfs_list_entry(head->next); | |
837 | nfs_list_remove_request(req); | |
1d1afcbc | 838 | nfs_unlock_and_release_request(req); |
3e9e0ca3 TM |
839 | } |
840 | } | |
841 | ||
dc602dd7 TM |
842 | static void nfs_direct_write_reschedule_io(struct nfs_pgio_header *hdr) |
843 | { | |
844 | struct nfs_direct_req *dreq = hdr->dreq; | |
845 | ||
846 | spin_lock(&dreq->lock); | |
847 | if (dreq->error == 0) { | |
848 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
849 | /* fake unstable write to let common nfs resend pages */ | |
850 | hdr->verf.committed = NFS_UNSTABLE; | |
851 | hdr->good_bytes = hdr->args.count; | |
852 | } | |
853 | spin_unlock(&dreq->lock); | |
854 | } | |
855 | ||
1763da12 | 856 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = { |
3e9e0ca3 | 857 | .error_cleanup = nfs_write_sync_pgio_error, |
1763da12 FI |
858 | .init_hdr = nfs_direct_pgio_init, |
859 | .completion = nfs_direct_write_completion, | |
dc602dd7 | 860 | .reschedule_io = nfs_direct_write_reschedule_io, |
1763da12 FI |
861 | }; |
862 | ||
91f79c43 AV |
863 | |
864 | /* | |
865 | * NB: Return the value of the first error return code. Subsequent | |
866 | * errors after the first one are ignored. | |
867 | */ | |
868 | /* | |
869 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE | |
870 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
871 | * bail and stop sending more writes. Write length accounting is | |
872 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
873 | * no requests have been sent, just return an error. | |
874 | */ | |
19f73787 | 875 | static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, |
619d30b4 | 876 | struct iov_iter *iter, |
91f79c43 | 877 | loff_t pos) |
19f73787 | 878 | { |
1763da12 | 879 | struct nfs_pageio_descriptor desc; |
1d59d61f | 880 | struct inode *inode = dreq->inode; |
19f73787 CL |
881 | ssize_t result = 0; |
882 | size_t requested_bytes = 0; | |
91f79c43 | 883 | size_t wsize = max_t(size_t, NFS_SERVER(inode)->wsize, PAGE_SIZE); |
19f73787 | 884 | |
a20c93e3 | 885 | nfs_pageio_init_write(&desc, inode, FLUSH_COND_STABLE, false, |
1763da12 FI |
886 | &nfs_direct_write_completion_ops); |
887 | desc.pg_dreq = dreq; | |
19f73787 | 888 | get_dreq(dreq); |
fe0f07d0 | 889 | inode_dio_begin(inode); |
19f73787 | 890 | |
91f79c43 AV |
891 | NFS_I(inode)->write_io += iov_iter_count(iter); |
892 | while (iov_iter_count(iter)) { | |
893 | struct page **pagevec; | |
894 | size_t bytes; | |
895 | size_t pgbase; | |
896 | unsigned npages, i; | |
897 | ||
898 | result = iov_iter_get_pages_alloc(iter, &pagevec, | |
899 | wsize, &pgbase); | |
19f73787 CL |
900 | if (result < 0) |
901 | break; | |
91f79c43 AV |
902 | |
903 | bytes = result; | |
904 | iov_iter_advance(iter, bytes); | |
905 | npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE; | |
906 | for (i = 0; i < npages; i++) { | |
907 | struct nfs_page *req; | |
908 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); | |
909 | ||
28b1d3f5 | 910 | req = nfs_create_request(dreq->ctx, pagevec[i], |
91f79c43 AV |
911 | pgbase, req_len); |
912 | if (IS_ERR(req)) { | |
913 | result = PTR_ERR(req); | |
914 | break; | |
915 | } | |
0a00b77b WAA |
916 | |
917 | nfs_direct_setup_mirroring(dreq, &desc, req); | |
d600ad1f PT |
918 | if (desc.pg_error < 0) { |
919 | nfs_free_request(req); | |
920 | result = desc.pg_error; | |
921 | break; | |
922 | } | |
0a00b77b | 923 | |
91f79c43 AV |
924 | nfs_lock_request(req); |
925 | req->wb_index = pos >> PAGE_SHIFT; | |
926 | req->wb_offset = pos & ~PAGE_MASK; | |
927 | if (!nfs_pageio_add_request(&desc, req)) { | |
928 | result = desc.pg_error; | |
929 | nfs_unlock_and_release_request(req); | |
930 | break; | |
931 | } | |
932 | pgbase = 0; | |
933 | bytes -= req_len; | |
934 | requested_bytes += req_len; | |
935 | pos += req_len; | |
936 | dreq->bytes_left -= req_len; | |
937 | } | |
938 | nfs_direct_release_pages(pagevec, npages); | |
939 | kvfree(pagevec); | |
940 | if (result < 0) | |
19f73787 | 941 | break; |
19f73787 | 942 | } |
1763da12 | 943 | nfs_pageio_complete(&desc); |
19f73787 | 944 | |
839f7ad6 CL |
945 | /* |
946 | * If no bytes were started, return the error, and let the | |
947 | * generic layer handle the completion. | |
948 | */ | |
949 | if (requested_bytes == 0) { | |
fe0f07d0 | 950 | inode_dio_end(inode); |
839f7ad6 CL |
951 | nfs_direct_req_release(dreq); |
952 | return result < 0 ? result : -EIO; | |
953 | } | |
954 | ||
19f73787 | 955 | if (put_dreq(dreq)) |
4d3b55d3 | 956 | nfs_direct_write_complete(dreq); |
85128b2b | 957 | return requested_bytes; |
19f73787 CL |
958 | } |
959 | ||
1da177e4 LT |
960 | /** |
961 | * nfs_file_direct_write - file direct write operation for NFS files | |
962 | * @iocb: target I/O control block | |
619d30b4 | 963 | * @iter: vector of user buffers from which to write data |
1da177e4 LT |
964 | * |
965 | * We use this function for direct writes instead of calling | |
966 | * generic_file_aio_write() in order to avoid taking the inode | |
967 | * semaphore and updating the i_size. The NFS server will set | |
968 | * the new i_size and this client must read the updated size | |
969 | * back into its cache. We let the server do generic write | |
970 | * parameter checking and report problems. | |
971 | * | |
1da177e4 LT |
972 | * We eliminate local atime updates, see direct read above. |
973 | * | |
974 | * We avoid unnecessary page cache invalidations for normal cached | |
975 | * readers of this file. | |
976 | * | |
977 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
978 | * is no atomic O_APPEND write facility in the NFS protocol. | |
979 | */ | |
65a4a1ca | 980 | ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 | 981 | { |
85128b2b | 982 | ssize_t result = -EINVAL, requested; |
89698b24 | 983 | size_t count; |
1da177e4 | 984 | struct file *file = iocb->ki_filp; |
1da177e4 | 985 | struct address_space *mapping = file->f_mapping; |
22cd1bf1 CH |
986 | struct inode *inode = mapping->host; |
987 | struct nfs_direct_req *dreq; | |
988 | struct nfs_lock_context *l_ctx; | |
65a4a1ca | 989 | loff_t pos, end; |
c216fd70 | 990 | |
6de1472f | 991 | dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n", |
3309dd04 | 992 | file, iov_iter_count(iter), (long long) iocb->ki_pos); |
027445c3 | 993 | |
89698b24 TM |
994 | result = generic_write_checks(iocb, iter); |
995 | if (result <= 0) | |
996 | return result; | |
997 | count = result; | |
998 | nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); | |
3309dd04 AV |
999 | |
1000 | pos = iocb->ki_pos; | |
09cbfeaf | 1001 | end = (pos + iov_iter_count(iter) - 1) >> PAGE_SHIFT; |
ce1a8e67 | 1002 | |
89698b24 | 1003 | task_io_account_write(count); |
7ec10f26 | 1004 | |
22cd1bf1 CH |
1005 | result = -ENOMEM; |
1006 | dreq = nfs_direct_req_alloc(); | |
1007 | if (!dreq) | |
a5864c99 | 1008 | goto out; |
9eafa8cc | 1009 | |
22cd1bf1 | 1010 | dreq->inode = inode; |
89698b24 | 1011 | dreq->bytes_left = dreq->max_count = count; |
5fadeb47 | 1012 | dreq->io_start = pos; |
22cd1bf1 CH |
1013 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
1014 | l_ctx = nfs_get_lock_context(dreq->ctx); | |
1015 | if (IS_ERR(l_ctx)) { | |
1016 | result = PTR_ERR(l_ctx); | |
1017 | goto out_release; | |
1018 | } | |
1019 | dreq->l_ctx = l_ctx; | |
1020 | if (!is_sync_kiocb(iocb)) | |
1021 | dreq->iocb = iocb; | |
1022 | ||
a5864c99 TM |
1023 | nfs_start_io_direct(inode); |
1024 | ||
85128b2b | 1025 | requested = nfs_direct_write_schedule_iovec(dreq, iter, pos); |
a9ab5e84 CH |
1026 | |
1027 | if (mapping->nrpages) { | |
1028 | invalidate_inode_pages2_range(mapping, | |
09cbfeaf | 1029 | pos >> PAGE_SHIFT, end); |
a9ab5e84 CH |
1030 | } |
1031 | ||
a5864c99 | 1032 | nfs_end_io_direct(inode); |
a9ab5e84 | 1033 | |
85128b2b | 1034 | if (requested > 0) { |
22cd1bf1 CH |
1035 | result = nfs_direct_wait(dreq); |
1036 | if (result > 0) { | |
85128b2b | 1037 | requested -= result; |
22cd1bf1 | 1038 | iocb->ki_pos = pos + result; |
e2592217 CH |
1039 | /* XXX: should check the generic_write_sync retval */ |
1040 | generic_write_sync(iocb, result); | |
22cd1bf1 | 1041 | } |
85128b2b AV |
1042 | iov_iter_revert(iter, requested); |
1043 | } else { | |
1044 | result = requested; | |
1763da12 | 1045 | } |
22cd1bf1 CH |
1046 | out_release: |
1047 | nfs_direct_req_release(dreq); | |
a5864c99 | 1048 | out: |
22cd1bf1 | 1049 | return result; |
1da177e4 LT |
1050 | } |
1051 | ||
88467055 CL |
1052 | /** |
1053 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
1054 | * | |
1055 | */ | |
f7b422b1 | 1056 | int __init nfs_init_directcache(void) |
1da177e4 LT |
1057 | { |
1058 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
1059 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
1060 | 0, (SLAB_RECLAIM_ACCOUNT| |
1061 | SLAB_MEM_SPREAD), | |
20c2df83 | 1062 | NULL); |
1da177e4 LT |
1063 | if (nfs_direct_cachep == NULL) |
1064 | return -ENOMEM; | |
1065 | ||
1066 | return 0; | |
1067 | } | |
1068 | ||
88467055 | 1069 | /** |
f7b422b1 | 1070 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
1071 | * |
1072 | */ | |
266bee88 | 1073 | void nfs_destroy_directcache(void) |
1da177e4 | 1074 | { |
1a1d92c1 | 1075 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 1076 | } |