Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/nfs/direct.c | |
3 | * | |
4 | * Copyright (C) 2003 by Chuck Lever <cel@netapp.com> | |
5 | * | |
6 | * High-performance uncached I/O for the Linux NFS client | |
7 | * | |
8 | * There are important applications whose performance or correctness | |
9 | * depends on uncached access to file data. Database clusters | |
88467055 | 10 | * (multiple copies of the same instance running on separate hosts) |
1da177e4 | 11 | * implement their own cache coherency protocol that subsumes file |
88467055 CL |
12 | * system cache protocols. Applications that process datasets |
13 | * considerably larger than the client's memory do not always benefit | |
14 | * from a local cache. A streaming video server, for instance, has no | |
1da177e4 LT |
15 | * need to cache the contents of a file. |
16 | * | |
17 | * When an application requests uncached I/O, all read and write requests | |
18 | * are made directly to the server; data stored or fetched via these | |
19 | * requests is not cached in the Linux page cache. The client does not | |
20 | * correct unaligned requests from applications. All requested bytes are | |
21 | * held on permanent storage before a direct write system call returns to | |
22 | * an application. | |
23 | * | |
24 | * Solaris implements an uncached I/O facility called directio() that | |
25 | * is used for backups and sequential I/O to very large files. Solaris | |
26 | * also supports uncaching whole NFS partitions with "-o forcedirectio," | |
27 | * an undocumented mount option. | |
28 | * | |
29 | * Designed by Jeff Kimmel, Chuck Lever, and Trond Myklebust, with | |
30 | * help from Andrew Morton. | |
31 | * | |
32 | * 18 Dec 2001 Initial implementation for 2.4 --cel | |
33 | * 08 Jul 2002 Version for 2.4.19, with bug fixes --trondmy | |
34 | * 08 Jun 2003 Port to 2.5 APIs --cel | |
35 | * 31 Mar 2004 Handle direct I/O without VFS support --cel | |
36 | * 15 Sep 2004 Parallel async reads --cel | |
88467055 | 37 | * 04 May 2005 support O_DIRECT with aio --cel |
1da177e4 LT |
38 | * |
39 | */ | |
40 | ||
1da177e4 LT |
41 | #include <linux/errno.h> |
42 | #include <linux/sched.h> | |
43 | #include <linux/kernel.h> | |
1da177e4 LT |
44 | #include <linux/file.h> |
45 | #include <linux/pagemap.h> | |
46 | #include <linux/kref.h> | |
5a0e3ad6 | 47 | #include <linux/slab.h> |
7ec10f26 | 48 | #include <linux/task_io_accounting_ops.h> |
6296556f | 49 | #include <linux/module.h> |
1da177e4 LT |
50 | |
51 | #include <linux/nfs_fs.h> | |
52 | #include <linux/nfs_page.h> | |
53 | #include <linux/sunrpc/clnt.h> | |
54 | ||
1da177e4 | 55 | #include <asm/uaccess.h> |
60063497 | 56 | #include <linux/atomic.h> |
1da177e4 | 57 | |
8d5658c9 | 58 | #include "internal.h" |
91d5b470 | 59 | #include "iostat.h" |
1763da12 | 60 | #include "pnfs.h" |
91d5b470 | 61 | |
1da177e4 | 62 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 | 63 | |
e18b890b | 64 | static struct kmem_cache *nfs_direct_cachep; |
1da177e4 LT |
65 | |
66 | /* | |
67 | * This represents a set of asynchronous requests that we're waiting on | |
68 | */ | |
0a00b77b WAA |
69 | struct nfs_direct_mirror { |
70 | ssize_t count; | |
71 | }; | |
72 | ||
1da177e4 LT |
73 | struct nfs_direct_req { |
74 | struct kref kref; /* release manager */ | |
15ce4a0c CL |
75 | |
76 | /* I/O parameters */ | |
a8881f5a | 77 | struct nfs_open_context *ctx; /* file open context info */ |
f11ac8db | 78 | struct nfs_lock_context *l_ctx; /* Lock context info */ |
99514f8f | 79 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 80 | struct inode * inode; /* target file of i/o */ |
15ce4a0c CL |
81 | |
82 | /* completion state */ | |
607f31e8 | 83 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 84 | spinlock_t lock; /* protect completion state */ |
0a00b77b WAA |
85 | |
86 | struct nfs_direct_mirror mirrors[NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX]; | |
87 | int mirror_count; | |
88 | ||
15ce4a0c | 89 | ssize_t count, /* bytes actually processed */ |
35754bc0 | 90 | bytes_left, /* bytes left to be sent */ |
5fadeb47 | 91 | io_start, /* start of IO */ |
1da177e4 | 92 | error; /* any reported error */ |
d72b7a6b | 93 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
94 | |
95 | /* commit state */ | |
1763da12 FI |
96 | struct nfs_mds_commit_info mds_cinfo; /* Storage for cinfo */ |
97 | struct pnfs_ds_commit_info ds_cinfo; /* Storage for cinfo */ | |
98 | struct work_struct work; | |
fad61490 TM |
99 | int flags; |
100 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ | |
101 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
102 | struct nfs_writeverf verf; /* unstable write verifier */ | |
1da177e4 LT |
103 | }; |
104 | ||
1763da12 FI |
105 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops; |
106 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops; | |
fad61490 | 107 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); |
1763da12 | 108 | static void nfs_direct_write_schedule_work(struct work_struct *work); |
607f31e8 TM |
109 | |
110 | static inline void get_dreq(struct nfs_direct_req *dreq) | |
111 | { | |
112 | atomic_inc(&dreq->io_count); | |
113 | } | |
114 | ||
115 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
116 | { | |
117 | return atomic_dec_and_test(&dreq->io_count); | |
118 | } | |
119 | ||
012fa16d PT |
120 | void nfs_direct_set_resched_writes(struct nfs_direct_req *dreq) |
121 | { | |
122 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
123 | } | |
124 | EXPORT_SYMBOL_GPL(nfs_direct_set_resched_writes); | |
125 | ||
0a00b77b WAA |
126 | static void |
127 | nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr) | |
128 | { | |
129 | int i; | |
130 | ssize_t count; | |
131 | ||
132 | WARN_ON_ONCE(hdr->pgio_mirror_idx >= dreq->mirror_count); | |
133 | ||
5fadeb47 PT |
134 | count = dreq->mirrors[hdr->pgio_mirror_idx].count; |
135 | if (count + dreq->io_start < hdr->io_start + hdr->good_bytes) { | |
136 | count = hdr->io_start + hdr->good_bytes - dreq->io_start; | |
137 | dreq->mirrors[hdr->pgio_mirror_idx].count = count; | |
138 | } | |
0a00b77b WAA |
139 | |
140 | /* update the dreq->count by finding the minimum agreed count from all | |
141 | * mirrors */ | |
142 | count = dreq->mirrors[0].count; | |
143 | ||
144 | for (i = 1; i < dreq->mirror_count; i++) | |
145 | count = min(count, dreq->mirrors[i].count); | |
146 | ||
147 | dreq->count = count; | |
148 | } | |
149 | ||
5002c586 WAA |
150 | /* |
151 | * nfs_direct_select_verf - select the right verifier | |
152 | * @dreq - direct request possibly spanning multiple servers | |
153 | * @ds_clp - nfs_client of data server or NULL if MDS / non-pnfs | |
6cccbb6f | 154 | * @commit_idx - commit bucket index for the DS |
5002c586 WAA |
155 | * |
156 | * returns the correct verifier to use given the role of the server | |
157 | */ | |
158 | static struct nfs_writeverf * | |
159 | nfs_direct_select_verf(struct nfs_direct_req *dreq, | |
160 | struct nfs_client *ds_clp, | |
6cccbb6f | 161 | int commit_idx) |
5002c586 WAA |
162 | { |
163 | struct nfs_writeverf *verfp = &dreq->verf; | |
164 | ||
165 | #ifdef CONFIG_NFS_V4_1 | |
166 | if (ds_clp) { | |
167 | /* pNFS is in use, use the DS verf */ | |
6cccbb6f WAA |
168 | if (commit_idx >= 0 && commit_idx < dreq->ds_cinfo.nbuckets) |
169 | verfp = &dreq->ds_cinfo.buckets[commit_idx].direct_verf; | |
5002c586 WAA |
170 | else |
171 | WARN_ON_ONCE(1); | |
172 | } | |
173 | #endif | |
174 | return verfp; | |
175 | } | |
176 | ||
177 | ||
178 | /* | |
179 | * nfs_direct_set_hdr_verf - set the write/commit verifier | |
180 | * @dreq - direct request possibly spanning multiple servers | |
181 | * @hdr - pageio header to validate against previously seen verfs | |
182 | * | |
183 | * Set the server's (MDS or DS) "seen" verifier | |
184 | */ | |
185 | static void nfs_direct_set_hdr_verf(struct nfs_direct_req *dreq, | |
186 | struct nfs_pgio_header *hdr) | |
187 | { | |
188 | struct nfs_writeverf *verfp; | |
189 | ||
6cccbb6f | 190 | verfp = nfs_direct_select_verf(dreq, hdr->ds_clp, hdr->ds_commit_idx); |
5002c586 WAA |
191 | WARN_ON_ONCE(verfp->committed >= 0); |
192 | memcpy(verfp, &hdr->verf, sizeof(struct nfs_writeverf)); | |
193 | WARN_ON_ONCE(verfp->committed < 0); | |
194 | } | |
195 | ||
196 | /* | |
197 | * nfs_direct_cmp_hdr_verf - compare verifier for pgio header | |
198 | * @dreq - direct request possibly spanning multiple servers | |
199 | * @hdr - pageio header to validate against previously seen verf | |
200 | * | |
201 | * set the server's "seen" verf if not initialized. | |
202 | * returns result of comparison between @hdr->verf and the "seen" | |
203 | * verf of the server used by @hdr (DS or MDS) | |
204 | */ | |
205 | static int nfs_direct_set_or_cmp_hdr_verf(struct nfs_direct_req *dreq, | |
206 | struct nfs_pgio_header *hdr) | |
207 | { | |
208 | struct nfs_writeverf *verfp; | |
209 | ||
6cccbb6f | 210 | verfp = nfs_direct_select_verf(dreq, hdr->ds_clp, hdr->ds_commit_idx); |
5002c586 WAA |
211 | if (verfp->committed < 0) { |
212 | nfs_direct_set_hdr_verf(dreq, hdr); | |
213 | return 0; | |
214 | } | |
215 | return memcmp(verfp, &hdr->verf, sizeof(struct nfs_writeverf)); | |
216 | } | |
217 | ||
5002c586 WAA |
218 | /* |
219 | * nfs_direct_cmp_commit_data_verf - compare verifier for commit data | |
220 | * @dreq - direct request possibly spanning multiple servers | |
221 | * @data - commit data to validate against previously seen verf | |
222 | * | |
223 | * returns result of comparison between @data->verf and the verf of | |
224 | * the server used by @data (DS or MDS) | |
225 | */ | |
226 | static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq, | |
227 | struct nfs_commit_data *data) | |
228 | { | |
229 | struct nfs_writeverf *verfp; | |
230 | ||
231 | verfp = nfs_direct_select_verf(dreq, data->ds_clp, | |
232 | data->ds_commit_index); | |
80c76fe3 WAA |
233 | |
234 | /* verifier not set so always fail */ | |
235 | if (verfp->committed < 0) | |
236 | return 1; | |
237 | ||
5002c586 WAA |
238 | return memcmp(verfp, &data->verf, sizeof(struct nfs_writeverf)); |
239 | } | |
5002c586 | 240 | |
1da177e4 | 241 | /** |
b8a32e2b | 242 | * nfs_direct_IO - NFS address space operation for direct I/O |
b8a32e2b CL |
243 | * @iocb: target I/O control block |
244 | * @iov: array of vectors that define I/O buffer | |
245 | * @pos: offset in file to begin the operation | |
246 | * @nr_segs: size of iovec array | |
247 | * | |
248 | * The presence of this routine in the address space ops vector means | |
a564b8f0 MG |
249 | * the NFS client supports direct I/O. However, for most direct IO, we |
250 | * shunt off direct read and write requests before the VFS gets them, | |
251 | * so this method is only ever called for swap. | |
1da177e4 | 252 | */ |
22c6186e | 253 | ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t pos) |
b8a32e2b | 254 | { |
ee8a1a8b PT |
255 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
256 | ||
257 | /* we only support swap file calling nfs_direct_IO */ | |
258 | if (!IS_SWAPFILE(inode)) | |
259 | return 0; | |
260 | ||
a564b8f0 | 261 | #ifndef CONFIG_NFS_SWAP |
6de1472f | 262 | dprintk("NFS: nfs_direct_IO (%pD) off/no(%Ld/%lu) EINVAL\n", |
d8d3d94b | 263 | iocb->ki_filp, (long long) pos, iter->nr_segs); |
b8a32e2b CL |
264 | |
265 | return -EINVAL; | |
a564b8f0 | 266 | #else |
66ee59af | 267 | VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE); |
a564b8f0 | 268 | |
6f673763 | 269 | if (iov_iter_rw(iter) == READ) |
e19a8a0a MP |
270 | return nfs_file_direct_read(iocb, iter, pos); |
271 | return nfs_file_direct_write(iocb, iter, pos); | |
a564b8f0 | 272 | #endif /* CONFIG_NFS_SWAP */ |
b8a32e2b CL |
273 | } |
274 | ||
749e146e | 275 | static void nfs_direct_release_pages(struct page **pages, unsigned int npages) |
9c93ab7d | 276 | { |
749e146e | 277 | unsigned int i; |
607f31e8 TM |
278 | for (i = 0; i < npages; i++) |
279 | page_cache_release(pages[i]); | |
6b45d858 TM |
280 | } |
281 | ||
1763da12 FI |
282 | void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo, |
283 | struct nfs_direct_req *dreq) | |
284 | { | |
f4086a3d | 285 | cinfo->lock = &dreq->inode->i_lock; |
1763da12 FI |
286 | cinfo->mds = &dreq->mds_cinfo; |
287 | cinfo->ds = &dreq->ds_cinfo; | |
288 | cinfo->dreq = dreq; | |
289 | cinfo->completion_ops = &nfs_direct_commit_completion_ops; | |
290 | } | |
291 | ||
0a00b77b WAA |
292 | static inline void nfs_direct_setup_mirroring(struct nfs_direct_req *dreq, |
293 | struct nfs_pageio_descriptor *pgio, | |
294 | struct nfs_page *req) | |
295 | { | |
296 | int mirror_count = 1; | |
297 | ||
298 | if (pgio->pg_ops->pg_get_mirror_count) | |
299 | mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req); | |
300 | ||
301 | dreq->mirror_count = mirror_count; | |
302 | } | |
303 | ||
93619e59 | 304 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 305 | { |
93619e59 CL |
306 | struct nfs_direct_req *dreq; |
307 | ||
292f3eee | 308 | dreq = kmem_cache_zalloc(nfs_direct_cachep, GFP_KERNEL); |
93619e59 CL |
309 | if (!dreq) |
310 | return NULL; | |
311 | ||
312 | kref_init(&dreq->kref); | |
607f31e8 | 313 | kref_get(&dreq->kref); |
d72b7a6b | 314 | init_completion(&dreq->completion); |
1763da12 | 315 | INIT_LIST_HEAD(&dreq->mds_cinfo.list); |
5002c586 | 316 | dreq->verf.committed = NFS_INVALID_STABLE_HOW; /* not set yet */ |
1763da12 | 317 | INIT_WORK(&dreq->work, nfs_direct_write_schedule_work); |
0a00b77b | 318 | dreq->mirror_count = 1; |
15ce4a0c | 319 | spin_lock_init(&dreq->lock); |
93619e59 CL |
320 | |
321 | return dreq; | |
1da177e4 LT |
322 | } |
323 | ||
b4946ffb | 324 | static void nfs_direct_req_free(struct kref *kref) |
1da177e4 LT |
325 | { |
326 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a | 327 | |
8c393f9a | 328 | nfs_free_pnfs_ds_cinfo(&dreq->ds_cinfo); |
f11ac8db TM |
329 | if (dreq->l_ctx != NULL) |
330 | nfs_put_lock_context(dreq->l_ctx); | |
a8881f5a TM |
331 | if (dreq->ctx != NULL) |
332 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
333 | kmem_cache_free(nfs_direct_cachep, dreq); |
334 | } | |
335 | ||
b4946ffb TM |
336 | static void nfs_direct_req_release(struct nfs_direct_req *dreq) |
337 | { | |
338 | kref_put(&dreq->kref, nfs_direct_req_free); | |
339 | } | |
340 | ||
6296556f PT |
341 | ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq) |
342 | { | |
343 | return dreq->bytes_left; | |
344 | } | |
345 | EXPORT_SYMBOL_GPL(nfs_dreq_bytes_left); | |
346 | ||
bc0fb201 CL |
347 | /* |
348 | * Collects and returns the final error value/byte-count. | |
349 | */ | |
350 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
351 | { | |
15ce4a0c | 352 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
353 | |
354 | /* Async requests don't wait here */ | |
355 | if (dreq->iocb) | |
356 | goto out; | |
357 | ||
150030b7 | 358 | result = wait_for_completion_killable(&dreq->completion); |
bc0fb201 CL |
359 | |
360 | if (!result) | |
15ce4a0c | 361 | result = dreq->error; |
bc0fb201 | 362 | if (!result) |
15ce4a0c | 363 | result = dreq->count; |
bc0fb201 CL |
364 | |
365 | out: | |
bc0fb201 CL |
366 | return (ssize_t) result; |
367 | } | |
368 | ||
63ab46ab | 369 | /* |
607f31e8 TM |
370 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
371 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab | 372 | */ |
9811cd57 | 373 | static void nfs_direct_complete(struct nfs_direct_req *dreq, bool write) |
63ab46ab | 374 | { |
9811cd57 CH |
375 | struct inode *inode = dreq->inode; |
376 | ||
2a009ec9 | 377 | if (dreq->iocb && write) { |
9811cd57 | 378 | loff_t pos = dreq->iocb->ki_pos + dreq->count; |
2a009ec9 CH |
379 | |
380 | spin_lock(&inode->i_lock); | |
381 | if (i_size_read(inode) < pos) | |
382 | i_size_write(inode, pos); | |
383 | spin_unlock(&inode->i_lock); | |
384 | } | |
385 | ||
1f90ee27 | 386 | if (write) |
2a009ec9 | 387 | nfs_zap_mapping(inode, inode->i_mapping); |
1f90ee27 CH |
388 | |
389 | inode_dio_done(inode); | |
2a009ec9 CH |
390 | |
391 | if (dreq->iocb) { | |
15ce4a0c | 392 | long res = (long) dreq->error; |
63ab46ab | 393 | if (!res) |
15ce4a0c | 394 | res = (long) dreq->count; |
04b2fa9f | 395 | dreq->iocb->ki_complete(dreq->iocb, res, 0); |
d72b7a6b | 396 | } |
2a009ec9 | 397 | |
d72b7a6b | 398 | complete_all(&dreq->completion); |
63ab46ab | 399 | |
b4946ffb | 400 | nfs_direct_req_release(dreq); |
63ab46ab CL |
401 | } |
402 | ||
1385b811 | 403 | static void nfs_direct_readpage_release(struct nfs_page *req) |
1da177e4 | 404 | { |
1e8968c5 | 405 | dprintk("NFS: direct read done (%s/%llu %d@%lld)\n", |
584aa810 | 406 | req->wb_context->dentry->d_inode->i_sb->s_id, |
1e8968c5 | 407 | (unsigned long long)NFS_FILEID(req->wb_context->dentry->d_inode), |
584aa810 FI |
408 | req->wb_bytes, |
409 | (long long)req_offset(req)); | |
410 | nfs_release_request(req); | |
fdd1e74c TM |
411 | } |
412 | ||
584aa810 | 413 | static void nfs_direct_read_completion(struct nfs_pgio_header *hdr) |
fdd1e74c | 414 | { |
584aa810 FI |
415 | unsigned long bytes = 0; |
416 | struct nfs_direct_req *dreq = hdr->dreq; | |
fdd1e74c | 417 | |
584aa810 FI |
418 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) |
419 | goto out_put; | |
15ce4a0c CL |
420 | |
421 | spin_lock(&dreq->lock); | |
584aa810 FI |
422 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0)) |
423 | dreq->error = hdr->error; | |
424 | else | |
0a00b77b WAA |
425 | nfs_direct_good_bytes(dreq, hdr); |
426 | ||
584aa810 FI |
427 | spin_unlock(&dreq->lock); |
428 | ||
4bd8b010 TM |
429 | while (!list_empty(&hdr->pages)) { |
430 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
431 | struct page *page = req->wb_page; | |
432 | ||
be7e9858 JL |
433 | if (!PageCompound(page) && bytes < hdr->good_bytes) |
434 | set_page_dirty(page); | |
4bd8b010 TM |
435 | bytes += req->wb_bytes; |
436 | nfs_list_remove_request(req); | |
437 | nfs_direct_readpage_release(req); | |
d4a8f367 | 438 | } |
584aa810 | 439 | out_put: |
607f31e8 | 440 | if (put_dreq(dreq)) |
9811cd57 | 441 | nfs_direct_complete(dreq, false); |
584aa810 | 442 | hdr->release(hdr); |
1da177e4 LT |
443 | } |
444 | ||
3e9e0ca3 | 445 | static void nfs_read_sync_pgio_error(struct list_head *head) |
cd841605 | 446 | { |
584aa810 | 447 | struct nfs_page *req; |
cd841605 | 448 | |
584aa810 FI |
449 | while (!list_empty(head)) { |
450 | req = nfs_list_entry(head->next); | |
451 | nfs_list_remove_request(req); | |
452 | nfs_release_request(req); | |
453 | } | |
cd841605 FI |
454 | } |
455 | ||
584aa810 FI |
456 | static void nfs_direct_pgio_init(struct nfs_pgio_header *hdr) |
457 | { | |
458 | get_dreq(hdr->dreq); | |
459 | } | |
460 | ||
461 | static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = { | |
3e9e0ca3 | 462 | .error_cleanup = nfs_read_sync_pgio_error, |
584aa810 FI |
463 | .init_hdr = nfs_direct_pgio_init, |
464 | .completion = nfs_direct_read_completion, | |
465 | }; | |
466 | ||
d4cc948b | 467 | /* |
607f31e8 TM |
468 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
469 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
470 | * bail and stop sending more reads. Read length accounting is | |
471 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
472 | * no requests have been sent, just return an error. | |
1da177e4 | 473 | */ |
1da177e4 | 474 | |
91f79c43 AV |
475 | static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, |
476 | struct iov_iter *iter, | |
477 | loff_t pos) | |
478 | { | |
479 | struct nfs_pageio_descriptor desc; | |
480 | struct inode *inode = dreq->inode; | |
481 | ssize_t result = -EINVAL; | |
482 | size_t requested_bytes = 0; | |
483 | size_t rsize = max_t(size_t, NFS_SERVER(inode)->rsize, PAGE_SIZE); | |
e9f7bee1 | 484 | |
16b90578 | 485 | nfs_pageio_init_read(&desc, dreq->inode, false, |
91f79c43 AV |
486 | &nfs_direct_read_completion_ops); |
487 | get_dreq(dreq); | |
488 | desc.pg_dreq = dreq; | |
489 | atomic_inc(&inode->i_dio_count); | |
a564b8f0 | 490 | |
91f79c43 AV |
491 | while (iov_iter_count(iter)) { |
492 | struct page **pagevec; | |
493 | size_t bytes; | |
494 | size_t pgbase; | |
495 | unsigned npages, i; | |
607f31e8 | 496 | |
91f79c43 AV |
497 | result = iov_iter_get_pages_alloc(iter, &pagevec, |
498 | rsize, &pgbase); | |
499 | if (result < 0) | |
500 | break; | |
501 | ||
502 | bytes = result; | |
503 | iov_iter_advance(iter, bytes); | |
504 | npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE; | |
584aa810 FI |
505 | for (i = 0; i < npages; i++) { |
506 | struct nfs_page *req; | |
bf5fc402 | 507 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); |
584aa810 | 508 | /* XXX do we need to do the eof zeroing found in async_filler? */ |
2bfc6e56 | 509 | req = nfs_create_request(dreq->ctx, pagevec[i], NULL, |
584aa810 FI |
510 | pgbase, req_len); |
511 | if (IS_ERR(req)) { | |
584aa810 FI |
512 | result = PTR_ERR(req); |
513 | break; | |
514 | } | |
515 | req->wb_index = pos >> PAGE_SHIFT; | |
516 | req->wb_offset = pos & ~PAGE_MASK; | |
91f79c43 AV |
517 | if (!nfs_pageio_add_request(&desc, req)) { |
518 | result = desc.pg_error; | |
584aa810 | 519 | nfs_release_request(req); |
584aa810 FI |
520 | break; |
521 | } | |
522 | pgbase = 0; | |
523 | bytes -= req_len; | |
91f79c43 | 524 | requested_bytes += req_len; |
584aa810 | 525 | pos += req_len; |
35754bc0 | 526 | dreq->bytes_left -= req_len; |
584aa810 | 527 | } |
6d74743b | 528 | nfs_direct_release_pages(pagevec, npages); |
91f79c43 | 529 | kvfree(pagevec); |
19f73787 CL |
530 | if (result < 0) |
531 | break; | |
19f73787 CL |
532 | } |
533 | ||
584aa810 FI |
534 | nfs_pageio_complete(&desc); |
535 | ||
839f7ad6 CL |
536 | /* |
537 | * If no bytes were started, return the error, and let the | |
538 | * generic layer handle the completion. | |
539 | */ | |
540 | if (requested_bytes == 0) { | |
1f90ee27 | 541 | inode_dio_done(inode); |
839f7ad6 CL |
542 | nfs_direct_req_release(dreq); |
543 | return result < 0 ? result : -EIO; | |
544 | } | |
545 | ||
19f73787 | 546 | if (put_dreq(dreq)) |
9811cd57 | 547 | nfs_direct_complete(dreq, false); |
839f7ad6 | 548 | return 0; |
19f73787 CL |
549 | } |
550 | ||
14a3ec79 CH |
551 | /** |
552 | * nfs_file_direct_read - file direct read operation for NFS files | |
553 | * @iocb: target I/O control block | |
619d30b4 | 554 | * @iter: vector of user buffers into which to read data |
14a3ec79 CH |
555 | * @pos: byte offset in file where reading starts |
556 | * | |
557 | * We use this function for direct reads instead of calling | |
558 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
559 | * the request starts before the end of the file. For that check | |
560 | * to work, we must generate a GETATTR before each direct read, and | |
561 | * even then there is a window between the GETATTR and the subsequent | |
562 | * READ where the file size could change. Our preference is simply | |
563 | * to do all reads the application wants, and the server will take | |
564 | * care of managing the end of file boundary. | |
565 | * | |
566 | * This function also eliminates unnecessarily updating the file's | |
567 | * atime locally, as the NFS server sets the file's atime, and this | |
568 | * client must read the updated atime from the server back into its | |
569 | * cache. | |
570 | */ | |
619d30b4 | 571 | ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter, |
e19a8a0a | 572 | loff_t pos) |
1da177e4 | 573 | { |
14a3ec79 CH |
574 | struct file *file = iocb->ki_filp; |
575 | struct address_space *mapping = file->f_mapping; | |
576 | struct inode *inode = mapping->host; | |
1da177e4 | 577 | struct nfs_direct_req *dreq; |
b3c54de6 | 578 | struct nfs_lock_context *l_ctx; |
14a3ec79 | 579 | ssize_t result = -EINVAL; |
a6cbcd4a | 580 | size_t count = iov_iter_count(iter); |
14a3ec79 CH |
581 | nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); |
582 | ||
583 | dfprintk(FILE, "NFS: direct read(%pD2, %zd@%Ld)\n", | |
584 | file, count, (long long) pos); | |
585 | ||
586 | result = 0; | |
587 | if (!count) | |
588 | goto out; | |
589 | ||
d0b9875d | 590 | mutex_lock(&inode->i_mutex); |
14a3ec79 CH |
591 | result = nfs_sync_mapping(mapping); |
592 | if (result) | |
d0b9875d | 593 | goto out_unlock; |
1da177e4 | 594 | |
14a3ec79 CH |
595 | task_io_account_read(count); |
596 | ||
597 | result = -ENOMEM; | |
607f31e8 | 598 | dreq = nfs_direct_req_alloc(); |
f11ac8db | 599 | if (dreq == NULL) |
d0b9875d | 600 | goto out_unlock; |
1da177e4 | 601 | |
91d5b470 | 602 | dreq->inode = inode; |
619d30b4 | 603 | dreq->bytes_left = count; |
5fadeb47 | 604 | dreq->io_start = pos; |
cd3758e3 | 605 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
b3c54de6 TM |
606 | l_ctx = nfs_get_lock_context(dreq->ctx); |
607 | if (IS_ERR(l_ctx)) { | |
608 | result = PTR_ERR(l_ctx); | |
f11ac8db | 609 | goto out_release; |
b3c54de6 TM |
610 | } |
611 | dreq->l_ctx = l_ctx; | |
487b8372 CL |
612 | if (!is_sync_kiocb(iocb)) |
613 | dreq->iocb = iocb; | |
1da177e4 | 614 | |
619d30b4 | 615 | NFS_I(inode)->read_io += count; |
91f79c43 | 616 | result = nfs_direct_read_schedule_iovec(dreq, iter, pos); |
d0b9875d CH |
617 | |
618 | mutex_unlock(&inode->i_mutex); | |
619 | ||
14a3ec79 | 620 | if (!result) { |
607f31e8 | 621 | result = nfs_direct_wait(dreq); |
14a3ec79 CH |
622 | if (result > 0) |
623 | iocb->ki_pos = pos + result; | |
624 | } | |
d0b9875d CH |
625 | |
626 | nfs_direct_req_release(dreq); | |
627 | return result; | |
628 | ||
f11ac8db | 629 | out_release: |
b4946ffb | 630 | nfs_direct_req_release(dreq); |
d0b9875d CH |
631 | out_unlock: |
632 | mutex_unlock(&inode->i_mutex); | |
f11ac8db | 633 | out: |
1da177e4 LT |
634 | return result; |
635 | } | |
636 | ||
085d1e33 TH |
637 | static void |
638 | nfs_direct_write_scan_commit_list(struct inode *inode, | |
639 | struct list_head *list, | |
640 | struct nfs_commit_info *cinfo) | |
641 | { | |
642 | spin_lock(cinfo->lock); | |
643 | #ifdef CONFIG_NFS_V4_1 | |
644 | if (cinfo->ds != NULL && cinfo->ds->nwritten != 0) | |
645 | NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo); | |
646 | #endif | |
647 | nfs_scan_commit_list(&cinfo->mds->list, list, cinfo, 0); | |
648 | spin_unlock(cinfo->lock); | |
649 | } | |
650 | ||
fad61490 TM |
651 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) |
652 | { | |
1763da12 FI |
653 | struct nfs_pageio_descriptor desc; |
654 | struct nfs_page *req, *tmp; | |
655 | LIST_HEAD(reqs); | |
656 | struct nfs_commit_info cinfo; | |
657 | LIST_HEAD(failed); | |
0a00b77b | 658 | int i; |
1763da12 FI |
659 | |
660 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
085d1e33 | 661 | nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo); |
1da177e4 | 662 | |
fad61490 | 663 | dreq->count = 0; |
0a00b77b WAA |
664 | for (i = 0; i < dreq->mirror_count; i++) |
665 | dreq->mirrors[i].count = 0; | |
607f31e8 TM |
666 | get_dreq(dreq); |
667 | ||
a20c93e3 | 668 | nfs_pageio_init_write(&desc, dreq->inode, FLUSH_STABLE, false, |
1763da12 FI |
669 | &nfs_direct_write_completion_ops); |
670 | desc.pg_dreq = dreq; | |
fedb595c | 671 | |
0a00b77b WAA |
672 | req = nfs_list_entry(reqs.next); |
673 | nfs_direct_setup_mirroring(dreq, &desc, req); | |
674 | ||
1763da12 FI |
675 | list_for_each_entry_safe(req, tmp, &reqs, wb_list) { |
676 | if (!nfs_pageio_add_request(&desc, req)) { | |
4035c248 | 677 | nfs_list_remove_request(req); |
1763da12 FI |
678 | nfs_list_add_request(req, &failed); |
679 | spin_lock(cinfo.lock); | |
680 | dreq->flags = 0; | |
681 | dreq->error = -EIO; | |
682 | spin_unlock(cinfo.lock); | |
683 | } | |
5a695da2 | 684 | nfs_release_request(req); |
1763da12 FI |
685 | } |
686 | nfs_pageio_complete(&desc); | |
fad61490 | 687 | |
4035c248 TM |
688 | while (!list_empty(&failed)) { |
689 | req = nfs_list_entry(failed.next); | |
690 | nfs_list_remove_request(req); | |
1d1afcbc | 691 | nfs_unlock_and_release_request(req); |
4035c248 | 692 | } |
fad61490 | 693 | |
1763da12 FI |
694 | if (put_dreq(dreq)) |
695 | nfs_direct_write_complete(dreq, dreq->inode); | |
c9d8f89d TM |
696 | } |
697 | ||
1763da12 | 698 | static void nfs_direct_commit_complete(struct nfs_commit_data *data) |
c9d8f89d | 699 | { |
0b7c0153 | 700 | struct nfs_direct_req *dreq = data->dreq; |
1763da12 FI |
701 | struct nfs_commit_info cinfo; |
702 | struct nfs_page *req; | |
c9d8f89d TM |
703 | int status = data->task.tk_status; |
704 | ||
1763da12 | 705 | nfs_init_cinfo_from_dreq(&cinfo, dreq); |
c9d8f89d | 706 | if (status < 0) { |
60fa3f76 | 707 | dprintk("NFS: %5u commit failed with error %d.\n", |
1763da12 | 708 | data->task.tk_pid, status); |
fad61490 | 709 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
5002c586 | 710 | } else if (nfs_direct_cmp_commit_data_verf(dreq, data)) { |
c9d8f89d | 711 | dprintk("NFS: %5u commit verify failed\n", data->task.tk_pid); |
fad61490 | 712 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
1da177e4 LT |
713 | } |
714 | ||
c9d8f89d | 715 | dprintk("NFS: %5u commit returned %d\n", data->task.tk_pid, status); |
1763da12 FI |
716 | while (!list_empty(&data->pages)) { |
717 | req = nfs_list_entry(data->pages.next); | |
718 | nfs_list_remove_request(req); | |
719 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) { | |
720 | /* Note the rewrite will go through mds */ | |
b57ff130 | 721 | nfs_mark_request_commit(req, NULL, &cinfo, 0); |
906369e4 FI |
722 | } else |
723 | nfs_release_request(req); | |
1d1afcbc | 724 | nfs_unlock_and_release_request(req); |
1763da12 FI |
725 | } |
726 | ||
727 | if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) | |
728 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
729 | } |
730 | ||
1763da12 FI |
731 | static void nfs_direct_error_cleanup(struct nfs_inode *nfsi) |
732 | { | |
733 | /* There is no lock to clear */ | |
734 | } | |
735 | ||
736 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops = { | |
737 | .completion = nfs_direct_commit_complete, | |
738 | .error_cleanup = nfs_direct_error_cleanup, | |
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: | |
9811cd57 | 768 | nfs_direct_complete(dreq, true); |
fad61490 TM |
769 | } |
770 | } | |
1da177e4 | 771 | |
1763da12 | 772 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
fad61490 | 773 | { |
1763da12 | 774 | schedule_work(&dreq->work); /* Calls nfs_direct_write_schedule_work */ |
fad61490 | 775 | } |
1763da12 | 776 | |
1763da12 FI |
777 | static void nfs_direct_write_completion(struct nfs_pgio_header *hdr) |
778 | { | |
779 | struct nfs_direct_req *dreq = hdr->dreq; | |
780 | struct nfs_commit_info cinfo; | |
c65e6254 | 781 | bool request_commit = false; |
1763da12 FI |
782 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); |
783 | ||
784 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) | |
785 | goto out_put; | |
786 | ||
787 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
788 | ||
789 | spin_lock(&dreq->lock); | |
790 | ||
791 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
792 | dreq->flags = 0; | |
793 | dreq->error = hdr->error; | |
794 | } | |
c65e6254 | 795 | if (dreq->error == 0) { |
0a00b77b | 796 | nfs_direct_good_bytes(dreq, hdr); |
c65e6254 | 797 | if (nfs_write_need_commit(hdr)) { |
1763da12 | 798 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) |
c65e6254 | 799 | request_commit = true; |
1763da12 | 800 | else if (dreq->flags == 0) { |
5002c586 | 801 | nfs_direct_set_hdr_verf(dreq, hdr); |
c65e6254 | 802 | request_commit = true; |
1763da12 FI |
803 | dreq->flags = NFS_ODIRECT_DO_COMMIT; |
804 | } else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) { | |
c65e6254 WAA |
805 | request_commit = true; |
806 | if (nfs_direct_set_or_cmp_hdr_verf(dreq, hdr)) | |
5002c586 WAA |
807 | dreq->flags = |
808 | NFS_ODIRECT_RESCHED_WRITES; | |
1763da12 FI |
809 | } |
810 | } | |
811 | } | |
812 | spin_unlock(&dreq->lock); | |
813 | ||
814 | while (!list_empty(&hdr->pages)) { | |
2bfc6e56 | 815 | |
1763da12 FI |
816 | req = nfs_list_entry(hdr->pages.next); |
817 | nfs_list_remove_request(req); | |
c65e6254 | 818 | if (request_commit) { |
04277086 | 819 | kref_get(&req->wb_kref); |
b57ff130 WAA |
820 | nfs_mark_request_commit(req, hdr->lseg, &cinfo, |
821 | hdr->ds_commit_idx); | |
1763da12 | 822 | } |
1d1afcbc | 823 | nfs_unlock_and_release_request(req); |
1763da12 FI |
824 | } |
825 | ||
826 | out_put: | |
827 | if (put_dreq(dreq)) | |
828 | nfs_direct_write_complete(dreq, hdr->inode); | |
829 | hdr->release(hdr); | |
830 | } | |
831 | ||
3e9e0ca3 TM |
832 | static void nfs_write_sync_pgio_error(struct list_head *head) |
833 | { | |
834 | struct nfs_page *req; | |
835 | ||
836 | while (!list_empty(head)) { | |
837 | req = nfs_list_entry(head->next); | |
838 | nfs_list_remove_request(req); | |
1d1afcbc | 839 | nfs_unlock_and_release_request(req); |
3e9e0ca3 TM |
840 | } |
841 | } | |
842 | ||
1763da12 | 843 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = { |
3e9e0ca3 | 844 | .error_cleanup = nfs_write_sync_pgio_error, |
1763da12 FI |
845 | .init_hdr = nfs_direct_pgio_init, |
846 | .completion = nfs_direct_write_completion, | |
847 | }; | |
848 | ||
91f79c43 AV |
849 | |
850 | /* | |
851 | * NB: Return the value of the first error return code. Subsequent | |
852 | * errors after the first one are ignored. | |
853 | */ | |
854 | /* | |
855 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE | |
856 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
857 | * bail and stop sending more writes. Write length accounting is | |
858 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
859 | * no requests have been sent, just return an error. | |
860 | */ | |
19f73787 | 861 | static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, |
619d30b4 | 862 | struct iov_iter *iter, |
91f79c43 | 863 | loff_t pos) |
19f73787 | 864 | { |
1763da12 | 865 | struct nfs_pageio_descriptor desc; |
1d59d61f | 866 | struct inode *inode = dreq->inode; |
19f73787 CL |
867 | ssize_t result = 0; |
868 | size_t requested_bytes = 0; | |
91f79c43 | 869 | size_t wsize = max_t(size_t, NFS_SERVER(inode)->wsize, PAGE_SIZE); |
19f73787 | 870 | |
a20c93e3 | 871 | nfs_pageio_init_write(&desc, inode, FLUSH_COND_STABLE, false, |
1763da12 FI |
872 | &nfs_direct_write_completion_ops); |
873 | desc.pg_dreq = dreq; | |
19f73787 | 874 | get_dreq(dreq); |
1d59d61f | 875 | atomic_inc(&inode->i_dio_count); |
19f73787 | 876 | |
91f79c43 AV |
877 | NFS_I(inode)->write_io += iov_iter_count(iter); |
878 | while (iov_iter_count(iter)) { | |
879 | struct page **pagevec; | |
880 | size_t bytes; | |
881 | size_t pgbase; | |
882 | unsigned npages, i; | |
883 | ||
884 | result = iov_iter_get_pages_alloc(iter, &pagevec, | |
885 | wsize, &pgbase); | |
19f73787 CL |
886 | if (result < 0) |
887 | break; | |
91f79c43 AV |
888 | |
889 | bytes = result; | |
890 | iov_iter_advance(iter, bytes); | |
891 | npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE; | |
892 | for (i = 0; i < npages; i++) { | |
893 | struct nfs_page *req; | |
894 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); | |
895 | ||
16b90578 | 896 | req = nfs_create_request(dreq->ctx, pagevec[i], NULL, |
91f79c43 AV |
897 | pgbase, req_len); |
898 | if (IS_ERR(req)) { | |
899 | result = PTR_ERR(req); | |
900 | break; | |
901 | } | |
0a00b77b WAA |
902 | |
903 | nfs_direct_setup_mirroring(dreq, &desc, req); | |
904 | ||
91f79c43 AV |
905 | nfs_lock_request(req); |
906 | req->wb_index = pos >> PAGE_SHIFT; | |
907 | req->wb_offset = pos & ~PAGE_MASK; | |
908 | if (!nfs_pageio_add_request(&desc, req)) { | |
909 | result = desc.pg_error; | |
910 | nfs_unlock_and_release_request(req); | |
911 | break; | |
912 | } | |
913 | pgbase = 0; | |
914 | bytes -= req_len; | |
915 | requested_bytes += req_len; | |
916 | pos += req_len; | |
917 | dreq->bytes_left -= req_len; | |
918 | } | |
919 | nfs_direct_release_pages(pagevec, npages); | |
920 | kvfree(pagevec); | |
921 | if (result < 0) | |
19f73787 | 922 | break; |
19f73787 | 923 | } |
1763da12 | 924 | nfs_pageio_complete(&desc); |
19f73787 | 925 | |
839f7ad6 CL |
926 | /* |
927 | * If no bytes were started, return the error, and let the | |
928 | * generic layer handle the completion. | |
929 | */ | |
930 | if (requested_bytes == 0) { | |
1d59d61f | 931 | inode_dio_done(inode); |
839f7ad6 CL |
932 | nfs_direct_req_release(dreq); |
933 | return result < 0 ? result : -EIO; | |
934 | } | |
935 | ||
19f73787 CL |
936 | if (put_dreq(dreq)) |
937 | nfs_direct_write_complete(dreq, dreq->inode); | |
839f7ad6 | 938 | return 0; |
19f73787 CL |
939 | } |
940 | ||
1da177e4 LT |
941 | /** |
942 | * nfs_file_direct_write - file direct write operation for NFS files | |
943 | * @iocb: target I/O control block | |
619d30b4 | 944 | * @iter: vector of user buffers from which to write data |
88467055 | 945 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
946 | * |
947 | * We use this function for direct writes instead of calling | |
948 | * generic_file_aio_write() in order to avoid taking the inode | |
949 | * semaphore and updating the i_size. The NFS server will set | |
950 | * the new i_size and this client must read the updated size | |
951 | * back into its cache. We let the server do generic write | |
952 | * parameter checking and report problems. | |
953 | * | |
1da177e4 LT |
954 | * We eliminate local atime updates, see direct read above. |
955 | * | |
956 | * We avoid unnecessary page cache invalidations for normal cached | |
957 | * readers of this file. | |
958 | * | |
959 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
960 | * is no atomic O_APPEND write facility in the NFS protocol. | |
961 | */ | |
619d30b4 | 962 | ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter, |
e19a8a0a | 963 | loff_t pos) |
1da177e4 | 964 | { |
22cd1bf1 | 965 | ssize_t result = -EINVAL; |
1da177e4 | 966 | struct file *file = iocb->ki_filp; |
1da177e4 | 967 | struct address_space *mapping = file->f_mapping; |
22cd1bf1 CH |
968 | struct inode *inode = mapping->host; |
969 | struct nfs_direct_req *dreq; | |
970 | struct nfs_lock_context *l_ctx; | |
a9ab5e84 | 971 | loff_t end; |
a6cbcd4a | 972 | size_t count = iov_iter_count(iter); |
a9ab5e84 CH |
973 | end = (pos + count - 1) >> PAGE_CACHE_SHIFT; |
974 | ||
c216fd70 CL |
975 | nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); |
976 | ||
6de1472f AV |
977 | dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n", |
978 | file, count, (long long) pos); | |
027445c3 | 979 | |
22cd1bf1 CH |
980 | result = generic_write_checks(file, &pos, &count, 0); |
981 | if (result) | |
1da177e4 | 982 | goto out; |
ce1a8e67 | 983 | |
22cd1bf1 | 984 | result = -EINVAL; |
ce1a8e67 | 985 | if ((ssize_t) count < 0) |
1da177e4 | 986 | goto out; |
22cd1bf1 | 987 | result = 0; |
1da177e4 LT |
988 | if (!count) |
989 | goto out; | |
ce1a8e67 | 990 | |
a9ab5e84 CH |
991 | mutex_lock(&inode->i_mutex); |
992 | ||
22cd1bf1 CH |
993 | result = nfs_sync_mapping(mapping); |
994 | if (result) | |
a9ab5e84 CH |
995 | goto out_unlock; |
996 | ||
997 | if (mapping->nrpages) { | |
998 | result = invalidate_inode_pages2_range(mapping, | |
999 | pos >> PAGE_CACHE_SHIFT, end); | |
1000 | if (result) | |
1001 | goto out_unlock; | |
1002 | } | |
1da177e4 | 1003 | |
7ec10f26 KK |
1004 | task_io_account_write(count); |
1005 | ||
22cd1bf1 CH |
1006 | result = -ENOMEM; |
1007 | dreq = nfs_direct_req_alloc(); | |
1008 | if (!dreq) | |
a9ab5e84 | 1009 | goto out_unlock; |
9eafa8cc | 1010 | |
22cd1bf1 CH |
1011 | dreq->inode = inode; |
1012 | dreq->bytes_left = count; | |
5fadeb47 | 1013 | dreq->io_start = pos; |
22cd1bf1 CH |
1014 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
1015 | l_ctx = nfs_get_lock_context(dreq->ctx); | |
1016 | if (IS_ERR(l_ctx)) { | |
1017 | result = PTR_ERR(l_ctx); | |
1018 | goto out_release; | |
1019 | } | |
1020 | dreq->l_ctx = l_ctx; | |
1021 | if (!is_sync_kiocb(iocb)) | |
1022 | dreq->iocb = iocb; | |
1023 | ||
91f79c43 | 1024 | result = nfs_direct_write_schedule_iovec(dreq, iter, pos); |
a9ab5e84 CH |
1025 | |
1026 | if (mapping->nrpages) { | |
1027 | invalidate_inode_pages2_range(mapping, | |
1028 | pos >> PAGE_CACHE_SHIFT, end); | |
1029 | } | |
1030 | ||
1031 | mutex_unlock(&inode->i_mutex); | |
1032 | ||
22cd1bf1 CH |
1033 | if (!result) { |
1034 | result = nfs_direct_wait(dreq); | |
1035 | if (result > 0) { | |
1036 | struct inode *inode = mapping->host; | |
1037 | ||
1038 | iocb->ki_pos = pos + result; | |
1039 | spin_lock(&inode->i_lock); | |
1040 | if (i_size_read(inode) < iocb->ki_pos) | |
1041 | i_size_write(inode, iocb->ki_pos); | |
1042 | spin_unlock(&inode->i_lock); | |
1043 | } | |
1763da12 | 1044 | } |
a9ab5e84 CH |
1045 | nfs_direct_req_release(dreq); |
1046 | return result; | |
1047 | ||
22cd1bf1 CH |
1048 | out_release: |
1049 | nfs_direct_req_release(dreq); | |
a9ab5e84 CH |
1050 | out_unlock: |
1051 | mutex_unlock(&inode->i_mutex); | |
1da177e4 | 1052 | out: |
22cd1bf1 | 1053 | return result; |
1da177e4 LT |
1054 | } |
1055 | ||
88467055 CL |
1056 | /** |
1057 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
1058 | * | |
1059 | */ | |
f7b422b1 | 1060 | int __init nfs_init_directcache(void) |
1da177e4 LT |
1061 | { |
1062 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
1063 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
1064 | 0, (SLAB_RECLAIM_ACCOUNT| |
1065 | SLAB_MEM_SPREAD), | |
20c2df83 | 1066 | NULL); |
1da177e4 LT |
1067 | if (nfs_direct_cachep == NULL) |
1068 | return -ENOMEM; | |
1069 | ||
1070 | return 0; | |
1071 | } | |
1072 | ||
88467055 | 1073 | /** |
f7b422b1 | 1074 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
1075 | * |
1076 | */ | |
266bee88 | 1077 | void nfs_destroy_directcache(void) |
1da177e4 | 1078 | { |
1a1d92c1 | 1079 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 1080 | } |