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> | |
47 | ||
48 | #include <linux/nfs_fs.h> | |
49 | #include <linux/nfs_page.h> | |
50 | #include <linux/sunrpc/clnt.h> | |
51 | ||
52 | #include <asm/system.h> | |
53 | #include <asm/uaccess.h> | |
54 | #include <asm/atomic.h> | |
55 | ||
8d5658c9 | 56 | #include "internal.h" |
91d5b470 CL |
57 | #include "iostat.h" |
58 | ||
1da177e4 | 59 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 | 60 | |
e18b890b | 61 | static struct kmem_cache *nfs_direct_cachep; |
1da177e4 LT |
62 | |
63 | /* | |
64 | * This represents a set of asynchronous requests that we're waiting on | |
65 | */ | |
66 | struct nfs_direct_req { | |
67 | struct kref kref; /* release manager */ | |
15ce4a0c CL |
68 | |
69 | /* I/O parameters */ | |
a8881f5a | 70 | struct nfs_open_context *ctx; /* file open context info */ |
99514f8f | 71 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 72 | struct inode * inode; /* target file of i/o */ |
15ce4a0c CL |
73 | |
74 | /* completion state */ | |
607f31e8 | 75 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 76 | spinlock_t lock; /* protect completion state */ |
15ce4a0c | 77 | ssize_t count, /* bytes actually processed */ |
1da177e4 | 78 | error; /* any reported error */ |
d72b7a6b | 79 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
80 | |
81 | /* commit state */ | |
607f31e8 | 82 | struct list_head rewrite_list; /* saved nfs_write_data structs */ |
fad61490 TM |
83 | struct nfs_write_data * commit_data; /* special write_data for commits */ |
84 | int flags; | |
85 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ | |
86 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
87 | struct nfs_writeverf verf; /* unstable write verifier */ | |
1da177e4 LT |
88 | }; |
89 | ||
fad61490 | 90 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); |
607f31e8 TM |
91 | static const struct rpc_call_ops nfs_write_direct_ops; |
92 | ||
93 | static inline void get_dreq(struct nfs_direct_req *dreq) | |
94 | { | |
95 | atomic_inc(&dreq->io_count); | |
96 | } | |
97 | ||
98 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
99 | { | |
100 | return atomic_dec_and_test(&dreq->io_count); | |
101 | } | |
102 | ||
1da177e4 | 103 | /** |
b8a32e2b CL |
104 | * nfs_direct_IO - NFS address space operation for direct I/O |
105 | * @rw: direction (read or write) | |
106 | * @iocb: target I/O control block | |
107 | * @iov: array of vectors that define I/O buffer | |
108 | * @pos: offset in file to begin the operation | |
109 | * @nr_segs: size of iovec array | |
110 | * | |
111 | * The presence of this routine in the address space ops vector means | |
112 | * the NFS client supports direct I/O. However, we shunt off direct | |
113 | * read and write requests before the VFS gets them, so this method | |
114 | * should never be called. | |
1da177e4 | 115 | */ |
b8a32e2b CL |
116 | ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) |
117 | { | |
b8a32e2b | 118 | dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", |
01cce933 | 119 | iocb->ki_filp->f_path.dentry->d_name.name, |
e99170ff | 120 | (long long) pos, nr_segs); |
b8a32e2b CL |
121 | |
122 | return -EINVAL; | |
123 | } | |
124 | ||
d4a8f367 | 125 | static void nfs_direct_dirty_pages(struct page **pages, unsigned int pgbase, size_t count) |
6b45d858 | 126 | { |
d4a8f367 | 127 | unsigned int npages; |
749e146e | 128 | unsigned int i; |
d4a8f367 TM |
129 | |
130 | if (count == 0) | |
131 | return; | |
132 | pages += (pgbase >> PAGE_SHIFT); | |
133 | npages = (count + (pgbase & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
6b45d858 TM |
134 | for (i = 0; i < npages; i++) { |
135 | struct page *page = pages[i]; | |
607f31e8 | 136 | if (!PageCompound(page)) |
d4a8f367 | 137 | set_page_dirty(page); |
6b45d858 | 138 | } |
9c93ab7d CL |
139 | } |
140 | ||
749e146e | 141 | static void nfs_direct_release_pages(struct page **pages, unsigned int npages) |
9c93ab7d | 142 | { |
749e146e | 143 | unsigned int i; |
607f31e8 TM |
144 | for (i = 0; i < npages; i++) |
145 | page_cache_release(pages[i]); | |
6b45d858 TM |
146 | } |
147 | ||
93619e59 | 148 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 149 | { |
93619e59 CL |
150 | struct nfs_direct_req *dreq; |
151 | ||
e94b1766 | 152 | dreq = kmem_cache_alloc(nfs_direct_cachep, GFP_KERNEL); |
93619e59 CL |
153 | if (!dreq) |
154 | return NULL; | |
155 | ||
156 | kref_init(&dreq->kref); | |
607f31e8 | 157 | kref_get(&dreq->kref); |
d72b7a6b | 158 | init_completion(&dreq->completion); |
fad61490 | 159 | INIT_LIST_HEAD(&dreq->rewrite_list); |
93619e59 | 160 | dreq->iocb = NULL; |
a8881f5a | 161 | dreq->ctx = NULL; |
15ce4a0c | 162 | spin_lock_init(&dreq->lock); |
607f31e8 | 163 | atomic_set(&dreq->io_count, 0); |
15ce4a0c CL |
164 | dreq->count = 0; |
165 | dreq->error = 0; | |
fad61490 | 166 | dreq->flags = 0; |
93619e59 CL |
167 | |
168 | return dreq; | |
1da177e4 LT |
169 | } |
170 | ||
b4946ffb | 171 | static void nfs_direct_req_free(struct kref *kref) |
1da177e4 LT |
172 | { |
173 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a TM |
174 | |
175 | if (dreq->ctx != NULL) | |
176 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
177 | kmem_cache_free(nfs_direct_cachep, dreq); |
178 | } | |
179 | ||
b4946ffb TM |
180 | static void nfs_direct_req_release(struct nfs_direct_req *dreq) |
181 | { | |
182 | kref_put(&dreq->kref, nfs_direct_req_free); | |
183 | } | |
184 | ||
bc0fb201 CL |
185 | /* |
186 | * Collects and returns the final error value/byte-count. | |
187 | */ | |
188 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
189 | { | |
15ce4a0c | 190 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
191 | |
192 | /* Async requests don't wait here */ | |
193 | if (dreq->iocb) | |
194 | goto out; | |
195 | ||
150030b7 | 196 | result = wait_for_completion_killable(&dreq->completion); |
bc0fb201 CL |
197 | |
198 | if (!result) | |
15ce4a0c | 199 | result = dreq->error; |
bc0fb201 | 200 | if (!result) |
15ce4a0c | 201 | result = dreq->count; |
bc0fb201 CL |
202 | |
203 | out: | |
bc0fb201 CL |
204 | return (ssize_t) result; |
205 | } | |
206 | ||
63ab46ab | 207 | /* |
607f31e8 TM |
208 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
209 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
210 | */ |
211 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
212 | { | |
63ab46ab | 213 | if (dreq->iocb) { |
15ce4a0c | 214 | long res = (long) dreq->error; |
63ab46ab | 215 | if (!res) |
15ce4a0c | 216 | res = (long) dreq->count; |
63ab46ab | 217 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
218 | } |
219 | complete_all(&dreq->completion); | |
63ab46ab | 220 | |
b4946ffb | 221 | nfs_direct_req_release(dreq); |
63ab46ab CL |
222 | } |
223 | ||
06cf6f2e | 224 | /* |
607f31e8 TM |
225 | * We must hold a reference to all the pages in this direct read request |
226 | * until the RPCs complete. This could be long *after* we are woken up in | |
227 | * nfs_direct_wait (for instance, if someone hits ^C on a slow server). | |
06cf6f2e | 228 | */ |
ec06c096 | 229 | static void nfs_direct_read_result(struct rpc_task *task, void *calldata) |
1da177e4 | 230 | { |
ec06c096 | 231 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
232 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; |
233 | ||
ec06c096 TM |
234 | if (nfs_readpage_result(task, data) != 0) |
235 | return; | |
15ce4a0c CL |
236 | |
237 | spin_lock(&dreq->lock); | |
d4a8f367 | 238 | if (unlikely(task->tk_status < 0)) { |
15ce4a0c | 239 | dreq->error = task->tk_status; |
d4a8f367 TM |
240 | spin_unlock(&dreq->lock); |
241 | } else { | |
242 | dreq->count += data->res.count; | |
243 | spin_unlock(&dreq->lock); | |
244 | nfs_direct_dirty_pages(data->pagevec, | |
245 | data->args.pgbase, | |
246 | data->res.count); | |
247 | } | |
248 | nfs_direct_release_pages(data->pagevec, data->npages); | |
607f31e8 TM |
249 | |
250 | if (put_dreq(dreq)) | |
251 | nfs_direct_complete(dreq); | |
1da177e4 LT |
252 | } |
253 | ||
ec06c096 TM |
254 | static const struct rpc_call_ops nfs_read_direct_ops = { |
255 | .rpc_call_done = nfs_direct_read_result, | |
256 | .rpc_release = nfs_readdata_release, | |
257 | }; | |
258 | ||
d4cc948b | 259 | /* |
607f31e8 TM |
260 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
261 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
262 | * bail and stop sending more reads. Read length accounting is | |
263 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
264 | * no requests have been sent, just return an error. | |
1da177e4 | 265 | */ |
02fe4946 CL |
266 | static ssize_t nfs_direct_read_schedule_segment(struct nfs_direct_req *dreq, |
267 | const struct iovec *iov, | |
268 | loff_t pos) | |
1da177e4 | 269 | { |
a8881f5a | 270 | struct nfs_open_context *ctx = dreq->ctx; |
88be9f99 | 271 | struct inode *inode = ctx->path.dentry->d_inode; |
02fe4946 CL |
272 | unsigned long user_addr = (unsigned long)iov->iov_base; |
273 | size_t count = iov->iov_len; | |
5dd602f2 | 274 | size_t rsize = NFS_SERVER(inode)->rsize; |
07737691 | 275 | struct rpc_task *task; |
bdc7f021 TM |
276 | struct rpc_message msg = { |
277 | .rpc_cred = ctx->cred, | |
278 | }; | |
84115e1c TM |
279 | struct rpc_task_setup task_setup_data = { |
280 | .rpc_client = NFS_CLIENT(inode), | |
bdc7f021 | 281 | .rpc_message = &msg, |
84115e1c TM |
282 | .callback_ops = &nfs_read_direct_ops, |
283 | .flags = RPC_TASK_ASYNC, | |
284 | }; | |
607f31e8 TM |
285 | unsigned int pgbase; |
286 | int result; | |
287 | ssize_t started = 0; | |
288 | ||
1da177e4 | 289 | do { |
82b145c5 | 290 | struct nfs_read_data *data; |
5dd602f2 | 291 | size_t bytes; |
1da177e4 | 292 | |
e9f7bee1 TM |
293 | pgbase = user_addr & ~PAGE_MASK; |
294 | bytes = min(rsize,count); | |
295 | ||
607f31e8 | 296 | result = -ENOMEM; |
8d5658c9 | 297 | data = nfs_readdata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
298 | if (unlikely(!data)) |
299 | break; | |
300 | ||
607f31e8 TM |
301 | down_read(¤t->mm->mmap_sem); |
302 | result = get_user_pages(current, current->mm, user_addr, | |
303 | data->npages, 1, 0, data->pagevec, NULL); | |
304 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
305 | if (result < 0) { |
306 | nfs_readdata_release(data); | |
307 | break; | |
308 | } | |
309 | if ((unsigned)result < data->npages) { | |
d9df8d6b TM |
310 | bytes = result * PAGE_SIZE; |
311 | if (bytes <= pgbase) { | |
312 | nfs_direct_release_pages(data->pagevec, result); | |
313 | nfs_readdata_release(data); | |
314 | break; | |
315 | } | |
316 | bytes -= pgbase; | |
317 | data->npages = result; | |
607f31e8 TM |
318 | } |
319 | ||
320 | get_dreq(dreq); | |
82b145c5 | 321 | |
607f31e8 | 322 | data->req = (struct nfs_page *) dreq; |
1da177e4 | 323 | data->inode = inode; |
bdc7f021 | 324 | data->cred = msg.rpc_cred; |
1da177e4 LT |
325 | data->args.fh = NFS_FH(inode); |
326 | data->args.context = ctx; | |
88467055 | 327 | data->args.offset = pos; |
1da177e4 | 328 | data->args.pgbase = pgbase; |
607f31e8 | 329 | data->args.pages = data->pagevec; |
1da177e4 LT |
330 | data->args.count = bytes; |
331 | data->res.fattr = &data->fattr; | |
332 | data->res.eof = 0; | |
333 | data->res.count = bytes; | |
bdc7f021 TM |
334 | msg.rpc_argp = &data->args; |
335 | msg.rpc_resp = &data->res; | |
1da177e4 | 336 | |
07737691 | 337 | task_setup_data.task = &data->task; |
84115e1c | 338 | task_setup_data.callback_data = data; |
bdc7f021 | 339 | NFS_PROTO(inode)->read_setup(data, &msg); |
1da177e4 | 340 | |
07737691 TM |
341 | task = rpc_run_task(&task_setup_data); |
342 | if (!IS_ERR(task)) | |
343 | rpc_put_task(task); | |
1da177e4 | 344 | |
a3f565b1 CL |
345 | dprintk("NFS: %5u initiated direct read call " |
346 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
1da177e4 LT |
347 | data->task.tk_pid, |
348 | inode->i_sb->s_id, | |
349 | (long long)NFS_FILEID(inode), | |
350 | bytes, | |
351 | (unsigned long long)data->args.offset); | |
352 | ||
607f31e8 TM |
353 | started += bytes; |
354 | user_addr += bytes; | |
88467055 | 355 | pos += bytes; |
e9f7bee1 | 356 | /* FIXME: Remove this unnecessary math from final patch */ |
1da177e4 | 357 | pgbase += bytes; |
1da177e4 | 358 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 359 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 LT |
360 | |
361 | count -= bytes; | |
362 | } while (count != 0); | |
607f31e8 | 363 | |
607f31e8 | 364 | if (started) |
c216fd70 | 365 | return started; |
607f31e8 | 366 | return result < 0 ? (ssize_t) result : -EFAULT; |
1da177e4 LT |
367 | } |
368 | ||
19f73787 CL |
369 | static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, |
370 | const struct iovec *iov, | |
371 | unsigned long nr_segs, | |
372 | loff_t pos) | |
373 | { | |
374 | ssize_t result = -EINVAL; | |
375 | size_t requested_bytes = 0; | |
376 | unsigned long seg; | |
377 | ||
378 | get_dreq(dreq); | |
379 | ||
380 | for (seg = 0; seg < nr_segs; seg++) { | |
381 | const struct iovec *vec = &iov[seg]; | |
02fe4946 | 382 | result = nfs_direct_read_schedule_segment(dreq, vec, pos); |
19f73787 CL |
383 | if (result < 0) |
384 | break; | |
385 | requested_bytes += result; | |
386 | if ((size_t)result < vec->iov_len) | |
387 | break; | |
388 | pos += vec->iov_len; | |
389 | } | |
390 | ||
391 | if (put_dreq(dreq)) | |
392 | nfs_direct_complete(dreq); | |
393 | ||
394 | if (requested_bytes != 0) | |
395 | return 0; | |
396 | ||
397 | if (result < 0) | |
398 | return result; | |
399 | return -EIO; | |
400 | } | |
401 | ||
c216fd70 CL |
402 | static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, |
403 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 404 | { |
607f31e8 | 405 | ssize_t result = 0; |
99514f8f | 406 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
407 | struct nfs_direct_req *dreq; |
408 | ||
607f31e8 | 409 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
410 | if (!dreq) |
411 | return -ENOMEM; | |
412 | ||
91d5b470 | 413 | dreq->inode = inode; |
cd3758e3 | 414 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
487b8372 CL |
415 | if (!is_sync_kiocb(iocb)) |
416 | dreq->iocb = iocb; | |
1da177e4 | 417 | |
c216fd70 | 418 | result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos); |
607f31e8 TM |
419 | if (!result) |
420 | result = nfs_direct_wait(dreq); | |
b4946ffb | 421 | nfs_direct_req_release(dreq); |
1da177e4 LT |
422 | |
423 | return result; | |
424 | } | |
425 | ||
fad61490 | 426 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 427 | { |
607f31e8 TM |
428 | while (!list_empty(&dreq->rewrite_list)) { |
429 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 430 | list_del(&data->pages); |
607f31e8 | 431 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
432 | nfs_writedata_release(data); |
433 | } | |
434 | } | |
1da177e4 | 435 | |
fad61490 TM |
436 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
437 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
438 | { | |
607f31e8 TM |
439 | struct inode *inode = dreq->inode; |
440 | struct list_head *p; | |
441 | struct nfs_write_data *data; | |
07737691 | 442 | struct rpc_task *task; |
bdc7f021 TM |
443 | struct rpc_message msg = { |
444 | .rpc_cred = dreq->ctx->cred, | |
445 | }; | |
84115e1c TM |
446 | struct rpc_task_setup task_setup_data = { |
447 | .rpc_client = NFS_CLIENT(inode), | |
448 | .callback_ops = &nfs_write_direct_ops, | |
449 | .flags = RPC_TASK_ASYNC, | |
450 | }; | |
1da177e4 | 451 | |
fad61490 | 452 | dreq->count = 0; |
607f31e8 TM |
453 | get_dreq(dreq); |
454 | ||
455 | list_for_each(p, &dreq->rewrite_list) { | |
456 | data = list_entry(p, struct nfs_write_data, pages); | |
457 | ||
458 | get_dreq(dreq); | |
459 | ||
bdc7f021 TM |
460 | /* Use stable writes */ |
461 | data->args.stable = NFS_FILE_SYNC; | |
462 | ||
607f31e8 TM |
463 | /* |
464 | * Reset data->res. | |
465 | */ | |
466 | nfs_fattr_init(&data->fattr); | |
467 | data->res.count = data->args.count; | |
468 | memset(&data->verf, 0, sizeof(data->verf)); | |
469 | ||
470 | /* | |
471 | * Reuse data->task; data->args should not have changed | |
472 | * since the original request was sent. | |
473 | */ | |
07737691 | 474 | task_setup_data.task = &data->task; |
84115e1c | 475 | task_setup_data.callback_data = data; |
bdc7f021 TM |
476 | msg.rpc_argp = &data->args; |
477 | msg.rpc_resp = &data->res; | |
478 | NFS_PROTO(inode)->write_setup(data, &msg); | |
607f31e8 | 479 | |
607f31e8 TM |
480 | /* |
481 | * We're called via an RPC callback, so BKL is already held. | |
482 | */ | |
07737691 TM |
483 | task = rpc_run_task(&task_setup_data); |
484 | if (!IS_ERR(task)) | |
485 | rpc_put_task(task); | |
607f31e8 TM |
486 | |
487 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
488 | data->task.tk_pid, | |
489 | inode->i_sb->s_id, | |
490 | (long long)NFS_FILEID(inode), | |
491 | data->args.count, | |
492 | (unsigned long long)data->args.offset); | |
493 | } | |
fedb595c | 494 | |
607f31e8 TM |
495 | if (put_dreq(dreq)) |
496 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
497 | } |
498 | ||
499 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
500 | { | |
501 | struct nfs_write_data *data = calldata; | |
502 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
503 | ||
504 | /* Call the NFS version-specific code */ | |
505 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
506 | return; | |
507 | if (unlikely(task->tk_status < 0)) { | |
60fa3f76 TM |
508 | dprintk("NFS: %5u commit failed with error %d.\n", |
509 | task->tk_pid, task->tk_status); | |
fad61490 | 510 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
60fa3f76 | 511 | } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { |
fad61490 TM |
512 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); |
513 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
514 | } |
515 | ||
fad61490 TM |
516 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
517 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
518 | } |
519 | ||
fad61490 TM |
520 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
521 | .rpc_call_done = nfs_direct_commit_result, | |
522 | .rpc_release = nfs_commit_release, | |
523 | }; | |
524 | ||
525 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 526 | { |
fad61490 | 527 | struct nfs_write_data *data = dreq->commit_data; |
07737691 | 528 | struct rpc_task *task; |
bdc7f021 TM |
529 | struct rpc_message msg = { |
530 | .rpc_argp = &data->args, | |
531 | .rpc_resp = &data->res, | |
532 | .rpc_cred = dreq->ctx->cred, | |
533 | }; | |
84115e1c | 534 | struct rpc_task_setup task_setup_data = { |
07737691 | 535 | .task = &data->task, |
84115e1c | 536 | .rpc_client = NFS_CLIENT(dreq->inode), |
bdc7f021 | 537 | .rpc_message = &msg, |
84115e1c TM |
538 | .callback_ops = &nfs_commit_direct_ops, |
539 | .callback_data = data, | |
540 | .flags = RPC_TASK_ASYNC, | |
541 | }; | |
1da177e4 | 542 | |
fad61490 | 543 | data->inode = dreq->inode; |
bdc7f021 | 544 | data->cred = msg.rpc_cred; |
1da177e4 | 545 | |
fad61490 | 546 | data->args.fh = NFS_FH(data->inode); |
607f31e8 TM |
547 | data->args.offset = 0; |
548 | data->args.count = 0; | |
fad61490 TM |
549 | data->res.count = 0; |
550 | data->res.fattr = &data->fattr; | |
551 | data->res.verf = &data->verf; | |
1da177e4 | 552 | |
bdc7f021 | 553 | NFS_PROTO(data->inode)->commit_setup(data, &msg); |
1da177e4 | 554 | |
fad61490 TM |
555 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ |
556 | dreq->commit_data = NULL; | |
1da177e4 | 557 | |
e99170ff | 558 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 559 | |
07737691 TM |
560 | task = rpc_run_task(&task_setup_data); |
561 | if (!IS_ERR(task)) | |
562 | rpc_put_task(task); | |
fad61490 | 563 | } |
1da177e4 | 564 | |
fad61490 TM |
565 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
566 | { | |
567 | int flags = dreq->flags; | |
1da177e4 | 568 | |
fad61490 TM |
569 | dreq->flags = 0; |
570 | switch (flags) { | |
571 | case NFS_ODIRECT_DO_COMMIT: | |
572 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 573 | break; |
fad61490 TM |
574 | case NFS_ODIRECT_RESCHED_WRITES: |
575 | nfs_direct_write_reschedule(dreq); | |
576 | break; | |
577 | default: | |
fad61490 TM |
578 | if (dreq->commit_data != NULL) |
579 | nfs_commit_free(dreq->commit_data); | |
580 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 581 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
582 | nfs_direct_complete(dreq); |
583 | } | |
584 | } | |
1da177e4 | 585 | |
fad61490 TM |
586 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
587 | { | |
e9f7bee1 | 588 | dreq->commit_data = nfs_commit_alloc(); |
fad61490 TM |
589 | if (dreq->commit_data != NULL) |
590 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
591 | } | |
592 | #else | |
593 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
594 | { | |
595 | dreq->commit_data = NULL; | |
596 | } | |
1da177e4 | 597 | |
fad61490 TM |
598 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
599 | { | |
fad61490 | 600 | nfs_direct_free_writedata(dreq); |
cd9ae2b6 | 601 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
602 | nfs_direct_complete(dreq); |
603 | } | |
604 | #endif | |
1da177e4 | 605 | |
462d5b32 | 606 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 607 | { |
462d5b32 CL |
608 | struct nfs_write_data *data = calldata; |
609 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
610 | int status = task->tk_status; | |
611 | ||
612 | if (nfs_writeback_done(task, data) != 0) | |
613 | return; | |
462d5b32 | 614 | |
15ce4a0c | 615 | spin_lock(&dreq->lock); |
1da177e4 | 616 | |
eda3cef8 | 617 | if (unlikely(status < 0)) { |
432409ee | 618 | /* An error has occurred, so we should not commit */ |
60fa3f76 | 619 | dreq->flags = 0; |
eda3cef8 | 620 | dreq->error = status; |
eda3cef8 | 621 | } |
432409ee NB |
622 | if (unlikely(dreq->error != 0)) |
623 | goto out_unlock; | |
eda3cef8 TM |
624 | |
625 | dreq->count += data->res.count; | |
1da177e4 | 626 | |
fad61490 TM |
627 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
628 | switch (dreq->flags) { | |
629 | case 0: | |
630 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
631 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 632 | break; |
fad61490 TM |
633 | case NFS_ODIRECT_DO_COMMIT: |
634 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
635 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
636 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
637 | } | |
1da177e4 | 638 | } |
1da177e4 | 639 | } |
eda3cef8 | 640 | out_unlock: |
fad61490 | 641 | spin_unlock(&dreq->lock); |
1da177e4 LT |
642 | } |
643 | ||
fad61490 TM |
644 | /* |
645 | * NB: Return the value of the first error return code. Subsequent | |
646 | * errors after the first one are ignored. | |
1da177e4 | 647 | */ |
fad61490 | 648 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 649 | { |
fad61490 TM |
650 | struct nfs_write_data *data = calldata; |
651 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 652 | |
607f31e8 TM |
653 | if (put_dreq(dreq)) |
654 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
655 | } |
656 | ||
657 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
658 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 659 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
660 | }; |
661 | ||
662 | /* | |
607f31e8 TM |
663 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
664 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
665 | * bail and stop sending more writes. Write length accounting is | |
666 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
667 | * no requests have been sent, just return an error. | |
462d5b32 | 668 | */ |
02fe4946 CL |
669 | static ssize_t nfs_direct_write_schedule_segment(struct nfs_direct_req *dreq, |
670 | const struct iovec *iov, | |
671 | loff_t pos, int sync) | |
462d5b32 | 672 | { |
a8881f5a | 673 | struct nfs_open_context *ctx = dreq->ctx; |
88be9f99 | 674 | struct inode *inode = ctx->path.dentry->d_inode; |
02fe4946 CL |
675 | unsigned long user_addr = (unsigned long)iov->iov_base; |
676 | size_t count = iov->iov_len; | |
07737691 | 677 | struct rpc_task *task; |
bdc7f021 TM |
678 | struct rpc_message msg = { |
679 | .rpc_cred = ctx->cred, | |
680 | }; | |
84115e1c TM |
681 | struct rpc_task_setup task_setup_data = { |
682 | .rpc_client = NFS_CLIENT(inode), | |
bdc7f021 | 683 | .rpc_message = &msg, |
84115e1c TM |
684 | .callback_ops = &nfs_write_direct_ops, |
685 | .flags = RPC_TASK_ASYNC, | |
686 | }; | |
462d5b32 | 687 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
688 | unsigned int pgbase; |
689 | int result; | |
690 | ssize_t started = 0; | |
82b145c5 | 691 | |
1da177e4 | 692 | do { |
82b145c5 | 693 | struct nfs_write_data *data; |
462d5b32 CL |
694 | size_t bytes; |
695 | ||
e9f7bee1 TM |
696 | pgbase = user_addr & ~PAGE_MASK; |
697 | bytes = min(wsize,count); | |
698 | ||
607f31e8 | 699 | result = -ENOMEM; |
8d5658c9 | 700 | data = nfs_writedata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
701 | if (unlikely(!data)) |
702 | break; | |
703 | ||
607f31e8 TM |
704 | down_read(¤t->mm->mmap_sem); |
705 | result = get_user_pages(current, current->mm, user_addr, | |
706 | data->npages, 0, 0, data->pagevec, NULL); | |
707 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
708 | if (result < 0) { |
709 | nfs_writedata_release(data); | |
710 | break; | |
711 | } | |
712 | if ((unsigned)result < data->npages) { | |
d9df8d6b TM |
713 | bytes = result * PAGE_SIZE; |
714 | if (bytes <= pgbase) { | |
715 | nfs_direct_release_pages(data->pagevec, result); | |
716 | nfs_writedata_release(data); | |
717 | break; | |
718 | } | |
719 | bytes -= pgbase; | |
720 | data->npages = result; | |
607f31e8 TM |
721 | } |
722 | ||
723 | get_dreq(dreq); | |
724 | ||
fad61490 | 725 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 726 | |
607f31e8 | 727 | data->req = (struct nfs_page *) dreq; |
462d5b32 | 728 | data->inode = inode; |
bdc7f021 | 729 | data->cred = msg.rpc_cred; |
462d5b32 CL |
730 | data->args.fh = NFS_FH(inode); |
731 | data->args.context = ctx; | |
88467055 | 732 | data->args.offset = pos; |
462d5b32 | 733 | data->args.pgbase = pgbase; |
607f31e8 | 734 | data->args.pages = data->pagevec; |
462d5b32 | 735 | data->args.count = bytes; |
bdc7f021 | 736 | data->args.stable = sync; |
462d5b32 CL |
737 | data->res.fattr = &data->fattr; |
738 | data->res.count = bytes; | |
47989d74 | 739 | data->res.verf = &data->verf; |
462d5b32 | 740 | |
07737691 | 741 | task_setup_data.task = &data->task; |
84115e1c | 742 | task_setup_data.callback_data = data; |
bdc7f021 TM |
743 | msg.rpc_argp = &data->args; |
744 | msg.rpc_resp = &data->res; | |
745 | NFS_PROTO(inode)->write_setup(data, &msg); | |
1da177e4 | 746 | |
07737691 TM |
747 | task = rpc_run_task(&task_setup_data); |
748 | if (!IS_ERR(task)) | |
749 | rpc_put_task(task); | |
1da177e4 | 750 | |
a3f565b1 CL |
751 | dprintk("NFS: %5u initiated direct write call " |
752 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
462d5b32 CL |
753 | data->task.tk_pid, |
754 | inode->i_sb->s_id, | |
755 | (long long)NFS_FILEID(inode), | |
756 | bytes, | |
757 | (unsigned long long)data->args.offset); | |
1da177e4 | 758 | |
607f31e8 TM |
759 | started += bytes; |
760 | user_addr += bytes; | |
88467055 | 761 | pos += bytes; |
e9f7bee1 TM |
762 | |
763 | /* FIXME: Remove this useless math from the final patch */ | |
462d5b32 | 764 | pgbase += bytes; |
462d5b32 | 765 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 766 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 | 767 | |
462d5b32 CL |
768 | count -= bytes; |
769 | } while (count != 0); | |
607f31e8 | 770 | |
607f31e8 | 771 | if (started) |
c216fd70 | 772 | return started; |
607f31e8 | 773 | return result < 0 ? (ssize_t) result : -EFAULT; |
462d5b32 | 774 | } |
1da177e4 | 775 | |
19f73787 CL |
776 | static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, |
777 | const struct iovec *iov, | |
778 | unsigned long nr_segs, | |
779 | loff_t pos, int sync) | |
780 | { | |
781 | ssize_t result = 0; | |
782 | size_t requested_bytes = 0; | |
783 | unsigned long seg; | |
784 | ||
785 | get_dreq(dreq); | |
786 | ||
787 | for (seg = 0; seg < nr_segs; seg++) { | |
788 | const struct iovec *vec = &iov[seg]; | |
02fe4946 CL |
789 | result = nfs_direct_write_schedule_segment(dreq, vec, |
790 | pos, sync); | |
19f73787 CL |
791 | if (result < 0) |
792 | break; | |
793 | requested_bytes += result; | |
794 | if ((size_t)result < vec->iov_len) | |
795 | break; | |
796 | pos += vec->iov_len; | |
797 | } | |
798 | ||
799 | if (put_dreq(dreq)) | |
800 | nfs_direct_write_complete(dreq, dreq->inode); | |
801 | ||
802 | if (requested_bytes != 0) | |
803 | return 0; | |
804 | ||
805 | if (result < 0) | |
806 | return result; | |
807 | return -EIO; | |
808 | } | |
809 | ||
c216fd70 CL |
810 | static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, |
811 | unsigned long nr_segs, loff_t pos, | |
812 | size_t count) | |
462d5b32 | 813 | { |
607f31e8 | 814 | ssize_t result = 0; |
c89f2ee5 | 815 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 | 816 | struct nfs_direct_req *dreq; |
fad61490 | 817 | size_t wsize = NFS_SERVER(inode)->wsize; |
bdc7f021 | 818 | int sync = NFS_UNSTABLE; |
1da177e4 | 819 | |
607f31e8 | 820 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
821 | if (!dreq) |
822 | return -ENOMEM; | |
607f31e8 TM |
823 | nfs_alloc_commit_data(dreq); |
824 | ||
fad61490 | 825 | if (dreq->commit_data == NULL || count < wsize) |
bdc7f021 | 826 | sync = NFS_FILE_SYNC; |
1da177e4 | 827 | |
c89f2ee5 | 828 | dreq->inode = inode; |
cd3758e3 | 829 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
c89f2ee5 CL |
830 | if (!is_sync_kiocb(iocb)) |
831 | dreq->iocb = iocb; | |
1da177e4 | 832 | |
c216fd70 | 833 | result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, sync); |
607f31e8 TM |
834 | if (!result) |
835 | result = nfs_direct_wait(dreq); | |
b4946ffb | 836 | nfs_direct_req_release(dreq); |
1da177e4 | 837 | |
1da177e4 LT |
838 | return result; |
839 | } | |
840 | ||
841 | /** | |
842 | * nfs_file_direct_read - file direct read operation for NFS files | |
843 | * @iocb: target I/O control block | |
027445c3 BP |
844 | * @iov: vector of user buffers into which to read data |
845 | * @nr_segs: size of iov vector | |
88467055 | 846 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
847 | * |
848 | * We use this function for direct reads instead of calling | |
849 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
850 | * the request starts before the end of the file. For that check | |
851 | * to work, we must generate a GETATTR before each direct read, and | |
852 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 853 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
854 | * to do all reads the application wants, and the server will take |
855 | * care of managing the end of file boundary. | |
88467055 | 856 | * |
1da177e4 LT |
857 | * This function also eliminates unnecessarily updating the file's |
858 | * atime locally, as the NFS server sets the file's atime, and this | |
859 | * client must read the updated atime from the server back into its | |
860 | * cache. | |
861 | */ | |
027445c3 BP |
862 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
863 | unsigned long nr_segs, loff_t pos) | |
1da177e4 LT |
864 | { |
865 | ssize_t retval = -EINVAL; | |
1da177e4 | 866 | struct file *file = iocb->ki_filp; |
1da177e4 | 867 | struct address_space *mapping = file->f_mapping; |
c216fd70 CL |
868 | size_t count; |
869 | ||
870 | count = iov_length(iov, nr_segs); | |
871 | nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); | |
1da177e4 | 872 | |
c216fd70 | 873 | dprintk("nfs: direct read(%s/%s, %zd@%Ld)\n", |
01cce933 JJS |
874 | file->f_path.dentry->d_parent->d_name.name, |
875 | file->f_path.dentry->d_name.name, | |
c216fd70 | 876 | count, (long long) pos); |
1da177e4 | 877 | |
1da177e4 LT |
878 | retval = 0; |
879 | if (!count) | |
880 | goto out; | |
881 | ||
29884df0 TM |
882 | retval = nfs_sync_mapping(mapping); |
883 | if (retval) | |
884 | goto out; | |
1da177e4 | 885 | |
c216fd70 | 886 | retval = nfs_direct_read(iocb, iov, nr_segs, pos); |
1da177e4 | 887 | if (retval > 0) |
0cdd80d0 | 888 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
889 | |
890 | out: | |
891 | return retval; | |
892 | } | |
893 | ||
894 | /** | |
895 | * nfs_file_direct_write - file direct write operation for NFS files | |
896 | * @iocb: target I/O control block | |
027445c3 BP |
897 | * @iov: vector of user buffers from which to write data |
898 | * @nr_segs: size of iov vector | |
88467055 | 899 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
900 | * |
901 | * We use this function for direct writes instead of calling | |
902 | * generic_file_aio_write() in order to avoid taking the inode | |
903 | * semaphore and updating the i_size. The NFS server will set | |
904 | * the new i_size and this client must read the updated size | |
905 | * back into its cache. We let the server do generic write | |
906 | * parameter checking and report problems. | |
907 | * | |
908 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
909 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
910 | * | |
911 | * We eliminate local atime updates, see direct read above. | |
912 | * | |
913 | * We avoid unnecessary page cache invalidations for normal cached | |
914 | * readers of this file. | |
915 | * | |
916 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
917 | * is no atomic O_APPEND write facility in the NFS protocol. | |
918 | */ | |
027445c3 BP |
919 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
920 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 921 | { |
070ea602 | 922 | ssize_t retval = -EINVAL; |
1da177e4 | 923 | struct file *file = iocb->ki_filp; |
1da177e4 | 924 | struct address_space *mapping = file->f_mapping; |
c216fd70 | 925 | size_t count; |
1da177e4 | 926 | |
c216fd70 CL |
927 | count = iov_length(iov, nr_segs); |
928 | nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); | |
929 | ||
930 | dfprintk(VFS, "nfs: direct write(%s/%s, %zd@%Ld)\n", | |
01cce933 JJS |
931 | file->f_path.dentry->d_parent->d_name.name, |
932 | file->f_path.dentry->d_name.name, | |
c216fd70 | 933 | count, (long long) pos); |
027445c3 | 934 | |
ce1a8e67 CL |
935 | retval = generic_write_checks(file, &pos, &count, 0); |
936 | if (retval) | |
1da177e4 | 937 | goto out; |
ce1a8e67 CL |
938 | |
939 | retval = -EINVAL; | |
940 | if ((ssize_t) count < 0) | |
1da177e4 | 941 | goto out; |
1da177e4 LT |
942 | retval = 0; |
943 | if (!count) | |
944 | goto out; | |
ce1a8e67 | 945 | |
29884df0 TM |
946 | retval = nfs_sync_mapping(mapping); |
947 | if (retval) | |
948 | goto out; | |
1da177e4 | 949 | |
c216fd70 | 950 | retval = nfs_direct_write(iocb, iov, nr_segs, pos, count); |
9eafa8cc | 951 | |
1da177e4 | 952 | if (retval > 0) |
ce1a8e67 | 953 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
954 | |
955 | out: | |
956 | return retval; | |
957 | } | |
958 | ||
88467055 CL |
959 | /** |
960 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
961 | * | |
962 | */ | |
f7b422b1 | 963 | int __init nfs_init_directcache(void) |
1da177e4 LT |
964 | { |
965 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
966 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
967 | 0, (SLAB_RECLAIM_ACCOUNT| |
968 | SLAB_MEM_SPREAD), | |
20c2df83 | 969 | NULL); |
1da177e4 LT |
970 | if (nfs_direct_cachep == NULL) |
971 | return -ENOMEM; | |
972 | ||
973 | return 0; | |
974 | } | |
975 | ||
88467055 | 976 | /** |
f7b422b1 | 977 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
978 | * |
979 | */ | |
266bee88 | 980 | void nfs_destroy_directcache(void) |
1da177e4 | 981 | { |
1a1d92c1 | 982 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 983 | } |