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 | ||
d72b7a6b | 196 | result = wait_for_completion_interruptible(&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 | */ |
607f31e8 | 266 | static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 267 | { |
a8881f5a TM |
268 | struct nfs_open_context *ctx = dreq->ctx; |
269 | struct inode *inode = ctx->dentry->d_inode; | |
5dd602f2 | 270 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
271 | unsigned int pgbase; |
272 | int result; | |
273 | ssize_t started = 0; | |
274 | ||
275 | get_dreq(dreq); | |
1da177e4 | 276 | |
1da177e4 | 277 | do { |
82b145c5 | 278 | struct nfs_read_data *data; |
5dd602f2 | 279 | size_t bytes; |
1da177e4 | 280 | |
e9f7bee1 TM |
281 | pgbase = user_addr & ~PAGE_MASK; |
282 | bytes = min(rsize,count); | |
283 | ||
607f31e8 | 284 | result = -ENOMEM; |
8d5658c9 | 285 | data = nfs_readdata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
286 | if (unlikely(!data)) |
287 | break; | |
288 | ||
607f31e8 TM |
289 | down_read(¤t->mm->mmap_sem); |
290 | result = get_user_pages(current, current->mm, user_addr, | |
291 | data->npages, 1, 0, data->pagevec, NULL); | |
292 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
293 | if (result < 0) { |
294 | nfs_readdata_release(data); | |
295 | break; | |
296 | } | |
297 | if ((unsigned)result < data->npages) { | |
298 | nfs_direct_release_pages(data->pagevec, result); | |
607f31e8 TM |
299 | nfs_readdata_release(data); |
300 | break; | |
301 | } | |
302 | ||
303 | get_dreq(dreq); | |
82b145c5 | 304 | |
607f31e8 | 305 | data->req = (struct nfs_page *) dreq; |
1da177e4 LT |
306 | data->inode = inode; |
307 | data->cred = ctx->cred; | |
308 | data->args.fh = NFS_FH(inode); | |
309 | data->args.context = ctx; | |
88467055 | 310 | data->args.offset = pos; |
1da177e4 | 311 | data->args.pgbase = pgbase; |
607f31e8 | 312 | data->args.pages = data->pagevec; |
1da177e4 LT |
313 | data->args.count = bytes; |
314 | data->res.fattr = &data->fattr; | |
315 | data->res.eof = 0; | |
316 | data->res.count = bytes; | |
317 | ||
ec06c096 TM |
318 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
319 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
320 | NFS_PROTO(inode)->read_setup(data); |
321 | ||
322 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 323 | |
1da177e4 | 324 | rpc_execute(&data->task); |
1da177e4 | 325 | |
a3f565b1 CL |
326 | dprintk("NFS: %5u initiated direct read call " |
327 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
1da177e4 LT |
328 | data->task.tk_pid, |
329 | inode->i_sb->s_id, | |
330 | (long long)NFS_FILEID(inode), | |
331 | bytes, | |
332 | (unsigned long long)data->args.offset); | |
333 | ||
607f31e8 TM |
334 | started += bytes; |
335 | user_addr += bytes; | |
88467055 | 336 | pos += bytes; |
e9f7bee1 | 337 | /* FIXME: Remove this unnecessary math from final patch */ |
1da177e4 | 338 | pgbase += bytes; |
1da177e4 | 339 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 340 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 LT |
341 | |
342 | count -= bytes; | |
343 | } while (count != 0); | |
607f31e8 TM |
344 | |
345 | if (put_dreq(dreq)) | |
346 | nfs_direct_complete(dreq); | |
347 | ||
348 | if (started) | |
349 | return 0; | |
350 | return result < 0 ? (ssize_t) result : -EFAULT; | |
1da177e4 LT |
351 | } |
352 | ||
607f31e8 | 353 | static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 354 | { |
607f31e8 | 355 | ssize_t result = 0; |
1da177e4 | 356 | sigset_t oldset; |
99514f8f | 357 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
358 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
359 | struct nfs_direct_req *dreq; | |
360 | ||
607f31e8 | 361 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
362 | if (!dreq) |
363 | return -ENOMEM; | |
364 | ||
91d5b470 | 365 | dreq->inode = inode; |
a8881f5a | 366 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
487b8372 CL |
367 | if (!is_sync_kiocb(iocb)) |
368 | dreq->iocb = iocb; | |
1da177e4 | 369 | |
91d5b470 | 370 | nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); |
1da177e4 | 371 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
372 | result = nfs_direct_read_schedule(dreq, user_addr, count, pos); |
373 | if (!result) | |
374 | result = nfs_direct_wait(dreq); | |
1da177e4 | 375 | rpc_clnt_sigunmask(clnt, &oldset); |
b4946ffb | 376 | nfs_direct_req_release(dreq); |
1da177e4 LT |
377 | |
378 | return result; | |
379 | } | |
380 | ||
fad61490 | 381 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 382 | { |
607f31e8 TM |
383 | while (!list_empty(&dreq->rewrite_list)) { |
384 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 385 | list_del(&data->pages); |
607f31e8 | 386 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
387 | nfs_writedata_release(data); |
388 | } | |
389 | } | |
1da177e4 | 390 | |
fad61490 TM |
391 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
392 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
393 | { | |
607f31e8 TM |
394 | struct inode *inode = dreq->inode; |
395 | struct list_head *p; | |
396 | struct nfs_write_data *data; | |
1da177e4 | 397 | |
fad61490 | 398 | dreq->count = 0; |
607f31e8 TM |
399 | get_dreq(dreq); |
400 | ||
401 | list_for_each(p, &dreq->rewrite_list) { | |
402 | data = list_entry(p, struct nfs_write_data, pages); | |
403 | ||
404 | get_dreq(dreq); | |
405 | ||
406 | /* | |
407 | * Reset data->res. | |
408 | */ | |
409 | nfs_fattr_init(&data->fattr); | |
410 | data->res.count = data->args.count; | |
411 | memset(&data->verf, 0, sizeof(data->verf)); | |
412 | ||
413 | /* | |
414 | * Reuse data->task; data->args should not have changed | |
415 | * since the original request was sent. | |
416 | */ | |
417 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
418 | &nfs_write_direct_ops, data); | |
419 | NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); | |
420 | ||
421 | data->task.tk_priority = RPC_PRIORITY_NORMAL; | |
422 | data->task.tk_cookie = (unsigned long) inode; | |
423 | ||
424 | /* | |
425 | * We're called via an RPC callback, so BKL is already held. | |
426 | */ | |
427 | rpc_execute(&data->task); | |
428 | ||
429 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
430 | data->task.tk_pid, | |
431 | inode->i_sb->s_id, | |
432 | (long long)NFS_FILEID(inode), | |
433 | data->args.count, | |
434 | (unsigned long long)data->args.offset); | |
435 | } | |
fedb595c | 436 | |
607f31e8 TM |
437 | if (put_dreq(dreq)) |
438 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
439 | } |
440 | ||
441 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
442 | { | |
443 | struct nfs_write_data *data = calldata; | |
444 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
445 | ||
446 | /* Call the NFS version-specific code */ | |
447 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
448 | return; | |
449 | if (unlikely(task->tk_status < 0)) { | |
60fa3f76 TM |
450 | dprintk("NFS: %5u commit failed with error %d.\n", |
451 | task->tk_pid, task->tk_status); | |
fad61490 | 452 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
60fa3f76 | 453 | } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { |
fad61490 TM |
454 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); |
455 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
456 | } |
457 | ||
fad61490 TM |
458 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
459 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
460 | } |
461 | ||
fad61490 TM |
462 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
463 | .rpc_call_done = nfs_direct_commit_result, | |
464 | .rpc_release = nfs_commit_release, | |
465 | }; | |
466 | ||
467 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 468 | { |
fad61490 | 469 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 470 | |
fad61490 | 471 | data->inode = dreq->inode; |
a8881f5a | 472 | data->cred = dreq->ctx->cred; |
1da177e4 | 473 | |
fad61490 | 474 | data->args.fh = NFS_FH(data->inode); |
607f31e8 TM |
475 | data->args.offset = 0; |
476 | data->args.count = 0; | |
fad61490 TM |
477 | data->res.count = 0; |
478 | data->res.fattr = &data->fattr; | |
479 | data->res.verf = &data->verf; | |
1da177e4 | 480 | |
fad61490 TM |
481 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
482 | &nfs_commit_direct_ops, data); | |
483 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 484 | |
fad61490 TM |
485 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
486 | data->task.tk_cookie = (unsigned long)data->inode; | |
487 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
488 | dreq->commit_data = NULL; | |
1da177e4 | 489 | |
e99170ff | 490 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 491 | |
fad61490 | 492 | rpc_execute(&data->task); |
fad61490 | 493 | } |
1da177e4 | 494 | |
fad61490 TM |
495 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
496 | { | |
497 | int flags = dreq->flags; | |
1da177e4 | 498 | |
fad61490 TM |
499 | dreq->flags = 0; |
500 | switch (flags) { | |
501 | case NFS_ODIRECT_DO_COMMIT: | |
502 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 503 | break; |
fad61490 TM |
504 | case NFS_ODIRECT_RESCHED_WRITES: |
505 | nfs_direct_write_reschedule(dreq); | |
506 | break; | |
507 | default: | |
508 | nfs_end_data_update(inode); | |
509 | if (dreq->commit_data != NULL) | |
510 | nfs_commit_free(dreq->commit_data); | |
511 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 512 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
513 | nfs_direct_complete(dreq); |
514 | } | |
515 | } | |
1da177e4 | 516 | |
fad61490 TM |
517 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
518 | { | |
e9f7bee1 | 519 | dreq->commit_data = nfs_commit_alloc(); |
fad61490 TM |
520 | if (dreq->commit_data != NULL) |
521 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
522 | } | |
523 | #else | |
524 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
525 | { | |
526 | dreq->commit_data = NULL; | |
527 | } | |
1da177e4 | 528 | |
fad61490 TM |
529 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
530 | { | |
531 | nfs_end_data_update(inode); | |
532 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 533 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
534 | nfs_direct_complete(dreq); |
535 | } | |
536 | #endif | |
1da177e4 | 537 | |
462d5b32 | 538 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 539 | { |
462d5b32 CL |
540 | struct nfs_write_data *data = calldata; |
541 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
542 | int status = task->tk_status; | |
543 | ||
544 | if (nfs_writeback_done(task, data) != 0) | |
545 | return; | |
462d5b32 | 546 | |
15ce4a0c | 547 | spin_lock(&dreq->lock); |
1da177e4 | 548 | |
60fa3f76 TM |
549 | if (unlikely(dreq->error != 0)) |
550 | goto out_unlock; | |
eda3cef8 | 551 | if (unlikely(status < 0)) { |
60fa3f76 TM |
552 | /* An error has occured, so we should not commit */ |
553 | dreq->flags = 0; | |
eda3cef8 | 554 | dreq->error = status; |
eda3cef8 TM |
555 | } |
556 | ||
557 | dreq->count += data->res.count; | |
1da177e4 | 558 | |
fad61490 TM |
559 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
560 | switch (dreq->flags) { | |
561 | case 0: | |
562 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
563 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 564 | break; |
fad61490 TM |
565 | case NFS_ODIRECT_DO_COMMIT: |
566 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
567 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
568 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
569 | } | |
1da177e4 | 570 | } |
1da177e4 | 571 | } |
eda3cef8 | 572 | out_unlock: |
fad61490 | 573 | spin_unlock(&dreq->lock); |
1da177e4 LT |
574 | } |
575 | ||
fad61490 TM |
576 | /* |
577 | * NB: Return the value of the first error return code. Subsequent | |
578 | * errors after the first one are ignored. | |
1da177e4 | 579 | */ |
fad61490 | 580 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 581 | { |
fad61490 TM |
582 | struct nfs_write_data *data = calldata; |
583 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 584 | |
607f31e8 TM |
585 | if (put_dreq(dreq)) |
586 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
587 | } |
588 | ||
589 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
590 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 591 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
592 | }; |
593 | ||
594 | /* | |
607f31e8 TM |
595 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
596 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
597 | * bail and stop sending more writes. Write length accounting is | |
598 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
599 | * no requests have been sent, just return an error. | |
462d5b32 | 600 | */ |
607f31e8 | 601 | static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos, int sync) |
462d5b32 | 602 | { |
a8881f5a TM |
603 | struct nfs_open_context *ctx = dreq->ctx; |
604 | struct inode *inode = ctx->dentry->d_inode; | |
462d5b32 | 605 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
606 | unsigned int pgbase; |
607 | int result; | |
608 | ssize_t started = 0; | |
82b145c5 | 609 | |
607f31e8 TM |
610 | get_dreq(dreq); |
611 | ||
1da177e4 | 612 | do { |
82b145c5 | 613 | struct nfs_write_data *data; |
462d5b32 CL |
614 | size_t bytes; |
615 | ||
e9f7bee1 TM |
616 | pgbase = user_addr & ~PAGE_MASK; |
617 | bytes = min(wsize,count); | |
618 | ||
607f31e8 | 619 | result = -ENOMEM; |
8d5658c9 | 620 | data = nfs_writedata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
621 | if (unlikely(!data)) |
622 | break; | |
623 | ||
607f31e8 TM |
624 | down_read(¤t->mm->mmap_sem); |
625 | result = get_user_pages(current, current->mm, user_addr, | |
626 | data->npages, 0, 0, data->pagevec, NULL); | |
627 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
628 | if (result < 0) { |
629 | nfs_writedata_release(data); | |
630 | break; | |
631 | } | |
632 | if ((unsigned)result < data->npages) { | |
633 | nfs_direct_release_pages(data->pagevec, result); | |
607f31e8 TM |
634 | nfs_writedata_release(data); |
635 | break; | |
636 | } | |
637 | ||
638 | get_dreq(dreq); | |
639 | ||
fad61490 | 640 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 641 | |
607f31e8 | 642 | data->req = (struct nfs_page *) dreq; |
462d5b32 CL |
643 | data->inode = inode; |
644 | data->cred = ctx->cred; | |
645 | data->args.fh = NFS_FH(inode); | |
646 | data->args.context = ctx; | |
88467055 | 647 | data->args.offset = pos; |
462d5b32 | 648 | data->args.pgbase = pgbase; |
607f31e8 | 649 | data->args.pages = data->pagevec; |
462d5b32 CL |
650 | data->args.count = bytes; |
651 | data->res.fattr = &data->fattr; | |
652 | data->res.count = bytes; | |
47989d74 | 653 | data->res.verf = &data->verf; |
462d5b32 CL |
654 | |
655 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
656 | &nfs_write_direct_ops, data); | |
fad61490 | 657 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 658 | |
462d5b32 CL |
659 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
660 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 661 | |
462d5b32 | 662 | rpc_execute(&data->task); |
1da177e4 | 663 | |
a3f565b1 CL |
664 | dprintk("NFS: %5u initiated direct write call " |
665 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
462d5b32 CL |
666 | data->task.tk_pid, |
667 | inode->i_sb->s_id, | |
668 | (long long)NFS_FILEID(inode), | |
669 | bytes, | |
670 | (unsigned long long)data->args.offset); | |
1da177e4 | 671 | |
607f31e8 TM |
672 | started += bytes; |
673 | user_addr += bytes; | |
88467055 | 674 | pos += bytes; |
e9f7bee1 TM |
675 | |
676 | /* FIXME: Remove this useless math from the final patch */ | |
462d5b32 | 677 | pgbase += bytes; |
462d5b32 | 678 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 679 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 | 680 | |
462d5b32 CL |
681 | count -= bytes; |
682 | } while (count != 0); | |
607f31e8 TM |
683 | |
684 | if (put_dreq(dreq)) | |
685 | nfs_direct_write_complete(dreq, inode); | |
686 | ||
687 | if (started) | |
688 | return 0; | |
689 | return result < 0 ? (ssize_t) result : -EFAULT; | |
462d5b32 | 690 | } |
1da177e4 | 691 | |
607f31e8 | 692 | static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
462d5b32 | 693 | { |
607f31e8 | 694 | ssize_t result = 0; |
462d5b32 | 695 | sigset_t oldset; |
c89f2ee5 | 696 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
697 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
698 | struct nfs_direct_req *dreq; | |
fad61490 TM |
699 | size_t wsize = NFS_SERVER(inode)->wsize; |
700 | int sync = 0; | |
1da177e4 | 701 | |
607f31e8 | 702 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
703 | if (!dreq) |
704 | return -ENOMEM; | |
607f31e8 TM |
705 | nfs_alloc_commit_data(dreq); |
706 | ||
fad61490 TM |
707 | if (dreq->commit_data == NULL || count < wsize) |
708 | sync = FLUSH_STABLE; | |
1da177e4 | 709 | |
c89f2ee5 | 710 | dreq->inode = inode; |
a8881f5a | 711 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
c89f2ee5 CL |
712 | if (!is_sync_kiocb(iocb)) |
713 | dreq->iocb = iocb; | |
1da177e4 | 714 | |
47989d74 CL |
715 | nfs_add_stats(inode, NFSIOS_DIRECTWRITTENBYTES, count); |
716 | ||
462d5b32 | 717 | nfs_begin_data_update(inode); |
1da177e4 | 718 | |
462d5b32 | 719 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
720 | result = nfs_direct_write_schedule(dreq, user_addr, count, pos, sync); |
721 | if (!result) | |
722 | result = nfs_direct_wait(dreq); | |
462d5b32 | 723 | rpc_clnt_sigunmask(clnt, &oldset); |
b4946ffb | 724 | nfs_direct_req_release(dreq); |
1da177e4 | 725 | |
1da177e4 LT |
726 | return result; |
727 | } | |
728 | ||
729 | /** | |
730 | * nfs_file_direct_read - file direct read operation for NFS files | |
731 | * @iocb: target I/O control block | |
027445c3 BP |
732 | * @iov: vector of user buffers into which to read data |
733 | * @nr_segs: size of iov vector | |
88467055 | 734 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
735 | * |
736 | * We use this function for direct reads instead of calling | |
737 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
738 | * the request starts before the end of the file. For that check | |
739 | * to work, we must generate a GETATTR before each direct read, and | |
740 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 741 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
742 | * to do all reads the application wants, and the server will take |
743 | * care of managing the end of file boundary. | |
88467055 | 744 | * |
1da177e4 LT |
745 | * This function also eliminates unnecessarily updating the file's |
746 | * atime locally, as the NFS server sets the file's atime, and this | |
747 | * client must read the updated atime from the server back into its | |
748 | * cache. | |
749 | */ | |
027445c3 BP |
750 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
751 | unsigned long nr_segs, loff_t pos) | |
1da177e4 LT |
752 | { |
753 | ssize_t retval = -EINVAL; | |
1da177e4 | 754 | struct file *file = iocb->ki_filp; |
1da177e4 | 755 | struct address_space *mapping = file->f_mapping; |
027445c3 BP |
756 | /* XXX: temporary */ |
757 | const char __user *buf = iov[0].iov_base; | |
758 | size_t count = iov[0].iov_len; | |
1da177e4 | 759 | |
ce1a8e67 | 760 | dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n", |
01cce933 JJS |
761 | file->f_path.dentry->d_parent->d_name.name, |
762 | file->f_path.dentry->d_name.name, | |
ce1a8e67 | 763 | (unsigned long) count, (long long) pos); |
1da177e4 | 764 | |
027445c3 | 765 | if (nr_segs != 1) |
1da177e4 | 766 | goto out; |
070ea602 | 767 | |
1da177e4 | 768 | retval = -EFAULT; |
0cdd80d0 | 769 | if (!access_ok(VERIFY_WRITE, buf, count)) |
1da177e4 LT |
770 | goto out; |
771 | retval = 0; | |
772 | if (!count) | |
773 | goto out; | |
774 | ||
29884df0 TM |
775 | retval = nfs_sync_mapping(mapping); |
776 | if (retval) | |
777 | goto out; | |
1da177e4 | 778 | |
607f31e8 | 779 | retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos); |
1da177e4 | 780 | if (retval > 0) |
0cdd80d0 | 781 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
782 | |
783 | out: | |
784 | return retval; | |
785 | } | |
786 | ||
787 | /** | |
788 | * nfs_file_direct_write - file direct write operation for NFS files | |
789 | * @iocb: target I/O control block | |
027445c3 BP |
790 | * @iov: vector of user buffers from which to write data |
791 | * @nr_segs: size of iov vector | |
88467055 | 792 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
793 | * |
794 | * We use this function for direct writes instead of calling | |
795 | * generic_file_aio_write() in order to avoid taking the inode | |
796 | * semaphore and updating the i_size. The NFS server will set | |
797 | * the new i_size and this client must read the updated size | |
798 | * back into its cache. We let the server do generic write | |
799 | * parameter checking and report problems. | |
800 | * | |
801 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
802 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
803 | * | |
804 | * We eliminate local atime updates, see direct read above. | |
805 | * | |
806 | * We avoid unnecessary page cache invalidations for normal cached | |
807 | * readers of this file. | |
808 | * | |
809 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
810 | * is no atomic O_APPEND write facility in the NFS protocol. | |
811 | */ | |
027445c3 BP |
812 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
813 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 814 | { |
070ea602 | 815 | ssize_t retval = -EINVAL; |
1da177e4 | 816 | struct file *file = iocb->ki_filp; |
1da177e4 | 817 | struct address_space *mapping = file->f_mapping; |
027445c3 BP |
818 | /* XXX: temporary */ |
819 | const char __user *buf = iov[0].iov_base; | |
820 | size_t count = iov[0].iov_len; | |
1da177e4 | 821 | |
a3f565b1 | 822 | dprintk("nfs: direct write(%s/%s, %lu@%Ld)\n", |
01cce933 JJS |
823 | file->f_path.dentry->d_parent->d_name.name, |
824 | file->f_path.dentry->d_name.name, | |
ce1a8e67 | 825 | (unsigned long) count, (long long) pos); |
1da177e4 | 826 | |
027445c3 | 827 | if (nr_segs != 1) |
070ea602 | 828 | goto out; |
027445c3 | 829 | |
ce1a8e67 CL |
830 | retval = generic_write_checks(file, &pos, &count, 0); |
831 | if (retval) | |
1da177e4 | 832 | goto out; |
ce1a8e67 CL |
833 | |
834 | retval = -EINVAL; | |
835 | if ((ssize_t) count < 0) | |
1da177e4 | 836 | goto out; |
1da177e4 LT |
837 | retval = 0; |
838 | if (!count) | |
839 | goto out; | |
ce1a8e67 CL |
840 | |
841 | retval = -EFAULT; | |
47989d74 | 842 | if (!access_ok(VERIFY_READ, buf, count)) |
ce1a8e67 | 843 | goto out; |
1da177e4 | 844 | |
29884df0 TM |
845 | retval = nfs_sync_mapping(mapping); |
846 | if (retval) | |
847 | goto out; | |
1da177e4 | 848 | |
607f31e8 | 849 | retval = nfs_direct_write(iocb, (unsigned long) buf, count, pos); |
9eafa8cc | 850 | |
1da177e4 | 851 | if (retval > 0) |
ce1a8e67 | 852 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
853 | |
854 | out: | |
855 | return retval; | |
856 | } | |
857 | ||
88467055 CL |
858 | /** |
859 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
860 | * | |
861 | */ | |
f7b422b1 | 862 | int __init nfs_init_directcache(void) |
1da177e4 LT |
863 | { |
864 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
865 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
866 | 0, (SLAB_RECLAIM_ACCOUNT| |
867 | SLAB_MEM_SPREAD), | |
1da177e4 LT |
868 | NULL, NULL); |
869 | if (nfs_direct_cachep == NULL) | |
870 | return -ENOMEM; | |
871 | ||
872 | return 0; | |
873 | } | |
874 | ||
88467055 | 875 | /** |
f7b422b1 | 876 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
877 | * |
878 | */ | |
266bee88 | 879 | void nfs_destroy_directcache(void) |
1da177e4 | 880 | { |
1a1d92c1 | 881 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 882 | } |