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> | |
44 | #include <linux/smp_lock.h> | |
45 | #include <linux/file.h> | |
46 | #include <linux/pagemap.h> | |
47 | #include <linux/kref.h> | |
48 | ||
49 | #include <linux/nfs_fs.h> | |
50 | #include <linux/nfs_page.h> | |
51 | #include <linux/sunrpc/clnt.h> | |
52 | ||
53 | #include <asm/system.h> | |
54 | #include <asm/uaccess.h> | |
55 | #include <asm/atomic.h> | |
56 | ||
91d5b470 CL |
57 | #include "iostat.h" |
58 | ||
1da177e4 | 59 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 LT |
60 | |
61 | static kmem_cache_t *nfs_direct_cachep; | |
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 | ||
103 | /* | |
104 | * "size" is never larger than rsize or wsize. | |
105 | */ | |
106 | static inline int nfs_direct_count_pages(unsigned long user_addr, size_t size) | |
107 | { | |
108 | int page_count; | |
109 | ||
110 | page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
111 | page_count -= user_addr >> PAGE_SHIFT; | |
112 | BUG_ON(page_count < 0); | |
113 | ||
114 | return page_count; | |
115 | } | |
116 | ||
117 | static inline unsigned int nfs_max_pages(unsigned int size) | |
118 | { | |
119 | return (size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
120 | } | |
82b145c5 | 121 | |
1da177e4 | 122 | /** |
b8a32e2b CL |
123 | * nfs_direct_IO - NFS address space operation for direct I/O |
124 | * @rw: direction (read or write) | |
125 | * @iocb: target I/O control block | |
126 | * @iov: array of vectors that define I/O buffer | |
127 | * @pos: offset in file to begin the operation | |
128 | * @nr_segs: size of iovec array | |
129 | * | |
130 | * The presence of this routine in the address space ops vector means | |
131 | * the NFS client supports direct I/O. However, we shunt off direct | |
132 | * read and write requests before the VFS gets them, so this method | |
133 | * should never be called. | |
1da177e4 | 134 | */ |
b8a32e2b CL |
135 | ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) |
136 | { | |
b8a32e2b | 137 | dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", |
e99170ff TM |
138 | iocb->ki_filp->f_dentry->d_name.name, |
139 | (long long) pos, nr_segs); | |
b8a32e2b CL |
140 | |
141 | return -EINVAL; | |
142 | } | |
143 | ||
607f31e8 | 144 | static void nfs_direct_dirty_pages(struct page **pages, int npages) |
6b45d858 TM |
145 | { |
146 | int i; | |
147 | for (i = 0; i < npages; i++) { | |
148 | struct page *page = pages[i]; | |
607f31e8 | 149 | if (!PageCompound(page)) |
6b45d858 | 150 | set_page_dirty_lock(page); |
6b45d858 | 151 | } |
9c93ab7d CL |
152 | } |
153 | ||
607f31e8 | 154 | static void nfs_direct_release_pages(struct page **pages, int npages) |
9c93ab7d | 155 | { |
607f31e8 TM |
156 | int i; |
157 | for (i = 0; i < npages; i++) | |
158 | page_cache_release(pages[i]); | |
6b45d858 TM |
159 | } |
160 | ||
93619e59 | 161 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 162 | { |
93619e59 CL |
163 | struct nfs_direct_req *dreq; |
164 | ||
165 | dreq = kmem_cache_alloc(nfs_direct_cachep, SLAB_KERNEL); | |
166 | if (!dreq) | |
167 | return NULL; | |
168 | ||
169 | kref_init(&dreq->kref); | |
607f31e8 | 170 | kref_get(&dreq->kref); |
d72b7a6b | 171 | init_completion(&dreq->completion); |
fad61490 | 172 | INIT_LIST_HEAD(&dreq->rewrite_list); |
93619e59 | 173 | dreq->iocb = NULL; |
a8881f5a | 174 | dreq->ctx = NULL; |
15ce4a0c | 175 | spin_lock_init(&dreq->lock); |
607f31e8 | 176 | atomic_set(&dreq->io_count, 0); |
15ce4a0c CL |
177 | dreq->count = 0; |
178 | dreq->error = 0; | |
fad61490 | 179 | dreq->flags = 0; |
93619e59 CL |
180 | |
181 | return dreq; | |
1da177e4 LT |
182 | } |
183 | ||
1da177e4 LT |
184 | static void nfs_direct_req_release(struct kref *kref) |
185 | { | |
186 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a TM |
187 | |
188 | if (dreq->ctx != NULL) | |
189 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
190 | kmem_cache_free(nfs_direct_cachep, dreq); |
191 | } | |
192 | ||
bc0fb201 CL |
193 | /* |
194 | * Collects and returns the final error value/byte-count. | |
195 | */ | |
196 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
197 | { | |
15ce4a0c | 198 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
199 | |
200 | /* Async requests don't wait here */ | |
201 | if (dreq->iocb) | |
202 | goto out; | |
203 | ||
d72b7a6b | 204 | result = wait_for_completion_interruptible(&dreq->completion); |
bc0fb201 CL |
205 | |
206 | if (!result) | |
15ce4a0c | 207 | result = dreq->error; |
bc0fb201 | 208 | if (!result) |
15ce4a0c | 209 | result = dreq->count; |
bc0fb201 CL |
210 | |
211 | out: | |
212 | kref_put(&dreq->kref, nfs_direct_req_release); | |
213 | return (ssize_t) result; | |
214 | } | |
215 | ||
63ab46ab | 216 | /* |
607f31e8 TM |
217 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
218 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
219 | */ |
220 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
221 | { | |
63ab46ab | 222 | if (dreq->iocb) { |
15ce4a0c | 223 | long res = (long) dreq->error; |
63ab46ab | 224 | if (!res) |
15ce4a0c | 225 | res = (long) dreq->count; |
63ab46ab | 226 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
227 | } |
228 | complete_all(&dreq->completion); | |
63ab46ab CL |
229 | |
230 | kref_put(&dreq->kref, nfs_direct_req_release); | |
231 | } | |
232 | ||
06cf6f2e | 233 | /* |
607f31e8 TM |
234 | * We must hold a reference to all the pages in this direct read request |
235 | * until the RPCs complete. This could be long *after* we are woken up in | |
236 | * nfs_direct_wait (for instance, if someone hits ^C on a slow server). | |
06cf6f2e | 237 | */ |
ec06c096 | 238 | static void nfs_direct_read_result(struct rpc_task *task, void *calldata) |
1da177e4 | 239 | { |
ec06c096 | 240 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
241 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; |
242 | ||
ec06c096 TM |
243 | if (nfs_readpage_result(task, data) != 0) |
244 | return; | |
15ce4a0c | 245 | |
607f31e8 TM |
246 | nfs_direct_dirty_pages(data->pagevec, data->npages); |
247 | nfs_direct_release_pages(data->pagevec, data->npages); | |
248 | ||
15ce4a0c CL |
249 | spin_lock(&dreq->lock); |
250 | ||
ec06c096 | 251 | if (likely(task->tk_status >= 0)) |
15ce4a0c | 252 | dreq->count += data->res.count; |
1da177e4 | 253 | else |
15ce4a0c | 254 | dreq->error = task->tk_status; |
1da177e4 | 255 | |
ccf01ef7 | 256 | spin_unlock(&dreq->lock); |
607f31e8 TM |
257 | |
258 | if (put_dreq(dreq)) | |
259 | nfs_direct_complete(dreq); | |
1da177e4 LT |
260 | } |
261 | ||
ec06c096 TM |
262 | static const struct rpc_call_ops nfs_read_direct_ops = { |
263 | .rpc_call_done = nfs_direct_read_result, | |
264 | .rpc_release = nfs_readdata_release, | |
265 | }; | |
266 | ||
d4cc948b | 267 | /* |
607f31e8 TM |
268 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
269 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
270 | * bail and stop sending more reads. Read length accounting is | |
271 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
272 | * no requests have been sent, just return an error. | |
1da177e4 | 273 | */ |
607f31e8 | 274 | static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 275 | { |
a8881f5a TM |
276 | struct nfs_open_context *ctx = dreq->ctx; |
277 | struct inode *inode = ctx->dentry->d_inode; | |
5dd602f2 | 278 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
279 | unsigned int rpages = nfs_max_pages(rsize); |
280 | unsigned int pgbase; | |
281 | int result; | |
282 | ssize_t started = 0; | |
283 | ||
284 | get_dreq(dreq); | |
1da177e4 | 285 | |
607f31e8 | 286 | pgbase = user_addr & ~PAGE_MASK; |
1da177e4 | 287 | do { |
82b145c5 | 288 | struct nfs_read_data *data; |
5dd602f2 | 289 | size_t bytes; |
1da177e4 | 290 | |
607f31e8 TM |
291 | result = -ENOMEM; |
292 | data = nfs_readdata_alloc(rpages); | |
293 | if (unlikely(!data)) | |
294 | break; | |
295 | ||
1da177e4 LT |
296 | bytes = rsize; |
297 | if (count < rsize) | |
298 | bytes = count; | |
299 | ||
607f31e8 TM |
300 | data->npages = nfs_direct_count_pages(user_addr, bytes); |
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); | |
305 | if (unlikely(result < data->npages)) { | |
306 | if (result > 0) | |
307 | nfs_direct_release_pages(data->pagevec, result); | |
308 | nfs_readdata_release(data); | |
309 | break; | |
310 | } | |
311 | ||
312 | get_dreq(dreq); | |
82b145c5 | 313 | |
607f31e8 | 314 | data->req = (struct nfs_page *) dreq; |
1da177e4 LT |
315 | data->inode = inode; |
316 | data->cred = ctx->cred; | |
317 | data->args.fh = NFS_FH(inode); | |
318 | data->args.context = ctx; | |
88467055 | 319 | data->args.offset = pos; |
1da177e4 | 320 | data->args.pgbase = pgbase; |
607f31e8 | 321 | data->args.pages = data->pagevec; |
1da177e4 LT |
322 | data->args.count = bytes; |
323 | data->res.fattr = &data->fattr; | |
324 | data->res.eof = 0; | |
325 | data->res.count = bytes; | |
326 | ||
ec06c096 TM |
327 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
328 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
329 | NFS_PROTO(inode)->read_setup(data); |
330 | ||
331 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
332 | |
333 | lock_kernel(); | |
334 | rpc_execute(&data->task); | |
335 | unlock_kernel(); | |
336 | ||
606bbba0 | 337 | dfprintk(VFS, "NFS: %5u initiated direct read call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
1da177e4 LT |
338 | data->task.tk_pid, |
339 | inode->i_sb->s_id, | |
340 | (long long)NFS_FILEID(inode), | |
341 | bytes, | |
342 | (unsigned long long)data->args.offset); | |
343 | ||
607f31e8 TM |
344 | started += bytes; |
345 | user_addr += bytes; | |
88467055 | 346 | pos += bytes; |
1da177e4 | 347 | pgbase += bytes; |
1da177e4 LT |
348 | pgbase &= ~PAGE_MASK; |
349 | ||
350 | count -= bytes; | |
351 | } while (count != 0); | |
607f31e8 TM |
352 | |
353 | if (put_dreq(dreq)) | |
354 | nfs_direct_complete(dreq); | |
355 | ||
356 | if (started) | |
357 | return 0; | |
358 | return result < 0 ? (ssize_t) result : -EFAULT; | |
1da177e4 LT |
359 | } |
360 | ||
607f31e8 | 361 | static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 362 | { |
607f31e8 | 363 | ssize_t result = 0; |
1da177e4 | 364 | sigset_t oldset; |
99514f8f | 365 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
366 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
367 | struct nfs_direct_req *dreq; | |
368 | ||
607f31e8 | 369 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
370 | if (!dreq) |
371 | return -ENOMEM; | |
372 | ||
91d5b470 | 373 | dreq->inode = inode; |
a8881f5a | 374 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
487b8372 CL |
375 | if (!is_sync_kiocb(iocb)) |
376 | dreq->iocb = iocb; | |
1da177e4 | 377 | |
91d5b470 | 378 | nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); |
1da177e4 | 379 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
380 | result = nfs_direct_read_schedule(dreq, user_addr, count, pos); |
381 | if (!result) | |
382 | result = nfs_direct_wait(dreq); | |
1da177e4 LT |
383 | rpc_clnt_sigunmask(clnt, &oldset); |
384 | ||
385 | return result; | |
386 | } | |
387 | ||
fad61490 | 388 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 389 | { |
607f31e8 TM |
390 | while (!list_empty(&dreq->rewrite_list)) { |
391 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 392 | list_del(&data->pages); |
607f31e8 | 393 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
394 | nfs_writedata_release(data); |
395 | } | |
396 | } | |
1da177e4 | 397 | |
fad61490 TM |
398 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
399 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
400 | { | |
607f31e8 TM |
401 | struct inode *inode = dreq->inode; |
402 | struct list_head *p; | |
403 | struct nfs_write_data *data; | |
1da177e4 | 404 | |
fad61490 | 405 | dreq->count = 0; |
607f31e8 TM |
406 | get_dreq(dreq); |
407 | ||
408 | list_for_each(p, &dreq->rewrite_list) { | |
409 | data = list_entry(p, struct nfs_write_data, pages); | |
410 | ||
411 | get_dreq(dreq); | |
412 | ||
413 | /* | |
414 | * Reset data->res. | |
415 | */ | |
416 | nfs_fattr_init(&data->fattr); | |
417 | data->res.count = data->args.count; | |
418 | memset(&data->verf, 0, sizeof(data->verf)); | |
419 | ||
420 | /* | |
421 | * Reuse data->task; data->args should not have changed | |
422 | * since the original request was sent. | |
423 | */ | |
424 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
425 | &nfs_write_direct_ops, data); | |
426 | NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); | |
427 | ||
428 | data->task.tk_priority = RPC_PRIORITY_NORMAL; | |
429 | data->task.tk_cookie = (unsigned long) inode; | |
430 | ||
431 | /* | |
432 | * We're called via an RPC callback, so BKL is already held. | |
433 | */ | |
434 | rpc_execute(&data->task); | |
435 | ||
436 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
437 | data->task.tk_pid, | |
438 | inode->i_sb->s_id, | |
439 | (long long)NFS_FILEID(inode), | |
440 | data->args.count, | |
441 | (unsigned long long)data->args.offset); | |
442 | } | |
fedb595c | 443 | |
607f31e8 TM |
444 | if (put_dreq(dreq)) |
445 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
446 | } |
447 | ||
448 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
449 | { | |
450 | struct nfs_write_data *data = calldata; | |
451 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
452 | ||
453 | /* Call the NFS version-specific code */ | |
454 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
455 | return; | |
456 | if (unlikely(task->tk_status < 0)) { | |
457 | dreq->error = task->tk_status; | |
458 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
459 | } | |
460 | if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { | |
461 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); | |
462 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
463 | } |
464 | ||
fad61490 TM |
465 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
466 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
467 | } |
468 | ||
fad61490 TM |
469 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
470 | .rpc_call_done = nfs_direct_commit_result, | |
471 | .rpc_release = nfs_commit_release, | |
472 | }; | |
473 | ||
474 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 475 | { |
fad61490 | 476 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 477 | |
fad61490 | 478 | data->inode = dreq->inode; |
a8881f5a | 479 | data->cred = dreq->ctx->cred; |
1da177e4 | 480 | |
fad61490 | 481 | data->args.fh = NFS_FH(data->inode); |
607f31e8 TM |
482 | data->args.offset = 0; |
483 | data->args.count = 0; | |
fad61490 TM |
484 | data->res.count = 0; |
485 | data->res.fattr = &data->fattr; | |
486 | data->res.verf = &data->verf; | |
1da177e4 | 487 | |
fad61490 TM |
488 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
489 | &nfs_commit_direct_ops, data); | |
490 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 491 | |
fad61490 TM |
492 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
493 | data->task.tk_cookie = (unsigned long)data->inode; | |
494 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
495 | dreq->commit_data = NULL; | |
1da177e4 | 496 | |
e99170ff | 497 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 498 | |
fad61490 TM |
499 | lock_kernel(); |
500 | rpc_execute(&data->task); | |
501 | unlock_kernel(); | |
502 | } | |
1da177e4 | 503 | |
fad61490 TM |
504 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
505 | { | |
506 | int flags = dreq->flags; | |
1da177e4 | 507 | |
fad61490 TM |
508 | dreq->flags = 0; |
509 | switch (flags) { | |
510 | case NFS_ODIRECT_DO_COMMIT: | |
511 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 512 | break; |
fad61490 TM |
513 | case NFS_ODIRECT_RESCHED_WRITES: |
514 | nfs_direct_write_reschedule(dreq); | |
515 | break; | |
516 | default: | |
517 | nfs_end_data_update(inode); | |
518 | if (dreq->commit_data != NULL) | |
519 | nfs_commit_free(dreq->commit_data); | |
520 | nfs_direct_free_writedata(dreq); | |
521 | nfs_direct_complete(dreq); | |
522 | } | |
523 | } | |
1da177e4 | 524 | |
fad61490 TM |
525 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
526 | { | |
527 | dreq->commit_data = nfs_commit_alloc(0); | |
528 | if (dreq->commit_data != NULL) | |
529 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
530 | } | |
531 | #else | |
532 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
533 | { | |
534 | dreq->commit_data = NULL; | |
535 | } | |
1da177e4 | 536 | |
fad61490 TM |
537 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
538 | { | |
539 | nfs_end_data_update(inode); | |
540 | nfs_direct_free_writedata(dreq); | |
541 | nfs_direct_complete(dreq); | |
542 | } | |
543 | #endif | |
1da177e4 | 544 | |
462d5b32 | 545 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 546 | { |
462d5b32 CL |
547 | struct nfs_write_data *data = calldata; |
548 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
549 | int status = task->tk_status; | |
550 | ||
551 | if (nfs_writeback_done(task, data) != 0) | |
552 | return; | |
462d5b32 | 553 | |
15ce4a0c | 554 | spin_lock(&dreq->lock); |
1da177e4 | 555 | |
462d5b32 | 556 | if (likely(status >= 0)) |
15ce4a0c | 557 | dreq->count += data->res.count; |
462d5b32 | 558 | else |
fad61490 | 559 | dreq->error = task->tk_status; |
1da177e4 | 560 | |
fad61490 TM |
561 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
562 | switch (dreq->flags) { | |
563 | case 0: | |
564 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
565 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 566 | break; |
fad61490 TM |
567 | case NFS_ODIRECT_DO_COMMIT: |
568 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
569 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
570 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
571 | } | |
1da177e4 | 572 | } |
1da177e4 | 573 | } |
fad61490 TM |
574 | |
575 | spin_unlock(&dreq->lock); | |
1da177e4 LT |
576 | } |
577 | ||
fad61490 TM |
578 | /* |
579 | * NB: Return the value of the first error return code. Subsequent | |
580 | * errors after the first one are ignored. | |
1da177e4 | 581 | */ |
fad61490 | 582 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 583 | { |
fad61490 TM |
584 | struct nfs_write_data *data = calldata; |
585 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 586 | |
607f31e8 TM |
587 | if (put_dreq(dreq)) |
588 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
589 | } |
590 | ||
591 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
592 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 593 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
594 | }; |
595 | ||
596 | /* | |
607f31e8 TM |
597 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
598 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
599 | * bail and stop sending more writes. Write length accounting is | |
600 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
601 | * no requests have been sent, just return an error. | |
462d5b32 | 602 | */ |
607f31e8 | 603 | 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 | 604 | { |
a8881f5a TM |
605 | struct nfs_open_context *ctx = dreq->ctx; |
606 | struct inode *inode = ctx->dentry->d_inode; | |
462d5b32 | 607 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
608 | unsigned int wpages = nfs_max_pages(wsize); |
609 | unsigned int pgbase; | |
610 | int result; | |
611 | ssize_t started = 0; | |
82b145c5 | 612 | |
607f31e8 TM |
613 | get_dreq(dreq); |
614 | ||
615 | pgbase = user_addr & ~PAGE_MASK; | |
1da177e4 | 616 | do { |
82b145c5 | 617 | struct nfs_write_data *data; |
462d5b32 CL |
618 | size_t bytes; |
619 | ||
607f31e8 TM |
620 | result = -ENOMEM; |
621 | data = nfs_writedata_alloc(wpages); | |
622 | if (unlikely(!data)) | |
623 | break; | |
624 | ||
462d5b32 CL |
625 | bytes = wsize; |
626 | if (count < wsize) | |
627 | bytes = count; | |
628 | ||
607f31e8 TM |
629 | data->npages = nfs_direct_count_pages(user_addr, bytes); |
630 | down_read(¤t->mm->mmap_sem); | |
631 | result = get_user_pages(current, current->mm, user_addr, | |
632 | data->npages, 0, 0, data->pagevec, NULL); | |
633 | up_read(¤t->mm->mmap_sem); | |
634 | if (unlikely(result < data->npages)) { | |
635 | if (result > 0) | |
636 | nfs_direct_release_pages(data->pagevec, result); | |
637 | nfs_writedata_release(data); | |
638 | break; | |
639 | } | |
640 | ||
641 | get_dreq(dreq); | |
642 | ||
fad61490 | 643 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 644 | |
607f31e8 | 645 | data->req = (struct nfs_page *) dreq; |
462d5b32 CL |
646 | data->inode = inode; |
647 | data->cred = ctx->cred; | |
648 | data->args.fh = NFS_FH(inode); | |
649 | data->args.context = ctx; | |
88467055 | 650 | data->args.offset = pos; |
462d5b32 | 651 | data->args.pgbase = pgbase; |
607f31e8 | 652 | data->args.pages = data->pagevec; |
462d5b32 CL |
653 | data->args.count = bytes; |
654 | data->res.fattr = &data->fattr; | |
655 | data->res.count = bytes; | |
47989d74 | 656 | data->res.verf = &data->verf; |
462d5b32 CL |
657 | |
658 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
659 | &nfs_write_direct_ops, data); | |
fad61490 | 660 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 661 | |
462d5b32 CL |
662 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
663 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
664 | |
665 | lock_kernel(); | |
462d5b32 | 666 | rpc_execute(&data->task); |
1da177e4 LT |
667 | unlock_kernel(); |
668 | ||
606bbba0 | 669 | dfprintk(VFS, "NFS: %5u initiated direct write call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
462d5b32 CL |
670 | data->task.tk_pid, |
671 | inode->i_sb->s_id, | |
672 | (long long)NFS_FILEID(inode), | |
673 | bytes, | |
674 | (unsigned long long)data->args.offset); | |
1da177e4 | 675 | |
607f31e8 TM |
676 | started += bytes; |
677 | user_addr += bytes; | |
88467055 | 678 | pos += bytes; |
462d5b32 | 679 | pgbase += bytes; |
462d5b32 | 680 | pgbase &= ~PAGE_MASK; |
1da177e4 | 681 | |
462d5b32 CL |
682 | count -= bytes; |
683 | } while (count != 0); | |
607f31e8 TM |
684 | |
685 | if (put_dreq(dreq)) | |
686 | nfs_direct_write_complete(dreq, inode); | |
687 | ||
688 | if (started) | |
689 | return 0; | |
690 | return result < 0 ? (ssize_t) result : -EFAULT; | |
462d5b32 | 691 | } |
1da177e4 | 692 | |
607f31e8 | 693 | static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
462d5b32 | 694 | { |
607f31e8 | 695 | ssize_t result = 0; |
462d5b32 | 696 | sigset_t oldset; |
c89f2ee5 | 697 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
698 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
699 | struct nfs_direct_req *dreq; | |
fad61490 TM |
700 | size_t wsize = NFS_SERVER(inode)->wsize; |
701 | int sync = 0; | |
1da177e4 | 702 | |
607f31e8 | 703 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
704 | if (!dreq) |
705 | return -ENOMEM; | |
607f31e8 TM |
706 | nfs_alloc_commit_data(dreq); |
707 | ||
fad61490 TM |
708 | if (dreq->commit_data == NULL || count < wsize) |
709 | sync = FLUSH_STABLE; | |
1da177e4 | 710 | |
c89f2ee5 | 711 | dreq->inode = inode; |
a8881f5a | 712 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
c89f2ee5 CL |
713 | if (!is_sync_kiocb(iocb)) |
714 | dreq->iocb = iocb; | |
1da177e4 | 715 | |
47989d74 CL |
716 | nfs_add_stats(inode, NFSIOS_DIRECTWRITTENBYTES, count); |
717 | ||
462d5b32 | 718 | nfs_begin_data_update(inode); |
1da177e4 | 719 | |
462d5b32 | 720 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
721 | result = nfs_direct_write_schedule(dreq, user_addr, count, pos, sync); |
722 | if (!result) | |
723 | result = nfs_direct_wait(dreq); | |
462d5b32 | 724 | rpc_clnt_sigunmask(clnt, &oldset); |
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 | |
732 | * @buf: user's buffer into which to read data | |
88467055 CL |
733 | * @count: number of bytes to read |
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 | */ | |
d4cc948b | 750 | ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos) |
1da177e4 LT |
751 | { |
752 | ssize_t retval = -EINVAL; | |
1da177e4 | 753 | struct file *file = iocb->ki_filp; |
1da177e4 | 754 | struct address_space *mapping = file->f_mapping; |
1da177e4 | 755 | |
ce1a8e67 | 756 | dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n", |
0bbacc40 CL |
757 | file->f_dentry->d_parent->d_name.name, |
758 | file->f_dentry->d_name.name, | |
ce1a8e67 | 759 | (unsigned long) count, (long long) pos); |
1da177e4 | 760 | |
1da177e4 LT |
761 | if (count < 0) |
762 | goto out; | |
763 | retval = -EFAULT; | |
0cdd80d0 | 764 | if (!access_ok(VERIFY_WRITE, buf, count)) |
1da177e4 LT |
765 | goto out; |
766 | retval = 0; | |
767 | if (!count) | |
768 | goto out; | |
769 | ||
29884df0 TM |
770 | retval = nfs_sync_mapping(mapping); |
771 | if (retval) | |
772 | goto out; | |
1da177e4 | 773 | |
607f31e8 | 774 | retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos); |
1da177e4 | 775 | if (retval > 0) |
0cdd80d0 | 776 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
777 | |
778 | out: | |
779 | return retval; | |
780 | } | |
781 | ||
782 | /** | |
783 | * nfs_file_direct_write - file direct write operation for NFS files | |
784 | * @iocb: target I/O control block | |
785 | * @buf: user's buffer from which to write data | |
88467055 CL |
786 | * @count: number of bytes to write |
787 | * @pos: byte offset in file where writing starts | |
1da177e4 LT |
788 | * |
789 | * We use this function for direct writes instead of calling | |
790 | * generic_file_aio_write() in order to avoid taking the inode | |
791 | * semaphore and updating the i_size. The NFS server will set | |
792 | * the new i_size and this client must read the updated size | |
793 | * back into its cache. We let the server do generic write | |
794 | * parameter checking and report problems. | |
795 | * | |
796 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
797 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
798 | * | |
799 | * We eliminate local atime updates, see direct read above. | |
800 | * | |
801 | * We avoid unnecessary page cache invalidations for normal cached | |
802 | * readers of this file. | |
803 | * | |
804 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
805 | * is no atomic O_APPEND write facility in the NFS protocol. | |
806 | */ | |
d4cc948b | 807 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos) |
1da177e4 | 808 | { |
ce1a8e67 | 809 | ssize_t retval; |
1da177e4 | 810 | struct file *file = iocb->ki_filp; |
1da177e4 | 811 | struct address_space *mapping = file->f_mapping; |
1da177e4 | 812 | |
ce1a8e67 | 813 | dfprintk(VFS, "nfs: direct write(%s/%s, %lu@%Ld)\n", |
0bbacc40 | 814 | file->f_dentry->d_parent->d_name.name, |
ce1a8e67 CL |
815 | file->f_dentry->d_name.name, |
816 | (unsigned long) count, (long long) pos); | |
1da177e4 | 817 | |
ce1a8e67 CL |
818 | retval = generic_write_checks(file, &pos, &count, 0); |
819 | if (retval) | |
1da177e4 | 820 | goto out; |
ce1a8e67 CL |
821 | |
822 | retval = -EINVAL; | |
823 | if ((ssize_t) count < 0) | |
1da177e4 | 824 | goto out; |
1da177e4 LT |
825 | retval = 0; |
826 | if (!count) | |
827 | goto out; | |
ce1a8e67 CL |
828 | |
829 | retval = -EFAULT; | |
47989d74 | 830 | if (!access_ok(VERIFY_READ, buf, count)) |
ce1a8e67 | 831 | goto out; |
1da177e4 | 832 | |
29884df0 TM |
833 | retval = nfs_sync_mapping(mapping); |
834 | if (retval) | |
835 | goto out; | |
1da177e4 | 836 | |
607f31e8 | 837 | retval = nfs_direct_write(iocb, (unsigned long) buf, count, pos); |
9eafa8cc CL |
838 | |
839 | /* | |
840 | * XXX: nfs_end_data_update() already ensures this file's | |
841 | * cached data is subsequently invalidated. Do we really | |
842 | * need to call invalidate_inode_pages2() again here? | |
843 | * | |
844 | * For aio writes, this invalidation will almost certainly | |
845 | * occur before the writes complete. Kind of racey. | |
846 | */ | |
1da177e4 LT |
847 | if (mapping->nrpages) |
848 | invalidate_inode_pages2(mapping); | |
9eafa8cc | 849 | |
1da177e4 | 850 | if (retval > 0) |
ce1a8e67 | 851 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
852 | |
853 | out: | |
854 | return retval; | |
855 | } | |
856 | ||
88467055 CL |
857 | /** |
858 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
859 | * | |
860 | */ | |
f7b422b1 | 861 | int __init nfs_init_directcache(void) |
1da177e4 LT |
862 | { |
863 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
864 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
865 | 0, (SLAB_RECLAIM_ACCOUNT| |
866 | SLAB_MEM_SPREAD), | |
1da177e4 LT |
867 | NULL, NULL); |
868 | if (nfs_direct_cachep == NULL) | |
869 | return -ENOMEM; | |
870 | ||
871 | return 0; | |
872 | } | |
873 | ||
88467055 | 874 | /** |
f7b422b1 | 875 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
876 | * |
877 | */ | |
266bee88 | 878 | void nfs_destroy_directcache(void) |
1da177e4 LT |
879 | { |
880 | if (kmem_cache_destroy(nfs_direct_cachep)) | |
881 | printk(KERN_INFO "nfs_direct_cache: not all structures were freed\n"); | |
882 | } |