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 | ||
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", |
e99170ff TM |
119 | iocb->ki_filp->f_dentry->d_name.name, |
120 | (long long) pos, nr_segs); | |
b8a32e2b CL |
121 | |
122 | return -EINVAL; | |
123 | } | |
124 | ||
607f31e8 | 125 | static void nfs_direct_dirty_pages(struct page **pages, int npages) |
6b45d858 TM |
126 | { |
127 | int i; | |
128 | for (i = 0; i < npages; i++) { | |
129 | struct page *page = pages[i]; | |
607f31e8 | 130 | if (!PageCompound(page)) |
6b45d858 | 131 | set_page_dirty_lock(page); |
6b45d858 | 132 | } |
9c93ab7d CL |
133 | } |
134 | ||
607f31e8 | 135 | static void nfs_direct_release_pages(struct page **pages, int npages) |
9c93ab7d | 136 | { |
607f31e8 TM |
137 | int i; |
138 | for (i = 0; i < npages; i++) | |
139 | page_cache_release(pages[i]); | |
6b45d858 TM |
140 | } |
141 | ||
93619e59 | 142 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 143 | { |
93619e59 CL |
144 | struct nfs_direct_req *dreq; |
145 | ||
e94b1766 | 146 | dreq = kmem_cache_alloc(nfs_direct_cachep, GFP_KERNEL); |
93619e59 CL |
147 | if (!dreq) |
148 | return NULL; | |
149 | ||
150 | kref_init(&dreq->kref); | |
607f31e8 | 151 | kref_get(&dreq->kref); |
d72b7a6b | 152 | init_completion(&dreq->completion); |
fad61490 | 153 | INIT_LIST_HEAD(&dreq->rewrite_list); |
93619e59 | 154 | dreq->iocb = NULL; |
a8881f5a | 155 | dreq->ctx = NULL; |
15ce4a0c | 156 | spin_lock_init(&dreq->lock); |
607f31e8 | 157 | atomic_set(&dreq->io_count, 0); |
15ce4a0c CL |
158 | dreq->count = 0; |
159 | dreq->error = 0; | |
fad61490 | 160 | dreq->flags = 0; |
93619e59 CL |
161 | |
162 | return dreq; | |
1da177e4 LT |
163 | } |
164 | ||
1da177e4 LT |
165 | static void nfs_direct_req_release(struct kref *kref) |
166 | { | |
167 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a TM |
168 | |
169 | if (dreq->ctx != NULL) | |
170 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
171 | kmem_cache_free(nfs_direct_cachep, dreq); |
172 | } | |
173 | ||
bc0fb201 CL |
174 | /* |
175 | * Collects and returns the final error value/byte-count. | |
176 | */ | |
177 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
178 | { | |
15ce4a0c | 179 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
180 | |
181 | /* Async requests don't wait here */ | |
182 | if (dreq->iocb) | |
183 | goto out; | |
184 | ||
d72b7a6b | 185 | result = wait_for_completion_interruptible(&dreq->completion); |
bc0fb201 CL |
186 | |
187 | if (!result) | |
15ce4a0c | 188 | result = dreq->error; |
bc0fb201 | 189 | if (!result) |
15ce4a0c | 190 | result = dreq->count; |
bc0fb201 CL |
191 | |
192 | out: | |
193 | kref_put(&dreq->kref, nfs_direct_req_release); | |
194 | return (ssize_t) result; | |
195 | } | |
196 | ||
63ab46ab | 197 | /* |
607f31e8 TM |
198 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
199 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
200 | */ |
201 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
202 | { | |
63ab46ab | 203 | if (dreq->iocb) { |
15ce4a0c | 204 | long res = (long) dreq->error; |
63ab46ab | 205 | if (!res) |
15ce4a0c | 206 | res = (long) dreq->count; |
63ab46ab | 207 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
208 | } |
209 | complete_all(&dreq->completion); | |
63ab46ab CL |
210 | |
211 | kref_put(&dreq->kref, nfs_direct_req_release); | |
212 | } | |
213 | ||
06cf6f2e | 214 | /* |
607f31e8 TM |
215 | * We must hold a reference to all the pages in this direct read request |
216 | * until the RPCs complete. This could be long *after* we are woken up in | |
217 | * nfs_direct_wait (for instance, if someone hits ^C on a slow server). | |
06cf6f2e | 218 | */ |
ec06c096 | 219 | static void nfs_direct_read_result(struct rpc_task *task, void *calldata) |
1da177e4 | 220 | { |
ec06c096 | 221 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
222 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; |
223 | ||
ec06c096 TM |
224 | if (nfs_readpage_result(task, data) != 0) |
225 | return; | |
15ce4a0c | 226 | |
607f31e8 TM |
227 | nfs_direct_dirty_pages(data->pagevec, data->npages); |
228 | nfs_direct_release_pages(data->pagevec, data->npages); | |
229 | ||
15ce4a0c CL |
230 | spin_lock(&dreq->lock); |
231 | ||
ec06c096 | 232 | if (likely(task->tk_status >= 0)) |
15ce4a0c | 233 | dreq->count += data->res.count; |
1da177e4 | 234 | else |
15ce4a0c | 235 | dreq->error = task->tk_status; |
1da177e4 | 236 | |
ccf01ef7 | 237 | spin_unlock(&dreq->lock); |
607f31e8 TM |
238 | |
239 | if (put_dreq(dreq)) | |
240 | nfs_direct_complete(dreq); | |
1da177e4 LT |
241 | } |
242 | ||
ec06c096 TM |
243 | static const struct rpc_call_ops nfs_read_direct_ops = { |
244 | .rpc_call_done = nfs_direct_read_result, | |
245 | .rpc_release = nfs_readdata_release, | |
246 | }; | |
247 | ||
d4cc948b | 248 | /* |
607f31e8 TM |
249 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
250 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
251 | * bail and stop sending more reads. Read length accounting is | |
252 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
253 | * no requests have been sent, just return an error. | |
1da177e4 | 254 | */ |
607f31e8 | 255 | static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 256 | { |
a8881f5a TM |
257 | struct nfs_open_context *ctx = dreq->ctx; |
258 | struct inode *inode = ctx->dentry->d_inode; | |
5dd602f2 | 259 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
260 | unsigned int pgbase; |
261 | int result; | |
262 | ssize_t started = 0; | |
263 | ||
264 | get_dreq(dreq); | |
1da177e4 | 265 | |
1da177e4 | 266 | do { |
82b145c5 | 267 | struct nfs_read_data *data; |
5dd602f2 | 268 | size_t bytes; |
1da177e4 | 269 | |
e9f7bee1 TM |
270 | pgbase = user_addr & ~PAGE_MASK; |
271 | bytes = min(rsize,count); | |
272 | ||
607f31e8 | 273 | result = -ENOMEM; |
e9f7bee1 | 274 | data = nfs_readdata_alloc(pgbase + bytes); |
607f31e8 TM |
275 | if (unlikely(!data)) |
276 | break; | |
277 | ||
607f31e8 TM |
278 | down_read(¤t->mm->mmap_sem); |
279 | result = get_user_pages(current, current->mm, user_addr, | |
280 | data->npages, 1, 0, data->pagevec, NULL); | |
281 | up_read(¤t->mm->mmap_sem); | |
282 | if (unlikely(result < data->npages)) { | |
283 | if (result > 0) | |
284 | nfs_direct_release_pages(data->pagevec, result); | |
285 | nfs_readdata_release(data); | |
286 | break; | |
287 | } | |
288 | ||
289 | get_dreq(dreq); | |
82b145c5 | 290 | |
607f31e8 | 291 | data->req = (struct nfs_page *) dreq; |
1da177e4 LT |
292 | data->inode = inode; |
293 | data->cred = ctx->cred; | |
294 | data->args.fh = NFS_FH(inode); | |
295 | data->args.context = ctx; | |
88467055 | 296 | data->args.offset = pos; |
1da177e4 | 297 | data->args.pgbase = pgbase; |
607f31e8 | 298 | data->args.pages = data->pagevec; |
1da177e4 LT |
299 | data->args.count = bytes; |
300 | data->res.fattr = &data->fattr; | |
301 | data->res.eof = 0; | |
302 | data->res.count = bytes; | |
303 | ||
ec06c096 TM |
304 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
305 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
306 | NFS_PROTO(inode)->read_setup(data); |
307 | ||
308 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
309 | |
310 | lock_kernel(); | |
311 | rpc_execute(&data->task); | |
312 | unlock_kernel(); | |
313 | ||
606bbba0 | 314 | dfprintk(VFS, "NFS: %5u initiated direct read call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
1da177e4 LT |
315 | data->task.tk_pid, |
316 | inode->i_sb->s_id, | |
317 | (long long)NFS_FILEID(inode), | |
318 | bytes, | |
319 | (unsigned long long)data->args.offset); | |
320 | ||
607f31e8 TM |
321 | started += bytes; |
322 | user_addr += bytes; | |
88467055 | 323 | pos += bytes; |
e9f7bee1 | 324 | /* FIXME: Remove this unnecessary math from final patch */ |
1da177e4 | 325 | pgbase += bytes; |
1da177e4 | 326 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 327 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 LT |
328 | |
329 | count -= bytes; | |
330 | } while (count != 0); | |
607f31e8 TM |
331 | |
332 | if (put_dreq(dreq)) | |
333 | nfs_direct_complete(dreq); | |
334 | ||
335 | if (started) | |
336 | return 0; | |
337 | return result < 0 ? (ssize_t) result : -EFAULT; | |
1da177e4 LT |
338 | } |
339 | ||
607f31e8 | 340 | static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 341 | { |
607f31e8 | 342 | ssize_t result = 0; |
1da177e4 | 343 | sigset_t oldset; |
99514f8f | 344 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
345 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
346 | struct nfs_direct_req *dreq; | |
347 | ||
607f31e8 | 348 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
349 | if (!dreq) |
350 | return -ENOMEM; | |
351 | ||
91d5b470 | 352 | dreq->inode = inode; |
a8881f5a | 353 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
487b8372 CL |
354 | if (!is_sync_kiocb(iocb)) |
355 | dreq->iocb = iocb; | |
1da177e4 | 356 | |
91d5b470 | 357 | nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); |
1da177e4 | 358 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
359 | result = nfs_direct_read_schedule(dreq, user_addr, count, pos); |
360 | if (!result) | |
361 | result = nfs_direct_wait(dreq); | |
1da177e4 LT |
362 | rpc_clnt_sigunmask(clnt, &oldset); |
363 | ||
364 | return result; | |
365 | } | |
366 | ||
fad61490 | 367 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 368 | { |
607f31e8 TM |
369 | while (!list_empty(&dreq->rewrite_list)) { |
370 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 371 | list_del(&data->pages); |
607f31e8 | 372 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
373 | nfs_writedata_release(data); |
374 | } | |
375 | } | |
1da177e4 | 376 | |
fad61490 TM |
377 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
378 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
379 | { | |
607f31e8 TM |
380 | struct inode *inode = dreq->inode; |
381 | struct list_head *p; | |
382 | struct nfs_write_data *data; | |
1da177e4 | 383 | |
fad61490 | 384 | dreq->count = 0; |
607f31e8 TM |
385 | get_dreq(dreq); |
386 | ||
387 | list_for_each(p, &dreq->rewrite_list) { | |
388 | data = list_entry(p, struct nfs_write_data, pages); | |
389 | ||
390 | get_dreq(dreq); | |
391 | ||
392 | /* | |
393 | * Reset data->res. | |
394 | */ | |
395 | nfs_fattr_init(&data->fattr); | |
396 | data->res.count = data->args.count; | |
397 | memset(&data->verf, 0, sizeof(data->verf)); | |
398 | ||
399 | /* | |
400 | * Reuse data->task; data->args should not have changed | |
401 | * since the original request was sent. | |
402 | */ | |
403 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
404 | &nfs_write_direct_ops, data); | |
405 | NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); | |
406 | ||
407 | data->task.tk_priority = RPC_PRIORITY_NORMAL; | |
408 | data->task.tk_cookie = (unsigned long) inode; | |
409 | ||
410 | /* | |
411 | * We're called via an RPC callback, so BKL is already held. | |
412 | */ | |
413 | rpc_execute(&data->task); | |
414 | ||
415 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
416 | data->task.tk_pid, | |
417 | inode->i_sb->s_id, | |
418 | (long long)NFS_FILEID(inode), | |
419 | data->args.count, | |
420 | (unsigned long long)data->args.offset); | |
421 | } | |
fedb595c | 422 | |
607f31e8 TM |
423 | if (put_dreq(dreq)) |
424 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
425 | } |
426 | ||
427 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
428 | { | |
429 | struct nfs_write_data *data = calldata; | |
430 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
431 | ||
432 | /* Call the NFS version-specific code */ | |
433 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
434 | return; | |
435 | if (unlikely(task->tk_status < 0)) { | |
436 | dreq->error = task->tk_status; | |
437 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
438 | } | |
439 | if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { | |
440 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); | |
441 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
442 | } |
443 | ||
fad61490 TM |
444 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
445 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
446 | } |
447 | ||
fad61490 TM |
448 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
449 | .rpc_call_done = nfs_direct_commit_result, | |
450 | .rpc_release = nfs_commit_release, | |
451 | }; | |
452 | ||
453 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 454 | { |
fad61490 | 455 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 456 | |
fad61490 | 457 | data->inode = dreq->inode; |
a8881f5a | 458 | data->cred = dreq->ctx->cred; |
1da177e4 | 459 | |
fad61490 | 460 | data->args.fh = NFS_FH(data->inode); |
607f31e8 TM |
461 | data->args.offset = 0; |
462 | data->args.count = 0; | |
fad61490 TM |
463 | data->res.count = 0; |
464 | data->res.fattr = &data->fattr; | |
465 | data->res.verf = &data->verf; | |
1da177e4 | 466 | |
fad61490 TM |
467 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
468 | &nfs_commit_direct_ops, data); | |
469 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 470 | |
fad61490 TM |
471 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
472 | data->task.tk_cookie = (unsigned long)data->inode; | |
473 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
474 | dreq->commit_data = NULL; | |
1da177e4 | 475 | |
e99170ff | 476 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 477 | |
fad61490 TM |
478 | lock_kernel(); |
479 | rpc_execute(&data->task); | |
480 | unlock_kernel(); | |
481 | } | |
1da177e4 | 482 | |
fad61490 TM |
483 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
484 | { | |
485 | int flags = dreq->flags; | |
1da177e4 | 486 | |
fad61490 TM |
487 | dreq->flags = 0; |
488 | switch (flags) { | |
489 | case NFS_ODIRECT_DO_COMMIT: | |
490 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 491 | break; |
fad61490 TM |
492 | case NFS_ODIRECT_RESCHED_WRITES: |
493 | nfs_direct_write_reschedule(dreq); | |
494 | break; | |
495 | default: | |
496 | nfs_end_data_update(inode); | |
497 | if (dreq->commit_data != NULL) | |
498 | nfs_commit_free(dreq->commit_data); | |
499 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 500 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
501 | nfs_direct_complete(dreq); |
502 | } | |
503 | } | |
1da177e4 | 504 | |
fad61490 TM |
505 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
506 | { | |
e9f7bee1 | 507 | dreq->commit_data = nfs_commit_alloc(); |
fad61490 TM |
508 | if (dreq->commit_data != NULL) |
509 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
510 | } | |
511 | #else | |
512 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
513 | { | |
514 | dreq->commit_data = NULL; | |
515 | } | |
1da177e4 | 516 | |
fad61490 TM |
517 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
518 | { | |
519 | nfs_end_data_update(inode); | |
520 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 521 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
522 | nfs_direct_complete(dreq); |
523 | } | |
524 | #endif | |
1da177e4 | 525 | |
462d5b32 | 526 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 527 | { |
462d5b32 CL |
528 | struct nfs_write_data *data = calldata; |
529 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
530 | int status = task->tk_status; | |
531 | ||
532 | if (nfs_writeback_done(task, data) != 0) | |
533 | return; | |
462d5b32 | 534 | |
15ce4a0c | 535 | spin_lock(&dreq->lock); |
1da177e4 | 536 | |
eda3cef8 TM |
537 | if (unlikely(status < 0)) { |
538 | dreq->error = status; | |
539 | goto out_unlock; | |
540 | } | |
541 | ||
542 | dreq->count += data->res.count; | |
1da177e4 | 543 | |
fad61490 TM |
544 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
545 | switch (dreq->flags) { | |
546 | case 0: | |
547 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
548 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 549 | break; |
fad61490 TM |
550 | case NFS_ODIRECT_DO_COMMIT: |
551 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
552 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
553 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
554 | } | |
1da177e4 | 555 | } |
1da177e4 | 556 | } |
eda3cef8 | 557 | out_unlock: |
fad61490 | 558 | spin_unlock(&dreq->lock); |
1da177e4 LT |
559 | } |
560 | ||
fad61490 TM |
561 | /* |
562 | * NB: Return the value of the first error return code. Subsequent | |
563 | * errors after the first one are ignored. | |
1da177e4 | 564 | */ |
fad61490 | 565 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 566 | { |
fad61490 TM |
567 | struct nfs_write_data *data = calldata; |
568 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 569 | |
607f31e8 TM |
570 | if (put_dreq(dreq)) |
571 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
572 | } |
573 | ||
574 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
575 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 576 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
577 | }; |
578 | ||
579 | /* | |
607f31e8 TM |
580 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
581 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
582 | * bail and stop sending more writes. Write length accounting is | |
583 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
584 | * no requests have been sent, just return an error. | |
462d5b32 | 585 | */ |
607f31e8 | 586 | 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 | 587 | { |
a8881f5a TM |
588 | struct nfs_open_context *ctx = dreq->ctx; |
589 | struct inode *inode = ctx->dentry->d_inode; | |
462d5b32 | 590 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
591 | unsigned int pgbase; |
592 | int result; | |
593 | ssize_t started = 0; | |
82b145c5 | 594 | |
607f31e8 TM |
595 | get_dreq(dreq); |
596 | ||
1da177e4 | 597 | do { |
82b145c5 | 598 | struct nfs_write_data *data; |
462d5b32 CL |
599 | size_t bytes; |
600 | ||
e9f7bee1 TM |
601 | pgbase = user_addr & ~PAGE_MASK; |
602 | bytes = min(wsize,count); | |
603 | ||
607f31e8 | 604 | result = -ENOMEM; |
e9f7bee1 | 605 | data = nfs_writedata_alloc(pgbase + bytes); |
607f31e8 TM |
606 | if (unlikely(!data)) |
607 | break; | |
608 | ||
607f31e8 TM |
609 | down_read(¤t->mm->mmap_sem); |
610 | result = get_user_pages(current, current->mm, user_addr, | |
611 | data->npages, 0, 0, data->pagevec, NULL); | |
612 | up_read(¤t->mm->mmap_sem); | |
613 | if (unlikely(result < data->npages)) { | |
614 | if (result > 0) | |
615 | nfs_direct_release_pages(data->pagevec, result); | |
616 | nfs_writedata_release(data); | |
617 | break; | |
618 | } | |
619 | ||
620 | get_dreq(dreq); | |
621 | ||
fad61490 | 622 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 623 | |
607f31e8 | 624 | data->req = (struct nfs_page *) dreq; |
462d5b32 CL |
625 | data->inode = inode; |
626 | data->cred = ctx->cred; | |
627 | data->args.fh = NFS_FH(inode); | |
628 | data->args.context = ctx; | |
88467055 | 629 | data->args.offset = pos; |
462d5b32 | 630 | data->args.pgbase = pgbase; |
607f31e8 | 631 | data->args.pages = data->pagevec; |
462d5b32 CL |
632 | data->args.count = bytes; |
633 | data->res.fattr = &data->fattr; | |
634 | data->res.count = bytes; | |
47989d74 | 635 | data->res.verf = &data->verf; |
462d5b32 CL |
636 | |
637 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
638 | &nfs_write_direct_ops, data); | |
fad61490 | 639 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 640 | |
462d5b32 CL |
641 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
642 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
643 | |
644 | lock_kernel(); | |
462d5b32 | 645 | rpc_execute(&data->task); |
1da177e4 LT |
646 | unlock_kernel(); |
647 | ||
606bbba0 | 648 | dfprintk(VFS, "NFS: %5u initiated direct write call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
462d5b32 CL |
649 | data->task.tk_pid, |
650 | inode->i_sb->s_id, | |
651 | (long long)NFS_FILEID(inode), | |
652 | bytes, | |
653 | (unsigned long long)data->args.offset); | |
1da177e4 | 654 | |
607f31e8 TM |
655 | started += bytes; |
656 | user_addr += bytes; | |
88467055 | 657 | pos += bytes; |
e9f7bee1 TM |
658 | |
659 | /* FIXME: Remove this useless math from the final patch */ | |
462d5b32 | 660 | pgbase += bytes; |
462d5b32 | 661 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 662 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 | 663 | |
462d5b32 CL |
664 | count -= bytes; |
665 | } while (count != 0); | |
607f31e8 TM |
666 | |
667 | if (put_dreq(dreq)) | |
668 | nfs_direct_write_complete(dreq, inode); | |
669 | ||
670 | if (started) | |
671 | return 0; | |
672 | return result < 0 ? (ssize_t) result : -EFAULT; | |
462d5b32 | 673 | } |
1da177e4 | 674 | |
607f31e8 | 675 | static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
462d5b32 | 676 | { |
607f31e8 | 677 | ssize_t result = 0; |
462d5b32 | 678 | sigset_t oldset; |
c89f2ee5 | 679 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
680 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
681 | struct nfs_direct_req *dreq; | |
fad61490 TM |
682 | size_t wsize = NFS_SERVER(inode)->wsize; |
683 | int sync = 0; | |
1da177e4 | 684 | |
607f31e8 | 685 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
686 | if (!dreq) |
687 | return -ENOMEM; | |
607f31e8 TM |
688 | nfs_alloc_commit_data(dreq); |
689 | ||
fad61490 TM |
690 | if (dreq->commit_data == NULL || count < wsize) |
691 | sync = FLUSH_STABLE; | |
1da177e4 | 692 | |
c89f2ee5 | 693 | dreq->inode = inode; |
a8881f5a | 694 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
c89f2ee5 CL |
695 | if (!is_sync_kiocb(iocb)) |
696 | dreq->iocb = iocb; | |
1da177e4 | 697 | |
47989d74 CL |
698 | nfs_add_stats(inode, NFSIOS_DIRECTWRITTENBYTES, count); |
699 | ||
462d5b32 | 700 | nfs_begin_data_update(inode); |
1da177e4 | 701 | |
462d5b32 | 702 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
703 | result = nfs_direct_write_schedule(dreq, user_addr, count, pos, sync); |
704 | if (!result) | |
705 | result = nfs_direct_wait(dreq); | |
462d5b32 | 706 | rpc_clnt_sigunmask(clnt, &oldset); |
1da177e4 | 707 | |
1da177e4 LT |
708 | return result; |
709 | } | |
710 | ||
711 | /** | |
712 | * nfs_file_direct_read - file direct read operation for NFS files | |
713 | * @iocb: target I/O control block | |
027445c3 BP |
714 | * @iov: vector of user buffers into which to read data |
715 | * @nr_segs: size of iov vector | |
88467055 | 716 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
717 | * |
718 | * We use this function for direct reads instead of calling | |
719 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
720 | * the request starts before the end of the file. For that check | |
721 | * to work, we must generate a GETATTR before each direct read, and | |
722 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 723 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
724 | * to do all reads the application wants, and the server will take |
725 | * care of managing the end of file boundary. | |
88467055 | 726 | * |
1da177e4 LT |
727 | * This function also eliminates unnecessarily updating the file's |
728 | * atime locally, as the NFS server sets the file's atime, and this | |
729 | * client must read the updated atime from the server back into its | |
730 | * cache. | |
731 | */ | |
027445c3 BP |
732 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
733 | unsigned long nr_segs, loff_t pos) | |
1da177e4 LT |
734 | { |
735 | ssize_t retval = -EINVAL; | |
1da177e4 | 736 | struct file *file = iocb->ki_filp; |
1da177e4 | 737 | struct address_space *mapping = file->f_mapping; |
027445c3 BP |
738 | /* XXX: temporary */ |
739 | const char __user *buf = iov[0].iov_base; | |
740 | size_t count = iov[0].iov_len; | |
1da177e4 | 741 | |
ce1a8e67 | 742 | dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n", |
0bbacc40 CL |
743 | file->f_dentry->d_parent->d_name.name, |
744 | file->f_dentry->d_name.name, | |
ce1a8e67 | 745 | (unsigned long) count, (long long) pos); |
1da177e4 | 746 | |
027445c3 BP |
747 | if (nr_segs != 1) |
748 | return -EINVAL; | |
749 | ||
1da177e4 LT |
750 | if (count < 0) |
751 | goto out; | |
752 | retval = -EFAULT; | |
0cdd80d0 | 753 | if (!access_ok(VERIFY_WRITE, buf, count)) |
1da177e4 LT |
754 | goto out; |
755 | retval = 0; | |
756 | if (!count) | |
757 | goto out; | |
758 | ||
29884df0 TM |
759 | retval = nfs_sync_mapping(mapping); |
760 | if (retval) | |
761 | goto out; | |
1da177e4 | 762 | |
607f31e8 | 763 | retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos); |
1da177e4 | 764 | if (retval > 0) |
0cdd80d0 | 765 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
766 | |
767 | out: | |
768 | return retval; | |
769 | } | |
770 | ||
771 | /** | |
772 | * nfs_file_direct_write - file direct write operation for NFS files | |
773 | * @iocb: target I/O control block | |
027445c3 BP |
774 | * @iov: vector of user buffers from which to write data |
775 | * @nr_segs: size of iov vector | |
88467055 | 776 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
777 | * |
778 | * We use this function for direct writes instead of calling | |
779 | * generic_file_aio_write() in order to avoid taking the inode | |
780 | * semaphore and updating the i_size. The NFS server will set | |
781 | * the new i_size and this client must read the updated size | |
782 | * back into its cache. We let the server do generic write | |
783 | * parameter checking and report problems. | |
784 | * | |
785 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
786 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
787 | * | |
788 | * We eliminate local atime updates, see direct read above. | |
789 | * | |
790 | * We avoid unnecessary page cache invalidations for normal cached | |
791 | * readers of this file. | |
792 | * | |
793 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
794 | * is no atomic O_APPEND write facility in the NFS protocol. | |
795 | */ | |
027445c3 BP |
796 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
797 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 798 | { |
ce1a8e67 | 799 | ssize_t retval; |
1da177e4 | 800 | struct file *file = iocb->ki_filp; |
1da177e4 | 801 | struct address_space *mapping = file->f_mapping; |
027445c3 BP |
802 | /* XXX: temporary */ |
803 | const char __user *buf = iov[0].iov_base; | |
804 | size_t count = iov[0].iov_len; | |
1da177e4 | 805 | |
ce1a8e67 | 806 | dfprintk(VFS, "nfs: direct write(%s/%s, %lu@%Ld)\n", |
0bbacc40 | 807 | file->f_dentry->d_parent->d_name.name, |
ce1a8e67 CL |
808 | file->f_dentry->d_name.name, |
809 | (unsigned long) count, (long long) pos); | |
1da177e4 | 810 | |
027445c3 BP |
811 | if (nr_segs != 1) |
812 | return -EINVAL; | |
813 | ||
ce1a8e67 CL |
814 | retval = generic_write_checks(file, &pos, &count, 0); |
815 | if (retval) | |
1da177e4 | 816 | goto out; |
ce1a8e67 CL |
817 | |
818 | retval = -EINVAL; | |
819 | if ((ssize_t) count < 0) | |
1da177e4 | 820 | goto out; |
1da177e4 LT |
821 | retval = 0; |
822 | if (!count) | |
823 | goto out; | |
ce1a8e67 CL |
824 | |
825 | retval = -EFAULT; | |
47989d74 | 826 | if (!access_ok(VERIFY_READ, buf, count)) |
ce1a8e67 | 827 | goto out; |
1da177e4 | 828 | |
29884df0 TM |
829 | retval = nfs_sync_mapping(mapping); |
830 | if (retval) | |
831 | goto out; | |
1da177e4 | 832 | |
607f31e8 | 833 | retval = nfs_direct_write(iocb, (unsigned long) buf, count, pos); |
9eafa8cc | 834 | |
1da177e4 | 835 | if (retval > 0) |
ce1a8e67 | 836 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
837 | |
838 | out: | |
839 | return retval; | |
840 | } | |
841 | ||
88467055 CL |
842 | /** |
843 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
844 | * | |
845 | */ | |
f7b422b1 | 846 | int __init nfs_init_directcache(void) |
1da177e4 LT |
847 | { |
848 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
849 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
850 | 0, (SLAB_RECLAIM_ACCOUNT| |
851 | SLAB_MEM_SPREAD), | |
1da177e4 LT |
852 | NULL, NULL); |
853 | if (nfs_direct_cachep == NULL) | |
854 | return -ENOMEM; | |
855 | ||
856 | return 0; | |
857 | } | |
858 | ||
88467055 | 859 | /** |
f7b422b1 | 860 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
861 | * |
862 | */ | |
266bee88 | 863 | void nfs_destroy_directcache(void) |
1da177e4 | 864 | { |
1a1d92c1 | 865 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 866 | } |