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 | ||
1da177e4 LT |
171 | static void nfs_direct_req_release(struct kref *kref) |
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 | ||
bc0fb201 CL |
180 | /* |
181 | * Collects and returns the final error value/byte-count. | |
182 | */ | |
183 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
184 | { | |
15ce4a0c | 185 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
186 | |
187 | /* Async requests don't wait here */ | |
188 | if (dreq->iocb) | |
189 | goto out; | |
190 | ||
d72b7a6b | 191 | result = wait_for_completion_interruptible(&dreq->completion); |
bc0fb201 CL |
192 | |
193 | if (!result) | |
15ce4a0c | 194 | result = dreq->error; |
bc0fb201 | 195 | if (!result) |
15ce4a0c | 196 | result = dreq->count; |
bc0fb201 CL |
197 | |
198 | out: | |
199 | kref_put(&dreq->kref, nfs_direct_req_release); | |
200 | return (ssize_t) result; | |
201 | } | |
202 | ||
63ab46ab | 203 | /* |
607f31e8 TM |
204 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
205 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
206 | */ |
207 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
208 | { | |
63ab46ab | 209 | if (dreq->iocb) { |
15ce4a0c | 210 | long res = (long) dreq->error; |
63ab46ab | 211 | if (!res) |
15ce4a0c | 212 | res = (long) dreq->count; |
63ab46ab | 213 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
214 | } |
215 | complete_all(&dreq->completion); | |
63ab46ab CL |
216 | |
217 | kref_put(&dreq->kref, nfs_direct_req_release); | |
218 | } | |
219 | ||
06cf6f2e | 220 | /* |
607f31e8 TM |
221 | * We must hold a reference to all the pages in this direct read request |
222 | * until the RPCs complete. This could be long *after* we are woken up in | |
223 | * nfs_direct_wait (for instance, if someone hits ^C on a slow server). | |
06cf6f2e | 224 | */ |
ec06c096 | 225 | static void nfs_direct_read_result(struct rpc_task *task, void *calldata) |
1da177e4 | 226 | { |
ec06c096 | 227 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
228 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; |
229 | ||
ec06c096 TM |
230 | if (nfs_readpage_result(task, data) != 0) |
231 | return; | |
15ce4a0c CL |
232 | |
233 | spin_lock(&dreq->lock); | |
d4a8f367 | 234 | if (unlikely(task->tk_status < 0)) { |
15ce4a0c | 235 | dreq->error = task->tk_status; |
d4a8f367 TM |
236 | spin_unlock(&dreq->lock); |
237 | } else { | |
238 | dreq->count += data->res.count; | |
239 | spin_unlock(&dreq->lock); | |
240 | nfs_direct_dirty_pages(data->pagevec, | |
241 | data->args.pgbase, | |
242 | data->res.count); | |
243 | } | |
244 | nfs_direct_release_pages(data->pagevec, data->npages); | |
607f31e8 TM |
245 | |
246 | if (put_dreq(dreq)) | |
247 | nfs_direct_complete(dreq); | |
1da177e4 LT |
248 | } |
249 | ||
ec06c096 TM |
250 | static const struct rpc_call_ops nfs_read_direct_ops = { |
251 | .rpc_call_done = nfs_direct_read_result, | |
252 | .rpc_release = nfs_readdata_release, | |
253 | }; | |
254 | ||
d4cc948b | 255 | /* |
607f31e8 TM |
256 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
257 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
258 | * bail and stop sending more reads. Read length accounting is | |
259 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
260 | * no requests have been sent, just return an error. | |
1da177e4 | 261 | */ |
607f31e8 | 262 | static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 263 | { |
a8881f5a TM |
264 | struct nfs_open_context *ctx = dreq->ctx; |
265 | struct inode *inode = ctx->dentry->d_inode; | |
5dd602f2 | 266 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
267 | unsigned int pgbase; |
268 | int result; | |
269 | ssize_t started = 0; | |
270 | ||
271 | get_dreq(dreq); | |
1da177e4 | 272 | |
1da177e4 | 273 | do { |
82b145c5 | 274 | struct nfs_read_data *data; |
5dd602f2 | 275 | size_t bytes; |
1da177e4 | 276 | |
e9f7bee1 TM |
277 | pgbase = user_addr & ~PAGE_MASK; |
278 | bytes = min(rsize,count); | |
279 | ||
607f31e8 | 280 | result = -ENOMEM; |
8d5658c9 | 281 | data = nfs_readdata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
282 | if (unlikely(!data)) |
283 | break; | |
284 | ||
607f31e8 TM |
285 | down_read(¤t->mm->mmap_sem); |
286 | result = get_user_pages(current, current->mm, user_addr, | |
287 | data->npages, 1, 0, data->pagevec, NULL); | |
288 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
289 | if (result < 0) { |
290 | nfs_readdata_release(data); | |
291 | break; | |
292 | } | |
293 | if ((unsigned)result < data->npages) { | |
294 | nfs_direct_release_pages(data->pagevec, result); | |
607f31e8 TM |
295 | nfs_readdata_release(data); |
296 | break; | |
297 | } | |
298 | ||
299 | get_dreq(dreq); | |
82b145c5 | 300 | |
607f31e8 | 301 | data->req = (struct nfs_page *) dreq; |
1da177e4 LT |
302 | data->inode = inode; |
303 | data->cred = ctx->cred; | |
304 | data->args.fh = NFS_FH(inode); | |
305 | data->args.context = ctx; | |
88467055 | 306 | data->args.offset = pos; |
1da177e4 | 307 | data->args.pgbase = pgbase; |
607f31e8 | 308 | data->args.pages = data->pagevec; |
1da177e4 LT |
309 | data->args.count = bytes; |
310 | data->res.fattr = &data->fattr; | |
311 | data->res.eof = 0; | |
312 | data->res.count = bytes; | |
313 | ||
ec06c096 TM |
314 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
315 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
316 | NFS_PROTO(inode)->read_setup(data); |
317 | ||
318 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 319 | |
1da177e4 | 320 | rpc_execute(&data->task); |
1da177e4 | 321 | |
a3f565b1 CL |
322 | dprintk("NFS: %5u initiated direct read call " |
323 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
1da177e4 LT |
324 | data->task.tk_pid, |
325 | inode->i_sb->s_id, | |
326 | (long long)NFS_FILEID(inode), | |
327 | bytes, | |
328 | (unsigned long long)data->args.offset); | |
329 | ||
607f31e8 TM |
330 | started += bytes; |
331 | user_addr += bytes; | |
88467055 | 332 | pos += bytes; |
e9f7bee1 | 333 | /* FIXME: Remove this unnecessary math from final patch */ |
1da177e4 | 334 | pgbase += bytes; |
1da177e4 | 335 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 336 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 LT |
337 | |
338 | count -= bytes; | |
339 | } while (count != 0); | |
607f31e8 TM |
340 | |
341 | if (put_dreq(dreq)) | |
342 | nfs_direct_complete(dreq); | |
343 | ||
344 | if (started) | |
345 | return 0; | |
346 | return result < 0 ? (ssize_t) result : -EFAULT; | |
1da177e4 LT |
347 | } |
348 | ||
607f31e8 | 349 | static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 350 | { |
607f31e8 | 351 | ssize_t result = 0; |
1da177e4 | 352 | sigset_t oldset; |
99514f8f | 353 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
354 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
355 | struct nfs_direct_req *dreq; | |
356 | ||
607f31e8 | 357 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
358 | if (!dreq) |
359 | return -ENOMEM; | |
360 | ||
91d5b470 | 361 | dreq->inode = inode; |
a8881f5a | 362 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
487b8372 CL |
363 | if (!is_sync_kiocb(iocb)) |
364 | dreq->iocb = iocb; | |
1da177e4 | 365 | |
91d5b470 | 366 | nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); |
1da177e4 | 367 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
368 | result = nfs_direct_read_schedule(dreq, user_addr, count, pos); |
369 | if (!result) | |
370 | result = nfs_direct_wait(dreq); | |
1da177e4 LT |
371 | rpc_clnt_sigunmask(clnt, &oldset); |
372 | ||
373 | return result; | |
374 | } | |
375 | ||
fad61490 | 376 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 377 | { |
607f31e8 TM |
378 | while (!list_empty(&dreq->rewrite_list)) { |
379 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 380 | list_del(&data->pages); |
607f31e8 | 381 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
382 | nfs_writedata_release(data); |
383 | } | |
384 | } | |
1da177e4 | 385 | |
fad61490 TM |
386 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
387 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
388 | { | |
607f31e8 TM |
389 | struct inode *inode = dreq->inode; |
390 | struct list_head *p; | |
391 | struct nfs_write_data *data; | |
1da177e4 | 392 | |
fad61490 | 393 | dreq->count = 0; |
607f31e8 TM |
394 | get_dreq(dreq); |
395 | ||
396 | list_for_each(p, &dreq->rewrite_list) { | |
397 | data = list_entry(p, struct nfs_write_data, pages); | |
398 | ||
399 | get_dreq(dreq); | |
400 | ||
401 | /* | |
402 | * Reset data->res. | |
403 | */ | |
404 | nfs_fattr_init(&data->fattr); | |
405 | data->res.count = data->args.count; | |
406 | memset(&data->verf, 0, sizeof(data->verf)); | |
407 | ||
408 | /* | |
409 | * Reuse data->task; data->args should not have changed | |
410 | * since the original request was sent. | |
411 | */ | |
412 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
413 | &nfs_write_direct_ops, data); | |
414 | NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); | |
415 | ||
416 | data->task.tk_priority = RPC_PRIORITY_NORMAL; | |
417 | data->task.tk_cookie = (unsigned long) inode; | |
418 | ||
419 | /* | |
420 | * We're called via an RPC callback, so BKL is already held. | |
421 | */ | |
422 | rpc_execute(&data->task); | |
423 | ||
424 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
425 | data->task.tk_pid, | |
426 | inode->i_sb->s_id, | |
427 | (long long)NFS_FILEID(inode), | |
428 | data->args.count, | |
429 | (unsigned long long)data->args.offset); | |
430 | } | |
fedb595c | 431 | |
607f31e8 TM |
432 | if (put_dreq(dreq)) |
433 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
434 | } |
435 | ||
436 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
437 | { | |
438 | struct nfs_write_data *data = calldata; | |
439 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
440 | ||
441 | /* Call the NFS version-specific code */ | |
442 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
443 | return; | |
444 | if (unlikely(task->tk_status < 0)) { | |
60fa3f76 TM |
445 | dprintk("NFS: %5u commit failed with error %d.\n", |
446 | task->tk_pid, task->tk_status); | |
fad61490 | 447 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
60fa3f76 | 448 | } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { |
fad61490 TM |
449 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); |
450 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
451 | } |
452 | ||
fad61490 TM |
453 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
454 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
455 | } |
456 | ||
fad61490 TM |
457 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
458 | .rpc_call_done = nfs_direct_commit_result, | |
459 | .rpc_release = nfs_commit_release, | |
460 | }; | |
461 | ||
462 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 463 | { |
fad61490 | 464 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 465 | |
fad61490 | 466 | data->inode = dreq->inode; |
a8881f5a | 467 | data->cred = dreq->ctx->cred; |
1da177e4 | 468 | |
fad61490 | 469 | data->args.fh = NFS_FH(data->inode); |
607f31e8 TM |
470 | data->args.offset = 0; |
471 | data->args.count = 0; | |
fad61490 TM |
472 | data->res.count = 0; |
473 | data->res.fattr = &data->fattr; | |
474 | data->res.verf = &data->verf; | |
1da177e4 | 475 | |
fad61490 TM |
476 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
477 | &nfs_commit_direct_ops, data); | |
478 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 479 | |
fad61490 TM |
480 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
481 | data->task.tk_cookie = (unsigned long)data->inode; | |
482 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
483 | dreq->commit_data = NULL; | |
1da177e4 | 484 | |
e99170ff | 485 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 486 | |
fad61490 | 487 | rpc_execute(&data->task); |
fad61490 | 488 | } |
1da177e4 | 489 | |
fad61490 TM |
490 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
491 | { | |
492 | int flags = dreq->flags; | |
1da177e4 | 493 | |
fad61490 TM |
494 | dreq->flags = 0; |
495 | switch (flags) { | |
496 | case NFS_ODIRECT_DO_COMMIT: | |
497 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 498 | break; |
fad61490 TM |
499 | case NFS_ODIRECT_RESCHED_WRITES: |
500 | nfs_direct_write_reschedule(dreq); | |
501 | break; | |
502 | default: | |
503 | nfs_end_data_update(inode); | |
504 | if (dreq->commit_data != NULL) | |
505 | nfs_commit_free(dreq->commit_data); | |
506 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 507 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
508 | nfs_direct_complete(dreq); |
509 | } | |
510 | } | |
1da177e4 | 511 | |
fad61490 TM |
512 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
513 | { | |
e9f7bee1 | 514 | dreq->commit_data = nfs_commit_alloc(); |
fad61490 TM |
515 | if (dreq->commit_data != NULL) |
516 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
517 | } | |
518 | #else | |
519 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
520 | { | |
521 | dreq->commit_data = NULL; | |
522 | } | |
1da177e4 | 523 | |
fad61490 TM |
524 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
525 | { | |
526 | nfs_end_data_update(inode); | |
527 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 528 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
529 | nfs_direct_complete(dreq); |
530 | } | |
531 | #endif | |
1da177e4 | 532 | |
462d5b32 | 533 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 534 | { |
462d5b32 CL |
535 | struct nfs_write_data *data = calldata; |
536 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
537 | int status = task->tk_status; | |
538 | ||
539 | if (nfs_writeback_done(task, data) != 0) | |
540 | return; | |
462d5b32 | 541 | |
15ce4a0c | 542 | spin_lock(&dreq->lock); |
1da177e4 | 543 | |
60fa3f76 TM |
544 | if (unlikely(dreq->error != 0)) |
545 | goto out_unlock; | |
eda3cef8 | 546 | if (unlikely(status < 0)) { |
60fa3f76 TM |
547 | /* An error has occured, so we should not commit */ |
548 | dreq->flags = 0; | |
eda3cef8 | 549 | dreq->error = status; |
eda3cef8 TM |
550 | } |
551 | ||
552 | dreq->count += data->res.count; | |
1da177e4 | 553 | |
fad61490 TM |
554 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
555 | switch (dreq->flags) { | |
556 | case 0: | |
557 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
558 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 559 | break; |
fad61490 TM |
560 | case NFS_ODIRECT_DO_COMMIT: |
561 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
562 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
563 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
564 | } | |
1da177e4 | 565 | } |
1da177e4 | 566 | } |
eda3cef8 | 567 | out_unlock: |
fad61490 | 568 | spin_unlock(&dreq->lock); |
1da177e4 LT |
569 | } |
570 | ||
fad61490 TM |
571 | /* |
572 | * NB: Return the value of the first error return code. Subsequent | |
573 | * errors after the first one are ignored. | |
1da177e4 | 574 | */ |
fad61490 | 575 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 576 | { |
fad61490 TM |
577 | struct nfs_write_data *data = calldata; |
578 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 579 | |
607f31e8 TM |
580 | if (put_dreq(dreq)) |
581 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
582 | } |
583 | ||
584 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
585 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 586 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
587 | }; |
588 | ||
589 | /* | |
607f31e8 TM |
590 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
591 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
592 | * bail and stop sending more writes. Write length accounting is | |
593 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
594 | * no requests have been sent, just return an error. | |
462d5b32 | 595 | */ |
607f31e8 | 596 | 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 | 597 | { |
a8881f5a TM |
598 | struct nfs_open_context *ctx = dreq->ctx; |
599 | struct inode *inode = ctx->dentry->d_inode; | |
462d5b32 | 600 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
601 | unsigned int pgbase; |
602 | int result; | |
603 | ssize_t started = 0; | |
82b145c5 | 604 | |
607f31e8 TM |
605 | get_dreq(dreq); |
606 | ||
1da177e4 | 607 | do { |
82b145c5 | 608 | struct nfs_write_data *data; |
462d5b32 CL |
609 | size_t bytes; |
610 | ||
e9f7bee1 TM |
611 | pgbase = user_addr & ~PAGE_MASK; |
612 | bytes = min(wsize,count); | |
613 | ||
607f31e8 | 614 | result = -ENOMEM; |
8d5658c9 | 615 | data = nfs_writedata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
616 | if (unlikely(!data)) |
617 | break; | |
618 | ||
607f31e8 TM |
619 | down_read(¤t->mm->mmap_sem); |
620 | result = get_user_pages(current, current->mm, user_addr, | |
621 | data->npages, 0, 0, data->pagevec, NULL); | |
622 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
623 | if (result < 0) { |
624 | nfs_writedata_release(data); | |
625 | break; | |
626 | } | |
627 | if ((unsigned)result < data->npages) { | |
628 | nfs_direct_release_pages(data->pagevec, result); | |
607f31e8 TM |
629 | nfs_writedata_release(data); |
630 | break; | |
631 | } | |
632 | ||
633 | get_dreq(dreq); | |
634 | ||
fad61490 | 635 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 636 | |
607f31e8 | 637 | data->req = (struct nfs_page *) dreq; |
462d5b32 CL |
638 | data->inode = inode; |
639 | data->cred = ctx->cred; | |
640 | data->args.fh = NFS_FH(inode); | |
641 | data->args.context = ctx; | |
88467055 | 642 | data->args.offset = pos; |
462d5b32 | 643 | data->args.pgbase = pgbase; |
607f31e8 | 644 | data->args.pages = data->pagevec; |
462d5b32 CL |
645 | data->args.count = bytes; |
646 | data->res.fattr = &data->fattr; | |
647 | data->res.count = bytes; | |
47989d74 | 648 | data->res.verf = &data->verf; |
462d5b32 CL |
649 | |
650 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
651 | &nfs_write_direct_ops, data); | |
fad61490 | 652 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 653 | |
462d5b32 CL |
654 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
655 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 656 | |
462d5b32 | 657 | rpc_execute(&data->task); |
1da177e4 | 658 | |
a3f565b1 CL |
659 | dprintk("NFS: %5u initiated direct write call " |
660 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
462d5b32 CL |
661 | data->task.tk_pid, |
662 | inode->i_sb->s_id, | |
663 | (long long)NFS_FILEID(inode), | |
664 | bytes, | |
665 | (unsigned long long)data->args.offset); | |
1da177e4 | 666 | |
607f31e8 TM |
667 | started += bytes; |
668 | user_addr += bytes; | |
88467055 | 669 | pos += bytes; |
e9f7bee1 TM |
670 | |
671 | /* FIXME: Remove this useless math from the final patch */ | |
462d5b32 | 672 | pgbase += bytes; |
462d5b32 | 673 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 674 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 | 675 | |
462d5b32 CL |
676 | count -= bytes; |
677 | } while (count != 0); | |
607f31e8 TM |
678 | |
679 | if (put_dreq(dreq)) | |
680 | nfs_direct_write_complete(dreq, inode); | |
681 | ||
682 | if (started) | |
683 | return 0; | |
684 | return result < 0 ? (ssize_t) result : -EFAULT; | |
462d5b32 | 685 | } |
1da177e4 | 686 | |
607f31e8 | 687 | static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
462d5b32 | 688 | { |
607f31e8 | 689 | ssize_t result = 0; |
462d5b32 | 690 | sigset_t oldset; |
c89f2ee5 | 691 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
692 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
693 | struct nfs_direct_req *dreq; | |
fad61490 TM |
694 | size_t wsize = NFS_SERVER(inode)->wsize; |
695 | int sync = 0; | |
1da177e4 | 696 | |
607f31e8 | 697 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
698 | if (!dreq) |
699 | return -ENOMEM; | |
607f31e8 TM |
700 | nfs_alloc_commit_data(dreq); |
701 | ||
fad61490 TM |
702 | if (dreq->commit_data == NULL || count < wsize) |
703 | sync = FLUSH_STABLE; | |
1da177e4 | 704 | |
c89f2ee5 | 705 | dreq->inode = inode; |
a8881f5a | 706 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
c89f2ee5 CL |
707 | if (!is_sync_kiocb(iocb)) |
708 | dreq->iocb = iocb; | |
1da177e4 | 709 | |
47989d74 CL |
710 | nfs_add_stats(inode, NFSIOS_DIRECTWRITTENBYTES, count); |
711 | ||
462d5b32 | 712 | nfs_begin_data_update(inode); |
1da177e4 | 713 | |
462d5b32 | 714 | rpc_clnt_sigmask(clnt, &oldset); |
607f31e8 TM |
715 | result = nfs_direct_write_schedule(dreq, user_addr, count, pos, sync); |
716 | if (!result) | |
717 | result = nfs_direct_wait(dreq); | |
462d5b32 | 718 | rpc_clnt_sigunmask(clnt, &oldset); |
1da177e4 | 719 | |
1da177e4 LT |
720 | return result; |
721 | } | |
722 | ||
723 | /** | |
724 | * nfs_file_direct_read - file direct read operation for NFS files | |
725 | * @iocb: target I/O control block | |
027445c3 BP |
726 | * @iov: vector of user buffers into which to read data |
727 | * @nr_segs: size of iov vector | |
88467055 | 728 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
729 | * |
730 | * We use this function for direct reads instead of calling | |
731 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
732 | * the request starts before the end of the file. For that check | |
733 | * to work, we must generate a GETATTR before each direct read, and | |
734 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 735 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
736 | * to do all reads the application wants, and the server will take |
737 | * care of managing the end of file boundary. | |
88467055 | 738 | * |
1da177e4 LT |
739 | * This function also eliminates unnecessarily updating the file's |
740 | * atime locally, as the NFS server sets the file's atime, and this | |
741 | * client must read the updated atime from the server back into its | |
742 | * cache. | |
743 | */ | |
027445c3 BP |
744 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
745 | unsigned long nr_segs, loff_t pos) | |
1da177e4 LT |
746 | { |
747 | ssize_t retval = -EINVAL; | |
1da177e4 | 748 | struct file *file = iocb->ki_filp; |
1da177e4 | 749 | struct address_space *mapping = file->f_mapping; |
027445c3 BP |
750 | /* XXX: temporary */ |
751 | const char __user *buf = iov[0].iov_base; | |
752 | size_t count = iov[0].iov_len; | |
1da177e4 | 753 | |
ce1a8e67 | 754 | dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n", |
01cce933 JJS |
755 | file->f_path.dentry->d_parent->d_name.name, |
756 | file->f_path.dentry->d_name.name, | |
ce1a8e67 | 757 | (unsigned long) count, (long long) pos); |
1da177e4 | 758 | |
027445c3 BP |
759 | if (nr_segs != 1) |
760 | return -EINVAL; | |
761 | ||
1da177e4 LT |
762 | if (count < 0) |
763 | goto out; | |
764 | retval = -EFAULT; | |
0cdd80d0 | 765 | if (!access_ok(VERIFY_WRITE, buf, count)) |
1da177e4 LT |
766 | goto out; |
767 | retval = 0; | |
768 | if (!count) | |
769 | goto out; | |
770 | ||
29884df0 TM |
771 | retval = nfs_sync_mapping(mapping); |
772 | if (retval) | |
773 | goto out; | |
1da177e4 | 774 | |
607f31e8 | 775 | retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos); |
1da177e4 | 776 | if (retval > 0) |
0cdd80d0 | 777 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
778 | |
779 | out: | |
780 | return retval; | |
781 | } | |
782 | ||
783 | /** | |
784 | * nfs_file_direct_write - file direct write operation for NFS files | |
785 | * @iocb: target I/O control block | |
027445c3 BP |
786 | * @iov: vector of user buffers from which to write data |
787 | * @nr_segs: size of iov vector | |
88467055 | 788 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
789 | * |
790 | * We use this function for direct writes instead of calling | |
791 | * generic_file_aio_write() in order to avoid taking the inode | |
792 | * semaphore and updating the i_size. The NFS server will set | |
793 | * the new i_size and this client must read the updated size | |
794 | * back into its cache. We let the server do generic write | |
795 | * parameter checking and report problems. | |
796 | * | |
797 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
798 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
799 | * | |
800 | * We eliminate local atime updates, see direct read above. | |
801 | * | |
802 | * We avoid unnecessary page cache invalidations for normal cached | |
803 | * readers of this file. | |
804 | * | |
805 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
806 | * is no atomic O_APPEND write facility in the NFS protocol. | |
807 | */ | |
027445c3 BP |
808 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
809 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 810 | { |
ce1a8e67 | 811 | ssize_t retval; |
1da177e4 | 812 | struct file *file = iocb->ki_filp; |
1da177e4 | 813 | struct address_space *mapping = file->f_mapping; |
027445c3 BP |
814 | /* XXX: temporary */ |
815 | const char __user *buf = iov[0].iov_base; | |
816 | size_t count = iov[0].iov_len; | |
1da177e4 | 817 | |
a3f565b1 | 818 | dprintk("nfs: direct write(%s/%s, %lu@%Ld)\n", |
01cce933 JJS |
819 | file->f_path.dentry->d_parent->d_name.name, |
820 | file->f_path.dentry->d_name.name, | |
ce1a8e67 | 821 | (unsigned long) count, (long long) pos); |
1da177e4 | 822 | |
027445c3 BP |
823 | if (nr_segs != 1) |
824 | return -EINVAL; | |
825 | ||
ce1a8e67 CL |
826 | retval = generic_write_checks(file, &pos, &count, 0); |
827 | if (retval) | |
1da177e4 | 828 | goto out; |
ce1a8e67 CL |
829 | |
830 | retval = -EINVAL; | |
831 | if ((ssize_t) count < 0) | |
1da177e4 | 832 | goto out; |
1da177e4 LT |
833 | retval = 0; |
834 | if (!count) | |
835 | goto out; | |
ce1a8e67 CL |
836 | |
837 | retval = -EFAULT; | |
47989d74 | 838 | if (!access_ok(VERIFY_READ, buf, count)) |
ce1a8e67 | 839 | goto out; |
1da177e4 | 840 | |
29884df0 TM |
841 | retval = nfs_sync_mapping(mapping); |
842 | if (retval) | |
843 | goto out; | |
1da177e4 | 844 | |
607f31e8 | 845 | retval = nfs_direct_write(iocb, (unsigned long) buf, count, pos); |
9eafa8cc | 846 | |
1da177e4 | 847 | if (retval > 0) |
ce1a8e67 | 848 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
849 | |
850 | out: | |
851 | return retval; | |
852 | } | |
853 | ||
88467055 CL |
854 | /** |
855 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
856 | * | |
857 | */ | |
f7b422b1 | 858 | int __init nfs_init_directcache(void) |
1da177e4 LT |
859 | { |
860 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
861 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
862 | 0, (SLAB_RECLAIM_ACCOUNT| |
863 | SLAB_MEM_SPREAD), | |
1da177e4 LT |
864 | NULL, NULL); |
865 | if (nfs_direct_cachep == NULL) | |
866 | return -ENOMEM; | |
867 | ||
868 | return 0; | |
869 | } | |
870 | ||
88467055 | 871 | /** |
f7b422b1 | 872 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
873 | * |
874 | */ | |
266bee88 | 875 | void nfs_destroy_directcache(void) |
1da177e4 | 876 | { |
1a1d92c1 | 877 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 878 | } |