Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/nfs/direct.c | |
3 | * | |
4 | * Copyright (C) 2003 by Chuck Lever <cel@netapp.com> | |
5 | * | |
6 | * High-performance uncached I/O for the Linux NFS client | |
7 | * | |
8 | * There are important applications whose performance or correctness | |
9 | * depends on uncached access to file data. Database clusters | |
88467055 | 10 | * (multiple copies of the same instance running on separate hosts) |
1da177e4 | 11 | * implement their own cache coherency protocol that subsumes file |
88467055 CL |
12 | * system cache protocols. Applications that process datasets |
13 | * considerably larger than the client's memory do not always benefit | |
14 | * from a local cache. A streaming video server, for instance, has no | |
1da177e4 LT |
15 | * need to cache the contents of a file. |
16 | * | |
17 | * When an application requests uncached I/O, all read and write requests | |
18 | * are made directly to the server; data stored or fetched via these | |
19 | * requests is not cached in the Linux page cache. The client does not | |
20 | * correct unaligned requests from applications. All requested bytes are | |
21 | * held on permanent storage before a direct write system call returns to | |
22 | * an application. | |
23 | * | |
24 | * Solaris implements an uncached I/O facility called directio() that | |
25 | * is used for backups and sequential I/O to very large files. Solaris | |
26 | * also supports uncaching whole NFS partitions with "-o forcedirectio," | |
27 | * an undocumented mount option. | |
28 | * | |
29 | * Designed by Jeff Kimmel, Chuck Lever, and Trond Myklebust, with | |
30 | * help from Andrew Morton. | |
31 | * | |
32 | * 18 Dec 2001 Initial implementation for 2.4 --cel | |
33 | * 08 Jul 2002 Version for 2.4.19, with bug fixes --trondmy | |
34 | * 08 Jun 2003 Port to 2.5 APIs --cel | |
35 | * 31 Mar 2004 Handle direct I/O without VFS support --cel | |
36 | * 15 Sep 2004 Parallel async reads --cel | |
88467055 | 37 | * 04 May 2005 support O_DIRECT with aio --cel |
1da177e4 LT |
38 | * |
39 | */ | |
40 | ||
1da177e4 LT |
41 | #include <linux/errno.h> |
42 | #include <linux/sched.h> | |
43 | #include <linux/kernel.h> | |
1da177e4 LT |
44 | #include <linux/file.h> |
45 | #include <linux/pagemap.h> | |
46 | #include <linux/kref.h> | |
47 | ||
48 | #include <linux/nfs_fs.h> | |
49 | #include <linux/nfs_page.h> | |
50 | #include <linux/sunrpc/clnt.h> | |
51 | ||
52 | #include <asm/system.h> | |
53 | #include <asm/uaccess.h> | |
54 | #include <asm/atomic.h> | |
55 | ||
8d5658c9 | 56 | #include "internal.h" |
91d5b470 CL |
57 | #include "iostat.h" |
58 | ||
1da177e4 | 59 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 | 60 | |
e18b890b | 61 | static struct kmem_cache *nfs_direct_cachep; |
1da177e4 LT |
62 | |
63 | /* | |
64 | * This represents a set of asynchronous requests that we're waiting on | |
65 | */ | |
66 | struct nfs_direct_req { | |
67 | struct kref kref; /* release manager */ | |
15ce4a0c CL |
68 | |
69 | /* I/O parameters */ | |
a8881f5a | 70 | struct nfs_open_context *ctx; /* file open context info */ |
99514f8f | 71 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 72 | struct inode * inode; /* target file of i/o */ |
15ce4a0c CL |
73 | |
74 | /* completion state */ | |
607f31e8 | 75 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 76 | spinlock_t lock; /* protect completion state */ |
15ce4a0c | 77 | ssize_t count, /* bytes actually processed */ |
1da177e4 | 78 | error; /* any reported error */ |
d72b7a6b | 79 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
80 | |
81 | /* commit state */ | |
607f31e8 | 82 | struct list_head rewrite_list; /* saved nfs_write_data structs */ |
fad61490 TM |
83 | struct nfs_write_data * commit_data; /* special write_data for commits */ |
84 | int flags; | |
85 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ | |
86 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
87 | struct nfs_writeverf verf; /* unstable write verifier */ | |
1da177e4 LT |
88 | }; |
89 | ||
fad61490 | 90 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); |
607f31e8 TM |
91 | static const struct rpc_call_ops nfs_write_direct_ops; |
92 | ||
93 | static inline void get_dreq(struct nfs_direct_req *dreq) | |
94 | { | |
95 | atomic_inc(&dreq->io_count); | |
96 | } | |
97 | ||
98 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
99 | { | |
100 | return atomic_dec_and_test(&dreq->io_count); | |
101 | } | |
102 | ||
1da177e4 | 103 | /** |
b8a32e2b CL |
104 | * nfs_direct_IO - NFS address space operation for direct I/O |
105 | * @rw: direction (read or write) | |
106 | * @iocb: target I/O control block | |
107 | * @iov: array of vectors that define I/O buffer | |
108 | * @pos: offset in file to begin the operation | |
109 | * @nr_segs: size of iovec array | |
110 | * | |
111 | * The presence of this routine in the address space ops vector means | |
112 | * the NFS client supports direct I/O. However, we shunt off direct | |
113 | * read and write requests before the VFS gets them, so this method | |
114 | * should never be called. | |
1da177e4 | 115 | */ |
b8a32e2b CL |
116 | ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) |
117 | { | |
b8a32e2b | 118 | dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", |
01cce933 | 119 | iocb->ki_filp->f_path.dentry->d_name.name, |
e99170ff | 120 | (long long) pos, nr_segs); |
b8a32e2b CL |
121 | |
122 | return -EINVAL; | |
123 | } | |
124 | ||
d4a8f367 | 125 | static void nfs_direct_dirty_pages(struct page **pages, unsigned int pgbase, size_t count) |
6b45d858 | 126 | { |
d4a8f367 | 127 | unsigned int npages; |
749e146e | 128 | unsigned int i; |
d4a8f367 TM |
129 | |
130 | if (count == 0) | |
131 | return; | |
132 | pages += (pgbase >> PAGE_SHIFT); | |
133 | npages = (count + (pgbase & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
6b45d858 TM |
134 | for (i = 0; i < npages; i++) { |
135 | struct page *page = pages[i]; | |
607f31e8 | 136 | if (!PageCompound(page)) |
d4a8f367 | 137 | set_page_dirty(page); |
6b45d858 | 138 | } |
9c93ab7d CL |
139 | } |
140 | ||
749e146e | 141 | static void nfs_direct_release_pages(struct page **pages, unsigned int npages) |
9c93ab7d | 142 | { |
749e146e | 143 | unsigned int i; |
607f31e8 TM |
144 | for (i = 0; i < npages; i++) |
145 | page_cache_release(pages[i]); | |
6b45d858 TM |
146 | } |
147 | ||
93619e59 | 148 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 149 | { |
93619e59 CL |
150 | struct nfs_direct_req *dreq; |
151 | ||
e94b1766 | 152 | dreq = kmem_cache_alloc(nfs_direct_cachep, GFP_KERNEL); |
93619e59 CL |
153 | if (!dreq) |
154 | return NULL; | |
155 | ||
156 | kref_init(&dreq->kref); | |
607f31e8 | 157 | kref_get(&dreq->kref); |
d72b7a6b | 158 | init_completion(&dreq->completion); |
fad61490 | 159 | INIT_LIST_HEAD(&dreq->rewrite_list); |
93619e59 | 160 | dreq->iocb = NULL; |
a8881f5a | 161 | dreq->ctx = NULL; |
15ce4a0c | 162 | spin_lock_init(&dreq->lock); |
607f31e8 | 163 | atomic_set(&dreq->io_count, 0); |
15ce4a0c CL |
164 | dreq->count = 0; |
165 | dreq->error = 0; | |
fad61490 | 166 | dreq->flags = 0; |
93619e59 CL |
167 | |
168 | return dreq; | |
1da177e4 LT |
169 | } |
170 | ||
b4946ffb | 171 | static void nfs_direct_req_free(struct kref *kref) |
1da177e4 LT |
172 | { |
173 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a TM |
174 | |
175 | if (dreq->ctx != NULL) | |
176 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
177 | kmem_cache_free(nfs_direct_cachep, dreq); |
178 | } | |
179 | ||
b4946ffb TM |
180 | static void nfs_direct_req_release(struct nfs_direct_req *dreq) |
181 | { | |
182 | kref_put(&dreq->kref, nfs_direct_req_free); | |
183 | } | |
184 | ||
bc0fb201 CL |
185 | /* |
186 | * Collects and returns the final error value/byte-count. | |
187 | */ | |
188 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
189 | { | |
15ce4a0c | 190 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
191 | |
192 | /* Async requests don't wait here */ | |
193 | if (dreq->iocb) | |
194 | goto out; | |
195 | ||
d72b7a6b | 196 | result = wait_for_completion_interruptible(&dreq->completion); |
bc0fb201 CL |
197 | |
198 | if (!result) | |
15ce4a0c | 199 | result = dreq->error; |
bc0fb201 | 200 | if (!result) |
15ce4a0c | 201 | result = dreq->count; |
bc0fb201 CL |
202 | |
203 | out: | |
bc0fb201 CL |
204 | return (ssize_t) result; |
205 | } | |
206 | ||
63ab46ab | 207 | /* |
607f31e8 TM |
208 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
209 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
210 | */ |
211 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
212 | { | |
63ab46ab | 213 | if (dreq->iocb) { |
15ce4a0c | 214 | long res = (long) dreq->error; |
63ab46ab | 215 | if (!res) |
15ce4a0c | 216 | res = (long) dreq->count; |
63ab46ab | 217 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
218 | } |
219 | complete_all(&dreq->completion); | |
63ab46ab | 220 | |
b4946ffb | 221 | nfs_direct_req_release(dreq); |
63ab46ab CL |
222 | } |
223 | ||
06cf6f2e | 224 | /* |
607f31e8 TM |
225 | * We must hold a reference to all the pages in this direct read request |
226 | * until the RPCs complete. This could be long *after* we are woken up in | |
227 | * nfs_direct_wait (for instance, if someone hits ^C on a slow server). | |
06cf6f2e | 228 | */ |
ec06c096 | 229 | static void nfs_direct_read_result(struct rpc_task *task, void *calldata) |
1da177e4 | 230 | { |
ec06c096 | 231 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
232 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; |
233 | ||
ec06c096 TM |
234 | if (nfs_readpage_result(task, data) != 0) |
235 | return; | |
15ce4a0c CL |
236 | |
237 | spin_lock(&dreq->lock); | |
d4a8f367 | 238 | if (unlikely(task->tk_status < 0)) { |
15ce4a0c | 239 | dreq->error = task->tk_status; |
d4a8f367 TM |
240 | spin_unlock(&dreq->lock); |
241 | } else { | |
242 | dreq->count += data->res.count; | |
243 | spin_unlock(&dreq->lock); | |
244 | nfs_direct_dirty_pages(data->pagevec, | |
245 | data->args.pgbase, | |
246 | data->res.count); | |
247 | } | |
248 | nfs_direct_release_pages(data->pagevec, data->npages); | |
607f31e8 TM |
249 | |
250 | if (put_dreq(dreq)) | |
251 | nfs_direct_complete(dreq); | |
1da177e4 LT |
252 | } |
253 | ||
ec06c096 TM |
254 | static const struct rpc_call_ops nfs_read_direct_ops = { |
255 | .rpc_call_done = nfs_direct_read_result, | |
256 | .rpc_release = nfs_readdata_release, | |
257 | }; | |
258 | ||
d4cc948b | 259 | /* |
607f31e8 TM |
260 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
261 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
262 | * bail and stop sending more reads. Read length accounting is | |
263 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
264 | * no requests have been sent, just return an error. | |
1da177e4 | 265 | */ |
607f31e8 | 266 | static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 267 | { |
a8881f5a | 268 | struct nfs_open_context *ctx = dreq->ctx; |
88be9f99 | 269 | struct inode *inode = ctx->path.dentry->d_inode; |
5dd602f2 | 270 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
271 | unsigned int pgbase; |
272 | int result; | |
273 | ssize_t started = 0; | |
274 | ||
1da177e4 | 275 | do { |
82b145c5 | 276 | struct nfs_read_data *data; |
5dd602f2 | 277 | size_t bytes; |
1da177e4 | 278 | |
e9f7bee1 TM |
279 | pgbase = user_addr & ~PAGE_MASK; |
280 | bytes = min(rsize,count); | |
281 | ||
607f31e8 | 282 | result = -ENOMEM; |
8d5658c9 | 283 | data = nfs_readdata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
284 | if (unlikely(!data)) |
285 | break; | |
286 | ||
607f31e8 TM |
287 | down_read(¤t->mm->mmap_sem); |
288 | result = get_user_pages(current, current->mm, user_addr, | |
289 | data->npages, 1, 0, data->pagevec, NULL); | |
290 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
291 | if (result < 0) { |
292 | nfs_readdata_release(data); | |
293 | break; | |
294 | } | |
295 | if ((unsigned)result < data->npages) { | |
d9df8d6b TM |
296 | bytes = result * PAGE_SIZE; |
297 | if (bytes <= pgbase) { | |
298 | nfs_direct_release_pages(data->pagevec, result); | |
299 | nfs_readdata_release(data); | |
300 | break; | |
301 | } | |
302 | bytes -= pgbase; | |
303 | data->npages = result; | |
607f31e8 TM |
304 | } |
305 | ||
306 | get_dreq(dreq); | |
82b145c5 | 307 | |
607f31e8 | 308 | data->req = (struct nfs_page *) dreq; |
1da177e4 LT |
309 | data->inode = inode; |
310 | data->cred = ctx->cred; | |
311 | data->args.fh = NFS_FH(inode); | |
312 | data->args.context = ctx; | |
88467055 | 313 | data->args.offset = pos; |
1da177e4 | 314 | data->args.pgbase = pgbase; |
607f31e8 | 315 | data->args.pages = data->pagevec; |
1da177e4 LT |
316 | data->args.count = bytes; |
317 | data->res.fattr = &data->fattr; | |
318 | data->res.eof = 0; | |
319 | data->res.count = bytes; | |
320 | ||
ec06c096 TM |
321 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
322 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
323 | NFS_PROTO(inode)->read_setup(data); |
324 | ||
325 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 326 | |
1da177e4 | 327 | rpc_execute(&data->task); |
1da177e4 | 328 | |
a3f565b1 CL |
329 | dprintk("NFS: %5u initiated direct read call " |
330 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
1da177e4 LT |
331 | data->task.tk_pid, |
332 | inode->i_sb->s_id, | |
333 | (long long)NFS_FILEID(inode), | |
334 | bytes, | |
335 | (unsigned long long)data->args.offset); | |
336 | ||
607f31e8 TM |
337 | started += bytes; |
338 | user_addr += bytes; | |
88467055 | 339 | pos += bytes; |
e9f7bee1 | 340 | /* FIXME: Remove this unnecessary math from final patch */ |
1da177e4 | 341 | pgbase += bytes; |
1da177e4 | 342 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 343 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 LT |
344 | |
345 | count -= bytes; | |
346 | } while (count != 0); | |
607f31e8 | 347 | |
607f31e8 | 348 | if (started) |
c216fd70 | 349 | return started; |
607f31e8 | 350 | return result < 0 ? (ssize_t) result : -EFAULT; |
1da177e4 LT |
351 | } |
352 | ||
19f73787 CL |
353 | static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, |
354 | const struct iovec *iov, | |
355 | unsigned long nr_segs, | |
356 | loff_t pos) | |
357 | { | |
358 | ssize_t result = -EINVAL; | |
359 | size_t requested_bytes = 0; | |
360 | unsigned long seg; | |
361 | ||
362 | get_dreq(dreq); | |
363 | ||
364 | for (seg = 0; seg < nr_segs; seg++) { | |
365 | const struct iovec *vec = &iov[seg]; | |
366 | result = nfs_direct_read_schedule(dreq, | |
367 | (unsigned long)vec->iov_base, | |
368 | vec->iov_len, pos); | |
369 | if (result < 0) | |
370 | break; | |
371 | requested_bytes += result; | |
372 | if ((size_t)result < vec->iov_len) | |
373 | break; | |
374 | pos += vec->iov_len; | |
375 | } | |
376 | ||
377 | if (put_dreq(dreq)) | |
378 | nfs_direct_complete(dreq); | |
379 | ||
380 | if (requested_bytes != 0) | |
381 | return 0; | |
382 | ||
383 | if (result < 0) | |
384 | return result; | |
385 | return -EIO; | |
386 | } | |
387 | ||
c216fd70 CL |
388 | static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, |
389 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 390 | { |
607f31e8 | 391 | ssize_t result = 0; |
1da177e4 | 392 | sigset_t oldset; |
99514f8f | 393 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
394 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
395 | struct nfs_direct_req *dreq; | |
396 | ||
607f31e8 | 397 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
398 | if (!dreq) |
399 | return -ENOMEM; | |
400 | ||
91d5b470 | 401 | dreq->inode = inode; |
cd3758e3 | 402 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
487b8372 CL |
403 | if (!is_sync_kiocb(iocb)) |
404 | dreq->iocb = iocb; | |
1da177e4 LT |
405 | |
406 | rpc_clnt_sigmask(clnt, &oldset); | |
c216fd70 | 407 | result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos); |
607f31e8 TM |
408 | if (!result) |
409 | result = nfs_direct_wait(dreq); | |
1da177e4 | 410 | rpc_clnt_sigunmask(clnt, &oldset); |
b4946ffb | 411 | nfs_direct_req_release(dreq); |
1da177e4 LT |
412 | |
413 | return result; | |
414 | } | |
415 | ||
fad61490 | 416 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 417 | { |
607f31e8 TM |
418 | while (!list_empty(&dreq->rewrite_list)) { |
419 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 420 | list_del(&data->pages); |
607f31e8 | 421 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
422 | nfs_writedata_release(data); |
423 | } | |
424 | } | |
1da177e4 | 425 | |
fad61490 TM |
426 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
427 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
428 | { | |
607f31e8 TM |
429 | struct inode *inode = dreq->inode; |
430 | struct list_head *p; | |
431 | struct nfs_write_data *data; | |
1da177e4 | 432 | |
fad61490 | 433 | dreq->count = 0; |
607f31e8 TM |
434 | get_dreq(dreq); |
435 | ||
436 | list_for_each(p, &dreq->rewrite_list) { | |
437 | data = list_entry(p, struct nfs_write_data, pages); | |
438 | ||
439 | get_dreq(dreq); | |
440 | ||
441 | /* | |
442 | * Reset data->res. | |
443 | */ | |
444 | nfs_fattr_init(&data->fattr); | |
445 | data->res.count = data->args.count; | |
446 | memset(&data->verf, 0, sizeof(data->verf)); | |
447 | ||
448 | /* | |
449 | * Reuse data->task; data->args should not have changed | |
450 | * since the original request was sent. | |
451 | */ | |
452 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
453 | &nfs_write_direct_ops, data); | |
454 | NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); | |
455 | ||
456 | data->task.tk_priority = RPC_PRIORITY_NORMAL; | |
457 | data->task.tk_cookie = (unsigned long) inode; | |
458 | ||
459 | /* | |
460 | * We're called via an RPC callback, so BKL is already held. | |
461 | */ | |
462 | rpc_execute(&data->task); | |
463 | ||
464 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
465 | data->task.tk_pid, | |
466 | inode->i_sb->s_id, | |
467 | (long long)NFS_FILEID(inode), | |
468 | data->args.count, | |
469 | (unsigned long long)data->args.offset); | |
470 | } | |
fedb595c | 471 | |
607f31e8 TM |
472 | if (put_dreq(dreq)) |
473 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
474 | } |
475 | ||
476 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
477 | { | |
478 | struct nfs_write_data *data = calldata; | |
479 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
480 | ||
481 | /* Call the NFS version-specific code */ | |
482 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
483 | return; | |
484 | if (unlikely(task->tk_status < 0)) { | |
60fa3f76 TM |
485 | dprintk("NFS: %5u commit failed with error %d.\n", |
486 | task->tk_pid, task->tk_status); | |
fad61490 | 487 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
60fa3f76 | 488 | } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { |
fad61490 TM |
489 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); |
490 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
491 | } |
492 | ||
fad61490 TM |
493 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
494 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
495 | } |
496 | ||
fad61490 TM |
497 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
498 | .rpc_call_done = nfs_direct_commit_result, | |
499 | .rpc_release = nfs_commit_release, | |
500 | }; | |
501 | ||
502 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 503 | { |
fad61490 | 504 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 505 | |
fad61490 | 506 | data->inode = dreq->inode; |
a8881f5a | 507 | data->cred = dreq->ctx->cred; |
1da177e4 | 508 | |
fad61490 | 509 | data->args.fh = NFS_FH(data->inode); |
607f31e8 TM |
510 | data->args.offset = 0; |
511 | data->args.count = 0; | |
fad61490 TM |
512 | data->res.count = 0; |
513 | data->res.fattr = &data->fattr; | |
514 | data->res.verf = &data->verf; | |
1da177e4 | 515 | |
fad61490 TM |
516 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
517 | &nfs_commit_direct_ops, data); | |
518 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 519 | |
fad61490 TM |
520 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
521 | data->task.tk_cookie = (unsigned long)data->inode; | |
522 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
523 | dreq->commit_data = NULL; | |
1da177e4 | 524 | |
e99170ff | 525 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 526 | |
fad61490 | 527 | rpc_execute(&data->task); |
fad61490 | 528 | } |
1da177e4 | 529 | |
fad61490 TM |
530 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
531 | { | |
532 | int flags = dreq->flags; | |
1da177e4 | 533 | |
fad61490 TM |
534 | dreq->flags = 0; |
535 | switch (flags) { | |
536 | case NFS_ODIRECT_DO_COMMIT: | |
537 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 538 | break; |
fad61490 TM |
539 | case NFS_ODIRECT_RESCHED_WRITES: |
540 | nfs_direct_write_reschedule(dreq); | |
541 | break; | |
542 | default: | |
fad61490 TM |
543 | if (dreq->commit_data != NULL) |
544 | nfs_commit_free(dreq->commit_data); | |
545 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 546 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
547 | nfs_direct_complete(dreq); |
548 | } | |
549 | } | |
1da177e4 | 550 | |
fad61490 TM |
551 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
552 | { | |
e9f7bee1 | 553 | dreq->commit_data = nfs_commit_alloc(); |
fad61490 TM |
554 | if (dreq->commit_data != NULL) |
555 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
556 | } | |
557 | #else | |
558 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
559 | { | |
560 | dreq->commit_data = NULL; | |
561 | } | |
1da177e4 | 562 | |
fad61490 TM |
563 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
564 | { | |
fad61490 | 565 | nfs_direct_free_writedata(dreq); |
cd9ae2b6 | 566 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
567 | nfs_direct_complete(dreq); |
568 | } | |
569 | #endif | |
1da177e4 | 570 | |
462d5b32 | 571 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 572 | { |
462d5b32 CL |
573 | struct nfs_write_data *data = calldata; |
574 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
575 | int status = task->tk_status; | |
576 | ||
577 | if (nfs_writeback_done(task, data) != 0) | |
578 | return; | |
462d5b32 | 579 | |
15ce4a0c | 580 | spin_lock(&dreq->lock); |
1da177e4 | 581 | |
eda3cef8 | 582 | if (unlikely(status < 0)) { |
432409ee | 583 | /* An error has occurred, so we should not commit */ |
60fa3f76 | 584 | dreq->flags = 0; |
eda3cef8 | 585 | dreq->error = status; |
eda3cef8 | 586 | } |
432409ee NB |
587 | if (unlikely(dreq->error != 0)) |
588 | goto out_unlock; | |
eda3cef8 TM |
589 | |
590 | dreq->count += data->res.count; | |
1da177e4 | 591 | |
fad61490 TM |
592 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
593 | switch (dreq->flags) { | |
594 | case 0: | |
595 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
596 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 597 | break; |
fad61490 TM |
598 | case NFS_ODIRECT_DO_COMMIT: |
599 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
600 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
601 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
602 | } | |
1da177e4 | 603 | } |
1da177e4 | 604 | } |
eda3cef8 | 605 | out_unlock: |
fad61490 | 606 | spin_unlock(&dreq->lock); |
1da177e4 LT |
607 | } |
608 | ||
fad61490 TM |
609 | /* |
610 | * NB: Return the value of the first error return code. Subsequent | |
611 | * errors after the first one are ignored. | |
1da177e4 | 612 | */ |
fad61490 | 613 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 614 | { |
fad61490 TM |
615 | struct nfs_write_data *data = calldata; |
616 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 617 | |
607f31e8 TM |
618 | if (put_dreq(dreq)) |
619 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
620 | } |
621 | ||
622 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
623 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 624 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
625 | }; |
626 | ||
627 | /* | |
607f31e8 TM |
628 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
629 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
630 | * bail and stop sending more writes. Write length accounting is | |
631 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
632 | * no requests have been sent, just return an error. | |
462d5b32 | 633 | */ |
607f31e8 | 634 | 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 | 635 | { |
a8881f5a | 636 | struct nfs_open_context *ctx = dreq->ctx; |
88be9f99 | 637 | struct inode *inode = ctx->path.dentry->d_inode; |
462d5b32 | 638 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
639 | unsigned int pgbase; |
640 | int result; | |
641 | ssize_t started = 0; | |
82b145c5 | 642 | |
1da177e4 | 643 | do { |
82b145c5 | 644 | struct nfs_write_data *data; |
462d5b32 CL |
645 | size_t bytes; |
646 | ||
e9f7bee1 TM |
647 | pgbase = user_addr & ~PAGE_MASK; |
648 | bytes = min(wsize,count); | |
649 | ||
607f31e8 | 650 | result = -ENOMEM; |
8d5658c9 | 651 | data = nfs_writedata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
652 | if (unlikely(!data)) |
653 | break; | |
654 | ||
607f31e8 TM |
655 | down_read(¤t->mm->mmap_sem); |
656 | result = get_user_pages(current, current->mm, user_addr, | |
657 | data->npages, 0, 0, data->pagevec, NULL); | |
658 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
659 | if (result < 0) { |
660 | nfs_writedata_release(data); | |
661 | break; | |
662 | } | |
663 | if ((unsigned)result < data->npages) { | |
d9df8d6b TM |
664 | bytes = result * PAGE_SIZE; |
665 | if (bytes <= pgbase) { | |
666 | nfs_direct_release_pages(data->pagevec, result); | |
667 | nfs_writedata_release(data); | |
668 | break; | |
669 | } | |
670 | bytes -= pgbase; | |
671 | data->npages = result; | |
607f31e8 TM |
672 | } |
673 | ||
674 | get_dreq(dreq); | |
675 | ||
fad61490 | 676 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 677 | |
607f31e8 | 678 | data->req = (struct nfs_page *) dreq; |
462d5b32 CL |
679 | data->inode = inode; |
680 | data->cred = ctx->cred; | |
681 | data->args.fh = NFS_FH(inode); | |
682 | data->args.context = ctx; | |
88467055 | 683 | data->args.offset = pos; |
462d5b32 | 684 | data->args.pgbase = pgbase; |
607f31e8 | 685 | data->args.pages = data->pagevec; |
462d5b32 CL |
686 | data->args.count = bytes; |
687 | data->res.fattr = &data->fattr; | |
688 | data->res.count = bytes; | |
47989d74 | 689 | data->res.verf = &data->verf; |
462d5b32 CL |
690 | |
691 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
692 | &nfs_write_direct_ops, data); | |
fad61490 | 693 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 694 | |
462d5b32 CL |
695 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
696 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 697 | |
462d5b32 | 698 | rpc_execute(&data->task); |
1da177e4 | 699 | |
a3f565b1 CL |
700 | dprintk("NFS: %5u initiated direct write call " |
701 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
462d5b32 CL |
702 | data->task.tk_pid, |
703 | inode->i_sb->s_id, | |
704 | (long long)NFS_FILEID(inode), | |
705 | bytes, | |
706 | (unsigned long long)data->args.offset); | |
1da177e4 | 707 | |
607f31e8 TM |
708 | started += bytes; |
709 | user_addr += bytes; | |
88467055 | 710 | pos += bytes; |
e9f7bee1 TM |
711 | |
712 | /* FIXME: Remove this useless math from the final patch */ | |
462d5b32 | 713 | pgbase += bytes; |
462d5b32 | 714 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 715 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 | 716 | |
462d5b32 CL |
717 | count -= bytes; |
718 | } while (count != 0); | |
607f31e8 | 719 | |
607f31e8 | 720 | if (started) |
c216fd70 | 721 | return started; |
607f31e8 | 722 | return result < 0 ? (ssize_t) result : -EFAULT; |
462d5b32 | 723 | } |
1da177e4 | 724 | |
19f73787 CL |
725 | static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, |
726 | const struct iovec *iov, | |
727 | unsigned long nr_segs, | |
728 | loff_t pos, int sync) | |
729 | { | |
730 | ssize_t result = 0; | |
731 | size_t requested_bytes = 0; | |
732 | unsigned long seg; | |
733 | ||
734 | get_dreq(dreq); | |
735 | ||
736 | for (seg = 0; seg < nr_segs; seg++) { | |
737 | const struct iovec *vec = &iov[seg]; | |
738 | result = nfs_direct_write_schedule(dreq, | |
739 | (unsigned long)vec->iov_base, | |
740 | vec->iov_len, | |
741 | pos, sync); | |
742 | if (result < 0) | |
743 | break; | |
744 | requested_bytes += result; | |
745 | if ((size_t)result < vec->iov_len) | |
746 | break; | |
747 | pos += vec->iov_len; | |
748 | } | |
749 | ||
750 | if (put_dreq(dreq)) | |
751 | nfs_direct_write_complete(dreq, dreq->inode); | |
752 | ||
753 | if (requested_bytes != 0) | |
754 | return 0; | |
755 | ||
756 | if (result < 0) | |
757 | return result; | |
758 | return -EIO; | |
759 | } | |
760 | ||
c216fd70 CL |
761 | static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, |
762 | unsigned long nr_segs, loff_t pos, | |
763 | size_t count) | |
462d5b32 | 764 | { |
607f31e8 | 765 | ssize_t result = 0; |
462d5b32 | 766 | sigset_t oldset; |
c89f2ee5 | 767 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
768 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
769 | struct nfs_direct_req *dreq; | |
fad61490 TM |
770 | size_t wsize = NFS_SERVER(inode)->wsize; |
771 | int sync = 0; | |
1da177e4 | 772 | |
607f31e8 | 773 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
774 | if (!dreq) |
775 | return -ENOMEM; | |
607f31e8 TM |
776 | nfs_alloc_commit_data(dreq); |
777 | ||
fad61490 TM |
778 | if (dreq->commit_data == NULL || count < wsize) |
779 | sync = FLUSH_STABLE; | |
1da177e4 | 780 | |
c89f2ee5 | 781 | dreq->inode = inode; |
cd3758e3 | 782 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
c89f2ee5 CL |
783 | if (!is_sync_kiocb(iocb)) |
784 | dreq->iocb = iocb; | |
1da177e4 | 785 | |
462d5b32 | 786 | rpc_clnt_sigmask(clnt, &oldset); |
c216fd70 | 787 | result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, sync); |
607f31e8 TM |
788 | if (!result) |
789 | result = nfs_direct_wait(dreq); | |
462d5b32 | 790 | rpc_clnt_sigunmask(clnt, &oldset); |
b4946ffb | 791 | nfs_direct_req_release(dreq); |
1da177e4 | 792 | |
1da177e4 LT |
793 | return result; |
794 | } | |
795 | ||
796 | /** | |
797 | * nfs_file_direct_read - file direct read operation for NFS files | |
798 | * @iocb: target I/O control block | |
027445c3 BP |
799 | * @iov: vector of user buffers into which to read data |
800 | * @nr_segs: size of iov vector | |
88467055 | 801 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
802 | * |
803 | * We use this function for direct reads instead of calling | |
804 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
805 | * the request starts before the end of the file. For that check | |
806 | * to work, we must generate a GETATTR before each direct read, and | |
807 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 808 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
809 | * to do all reads the application wants, and the server will take |
810 | * care of managing the end of file boundary. | |
88467055 | 811 | * |
1da177e4 LT |
812 | * This function also eliminates unnecessarily updating the file's |
813 | * atime locally, as the NFS server sets the file's atime, and this | |
814 | * client must read the updated atime from the server back into its | |
815 | * cache. | |
816 | */ | |
027445c3 BP |
817 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
818 | unsigned long nr_segs, loff_t pos) | |
1da177e4 LT |
819 | { |
820 | ssize_t retval = -EINVAL; | |
1da177e4 | 821 | struct file *file = iocb->ki_filp; |
1da177e4 | 822 | struct address_space *mapping = file->f_mapping; |
c216fd70 CL |
823 | size_t count; |
824 | ||
825 | count = iov_length(iov, nr_segs); | |
826 | nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); | |
1da177e4 | 827 | |
c216fd70 | 828 | dprintk("nfs: direct read(%s/%s, %zd@%Ld)\n", |
01cce933 JJS |
829 | file->f_path.dentry->d_parent->d_name.name, |
830 | file->f_path.dentry->d_name.name, | |
c216fd70 | 831 | count, (long long) pos); |
1da177e4 | 832 | |
1da177e4 LT |
833 | retval = 0; |
834 | if (!count) | |
835 | goto out; | |
836 | ||
29884df0 TM |
837 | retval = nfs_sync_mapping(mapping); |
838 | if (retval) | |
839 | goto out; | |
1da177e4 | 840 | |
c216fd70 | 841 | retval = nfs_direct_read(iocb, iov, nr_segs, pos); |
1da177e4 | 842 | if (retval > 0) |
0cdd80d0 | 843 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
844 | |
845 | out: | |
846 | return retval; | |
847 | } | |
848 | ||
849 | /** | |
850 | * nfs_file_direct_write - file direct write operation for NFS files | |
851 | * @iocb: target I/O control block | |
027445c3 BP |
852 | * @iov: vector of user buffers from which to write data |
853 | * @nr_segs: size of iov vector | |
88467055 | 854 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
855 | * |
856 | * We use this function for direct writes instead of calling | |
857 | * generic_file_aio_write() in order to avoid taking the inode | |
858 | * semaphore and updating the i_size. The NFS server will set | |
859 | * the new i_size and this client must read the updated size | |
860 | * back into its cache. We let the server do generic write | |
861 | * parameter checking and report problems. | |
862 | * | |
863 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
864 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
865 | * | |
866 | * We eliminate local atime updates, see direct read above. | |
867 | * | |
868 | * We avoid unnecessary page cache invalidations for normal cached | |
869 | * readers of this file. | |
870 | * | |
871 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
872 | * is no atomic O_APPEND write facility in the NFS protocol. | |
873 | */ | |
027445c3 BP |
874 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
875 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 876 | { |
070ea602 | 877 | ssize_t retval = -EINVAL; |
1da177e4 | 878 | struct file *file = iocb->ki_filp; |
1da177e4 | 879 | struct address_space *mapping = file->f_mapping; |
c216fd70 | 880 | size_t count; |
1da177e4 | 881 | |
c216fd70 CL |
882 | count = iov_length(iov, nr_segs); |
883 | nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); | |
884 | ||
885 | dfprintk(VFS, "nfs: direct write(%s/%s, %zd@%Ld)\n", | |
01cce933 JJS |
886 | file->f_path.dentry->d_parent->d_name.name, |
887 | file->f_path.dentry->d_name.name, | |
c216fd70 | 888 | count, (long long) pos); |
027445c3 | 889 | |
ce1a8e67 CL |
890 | retval = generic_write_checks(file, &pos, &count, 0); |
891 | if (retval) | |
1da177e4 | 892 | goto out; |
b9148c6b CL |
893 | if (!count) |
894 | goto out; /* return 0 */ | |
ce1a8e67 CL |
895 | |
896 | retval = -EINVAL; | |
897 | if ((ssize_t) count < 0) | |
1da177e4 | 898 | goto out; |
1da177e4 LT |
899 | retval = 0; |
900 | if (!count) | |
901 | goto out; | |
ce1a8e67 | 902 | |
29884df0 TM |
903 | retval = nfs_sync_mapping(mapping); |
904 | if (retval) | |
905 | goto out; | |
1da177e4 | 906 | |
c216fd70 | 907 | retval = nfs_direct_write(iocb, iov, nr_segs, pos, count); |
9eafa8cc | 908 | |
1da177e4 | 909 | if (retval > 0) |
ce1a8e67 | 910 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
911 | |
912 | out: | |
913 | return retval; | |
914 | } | |
915 | ||
88467055 CL |
916 | /** |
917 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
918 | * | |
919 | */ | |
f7b422b1 | 920 | int __init nfs_init_directcache(void) |
1da177e4 LT |
921 | { |
922 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
923 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
924 | 0, (SLAB_RECLAIM_ACCOUNT| |
925 | SLAB_MEM_SPREAD), | |
20c2df83 | 926 | NULL); |
1da177e4 LT |
927 | if (nfs_direct_cachep == NULL) |
928 | return -ENOMEM; | |
929 | ||
930 | return 0; | |
931 | } | |
932 | ||
88467055 | 933 | /** |
f7b422b1 | 934 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
935 | * |
936 | */ | |
266bee88 | 937 | void nfs_destroy_directcache(void) |
1da177e4 | 938 | { |
1a1d92c1 | 939 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 940 | } |