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 | */ |
02fe4946 CL |
266 | static ssize_t nfs_direct_read_schedule_segment(struct nfs_direct_req *dreq, |
267 | const struct iovec *iov, | |
268 | loff_t pos) | |
1da177e4 | 269 | { |
a8881f5a | 270 | struct nfs_open_context *ctx = dreq->ctx; |
88be9f99 | 271 | struct inode *inode = ctx->path.dentry->d_inode; |
02fe4946 CL |
272 | unsigned long user_addr = (unsigned long)iov->iov_base; |
273 | size_t count = iov->iov_len; | |
5dd602f2 | 274 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
275 | unsigned int pgbase; |
276 | int result; | |
277 | ssize_t started = 0; | |
278 | ||
1da177e4 | 279 | do { |
82b145c5 | 280 | struct nfs_read_data *data; |
5dd602f2 | 281 | size_t bytes; |
1da177e4 | 282 | |
e9f7bee1 TM |
283 | pgbase = user_addr & ~PAGE_MASK; |
284 | bytes = min(rsize,count); | |
285 | ||
607f31e8 | 286 | result = -ENOMEM; |
8d5658c9 | 287 | data = nfs_readdata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
288 | if (unlikely(!data)) |
289 | break; | |
290 | ||
607f31e8 TM |
291 | down_read(¤t->mm->mmap_sem); |
292 | result = get_user_pages(current, current->mm, user_addr, | |
293 | data->npages, 1, 0, data->pagevec, NULL); | |
294 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
295 | if (result < 0) { |
296 | nfs_readdata_release(data); | |
297 | break; | |
298 | } | |
299 | if ((unsigned)result < data->npages) { | |
d9df8d6b TM |
300 | bytes = result * PAGE_SIZE; |
301 | if (bytes <= pgbase) { | |
302 | nfs_direct_release_pages(data->pagevec, result); | |
303 | nfs_readdata_release(data); | |
304 | break; | |
305 | } | |
306 | bytes -= pgbase; | |
307 | data->npages = result; | |
607f31e8 TM |
308 | } |
309 | ||
310 | get_dreq(dreq); | |
82b145c5 | 311 | |
607f31e8 | 312 | data->req = (struct nfs_page *) dreq; |
1da177e4 LT |
313 | data->inode = inode; |
314 | data->cred = ctx->cred; | |
315 | data->args.fh = NFS_FH(inode); | |
316 | data->args.context = ctx; | |
88467055 | 317 | data->args.offset = pos; |
1da177e4 | 318 | data->args.pgbase = pgbase; |
607f31e8 | 319 | data->args.pages = data->pagevec; |
1da177e4 LT |
320 | data->args.count = bytes; |
321 | data->res.fattr = &data->fattr; | |
322 | data->res.eof = 0; | |
323 | data->res.count = bytes; | |
324 | ||
ec06c096 TM |
325 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
326 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
327 | NFS_PROTO(inode)->read_setup(data); |
328 | ||
329 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 330 | |
1da177e4 | 331 | rpc_execute(&data->task); |
1da177e4 | 332 | |
a3f565b1 CL |
333 | dprintk("NFS: %5u initiated direct read call " |
334 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
1da177e4 LT |
335 | data->task.tk_pid, |
336 | inode->i_sb->s_id, | |
337 | (long long)NFS_FILEID(inode), | |
338 | bytes, | |
339 | (unsigned long long)data->args.offset); | |
340 | ||
607f31e8 TM |
341 | started += bytes; |
342 | user_addr += bytes; | |
88467055 | 343 | pos += bytes; |
e9f7bee1 | 344 | /* FIXME: Remove this unnecessary math from final patch */ |
1da177e4 | 345 | pgbase += bytes; |
1da177e4 | 346 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 347 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 LT |
348 | |
349 | count -= bytes; | |
350 | } while (count != 0); | |
607f31e8 | 351 | |
607f31e8 | 352 | if (started) |
c216fd70 | 353 | return started; |
607f31e8 | 354 | return result < 0 ? (ssize_t) result : -EFAULT; |
1da177e4 LT |
355 | } |
356 | ||
19f73787 CL |
357 | static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, |
358 | const struct iovec *iov, | |
359 | unsigned long nr_segs, | |
360 | loff_t pos) | |
361 | { | |
362 | ssize_t result = -EINVAL; | |
363 | size_t requested_bytes = 0; | |
364 | unsigned long seg; | |
365 | ||
366 | get_dreq(dreq); | |
367 | ||
368 | for (seg = 0; seg < nr_segs; seg++) { | |
369 | const struct iovec *vec = &iov[seg]; | |
02fe4946 | 370 | result = nfs_direct_read_schedule_segment(dreq, vec, pos); |
19f73787 CL |
371 | if (result < 0) |
372 | break; | |
373 | requested_bytes += result; | |
374 | if ((size_t)result < vec->iov_len) | |
375 | break; | |
376 | pos += vec->iov_len; | |
377 | } | |
378 | ||
379 | if (put_dreq(dreq)) | |
380 | nfs_direct_complete(dreq); | |
381 | ||
382 | if (requested_bytes != 0) | |
383 | return 0; | |
384 | ||
385 | if (result < 0) | |
386 | return result; | |
387 | return -EIO; | |
388 | } | |
389 | ||
c216fd70 CL |
390 | static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, |
391 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 392 | { |
607f31e8 | 393 | ssize_t result = 0; |
1da177e4 | 394 | sigset_t oldset; |
99514f8f | 395 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
396 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
397 | struct nfs_direct_req *dreq; | |
398 | ||
607f31e8 | 399 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
400 | if (!dreq) |
401 | return -ENOMEM; | |
402 | ||
91d5b470 | 403 | dreq->inode = inode; |
cd3758e3 | 404 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
487b8372 CL |
405 | if (!is_sync_kiocb(iocb)) |
406 | dreq->iocb = iocb; | |
1da177e4 LT |
407 | |
408 | rpc_clnt_sigmask(clnt, &oldset); | |
c216fd70 | 409 | result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos); |
607f31e8 TM |
410 | if (!result) |
411 | result = nfs_direct_wait(dreq); | |
1da177e4 | 412 | rpc_clnt_sigunmask(clnt, &oldset); |
b4946ffb | 413 | nfs_direct_req_release(dreq); |
1da177e4 LT |
414 | |
415 | return result; | |
416 | } | |
417 | ||
fad61490 | 418 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 419 | { |
607f31e8 TM |
420 | while (!list_empty(&dreq->rewrite_list)) { |
421 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 422 | list_del(&data->pages); |
607f31e8 | 423 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
424 | nfs_writedata_release(data); |
425 | } | |
426 | } | |
1da177e4 | 427 | |
fad61490 TM |
428 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
429 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
430 | { | |
607f31e8 TM |
431 | struct inode *inode = dreq->inode; |
432 | struct list_head *p; | |
433 | struct nfs_write_data *data; | |
1da177e4 | 434 | |
fad61490 | 435 | dreq->count = 0; |
607f31e8 TM |
436 | get_dreq(dreq); |
437 | ||
438 | list_for_each(p, &dreq->rewrite_list) { | |
439 | data = list_entry(p, struct nfs_write_data, pages); | |
440 | ||
441 | get_dreq(dreq); | |
442 | ||
443 | /* | |
444 | * Reset data->res. | |
445 | */ | |
446 | nfs_fattr_init(&data->fattr); | |
447 | data->res.count = data->args.count; | |
448 | memset(&data->verf, 0, sizeof(data->verf)); | |
449 | ||
450 | /* | |
451 | * Reuse data->task; data->args should not have changed | |
452 | * since the original request was sent. | |
453 | */ | |
454 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
455 | &nfs_write_direct_ops, data); | |
456 | NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); | |
457 | ||
458 | data->task.tk_priority = RPC_PRIORITY_NORMAL; | |
459 | data->task.tk_cookie = (unsigned long) inode; | |
460 | ||
461 | /* | |
462 | * We're called via an RPC callback, so BKL is already held. | |
463 | */ | |
464 | rpc_execute(&data->task); | |
465 | ||
466 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
467 | data->task.tk_pid, | |
468 | inode->i_sb->s_id, | |
469 | (long long)NFS_FILEID(inode), | |
470 | data->args.count, | |
471 | (unsigned long long)data->args.offset); | |
472 | } | |
fedb595c | 473 | |
607f31e8 TM |
474 | if (put_dreq(dreq)) |
475 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
476 | } |
477 | ||
478 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
479 | { | |
480 | struct nfs_write_data *data = calldata; | |
481 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
482 | ||
483 | /* Call the NFS version-specific code */ | |
484 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
485 | return; | |
486 | if (unlikely(task->tk_status < 0)) { | |
60fa3f76 TM |
487 | dprintk("NFS: %5u commit failed with error %d.\n", |
488 | task->tk_pid, task->tk_status); | |
fad61490 | 489 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
60fa3f76 | 490 | } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { |
fad61490 TM |
491 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); |
492 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
493 | } |
494 | ||
fad61490 TM |
495 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
496 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
497 | } |
498 | ||
fad61490 TM |
499 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
500 | .rpc_call_done = nfs_direct_commit_result, | |
501 | .rpc_release = nfs_commit_release, | |
502 | }; | |
503 | ||
504 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 505 | { |
fad61490 | 506 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 507 | |
fad61490 | 508 | data->inode = dreq->inode; |
a8881f5a | 509 | data->cred = dreq->ctx->cred; |
1da177e4 | 510 | |
fad61490 | 511 | data->args.fh = NFS_FH(data->inode); |
607f31e8 TM |
512 | data->args.offset = 0; |
513 | data->args.count = 0; | |
fad61490 TM |
514 | data->res.count = 0; |
515 | data->res.fattr = &data->fattr; | |
516 | data->res.verf = &data->verf; | |
1da177e4 | 517 | |
fad61490 TM |
518 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
519 | &nfs_commit_direct_ops, data); | |
520 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 521 | |
fad61490 TM |
522 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
523 | data->task.tk_cookie = (unsigned long)data->inode; | |
524 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
525 | dreq->commit_data = NULL; | |
1da177e4 | 526 | |
e99170ff | 527 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 528 | |
fad61490 | 529 | rpc_execute(&data->task); |
fad61490 | 530 | } |
1da177e4 | 531 | |
fad61490 TM |
532 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
533 | { | |
534 | int flags = dreq->flags; | |
1da177e4 | 535 | |
fad61490 TM |
536 | dreq->flags = 0; |
537 | switch (flags) { | |
538 | case NFS_ODIRECT_DO_COMMIT: | |
539 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 540 | break; |
fad61490 TM |
541 | case NFS_ODIRECT_RESCHED_WRITES: |
542 | nfs_direct_write_reschedule(dreq); | |
543 | break; | |
544 | default: | |
fad61490 TM |
545 | if (dreq->commit_data != NULL) |
546 | nfs_commit_free(dreq->commit_data); | |
547 | nfs_direct_free_writedata(dreq); | |
cd9ae2b6 | 548 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
549 | nfs_direct_complete(dreq); |
550 | } | |
551 | } | |
1da177e4 | 552 | |
fad61490 TM |
553 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
554 | { | |
e9f7bee1 | 555 | dreq->commit_data = nfs_commit_alloc(); |
fad61490 TM |
556 | if (dreq->commit_data != NULL) |
557 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
558 | } | |
559 | #else | |
560 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
561 | { | |
562 | dreq->commit_data = NULL; | |
563 | } | |
1da177e4 | 564 | |
fad61490 TM |
565 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
566 | { | |
fad61490 | 567 | nfs_direct_free_writedata(dreq); |
cd9ae2b6 | 568 | nfs_zap_mapping(inode, inode->i_mapping); |
fad61490 TM |
569 | nfs_direct_complete(dreq); |
570 | } | |
571 | #endif | |
1da177e4 | 572 | |
462d5b32 | 573 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 574 | { |
462d5b32 CL |
575 | struct nfs_write_data *data = calldata; |
576 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
577 | int status = task->tk_status; | |
578 | ||
579 | if (nfs_writeback_done(task, data) != 0) | |
580 | return; | |
462d5b32 | 581 | |
15ce4a0c | 582 | spin_lock(&dreq->lock); |
1da177e4 | 583 | |
eda3cef8 | 584 | if (unlikely(status < 0)) { |
432409ee | 585 | /* An error has occurred, so we should not commit */ |
60fa3f76 | 586 | dreq->flags = 0; |
eda3cef8 | 587 | dreq->error = status; |
eda3cef8 | 588 | } |
432409ee NB |
589 | if (unlikely(dreq->error != 0)) |
590 | goto out_unlock; | |
eda3cef8 TM |
591 | |
592 | dreq->count += data->res.count; | |
1da177e4 | 593 | |
fad61490 TM |
594 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
595 | switch (dreq->flags) { | |
596 | case 0: | |
597 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
598 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 599 | break; |
fad61490 TM |
600 | case NFS_ODIRECT_DO_COMMIT: |
601 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
602 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
603 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
604 | } | |
1da177e4 | 605 | } |
1da177e4 | 606 | } |
eda3cef8 | 607 | out_unlock: |
fad61490 | 608 | spin_unlock(&dreq->lock); |
1da177e4 LT |
609 | } |
610 | ||
fad61490 TM |
611 | /* |
612 | * NB: Return the value of the first error return code. Subsequent | |
613 | * errors after the first one are ignored. | |
1da177e4 | 614 | */ |
fad61490 | 615 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 616 | { |
fad61490 TM |
617 | struct nfs_write_data *data = calldata; |
618 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 619 | |
607f31e8 TM |
620 | if (put_dreq(dreq)) |
621 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
622 | } |
623 | ||
624 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
625 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 626 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
627 | }; |
628 | ||
629 | /* | |
607f31e8 TM |
630 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
631 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
632 | * bail and stop sending more writes. Write length accounting is | |
633 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
634 | * no requests have been sent, just return an error. | |
462d5b32 | 635 | */ |
02fe4946 CL |
636 | static ssize_t nfs_direct_write_schedule_segment(struct nfs_direct_req *dreq, |
637 | const struct iovec *iov, | |
638 | loff_t pos, int sync) | |
462d5b32 | 639 | { |
a8881f5a | 640 | struct nfs_open_context *ctx = dreq->ctx; |
88be9f99 | 641 | struct inode *inode = ctx->path.dentry->d_inode; |
02fe4946 CL |
642 | unsigned long user_addr = (unsigned long)iov->iov_base; |
643 | size_t count = iov->iov_len; | |
462d5b32 | 644 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
645 | unsigned int pgbase; |
646 | int result; | |
647 | ssize_t started = 0; | |
82b145c5 | 648 | |
1da177e4 | 649 | do { |
82b145c5 | 650 | struct nfs_write_data *data; |
462d5b32 CL |
651 | size_t bytes; |
652 | ||
e9f7bee1 TM |
653 | pgbase = user_addr & ~PAGE_MASK; |
654 | bytes = min(wsize,count); | |
655 | ||
607f31e8 | 656 | result = -ENOMEM; |
8d5658c9 | 657 | data = nfs_writedata_alloc(nfs_page_array_len(pgbase, bytes)); |
607f31e8 TM |
658 | if (unlikely(!data)) |
659 | break; | |
660 | ||
607f31e8 TM |
661 | down_read(¤t->mm->mmap_sem); |
662 | result = get_user_pages(current, current->mm, user_addr, | |
663 | data->npages, 0, 0, data->pagevec, NULL); | |
664 | up_read(¤t->mm->mmap_sem); | |
749e146e CL |
665 | if (result < 0) { |
666 | nfs_writedata_release(data); | |
667 | break; | |
668 | } | |
669 | if ((unsigned)result < data->npages) { | |
d9df8d6b TM |
670 | bytes = result * PAGE_SIZE; |
671 | if (bytes <= pgbase) { | |
672 | nfs_direct_release_pages(data->pagevec, result); | |
673 | nfs_writedata_release(data); | |
674 | break; | |
675 | } | |
676 | bytes -= pgbase; | |
677 | data->npages = result; | |
607f31e8 TM |
678 | } |
679 | ||
680 | get_dreq(dreq); | |
681 | ||
fad61490 | 682 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 683 | |
607f31e8 | 684 | data->req = (struct nfs_page *) dreq; |
462d5b32 CL |
685 | data->inode = inode; |
686 | data->cred = ctx->cred; | |
687 | data->args.fh = NFS_FH(inode); | |
688 | data->args.context = ctx; | |
88467055 | 689 | data->args.offset = pos; |
462d5b32 | 690 | data->args.pgbase = pgbase; |
607f31e8 | 691 | data->args.pages = data->pagevec; |
462d5b32 CL |
692 | data->args.count = bytes; |
693 | data->res.fattr = &data->fattr; | |
694 | data->res.count = bytes; | |
47989d74 | 695 | data->res.verf = &data->verf; |
462d5b32 CL |
696 | |
697 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
698 | &nfs_write_direct_ops, data); | |
fad61490 | 699 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 700 | |
462d5b32 CL |
701 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
702 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 | 703 | |
462d5b32 | 704 | rpc_execute(&data->task); |
1da177e4 | 705 | |
a3f565b1 CL |
706 | dprintk("NFS: %5u initiated direct write call " |
707 | "(req %s/%Ld, %zu bytes @ offset %Lu)\n", | |
462d5b32 CL |
708 | data->task.tk_pid, |
709 | inode->i_sb->s_id, | |
710 | (long long)NFS_FILEID(inode), | |
711 | bytes, | |
712 | (unsigned long long)data->args.offset); | |
1da177e4 | 713 | |
607f31e8 TM |
714 | started += bytes; |
715 | user_addr += bytes; | |
88467055 | 716 | pos += bytes; |
e9f7bee1 TM |
717 | |
718 | /* FIXME: Remove this useless math from the final patch */ | |
462d5b32 | 719 | pgbase += bytes; |
462d5b32 | 720 | pgbase &= ~PAGE_MASK; |
e9f7bee1 | 721 | BUG_ON(pgbase != (user_addr & ~PAGE_MASK)); |
1da177e4 | 722 | |
462d5b32 CL |
723 | count -= bytes; |
724 | } while (count != 0); | |
607f31e8 | 725 | |
607f31e8 | 726 | if (started) |
c216fd70 | 727 | return started; |
607f31e8 | 728 | return result < 0 ? (ssize_t) result : -EFAULT; |
462d5b32 | 729 | } |
1da177e4 | 730 | |
19f73787 CL |
731 | static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, |
732 | const struct iovec *iov, | |
733 | unsigned long nr_segs, | |
734 | loff_t pos, int sync) | |
735 | { | |
736 | ssize_t result = 0; | |
737 | size_t requested_bytes = 0; | |
738 | unsigned long seg; | |
739 | ||
740 | get_dreq(dreq); | |
741 | ||
742 | for (seg = 0; seg < nr_segs; seg++) { | |
743 | const struct iovec *vec = &iov[seg]; | |
02fe4946 CL |
744 | result = nfs_direct_write_schedule_segment(dreq, vec, |
745 | pos, sync); | |
19f73787 CL |
746 | if (result < 0) |
747 | break; | |
748 | requested_bytes += result; | |
749 | if ((size_t)result < vec->iov_len) | |
750 | break; | |
751 | pos += vec->iov_len; | |
752 | } | |
753 | ||
754 | if (put_dreq(dreq)) | |
755 | nfs_direct_write_complete(dreq, dreq->inode); | |
756 | ||
757 | if (requested_bytes != 0) | |
758 | return 0; | |
759 | ||
760 | if (result < 0) | |
761 | return result; | |
762 | return -EIO; | |
763 | } | |
764 | ||
c216fd70 CL |
765 | static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, |
766 | unsigned long nr_segs, loff_t pos, | |
767 | size_t count) | |
462d5b32 | 768 | { |
607f31e8 | 769 | ssize_t result = 0; |
462d5b32 | 770 | sigset_t oldset; |
c89f2ee5 | 771 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
772 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
773 | struct nfs_direct_req *dreq; | |
fad61490 TM |
774 | size_t wsize = NFS_SERVER(inode)->wsize; |
775 | int sync = 0; | |
1da177e4 | 776 | |
607f31e8 | 777 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
778 | if (!dreq) |
779 | return -ENOMEM; | |
607f31e8 TM |
780 | nfs_alloc_commit_data(dreq); |
781 | ||
fad61490 TM |
782 | if (dreq->commit_data == NULL || count < wsize) |
783 | sync = FLUSH_STABLE; | |
1da177e4 | 784 | |
c89f2ee5 | 785 | dreq->inode = inode; |
cd3758e3 | 786 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
c89f2ee5 CL |
787 | if (!is_sync_kiocb(iocb)) |
788 | dreq->iocb = iocb; | |
1da177e4 | 789 | |
462d5b32 | 790 | rpc_clnt_sigmask(clnt, &oldset); |
c216fd70 | 791 | result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, sync); |
607f31e8 TM |
792 | if (!result) |
793 | result = nfs_direct_wait(dreq); | |
462d5b32 | 794 | rpc_clnt_sigunmask(clnt, &oldset); |
b4946ffb | 795 | nfs_direct_req_release(dreq); |
1da177e4 | 796 | |
1da177e4 LT |
797 | return result; |
798 | } | |
799 | ||
800 | /** | |
801 | * nfs_file_direct_read - file direct read operation for NFS files | |
802 | * @iocb: target I/O control block | |
027445c3 BP |
803 | * @iov: vector of user buffers into which to read data |
804 | * @nr_segs: size of iov vector | |
88467055 | 805 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
806 | * |
807 | * We use this function for direct reads instead of calling | |
808 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
809 | * the request starts before the end of the file. For that check | |
810 | * to work, we must generate a GETATTR before each direct read, and | |
811 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 812 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
813 | * to do all reads the application wants, and the server will take |
814 | * care of managing the end of file boundary. | |
88467055 | 815 | * |
1da177e4 LT |
816 | * This function also eliminates unnecessarily updating the file's |
817 | * atime locally, as the NFS server sets the file's atime, and this | |
818 | * client must read the updated atime from the server back into its | |
819 | * cache. | |
820 | */ | |
027445c3 BP |
821 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
822 | unsigned long nr_segs, loff_t pos) | |
1da177e4 LT |
823 | { |
824 | ssize_t retval = -EINVAL; | |
1da177e4 | 825 | struct file *file = iocb->ki_filp; |
1da177e4 | 826 | struct address_space *mapping = file->f_mapping; |
c216fd70 CL |
827 | size_t count; |
828 | ||
829 | count = iov_length(iov, nr_segs); | |
830 | nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); | |
1da177e4 | 831 | |
c216fd70 | 832 | dprintk("nfs: direct read(%s/%s, %zd@%Ld)\n", |
01cce933 JJS |
833 | file->f_path.dentry->d_parent->d_name.name, |
834 | file->f_path.dentry->d_name.name, | |
c216fd70 | 835 | count, (long long) pos); |
1da177e4 | 836 | |
1da177e4 LT |
837 | retval = 0; |
838 | if (!count) | |
839 | goto out; | |
840 | ||
29884df0 TM |
841 | retval = nfs_sync_mapping(mapping); |
842 | if (retval) | |
843 | goto out; | |
1da177e4 | 844 | |
c216fd70 | 845 | retval = nfs_direct_read(iocb, iov, nr_segs, pos); |
1da177e4 | 846 | if (retval > 0) |
0cdd80d0 | 847 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
848 | |
849 | out: | |
850 | return retval; | |
851 | } | |
852 | ||
853 | /** | |
854 | * nfs_file_direct_write - file direct write operation for NFS files | |
855 | * @iocb: target I/O control block | |
027445c3 BP |
856 | * @iov: vector of user buffers from which to write data |
857 | * @nr_segs: size of iov vector | |
88467055 | 858 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
859 | * |
860 | * We use this function for direct writes instead of calling | |
861 | * generic_file_aio_write() in order to avoid taking the inode | |
862 | * semaphore and updating the i_size. The NFS server will set | |
863 | * the new i_size and this client must read the updated size | |
864 | * back into its cache. We let the server do generic write | |
865 | * parameter checking and report problems. | |
866 | * | |
867 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
868 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
869 | * | |
870 | * We eliminate local atime updates, see direct read above. | |
871 | * | |
872 | * We avoid unnecessary page cache invalidations for normal cached | |
873 | * readers of this file. | |
874 | * | |
875 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
876 | * is no atomic O_APPEND write facility in the NFS protocol. | |
877 | */ | |
027445c3 BP |
878 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
879 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 880 | { |
070ea602 | 881 | ssize_t retval = -EINVAL; |
1da177e4 | 882 | struct file *file = iocb->ki_filp; |
1da177e4 | 883 | struct address_space *mapping = file->f_mapping; |
c216fd70 | 884 | size_t count; |
1da177e4 | 885 | |
c216fd70 CL |
886 | count = iov_length(iov, nr_segs); |
887 | nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); | |
888 | ||
889 | dfprintk(VFS, "nfs: direct write(%s/%s, %zd@%Ld)\n", | |
01cce933 JJS |
890 | file->f_path.dentry->d_parent->d_name.name, |
891 | file->f_path.dentry->d_name.name, | |
c216fd70 | 892 | count, (long long) pos); |
027445c3 | 893 | |
ce1a8e67 CL |
894 | retval = generic_write_checks(file, &pos, &count, 0); |
895 | if (retval) | |
1da177e4 | 896 | goto out; |
b9148c6b CL |
897 | if (!count) |
898 | goto out; /* return 0 */ | |
ce1a8e67 CL |
899 | |
900 | retval = -EINVAL; | |
901 | if ((ssize_t) count < 0) | |
1da177e4 | 902 | goto out; |
1da177e4 LT |
903 | retval = 0; |
904 | if (!count) | |
905 | goto out; | |
ce1a8e67 | 906 | |
29884df0 TM |
907 | retval = nfs_sync_mapping(mapping); |
908 | if (retval) | |
909 | goto out; | |
1da177e4 | 910 | |
c216fd70 | 911 | retval = nfs_direct_write(iocb, iov, nr_segs, pos, count); |
9eafa8cc | 912 | |
1da177e4 | 913 | if (retval > 0) |
ce1a8e67 | 914 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
915 | |
916 | out: | |
917 | return retval; | |
918 | } | |
919 | ||
88467055 CL |
920 | /** |
921 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
922 | * | |
923 | */ | |
f7b422b1 | 924 | int __init nfs_init_directcache(void) |
1da177e4 LT |
925 | { |
926 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
927 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
928 | 0, (SLAB_RECLAIM_ACCOUNT| |
929 | SLAB_MEM_SPREAD), | |
20c2df83 | 930 | NULL); |
1da177e4 LT |
931 | if (nfs_direct_cachep == NULL) |
932 | return -ENOMEM; | |
933 | ||
934 | return 0; | |
935 | } | |
936 | ||
88467055 | 937 | /** |
f7b422b1 | 938 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
939 | * |
940 | */ | |
266bee88 | 941 | void nfs_destroy_directcache(void) |
1da177e4 | 942 | { |
1a1d92c1 | 943 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 944 | } |