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 | ||
41 | #include <linux/config.h> | |
42 | #include <linux/errno.h> | |
43 | #include <linux/sched.h> | |
44 | #include <linux/kernel.h> | |
45 | #include <linux/smp_lock.h> | |
46 | #include <linux/file.h> | |
47 | #include <linux/pagemap.h> | |
48 | #include <linux/kref.h> | |
49 | ||
50 | #include <linux/nfs_fs.h> | |
51 | #include <linux/nfs_page.h> | |
52 | #include <linux/sunrpc/clnt.h> | |
53 | ||
54 | #include <asm/system.h> | |
55 | #include <asm/uaccess.h> | |
56 | #include <asm/atomic.h> | |
57 | ||
91d5b470 CL |
58 | #include "iostat.h" |
59 | ||
1da177e4 | 60 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 LT |
61 | |
62 | static kmem_cache_t *nfs_direct_cachep; | |
63 | ||
64 | /* | |
65 | * This represents a set of asynchronous requests that we're waiting on | |
66 | */ | |
67 | struct nfs_direct_req { | |
68 | struct kref kref; /* release manager */ | |
15ce4a0c CL |
69 | |
70 | /* I/O parameters */ | |
a8881f5a | 71 | struct nfs_open_context *ctx; /* file open context info */ |
99514f8f | 72 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 73 | struct inode * inode; /* target file of i/o */ |
15ce4a0c CL |
74 | |
75 | /* completion state */ | |
b1c5921c | 76 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 77 | spinlock_t lock; /* protect completion state */ |
15ce4a0c | 78 | ssize_t count, /* bytes actually processed */ |
1da177e4 | 79 | error; /* any reported error */ |
d72b7a6b | 80 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
81 | |
82 | /* commit state */ | |
82b145c5 | 83 | struct list_head rewrite_list; /* saved nfs_write_data structs */ |
fad61490 TM |
84 | struct nfs_write_data * commit_data; /* special write_data for commits */ |
85 | int flags; | |
86 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ | |
87 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
88 | struct nfs_writeverf verf; /* unstable write verifier */ | |
1da177e4 LT |
89 | }; |
90 | ||
fad61490 | 91 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); |
fedb595c | 92 | static const struct rpc_call_ops nfs_write_direct_ops; |
1da177e4 | 93 | |
b1c5921c CL |
94 | static inline void get_dreq(struct nfs_direct_req *dreq) |
95 | { | |
96 | atomic_inc(&dreq->io_count); | |
97 | } | |
98 | ||
99 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
100 | { | |
101 | return atomic_dec_and_test(&dreq->io_count); | |
102 | } | |
103 | ||
06cf6f2e CL |
104 | /* |
105 | * "size" is never larger than rsize or wsize. | |
106 | */ | |
107 | static inline int nfs_direct_count_pages(unsigned long user_addr, size_t size) | |
108 | { | |
109 | int page_count; | |
110 | ||
111 | page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
112 | page_count -= user_addr >> PAGE_SHIFT; | |
113 | BUG_ON(page_count < 0); | |
114 | ||
115 | return page_count; | |
116 | } | |
117 | ||
82b145c5 CL |
118 | static inline unsigned int nfs_max_pages(unsigned int size) |
119 | { | |
120 | return (size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; | |
121 | } | |
122 | ||
1da177e4 | 123 | /** |
b8a32e2b CL |
124 | * nfs_direct_IO - NFS address space operation for direct I/O |
125 | * @rw: direction (read or write) | |
126 | * @iocb: target I/O control block | |
127 | * @iov: array of vectors that define I/O buffer | |
128 | * @pos: offset in file to begin the operation | |
129 | * @nr_segs: size of iovec array | |
130 | * | |
131 | * The presence of this routine in the address space ops vector means | |
132 | * the NFS client supports direct I/O. However, we shunt off direct | |
133 | * read and write requests before the VFS gets them, so this method | |
134 | * should never be called. | |
1da177e4 | 135 | */ |
b8a32e2b CL |
136 | ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) |
137 | { | |
b8a32e2b | 138 | dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", |
e99170ff TM |
139 | iocb->ki_filp->f_dentry->d_name.name, |
140 | (long long) pos, nr_segs); | |
b8a32e2b CL |
141 | |
142 | return -EINVAL; | |
143 | } | |
144 | ||
9c93ab7d | 145 | static void nfs_direct_dirty_pages(struct page **pages, int npages) |
6b45d858 TM |
146 | { |
147 | int i; | |
148 | for (i = 0; i < npages; i++) { | |
149 | struct page *page = pages[i]; | |
9c93ab7d | 150 | if (!PageCompound(page)) |
6b45d858 | 151 | set_page_dirty_lock(page); |
6b45d858 | 152 | } |
9c93ab7d CL |
153 | } |
154 | ||
155 | static void nfs_direct_release_pages(struct page **pages, int npages) | |
156 | { | |
157 | int i; | |
158 | for (i = 0; i < npages; i++) | |
159 | page_cache_release(pages[i]); | |
6b45d858 TM |
160 | } |
161 | ||
93619e59 | 162 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 163 | { |
93619e59 CL |
164 | struct nfs_direct_req *dreq; |
165 | ||
166 | dreq = kmem_cache_alloc(nfs_direct_cachep, SLAB_KERNEL); | |
167 | if (!dreq) | |
168 | return NULL; | |
169 | ||
170 | kref_init(&dreq->kref); | |
82b145c5 | 171 | kref_get(&dreq->kref); |
d72b7a6b | 172 | init_completion(&dreq->completion); |
fad61490 | 173 | INIT_LIST_HEAD(&dreq->rewrite_list); |
93619e59 | 174 | dreq->iocb = NULL; |
a8881f5a | 175 | dreq->ctx = NULL; |
15ce4a0c | 176 | spin_lock_init(&dreq->lock); |
b1c5921c | 177 | atomic_set(&dreq->io_count, 0); |
15ce4a0c CL |
178 | dreq->count = 0; |
179 | dreq->error = 0; | |
fad61490 | 180 | dreq->flags = 0; |
93619e59 CL |
181 | |
182 | return dreq; | |
1da177e4 LT |
183 | } |
184 | ||
1da177e4 LT |
185 | static void nfs_direct_req_release(struct kref *kref) |
186 | { | |
187 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a TM |
188 | |
189 | if (dreq->ctx != NULL) | |
190 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
191 | kmem_cache_free(nfs_direct_cachep, dreq); |
192 | } | |
193 | ||
bc0fb201 CL |
194 | /* |
195 | * Collects and returns the final error value/byte-count. | |
196 | */ | |
197 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
198 | { | |
15ce4a0c | 199 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
200 | |
201 | /* Async requests don't wait here */ | |
202 | if (dreq->iocb) | |
203 | goto out; | |
204 | ||
d72b7a6b | 205 | result = wait_for_completion_interruptible(&dreq->completion); |
bc0fb201 CL |
206 | |
207 | if (!result) | |
15ce4a0c | 208 | result = dreq->error; |
bc0fb201 | 209 | if (!result) |
15ce4a0c | 210 | result = dreq->count; |
bc0fb201 CL |
211 | |
212 | out: | |
213 | kref_put(&dreq->kref, nfs_direct_req_release); | |
214 | return (ssize_t) result; | |
215 | } | |
216 | ||
63ab46ab | 217 | /* |
06cf6f2e CL |
218 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
219 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
220 | */ |
221 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
222 | { | |
63ab46ab | 223 | if (dreq->iocb) { |
15ce4a0c | 224 | long res = (long) dreq->error; |
63ab46ab | 225 | if (!res) |
15ce4a0c | 226 | res = (long) dreq->count; |
63ab46ab | 227 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
228 | } |
229 | complete_all(&dreq->completion); | |
63ab46ab CL |
230 | |
231 | kref_put(&dreq->kref, nfs_direct_req_release); | |
232 | } | |
233 | ||
06cf6f2e CL |
234 | /* |
235 | * We must hold a reference to all the pages in this direct read request | |
236 | * until the RPCs complete. This could be long *after* we are woken up in | |
237 | * nfs_direct_wait (for instance, if someone hits ^C on a slow server). | |
238 | */ | |
ec06c096 | 239 | static void nfs_direct_read_result(struct rpc_task *task, void *calldata) |
1da177e4 | 240 | { |
ec06c096 | 241 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
242 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; |
243 | ||
ec06c096 TM |
244 | if (nfs_readpage_result(task, data) != 0) |
245 | return; | |
15ce4a0c | 246 | |
06cf6f2e CL |
247 | nfs_direct_dirty_pages(data->pagevec, data->npages); |
248 | nfs_direct_release_pages(data->pagevec, data->npages); | |
249 | ||
15ce4a0c CL |
250 | spin_lock(&dreq->lock); |
251 | ||
ec06c096 | 252 | if (likely(task->tk_status >= 0)) |
15ce4a0c | 253 | dreq->count += data->res.count; |
1da177e4 | 254 | else |
15ce4a0c | 255 | dreq->error = task->tk_status; |
1da177e4 | 256 | |
15ce4a0c | 257 | spin_unlock(&dreq->lock); |
b1c5921c | 258 | |
06cf6f2e | 259 | if (put_dreq(dreq)) |
b1c5921c | 260 | nfs_direct_complete(dreq); |
1da177e4 LT |
261 | } |
262 | ||
ec06c096 TM |
263 | static const struct rpc_call_ops nfs_read_direct_ops = { |
264 | .rpc_call_done = nfs_direct_read_result, | |
265 | .rpc_release = nfs_readdata_release, | |
266 | }; | |
267 | ||
d4cc948b | 268 | /* |
82b145c5 CL |
269 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
270 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
271 | * bail and stop sending more reads. Read length accounting is | |
272 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
273 | * no requests have been sent, just return an error. | |
1da177e4 | 274 | */ |
06cf6f2e | 275 | static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 276 | { |
a8881f5a TM |
277 | struct nfs_open_context *ctx = dreq->ctx; |
278 | struct inode *inode = ctx->dentry->d_inode; | |
5dd602f2 | 279 | size_t rsize = NFS_SERVER(inode)->rsize; |
82b145c5 | 280 | unsigned int rpages = nfs_max_pages(rsize); |
06cf6f2e CL |
281 | unsigned int pgbase; |
282 | int result; | |
283 | ssize_t started = 0; | |
82b145c5 CL |
284 | |
285 | get_dreq(dreq); | |
1da177e4 | 286 | |
51a7bc6c | 287 | pgbase = user_addr & ~PAGE_MASK; |
1da177e4 | 288 | do { |
82b145c5 | 289 | struct nfs_read_data *data; |
5dd602f2 | 290 | size_t bytes; |
1da177e4 | 291 | |
82b145c5 CL |
292 | result = -ENOMEM; |
293 | data = nfs_readdata_alloc(rpages); | |
294 | if (unlikely(!data)) | |
295 | break; | |
296 | ||
1da177e4 LT |
297 | bytes = rsize; |
298 | if (count < rsize) | |
299 | bytes = count; | |
300 | ||
06cf6f2e CL |
301 | data->npages = nfs_direct_count_pages(user_addr, bytes); |
302 | down_read(¤t->mm->mmap_sem); | |
303 | result = get_user_pages(current, current->mm, user_addr, | |
304 | data->npages, 1, 0, data->pagevec, NULL); | |
305 | up_read(¤t->mm->mmap_sem); | |
82b145c5 CL |
306 | if (unlikely(result < data->npages)) { |
307 | if (result > 0) | |
308 | nfs_direct_release_pages(data->pagevec, result); | |
309 | nfs_readdata_release(data); | |
310 | break; | |
311 | } | |
06cf6f2e | 312 | |
82b145c5 CL |
313 | get_dreq(dreq); |
314 | ||
315 | data->req = (struct nfs_page *) dreq; | |
1da177e4 LT |
316 | data->inode = inode; |
317 | data->cred = ctx->cred; | |
318 | data->args.fh = NFS_FH(inode); | |
319 | data->args.context = ctx; | |
88467055 | 320 | data->args.offset = pos; |
1da177e4 | 321 | data->args.pgbase = pgbase; |
06cf6f2e | 322 | data->args.pages = data->pagevec; |
1da177e4 LT |
323 | data->args.count = bytes; |
324 | data->res.fattr = &data->fattr; | |
325 | data->res.eof = 0; | |
326 | data->res.count = bytes; | |
327 | ||
ec06c096 TM |
328 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
329 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
330 | NFS_PROTO(inode)->read_setup(data); |
331 | ||
332 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
333 | |
334 | lock_kernel(); | |
335 | rpc_execute(&data->task); | |
336 | unlock_kernel(); | |
337 | ||
606bbba0 | 338 | dfprintk(VFS, "NFS: %5u initiated direct read call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
1da177e4 LT |
339 | data->task.tk_pid, |
340 | inode->i_sb->s_id, | |
341 | (long long)NFS_FILEID(inode), | |
342 | bytes, | |
343 | (unsigned long long)data->args.offset); | |
344 | ||
06cf6f2e CL |
345 | started += bytes; |
346 | user_addr += bytes; | |
88467055 | 347 | pos += bytes; |
1da177e4 | 348 | pgbase += bytes; |
1da177e4 LT |
349 | pgbase &= ~PAGE_MASK; |
350 | ||
351 | count -= bytes; | |
352 | } while (count != 0); | |
06cf6f2e | 353 | |
82b145c5 CL |
354 | if (put_dreq(dreq)) |
355 | nfs_direct_complete(dreq); | |
06cf6f2e CL |
356 | |
357 | if (started) | |
358 | return 0; | |
359 | return result < 0 ? (ssize_t) result : -EFAULT; | |
1da177e4 LT |
360 | } |
361 | ||
06cf6f2e | 362 | static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
1da177e4 | 363 | { |
82b145c5 | 364 | ssize_t result = 0; |
1da177e4 | 365 | sigset_t oldset; |
99514f8f | 366 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
367 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
368 | struct nfs_direct_req *dreq; | |
369 | ||
82b145c5 | 370 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
371 | if (!dreq) |
372 | return -ENOMEM; | |
373 | ||
91d5b470 | 374 | dreq->inode = inode; |
a8881f5a | 375 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
487b8372 CL |
376 | if (!is_sync_kiocb(iocb)) |
377 | dreq->iocb = iocb; | |
1da177e4 | 378 | |
91d5b470 | 379 | nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); |
1da177e4 | 380 | rpc_clnt_sigmask(clnt, &oldset); |
06cf6f2e CL |
381 | result = nfs_direct_read_schedule(dreq, user_addr, count, pos); |
382 | if (!result) | |
383 | result = nfs_direct_wait(dreq); | |
1da177e4 LT |
384 | rpc_clnt_sigunmask(clnt, &oldset); |
385 | ||
386 | return result; | |
387 | } | |
388 | ||
fad61490 | 389 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 390 | { |
82b145c5 CL |
391 | while (!list_empty(&dreq->rewrite_list)) { |
392 | struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); | |
fad61490 | 393 | list_del(&data->pages); |
06cf6f2e | 394 | nfs_direct_release_pages(data->pagevec, data->npages); |
fad61490 TM |
395 | nfs_writedata_release(data); |
396 | } | |
397 | } | |
1da177e4 | 398 | |
fad61490 TM |
399 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
400 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
401 | { | |
fedb595c CL |
402 | struct inode *inode = dreq->inode; |
403 | struct list_head *p; | |
404 | struct nfs_write_data *data; | |
1da177e4 | 405 | |
fad61490 | 406 | dreq->count = 0; |
fedb595c CL |
407 | get_dreq(dreq); |
408 | ||
409 | list_for_each(p, &dreq->rewrite_list) { | |
410 | data = list_entry(p, struct nfs_write_data, pages); | |
411 | ||
412 | get_dreq(dreq); | |
413 | ||
414 | /* | |
415 | * Reset data->res. | |
416 | */ | |
417 | nfs_fattr_init(&data->fattr); | |
418 | data->res.count = data->args.count; | |
419 | memset(&data->verf, 0, sizeof(data->verf)); | |
420 | ||
421 | /* | |
422 | * Reuse data->task; data->args should not have changed | |
423 | * since the original request was sent. | |
424 | */ | |
425 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
426 | &nfs_write_direct_ops, data); | |
427 | NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); | |
428 | ||
429 | data->task.tk_priority = RPC_PRIORITY_NORMAL; | |
430 | data->task.tk_cookie = (unsigned long) inode; | |
fad61490 | 431 | |
fedb595c CL |
432 | /* |
433 | * We're called via an RPC callback, so BKL is already held. | |
434 | */ | |
435 | rpc_execute(&data->task); | |
436 | ||
437 | dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", | |
438 | data->task.tk_pid, | |
439 | inode->i_sb->s_id, | |
440 | (long long)NFS_FILEID(inode), | |
441 | data->args.count, | |
442 | (unsigned long long)data->args.offset); | |
443 | } | |
444 | ||
445 | if (put_dreq(dreq)) | |
446 | nfs_direct_write_complete(dreq, inode); | |
fad61490 TM |
447 | } |
448 | ||
449 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
450 | { | |
451 | struct nfs_write_data *data = calldata; | |
452 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
453 | ||
454 | /* Call the NFS version-specific code */ | |
455 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
456 | return; | |
457 | if (unlikely(task->tk_status < 0)) { | |
458 | dreq->error = task->tk_status; | |
459 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
460 | } | |
461 | if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { | |
462 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); | |
463 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
464 | } |
465 | ||
fad61490 TM |
466 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
467 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
468 | } |
469 | ||
fad61490 TM |
470 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
471 | .rpc_call_done = nfs_direct_commit_result, | |
472 | .rpc_release = nfs_commit_release, | |
473 | }; | |
474 | ||
475 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 476 | { |
fad61490 | 477 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 478 | |
fad61490 | 479 | data->inode = dreq->inode; |
a8881f5a | 480 | data->cred = dreq->ctx->cred; |
1da177e4 | 481 | |
fad61490 | 482 | data->args.fh = NFS_FH(data->inode); |
51a7bc6c CL |
483 | data->args.offset = 0; |
484 | data->args.count = 0; | |
fad61490 TM |
485 | data->res.count = 0; |
486 | data->res.fattr = &data->fattr; | |
487 | data->res.verf = &data->verf; | |
1da177e4 | 488 | |
fad61490 TM |
489 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
490 | &nfs_commit_direct_ops, data); | |
491 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 492 | |
fad61490 TM |
493 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
494 | data->task.tk_cookie = (unsigned long)data->inode; | |
495 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
496 | dreq->commit_data = NULL; | |
1da177e4 | 497 | |
e99170ff | 498 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 499 | |
fad61490 TM |
500 | lock_kernel(); |
501 | rpc_execute(&data->task); | |
502 | unlock_kernel(); | |
503 | } | |
1da177e4 | 504 | |
fad61490 TM |
505 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
506 | { | |
507 | int flags = dreq->flags; | |
1da177e4 | 508 | |
fad61490 TM |
509 | dreq->flags = 0; |
510 | switch (flags) { | |
511 | case NFS_ODIRECT_DO_COMMIT: | |
512 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 513 | break; |
fad61490 TM |
514 | case NFS_ODIRECT_RESCHED_WRITES: |
515 | nfs_direct_write_reschedule(dreq); | |
516 | break; | |
517 | default: | |
518 | nfs_end_data_update(inode); | |
519 | if (dreq->commit_data != NULL) | |
520 | nfs_commit_free(dreq->commit_data); | |
521 | nfs_direct_free_writedata(dreq); | |
522 | nfs_direct_complete(dreq); | |
523 | } | |
524 | } | |
1da177e4 | 525 | |
fad61490 TM |
526 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
527 | { | |
528 | dreq->commit_data = nfs_commit_alloc(0); | |
529 | if (dreq->commit_data != NULL) | |
530 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
531 | } | |
532 | #else | |
533 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
534 | { | |
535 | dreq->commit_data = NULL; | |
536 | } | |
1da177e4 | 537 | |
fad61490 TM |
538 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
539 | { | |
540 | nfs_end_data_update(inode); | |
541 | nfs_direct_free_writedata(dreq); | |
542 | nfs_direct_complete(dreq); | |
543 | } | |
544 | #endif | |
1da177e4 | 545 | |
462d5b32 | 546 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 547 | { |
462d5b32 CL |
548 | struct nfs_write_data *data = calldata; |
549 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
550 | int status = task->tk_status; | |
551 | ||
552 | if (nfs_writeback_done(task, data) != 0) | |
553 | return; | |
462d5b32 | 554 | |
15ce4a0c | 555 | spin_lock(&dreq->lock); |
1da177e4 | 556 | |
462d5b32 | 557 | if (likely(status >= 0)) |
15ce4a0c | 558 | dreq->count += data->res.count; |
462d5b32 | 559 | else |
fad61490 | 560 | dreq->error = task->tk_status; |
1da177e4 | 561 | |
fad61490 TM |
562 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
563 | switch (dreq->flags) { | |
564 | case 0: | |
565 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
566 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 567 | break; |
fad61490 TM |
568 | case NFS_ODIRECT_DO_COMMIT: |
569 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
570 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
571 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
572 | } | |
1da177e4 | 573 | } |
1da177e4 | 574 | } |
fad61490 TM |
575 | |
576 | spin_unlock(&dreq->lock); | |
1da177e4 LT |
577 | } |
578 | ||
fad61490 TM |
579 | /* |
580 | * NB: Return the value of the first error return code. Subsequent | |
581 | * errors after the first one are ignored. | |
1da177e4 | 582 | */ |
fad61490 | 583 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 584 | { |
fad61490 TM |
585 | struct nfs_write_data *data = calldata; |
586 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 587 | |
b1c5921c CL |
588 | if (put_dreq(dreq)) |
589 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
590 | } |
591 | ||
592 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
593 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 594 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
595 | }; |
596 | ||
597 | /* | |
82b145c5 CL |
598 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
599 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
600 | * bail and stop sending more writes. Write length accounting is | |
601 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
602 | * no requests have been sent, just return an error. | |
462d5b32 | 603 | */ |
06cf6f2e | 604 | 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 | 605 | { |
a8881f5a TM |
606 | struct nfs_open_context *ctx = dreq->ctx; |
607 | struct inode *inode = ctx->dentry->d_inode; | |
462d5b32 | 608 | size_t wsize = NFS_SERVER(inode)->wsize; |
82b145c5 | 609 | unsigned int wpages = nfs_max_pages(wsize); |
06cf6f2e CL |
610 | unsigned int pgbase; |
611 | int result; | |
612 | ssize_t started = 0; | |
82b145c5 CL |
613 | |
614 | get_dreq(dreq); | |
1da177e4 | 615 | |
51a7bc6c | 616 | pgbase = user_addr & ~PAGE_MASK; |
1da177e4 | 617 | do { |
82b145c5 | 618 | struct nfs_write_data *data; |
462d5b32 CL |
619 | size_t bytes; |
620 | ||
82b145c5 CL |
621 | result = -ENOMEM; |
622 | data = nfs_writedata_alloc(wpages); | |
623 | if (unlikely(!data)) | |
624 | break; | |
625 | ||
462d5b32 CL |
626 | bytes = wsize; |
627 | if (count < wsize) | |
628 | bytes = count; | |
629 | ||
06cf6f2e CL |
630 | data->npages = nfs_direct_count_pages(user_addr, bytes); |
631 | down_read(¤t->mm->mmap_sem); | |
632 | result = get_user_pages(current, current->mm, user_addr, | |
633 | data->npages, 0, 0, data->pagevec, NULL); | |
634 | up_read(¤t->mm->mmap_sem); | |
82b145c5 CL |
635 | if (unlikely(result < data->npages)) { |
636 | if (result > 0) | |
637 | nfs_direct_release_pages(data->pagevec, result); | |
638 | nfs_writedata_release(data); | |
639 | break; | |
640 | } | |
641 | ||
642 | get_dreq(dreq); | |
06cf6f2e | 643 | |
fad61490 | 644 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 | 645 | |
82b145c5 | 646 | data->req = (struct nfs_page *) dreq; |
462d5b32 CL |
647 | data->inode = inode; |
648 | data->cred = ctx->cred; | |
649 | data->args.fh = NFS_FH(inode); | |
650 | data->args.context = ctx; | |
88467055 | 651 | data->args.offset = pos; |
462d5b32 | 652 | data->args.pgbase = pgbase; |
06cf6f2e | 653 | data->args.pages = data->pagevec; |
462d5b32 CL |
654 | data->args.count = bytes; |
655 | data->res.fattr = &data->fattr; | |
656 | data->res.count = bytes; | |
47989d74 | 657 | data->res.verf = &data->verf; |
462d5b32 CL |
658 | |
659 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
660 | &nfs_write_direct_ops, data); | |
fad61490 | 661 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 662 | |
462d5b32 CL |
663 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
664 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
665 | |
666 | lock_kernel(); | |
462d5b32 | 667 | rpc_execute(&data->task); |
1da177e4 LT |
668 | unlock_kernel(); |
669 | ||
606bbba0 | 670 | dfprintk(VFS, "NFS: %5u initiated direct write call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
462d5b32 CL |
671 | data->task.tk_pid, |
672 | inode->i_sb->s_id, | |
673 | (long long)NFS_FILEID(inode), | |
674 | bytes, | |
675 | (unsigned long long)data->args.offset); | |
1da177e4 | 676 | |
06cf6f2e CL |
677 | started += bytes; |
678 | user_addr += bytes; | |
88467055 | 679 | pos += bytes; |
462d5b32 | 680 | pgbase += bytes; |
462d5b32 | 681 | pgbase &= ~PAGE_MASK; |
1da177e4 | 682 | |
462d5b32 CL |
683 | count -= bytes; |
684 | } while (count != 0); | |
06cf6f2e | 685 | |
82b145c5 CL |
686 | if (put_dreq(dreq)) |
687 | nfs_direct_write_complete(dreq, inode); | |
06cf6f2e CL |
688 | |
689 | if (started) | |
690 | return 0; | |
691 | return result < 0 ? (ssize_t) result : -EFAULT; | |
462d5b32 | 692 | } |
1da177e4 | 693 | |
06cf6f2e | 694 | static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos) |
462d5b32 | 695 | { |
82b145c5 | 696 | ssize_t result = 0; |
462d5b32 | 697 | sigset_t oldset; |
c89f2ee5 | 698 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
699 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
700 | struct nfs_direct_req *dreq; | |
fad61490 TM |
701 | size_t wsize = NFS_SERVER(inode)->wsize; |
702 | int sync = 0; | |
1da177e4 | 703 | |
82b145c5 | 704 | dreq = nfs_direct_req_alloc(); |
462d5b32 CL |
705 | if (!dreq) |
706 | return -ENOMEM; | |
82b145c5 CL |
707 | nfs_alloc_commit_data(dreq); |
708 | ||
fad61490 TM |
709 | if (dreq->commit_data == NULL || count < wsize) |
710 | sync = FLUSH_STABLE; | |
1da177e4 | 711 | |
c89f2ee5 | 712 | dreq->inode = inode; |
a8881f5a | 713 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
c89f2ee5 CL |
714 | if (!is_sync_kiocb(iocb)) |
715 | dreq->iocb = iocb; | |
1da177e4 | 716 | |
47989d74 CL |
717 | nfs_add_stats(inode, NFSIOS_DIRECTWRITTENBYTES, count); |
718 | ||
462d5b32 | 719 | nfs_begin_data_update(inode); |
1da177e4 | 720 | |
462d5b32 | 721 | rpc_clnt_sigmask(clnt, &oldset); |
06cf6f2e CL |
722 | result = nfs_direct_write_schedule(dreq, user_addr, count, pos, sync); |
723 | if (!result) | |
724 | result = nfs_direct_wait(dreq); | |
462d5b32 | 725 | rpc_clnt_sigunmask(clnt, &oldset); |
1da177e4 | 726 | |
1da177e4 LT |
727 | return result; |
728 | } | |
729 | ||
730 | /** | |
731 | * nfs_file_direct_read - file direct read operation for NFS files | |
732 | * @iocb: target I/O control block | |
733 | * @buf: user's buffer into which to read data | |
88467055 CL |
734 | * @count: number of bytes to read |
735 | * @pos: byte offset in file where reading starts | |
1da177e4 LT |
736 | * |
737 | * We use this function for direct reads instead of calling | |
738 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
739 | * the request starts before the end of the file. For that check | |
740 | * to work, we must generate a GETATTR before each direct read, and | |
741 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 742 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
743 | * to do all reads the application wants, and the server will take |
744 | * care of managing the end of file boundary. | |
88467055 | 745 | * |
1da177e4 LT |
746 | * This function also eliminates unnecessarily updating the file's |
747 | * atime locally, as the NFS server sets the file's atime, and this | |
748 | * client must read the updated atime from the server back into its | |
749 | * cache. | |
750 | */ | |
d4cc948b | 751 | ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos) |
1da177e4 LT |
752 | { |
753 | ssize_t retval = -EINVAL; | |
1da177e4 | 754 | struct file *file = iocb->ki_filp; |
1da177e4 | 755 | struct address_space *mapping = file->f_mapping; |
1da177e4 | 756 | |
ce1a8e67 | 757 | dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n", |
0bbacc40 CL |
758 | file->f_dentry->d_parent->d_name.name, |
759 | file->f_dentry->d_name.name, | |
ce1a8e67 | 760 | (unsigned long) count, (long long) pos); |
1da177e4 | 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 | |
06cf6f2e | 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 | |
786 | * @buf: user's buffer from which to write data | |
88467055 CL |
787 | * @count: number of bytes to write |
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 | */ | |
d4cc948b | 808 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos) |
1da177e4 | 809 | { |
ce1a8e67 | 810 | ssize_t retval; |
1da177e4 | 811 | struct file *file = iocb->ki_filp; |
1da177e4 | 812 | struct address_space *mapping = file->f_mapping; |
1da177e4 | 813 | |
ce1a8e67 | 814 | dfprintk(VFS, "nfs: direct write(%s/%s, %lu@%Ld)\n", |
0bbacc40 | 815 | file->f_dentry->d_parent->d_name.name, |
ce1a8e67 CL |
816 | file->f_dentry->d_name.name, |
817 | (unsigned long) count, (long long) pos); | |
1da177e4 | 818 | |
ce1a8e67 CL |
819 | retval = generic_write_checks(file, &pos, &count, 0); |
820 | if (retval) | |
1da177e4 | 821 | goto out; |
ce1a8e67 CL |
822 | |
823 | retval = -EINVAL; | |
824 | if ((ssize_t) count < 0) | |
1da177e4 | 825 | goto out; |
1da177e4 LT |
826 | retval = 0; |
827 | if (!count) | |
828 | goto out; | |
ce1a8e67 CL |
829 | |
830 | retval = -EFAULT; | |
47989d74 | 831 | if (!access_ok(VERIFY_READ, buf, count)) |
ce1a8e67 | 832 | goto out; |
1da177e4 | 833 | |
29884df0 TM |
834 | retval = nfs_sync_mapping(mapping); |
835 | if (retval) | |
836 | goto out; | |
1da177e4 | 837 | |
06cf6f2e | 838 | retval = nfs_direct_write(iocb, (unsigned long) buf, count, pos); |
9eafa8cc CL |
839 | |
840 | /* | |
841 | * XXX: nfs_end_data_update() already ensures this file's | |
842 | * cached data is subsequently invalidated. Do we really | |
843 | * need to call invalidate_inode_pages2() again here? | |
844 | * | |
845 | * For aio writes, this invalidation will almost certainly | |
846 | * occur before the writes complete. Kind of racey. | |
847 | */ | |
1da177e4 LT |
848 | if (mapping->nrpages) |
849 | invalidate_inode_pages2(mapping); | |
9eafa8cc | 850 | |
1da177e4 | 851 | if (retval > 0) |
ce1a8e67 | 852 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
853 | |
854 | out: | |
855 | return retval; | |
856 | } | |
857 | ||
88467055 CL |
858 | /** |
859 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
860 | * | |
861 | */ | |
f7b422b1 | 862 | int __init nfs_init_directcache(void) |
1da177e4 LT |
863 | { |
864 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
865 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
866 | 0, (SLAB_RECLAIM_ACCOUNT| |
867 | SLAB_MEM_SPREAD), | |
1da177e4 LT |
868 | NULL, NULL); |
869 | if (nfs_direct_cachep == NULL) | |
870 | return -ENOMEM; | |
871 | ||
872 | return 0; | |
873 | } | |
874 | ||
88467055 | 875 | /** |
f7b422b1 | 876 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
877 | * |
878 | */ | |
f7b422b1 | 879 | void __exit nfs_destroy_directcache(void) |
1da177e4 LT |
880 | { |
881 | if (kmem_cache_destroy(nfs_direct_cachep)) | |
882 | printk(KERN_INFO "nfs_direct_cache: not all structures were freed\n"); | |
883 | } |