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 */ | |
fad61490 TM |
71 | struct list_head list, /* nfs_read/write_data structs */ |
72 | rewrite_list; /* saved nfs_write_data structs */ | |
a8881f5a | 73 | struct nfs_open_context *ctx; /* file open context info */ |
99514f8f | 74 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 75 | struct inode * inode; /* target file of i/o */ |
fad61490 TM |
76 | unsigned long user_addr; /* location of user's buffer */ |
77 | size_t user_count; /* total bytes to move */ | |
78 | loff_t pos; /* starting offset in file */ | |
1da177e4 LT |
79 | struct page ** pages; /* pages in our buffer */ |
80 | unsigned int npages; /* count of pages */ | |
15ce4a0c CL |
81 | |
82 | /* completion state */ | |
b1c5921c | 83 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 84 | spinlock_t lock; /* protect completion state */ |
15ce4a0c | 85 | ssize_t count, /* bytes actually processed */ |
1da177e4 | 86 | error; /* any reported error */ |
d72b7a6b | 87 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
88 | |
89 | /* commit state */ | |
90 | struct nfs_write_data * commit_data; /* special write_data for commits */ | |
91 | int flags; | |
92 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ | |
93 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
94 | struct nfs_writeverf verf; /* unstable write verifier */ | |
1da177e4 LT |
95 | }; |
96 | ||
fad61490 TM |
97 | static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync); |
98 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); | |
1da177e4 | 99 | |
b1c5921c CL |
100 | static inline void get_dreq(struct nfs_direct_req *dreq) |
101 | { | |
102 | atomic_inc(&dreq->io_count); | |
103 | } | |
104 | ||
105 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
106 | { | |
107 | return atomic_dec_and_test(&dreq->io_count); | |
108 | } | |
109 | ||
1da177e4 | 110 | /** |
b8a32e2b CL |
111 | * nfs_direct_IO - NFS address space operation for direct I/O |
112 | * @rw: direction (read or write) | |
113 | * @iocb: target I/O control block | |
114 | * @iov: array of vectors that define I/O buffer | |
115 | * @pos: offset in file to begin the operation | |
116 | * @nr_segs: size of iovec array | |
117 | * | |
118 | * The presence of this routine in the address space ops vector means | |
119 | * the NFS client supports direct I/O. However, we shunt off direct | |
120 | * read and write requests before the VFS gets them, so this method | |
121 | * should never be called. | |
1da177e4 | 122 | */ |
b8a32e2b CL |
123 | ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) |
124 | { | |
b8a32e2b | 125 | dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", |
e99170ff TM |
126 | iocb->ki_filp->f_dentry->d_name.name, |
127 | (long long) pos, nr_segs); | |
b8a32e2b CL |
128 | |
129 | return -EINVAL; | |
130 | } | |
131 | ||
6b45d858 TM |
132 | static void nfs_free_user_pages(struct page **pages, int npages, int do_dirty) |
133 | { | |
134 | int i; | |
135 | for (i = 0; i < npages; i++) { | |
136 | struct page *page = pages[i]; | |
137 | if (do_dirty && !PageCompound(page)) | |
138 | set_page_dirty_lock(page); | |
139 | page_cache_release(page); | |
140 | } | |
141 | kfree(pages); | |
142 | } | |
143 | ||
d4cc948b | 144 | static inline int nfs_get_user_pages(int rw, unsigned long user_addr, size_t size, struct page ***pages) |
1da177e4 LT |
145 | { |
146 | int result = -ENOMEM; | |
147 | unsigned long page_count; | |
148 | size_t array_size; | |
149 | ||
1da177e4 LT |
150 | page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
151 | page_count -= user_addr >> PAGE_SHIFT; | |
152 | ||
153 | array_size = (page_count * sizeof(struct page *)); | |
154 | *pages = kmalloc(array_size, GFP_KERNEL); | |
155 | if (*pages) { | |
156 | down_read(¤t->mm->mmap_sem); | |
157 | result = get_user_pages(current, current->mm, user_addr, | |
158 | page_count, (rw == READ), 0, | |
159 | *pages, NULL); | |
160 | up_read(¤t->mm->mmap_sem); | |
6b45d858 TM |
161 | if (result != page_count) { |
162 | /* | |
163 | * If we got fewer pages than expected from | |
164 | * get_user_pages(), the user buffer runs off the | |
165 | * end of a mapping; return EFAULT. | |
166 | */ | |
167 | if (result >= 0) { | |
168 | nfs_free_user_pages(*pages, result, 0); | |
169 | result = -EFAULT; | |
170 | } else | |
171 | kfree(*pages); | |
143f412e | 172 | *pages = NULL; |
143f412e | 173 | } |
1da177e4 LT |
174 | } |
175 | return result; | |
176 | } | |
177 | ||
93619e59 | 178 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 179 | { |
93619e59 CL |
180 | struct nfs_direct_req *dreq; |
181 | ||
182 | dreq = kmem_cache_alloc(nfs_direct_cachep, SLAB_KERNEL); | |
183 | if (!dreq) | |
184 | return NULL; | |
185 | ||
186 | kref_init(&dreq->kref); | |
d72b7a6b | 187 | init_completion(&dreq->completion); |
93619e59 | 188 | INIT_LIST_HEAD(&dreq->list); |
fad61490 | 189 | INIT_LIST_HEAD(&dreq->rewrite_list); |
93619e59 | 190 | dreq->iocb = NULL; |
a8881f5a | 191 | dreq->ctx = NULL; |
15ce4a0c | 192 | spin_lock_init(&dreq->lock); |
b1c5921c | 193 | atomic_set(&dreq->io_count, 0); |
15ce4a0c CL |
194 | dreq->count = 0; |
195 | dreq->error = 0; | |
fad61490 | 196 | dreq->flags = 0; |
93619e59 CL |
197 | |
198 | return dreq; | |
1da177e4 LT |
199 | } |
200 | ||
1da177e4 LT |
201 | static void nfs_direct_req_release(struct kref *kref) |
202 | { | |
203 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a TM |
204 | |
205 | if (dreq->ctx != NULL) | |
206 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
207 | kmem_cache_free(nfs_direct_cachep, dreq); |
208 | } | |
209 | ||
bc0fb201 CL |
210 | /* |
211 | * Collects and returns the final error value/byte-count. | |
212 | */ | |
213 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
214 | { | |
15ce4a0c | 215 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
216 | |
217 | /* Async requests don't wait here */ | |
218 | if (dreq->iocb) | |
219 | goto out; | |
220 | ||
d72b7a6b | 221 | result = wait_for_completion_interruptible(&dreq->completion); |
bc0fb201 CL |
222 | |
223 | if (!result) | |
15ce4a0c | 224 | result = dreq->error; |
bc0fb201 | 225 | if (!result) |
15ce4a0c | 226 | result = dreq->count; |
bc0fb201 CL |
227 | |
228 | out: | |
229 | kref_put(&dreq->kref, nfs_direct_req_release); | |
230 | return (ssize_t) result; | |
231 | } | |
232 | ||
63ab46ab CL |
233 | /* |
234 | * We must hold a reference to all the pages in this direct read request | |
235 | * until the RPCs complete. This could be long *after* we are woken up in | |
236 | * nfs_direct_wait (for instance, if someone hits ^C on a slow server). | |
1da177e4 | 237 | * |
63ab46ab CL |
238 | * In addition, synchronous I/O uses a stack-allocated iocb. Thus we |
239 | * can't trust the iocb is still valid here if this is a synchronous | |
240 | * request. If the waiter is woken prematurely, the iocb is long gone. | |
241 | */ | |
242 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
243 | { | |
244 | nfs_free_user_pages(dreq->pages, dreq->npages, 1); | |
245 | ||
246 | if (dreq->iocb) { | |
15ce4a0c | 247 | long res = (long) dreq->error; |
63ab46ab | 248 | if (!res) |
15ce4a0c | 249 | res = (long) dreq->count; |
63ab46ab | 250 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
251 | } |
252 | complete_all(&dreq->completion); | |
63ab46ab CL |
253 | |
254 | kref_put(&dreq->kref, nfs_direct_req_release); | |
255 | } | |
256 | ||
d4cc948b | 257 | /* |
1da177e4 LT |
258 | * Note we also set the number of requests we have in the dreq when we are |
259 | * done. This prevents races with I/O completion so we will always wait | |
260 | * until all requests have been dispatched and completed. | |
261 | */ | |
5dd602f2 | 262 | static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize) |
1da177e4 LT |
263 | { |
264 | struct list_head *list; | |
265 | struct nfs_direct_req *dreq; | |
40859d7e | 266 | unsigned int rpages = (rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
1da177e4 | 267 | |
93619e59 | 268 | dreq = nfs_direct_req_alloc(); |
1da177e4 LT |
269 | if (!dreq) |
270 | return NULL; | |
271 | ||
1da177e4 LT |
272 | list = &dreq->list; |
273 | for(;;) { | |
40859d7e | 274 | struct nfs_read_data *data = nfs_readdata_alloc(rpages); |
1da177e4 LT |
275 | |
276 | if (unlikely(!data)) { | |
277 | while (!list_empty(list)) { | |
278 | data = list_entry(list->next, | |
279 | struct nfs_read_data, pages); | |
280 | list_del(&data->pages); | |
281 | nfs_readdata_free(data); | |
282 | } | |
283 | kref_put(&dreq->kref, nfs_direct_req_release); | |
284 | return NULL; | |
285 | } | |
286 | ||
287 | INIT_LIST_HEAD(&data->pages); | |
288 | list_add(&data->pages, list); | |
289 | ||
290 | data->req = (struct nfs_page *) dreq; | |
b1c5921c | 291 | get_dreq(dreq); |
1da177e4 LT |
292 | if (nbytes <= rsize) |
293 | break; | |
294 | nbytes -= rsize; | |
295 | } | |
296 | kref_get(&dreq->kref); | |
1da177e4 LT |
297 | return dreq; |
298 | } | |
299 | ||
ec06c096 | 300 | static void nfs_direct_read_result(struct rpc_task *task, void *calldata) |
1da177e4 | 301 | { |
ec06c096 | 302 | struct nfs_read_data *data = calldata; |
1da177e4 LT |
303 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; |
304 | ||
ec06c096 TM |
305 | if (nfs_readpage_result(task, data) != 0) |
306 | return; | |
15ce4a0c CL |
307 | |
308 | spin_lock(&dreq->lock); | |
309 | ||
ec06c096 | 310 | if (likely(task->tk_status >= 0)) |
15ce4a0c | 311 | dreq->count += data->res.count; |
1da177e4 | 312 | else |
15ce4a0c | 313 | dreq->error = task->tk_status; |
1da177e4 | 314 | |
15ce4a0c | 315 | spin_unlock(&dreq->lock); |
b1c5921c CL |
316 | |
317 | if (put_dreq(dreq)) | |
318 | nfs_direct_complete(dreq); | |
1da177e4 LT |
319 | } |
320 | ||
ec06c096 TM |
321 | static const struct rpc_call_ops nfs_read_direct_ops = { |
322 | .rpc_call_done = nfs_direct_read_result, | |
323 | .rpc_release = nfs_readdata_release, | |
324 | }; | |
325 | ||
d4cc948b | 326 | /* |
1da177e4 LT |
327 | * For each nfs_read_data struct that was allocated on the list, dispatch |
328 | * an NFS READ operation | |
329 | */ | |
fad61490 | 330 | static void nfs_direct_read_schedule(struct nfs_direct_req *dreq) |
1da177e4 | 331 | { |
a8881f5a TM |
332 | struct nfs_open_context *ctx = dreq->ctx; |
333 | struct inode *inode = ctx->dentry->d_inode; | |
1da177e4 LT |
334 | struct list_head *list = &dreq->list; |
335 | struct page **pages = dreq->pages; | |
fad61490 TM |
336 | size_t count = dreq->user_count; |
337 | loff_t pos = dreq->pos; | |
5dd602f2 | 338 | size_t rsize = NFS_SERVER(inode)->rsize; |
1da177e4 | 339 | unsigned int curpage, pgbase; |
1da177e4 LT |
340 | |
341 | curpage = 0; | |
fad61490 | 342 | pgbase = dreq->user_addr & ~PAGE_MASK; |
1da177e4 LT |
343 | do { |
344 | struct nfs_read_data *data; | |
5dd602f2 | 345 | size_t bytes; |
1da177e4 LT |
346 | |
347 | bytes = rsize; | |
348 | if (count < rsize) | |
349 | bytes = count; | |
350 | ||
5db3a7b2 | 351 | BUG_ON(list_empty(list)); |
1da177e4 LT |
352 | data = list_entry(list->next, struct nfs_read_data, pages); |
353 | list_del_init(&data->pages); | |
354 | ||
355 | data->inode = inode; | |
356 | data->cred = ctx->cred; | |
357 | data->args.fh = NFS_FH(inode); | |
358 | data->args.context = ctx; | |
88467055 | 359 | data->args.offset = pos; |
1da177e4 LT |
360 | data->args.pgbase = pgbase; |
361 | data->args.pages = &pages[curpage]; | |
362 | data->args.count = bytes; | |
363 | data->res.fattr = &data->fattr; | |
364 | data->res.eof = 0; | |
365 | data->res.count = bytes; | |
366 | ||
ec06c096 TM |
367 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, |
368 | &nfs_read_direct_ops, data); | |
1da177e4 LT |
369 | NFS_PROTO(inode)->read_setup(data); |
370 | ||
371 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
372 | |
373 | lock_kernel(); | |
374 | rpc_execute(&data->task); | |
375 | unlock_kernel(); | |
376 | ||
606bbba0 | 377 | dfprintk(VFS, "NFS: %5u initiated direct read call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
1da177e4 LT |
378 | data->task.tk_pid, |
379 | inode->i_sb->s_id, | |
380 | (long long)NFS_FILEID(inode), | |
381 | bytes, | |
382 | (unsigned long long)data->args.offset); | |
383 | ||
88467055 | 384 | pos += bytes; |
1da177e4 LT |
385 | pgbase += bytes; |
386 | curpage += pgbase >> PAGE_SHIFT; | |
387 | pgbase &= ~PAGE_MASK; | |
388 | ||
389 | count -= bytes; | |
390 | } while (count != 0); | |
5db3a7b2 | 391 | BUG_ON(!list_empty(list)); |
1da177e4 LT |
392 | } |
393 | ||
88467055 | 394 | static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, unsigned int nr_pages) |
1da177e4 LT |
395 | { |
396 | ssize_t result; | |
397 | sigset_t oldset; | |
99514f8f | 398 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
399 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
400 | struct nfs_direct_req *dreq; | |
401 | ||
402 | dreq = nfs_direct_read_alloc(count, NFS_SERVER(inode)->rsize); | |
403 | if (!dreq) | |
404 | return -ENOMEM; | |
405 | ||
fad61490 TM |
406 | dreq->user_addr = user_addr; |
407 | dreq->user_count = count; | |
408 | dreq->pos = pos; | |
1da177e4 LT |
409 | dreq->pages = pages; |
410 | dreq->npages = nr_pages; | |
91d5b470 | 411 | dreq->inode = inode; |
a8881f5a | 412 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
487b8372 CL |
413 | if (!is_sync_kiocb(iocb)) |
414 | dreq->iocb = iocb; | |
1da177e4 | 415 | |
91d5b470 | 416 | nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); |
1da177e4 | 417 | rpc_clnt_sigmask(clnt, &oldset); |
fad61490 | 418 | nfs_direct_read_schedule(dreq); |
bc0fb201 | 419 | result = nfs_direct_wait(dreq); |
1da177e4 LT |
420 | rpc_clnt_sigunmask(clnt, &oldset); |
421 | ||
422 | return result; | |
423 | } | |
424 | ||
fad61490 | 425 | static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) |
1da177e4 | 426 | { |
fad61490 TM |
427 | list_splice_init(&dreq->rewrite_list, &dreq->list); |
428 | while (!list_empty(&dreq->list)) { | |
429 | struct nfs_write_data *data = list_entry(dreq->list.next, struct nfs_write_data, pages); | |
430 | list_del(&data->pages); | |
431 | nfs_writedata_release(data); | |
432 | } | |
433 | } | |
1da177e4 | 434 | |
fad61490 TM |
435 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
436 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
437 | { | |
438 | struct list_head *pos; | |
1da177e4 | 439 | |
fad61490 TM |
440 | list_splice_init(&dreq->rewrite_list, &dreq->list); |
441 | list_for_each(pos, &dreq->list) | |
b1c5921c | 442 | get_dreq(dreq); |
fad61490 TM |
443 | dreq->count = 0; |
444 | ||
445 | nfs_direct_write_schedule(dreq, FLUSH_STABLE); | |
446 | } | |
447 | ||
448 | static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) | |
449 | { | |
450 | struct nfs_write_data *data = calldata; | |
451 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
452 | ||
453 | /* Call the NFS version-specific code */ | |
454 | if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) | |
455 | return; | |
456 | if (unlikely(task->tk_status < 0)) { | |
457 | dreq->error = task->tk_status; | |
458 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
459 | } | |
460 | if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { | |
461 | dprintk("NFS: %5u commit verify failed\n", task->tk_pid); | |
462 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
1da177e4 LT |
463 | } |
464 | ||
fad61490 TM |
465 | dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); |
466 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
467 | } |
468 | ||
fad61490 TM |
469 | static const struct rpc_call_ops nfs_commit_direct_ops = { |
470 | .rpc_call_done = nfs_direct_commit_result, | |
471 | .rpc_release = nfs_commit_release, | |
472 | }; | |
473 | ||
474 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 475 | { |
fad61490 | 476 | struct nfs_write_data *data = dreq->commit_data; |
1da177e4 | 477 | |
fad61490 | 478 | data->inode = dreq->inode; |
a8881f5a | 479 | data->cred = dreq->ctx->cred; |
1da177e4 | 480 | |
fad61490 TM |
481 | data->args.fh = NFS_FH(data->inode); |
482 | data->args.offset = dreq->pos; | |
483 | data->args.count = dreq->user_count; | |
484 | data->res.count = 0; | |
485 | data->res.fattr = &data->fattr; | |
486 | data->res.verf = &data->verf; | |
1da177e4 | 487 | |
fad61490 TM |
488 | rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC, |
489 | &nfs_commit_direct_ops, data); | |
490 | NFS_PROTO(data->inode)->commit_setup(data, 0); | |
1da177e4 | 491 | |
fad61490 TM |
492 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
493 | data->task.tk_cookie = (unsigned long)data->inode; | |
494 | /* Note: task.tk_ops->rpc_release will free dreq->commit_data */ | |
495 | dreq->commit_data = NULL; | |
1da177e4 | 496 | |
e99170ff | 497 | dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
1da177e4 | 498 | |
fad61490 TM |
499 | lock_kernel(); |
500 | rpc_execute(&data->task); | |
501 | unlock_kernel(); | |
502 | } | |
1da177e4 | 503 | |
fad61490 TM |
504 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
505 | { | |
506 | int flags = dreq->flags; | |
1da177e4 | 507 | |
fad61490 TM |
508 | dreq->flags = 0; |
509 | switch (flags) { | |
510 | case NFS_ODIRECT_DO_COMMIT: | |
511 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 512 | break; |
fad61490 TM |
513 | case NFS_ODIRECT_RESCHED_WRITES: |
514 | nfs_direct_write_reschedule(dreq); | |
515 | break; | |
516 | default: | |
517 | nfs_end_data_update(inode); | |
518 | if (dreq->commit_data != NULL) | |
519 | nfs_commit_free(dreq->commit_data); | |
520 | nfs_direct_free_writedata(dreq); | |
521 | nfs_direct_complete(dreq); | |
522 | } | |
523 | } | |
1da177e4 | 524 | |
fad61490 TM |
525 | static void nfs_alloc_commit_data(struct nfs_direct_req *dreq) |
526 | { | |
527 | dreq->commit_data = nfs_commit_alloc(0); | |
528 | if (dreq->commit_data != NULL) | |
529 | dreq->commit_data->req = (struct nfs_page *) dreq; | |
530 | } | |
531 | #else | |
532 | static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq) | |
533 | { | |
534 | dreq->commit_data = NULL; | |
535 | } | |
1da177e4 | 536 | |
fad61490 TM |
537 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
538 | { | |
539 | nfs_end_data_update(inode); | |
540 | nfs_direct_free_writedata(dreq); | |
541 | nfs_direct_complete(dreq); | |
542 | } | |
543 | #endif | |
1da177e4 | 544 | |
462d5b32 | 545 | static struct nfs_direct_req *nfs_direct_write_alloc(size_t nbytes, size_t wsize) |
1da177e4 | 546 | { |
462d5b32 CL |
547 | struct list_head *list; |
548 | struct nfs_direct_req *dreq; | |
462d5b32 | 549 | unsigned int wpages = (wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
1da177e4 | 550 | |
462d5b32 CL |
551 | dreq = nfs_direct_req_alloc(); |
552 | if (!dreq) | |
553 | return NULL; | |
554 | ||
555 | list = &dreq->list; | |
556 | for(;;) { | |
557 | struct nfs_write_data *data = nfs_writedata_alloc(wpages); | |
1da177e4 | 558 | |
462d5b32 CL |
559 | if (unlikely(!data)) { |
560 | while (!list_empty(list)) { | |
561 | data = list_entry(list->next, | |
562 | struct nfs_write_data, pages); | |
563 | list_del(&data->pages); | |
564 | nfs_writedata_free(data); | |
565 | } | |
566 | kref_put(&dreq->kref, nfs_direct_req_release); | |
567 | return NULL; | |
568 | } | |
569 | ||
570 | INIT_LIST_HEAD(&data->pages); | |
571 | list_add(&data->pages, list); | |
572 | ||
573 | data->req = (struct nfs_page *) dreq; | |
b1c5921c | 574 | get_dreq(dreq); |
462d5b32 CL |
575 | if (nbytes <= wsize) |
576 | break; | |
577 | nbytes -= wsize; | |
1da177e4 | 578 | } |
1da177e4 | 579 | |
fad61490 | 580 | nfs_alloc_commit_data(dreq); |
1da177e4 | 581 | |
462d5b32 | 582 | kref_get(&dreq->kref); |
462d5b32 | 583 | return dreq; |
1da177e4 LT |
584 | } |
585 | ||
462d5b32 | 586 | static void nfs_direct_write_result(struct rpc_task *task, void *calldata) |
1da177e4 | 587 | { |
462d5b32 CL |
588 | struct nfs_write_data *data = calldata; |
589 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
590 | int status = task->tk_status; | |
591 | ||
592 | if (nfs_writeback_done(task, data) != 0) | |
593 | return; | |
462d5b32 | 594 | |
15ce4a0c | 595 | spin_lock(&dreq->lock); |
1da177e4 | 596 | |
462d5b32 | 597 | if (likely(status >= 0)) |
15ce4a0c | 598 | dreq->count += data->res.count; |
462d5b32 | 599 | else |
fad61490 | 600 | dreq->error = task->tk_status; |
1da177e4 | 601 | |
fad61490 TM |
602 | if (data->res.verf->committed != NFS_FILE_SYNC) { |
603 | switch (dreq->flags) { | |
604 | case 0: | |
605 | memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf)); | |
606 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
1da177e4 | 607 | break; |
fad61490 TM |
608 | case NFS_ODIRECT_DO_COMMIT: |
609 | if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) { | |
610 | dprintk("NFS: %5u write verify failed\n", task->tk_pid); | |
611 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
612 | } | |
1da177e4 | 613 | } |
1da177e4 | 614 | } |
fad61490 TM |
615 | /* In case we have to resend */ |
616 | data->args.stable = NFS_FILE_SYNC; | |
617 | ||
618 | spin_unlock(&dreq->lock); | |
1da177e4 LT |
619 | } |
620 | ||
fad61490 TM |
621 | /* |
622 | * NB: Return the value of the first error return code. Subsequent | |
623 | * errors after the first one are ignored. | |
1da177e4 | 624 | */ |
fad61490 | 625 | static void nfs_direct_write_release(void *calldata) |
1da177e4 | 626 | { |
fad61490 TM |
627 | struct nfs_write_data *data = calldata; |
628 | struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; | |
1da177e4 | 629 | |
b1c5921c CL |
630 | if (put_dreq(dreq)) |
631 | nfs_direct_write_complete(dreq, data->inode); | |
462d5b32 CL |
632 | } |
633 | ||
634 | static const struct rpc_call_ops nfs_write_direct_ops = { | |
635 | .rpc_call_done = nfs_direct_write_result, | |
fad61490 | 636 | .rpc_release = nfs_direct_write_release, |
462d5b32 CL |
637 | }; |
638 | ||
639 | /* | |
640 | * For each nfs_write_data struct that was allocated on the list, dispatch | |
641 | * an NFS WRITE operation | |
462d5b32 | 642 | */ |
fad61490 | 643 | static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync) |
462d5b32 | 644 | { |
a8881f5a TM |
645 | struct nfs_open_context *ctx = dreq->ctx; |
646 | struct inode *inode = ctx->dentry->d_inode; | |
462d5b32 CL |
647 | struct list_head *list = &dreq->list; |
648 | struct page **pages = dreq->pages; | |
fad61490 TM |
649 | size_t count = dreq->user_count; |
650 | loff_t pos = dreq->pos; | |
462d5b32 CL |
651 | size_t wsize = NFS_SERVER(inode)->wsize; |
652 | unsigned int curpage, pgbase; | |
1da177e4 | 653 | |
1da177e4 | 654 | curpage = 0; |
fad61490 | 655 | pgbase = dreq->user_addr & ~PAGE_MASK; |
1da177e4 | 656 | do { |
462d5b32 CL |
657 | struct nfs_write_data *data; |
658 | size_t bytes; | |
659 | ||
660 | bytes = wsize; | |
661 | if (count < wsize) | |
662 | bytes = count; | |
663 | ||
5db3a7b2 | 664 | BUG_ON(list_empty(list)); |
462d5b32 | 665 | data = list_entry(list->next, struct nfs_write_data, pages); |
fad61490 | 666 | list_move_tail(&data->pages, &dreq->rewrite_list); |
462d5b32 CL |
667 | |
668 | data->inode = inode; | |
669 | data->cred = ctx->cred; | |
670 | data->args.fh = NFS_FH(inode); | |
671 | data->args.context = ctx; | |
88467055 | 672 | data->args.offset = pos; |
462d5b32 CL |
673 | data->args.pgbase = pgbase; |
674 | data->args.pages = &pages[curpage]; | |
675 | data->args.count = bytes; | |
676 | data->res.fattr = &data->fattr; | |
677 | data->res.count = bytes; | |
47989d74 | 678 | data->res.verf = &data->verf; |
462d5b32 CL |
679 | |
680 | rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, | |
681 | &nfs_write_direct_ops, data); | |
fad61490 | 682 | NFS_PROTO(inode)->write_setup(data, sync); |
1da177e4 | 683 | |
462d5b32 CL |
684 | data->task.tk_priority = RPC_PRIORITY_NORMAL; |
685 | data->task.tk_cookie = (unsigned long) inode; | |
1da177e4 LT |
686 | |
687 | lock_kernel(); | |
462d5b32 | 688 | rpc_execute(&data->task); |
1da177e4 LT |
689 | unlock_kernel(); |
690 | ||
606bbba0 | 691 | dfprintk(VFS, "NFS: %5u initiated direct write call (req %s/%Ld, %zu bytes @ offset %Lu)\n", |
462d5b32 CL |
692 | data->task.tk_pid, |
693 | inode->i_sb->s_id, | |
694 | (long long)NFS_FILEID(inode), | |
695 | bytes, | |
696 | (unsigned long long)data->args.offset); | |
1da177e4 | 697 | |
88467055 | 698 | pos += bytes; |
462d5b32 CL |
699 | pgbase += bytes; |
700 | curpage += pgbase >> PAGE_SHIFT; | |
701 | pgbase &= ~PAGE_MASK; | |
1da177e4 | 702 | |
462d5b32 CL |
703 | count -= bytes; |
704 | } while (count != 0); | |
5db3a7b2 | 705 | BUG_ON(!list_empty(list)); |
462d5b32 | 706 | } |
1da177e4 | 707 | |
88467055 | 708 | static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, int nr_pages) |
462d5b32 CL |
709 | { |
710 | ssize_t result; | |
711 | sigset_t oldset; | |
c89f2ee5 | 712 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 CL |
713 | struct rpc_clnt *clnt = NFS_CLIENT(inode); |
714 | struct nfs_direct_req *dreq; | |
fad61490 TM |
715 | size_t wsize = NFS_SERVER(inode)->wsize; |
716 | int sync = 0; | |
1da177e4 | 717 | |
fad61490 | 718 | dreq = nfs_direct_write_alloc(count, wsize); |
462d5b32 CL |
719 | if (!dreq) |
720 | return -ENOMEM; | |
fad61490 TM |
721 | if (dreq->commit_data == NULL || count < wsize) |
722 | sync = FLUSH_STABLE; | |
1da177e4 | 723 | |
fad61490 TM |
724 | dreq->user_addr = user_addr; |
725 | dreq->user_count = count; | |
726 | dreq->pos = pos; | |
462d5b32 CL |
727 | dreq->pages = pages; |
728 | dreq->npages = nr_pages; | |
c89f2ee5 | 729 | dreq->inode = inode; |
a8881f5a | 730 | dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data); |
c89f2ee5 CL |
731 | if (!is_sync_kiocb(iocb)) |
732 | dreq->iocb = iocb; | |
1da177e4 | 733 | |
47989d74 CL |
734 | nfs_add_stats(inode, NFSIOS_DIRECTWRITTENBYTES, count); |
735 | ||
462d5b32 | 736 | nfs_begin_data_update(inode); |
1da177e4 | 737 | |
462d5b32 | 738 | rpc_clnt_sigmask(clnt, &oldset); |
fad61490 | 739 | nfs_direct_write_schedule(dreq, sync); |
c89f2ee5 | 740 | result = nfs_direct_wait(dreq); |
462d5b32 | 741 | rpc_clnt_sigunmask(clnt, &oldset); |
1da177e4 | 742 | |
1da177e4 LT |
743 | return result; |
744 | } | |
745 | ||
746 | /** | |
747 | * nfs_file_direct_read - file direct read operation for NFS files | |
748 | * @iocb: target I/O control block | |
749 | * @buf: user's buffer into which to read data | |
88467055 CL |
750 | * @count: number of bytes to read |
751 | * @pos: byte offset in file where reading starts | |
1da177e4 LT |
752 | * |
753 | * We use this function for direct reads instead of calling | |
754 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
755 | * the request starts before the end of the file. For that check | |
756 | * to work, we must generate a GETATTR before each direct read, and | |
757 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 758 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
759 | * to do all reads the application wants, and the server will take |
760 | * care of managing the end of file boundary. | |
88467055 | 761 | * |
1da177e4 LT |
762 | * This function also eliminates unnecessarily updating the file's |
763 | * atime locally, as the NFS server sets the file's atime, and this | |
764 | * client must read the updated atime from the server back into its | |
765 | * cache. | |
766 | */ | |
d4cc948b | 767 | ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos) |
1da177e4 LT |
768 | { |
769 | ssize_t retval = -EINVAL; | |
0cdd80d0 CL |
770 | int page_count; |
771 | struct page **pages; | |
1da177e4 | 772 | struct file *file = iocb->ki_filp; |
1da177e4 | 773 | struct address_space *mapping = file->f_mapping; |
1da177e4 | 774 | |
ce1a8e67 | 775 | dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n", |
0bbacc40 CL |
776 | file->f_dentry->d_parent->d_name.name, |
777 | file->f_dentry->d_name.name, | |
ce1a8e67 | 778 | (unsigned long) count, (long long) pos); |
1da177e4 | 779 | |
1da177e4 LT |
780 | if (count < 0) |
781 | goto out; | |
782 | retval = -EFAULT; | |
0cdd80d0 | 783 | if (!access_ok(VERIFY_WRITE, buf, count)) |
1da177e4 LT |
784 | goto out; |
785 | retval = 0; | |
786 | if (!count) | |
787 | goto out; | |
788 | ||
29884df0 TM |
789 | retval = nfs_sync_mapping(mapping); |
790 | if (retval) | |
791 | goto out; | |
1da177e4 | 792 | |
6b45d858 | 793 | retval = nfs_get_user_pages(READ, (unsigned long) buf, |
0cdd80d0 | 794 | count, &pages); |
6b45d858 | 795 | if (retval < 0) |
0cdd80d0 | 796 | goto out; |
6b45d858 | 797 | page_count = retval; |
0cdd80d0 | 798 | |
99514f8f | 799 | retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos, |
0cdd80d0 | 800 | pages, page_count); |
1da177e4 | 801 | if (retval > 0) |
0cdd80d0 | 802 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
803 | |
804 | out: | |
805 | return retval; | |
806 | } | |
807 | ||
808 | /** | |
809 | * nfs_file_direct_write - file direct write operation for NFS files | |
810 | * @iocb: target I/O control block | |
811 | * @buf: user's buffer from which to write data | |
88467055 CL |
812 | * @count: number of bytes to write |
813 | * @pos: byte offset in file where writing starts | |
1da177e4 LT |
814 | * |
815 | * We use this function for direct writes instead of calling | |
816 | * generic_file_aio_write() in order to avoid taking the inode | |
817 | * semaphore and updating the i_size. The NFS server will set | |
818 | * the new i_size and this client must read the updated size | |
819 | * back into its cache. We let the server do generic write | |
820 | * parameter checking and report problems. | |
821 | * | |
822 | * We also avoid an unnecessary invocation of generic_osync_inode(), | |
823 | * as it is fairly meaningless to sync the metadata of an NFS file. | |
824 | * | |
825 | * We eliminate local atime updates, see direct read above. | |
826 | * | |
827 | * We avoid unnecessary page cache invalidations for normal cached | |
828 | * readers of this file. | |
829 | * | |
830 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
831 | * is no atomic O_APPEND write facility in the NFS protocol. | |
832 | */ | |
d4cc948b | 833 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos) |
1da177e4 | 834 | { |
ce1a8e67 | 835 | ssize_t retval; |
47989d74 CL |
836 | int page_count; |
837 | struct page **pages; | |
1da177e4 | 838 | struct file *file = iocb->ki_filp; |
1da177e4 | 839 | struct address_space *mapping = file->f_mapping; |
1da177e4 | 840 | |
ce1a8e67 | 841 | dfprintk(VFS, "nfs: direct write(%s/%s, %lu@%Ld)\n", |
0bbacc40 | 842 | file->f_dentry->d_parent->d_name.name, |
ce1a8e67 CL |
843 | file->f_dentry->d_name.name, |
844 | (unsigned long) count, (long long) pos); | |
1da177e4 | 845 | |
ce1a8e67 CL |
846 | retval = generic_write_checks(file, &pos, &count, 0); |
847 | if (retval) | |
1da177e4 | 848 | goto out; |
ce1a8e67 CL |
849 | |
850 | retval = -EINVAL; | |
851 | if ((ssize_t) count < 0) | |
1da177e4 | 852 | goto out; |
1da177e4 LT |
853 | retval = 0; |
854 | if (!count) | |
855 | goto out; | |
ce1a8e67 CL |
856 | |
857 | retval = -EFAULT; | |
47989d74 | 858 | if (!access_ok(VERIFY_READ, buf, count)) |
ce1a8e67 | 859 | goto out; |
1da177e4 | 860 | |
29884df0 TM |
861 | retval = nfs_sync_mapping(mapping); |
862 | if (retval) | |
863 | goto out; | |
1da177e4 | 864 | |
6b45d858 | 865 | retval = nfs_get_user_pages(WRITE, (unsigned long) buf, |
47989d74 | 866 | count, &pages); |
6b45d858 | 867 | if (retval < 0) |
47989d74 | 868 | goto out; |
6b45d858 | 869 | page_count = retval; |
47989d74 | 870 | |
c89f2ee5 | 871 | retval = nfs_direct_write(iocb, (unsigned long) buf, count, |
47989d74 | 872 | pos, pages, page_count); |
9eafa8cc CL |
873 | |
874 | /* | |
875 | * XXX: nfs_end_data_update() already ensures this file's | |
876 | * cached data is subsequently invalidated. Do we really | |
877 | * need to call invalidate_inode_pages2() again here? | |
878 | * | |
879 | * For aio writes, this invalidation will almost certainly | |
880 | * occur before the writes complete. Kind of racey. | |
881 | */ | |
1da177e4 LT |
882 | if (mapping->nrpages) |
883 | invalidate_inode_pages2(mapping); | |
9eafa8cc | 884 | |
1da177e4 | 885 | if (retval > 0) |
ce1a8e67 | 886 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
887 | |
888 | out: | |
889 | return retval; | |
890 | } | |
891 | ||
88467055 CL |
892 | /** |
893 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
894 | * | |
895 | */ | |
f7b422b1 | 896 | int __init nfs_init_directcache(void) |
1da177e4 LT |
897 | { |
898 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
899 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
900 | 0, (SLAB_RECLAIM_ACCOUNT| |
901 | SLAB_MEM_SPREAD), | |
1da177e4 LT |
902 | NULL, NULL); |
903 | if (nfs_direct_cachep == NULL) | |
904 | return -ENOMEM; | |
905 | ||
906 | return 0; | |
907 | } | |
908 | ||
88467055 | 909 | /** |
f7b422b1 | 910 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
911 | * |
912 | */ | |
f7b422b1 | 913 | void __exit nfs_destroy_directcache(void) |
1da177e4 LT |
914 | { |
915 | if (kmem_cache_destroy(nfs_direct_cachep)) | |
916 | printk(KERN_INFO "nfs_direct_cache: not all structures were freed\n"); | |
917 | } |