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> | |
5a0e3ad6 | 47 | #include <linux/slab.h> |
7ec10f26 | 48 | #include <linux/task_io_accounting_ops.h> |
1da177e4 LT |
49 | |
50 | #include <linux/nfs_fs.h> | |
51 | #include <linux/nfs_page.h> | |
52 | #include <linux/sunrpc/clnt.h> | |
53 | ||
1da177e4 | 54 | #include <asm/uaccess.h> |
60063497 | 55 | #include <linux/atomic.h> |
1da177e4 | 56 | |
8d5658c9 | 57 | #include "internal.h" |
91d5b470 | 58 | #include "iostat.h" |
1763da12 | 59 | #include "pnfs.h" |
91d5b470 | 60 | |
1da177e4 | 61 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 | 62 | |
e18b890b | 63 | static struct kmem_cache *nfs_direct_cachep; |
1da177e4 LT |
64 | |
65 | /* | |
66 | * This represents a set of asynchronous requests that we're waiting on | |
67 | */ | |
68 | struct nfs_direct_req { | |
69 | struct kref kref; /* release manager */ | |
15ce4a0c CL |
70 | |
71 | /* I/O parameters */ | |
a8881f5a | 72 | struct nfs_open_context *ctx; /* file open context info */ |
f11ac8db | 73 | struct nfs_lock_context *l_ctx; /* Lock context info */ |
99514f8f | 74 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 75 | struct inode * inode; /* target file of i/o */ |
15ce4a0c CL |
76 | |
77 | /* completion state */ | |
607f31e8 | 78 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 79 | spinlock_t lock; /* protect completion state */ |
15ce4a0c | 80 | ssize_t count, /* bytes actually processed */ |
1da177e4 | 81 | error; /* any reported error */ |
d72b7a6b | 82 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
83 | |
84 | /* commit state */ | |
1763da12 FI |
85 | struct nfs_mds_commit_info mds_cinfo; /* Storage for cinfo */ |
86 | struct pnfs_ds_commit_info ds_cinfo; /* Storage for cinfo */ | |
87 | struct work_struct work; | |
fad61490 TM |
88 | int flags; |
89 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ | |
90 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
91 | struct nfs_writeverf verf; /* unstable write verifier */ | |
1da177e4 LT |
92 | }; |
93 | ||
1763da12 FI |
94 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops; |
95 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops; | |
fad61490 | 96 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); |
1763da12 | 97 | static void nfs_direct_write_schedule_work(struct work_struct *work); |
607f31e8 TM |
98 | |
99 | static inline void get_dreq(struct nfs_direct_req *dreq) | |
100 | { | |
101 | atomic_inc(&dreq->io_count); | |
102 | } | |
103 | ||
104 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
105 | { | |
106 | return atomic_dec_and_test(&dreq->io_count); | |
107 | } | |
108 | ||
1da177e4 | 109 | /** |
b8a32e2b CL |
110 | * nfs_direct_IO - NFS address space operation for direct I/O |
111 | * @rw: direction (read or write) | |
112 | * @iocb: target I/O control block | |
113 | * @iov: array of vectors that define I/O buffer | |
114 | * @pos: offset in file to begin the operation | |
115 | * @nr_segs: size of iovec array | |
116 | * | |
117 | * The presence of this routine in the address space ops vector means | |
118 | * the NFS client supports direct I/O. However, we shunt off direct | |
119 | * read and write requests before the VFS gets them, so this method | |
120 | * should never be called. | |
1da177e4 | 121 | */ |
b8a32e2b CL |
122 | ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) |
123 | { | |
b8a32e2b | 124 | dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", |
01cce933 | 125 | iocb->ki_filp->f_path.dentry->d_name.name, |
e99170ff | 126 | (long long) pos, nr_segs); |
b8a32e2b CL |
127 | |
128 | return -EINVAL; | |
129 | } | |
130 | ||
749e146e | 131 | static void nfs_direct_release_pages(struct page **pages, unsigned int npages) |
9c93ab7d | 132 | { |
749e146e | 133 | unsigned int i; |
607f31e8 TM |
134 | for (i = 0; i < npages; i++) |
135 | page_cache_release(pages[i]); | |
6b45d858 TM |
136 | } |
137 | ||
1763da12 FI |
138 | void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo, |
139 | struct nfs_direct_req *dreq) | |
140 | { | |
141 | cinfo->lock = &dreq->lock; | |
142 | cinfo->mds = &dreq->mds_cinfo; | |
143 | cinfo->ds = &dreq->ds_cinfo; | |
144 | cinfo->dreq = dreq; | |
145 | cinfo->completion_ops = &nfs_direct_commit_completion_ops; | |
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 | ||
292f3eee | 152 | dreq = kmem_cache_zalloc(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); |
1763da12 FI |
159 | INIT_LIST_HEAD(&dreq->mds_cinfo.list); |
160 | INIT_WORK(&dreq->work, nfs_direct_write_schedule_work); | |
15ce4a0c | 161 | spin_lock_init(&dreq->lock); |
93619e59 CL |
162 | |
163 | return dreq; | |
1da177e4 LT |
164 | } |
165 | ||
b4946ffb | 166 | static void nfs_direct_req_free(struct kref *kref) |
1da177e4 LT |
167 | { |
168 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a | 169 | |
f11ac8db TM |
170 | if (dreq->l_ctx != NULL) |
171 | nfs_put_lock_context(dreq->l_ctx); | |
a8881f5a TM |
172 | if (dreq->ctx != NULL) |
173 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
174 | kmem_cache_free(nfs_direct_cachep, dreq); |
175 | } | |
176 | ||
b4946ffb TM |
177 | static void nfs_direct_req_release(struct nfs_direct_req *dreq) |
178 | { | |
179 | kref_put(&dreq->kref, nfs_direct_req_free); | |
180 | } | |
181 | ||
bc0fb201 CL |
182 | /* |
183 | * Collects and returns the final error value/byte-count. | |
184 | */ | |
185 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
186 | { | |
15ce4a0c | 187 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
188 | |
189 | /* Async requests don't wait here */ | |
190 | if (dreq->iocb) | |
191 | goto out; | |
192 | ||
150030b7 | 193 | result = wait_for_completion_killable(&dreq->completion); |
bc0fb201 CL |
194 | |
195 | if (!result) | |
15ce4a0c | 196 | result = dreq->error; |
bc0fb201 | 197 | if (!result) |
15ce4a0c | 198 | result = dreq->count; |
bc0fb201 CL |
199 | |
200 | out: | |
bc0fb201 CL |
201 | return (ssize_t) result; |
202 | } | |
203 | ||
63ab46ab | 204 | /* |
607f31e8 TM |
205 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
206 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
207 | */ |
208 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
209 | { | |
63ab46ab | 210 | if (dreq->iocb) { |
15ce4a0c | 211 | long res = (long) dreq->error; |
63ab46ab | 212 | if (!res) |
15ce4a0c | 213 | res = (long) dreq->count; |
63ab46ab | 214 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
215 | } |
216 | complete_all(&dreq->completion); | |
63ab46ab | 217 | |
b4946ffb | 218 | nfs_direct_req_release(dreq); |
63ab46ab CL |
219 | } |
220 | ||
1385b811 | 221 | static void nfs_direct_readpage_release(struct nfs_page *req) |
1da177e4 | 222 | { |
584aa810 FI |
223 | dprintk("NFS: direct read done (%s/%lld %d@%lld)\n", |
224 | req->wb_context->dentry->d_inode->i_sb->s_id, | |
225 | (long long)NFS_FILEID(req->wb_context->dentry->d_inode), | |
226 | req->wb_bytes, | |
227 | (long long)req_offset(req)); | |
228 | nfs_release_request(req); | |
fdd1e74c TM |
229 | } |
230 | ||
584aa810 | 231 | static void nfs_direct_read_completion(struct nfs_pgio_header *hdr) |
fdd1e74c | 232 | { |
584aa810 FI |
233 | unsigned long bytes = 0; |
234 | struct nfs_direct_req *dreq = hdr->dreq; | |
fdd1e74c | 235 | |
584aa810 FI |
236 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) |
237 | goto out_put; | |
15ce4a0c CL |
238 | |
239 | spin_lock(&dreq->lock); | |
584aa810 FI |
240 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0)) |
241 | dreq->error = hdr->error; | |
242 | else | |
243 | dreq->count += hdr->good_bytes; | |
244 | spin_unlock(&dreq->lock); | |
245 | ||
4bd8b010 TM |
246 | while (!list_empty(&hdr->pages)) { |
247 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
248 | struct page *page = req->wb_page; | |
249 | ||
250 | if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) { | |
251 | if (bytes > hdr->good_bytes) | |
252 | zero_user(page, 0, PAGE_SIZE); | |
253 | else if (hdr->good_bytes - bytes < PAGE_SIZE) | |
254 | zero_user_segment(page, | |
255 | hdr->good_bytes & ~PAGE_MASK, | |
256 | PAGE_SIZE); | |
584aa810 | 257 | } |
4bd8b010 TM |
258 | if (!PageCompound(page)) { |
259 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
260 | if (bytes < hdr->good_bytes) | |
261 | set_page_dirty(page); | |
262 | } else | |
263 | set_page_dirty(page); | |
584aa810 | 264 | } |
4bd8b010 TM |
265 | bytes += req->wb_bytes; |
266 | nfs_list_remove_request(req); | |
267 | nfs_direct_readpage_release(req); | |
d4a8f367 | 268 | } |
584aa810 | 269 | out_put: |
607f31e8 TM |
270 | if (put_dreq(dreq)) |
271 | nfs_direct_complete(dreq); | |
584aa810 | 272 | hdr->release(hdr); |
1da177e4 LT |
273 | } |
274 | ||
3e9e0ca3 | 275 | static void nfs_read_sync_pgio_error(struct list_head *head) |
cd841605 | 276 | { |
584aa810 | 277 | struct nfs_page *req; |
cd841605 | 278 | |
584aa810 FI |
279 | while (!list_empty(head)) { |
280 | req = nfs_list_entry(head->next); | |
281 | nfs_list_remove_request(req); | |
282 | nfs_release_request(req); | |
283 | } | |
cd841605 FI |
284 | } |
285 | ||
584aa810 FI |
286 | static void nfs_direct_pgio_init(struct nfs_pgio_header *hdr) |
287 | { | |
288 | get_dreq(hdr->dreq); | |
289 | } | |
290 | ||
291 | static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = { | |
3e9e0ca3 | 292 | .error_cleanup = nfs_read_sync_pgio_error, |
584aa810 FI |
293 | .init_hdr = nfs_direct_pgio_init, |
294 | .completion = nfs_direct_read_completion, | |
295 | }; | |
296 | ||
d4cc948b | 297 | /* |
607f31e8 TM |
298 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
299 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
300 | * bail and stop sending more reads. Read length accounting is | |
301 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
302 | * no requests have been sent, just return an error. | |
1da177e4 | 303 | */ |
584aa810 | 304 | static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc, |
02fe4946 CL |
305 | const struct iovec *iov, |
306 | loff_t pos) | |
1da177e4 | 307 | { |
584aa810 | 308 | struct nfs_direct_req *dreq = desc->pg_dreq; |
a8881f5a | 309 | struct nfs_open_context *ctx = dreq->ctx; |
3d4ff43d | 310 | struct inode *inode = ctx->dentry->d_inode; |
02fe4946 CL |
311 | unsigned long user_addr = (unsigned long)iov->iov_base; |
312 | size_t count = iov->iov_len; | |
5dd602f2 | 313 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
314 | unsigned int pgbase; |
315 | int result; | |
316 | ssize_t started = 0; | |
584aa810 FI |
317 | struct page **pagevec = NULL; |
318 | unsigned int npages; | |
607f31e8 | 319 | |
1da177e4 | 320 | do { |
5dd602f2 | 321 | size_t bytes; |
584aa810 | 322 | int i; |
1da177e4 | 323 | |
e9f7bee1 | 324 | pgbase = user_addr & ~PAGE_MASK; |
bf5fc402 | 325 | bytes = min(max_t(size_t, rsize, PAGE_SIZE), count); |
e9f7bee1 | 326 | |
607f31e8 | 327 | result = -ENOMEM; |
584aa810 FI |
328 | npages = nfs_page_array_len(pgbase, bytes); |
329 | if (!pagevec) | |
330 | pagevec = kmalloc(npages * sizeof(struct page *), | |
331 | GFP_KERNEL); | |
332 | if (!pagevec) | |
4db6e0b7 | 333 | break; |
607f31e8 TM |
334 | down_read(¤t->mm->mmap_sem); |
335 | result = get_user_pages(current, current->mm, user_addr, | |
584aa810 | 336 | npages, 1, 0, pagevec, NULL); |
607f31e8 | 337 | up_read(¤t->mm->mmap_sem); |
584aa810 | 338 | if (result < 0) |
749e146e | 339 | break; |
584aa810 | 340 | if ((unsigned)result < npages) { |
d9df8d6b TM |
341 | bytes = result * PAGE_SIZE; |
342 | if (bytes <= pgbase) { | |
584aa810 | 343 | nfs_direct_release_pages(pagevec, result); |
d9df8d6b TM |
344 | break; |
345 | } | |
346 | bytes -= pgbase; | |
584aa810 | 347 | npages = result; |
607f31e8 TM |
348 | } |
349 | ||
584aa810 FI |
350 | for (i = 0; i < npages; i++) { |
351 | struct nfs_page *req; | |
bf5fc402 | 352 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); |
584aa810 FI |
353 | /* XXX do we need to do the eof zeroing found in async_filler? */ |
354 | req = nfs_create_request(dreq->ctx, dreq->inode, | |
355 | pagevec[i], | |
356 | pgbase, req_len); | |
357 | if (IS_ERR(req)) { | |
584aa810 FI |
358 | result = PTR_ERR(req); |
359 | break; | |
360 | } | |
361 | req->wb_index = pos >> PAGE_SHIFT; | |
362 | req->wb_offset = pos & ~PAGE_MASK; | |
363 | if (!nfs_pageio_add_request(desc, req)) { | |
364 | result = desc->pg_error; | |
365 | nfs_release_request(req); | |
584aa810 FI |
366 | break; |
367 | } | |
368 | pgbase = 0; | |
369 | bytes -= req_len; | |
370 | started += req_len; | |
371 | user_addr += req_len; | |
372 | pos += req_len; | |
373 | count -= req_len; | |
374 | } | |
6d74743b TM |
375 | /* The nfs_page now hold references to these pages */ |
376 | nfs_direct_release_pages(pagevec, npages); | |
71e8cc00 | 377 | } while (count != 0 && result >= 0); |
607f31e8 | 378 | |
584aa810 FI |
379 | kfree(pagevec); |
380 | ||
607f31e8 | 381 | if (started) |
c216fd70 | 382 | return started; |
607f31e8 | 383 | return result < 0 ? (ssize_t) result : -EFAULT; |
1da177e4 LT |
384 | } |
385 | ||
19f73787 CL |
386 | static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, |
387 | const struct iovec *iov, | |
388 | unsigned long nr_segs, | |
389 | loff_t pos) | |
390 | { | |
584aa810 | 391 | struct nfs_pageio_descriptor desc; |
19f73787 CL |
392 | ssize_t result = -EINVAL; |
393 | size_t requested_bytes = 0; | |
394 | unsigned long seg; | |
395 | ||
584aa810 FI |
396 | nfs_pageio_init_read(&desc, dreq->inode, |
397 | &nfs_direct_read_completion_ops); | |
19f73787 | 398 | get_dreq(dreq); |
584aa810 | 399 | desc.pg_dreq = dreq; |
19f73787 CL |
400 | |
401 | for (seg = 0; seg < nr_segs; seg++) { | |
402 | const struct iovec *vec = &iov[seg]; | |
584aa810 | 403 | result = nfs_direct_read_schedule_segment(&desc, vec, pos); |
19f73787 CL |
404 | if (result < 0) |
405 | break; | |
406 | requested_bytes += result; | |
407 | if ((size_t)result < vec->iov_len) | |
408 | break; | |
409 | pos += vec->iov_len; | |
410 | } | |
411 | ||
584aa810 FI |
412 | nfs_pageio_complete(&desc); |
413 | ||
839f7ad6 CL |
414 | /* |
415 | * If no bytes were started, return the error, and let the | |
416 | * generic layer handle the completion. | |
417 | */ | |
418 | if (requested_bytes == 0) { | |
419 | nfs_direct_req_release(dreq); | |
420 | return result < 0 ? result : -EIO; | |
421 | } | |
422 | ||
19f73787 CL |
423 | if (put_dreq(dreq)) |
424 | nfs_direct_complete(dreq); | |
839f7ad6 | 425 | return 0; |
19f73787 CL |
426 | } |
427 | ||
c216fd70 CL |
428 | static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, |
429 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 430 | { |
f11ac8db | 431 | ssize_t result = -ENOMEM; |
99514f8f | 432 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 LT |
433 | struct nfs_direct_req *dreq; |
434 | ||
607f31e8 | 435 | dreq = nfs_direct_req_alloc(); |
f11ac8db TM |
436 | if (dreq == NULL) |
437 | goto out; | |
1da177e4 | 438 | |
91d5b470 | 439 | dreq->inode = inode; |
cd3758e3 | 440 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
f11ac8db TM |
441 | dreq->l_ctx = nfs_get_lock_context(dreq->ctx); |
442 | if (dreq->l_ctx == NULL) | |
443 | goto out_release; | |
487b8372 CL |
444 | if (!is_sync_kiocb(iocb)) |
445 | dreq->iocb = iocb; | |
1da177e4 | 446 | |
c216fd70 | 447 | result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos); |
607f31e8 TM |
448 | if (!result) |
449 | result = nfs_direct_wait(dreq); | |
2701d086 | 450 | NFS_I(inode)->read_io += result; |
f11ac8db | 451 | out_release: |
b4946ffb | 452 | nfs_direct_req_release(dreq); |
f11ac8db | 453 | out: |
1da177e4 LT |
454 | return result; |
455 | } | |
456 | ||
1d59d61f TM |
457 | static void nfs_inode_dio_write_done(struct inode *inode) |
458 | { | |
459 | nfs_zap_mapping(inode, inode->i_mapping); | |
460 | inode_dio_done(inode); | |
461 | } | |
462 | ||
fad61490 TM |
463 | #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
464 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) | |
465 | { | |
1763da12 FI |
466 | struct nfs_pageio_descriptor desc; |
467 | struct nfs_page *req, *tmp; | |
468 | LIST_HEAD(reqs); | |
469 | struct nfs_commit_info cinfo; | |
470 | LIST_HEAD(failed); | |
471 | ||
472 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
473 | pnfs_recover_commit_reqs(dreq->inode, &reqs, &cinfo); | |
474 | spin_lock(cinfo.lock); | |
475 | nfs_scan_commit_list(&cinfo.mds->list, &reqs, &cinfo, 0); | |
476 | spin_unlock(cinfo.lock); | |
1da177e4 | 477 | |
fad61490 | 478 | dreq->count = 0; |
607f31e8 TM |
479 | get_dreq(dreq); |
480 | ||
1763da12 FI |
481 | nfs_pageio_init_write(&desc, dreq->inode, FLUSH_STABLE, |
482 | &nfs_direct_write_completion_ops); | |
483 | desc.pg_dreq = dreq; | |
fedb595c | 484 | |
1763da12 FI |
485 | list_for_each_entry_safe(req, tmp, &reqs, wb_list) { |
486 | if (!nfs_pageio_add_request(&desc, req)) { | |
487 | nfs_list_add_request(req, &failed); | |
488 | spin_lock(cinfo.lock); | |
489 | dreq->flags = 0; | |
490 | dreq->error = -EIO; | |
491 | spin_unlock(cinfo.lock); | |
492 | } | |
493 | } | |
494 | nfs_pageio_complete(&desc); | |
fad61490 | 495 | |
04277086 | 496 | while (!list_empty(&failed)) |
1d1afcbc | 497 | nfs_unlock_and_release_request(req); |
fad61490 | 498 | |
1763da12 FI |
499 | if (put_dreq(dreq)) |
500 | nfs_direct_write_complete(dreq, dreq->inode); | |
c9d8f89d TM |
501 | } |
502 | ||
1763da12 | 503 | static void nfs_direct_commit_complete(struct nfs_commit_data *data) |
c9d8f89d | 504 | { |
0b7c0153 | 505 | struct nfs_direct_req *dreq = data->dreq; |
1763da12 FI |
506 | struct nfs_commit_info cinfo; |
507 | struct nfs_page *req; | |
c9d8f89d TM |
508 | int status = data->task.tk_status; |
509 | ||
1763da12 | 510 | nfs_init_cinfo_from_dreq(&cinfo, dreq); |
c9d8f89d | 511 | if (status < 0) { |
60fa3f76 | 512 | dprintk("NFS: %5u commit failed with error %d.\n", |
1763da12 | 513 | data->task.tk_pid, status); |
fad61490 | 514 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
60fa3f76 | 515 | } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { |
c9d8f89d | 516 | dprintk("NFS: %5u commit verify failed\n", data->task.tk_pid); |
fad61490 | 517 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
1da177e4 LT |
518 | } |
519 | ||
c9d8f89d | 520 | dprintk("NFS: %5u commit returned %d\n", data->task.tk_pid, status); |
1763da12 FI |
521 | while (!list_empty(&data->pages)) { |
522 | req = nfs_list_entry(data->pages.next); | |
523 | nfs_list_remove_request(req); | |
524 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) { | |
525 | /* Note the rewrite will go through mds */ | |
04277086 | 526 | kref_get(&req->wb_kref); |
1763da12 | 527 | nfs_mark_request_commit(req, NULL, &cinfo); |
04277086 | 528 | } |
1d1afcbc | 529 | nfs_unlock_and_release_request(req); |
1763da12 FI |
530 | } |
531 | ||
532 | if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) | |
533 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
534 | } |
535 | ||
1763da12 FI |
536 | static void nfs_direct_error_cleanup(struct nfs_inode *nfsi) |
537 | { | |
538 | /* There is no lock to clear */ | |
539 | } | |
540 | ||
541 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops = { | |
542 | .completion = nfs_direct_commit_complete, | |
543 | .error_cleanup = nfs_direct_error_cleanup, | |
fad61490 TM |
544 | }; |
545 | ||
546 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 547 | { |
1763da12 FI |
548 | int res; |
549 | struct nfs_commit_info cinfo; | |
550 | LIST_HEAD(mds_list); | |
551 | ||
552 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
553 | nfs_scan_commit(dreq->inode, &mds_list, &cinfo); | |
554 | res = nfs_generic_commit_list(dreq->inode, &mds_list, 0, &cinfo); | |
555 | if (res < 0) /* res == -ENOMEM */ | |
556 | nfs_direct_write_reschedule(dreq); | |
fad61490 | 557 | } |
1da177e4 | 558 | |
1763da12 | 559 | static void nfs_direct_write_schedule_work(struct work_struct *work) |
fad61490 | 560 | { |
1763da12 | 561 | struct nfs_direct_req *dreq = container_of(work, struct nfs_direct_req, work); |
fad61490 | 562 | int flags = dreq->flags; |
1da177e4 | 563 | |
fad61490 TM |
564 | dreq->flags = 0; |
565 | switch (flags) { | |
566 | case NFS_ODIRECT_DO_COMMIT: | |
567 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 568 | break; |
fad61490 TM |
569 | case NFS_ODIRECT_RESCHED_WRITES: |
570 | nfs_direct_write_reschedule(dreq); | |
571 | break; | |
572 | default: | |
1d59d61f | 573 | nfs_inode_dio_write_done(dreq->inode); |
fad61490 TM |
574 | nfs_direct_complete(dreq); |
575 | } | |
576 | } | |
1da177e4 | 577 | |
1763da12 | 578 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
fad61490 | 579 | { |
1763da12 | 580 | schedule_work(&dreq->work); /* Calls nfs_direct_write_schedule_work */ |
fad61490 | 581 | } |
1763da12 | 582 | |
fad61490 | 583 | #else |
24fc9211 BS |
584 | static void nfs_direct_write_schedule_work(struct work_struct *work) |
585 | { | |
586 | } | |
1da177e4 | 587 | |
fad61490 TM |
588 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
589 | { | |
1d59d61f | 590 | nfs_inode_dio_write_done(inode); |
fad61490 TM |
591 | nfs_direct_complete(dreq); |
592 | } | |
593 | #endif | |
1da177e4 | 594 | |
c9d8f89d TM |
595 | /* |
596 | * NB: Return the value of the first error return code. Subsequent | |
597 | * errors after the first one are ignored. | |
598 | */ | |
462d5b32 | 599 | /* |
607f31e8 TM |
600 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
601 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
602 | * bail and stop sending more writes. Write length accounting is | |
603 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
604 | * no requests have been sent, just return an error. | |
462d5b32 | 605 | */ |
1763da12 | 606 | static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc, |
02fe4946 | 607 | const struct iovec *iov, |
1763da12 | 608 | loff_t pos) |
462d5b32 | 609 | { |
1763da12 | 610 | struct nfs_direct_req *dreq = desc->pg_dreq; |
a8881f5a | 611 | struct nfs_open_context *ctx = dreq->ctx; |
3d4ff43d | 612 | struct inode *inode = ctx->dentry->d_inode; |
02fe4946 CL |
613 | unsigned long user_addr = (unsigned long)iov->iov_base; |
614 | size_t count = iov->iov_len; | |
462d5b32 | 615 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
616 | unsigned int pgbase; |
617 | int result; | |
618 | ssize_t started = 0; | |
1763da12 FI |
619 | struct page **pagevec = NULL; |
620 | unsigned int npages; | |
82b145c5 | 621 | |
1da177e4 | 622 | do { |
462d5b32 | 623 | size_t bytes; |
1763da12 | 624 | int i; |
462d5b32 | 625 | |
e9f7bee1 | 626 | pgbase = user_addr & ~PAGE_MASK; |
bf5fc402 | 627 | bytes = min(max_t(size_t, wsize, PAGE_SIZE), count); |
e9f7bee1 | 628 | |
607f31e8 | 629 | result = -ENOMEM; |
1763da12 FI |
630 | npages = nfs_page_array_len(pgbase, bytes); |
631 | if (!pagevec) | |
632 | pagevec = kmalloc(npages * sizeof(struct page *), GFP_KERNEL); | |
633 | if (!pagevec) | |
607f31e8 TM |
634 | break; |
635 | ||
607f31e8 TM |
636 | down_read(¤t->mm->mmap_sem); |
637 | result = get_user_pages(current, current->mm, user_addr, | |
1763da12 | 638 | npages, 0, 0, pagevec, NULL); |
607f31e8 | 639 | up_read(¤t->mm->mmap_sem); |
1763da12 | 640 | if (result < 0) |
749e146e | 641 | break; |
1763da12 FI |
642 | |
643 | if ((unsigned)result < npages) { | |
d9df8d6b TM |
644 | bytes = result * PAGE_SIZE; |
645 | if (bytes <= pgbase) { | |
1763da12 | 646 | nfs_direct_release_pages(pagevec, result); |
d9df8d6b TM |
647 | break; |
648 | } | |
649 | bytes -= pgbase; | |
1763da12 | 650 | npages = result; |
607f31e8 TM |
651 | } |
652 | ||
1763da12 FI |
653 | for (i = 0; i < npages; i++) { |
654 | struct nfs_page *req; | |
bf5fc402 | 655 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); |
1da177e4 | 656 | |
1763da12 FI |
657 | req = nfs_create_request(dreq->ctx, dreq->inode, |
658 | pagevec[i], | |
659 | pgbase, req_len); | |
660 | if (IS_ERR(req)) { | |
1763da12 FI |
661 | result = PTR_ERR(req); |
662 | break; | |
663 | } | |
664 | nfs_lock_request(req); | |
665 | req->wb_index = pos >> PAGE_SHIFT; | |
666 | req->wb_offset = pos & ~PAGE_MASK; | |
667 | if (!nfs_pageio_add_request(desc, req)) { | |
668 | result = desc->pg_error; | |
1d1afcbc | 669 | nfs_unlock_and_release_request(req); |
71e8cc00 | 670 | break; |
1763da12 FI |
671 | } |
672 | pgbase = 0; | |
673 | bytes -= req_len; | |
674 | started += req_len; | |
675 | user_addr += req_len; | |
676 | pos += req_len; | |
677 | count -= req_len; | |
678 | } | |
6d74743b TM |
679 | /* The nfs_page now hold references to these pages */ |
680 | nfs_direct_release_pages(pagevec, npages); | |
71e8cc00 | 681 | } while (count != 0 && result >= 0); |
607f31e8 | 682 | |
1763da12 FI |
683 | kfree(pagevec); |
684 | ||
607f31e8 | 685 | if (started) |
c216fd70 | 686 | return started; |
607f31e8 | 687 | return result < 0 ? (ssize_t) result : -EFAULT; |
462d5b32 | 688 | } |
1da177e4 | 689 | |
1763da12 FI |
690 | static void nfs_direct_write_completion(struct nfs_pgio_header *hdr) |
691 | { | |
692 | struct nfs_direct_req *dreq = hdr->dreq; | |
693 | struct nfs_commit_info cinfo; | |
694 | int bit = -1; | |
695 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
696 | ||
697 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) | |
698 | goto out_put; | |
699 | ||
700 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
701 | ||
702 | spin_lock(&dreq->lock); | |
703 | ||
704 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
705 | dreq->flags = 0; | |
706 | dreq->error = hdr->error; | |
707 | } | |
708 | if (dreq->error != 0) | |
709 | bit = NFS_IOHDR_ERROR; | |
710 | else { | |
711 | dreq->count += hdr->good_bytes; | |
712 | if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) { | |
713 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
714 | bit = NFS_IOHDR_NEED_RESCHED; | |
715 | } else if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) { | |
716 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) | |
717 | bit = NFS_IOHDR_NEED_RESCHED; | |
718 | else if (dreq->flags == 0) { | |
719 | memcpy(&dreq->verf, &req->wb_verf, | |
720 | sizeof(dreq->verf)); | |
721 | bit = NFS_IOHDR_NEED_COMMIT; | |
722 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
723 | } else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) { | |
724 | if (memcmp(&dreq->verf, &req->wb_verf, sizeof(dreq->verf))) { | |
725 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
726 | bit = NFS_IOHDR_NEED_RESCHED; | |
727 | } else | |
728 | bit = NFS_IOHDR_NEED_COMMIT; | |
729 | } | |
730 | } | |
731 | } | |
732 | spin_unlock(&dreq->lock); | |
733 | ||
734 | while (!list_empty(&hdr->pages)) { | |
735 | req = nfs_list_entry(hdr->pages.next); | |
736 | nfs_list_remove_request(req); | |
737 | switch (bit) { | |
738 | case NFS_IOHDR_NEED_RESCHED: | |
739 | case NFS_IOHDR_NEED_COMMIT: | |
04277086 | 740 | kref_get(&req->wb_kref); |
1763da12 | 741 | nfs_mark_request_commit(req, hdr->lseg, &cinfo); |
1763da12 | 742 | } |
1d1afcbc | 743 | nfs_unlock_and_release_request(req); |
1763da12 FI |
744 | } |
745 | ||
746 | out_put: | |
747 | if (put_dreq(dreq)) | |
748 | nfs_direct_write_complete(dreq, hdr->inode); | |
749 | hdr->release(hdr); | |
750 | } | |
751 | ||
3e9e0ca3 TM |
752 | static void nfs_write_sync_pgio_error(struct list_head *head) |
753 | { | |
754 | struct nfs_page *req; | |
755 | ||
756 | while (!list_empty(head)) { | |
757 | req = nfs_list_entry(head->next); | |
758 | nfs_list_remove_request(req); | |
1d1afcbc | 759 | nfs_unlock_and_release_request(req); |
3e9e0ca3 TM |
760 | } |
761 | } | |
762 | ||
1763da12 | 763 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = { |
3e9e0ca3 | 764 | .error_cleanup = nfs_write_sync_pgio_error, |
1763da12 FI |
765 | .init_hdr = nfs_direct_pgio_init, |
766 | .completion = nfs_direct_write_completion, | |
767 | }; | |
768 | ||
19f73787 CL |
769 | static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, |
770 | const struct iovec *iov, | |
771 | unsigned long nr_segs, | |
1763da12 | 772 | loff_t pos) |
19f73787 | 773 | { |
1763da12 | 774 | struct nfs_pageio_descriptor desc; |
1d59d61f | 775 | struct inode *inode = dreq->inode; |
19f73787 CL |
776 | ssize_t result = 0; |
777 | size_t requested_bytes = 0; | |
778 | unsigned long seg; | |
779 | ||
1d59d61f | 780 | nfs_pageio_init_write(&desc, inode, FLUSH_COND_STABLE, |
1763da12 FI |
781 | &nfs_direct_write_completion_ops); |
782 | desc.pg_dreq = dreq; | |
19f73787 | 783 | get_dreq(dreq); |
1d59d61f | 784 | atomic_inc(&inode->i_dio_count); |
19f73787 CL |
785 | |
786 | for (seg = 0; seg < nr_segs; seg++) { | |
787 | const struct iovec *vec = &iov[seg]; | |
1763da12 | 788 | result = nfs_direct_write_schedule_segment(&desc, vec, pos); |
19f73787 CL |
789 | if (result < 0) |
790 | break; | |
791 | requested_bytes += result; | |
792 | if ((size_t)result < vec->iov_len) | |
793 | break; | |
794 | pos += vec->iov_len; | |
795 | } | |
1763da12 | 796 | nfs_pageio_complete(&desc); |
2701d086 | 797 | NFS_I(dreq->inode)->write_io += desc.pg_bytes_written; |
19f73787 | 798 | |
839f7ad6 CL |
799 | /* |
800 | * If no bytes were started, return the error, and let the | |
801 | * generic layer handle the completion. | |
802 | */ | |
803 | if (requested_bytes == 0) { | |
1d59d61f | 804 | inode_dio_done(inode); |
839f7ad6 CL |
805 | nfs_direct_req_release(dreq); |
806 | return result < 0 ? result : -EIO; | |
807 | } | |
808 | ||
19f73787 CL |
809 | if (put_dreq(dreq)) |
810 | nfs_direct_write_complete(dreq, dreq->inode); | |
839f7ad6 | 811 | return 0; |
19f73787 CL |
812 | } |
813 | ||
c216fd70 CL |
814 | static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, |
815 | unsigned long nr_segs, loff_t pos, | |
816 | size_t count) | |
462d5b32 | 817 | { |
f11ac8db | 818 | ssize_t result = -ENOMEM; |
c89f2ee5 | 819 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 | 820 | struct nfs_direct_req *dreq; |
1da177e4 | 821 | |
607f31e8 | 822 | dreq = nfs_direct_req_alloc(); |
462d5b32 | 823 | if (!dreq) |
f11ac8db | 824 | goto out; |
1da177e4 | 825 | |
c89f2ee5 | 826 | dreq->inode = inode; |
cd3758e3 | 827 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
f11ac8db | 828 | dreq->l_ctx = nfs_get_lock_context(dreq->ctx); |
568a810d | 829 | if (dreq->l_ctx == NULL) |
f11ac8db | 830 | goto out_release; |
c89f2ee5 CL |
831 | if (!is_sync_kiocb(iocb)) |
832 | dreq->iocb = iocb; | |
1da177e4 | 833 | |
1763da12 | 834 | result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos); |
607f31e8 TM |
835 | if (!result) |
836 | result = nfs_direct_wait(dreq); | |
f11ac8db | 837 | out_release: |
b4946ffb | 838 | nfs_direct_req_release(dreq); |
f11ac8db | 839 | out: |
1da177e4 LT |
840 | return result; |
841 | } | |
842 | ||
843 | /** | |
844 | * nfs_file_direct_read - file direct read operation for NFS files | |
845 | * @iocb: target I/O control block | |
027445c3 BP |
846 | * @iov: vector of user buffers into which to read data |
847 | * @nr_segs: size of iov vector | |
88467055 | 848 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
849 | * |
850 | * We use this function for direct reads instead of calling | |
851 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
852 | * the request starts before the end of the file. For that check | |
853 | * to work, we must generate a GETATTR before each direct read, and | |
854 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 855 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
856 | * to do all reads the application wants, and the server will take |
857 | * care of managing the end of file boundary. | |
88467055 | 858 | * |
1da177e4 LT |
859 | * This function also eliminates unnecessarily updating the file's |
860 | * atime locally, as the NFS server sets the file's atime, and this | |
861 | * client must read the updated atime from the server back into its | |
862 | * cache. | |
863 | */ | |
027445c3 BP |
864 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
865 | unsigned long nr_segs, loff_t pos) | |
1da177e4 LT |
866 | { |
867 | ssize_t retval = -EINVAL; | |
1da177e4 | 868 | struct file *file = iocb->ki_filp; |
1da177e4 | 869 | struct address_space *mapping = file->f_mapping; |
c216fd70 CL |
870 | size_t count; |
871 | ||
872 | count = iov_length(iov, nr_segs); | |
873 | nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); | |
1da177e4 | 874 | |
6da24bc9 | 875 | dfprintk(FILE, "NFS: direct read(%s/%s, %zd@%Ld)\n", |
01cce933 JJS |
876 | file->f_path.dentry->d_parent->d_name.name, |
877 | file->f_path.dentry->d_name.name, | |
c216fd70 | 878 | count, (long long) pos); |
1da177e4 | 879 | |
1da177e4 LT |
880 | retval = 0; |
881 | if (!count) | |
882 | goto out; | |
883 | ||
29884df0 TM |
884 | retval = nfs_sync_mapping(mapping); |
885 | if (retval) | |
886 | goto out; | |
1da177e4 | 887 | |
7ec10f26 KK |
888 | task_io_account_read(count); |
889 | ||
c216fd70 | 890 | retval = nfs_direct_read(iocb, iov, nr_segs, pos); |
1da177e4 | 891 | if (retval > 0) |
0cdd80d0 | 892 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
893 | |
894 | out: | |
895 | return retval; | |
896 | } | |
897 | ||
898 | /** | |
899 | * nfs_file_direct_write - file direct write operation for NFS files | |
900 | * @iocb: target I/O control block | |
027445c3 BP |
901 | * @iov: vector of user buffers from which to write data |
902 | * @nr_segs: size of iov vector | |
88467055 | 903 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
904 | * |
905 | * We use this function for direct writes instead of calling | |
906 | * generic_file_aio_write() in order to avoid taking the inode | |
907 | * semaphore and updating the i_size. The NFS server will set | |
908 | * the new i_size and this client must read the updated size | |
909 | * back into its cache. We let the server do generic write | |
910 | * parameter checking and report problems. | |
911 | * | |
1da177e4 LT |
912 | * We eliminate local atime updates, see direct read above. |
913 | * | |
914 | * We avoid unnecessary page cache invalidations for normal cached | |
915 | * readers of this file. | |
916 | * | |
917 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
918 | * is no atomic O_APPEND write facility in the NFS protocol. | |
919 | */ | |
027445c3 BP |
920 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
921 | unsigned long nr_segs, loff_t pos) | |
1da177e4 | 922 | { |
070ea602 | 923 | ssize_t retval = -EINVAL; |
1da177e4 | 924 | struct file *file = iocb->ki_filp; |
1da177e4 | 925 | struct address_space *mapping = file->f_mapping; |
c216fd70 | 926 | size_t count; |
1da177e4 | 927 | |
c216fd70 CL |
928 | count = iov_length(iov, nr_segs); |
929 | nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); | |
930 | ||
6da24bc9 | 931 | dfprintk(FILE, "NFS: direct write(%s/%s, %zd@%Ld)\n", |
01cce933 JJS |
932 | file->f_path.dentry->d_parent->d_name.name, |
933 | file->f_path.dentry->d_name.name, | |
c216fd70 | 934 | count, (long long) pos); |
027445c3 | 935 | |
ce1a8e67 CL |
936 | retval = generic_write_checks(file, &pos, &count, 0); |
937 | if (retval) | |
1da177e4 | 938 | goto out; |
ce1a8e67 CL |
939 | |
940 | retval = -EINVAL; | |
941 | if ((ssize_t) count < 0) | |
1da177e4 | 942 | goto out; |
1da177e4 LT |
943 | retval = 0; |
944 | if (!count) | |
945 | goto out; | |
ce1a8e67 | 946 | |
29884df0 TM |
947 | retval = nfs_sync_mapping(mapping); |
948 | if (retval) | |
949 | goto out; | |
1da177e4 | 950 | |
7ec10f26 KK |
951 | task_io_account_write(count); |
952 | ||
c216fd70 | 953 | retval = nfs_direct_write(iocb, iov, nr_segs, pos, count); |
1763da12 FI |
954 | if (retval > 0) { |
955 | struct inode *inode = mapping->host; | |
9eafa8cc | 956 | |
ce1a8e67 | 957 | iocb->ki_pos = pos + retval; |
1763da12 FI |
958 | spin_lock(&inode->i_lock); |
959 | if (i_size_read(inode) < iocb->ki_pos) | |
960 | i_size_write(inode, iocb->ki_pos); | |
961 | spin_unlock(&inode->i_lock); | |
962 | } | |
1da177e4 LT |
963 | out: |
964 | return retval; | |
965 | } | |
966 | ||
88467055 CL |
967 | /** |
968 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
969 | * | |
970 | */ | |
f7b422b1 | 971 | int __init nfs_init_directcache(void) |
1da177e4 LT |
972 | { |
973 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
974 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
975 | 0, (SLAB_RECLAIM_ACCOUNT| |
976 | SLAB_MEM_SPREAD), | |
20c2df83 | 977 | NULL); |
1da177e4 LT |
978 | if (nfs_direct_cachep == NULL) |
979 | return -ENOMEM; | |
980 | ||
981 | return 0; | |
982 | } | |
983 | ||
88467055 | 984 | /** |
f7b422b1 | 985 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
986 | * |
987 | */ | |
266bee88 | 988 | void nfs_destroy_directcache(void) |
1da177e4 | 989 | { |
1a1d92c1 | 990 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 991 | } |