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> |
6296556f | 49 | #include <linux/module.h> |
1da177e4 LT |
50 | |
51 | #include <linux/nfs_fs.h> | |
52 | #include <linux/nfs_page.h> | |
53 | #include <linux/sunrpc/clnt.h> | |
54 | ||
1da177e4 | 55 | #include <asm/uaccess.h> |
60063497 | 56 | #include <linux/atomic.h> |
1da177e4 | 57 | |
8d5658c9 | 58 | #include "internal.h" |
91d5b470 | 59 | #include "iostat.h" |
1763da12 | 60 | #include "pnfs.h" |
91d5b470 | 61 | |
1da177e4 | 62 | #define NFSDBG_FACILITY NFSDBG_VFS |
1da177e4 | 63 | |
e18b890b | 64 | static struct kmem_cache *nfs_direct_cachep; |
1da177e4 LT |
65 | |
66 | /* | |
67 | * This represents a set of asynchronous requests that we're waiting on | |
68 | */ | |
69 | struct nfs_direct_req { | |
70 | struct kref kref; /* release manager */ | |
15ce4a0c CL |
71 | |
72 | /* I/O parameters */ | |
a8881f5a | 73 | struct nfs_open_context *ctx; /* file open context info */ |
f11ac8db | 74 | struct nfs_lock_context *l_ctx; /* Lock context info */ |
99514f8f | 75 | struct kiocb * iocb; /* controlling i/o request */ |
88467055 | 76 | struct inode * inode; /* target file of i/o */ |
15ce4a0c CL |
77 | |
78 | /* completion state */ | |
607f31e8 | 79 | atomic_t io_count; /* i/os we're waiting for */ |
15ce4a0c | 80 | spinlock_t lock; /* protect completion state */ |
15ce4a0c | 81 | ssize_t count, /* bytes actually processed */ |
35754bc0 | 82 | bytes_left, /* bytes left to be sent */ |
1da177e4 | 83 | error; /* any reported error */ |
d72b7a6b | 84 | struct completion completion; /* wait for i/o completion */ |
fad61490 TM |
85 | |
86 | /* commit state */ | |
1763da12 FI |
87 | struct nfs_mds_commit_info mds_cinfo; /* Storage for cinfo */ |
88 | struct pnfs_ds_commit_info ds_cinfo; /* Storage for cinfo */ | |
89 | struct work_struct work; | |
fad61490 TM |
90 | int flags; |
91 | #define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */ | |
92 | #define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */ | |
93 | struct nfs_writeverf verf; /* unstable write verifier */ | |
1da177e4 LT |
94 | }; |
95 | ||
1763da12 FI |
96 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops; |
97 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops; | |
fad61490 | 98 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); |
1763da12 | 99 | static void nfs_direct_write_schedule_work(struct work_struct *work); |
607f31e8 TM |
100 | |
101 | static inline void get_dreq(struct nfs_direct_req *dreq) | |
102 | { | |
103 | atomic_inc(&dreq->io_count); | |
104 | } | |
105 | ||
106 | static inline int put_dreq(struct nfs_direct_req *dreq) | |
107 | { | |
108 | return atomic_dec_and_test(&dreq->io_count); | |
109 | } | |
110 | ||
1da177e4 | 111 | /** |
b8a32e2b CL |
112 | * nfs_direct_IO - NFS address space operation for direct I/O |
113 | * @rw: direction (read or write) | |
114 | * @iocb: target I/O control block | |
115 | * @iov: array of vectors that define I/O buffer | |
116 | * @pos: offset in file to begin the operation | |
117 | * @nr_segs: size of iovec array | |
118 | * | |
119 | * The presence of this routine in the address space ops vector means | |
a564b8f0 MG |
120 | * the NFS client supports direct I/O. However, for most direct IO, we |
121 | * shunt off direct read and write requests before the VFS gets them, | |
122 | * so this method is only ever called for swap. | |
1da177e4 | 123 | */ |
b8a32e2b CL |
124 | ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) |
125 | { | |
a564b8f0 | 126 | #ifndef CONFIG_NFS_SWAP |
b8a32e2b | 127 | dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", |
01cce933 | 128 | iocb->ki_filp->f_path.dentry->d_name.name, |
e99170ff | 129 | (long long) pos, nr_segs); |
b8a32e2b CL |
130 | |
131 | return -EINVAL; | |
a564b8f0 MG |
132 | #else |
133 | VM_BUG_ON(iocb->ki_left != PAGE_SIZE); | |
134 | VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE); | |
135 | ||
136 | if (rw == READ || rw == KERNEL_READ) | |
137 | return nfs_file_direct_read(iocb, iov, nr_segs, pos, | |
138 | rw == READ ? true : false); | |
139 | return nfs_file_direct_write(iocb, iov, nr_segs, pos, | |
140 | rw == WRITE ? true : false); | |
141 | #endif /* CONFIG_NFS_SWAP */ | |
b8a32e2b CL |
142 | } |
143 | ||
749e146e | 144 | static void nfs_direct_release_pages(struct page **pages, unsigned int npages) |
9c93ab7d | 145 | { |
749e146e | 146 | unsigned int i; |
607f31e8 TM |
147 | for (i = 0; i < npages; i++) |
148 | page_cache_release(pages[i]); | |
6b45d858 TM |
149 | } |
150 | ||
1763da12 FI |
151 | void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo, |
152 | struct nfs_direct_req *dreq) | |
153 | { | |
154 | cinfo->lock = &dreq->lock; | |
155 | cinfo->mds = &dreq->mds_cinfo; | |
156 | cinfo->ds = &dreq->ds_cinfo; | |
157 | cinfo->dreq = dreq; | |
158 | cinfo->completion_ops = &nfs_direct_commit_completion_ops; | |
159 | } | |
160 | ||
93619e59 | 161 | static inline struct nfs_direct_req *nfs_direct_req_alloc(void) |
1da177e4 | 162 | { |
93619e59 CL |
163 | struct nfs_direct_req *dreq; |
164 | ||
292f3eee | 165 | dreq = kmem_cache_zalloc(nfs_direct_cachep, GFP_KERNEL); |
93619e59 CL |
166 | if (!dreq) |
167 | return NULL; | |
168 | ||
169 | kref_init(&dreq->kref); | |
607f31e8 | 170 | kref_get(&dreq->kref); |
d72b7a6b | 171 | init_completion(&dreq->completion); |
1763da12 FI |
172 | INIT_LIST_HEAD(&dreq->mds_cinfo.list); |
173 | INIT_WORK(&dreq->work, nfs_direct_write_schedule_work); | |
15ce4a0c | 174 | spin_lock_init(&dreq->lock); |
93619e59 CL |
175 | |
176 | return dreq; | |
1da177e4 LT |
177 | } |
178 | ||
b4946ffb | 179 | static void nfs_direct_req_free(struct kref *kref) |
1da177e4 LT |
180 | { |
181 | struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); | |
a8881f5a | 182 | |
f11ac8db TM |
183 | if (dreq->l_ctx != NULL) |
184 | nfs_put_lock_context(dreq->l_ctx); | |
a8881f5a TM |
185 | if (dreq->ctx != NULL) |
186 | put_nfs_open_context(dreq->ctx); | |
1da177e4 LT |
187 | kmem_cache_free(nfs_direct_cachep, dreq); |
188 | } | |
189 | ||
b4946ffb TM |
190 | static void nfs_direct_req_release(struct nfs_direct_req *dreq) |
191 | { | |
192 | kref_put(&dreq->kref, nfs_direct_req_free); | |
193 | } | |
194 | ||
6296556f PT |
195 | ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq) |
196 | { | |
197 | return dreq->bytes_left; | |
198 | } | |
199 | EXPORT_SYMBOL_GPL(nfs_dreq_bytes_left); | |
200 | ||
bc0fb201 CL |
201 | /* |
202 | * Collects and returns the final error value/byte-count. | |
203 | */ | |
204 | static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) | |
205 | { | |
15ce4a0c | 206 | ssize_t result = -EIOCBQUEUED; |
bc0fb201 CL |
207 | |
208 | /* Async requests don't wait here */ | |
209 | if (dreq->iocb) | |
210 | goto out; | |
211 | ||
150030b7 | 212 | result = wait_for_completion_killable(&dreq->completion); |
bc0fb201 CL |
213 | |
214 | if (!result) | |
15ce4a0c | 215 | result = dreq->error; |
bc0fb201 | 216 | if (!result) |
15ce4a0c | 217 | result = dreq->count; |
bc0fb201 CL |
218 | |
219 | out: | |
bc0fb201 CL |
220 | return (ssize_t) result; |
221 | } | |
222 | ||
63ab46ab | 223 | /* |
607f31e8 TM |
224 | * Synchronous I/O uses a stack-allocated iocb. Thus we can't trust |
225 | * the iocb is still valid here if this is a synchronous request. | |
63ab46ab CL |
226 | */ |
227 | static void nfs_direct_complete(struct nfs_direct_req *dreq) | |
228 | { | |
63ab46ab | 229 | if (dreq->iocb) { |
15ce4a0c | 230 | long res = (long) dreq->error; |
63ab46ab | 231 | if (!res) |
15ce4a0c | 232 | res = (long) dreq->count; |
63ab46ab | 233 | aio_complete(dreq->iocb, res, 0); |
d72b7a6b TM |
234 | } |
235 | complete_all(&dreq->completion); | |
63ab46ab | 236 | |
b4946ffb | 237 | nfs_direct_req_release(dreq); |
63ab46ab CL |
238 | } |
239 | ||
1385b811 | 240 | static void nfs_direct_readpage_release(struct nfs_page *req) |
1da177e4 | 241 | { |
584aa810 FI |
242 | dprintk("NFS: direct read done (%s/%lld %d@%lld)\n", |
243 | req->wb_context->dentry->d_inode->i_sb->s_id, | |
244 | (long long)NFS_FILEID(req->wb_context->dentry->d_inode), | |
245 | req->wb_bytes, | |
246 | (long long)req_offset(req)); | |
247 | nfs_release_request(req); | |
fdd1e74c TM |
248 | } |
249 | ||
584aa810 | 250 | static void nfs_direct_read_completion(struct nfs_pgio_header *hdr) |
fdd1e74c | 251 | { |
584aa810 FI |
252 | unsigned long bytes = 0; |
253 | struct nfs_direct_req *dreq = hdr->dreq; | |
fdd1e74c | 254 | |
584aa810 FI |
255 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) |
256 | goto out_put; | |
15ce4a0c CL |
257 | |
258 | spin_lock(&dreq->lock); | |
584aa810 FI |
259 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0)) |
260 | dreq->error = hdr->error; | |
261 | else | |
262 | dreq->count += hdr->good_bytes; | |
263 | spin_unlock(&dreq->lock); | |
264 | ||
4bd8b010 TM |
265 | while (!list_empty(&hdr->pages)) { |
266 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
267 | struct page *page = req->wb_page; | |
268 | ||
269 | if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) { | |
270 | if (bytes > hdr->good_bytes) | |
271 | zero_user(page, 0, PAGE_SIZE); | |
272 | else if (hdr->good_bytes - bytes < PAGE_SIZE) | |
273 | zero_user_segment(page, | |
274 | hdr->good_bytes & ~PAGE_MASK, | |
275 | PAGE_SIZE); | |
584aa810 | 276 | } |
4bd8b010 TM |
277 | if (!PageCompound(page)) { |
278 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
279 | if (bytes < hdr->good_bytes) | |
280 | set_page_dirty(page); | |
281 | } else | |
282 | set_page_dirty(page); | |
584aa810 | 283 | } |
4bd8b010 TM |
284 | bytes += req->wb_bytes; |
285 | nfs_list_remove_request(req); | |
286 | nfs_direct_readpage_release(req); | |
d4a8f367 | 287 | } |
584aa810 | 288 | out_put: |
607f31e8 TM |
289 | if (put_dreq(dreq)) |
290 | nfs_direct_complete(dreq); | |
584aa810 | 291 | hdr->release(hdr); |
1da177e4 LT |
292 | } |
293 | ||
3e9e0ca3 | 294 | static void nfs_read_sync_pgio_error(struct list_head *head) |
cd841605 | 295 | { |
584aa810 | 296 | struct nfs_page *req; |
cd841605 | 297 | |
584aa810 FI |
298 | while (!list_empty(head)) { |
299 | req = nfs_list_entry(head->next); | |
300 | nfs_list_remove_request(req); | |
301 | nfs_release_request(req); | |
302 | } | |
cd841605 FI |
303 | } |
304 | ||
584aa810 FI |
305 | static void nfs_direct_pgio_init(struct nfs_pgio_header *hdr) |
306 | { | |
307 | get_dreq(hdr->dreq); | |
308 | } | |
309 | ||
310 | static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = { | |
3e9e0ca3 | 311 | .error_cleanup = nfs_read_sync_pgio_error, |
584aa810 FI |
312 | .init_hdr = nfs_direct_pgio_init, |
313 | .completion = nfs_direct_read_completion, | |
314 | }; | |
315 | ||
d4cc948b | 316 | /* |
607f31e8 TM |
317 | * For each rsize'd chunk of the user's buffer, dispatch an NFS READ |
318 | * operation. If nfs_readdata_alloc() or get_user_pages() fails, | |
319 | * bail and stop sending more reads. Read length accounting is | |
320 | * handled automatically by nfs_direct_read_result(). Otherwise, if | |
321 | * no requests have been sent, just return an error. | |
1da177e4 | 322 | */ |
584aa810 | 323 | static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc, |
02fe4946 | 324 | const struct iovec *iov, |
a564b8f0 | 325 | loff_t pos, bool uio) |
1da177e4 | 326 | { |
584aa810 | 327 | struct nfs_direct_req *dreq = desc->pg_dreq; |
a8881f5a | 328 | struct nfs_open_context *ctx = dreq->ctx; |
3d4ff43d | 329 | struct inode *inode = ctx->dentry->d_inode; |
02fe4946 CL |
330 | unsigned long user_addr = (unsigned long)iov->iov_base; |
331 | size_t count = iov->iov_len; | |
5dd602f2 | 332 | size_t rsize = NFS_SERVER(inode)->rsize; |
607f31e8 TM |
333 | unsigned int pgbase; |
334 | int result; | |
335 | ssize_t started = 0; | |
584aa810 FI |
336 | struct page **pagevec = NULL; |
337 | unsigned int npages; | |
607f31e8 | 338 | |
1da177e4 | 339 | do { |
5dd602f2 | 340 | size_t bytes; |
584aa810 | 341 | int i; |
1da177e4 | 342 | |
e9f7bee1 | 343 | pgbase = user_addr & ~PAGE_MASK; |
bf5fc402 | 344 | bytes = min(max_t(size_t, rsize, PAGE_SIZE), count); |
e9f7bee1 | 345 | |
607f31e8 | 346 | result = -ENOMEM; |
584aa810 FI |
347 | npages = nfs_page_array_len(pgbase, bytes); |
348 | if (!pagevec) | |
349 | pagevec = kmalloc(npages * sizeof(struct page *), | |
350 | GFP_KERNEL); | |
351 | if (!pagevec) | |
4db6e0b7 | 352 | break; |
a564b8f0 MG |
353 | if (uio) { |
354 | down_read(¤t->mm->mmap_sem); | |
355 | result = get_user_pages(current, current->mm, user_addr, | |
584aa810 | 356 | npages, 1, 0, pagevec, NULL); |
a564b8f0 MG |
357 | up_read(¤t->mm->mmap_sem); |
358 | if (result < 0) | |
359 | break; | |
360 | } else { | |
361 | WARN_ON(npages != 1); | |
362 | result = get_kernel_page(user_addr, 1, pagevec); | |
363 | if (WARN_ON(result != 1)) | |
364 | break; | |
365 | } | |
366 | ||
584aa810 | 367 | if ((unsigned)result < npages) { |
d9df8d6b TM |
368 | bytes = result * PAGE_SIZE; |
369 | if (bytes <= pgbase) { | |
584aa810 | 370 | nfs_direct_release_pages(pagevec, result); |
d9df8d6b TM |
371 | break; |
372 | } | |
373 | bytes -= pgbase; | |
584aa810 | 374 | npages = result; |
607f31e8 TM |
375 | } |
376 | ||
584aa810 FI |
377 | for (i = 0; i < npages; i++) { |
378 | struct nfs_page *req; | |
bf5fc402 | 379 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); |
584aa810 FI |
380 | /* XXX do we need to do the eof zeroing found in async_filler? */ |
381 | req = nfs_create_request(dreq->ctx, dreq->inode, | |
382 | pagevec[i], | |
383 | pgbase, req_len); | |
384 | if (IS_ERR(req)) { | |
584aa810 FI |
385 | result = PTR_ERR(req); |
386 | break; | |
387 | } | |
388 | req->wb_index = pos >> PAGE_SHIFT; | |
389 | req->wb_offset = pos & ~PAGE_MASK; | |
390 | if (!nfs_pageio_add_request(desc, req)) { | |
391 | result = desc->pg_error; | |
392 | nfs_release_request(req); | |
584aa810 FI |
393 | break; |
394 | } | |
395 | pgbase = 0; | |
396 | bytes -= req_len; | |
397 | started += req_len; | |
398 | user_addr += req_len; | |
399 | pos += req_len; | |
400 | count -= req_len; | |
35754bc0 | 401 | dreq->bytes_left -= req_len; |
584aa810 | 402 | } |
6d74743b TM |
403 | /* The nfs_page now hold references to these pages */ |
404 | nfs_direct_release_pages(pagevec, npages); | |
71e8cc00 | 405 | } while (count != 0 && result >= 0); |
607f31e8 | 406 | |
584aa810 FI |
407 | kfree(pagevec); |
408 | ||
607f31e8 | 409 | if (started) |
c216fd70 | 410 | return started; |
607f31e8 | 411 | return result < 0 ? (ssize_t) result : -EFAULT; |
1da177e4 LT |
412 | } |
413 | ||
19f73787 CL |
414 | static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, |
415 | const struct iovec *iov, | |
416 | unsigned long nr_segs, | |
a564b8f0 | 417 | loff_t pos, bool uio) |
19f73787 | 418 | { |
584aa810 | 419 | struct nfs_pageio_descriptor desc; |
19f73787 CL |
420 | ssize_t result = -EINVAL; |
421 | size_t requested_bytes = 0; | |
422 | unsigned long seg; | |
423 | ||
59948db3 | 424 | NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode, |
584aa810 | 425 | &nfs_direct_read_completion_ops); |
19f73787 | 426 | get_dreq(dreq); |
584aa810 | 427 | desc.pg_dreq = dreq; |
19f73787 CL |
428 | |
429 | for (seg = 0; seg < nr_segs; seg++) { | |
430 | const struct iovec *vec = &iov[seg]; | |
a564b8f0 | 431 | result = nfs_direct_read_schedule_segment(&desc, vec, pos, uio); |
19f73787 CL |
432 | if (result < 0) |
433 | break; | |
434 | requested_bytes += result; | |
435 | if ((size_t)result < vec->iov_len) | |
436 | break; | |
437 | pos += vec->iov_len; | |
438 | } | |
439 | ||
584aa810 FI |
440 | nfs_pageio_complete(&desc); |
441 | ||
839f7ad6 CL |
442 | /* |
443 | * If no bytes were started, return the error, and let the | |
444 | * generic layer handle the completion. | |
445 | */ | |
446 | if (requested_bytes == 0) { | |
447 | nfs_direct_req_release(dreq); | |
448 | return result < 0 ? result : -EIO; | |
449 | } | |
450 | ||
19f73787 CL |
451 | if (put_dreq(dreq)) |
452 | nfs_direct_complete(dreq); | |
839f7ad6 | 453 | return 0; |
19f73787 CL |
454 | } |
455 | ||
c216fd70 | 456 | static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, |
a564b8f0 | 457 | unsigned long nr_segs, loff_t pos, bool uio) |
1da177e4 | 458 | { |
f11ac8db | 459 | ssize_t result = -ENOMEM; |
99514f8f | 460 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
1da177e4 | 461 | struct nfs_direct_req *dreq; |
b3c54de6 | 462 | struct nfs_lock_context *l_ctx; |
1da177e4 | 463 | |
607f31e8 | 464 | dreq = nfs_direct_req_alloc(); |
f11ac8db TM |
465 | if (dreq == NULL) |
466 | goto out; | |
1da177e4 | 467 | |
91d5b470 | 468 | dreq->inode = inode; |
35754bc0 | 469 | dreq->bytes_left = iov_length(iov, nr_segs); |
cd3758e3 | 470 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
b3c54de6 TM |
471 | l_ctx = nfs_get_lock_context(dreq->ctx); |
472 | if (IS_ERR(l_ctx)) { | |
473 | result = PTR_ERR(l_ctx); | |
f11ac8db | 474 | goto out_release; |
b3c54de6 TM |
475 | } |
476 | dreq->l_ctx = l_ctx; | |
487b8372 CL |
477 | if (!is_sync_kiocb(iocb)) |
478 | dreq->iocb = iocb; | |
1da177e4 | 479 | |
7acdb026 | 480 | NFS_I(inode)->read_io += iov_length(iov, nr_segs); |
a564b8f0 | 481 | result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio); |
607f31e8 TM |
482 | if (!result) |
483 | result = nfs_direct_wait(dreq); | |
f11ac8db | 484 | out_release: |
b4946ffb | 485 | nfs_direct_req_release(dreq); |
f11ac8db | 486 | out: |
1da177e4 LT |
487 | return result; |
488 | } | |
489 | ||
1d59d61f TM |
490 | static void nfs_inode_dio_write_done(struct inode *inode) |
491 | { | |
492 | nfs_zap_mapping(inode, inode->i_mapping); | |
493 | inode_dio_done(inode); | |
494 | } | |
495 | ||
89d77c8f | 496 | #if IS_ENABLED(CONFIG_NFS_V3) || IS_ENABLED(CONFIG_NFS_V4) |
fad61490 TM |
497 | static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) |
498 | { | |
1763da12 FI |
499 | struct nfs_pageio_descriptor desc; |
500 | struct nfs_page *req, *tmp; | |
501 | LIST_HEAD(reqs); | |
502 | struct nfs_commit_info cinfo; | |
503 | LIST_HEAD(failed); | |
504 | ||
505 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
506 | pnfs_recover_commit_reqs(dreq->inode, &reqs, &cinfo); | |
507 | spin_lock(cinfo.lock); | |
508 | nfs_scan_commit_list(&cinfo.mds->list, &reqs, &cinfo, 0); | |
509 | spin_unlock(cinfo.lock); | |
1da177e4 | 510 | |
fad61490 | 511 | dreq->count = 0; |
607f31e8 TM |
512 | get_dreq(dreq); |
513 | ||
c95908e4 | 514 | NFS_PROTO(dreq->inode)->write_pageio_init(&desc, dreq->inode, FLUSH_STABLE, |
1763da12 FI |
515 | &nfs_direct_write_completion_ops); |
516 | desc.pg_dreq = dreq; | |
fedb595c | 517 | |
1763da12 FI |
518 | list_for_each_entry_safe(req, tmp, &reqs, wb_list) { |
519 | if (!nfs_pageio_add_request(&desc, req)) { | |
4035c248 | 520 | nfs_list_remove_request(req); |
1763da12 FI |
521 | nfs_list_add_request(req, &failed); |
522 | spin_lock(cinfo.lock); | |
523 | dreq->flags = 0; | |
524 | dreq->error = -EIO; | |
525 | spin_unlock(cinfo.lock); | |
526 | } | |
5a695da2 | 527 | nfs_release_request(req); |
1763da12 FI |
528 | } |
529 | nfs_pageio_complete(&desc); | |
fad61490 | 530 | |
4035c248 TM |
531 | while (!list_empty(&failed)) { |
532 | req = nfs_list_entry(failed.next); | |
533 | nfs_list_remove_request(req); | |
1d1afcbc | 534 | nfs_unlock_and_release_request(req); |
4035c248 | 535 | } |
fad61490 | 536 | |
1763da12 FI |
537 | if (put_dreq(dreq)) |
538 | nfs_direct_write_complete(dreq, dreq->inode); | |
c9d8f89d TM |
539 | } |
540 | ||
1763da12 | 541 | static void nfs_direct_commit_complete(struct nfs_commit_data *data) |
c9d8f89d | 542 | { |
0b7c0153 | 543 | struct nfs_direct_req *dreq = data->dreq; |
1763da12 FI |
544 | struct nfs_commit_info cinfo; |
545 | struct nfs_page *req; | |
c9d8f89d TM |
546 | int status = data->task.tk_status; |
547 | ||
1763da12 | 548 | nfs_init_cinfo_from_dreq(&cinfo, dreq); |
c9d8f89d | 549 | if (status < 0) { |
60fa3f76 | 550 | dprintk("NFS: %5u commit failed with error %d.\n", |
1763da12 | 551 | data->task.tk_pid, status); |
fad61490 | 552 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
60fa3f76 | 553 | } else if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) { |
c9d8f89d | 554 | dprintk("NFS: %5u commit verify failed\n", data->task.tk_pid); |
fad61490 | 555 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
1da177e4 LT |
556 | } |
557 | ||
c9d8f89d | 558 | dprintk("NFS: %5u commit returned %d\n", data->task.tk_pid, status); |
1763da12 FI |
559 | while (!list_empty(&data->pages)) { |
560 | req = nfs_list_entry(data->pages.next); | |
561 | nfs_list_remove_request(req); | |
562 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) { | |
563 | /* Note the rewrite will go through mds */ | |
564 | nfs_mark_request_commit(req, NULL, &cinfo); | |
906369e4 FI |
565 | } else |
566 | nfs_release_request(req); | |
1d1afcbc | 567 | nfs_unlock_and_release_request(req); |
1763da12 FI |
568 | } |
569 | ||
570 | if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) | |
571 | nfs_direct_write_complete(dreq, data->inode); | |
1da177e4 LT |
572 | } |
573 | ||
1763da12 FI |
574 | static void nfs_direct_error_cleanup(struct nfs_inode *nfsi) |
575 | { | |
576 | /* There is no lock to clear */ | |
577 | } | |
578 | ||
579 | static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops = { | |
580 | .completion = nfs_direct_commit_complete, | |
581 | .error_cleanup = nfs_direct_error_cleanup, | |
fad61490 TM |
582 | }; |
583 | ||
584 | static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq) | |
1da177e4 | 585 | { |
1763da12 FI |
586 | int res; |
587 | struct nfs_commit_info cinfo; | |
588 | LIST_HEAD(mds_list); | |
589 | ||
590 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
591 | nfs_scan_commit(dreq->inode, &mds_list, &cinfo); | |
592 | res = nfs_generic_commit_list(dreq->inode, &mds_list, 0, &cinfo); | |
593 | if (res < 0) /* res == -ENOMEM */ | |
594 | nfs_direct_write_reschedule(dreq); | |
fad61490 | 595 | } |
1da177e4 | 596 | |
1763da12 | 597 | static void nfs_direct_write_schedule_work(struct work_struct *work) |
fad61490 | 598 | { |
1763da12 | 599 | struct nfs_direct_req *dreq = container_of(work, struct nfs_direct_req, work); |
fad61490 | 600 | int flags = dreq->flags; |
1da177e4 | 601 | |
fad61490 TM |
602 | dreq->flags = 0; |
603 | switch (flags) { | |
604 | case NFS_ODIRECT_DO_COMMIT: | |
605 | nfs_direct_commit_schedule(dreq); | |
1da177e4 | 606 | break; |
fad61490 TM |
607 | case NFS_ODIRECT_RESCHED_WRITES: |
608 | nfs_direct_write_reschedule(dreq); | |
609 | break; | |
610 | default: | |
1d59d61f | 611 | nfs_inode_dio_write_done(dreq->inode); |
fad61490 TM |
612 | nfs_direct_complete(dreq); |
613 | } | |
614 | } | |
1da177e4 | 615 | |
1763da12 | 616 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
fad61490 | 617 | { |
1763da12 | 618 | schedule_work(&dreq->work); /* Calls nfs_direct_write_schedule_work */ |
fad61490 | 619 | } |
1763da12 | 620 | |
fad61490 | 621 | #else |
24fc9211 BS |
622 | static void nfs_direct_write_schedule_work(struct work_struct *work) |
623 | { | |
624 | } | |
1da177e4 | 625 | |
fad61490 TM |
626 | static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) |
627 | { | |
1d59d61f | 628 | nfs_inode_dio_write_done(inode); |
fad61490 TM |
629 | nfs_direct_complete(dreq); |
630 | } | |
631 | #endif | |
1da177e4 | 632 | |
c9d8f89d TM |
633 | /* |
634 | * NB: Return the value of the first error return code. Subsequent | |
635 | * errors after the first one are ignored. | |
636 | */ | |
462d5b32 | 637 | /* |
607f31e8 TM |
638 | * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE |
639 | * operation. If nfs_writedata_alloc() or get_user_pages() fails, | |
640 | * bail and stop sending more writes. Write length accounting is | |
641 | * handled automatically by nfs_direct_write_result(). Otherwise, if | |
642 | * no requests have been sent, just return an error. | |
462d5b32 | 643 | */ |
1763da12 | 644 | static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc, |
02fe4946 | 645 | const struct iovec *iov, |
a564b8f0 | 646 | loff_t pos, bool uio) |
462d5b32 | 647 | { |
1763da12 | 648 | struct nfs_direct_req *dreq = desc->pg_dreq; |
a8881f5a | 649 | struct nfs_open_context *ctx = dreq->ctx; |
3d4ff43d | 650 | struct inode *inode = ctx->dentry->d_inode; |
02fe4946 CL |
651 | unsigned long user_addr = (unsigned long)iov->iov_base; |
652 | size_t count = iov->iov_len; | |
462d5b32 | 653 | size_t wsize = NFS_SERVER(inode)->wsize; |
607f31e8 TM |
654 | unsigned int pgbase; |
655 | int result; | |
656 | ssize_t started = 0; | |
1763da12 FI |
657 | struct page **pagevec = NULL; |
658 | unsigned int npages; | |
82b145c5 | 659 | |
1da177e4 | 660 | do { |
462d5b32 | 661 | size_t bytes; |
1763da12 | 662 | int i; |
462d5b32 | 663 | |
e9f7bee1 | 664 | pgbase = user_addr & ~PAGE_MASK; |
bf5fc402 | 665 | bytes = min(max_t(size_t, wsize, PAGE_SIZE), count); |
e9f7bee1 | 666 | |
607f31e8 | 667 | result = -ENOMEM; |
1763da12 FI |
668 | npages = nfs_page_array_len(pgbase, bytes); |
669 | if (!pagevec) | |
670 | pagevec = kmalloc(npages * sizeof(struct page *), GFP_KERNEL); | |
671 | if (!pagevec) | |
607f31e8 TM |
672 | break; |
673 | ||
a564b8f0 MG |
674 | if (uio) { |
675 | down_read(¤t->mm->mmap_sem); | |
676 | result = get_user_pages(current, current->mm, user_addr, | |
677 | npages, 0, 0, pagevec, NULL); | |
678 | up_read(¤t->mm->mmap_sem); | |
679 | if (result < 0) | |
680 | break; | |
681 | } else { | |
682 | WARN_ON(npages != 1); | |
683 | result = get_kernel_page(user_addr, 0, pagevec); | |
684 | if (WARN_ON(result != 1)) | |
685 | break; | |
686 | } | |
1763da12 FI |
687 | |
688 | if ((unsigned)result < npages) { | |
d9df8d6b TM |
689 | bytes = result * PAGE_SIZE; |
690 | if (bytes <= pgbase) { | |
1763da12 | 691 | nfs_direct_release_pages(pagevec, result); |
d9df8d6b TM |
692 | break; |
693 | } | |
694 | bytes -= pgbase; | |
1763da12 | 695 | npages = result; |
607f31e8 TM |
696 | } |
697 | ||
1763da12 FI |
698 | for (i = 0; i < npages; i++) { |
699 | struct nfs_page *req; | |
bf5fc402 | 700 | unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase); |
1da177e4 | 701 | |
1763da12 FI |
702 | req = nfs_create_request(dreq->ctx, dreq->inode, |
703 | pagevec[i], | |
704 | pgbase, req_len); | |
705 | if (IS_ERR(req)) { | |
1763da12 FI |
706 | result = PTR_ERR(req); |
707 | break; | |
708 | } | |
709 | nfs_lock_request(req); | |
710 | req->wb_index = pos >> PAGE_SHIFT; | |
711 | req->wb_offset = pos & ~PAGE_MASK; | |
712 | if (!nfs_pageio_add_request(desc, req)) { | |
713 | result = desc->pg_error; | |
1d1afcbc | 714 | nfs_unlock_and_release_request(req); |
71e8cc00 | 715 | break; |
1763da12 FI |
716 | } |
717 | pgbase = 0; | |
718 | bytes -= req_len; | |
719 | started += req_len; | |
720 | user_addr += req_len; | |
721 | pos += req_len; | |
722 | count -= req_len; | |
35754bc0 | 723 | dreq->bytes_left -= req_len; |
1763da12 | 724 | } |
6d74743b TM |
725 | /* The nfs_page now hold references to these pages */ |
726 | nfs_direct_release_pages(pagevec, npages); | |
71e8cc00 | 727 | } while (count != 0 && result >= 0); |
607f31e8 | 728 | |
1763da12 FI |
729 | kfree(pagevec); |
730 | ||
607f31e8 | 731 | if (started) |
c216fd70 | 732 | return started; |
607f31e8 | 733 | return result < 0 ? (ssize_t) result : -EFAULT; |
462d5b32 | 734 | } |
1da177e4 | 735 | |
1763da12 FI |
736 | static void nfs_direct_write_completion(struct nfs_pgio_header *hdr) |
737 | { | |
738 | struct nfs_direct_req *dreq = hdr->dreq; | |
739 | struct nfs_commit_info cinfo; | |
740 | int bit = -1; | |
741 | struct nfs_page *req = nfs_list_entry(hdr->pages.next); | |
742 | ||
743 | if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) | |
744 | goto out_put; | |
745 | ||
746 | nfs_init_cinfo_from_dreq(&cinfo, dreq); | |
747 | ||
748 | spin_lock(&dreq->lock); | |
749 | ||
750 | if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { | |
751 | dreq->flags = 0; | |
752 | dreq->error = hdr->error; | |
753 | } | |
754 | if (dreq->error != 0) | |
755 | bit = NFS_IOHDR_ERROR; | |
756 | else { | |
757 | dreq->count += hdr->good_bytes; | |
758 | if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) { | |
759 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; | |
760 | bit = NFS_IOHDR_NEED_RESCHED; | |
761 | } else if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) { | |
762 | if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) | |
763 | bit = NFS_IOHDR_NEED_RESCHED; | |
764 | else if (dreq->flags == 0) { | |
9bce008b | 765 | memcpy(&dreq->verf, hdr->verf, |
1763da12 FI |
766 | sizeof(dreq->verf)); |
767 | bit = NFS_IOHDR_NEED_COMMIT; | |
768 | dreq->flags = NFS_ODIRECT_DO_COMMIT; | |
769 | } else if (dreq->flags == NFS_ODIRECT_DO_COMMIT) { | |
9bce008b | 770 | if (memcmp(&dreq->verf, hdr->verf, sizeof(dreq->verf))) { |
1763da12 FI |
771 | dreq->flags = NFS_ODIRECT_RESCHED_WRITES; |
772 | bit = NFS_IOHDR_NEED_RESCHED; | |
773 | } else | |
774 | bit = NFS_IOHDR_NEED_COMMIT; | |
775 | } | |
776 | } | |
777 | } | |
778 | spin_unlock(&dreq->lock); | |
779 | ||
780 | while (!list_empty(&hdr->pages)) { | |
781 | req = nfs_list_entry(hdr->pages.next); | |
782 | nfs_list_remove_request(req); | |
783 | switch (bit) { | |
784 | case NFS_IOHDR_NEED_RESCHED: | |
785 | case NFS_IOHDR_NEED_COMMIT: | |
04277086 | 786 | kref_get(&req->wb_kref); |
1763da12 | 787 | nfs_mark_request_commit(req, hdr->lseg, &cinfo); |
1763da12 | 788 | } |
1d1afcbc | 789 | nfs_unlock_and_release_request(req); |
1763da12 FI |
790 | } |
791 | ||
792 | out_put: | |
793 | if (put_dreq(dreq)) | |
794 | nfs_direct_write_complete(dreq, hdr->inode); | |
795 | hdr->release(hdr); | |
796 | } | |
797 | ||
3e9e0ca3 TM |
798 | static void nfs_write_sync_pgio_error(struct list_head *head) |
799 | { | |
800 | struct nfs_page *req; | |
801 | ||
802 | while (!list_empty(head)) { | |
803 | req = nfs_list_entry(head->next); | |
804 | nfs_list_remove_request(req); | |
1d1afcbc | 805 | nfs_unlock_and_release_request(req); |
3e9e0ca3 TM |
806 | } |
807 | } | |
808 | ||
1763da12 | 809 | static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = { |
3e9e0ca3 | 810 | .error_cleanup = nfs_write_sync_pgio_error, |
1763da12 FI |
811 | .init_hdr = nfs_direct_pgio_init, |
812 | .completion = nfs_direct_write_completion, | |
813 | }; | |
814 | ||
19f73787 CL |
815 | static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, |
816 | const struct iovec *iov, | |
817 | unsigned long nr_segs, | |
a564b8f0 | 818 | loff_t pos, bool uio) |
19f73787 | 819 | { |
1763da12 | 820 | struct nfs_pageio_descriptor desc; |
1d59d61f | 821 | struct inode *inode = dreq->inode; |
19f73787 CL |
822 | ssize_t result = 0; |
823 | size_t requested_bytes = 0; | |
824 | unsigned long seg; | |
825 | ||
c95908e4 | 826 | NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE, |
1763da12 FI |
827 | &nfs_direct_write_completion_ops); |
828 | desc.pg_dreq = dreq; | |
19f73787 | 829 | get_dreq(dreq); |
1d59d61f | 830 | atomic_inc(&inode->i_dio_count); |
19f73787 | 831 | |
7acdb026 | 832 | NFS_I(dreq->inode)->write_io += iov_length(iov, nr_segs); |
19f73787 CL |
833 | for (seg = 0; seg < nr_segs; seg++) { |
834 | const struct iovec *vec = &iov[seg]; | |
a564b8f0 | 835 | result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio); |
19f73787 CL |
836 | if (result < 0) |
837 | break; | |
838 | requested_bytes += result; | |
839 | if ((size_t)result < vec->iov_len) | |
840 | break; | |
841 | pos += vec->iov_len; | |
842 | } | |
1763da12 | 843 | nfs_pageio_complete(&desc); |
19f73787 | 844 | |
839f7ad6 CL |
845 | /* |
846 | * If no bytes were started, return the error, and let the | |
847 | * generic layer handle the completion. | |
848 | */ | |
849 | if (requested_bytes == 0) { | |
1d59d61f | 850 | inode_dio_done(inode); |
839f7ad6 CL |
851 | nfs_direct_req_release(dreq); |
852 | return result < 0 ? result : -EIO; | |
853 | } | |
854 | ||
19f73787 CL |
855 | if (put_dreq(dreq)) |
856 | nfs_direct_write_complete(dreq, dreq->inode); | |
839f7ad6 | 857 | return 0; |
19f73787 CL |
858 | } |
859 | ||
c216fd70 CL |
860 | static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov, |
861 | unsigned long nr_segs, loff_t pos, | |
a564b8f0 | 862 | size_t count, bool uio) |
462d5b32 | 863 | { |
f11ac8db | 864 | ssize_t result = -ENOMEM; |
c89f2ee5 | 865 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
462d5b32 | 866 | struct nfs_direct_req *dreq; |
b3c54de6 | 867 | struct nfs_lock_context *l_ctx; |
1da177e4 | 868 | |
607f31e8 | 869 | dreq = nfs_direct_req_alloc(); |
462d5b32 | 870 | if (!dreq) |
f11ac8db | 871 | goto out; |
1da177e4 | 872 | |
c89f2ee5 | 873 | dreq->inode = inode; |
35754bc0 | 874 | dreq->bytes_left = count; |
cd3758e3 | 875 | dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); |
b3c54de6 TM |
876 | l_ctx = nfs_get_lock_context(dreq->ctx); |
877 | if (IS_ERR(l_ctx)) { | |
878 | result = PTR_ERR(l_ctx); | |
f11ac8db | 879 | goto out_release; |
b3c54de6 TM |
880 | } |
881 | dreq->l_ctx = l_ctx; | |
c89f2ee5 CL |
882 | if (!is_sync_kiocb(iocb)) |
883 | dreq->iocb = iocb; | |
1da177e4 | 884 | |
a564b8f0 | 885 | result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, uio); |
607f31e8 TM |
886 | if (!result) |
887 | result = nfs_direct_wait(dreq); | |
f11ac8db | 888 | out_release: |
b4946ffb | 889 | nfs_direct_req_release(dreq); |
f11ac8db | 890 | out: |
1da177e4 LT |
891 | return result; |
892 | } | |
893 | ||
894 | /** | |
895 | * nfs_file_direct_read - file direct read operation for NFS files | |
896 | * @iocb: target I/O control block | |
027445c3 BP |
897 | * @iov: vector of user buffers into which to read data |
898 | * @nr_segs: size of iov vector | |
88467055 | 899 | * @pos: byte offset in file where reading starts |
1da177e4 LT |
900 | * |
901 | * We use this function for direct reads instead of calling | |
902 | * generic_file_aio_read() in order to avoid gfar's check to see if | |
903 | * the request starts before the end of the file. For that check | |
904 | * to work, we must generate a GETATTR before each direct read, and | |
905 | * even then there is a window between the GETATTR and the subsequent | |
88467055 | 906 | * READ where the file size could change. Our preference is simply |
1da177e4 LT |
907 | * to do all reads the application wants, and the server will take |
908 | * care of managing the end of file boundary. | |
88467055 | 909 | * |
1da177e4 LT |
910 | * This function also eliminates unnecessarily updating the file's |
911 | * atime locally, as the NFS server sets the file's atime, and this | |
912 | * client must read the updated atime from the server back into its | |
913 | * cache. | |
914 | */ | |
027445c3 | 915 | ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, |
a564b8f0 | 916 | unsigned long nr_segs, loff_t pos, bool uio) |
1da177e4 LT |
917 | { |
918 | ssize_t retval = -EINVAL; | |
1da177e4 | 919 | struct file *file = iocb->ki_filp; |
1da177e4 | 920 | struct address_space *mapping = file->f_mapping; |
c216fd70 CL |
921 | size_t count; |
922 | ||
923 | count = iov_length(iov, nr_segs); | |
924 | nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); | |
1da177e4 | 925 | |
6da24bc9 | 926 | dfprintk(FILE, "NFS: direct read(%s/%s, %zd@%Ld)\n", |
01cce933 JJS |
927 | file->f_path.dentry->d_parent->d_name.name, |
928 | file->f_path.dentry->d_name.name, | |
c216fd70 | 929 | count, (long long) pos); |
1da177e4 | 930 | |
1da177e4 LT |
931 | retval = 0; |
932 | if (!count) | |
933 | goto out; | |
934 | ||
29884df0 TM |
935 | retval = nfs_sync_mapping(mapping); |
936 | if (retval) | |
937 | goto out; | |
1da177e4 | 938 | |
7ec10f26 KK |
939 | task_io_account_read(count); |
940 | ||
a564b8f0 | 941 | retval = nfs_direct_read(iocb, iov, nr_segs, pos, uio); |
1da177e4 | 942 | if (retval > 0) |
0cdd80d0 | 943 | iocb->ki_pos = pos + retval; |
1da177e4 LT |
944 | |
945 | out: | |
946 | return retval; | |
947 | } | |
948 | ||
949 | /** | |
950 | * nfs_file_direct_write - file direct write operation for NFS files | |
951 | * @iocb: target I/O control block | |
027445c3 BP |
952 | * @iov: vector of user buffers from which to write data |
953 | * @nr_segs: size of iov vector | |
88467055 | 954 | * @pos: byte offset in file where writing starts |
1da177e4 LT |
955 | * |
956 | * We use this function for direct writes instead of calling | |
957 | * generic_file_aio_write() in order to avoid taking the inode | |
958 | * semaphore and updating the i_size. The NFS server will set | |
959 | * the new i_size and this client must read the updated size | |
960 | * back into its cache. We let the server do generic write | |
961 | * parameter checking and report problems. | |
962 | * | |
1da177e4 LT |
963 | * We eliminate local atime updates, see direct read above. |
964 | * | |
965 | * We avoid unnecessary page cache invalidations for normal cached | |
966 | * readers of this file. | |
967 | * | |
968 | * Note that O_APPEND is not supported for NFS direct writes, as there | |
969 | * is no atomic O_APPEND write facility in the NFS protocol. | |
970 | */ | |
027445c3 | 971 | ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov, |
a564b8f0 | 972 | unsigned long nr_segs, loff_t pos, bool uio) |
1da177e4 | 973 | { |
070ea602 | 974 | ssize_t retval = -EINVAL; |
1da177e4 | 975 | struct file *file = iocb->ki_filp; |
1da177e4 | 976 | struct address_space *mapping = file->f_mapping; |
c216fd70 | 977 | size_t count; |
1da177e4 | 978 | |
c216fd70 CL |
979 | count = iov_length(iov, nr_segs); |
980 | nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count); | |
981 | ||
6da24bc9 | 982 | dfprintk(FILE, "NFS: direct write(%s/%s, %zd@%Ld)\n", |
01cce933 JJS |
983 | file->f_path.dentry->d_parent->d_name.name, |
984 | file->f_path.dentry->d_name.name, | |
c216fd70 | 985 | count, (long long) pos); |
027445c3 | 986 | |
ce1a8e67 CL |
987 | retval = generic_write_checks(file, &pos, &count, 0); |
988 | if (retval) | |
1da177e4 | 989 | goto out; |
ce1a8e67 CL |
990 | |
991 | retval = -EINVAL; | |
992 | if ((ssize_t) count < 0) | |
1da177e4 | 993 | goto out; |
1da177e4 LT |
994 | retval = 0; |
995 | if (!count) | |
996 | goto out; | |
ce1a8e67 | 997 | |
29884df0 TM |
998 | retval = nfs_sync_mapping(mapping); |
999 | if (retval) | |
1000 | goto out; | |
1da177e4 | 1001 | |
7ec10f26 KK |
1002 | task_io_account_write(count); |
1003 | ||
a564b8f0 | 1004 | retval = nfs_direct_write(iocb, iov, nr_segs, pos, count, uio); |
1763da12 FI |
1005 | if (retval > 0) { |
1006 | struct inode *inode = mapping->host; | |
9eafa8cc | 1007 | |
ce1a8e67 | 1008 | iocb->ki_pos = pos + retval; |
1763da12 FI |
1009 | spin_lock(&inode->i_lock); |
1010 | if (i_size_read(inode) < iocb->ki_pos) | |
1011 | i_size_write(inode, iocb->ki_pos); | |
1012 | spin_unlock(&inode->i_lock); | |
1013 | } | |
1da177e4 LT |
1014 | out: |
1015 | return retval; | |
1016 | } | |
1017 | ||
88467055 CL |
1018 | /** |
1019 | * nfs_init_directcache - create a slab cache for nfs_direct_req structures | |
1020 | * | |
1021 | */ | |
f7b422b1 | 1022 | int __init nfs_init_directcache(void) |
1da177e4 LT |
1023 | { |
1024 | nfs_direct_cachep = kmem_cache_create("nfs_direct_cache", | |
1025 | sizeof(struct nfs_direct_req), | |
fffb60f9 PJ |
1026 | 0, (SLAB_RECLAIM_ACCOUNT| |
1027 | SLAB_MEM_SPREAD), | |
20c2df83 | 1028 | NULL); |
1da177e4 LT |
1029 | if (nfs_direct_cachep == NULL) |
1030 | return -ENOMEM; | |
1031 | ||
1032 | return 0; | |
1033 | } | |
1034 | ||
88467055 | 1035 | /** |
f7b422b1 | 1036 | * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures |
88467055 CL |
1037 | * |
1038 | */ | |
266bee88 | 1039 | void nfs_destroy_directcache(void) |
1da177e4 | 1040 | { |
1a1d92c1 | 1041 | kmem_cache_destroy(nfs_direct_cachep); |
1da177e4 | 1042 | } |