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12#include <linux/slab.h>
13#include <linux/file.h>
14#include <linux/sched.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/nfs.h>
17#include <linux/nfs3.h>
18#include <linux/nfs4.h>
19#include <linux/nfs_page.h>
20#include <linux/nfs_fs.h>
21#include <linux/nfs_mount.h>
22#include <linux/export.h>
23
24#include "internal.h"
25#include "pnfs.h"
26
27static struct kmem_cache *nfs_page_cachep;
28
29bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
30{
31 p->npages = pagecount;
32 if (pagecount <= ARRAY_SIZE(p->page_array))
33 p->pagevec = p->page_array;
34 else {
35 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
36 if (!p->pagevec)
37 p->npages = 0;
38 }
39 return p->pagevec != NULL;
40}
41
42void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
43 struct nfs_pgio_header *hdr,
44 void (*release)(struct nfs_pgio_header *hdr))
45{
46 hdr->req = nfs_list_entry(desc->pg_list.next);
47 hdr->inode = desc->pg_inode;
48 hdr->cred = hdr->req->wb_context->cred;
49 hdr->io_start = req_offset(hdr->req);
50 hdr->good_bytes = desc->pg_count;
51 hdr->dreq = desc->pg_dreq;
52 hdr->layout_private = desc->pg_layout_private;
53 hdr->release = release;
54 hdr->completion_ops = desc->pg_completion_ops;
55 if (hdr->completion_ops->init_hdr)
56 hdr->completion_ops->init_hdr(hdr);
57}
58EXPORT_SYMBOL_GPL(nfs_pgheader_init);
59
60void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
61{
62 spin_lock(&hdr->lock);
63 if (pos < hdr->io_start + hdr->good_bytes) {
64 set_bit(NFS_IOHDR_ERROR, &hdr->flags);
65 clear_bit(NFS_IOHDR_EOF, &hdr->flags);
66 hdr->good_bytes = pos - hdr->io_start;
67 hdr->error = error;
68 }
69 spin_unlock(&hdr->lock);
70}
71
72static inline struct nfs_page *
73nfs_page_alloc(void)
74{
75 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
76 if (p)
77 INIT_LIST_HEAD(&p->wb_list);
78 return p;
79}
80
81static inline void
82nfs_page_free(struct nfs_page *p)
83{
84 kmem_cache_free(nfs_page_cachep, p);
85}
86
87static void
88nfs_iocounter_inc(struct nfs_io_counter *c)
89{
90 atomic_inc(&c->io_count);
91}
92
93static void
94nfs_iocounter_dec(struct nfs_io_counter *c)
95{
96 if (atomic_dec_and_test(&c->io_count)) {
97 clear_bit(NFS_IO_INPROGRESS, &c->flags);
98 smp_mb__after_clear_bit();
99 wake_up_bit(&c->flags, NFS_IO_INPROGRESS);
100 }
101}
102
103static int
104__nfs_iocounter_wait(struct nfs_io_counter *c)
105{
106 wait_queue_head_t *wq = bit_waitqueue(&c->flags, NFS_IO_INPROGRESS);
107 DEFINE_WAIT_BIT(q, &c->flags, NFS_IO_INPROGRESS);
108 int ret = 0;
109
110 do {
111 prepare_to_wait(wq, &q.wait, TASK_KILLABLE);
112 set_bit(NFS_IO_INPROGRESS, &c->flags);
113 if (atomic_read(&c->io_count) == 0)
114 break;
115 ret = nfs_wait_bit_killable(&c->flags);
116 } while (atomic_read(&c->io_count) != 0);
117 finish_wait(wq, &q.wait);
118 return ret;
119}
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127
128int
129nfs_iocounter_wait(struct nfs_io_counter *c)
130{
131 if (atomic_read(&c->io_count) == 0)
132 return 0;
133 return __nfs_iocounter_wait(c);
134}
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147
148struct nfs_page *
149nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
150 struct page *page,
151 unsigned int offset, unsigned int count)
152{
153 struct nfs_page *req;
154 struct nfs_lock_context *l_ctx;
155
156 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
157 return ERR_PTR(-EBADF);
158
159 req = nfs_page_alloc();
160 if (req == NULL)
161 return ERR_PTR(-ENOMEM);
162
163
164 l_ctx = nfs_get_lock_context(ctx);
165 if (IS_ERR(l_ctx)) {
166 nfs_page_free(req);
167 return ERR_CAST(l_ctx);
168 }
169 req->wb_lock_context = l_ctx;
170 nfs_iocounter_inc(&l_ctx->io_count);
171
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174
175 req->wb_page = page;
176 req->wb_index = page_file_index(page);
177 page_cache_get(page);
178 req->wb_offset = offset;
179 req->wb_pgbase = offset;
180 req->wb_bytes = count;
181 req->wb_context = get_nfs_open_context(ctx);
182 kref_init(&req->wb_kref);
183 return req;
184}
185
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189
190void nfs_unlock_request(struct nfs_page *req)
191{
192 if (!NFS_WBACK_BUSY(req)) {
193 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
194 BUG();
195 }
196 smp_mb__before_clear_bit();
197 clear_bit(PG_BUSY, &req->wb_flags);
198 smp_mb__after_clear_bit();
199 wake_up_bit(&req->wb_flags, PG_BUSY);
200}
201
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205
206void nfs_unlock_and_release_request(struct nfs_page *req)
207{
208 nfs_unlock_request(req);
209 nfs_release_request(req);
210}
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218
219static void nfs_clear_request(struct nfs_page *req)
220{
221 struct page *page = req->wb_page;
222 struct nfs_open_context *ctx = req->wb_context;
223 struct nfs_lock_context *l_ctx = req->wb_lock_context;
224
225 if (page != NULL) {
226 page_cache_release(page);
227 req->wb_page = NULL;
228 }
229 if (l_ctx != NULL) {
230 nfs_iocounter_dec(&l_ctx->io_count);
231 nfs_put_lock_context(l_ctx);
232 req->wb_lock_context = NULL;
233 }
234 if (ctx != NULL) {
235 put_nfs_open_context(ctx);
236 req->wb_context = NULL;
237 }
238}
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246
247static void nfs_free_request(struct kref *kref)
248{
249 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
250
251
252 nfs_clear_request(req);
253 nfs_page_free(req);
254}
255
256void nfs_release_request(struct nfs_page *req)
257{
258 kref_put(&req->wb_kref, nfs_free_request);
259}
260
261static int nfs_wait_bit_uninterruptible(void *word)
262{
263 io_schedule();
264 return 0;
265}
266
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273
274int
275nfs_wait_on_request(struct nfs_page *req)
276{
277 return wait_on_bit(&req->wb_flags, PG_BUSY,
278 nfs_wait_bit_uninterruptible,
279 TASK_UNINTERRUPTIBLE);
280}
281
282bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
283{
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290
291 if (desc->pg_bsize < PAGE_SIZE)
292 return 0;
293
294 return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
295}
296EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
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306void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
307 struct inode *inode,
308 const struct nfs_pageio_ops *pg_ops,
309 const struct nfs_pgio_completion_ops *compl_ops,
310 size_t bsize,
311 int io_flags)
312{
313 INIT_LIST_HEAD(&desc->pg_list);
314 desc->pg_bytes_written = 0;
315 desc->pg_count = 0;
316 desc->pg_bsize = bsize;
317 desc->pg_base = 0;
318 desc->pg_moreio = 0;
319 desc->pg_recoalesce = 0;
320 desc->pg_inode = inode;
321 desc->pg_ops = pg_ops;
322 desc->pg_completion_ops = compl_ops;
323 desc->pg_ioflags = io_flags;
324 desc->pg_error = 0;
325 desc->pg_lseg = NULL;
326 desc->pg_dreq = NULL;
327 desc->pg_layout_private = NULL;
328}
329EXPORT_SYMBOL_GPL(nfs_pageio_init);
330
331static bool nfs_match_open_context(const struct nfs_open_context *ctx1,
332 const struct nfs_open_context *ctx2)
333{
334 return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state;
335}
336
337static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
338 const struct nfs_lock_context *l2)
339{
340 return l1->lockowner.l_owner == l2->lockowner.l_owner
341 && l1->lockowner.l_pid == l2->lockowner.l_pid;
342}
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354
355static bool nfs_can_coalesce_requests(struct nfs_page *prev,
356 struct nfs_page *req,
357 struct nfs_pageio_descriptor *pgio)
358{
359 if (!nfs_match_open_context(req->wb_context, prev->wb_context))
360 return false;
361 if (req->wb_context->dentry->d_inode->i_flock != NULL &&
362 !nfs_match_lock_context(req->wb_lock_context, prev->wb_lock_context))
363 return false;
364 if (req->wb_pgbase != 0)
365 return false;
366 if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
367 return false;
368 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
369 return false;
370 return pgio->pg_ops->pg_test(pgio, prev, req);
371}
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380
381static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
382 struct nfs_page *req)
383{
384 if (desc->pg_count != 0) {
385 struct nfs_page *prev;
386
387 prev = nfs_list_entry(desc->pg_list.prev);
388 if (!nfs_can_coalesce_requests(prev, req, desc))
389 return 0;
390 } else {
391 if (desc->pg_ops->pg_init)
392 desc->pg_ops->pg_init(desc, req);
393 desc->pg_base = req->wb_pgbase;
394 }
395 nfs_list_remove_request(req);
396 nfs_list_add_request(req, &desc->pg_list);
397 desc->pg_count += req->wb_bytes;
398 return 1;
399}
400
401
402
403
404static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
405{
406 if (!list_empty(&desc->pg_list)) {
407 int error = desc->pg_ops->pg_doio(desc);
408 if (error < 0)
409 desc->pg_error = error;
410 else
411 desc->pg_bytes_written += desc->pg_count;
412 }
413 if (list_empty(&desc->pg_list)) {
414 desc->pg_count = 0;
415 desc->pg_base = 0;
416 }
417}
418
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425
426
427static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
428 struct nfs_page *req)
429{
430 while (!nfs_pageio_do_add_request(desc, req)) {
431 desc->pg_moreio = 1;
432 nfs_pageio_doio(desc);
433 if (desc->pg_error < 0)
434 return 0;
435 desc->pg_moreio = 0;
436 if (desc->pg_recoalesce)
437 return 0;
438 }
439 return 1;
440}
441
442static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
443{
444 LIST_HEAD(head);
445
446 do {
447 list_splice_init(&desc->pg_list, &head);
448 desc->pg_bytes_written -= desc->pg_count;
449 desc->pg_count = 0;
450 desc->pg_base = 0;
451 desc->pg_recoalesce = 0;
452
453 while (!list_empty(&head)) {
454 struct nfs_page *req;
455
456 req = list_first_entry(&head, struct nfs_page, wb_list);
457 nfs_list_remove_request(req);
458 if (__nfs_pageio_add_request(desc, req))
459 continue;
460 if (desc->pg_error < 0)
461 return 0;
462 break;
463 }
464 } while (desc->pg_recoalesce);
465 return 1;
466}
467
468int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
469 struct nfs_page *req)
470{
471 int ret;
472
473 do {
474 ret = __nfs_pageio_add_request(desc, req);
475 if (ret)
476 break;
477 if (desc->pg_error < 0)
478 break;
479 ret = nfs_do_recoalesce(desc);
480 } while (ret);
481 return ret;
482}
483EXPORT_SYMBOL_GPL(nfs_pageio_add_request);
484
485
486
487
488
489void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
490{
491 for (;;) {
492 nfs_pageio_doio(desc);
493 if (!desc->pg_recoalesce)
494 break;
495 if (!nfs_do_recoalesce(desc))
496 break;
497 }
498}
499EXPORT_SYMBOL_GPL(nfs_pageio_complete);
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510
511
512void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
513{
514 if (!list_empty(&desc->pg_list)) {
515 struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev);
516 if (index != prev->wb_index + 1)
517 nfs_pageio_complete(desc);
518 }
519}
520
521int __init nfs_init_nfspagecache(void)
522{
523 nfs_page_cachep = kmem_cache_create("nfs_page",
524 sizeof(struct nfs_page),
525 0, SLAB_HWCACHE_ALIGN,
526 NULL);
527 if (nfs_page_cachep == NULL)
528 return -ENOMEM;
529
530 return 0;
531}
532
533void nfs_destroy_nfspagecache(void)
534{
535 kmem_cache_destroy(nfs_page_cachep);
536}
537
538