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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}
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98
99struct nfs_page *
100nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
101 struct page *page,
102 unsigned int offset, unsigned int count)
103{
104 struct nfs_page *req;
105 struct nfs_lock_context *l_ctx;
106
107
108 req = nfs_page_alloc();
109 if (req == NULL)
110 return ERR_PTR(-ENOMEM);
111
112
113 l_ctx = nfs_get_lock_context(ctx);
114 if (IS_ERR(l_ctx)) {
115 nfs_page_free(req);
116 return ERR_CAST(l_ctx);
117 }
118 req->wb_lock_context = l_ctx;
119
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122
123 req->wb_page = page;
124 req->wb_index = page_file_index(page);
125 page_cache_get(page);
126 req->wb_offset = offset;
127 req->wb_pgbase = offset;
128 req->wb_bytes = count;
129 req->wb_context = get_nfs_open_context(ctx);
130 kref_init(&req->wb_kref);
131 return req;
132}
133
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136
137
138void nfs_unlock_request(struct nfs_page *req)
139{
140 if (!NFS_WBACK_BUSY(req)) {
141 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
142 BUG();
143 }
144 smp_mb__before_clear_bit();
145 clear_bit(PG_BUSY, &req->wb_flags);
146 smp_mb__after_clear_bit();
147 wake_up_bit(&req->wb_flags, PG_BUSY);
148}
149
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153
154void nfs_unlock_and_release_request(struct nfs_page *req)
155{
156 nfs_unlock_request(req);
157 nfs_release_request(req);
158}
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166
167static void nfs_clear_request(struct nfs_page *req)
168{
169 struct page *page = req->wb_page;
170 struct nfs_open_context *ctx = req->wb_context;
171 struct nfs_lock_context *l_ctx = req->wb_lock_context;
172
173 if (page != NULL) {
174 page_cache_release(page);
175 req->wb_page = NULL;
176 }
177 if (l_ctx != NULL) {
178 nfs_put_lock_context(l_ctx);
179 req->wb_lock_context = NULL;
180 }
181 if (ctx != NULL) {
182 put_nfs_open_context(ctx);
183 req->wb_context = NULL;
184 }
185}
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193
194static void nfs_free_request(struct kref *kref)
195{
196 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
197
198
199 nfs_clear_request(req);
200 nfs_page_free(req);
201}
202
203void nfs_release_request(struct nfs_page *req)
204{
205 kref_put(&req->wb_kref, nfs_free_request);
206}
207
208static int nfs_wait_bit_uninterruptible(void *word)
209{
210 io_schedule();
211 return 0;
212}
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220
221int
222nfs_wait_on_request(struct nfs_page *req)
223{
224 return wait_on_bit(&req->wb_flags, PG_BUSY,
225 nfs_wait_bit_uninterruptible,
226 TASK_UNINTERRUPTIBLE);
227}
228
229bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
230{
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237
238 if (desc->pg_bsize < PAGE_SIZE)
239 return 0;
240
241 return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
242}
243EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
244
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252
253void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
254 struct inode *inode,
255 const struct nfs_pageio_ops *pg_ops,
256 const struct nfs_pgio_completion_ops *compl_ops,
257 size_t bsize,
258 int io_flags)
259{
260 INIT_LIST_HEAD(&desc->pg_list);
261 desc->pg_bytes_written = 0;
262 desc->pg_count = 0;
263 desc->pg_bsize = bsize;
264 desc->pg_base = 0;
265 desc->pg_moreio = 0;
266 desc->pg_recoalesce = 0;
267 desc->pg_inode = inode;
268 desc->pg_ops = pg_ops;
269 desc->pg_completion_ops = compl_ops;
270 desc->pg_ioflags = io_flags;
271 desc->pg_error = 0;
272 desc->pg_lseg = NULL;
273 desc->pg_dreq = NULL;
274 desc->pg_layout_private = NULL;
275}
276EXPORT_SYMBOL_GPL(nfs_pageio_init);
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288
289static bool nfs_can_coalesce_requests(struct nfs_page *prev,
290 struct nfs_page *req,
291 struct nfs_pageio_descriptor *pgio)
292{
293 if (req->wb_context->cred != prev->wb_context->cred)
294 return false;
295 if (req->wb_lock_context->lockowner.l_owner != prev->wb_lock_context->lockowner.l_owner)
296 return false;
297 if (req->wb_lock_context->lockowner.l_pid != prev->wb_lock_context->lockowner.l_pid)
298 return false;
299 if (req->wb_context->state != prev->wb_context->state)
300 return false;
301 if (req->wb_pgbase != 0)
302 return false;
303 if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
304 return false;
305 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
306 return false;
307 return pgio->pg_ops->pg_test(pgio, prev, req);
308}
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317
318static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
319 struct nfs_page *req)
320{
321 if (desc->pg_count != 0) {
322 struct nfs_page *prev;
323
324 prev = nfs_list_entry(desc->pg_list.prev);
325 if (!nfs_can_coalesce_requests(prev, req, desc))
326 return 0;
327 } else {
328 if (desc->pg_ops->pg_init)
329 desc->pg_ops->pg_init(desc, req);
330 desc->pg_base = req->wb_pgbase;
331 }
332 nfs_list_remove_request(req);
333 nfs_list_add_request(req, &desc->pg_list);
334 desc->pg_count += req->wb_bytes;
335 return 1;
336}
337
338
339
340
341static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
342{
343 if (!list_empty(&desc->pg_list)) {
344 int error = desc->pg_ops->pg_doio(desc);
345 if (error < 0)
346 desc->pg_error = error;
347 else
348 desc->pg_bytes_written += desc->pg_count;
349 }
350 if (list_empty(&desc->pg_list)) {
351 desc->pg_count = 0;
352 desc->pg_base = 0;
353 }
354}
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363
364static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
365 struct nfs_page *req)
366{
367 while (!nfs_pageio_do_add_request(desc, req)) {
368 desc->pg_moreio = 1;
369 nfs_pageio_doio(desc);
370 if (desc->pg_error < 0)
371 return 0;
372 desc->pg_moreio = 0;
373 if (desc->pg_recoalesce)
374 return 0;
375 }
376 return 1;
377}
378
379static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
380{
381 LIST_HEAD(head);
382
383 do {
384 list_splice_init(&desc->pg_list, &head);
385 desc->pg_bytes_written -= desc->pg_count;
386 desc->pg_count = 0;
387 desc->pg_base = 0;
388 desc->pg_recoalesce = 0;
389
390 while (!list_empty(&head)) {
391 struct nfs_page *req;
392
393 req = list_first_entry(&head, struct nfs_page, wb_list);
394 nfs_list_remove_request(req);
395 if (__nfs_pageio_add_request(desc, req))
396 continue;
397 if (desc->pg_error < 0)
398 return 0;
399 break;
400 }
401 } while (desc->pg_recoalesce);
402 return 1;
403}
404
405int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
406 struct nfs_page *req)
407{
408 int ret;
409
410 do {
411 ret = __nfs_pageio_add_request(desc, req);
412 if (ret)
413 break;
414 if (desc->pg_error < 0)
415 break;
416 ret = nfs_do_recoalesce(desc);
417 } while (ret);
418 return ret;
419}
420EXPORT_SYMBOL_GPL(nfs_pageio_add_request);
421
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425
426void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
427{
428 for (;;) {
429 nfs_pageio_doio(desc);
430 if (!desc->pg_recoalesce)
431 break;
432 if (!nfs_do_recoalesce(desc))
433 break;
434 }
435}
436EXPORT_SYMBOL_GPL(nfs_pageio_complete);
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447
448
449void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
450{
451 if (!list_empty(&desc->pg_list)) {
452 struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev);
453 if (index != prev->wb_index + 1)
454 nfs_pageio_complete(desc);
455 }
456}
457
458int __init nfs_init_nfspagecache(void)
459{
460 nfs_page_cachep = kmem_cache_create("nfs_page",
461 sizeof(struct nfs_page),
462 0, SLAB_HWCACHE_ALIGN,
463 NULL);
464 if (nfs_page_cachep == NULL)
465 return -ENOMEM;
466
467 return 0;
468}
469
470void nfs_destroy_nfspagecache(void)
471{
472 kmem_cache_destroy(nfs_page_cachep);
473}
474
475