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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
106
107 req = nfs_page_alloc();
108 if (req == NULL)
109 return ERR_PTR(-ENOMEM);
110
111
112 req->wb_lock_context = nfs_get_lock_context(ctx);
113 if (req->wb_lock_context == NULL) {
114 nfs_page_free(req);
115 return ERR_PTR(-ENOMEM);
116 }
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120
121 req->wb_page = page;
122 req->wb_index = page_file_index(page);
123 page_cache_get(page);
124 req->wb_offset = offset;
125 req->wb_pgbase = offset;
126 req->wb_bytes = count;
127 req->wb_context = get_nfs_open_context(ctx);
128 kref_init(&req->wb_kref);
129 return req;
130}
131
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135
136void nfs_unlock_request(struct nfs_page *req)
137{
138 if (!NFS_WBACK_BUSY(req)) {
139 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
140 BUG();
141 }
142 smp_mb__before_clear_bit();
143 clear_bit(PG_BUSY, &req->wb_flags);
144 smp_mb__after_clear_bit();
145 wake_up_bit(&req->wb_flags, PG_BUSY);
146}
147
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151
152void nfs_unlock_and_release_request(struct nfs_page *req)
153{
154 nfs_unlock_request(req);
155 nfs_release_request(req);
156}
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164
165static void nfs_clear_request(struct nfs_page *req)
166{
167 struct page *page = req->wb_page;
168 struct nfs_open_context *ctx = req->wb_context;
169 struct nfs_lock_context *l_ctx = req->wb_lock_context;
170
171 if (page != NULL) {
172 page_cache_release(page);
173 req->wb_page = NULL;
174 }
175 if (l_ctx != NULL) {
176 nfs_put_lock_context(l_ctx);
177 req->wb_lock_context = NULL;
178 }
179 if (ctx != NULL) {
180 put_nfs_open_context(ctx);
181 req->wb_context = NULL;
182 }
183}
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191
192static void nfs_free_request(struct kref *kref)
193{
194 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
195
196
197 nfs_clear_request(req);
198 nfs_page_free(req);
199}
200
201void nfs_release_request(struct nfs_page *req)
202{
203 kref_put(&req->wb_kref, nfs_free_request);
204}
205
206static int nfs_wait_bit_uninterruptible(void *word)
207{
208 io_schedule();
209 return 0;
210}
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218
219int
220nfs_wait_on_request(struct nfs_page *req)
221{
222 return wait_on_bit(&req->wb_flags, PG_BUSY,
223 nfs_wait_bit_uninterruptible,
224 TASK_UNINTERRUPTIBLE);
225}
226
227bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
228{
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235
236 if (desc->pg_bsize < PAGE_SIZE)
237 return 0;
238
239 return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
240}
241EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
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250
251void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
252 struct inode *inode,
253 const struct nfs_pageio_ops *pg_ops,
254 const struct nfs_pgio_completion_ops *compl_ops,
255 size_t bsize,
256 int io_flags)
257{
258 INIT_LIST_HEAD(&desc->pg_list);
259 desc->pg_bytes_written = 0;
260 desc->pg_count = 0;
261 desc->pg_bsize = bsize;
262 desc->pg_base = 0;
263 desc->pg_moreio = 0;
264 desc->pg_recoalesce = 0;
265 desc->pg_inode = inode;
266 desc->pg_ops = pg_ops;
267 desc->pg_completion_ops = compl_ops;
268 desc->pg_ioflags = io_flags;
269 desc->pg_error = 0;
270 desc->pg_lseg = NULL;
271 desc->pg_dreq = NULL;
272 desc->pg_layout_private = NULL;
273}
274EXPORT_SYMBOL_GPL(nfs_pageio_init);
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286
287static bool nfs_can_coalesce_requests(struct nfs_page *prev,
288 struct nfs_page *req,
289 struct nfs_pageio_descriptor *pgio)
290{
291 if (req->wb_context->cred != prev->wb_context->cred)
292 return false;
293 if (req->wb_lock_context->lockowner != prev->wb_lock_context->lockowner)
294 return false;
295 if (req->wb_context->state != prev->wb_context->state)
296 return false;
297 if (req->wb_pgbase != 0)
298 return false;
299 if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
300 return false;
301 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
302 return false;
303 return pgio->pg_ops->pg_test(pgio, prev, req);
304}
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313
314static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
315 struct nfs_page *req)
316{
317 if (desc->pg_count != 0) {
318 struct nfs_page *prev;
319
320 prev = nfs_list_entry(desc->pg_list.prev);
321 if (!nfs_can_coalesce_requests(prev, req, desc))
322 return 0;
323 } else {
324 if (desc->pg_ops->pg_init)
325 desc->pg_ops->pg_init(desc, req);
326 desc->pg_base = req->wb_pgbase;
327 }
328 nfs_list_remove_request(req);
329 nfs_list_add_request(req, &desc->pg_list);
330 desc->pg_count += req->wb_bytes;
331 return 1;
332}
333
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336
337static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
338{
339 if (!list_empty(&desc->pg_list)) {
340 int error = desc->pg_ops->pg_doio(desc);
341 if (error < 0)
342 desc->pg_error = error;
343 else
344 desc->pg_bytes_written += desc->pg_count;
345 }
346 if (list_empty(&desc->pg_list)) {
347 desc->pg_count = 0;
348 desc->pg_base = 0;
349 }
350}
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359
360static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
361 struct nfs_page *req)
362{
363 while (!nfs_pageio_do_add_request(desc, req)) {
364 desc->pg_moreio = 1;
365 nfs_pageio_doio(desc);
366 if (desc->pg_error < 0)
367 return 0;
368 desc->pg_moreio = 0;
369 if (desc->pg_recoalesce)
370 return 0;
371 }
372 return 1;
373}
374
375static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
376{
377 LIST_HEAD(head);
378
379 do {
380 list_splice_init(&desc->pg_list, &head);
381 desc->pg_bytes_written -= desc->pg_count;
382 desc->pg_count = 0;
383 desc->pg_base = 0;
384 desc->pg_recoalesce = 0;
385
386 while (!list_empty(&head)) {
387 struct nfs_page *req;
388
389 req = list_first_entry(&head, struct nfs_page, wb_list);
390 nfs_list_remove_request(req);
391 if (__nfs_pageio_add_request(desc, req))
392 continue;
393 if (desc->pg_error < 0)
394 return 0;
395 break;
396 }
397 } while (desc->pg_recoalesce);
398 return 1;
399}
400
401int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
402 struct nfs_page *req)
403{
404 int ret;
405
406 do {
407 ret = __nfs_pageio_add_request(desc, req);
408 if (ret)
409 break;
410 if (desc->pg_error < 0)
411 break;
412 ret = nfs_do_recoalesce(desc);
413 } while (ret);
414 return ret;
415}
416EXPORT_SYMBOL_GPL(nfs_pageio_add_request);
417
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421
422void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
423{
424 for (;;) {
425 nfs_pageio_doio(desc);
426 if (!desc->pg_recoalesce)
427 break;
428 if (!nfs_do_recoalesce(desc))
429 break;
430 }
431}
432EXPORT_SYMBOL_GPL(nfs_pageio_complete);
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444
445void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
446{
447 if (!list_empty(&desc->pg_list)) {
448 struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev);
449 if (index != prev->wb_index + 1)
450 nfs_pageio_complete(desc);
451 }
452}
453
454int __init nfs_init_nfspagecache(void)
455{
456 nfs_page_cachep = kmem_cache_create("nfs_page",
457 sizeof(struct nfs_page),
458 0, SLAB_HWCACHE_ALIGN,
459 NULL);
460 if (nfs_page_cachep == NULL)
461 return -ENOMEM;
462
463 return 0;
464}
465
466void nfs_destroy_nfspagecache(void)
467{
468 kmem_cache_destroy(nfs_page_cachep);
469}
470
471