Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/net/sunrpc/xdr.c | |
4 | * | |
5 | * Generic XDR support. | |
6 | * | |
7 | * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> | |
8 | */ | |
9 | ||
a246b010 | 10 | #include <linux/module.h> |
5a0e3ad6 | 11 | #include <linux/slab.h> |
1da177e4 | 12 | #include <linux/types.h> |
1da177e4 LT |
13 | #include <linux/string.h> |
14 | #include <linux/kernel.h> | |
15 | #include <linux/pagemap.h> | |
16 | #include <linux/errno.h> | |
1da177e4 LT |
17 | #include <linux/sunrpc/xdr.h> |
18 | #include <linux/sunrpc/msg_prot.h> | |
9d96acbc | 19 | #include <linux/bvec.h> |
5582863f | 20 | #include <trace/events/sunrpc.h> |
1da177e4 | 21 | |
e6ac0acc AS |
22 | static void _copy_to_pages(struct page **, size_t, const char *, size_t); |
23 | ||
24 | ||
1da177e4 LT |
25 | /* |
26 | * XDR functions for basic NFS types | |
27 | */ | |
d8ed029d AD |
28 | __be32 * |
29 | xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj) | |
1da177e4 LT |
30 | { |
31 | unsigned int quadlen = XDR_QUADLEN(obj->len); | |
32 | ||
33 | p[quadlen] = 0; /* zero trailing bytes */ | |
9f162d2a | 34 | *p++ = cpu_to_be32(obj->len); |
1da177e4 LT |
35 | memcpy(p, obj->data, obj->len); |
36 | return p + XDR_QUADLEN(obj->len); | |
37 | } | |
468039ee | 38 | EXPORT_SYMBOL_GPL(xdr_encode_netobj); |
1da177e4 | 39 | |
d8ed029d AD |
40 | __be32 * |
41 | xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj) | |
1da177e4 LT |
42 | { |
43 | unsigned int len; | |
44 | ||
98866b5a | 45 | if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ) |
1da177e4 LT |
46 | return NULL; |
47 | obj->len = len; | |
48 | obj->data = (u8 *) p; | |
49 | return p + XDR_QUADLEN(len); | |
50 | } | |
468039ee | 51 | EXPORT_SYMBOL_GPL(xdr_decode_netobj); |
1da177e4 LT |
52 | |
53 | /** | |
54 | * xdr_encode_opaque_fixed - Encode fixed length opaque data | |
4dc3b16b PP |
55 | * @p: pointer to current position in XDR buffer. |
56 | * @ptr: pointer to data to encode (or NULL) | |
57 | * @nbytes: size of data. | |
1da177e4 LT |
58 | * |
59 | * Copy the array of data of length nbytes at ptr to the XDR buffer | |
60 | * at position p, then align to the next 32-bit boundary by padding | |
61 | * with zero bytes (see RFC1832). | |
62 | * Note: if ptr is NULL, only the padding is performed. | |
63 | * | |
64 | * Returns the updated current XDR buffer position | |
65 | * | |
66 | */ | |
d8ed029d | 67 | __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 LT |
68 | { |
69 | if (likely(nbytes != 0)) { | |
70 | unsigned int quadlen = XDR_QUADLEN(nbytes); | |
71 | unsigned int padding = (quadlen << 2) - nbytes; | |
72 | ||
73 | if (ptr != NULL) | |
74 | memcpy(p, ptr, nbytes); | |
75 | if (padding != 0) | |
76 | memset((char *)p + nbytes, 0, padding); | |
77 | p += quadlen; | |
78 | } | |
79 | return p; | |
80 | } | |
468039ee | 81 | EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed); |
1da177e4 LT |
82 | |
83 | /** | |
84 | * xdr_encode_opaque - Encode variable length opaque data | |
4dc3b16b PP |
85 | * @p: pointer to current position in XDR buffer. |
86 | * @ptr: pointer to data to encode (or NULL) | |
87 | * @nbytes: size of data. | |
1da177e4 LT |
88 | * |
89 | * Returns the updated current XDR buffer position | |
90 | */ | |
d8ed029d | 91 | __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 | 92 | { |
9f162d2a | 93 | *p++ = cpu_to_be32(nbytes); |
1da177e4 LT |
94 | return xdr_encode_opaque_fixed(p, ptr, nbytes); |
95 | } | |
468039ee | 96 | EXPORT_SYMBOL_GPL(xdr_encode_opaque); |
1da177e4 | 97 | |
d8ed029d AD |
98 | __be32 * |
99 | xdr_encode_string(__be32 *p, const char *string) | |
1da177e4 LT |
100 | { |
101 | return xdr_encode_array(p, string, strlen(string)); | |
102 | } | |
468039ee | 103 | EXPORT_SYMBOL_GPL(xdr_encode_string); |
1da177e4 | 104 | |
d8ed029d | 105 | __be32 * |
e5cff482 CL |
106 | xdr_decode_string_inplace(__be32 *p, char **sp, |
107 | unsigned int *lenp, unsigned int maxlen) | |
1da177e4 | 108 | { |
e5cff482 | 109 | u32 len; |
1da177e4 | 110 | |
98866b5a | 111 | len = be32_to_cpu(*p++); |
e5cff482 | 112 | if (len > maxlen) |
1da177e4 LT |
113 | return NULL; |
114 | *lenp = len; | |
115 | *sp = (char *) p; | |
116 | return p + XDR_QUADLEN(len); | |
117 | } | |
468039ee | 118 | EXPORT_SYMBOL_GPL(xdr_decode_string_inplace); |
1da177e4 | 119 | |
b4687da7 CL |
120 | /** |
121 | * xdr_terminate_string - '\0'-terminate a string residing in an xdr_buf | |
122 | * @buf: XDR buffer where string resides | |
123 | * @len: length of string, in bytes | |
124 | * | |
125 | */ | |
f8d0e60f | 126 | void xdr_terminate_string(const struct xdr_buf *buf, const u32 len) |
b4687da7 CL |
127 | { |
128 | char *kaddr; | |
129 | ||
b8541786 | 130 | kaddr = kmap_atomic(buf->pages[0]); |
b4687da7 | 131 | kaddr[buf->page_base + len] = '\0'; |
b8541786 | 132 | kunmap_atomic(kaddr); |
b4687da7 | 133 | } |
0d961aa9 | 134 | EXPORT_SYMBOL_GPL(xdr_terminate_string); |
b4687da7 | 135 | |
f8d0e60f | 136 | size_t xdr_buf_pagecount(const struct xdr_buf *buf) |
9d96acbc TM |
137 | { |
138 | if (!buf->page_len) | |
139 | return 0; | |
140 | return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
141 | } | |
142 | ||
143 | int | |
144 | xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp) | |
145 | { | |
146 | size_t i, n = xdr_buf_pagecount(buf); | |
147 | ||
148 | if (n != 0 && buf->bvec == NULL) { | |
149 | buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp); | |
150 | if (!buf->bvec) | |
151 | return -ENOMEM; | |
152 | for (i = 0; i < n; i++) { | |
153 | buf->bvec[i].bv_page = buf->pages[i]; | |
154 | buf->bvec[i].bv_len = PAGE_SIZE; | |
155 | buf->bvec[i].bv_offset = 0; | |
156 | } | |
157 | } | |
158 | return 0; | |
159 | } | |
160 | ||
161 | void | |
162 | xdr_free_bvec(struct xdr_buf *buf) | |
163 | { | |
164 | kfree(buf->bvec); | |
165 | buf->bvec = NULL; | |
166 | } | |
167 | ||
cf500bac CL |
168 | /** |
169 | * xdr_inline_pages - Prepare receive buffer for a large reply | |
170 | * @xdr: xdr_buf into which reply will be placed | |
171 | * @offset: expected offset where data payload will start, in bytes | |
172 | * @pages: vector of struct page pointers | |
173 | * @base: offset in first page where receive should start, in bytes | |
174 | * @len: expected size of the upper layer data payload, in bytes | |
175 | * | |
176 | */ | |
1da177e4 LT |
177 | void |
178 | xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, | |
179 | struct page **pages, unsigned int base, unsigned int len) | |
180 | { | |
181 | struct kvec *head = xdr->head; | |
182 | struct kvec *tail = xdr->tail; | |
183 | char *buf = (char *)head->iov_base; | |
184 | unsigned int buflen = head->iov_len; | |
185 | ||
186 | head->iov_len = offset; | |
187 | ||
188 | xdr->pages = pages; | |
189 | xdr->page_base = base; | |
190 | xdr->page_len = len; | |
191 | ||
192 | tail->iov_base = buf + offset; | |
193 | tail->iov_len = buflen - offset; | |
1da177e4 LT |
194 | xdr->buflen += len; |
195 | } | |
468039ee | 196 | EXPORT_SYMBOL_GPL(xdr_inline_pages); |
1da177e4 | 197 | |
1da177e4 LT |
198 | /* |
199 | * Helper routines for doing 'memmove' like operations on a struct xdr_buf | |
2c53040f BH |
200 | */ |
201 | ||
e6ac0acc AS |
202 | /** |
203 | * _shift_data_left_pages | |
204 | * @pages: vector of pages containing both the source and dest memory area. | |
205 | * @pgto_base: page vector address of destination | |
206 | * @pgfrom_base: page vector address of source | |
207 | * @len: number of bytes to copy | |
208 | * | |
209 | * Note: the addresses pgto_base and pgfrom_base are both calculated in | |
210 | * the same way: | |
211 | * if a memory area starts at byte 'base' in page 'pages[i]', | |
212 | * then its address is given as (i << PAGE_CACHE_SHIFT) + base | |
213 | * Alse note: pgto_base must be < pgfrom_base, but the memory areas | |
214 | * they point to may overlap. | |
215 | */ | |
216 | static void | |
217 | _shift_data_left_pages(struct page **pages, size_t pgto_base, | |
218 | size_t pgfrom_base, size_t len) | |
219 | { | |
220 | struct page **pgfrom, **pgto; | |
221 | char *vfrom, *vto; | |
222 | size_t copy; | |
223 | ||
224 | BUG_ON(pgfrom_base <= pgto_base); | |
225 | ||
c54e959b TM |
226 | if (!len) |
227 | return; | |
228 | ||
e6ac0acc AS |
229 | pgto = pages + (pgto_base >> PAGE_SHIFT); |
230 | pgfrom = pages + (pgfrom_base >> PAGE_SHIFT); | |
231 | ||
232 | pgto_base &= ~PAGE_MASK; | |
233 | pgfrom_base &= ~PAGE_MASK; | |
234 | ||
235 | do { | |
236 | if (pgto_base >= PAGE_SIZE) { | |
237 | pgto_base = 0; | |
238 | pgto++; | |
239 | } | |
240 | if (pgfrom_base >= PAGE_SIZE){ | |
241 | pgfrom_base = 0; | |
242 | pgfrom++; | |
243 | } | |
244 | ||
245 | copy = len; | |
246 | if (copy > (PAGE_SIZE - pgto_base)) | |
247 | copy = PAGE_SIZE - pgto_base; | |
248 | if (copy > (PAGE_SIZE - pgfrom_base)) | |
249 | copy = PAGE_SIZE - pgfrom_base; | |
250 | ||
251 | vto = kmap_atomic(*pgto); | |
252 | if (*pgto != *pgfrom) { | |
253 | vfrom = kmap_atomic(*pgfrom); | |
254 | memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); | |
255 | kunmap_atomic(vfrom); | |
256 | } else | |
257 | memmove(vto + pgto_base, vto + pgfrom_base, copy); | |
258 | flush_dcache_page(*pgto); | |
259 | kunmap_atomic(vto); | |
260 | ||
261 | pgto_base += copy; | |
262 | pgfrom_base += copy; | |
263 | ||
264 | } while ((len -= copy) != 0); | |
265 | } | |
266 | ||
2c53040f | 267 | /** |
1da177e4 LT |
268 | * _shift_data_right_pages |
269 | * @pages: vector of pages containing both the source and dest memory area. | |
270 | * @pgto_base: page vector address of destination | |
271 | * @pgfrom_base: page vector address of source | |
272 | * @len: number of bytes to copy | |
273 | * | |
274 | * Note: the addresses pgto_base and pgfrom_base are both calculated in | |
275 | * the same way: | |
276 | * if a memory area starts at byte 'base' in page 'pages[i]', | |
ea1754a0 | 277 | * then its address is given as (i << PAGE_SHIFT) + base |
1da177e4 LT |
278 | * Also note: pgfrom_base must be < pgto_base, but the memory areas |
279 | * they point to may overlap. | |
280 | */ | |
281 | static void | |
282 | _shift_data_right_pages(struct page **pages, size_t pgto_base, | |
283 | size_t pgfrom_base, size_t len) | |
284 | { | |
285 | struct page **pgfrom, **pgto; | |
286 | char *vfrom, *vto; | |
287 | size_t copy; | |
288 | ||
289 | BUG_ON(pgto_base <= pgfrom_base); | |
290 | ||
c54e959b TM |
291 | if (!len) |
292 | return; | |
293 | ||
1da177e4 LT |
294 | pgto_base += len; |
295 | pgfrom_base += len; | |
296 | ||
09cbfeaf KS |
297 | pgto = pages + (pgto_base >> PAGE_SHIFT); |
298 | pgfrom = pages + (pgfrom_base >> PAGE_SHIFT); | |
1da177e4 | 299 | |
09cbfeaf KS |
300 | pgto_base &= ~PAGE_MASK; |
301 | pgfrom_base &= ~PAGE_MASK; | |
1da177e4 LT |
302 | |
303 | do { | |
304 | /* Are any pointers crossing a page boundary? */ | |
305 | if (pgto_base == 0) { | |
09cbfeaf | 306 | pgto_base = PAGE_SIZE; |
1da177e4 LT |
307 | pgto--; |
308 | } | |
309 | if (pgfrom_base == 0) { | |
09cbfeaf | 310 | pgfrom_base = PAGE_SIZE; |
1da177e4 LT |
311 | pgfrom--; |
312 | } | |
313 | ||
314 | copy = len; | |
315 | if (copy > pgto_base) | |
316 | copy = pgto_base; | |
317 | if (copy > pgfrom_base) | |
318 | copy = pgfrom_base; | |
319 | pgto_base -= copy; | |
320 | pgfrom_base -= copy; | |
321 | ||
b8541786 | 322 | vto = kmap_atomic(*pgto); |
347e2233 TM |
323 | if (*pgto != *pgfrom) { |
324 | vfrom = kmap_atomic(*pgfrom); | |
325 | memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); | |
326 | kunmap_atomic(vfrom); | |
327 | } else | |
328 | memmove(vto + pgto_base, vto + pgfrom_base, copy); | |
bce3481c | 329 | flush_dcache_page(*pgto); |
b8541786 | 330 | kunmap_atomic(vto); |
1da177e4 LT |
331 | |
332 | } while ((len -= copy) != 0); | |
1da177e4 LT |
333 | } |
334 | ||
2c53040f | 335 | /** |
1da177e4 LT |
336 | * _copy_to_pages |
337 | * @pages: array of pages | |
338 | * @pgbase: page vector address of destination | |
339 | * @p: pointer to source data | |
340 | * @len: length | |
341 | * | |
342 | * Copies data from an arbitrary memory location into an array of pages | |
343 | * The copy is assumed to be non-overlapping. | |
344 | */ | |
345 | static void | |
346 | _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len) | |
347 | { | |
348 | struct page **pgto; | |
349 | char *vto; | |
350 | size_t copy; | |
351 | ||
c54e959b TM |
352 | if (!len) |
353 | return; | |
354 | ||
09cbfeaf KS |
355 | pgto = pages + (pgbase >> PAGE_SHIFT); |
356 | pgbase &= ~PAGE_MASK; | |
1da177e4 | 357 | |
daeba89d | 358 | for (;;) { |
09cbfeaf | 359 | copy = PAGE_SIZE - pgbase; |
1da177e4 LT |
360 | if (copy > len) |
361 | copy = len; | |
362 | ||
b8541786 | 363 | vto = kmap_atomic(*pgto); |
1da177e4 | 364 | memcpy(vto + pgbase, p, copy); |
b8541786 | 365 | kunmap_atomic(vto); |
1da177e4 | 366 | |
daeba89d TM |
367 | len -= copy; |
368 | if (len == 0) | |
369 | break; | |
370 | ||
1da177e4 | 371 | pgbase += copy; |
09cbfeaf | 372 | if (pgbase == PAGE_SIZE) { |
1da177e4 LT |
373 | flush_dcache_page(*pgto); |
374 | pgbase = 0; | |
375 | pgto++; | |
376 | } | |
377 | p += copy; | |
daeba89d | 378 | } |
1da177e4 LT |
379 | flush_dcache_page(*pgto); |
380 | } | |
381 | ||
2c53040f | 382 | /** |
1da177e4 LT |
383 | * _copy_from_pages |
384 | * @p: pointer to destination | |
385 | * @pages: array of pages | |
386 | * @pgbase: offset of source data | |
387 | * @len: length | |
388 | * | |
389 | * Copies data into an arbitrary memory location from an array of pages | |
390 | * The copy is assumed to be non-overlapping. | |
391 | */ | |
bf118a34 | 392 | void |
1da177e4 LT |
393 | _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) |
394 | { | |
395 | struct page **pgfrom; | |
396 | char *vfrom; | |
397 | size_t copy; | |
398 | ||
c54e959b TM |
399 | if (!len) |
400 | return; | |
401 | ||
09cbfeaf KS |
402 | pgfrom = pages + (pgbase >> PAGE_SHIFT); |
403 | pgbase &= ~PAGE_MASK; | |
1da177e4 LT |
404 | |
405 | do { | |
09cbfeaf | 406 | copy = PAGE_SIZE - pgbase; |
1da177e4 LT |
407 | if (copy > len) |
408 | copy = len; | |
409 | ||
b8541786 | 410 | vfrom = kmap_atomic(*pgfrom); |
1da177e4 | 411 | memcpy(p, vfrom + pgbase, copy); |
b8541786 | 412 | kunmap_atomic(vfrom); |
1da177e4 LT |
413 | |
414 | pgbase += copy; | |
09cbfeaf | 415 | if (pgbase == PAGE_SIZE) { |
1da177e4 LT |
416 | pgbase = 0; |
417 | pgfrom++; | |
418 | } | |
419 | p += copy; | |
420 | ||
421 | } while ((len -= copy) != 0); | |
422 | } | |
bf118a34 | 423 | EXPORT_SYMBOL_GPL(_copy_from_pages); |
1da177e4 | 424 | |
c4f2f591 TM |
425 | static void xdr_buf_iov_zero(const struct kvec *iov, unsigned int base, |
426 | unsigned int len) | |
427 | { | |
428 | if (base >= iov->iov_len) | |
429 | return; | |
430 | if (len > iov->iov_len - base) | |
431 | len = iov->iov_len - base; | |
432 | memset(iov->iov_base + base, 0, len); | |
433 | } | |
434 | ||
84ce182a | 435 | /** |
c4f2f591 TM |
436 | * xdr_buf_pages_zero |
437 | * @buf: xdr_buf | |
438 | * @pgbase: beginning offset | |
84ce182a AS |
439 | * @len: length |
440 | */ | |
c4f2f591 TM |
441 | static void xdr_buf_pages_zero(const struct xdr_buf *buf, unsigned int pgbase, |
442 | unsigned int len) | |
84ce182a | 443 | { |
c4f2f591 | 444 | struct page **pages = buf->pages; |
84ce182a AS |
445 | struct page **page; |
446 | char *vpage; | |
c4f2f591 TM |
447 | unsigned int zero; |
448 | ||
449 | if (!len) | |
450 | return; | |
451 | if (pgbase >= buf->page_len) { | |
452 | xdr_buf_iov_zero(buf->tail, pgbase - buf->page_len, len); | |
453 | return; | |
454 | } | |
455 | if (pgbase + len > buf->page_len) { | |
456 | xdr_buf_iov_zero(buf->tail, 0, pgbase + len - buf->page_len); | |
457 | len = buf->page_len - pgbase; | |
458 | } | |
459 | ||
460 | pgbase += buf->page_base; | |
84ce182a AS |
461 | |
462 | page = pages + (pgbase >> PAGE_SHIFT); | |
463 | pgbase &= ~PAGE_MASK; | |
464 | ||
465 | do { | |
466 | zero = PAGE_SIZE - pgbase; | |
467 | if (zero > len) | |
468 | zero = len; | |
469 | ||
470 | vpage = kmap_atomic(*page); | |
471 | memset(vpage + pgbase, 0, zero); | |
472 | kunmap_atomic(vpage); | |
473 | ||
474 | flush_dcache_page(*page); | |
475 | pgbase = 0; | |
476 | page++; | |
477 | ||
478 | } while ((len -= zero) != 0); | |
479 | } | |
480 | ||
5802f7c2 TM |
481 | static unsigned int xdr_buf_pages_fill_sparse(const struct xdr_buf *buf, |
482 | unsigned int buflen, gfp_t gfp) | |
483 | { | |
484 | unsigned int i, npages, pagelen; | |
485 | ||
486 | if (!(buf->flags & XDRBUF_SPARSE_PAGES)) | |
487 | return buflen; | |
488 | if (buflen <= buf->head->iov_len) | |
489 | return buflen; | |
490 | pagelen = buflen - buf->head->iov_len; | |
491 | if (pagelen > buf->page_len) | |
492 | pagelen = buf->page_len; | |
493 | npages = (pagelen + buf->page_base + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
494 | for (i = 0; i < npages; i++) { | |
495 | if (!buf->pages[i]) | |
496 | continue; | |
497 | buf->pages[i] = alloc_page(gfp); | |
498 | if (likely(buf->pages[i])) | |
499 | continue; | |
500 | buflen -= pagelen; | |
501 | pagelen = i << PAGE_SHIFT; | |
502 | if (pagelen > buf->page_base) | |
503 | buflen += pagelen - buf->page_base; | |
504 | break; | |
505 | } | |
506 | return buflen; | |
507 | } | |
508 | ||
c4f2f591 TM |
509 | static void xdr_buf_try_expand(struct xdr_buf *buf, unsigned int len) |
510 | { | |
511 | struct kvec *head = buf->head; | |
512 | struct kvec *tail = buf->tail; | |
513 | unsigned int sum = head->iov_len + buf->page_len + tail->iov_len; | |
5802f7c2 | 514 | unsigned int free_space, newlen; |
c4f2f591 TM |
515 | |
516 | if (sum > buf->len) { | |
517 | free_space = min_t(unsigned int, sum - buf->len, len); | |
5802f7c2 TM |
518 | newlen = xdr_buf_pages_fill_sparse(buf, buf->len + free_space, |
519 | GFP_KERNEL); | |
520 | free_space = newlen - buf->len; | |
521 | buf->len = newlen; | |
c4f2f591 TM |
522 | len -= free_space; |
523 | if (!len) | |
524 | return; | |
525 | } | |
526 | ||
527 | if (buf->buflen > sum) { | |
528 | /* Expand the tail buffer */ | |
529 | free_space = min_t(unsigned int, buf->buflen - sum, len); | |
530 | tail->iov_len += free_space; | |
531 | buf->len += free_space; | |
532 | } | |
533 | } | |
534 | ||
535 | static void xdr_buf_tail_copy_right(const struct xdr_buf *buf, | |
536 | unsigned int base, unsigned int len, | |
537 | unsigned int shift) | |
538 | { | |
539 | const struct kvec *tail = buf->tail; | |
540 | unsigned int to = base + shift; | |
541 | ||
542 | if (to >= tail->iov_len) | |
543 | return; | |
544 | if (len + to > tail->iov_len) | |
545 | len = tail->iov_len - to; | |
546 | memmove(tail->iov_base + to, tail->iov_base + base, len); | |
547 | } | |
548 | ||
549 | static void xdr_buf_pages_copy_right(const struct xdr_buf *buf, | |
550 | unsigned int base, unsigned int len, | |
551 | unsigned int shift) | |
552 | { | |
553 | const struct kvec *tail = buf->tail; | |
554 | unsigned int to = base + shift; | |
555 | unsigned int pglen = 0; | |
556 | unsigned int talen = 0, tato = 0; | |
557 | ||
558 | if (base >= buf->page_len) | |
559 | return; | |
560 | if (len > buf->page_len - base) | |
561 | len = buf->page_len - base; | |
562 | if (to >= buf->page_len) { | |
563 | tato = to - buf->page_len; | |
564 | if (tail->iov_len >= len + tato) | |
565 | talen = len; | |
566 | else if (tail->iov_len > tato) | |
567 | talen = tail->iov_len - tato; | |
568 | } else if (len + to >= buf->page_len) { | |
569 | pglen = buf->page_len - to; | |
570 | talen = len - pglen; | |
571 | if (talen > tail->iov_len) | |
572 | talen = tail->iov_len; | |
573 | } else | |
574 | pglen = len; | |
575 | ||
576 | _copy_from_pages(tail->iov_base + tato, buf->pages, | |
577 | buf->page_base + base + pglen, talen); | |
578 | _shift_data_right_pages(buf->pages, buf->page_base + to, | |
579 | buf->page_base + base, pglen); | |
580 | } | |
581 | ||
6707fbd7 TM |
582 | static void xdr_buf_head_copy_right(const struct xdr_buf *buf, |
583 | unsigned int base, unsigned int len, | |
584 | unsigned int shift) | |
585 | { | |
586 | const struct kvec *head = buf->head; | |
587 | const struct kvec *tail = buf->tail; | |
588 | unsigned int to = base + shift; | |
589 | unsigned int pglen = 0, pgto = 0; | |
590 | unsigned int talen = 0, tato = 0; | |
591 | ||
592 | if (base >= head->iov_len) | |
593 | return; | |
594 | if (len > head->iov_len - base) | |
595 | len = head->iov_len - base; | |
596 | if (to >= buf->page_len + head->iov_len) { | |
597 | tato = to - buf->page_len - head->iov_len; | |
598 | talen = len; | |
599 | } else if (to >= head->iov_len) { | |
600 | pgto = to - head->iov_len; | |
601 | pglen = len; | |
602 | if (pgto + pglen > buf->page_len) { | |
603 | talen = pgto + pglen - buf->page_len; | |
604 | pglen -= talen; | |
605 | } | |
606 | } else { | |
607 | pglen = len - to; | |
608 | if (pglen > buf->page_len) { | |
609 | talen = pglen - buf->page_len; | |
610 | pglen = buf->page_len; | |
611 | } | |
612 | } | |
613 | ||
614 | len -= talen; | |
615 | base += len; | |
616 | if (talen + tato > tail->iov_len) | |
617 | talen = tail->iov_len > tato ? tail->iov_len - tato : 0; | |
618 | memcpy(tail->iov_base + tato, head->iov_base + base, talen); | |
619 | ||
620 | len -= pglen; | |
621 | base -= pglen; | |
622 | _copy_to_pages(buf->pages, buf->page_base + pgto, head->iov_base + base, | |
623 | pglen); | |
624 | ||
625 | base -= len; | |
626 | memmove(head->iov_base + to, head->iov_base + base, len); | |
627 | } | |
628 | ||
c4f2f591 TM |
629 | static void xdr_buf_tail_shift_right(const struct xdr_buf *buf, |
630 | unsigned int base, unsigned int len, | |
631 | unsigned int shift) | |
632 | { | |
633 | const struct kvec *tail = buf->tail; | |
634 | ||
635 | if (base >= tail->iov_len || !shift || !len) | |
636 | return; | |
637 | xdr_buf_tail_copy_right(buf, base, len, shift); | |
638 | } | |
639 | ||
640 | static void xdr_buf_pages_shift_right(const struct xdr_buf *buf, | |
641 | unsigned int base, unsigned int len, | |
642 | unsigned int shift) | |
643 | { | |
644 | if (!shift || !len) | |
645 | return; | |
646 | if (base >= buf->page_len) { | |
647 | xdr_buf_tail_shift_right(buf, base - buf->page_len, len, shift); | |
648 | return; | |
649 | } | |
650 | if (base + len > buf->page_len) | |
651 | xdr_buf_tail_shift_right(buf, 0, base + len - buf->page_len, | |
652 | shift); | |
653 | xdr_buf_pages_copy_right(buf, base, len, shift); | |
654 | } | |
655 | ||
6707fbd7 TM |
656 | static void xdr_buf_head_shift_right(const struct xdr_buf *buf, |
657 | unsigned int base, unsigned int len, | |
658 | unsigned int shift) | |
659 | { | |
660 | const struct kvec *head = buf->head; | |
661 | ||
662 | if (!shift) | |
663 | return; | |
664 | if (base >= head->iov_len) { | |
665 | xdr_buf_pages_shift_right(buf, head->iov_len - base, len, | |
666 | shift); | |
667 | return; | |
668 | } | |
669 | if (base + len > head->iov_len) | |
670 | xdr_buf_pages_shift_right(buf, 0, base + len - head->iov_len, | |
671 | shift); | |
672 | xdr_buf_head_copy_right(buf, base, len, shift); | |
673 | } | |
674 | ||
9a20f6f4 TM |
675 | static void xdr_buf_tail_copy_left(const struct xdr_buf *buf, unsigned int base, |
676 | unsigned int len, unsigned int shift) | |
677 | { | |
678 | const struct kvec *tail = buf->tail; | |
679 | ||
680 | if (base >= tail->iov_len) | |
681 | return; | |
682 | if (len > tail->iov_len - base) | |
683 | len = tail->iov_len - base; | |
684 | /* Shift data into head */ | |
685 | if (shift > buf->page_len + base) { | |
686 | const struct kvec *head = buf->head; | |
687 | unsigned int hdto = | |
688 | head->iov_len + buf->page_len + base - shift; | |
689 | unsigned int hdlen = len; | |
690 | ||
691 | if (WARN_ONCE(shift > head->iov_len + buf->page_len + base, | |
692 | "SUNRPC: Misaligned data.\n")) | |
693 | return; | |
694 | if (hdto + hdlen > head->iov_len) | |
695 | hdlen = head->iov_len - hdto; | |
696 | memcpy(head->iov_base + hdto, tail->iov_base + base, hdlen); | |
697 | base += hdlen; | |
698 | len -= hdlen; | |
699 | if (!len) | |
700 | return; | |
701 | } | |
702 | /* Shift data into pages */ | |
703 | if (shift > base) { | |
704 | unsigned int pgto = buf->page_len + base - shift; | |
705 | unsigned int pglen = len; | |
706 | ||
707 | if (pgto + pglen > buf->page_len) | |
708 | pglen = buf->page_len - pgto; | |
709 | _copy_to_pages(buf->pages, buf->page_base + pgto, | |
710 | tail->iov_base + base, pglen); | |
711 | base += pglen; | |
712 | len -= pglen; | |
713 | if (!len) | |
714 | return; | |
715 | } | |
716 | memmove(tail->iov_base + base - shift, tail->iov_base + base, len); | |
717 | } | |
718 | ||
719 | static void xdr_buf_pages_copy_left(const struct xdr_buf *buf, | |
720 | unsigned int base, unsigned int len, | |
721 | unsigned int shift) | |
722 | { | |
723 | unsigned int pgto; | |
724 | ||
725 | if (base >= buf->page_len) | |
726 | return; | |
727 | if (len > buf->page_len - base) | |
728 | len = buf->page_len - base; | |
729 | /* Shift data into head */ | |
730 | if (shift > base) { | |
731 | const struct kvec *head = buf->head; | |
732 | unsigned int hdto = head->iov_len + base - shift; | |
733 | unsigned int hdlen = len; | |
734 | ||
735 | if (WARN_ONCE(shift > head->iov_len + base, | |
736 | "SUNRPC: Misaligned data.\n")) | |
737 | return; | |
738 | if (hdto + hdlen > head->iov_len) | |
739 | hdlen = head->iov_len - hdto; | |
740 | _copy_from_pages(head->iov_base + hdto, buf->pages, | |
741 | buf->page_base + base, hdlen); | |
742 | base += hdlen; | |
743 | len -= hdlen; | |
744 | if (!len) | |
745 | return; | |
746 | } | |
747 | pgto = base - shift; | |
748 | _shift_data_left_pages(buf->pages, buf->page_base + pgto, | |
749 | buf->page_base + base, len); | |
750 | } | |
751 | ||
752 | static void xdr_buf_tail_shift_left(const struct xdr_buf *buf, | |
753 | unsigned int base, unsigned int len, | |
754 | unsigned int shift) | |
755 | { | |
756 | if (!shift || !len) | |
757 | return; | |
758 | xdr_buf_tail_copy_left(buf, base, len, shift); | |
759 | } | |
760 | ||
761 | static void xdr_buf_pages_shift_left(const struct xdr_buf *buf, | |
762 | unsigned int base, unsigned int len, | |
763 | unsigned int shift) | |
764 | { | |
765 | if (!shift || !len) | |
766 | return; | |
767 | if (base >= buf->page_len) { | |
768 | xdr_buf_tail_shift_left(buf, base - buf->page_len, len, shift); | |
769 | return; | |
770 | } | |
771 | xdr_buf_pages_copy_left(buf, base, len, shift); | |
772 | len += base; | |
773 | if (len <= buf->page_len) | |
774 | return; | |
775 | xdr_buf_tail_copy_left(buf, 0, len - buf->page_len, shift); | |
776 | } | |
777 | ||
2c53040f | 778 | /** |
1da177e4 LT |
779 | * xdr_shrink_bufhead |
780 | * @buf: xdr_buf | |
6707fbd7 | 781 | * @len: new length of buf->head[0] |
1da177e4 | 782 | * |
6707fbd7 | 783 | * Shrinks XDR buffer's header kvec buf->head[0], setting it to |
1da177e4 LT |
784 | * 'len' bytes. The extra data is not lost, but is instead |
785 | * moved into the inlined pages and/or the tail. | |
786 | */ | |
6707fbd7 | 787 | static unsigned int xdr_shrink_bufhead(struct xdr_buf *buf, unsigned int len) |
1da177e4 | 788 | { |
6707fbd7 TM |
789 | struct kvec *head = buf->head; |
790 | unsigned int shift, buflen = max(buf->len, len); | |
18e624ad WAA |
791 | |
792 | WARN_ON_ONCE(len > head->iov_len); | |
6707fbd7 TM |
793 | if (head->iov_len > buflen) { |
794 | buf->buflen -= head->iov_len - buflen; | |
795 | head->iov_len = buflen; | |
1da177e4 | 796 | } |
6707fbd7 TM |
797 | if (len >= head->iov_len) |
798 | return 0; | |
799 | shift = head->iov_len - len; | |
800 | xdr_buf_try_expand(buf, shift); | |
801 | xdr_buf_head_shift_right(buf, len, buflen - len, shift); | |
802 | head->iov_len = len; | |
803 | buf->buflen -= shift; | |
804 | buf->len -= shift; | |
805 | return shift; | |
1da177e4 LT |
806 | } |
807 | ||
2c53040f | 808 | /** |
c4f2f591 | 809 | * xdr_shrink_pagelen - shrinks buf->pages to @len bytes |
1da177e4 | 810 | * @buf: xdr_buf |
c4f2f591 | 811 | * @len: new page buffer length |
1da177e4 | 812 | * |
e8d70b32 CL |
813 | * The extra data is not lost, but is instead moved into buf->tail. |
814 | * Returns the actual number of bytes moved. | |
1da177e4 | 815 | */ |
c4f2f591 | 816 | static unsigned int xdr_shrink_pagelen(struct xdr_buf *buf, unsigned int len) |
1da177e4 | 817 | { |
c4f2f591 | 818 | unsigned int shift, buflen = buf->len - buf->head->iov_len; |
1da177e4 | 819 | |
c4f2f591 TM |
820 | WARN_ON_ONCE(len > buf->page_len); |
821 | if (buf->head->iov_len >= buf->len || len > buflen) | |
822 | buflen = len; | |
823 | if (buf->page_len > buflen) { | |
824 | buf->buflen -= buf->page_len - buflen; | |
825 | buf->page_len = buflen; | |
826 | } | |
827 | if (len >= buf->page_len) | |
828 | return 0; | |
829 | shift = buf->page_len - len; | |
830 | xdr_buf_try_expand(buf, shift); | |
831 | xdr_buf_pages_shift_right(buf, len, buflen - len, shift); | |
832 | buf->page_len = len; | |
833 | buf->len -= shift; | |
834 | buf->buflen -= shift; | |
835 | return shift; | |
1da177e4 LT |
836 | } |
837 | ||
838 | void | |
839 | xdr_shift_buf(struct xdr_buf *buf, size_t len) | |
840 | { | |
6707fbd7 | 841 | xdr_shrink_bufhead(buf, buf->head->iov_len - len); |
1da177e4 | 842 | } |
468039ee | 843 | EXPORT_SYMBOL_GPL(xdr_shift_buf); |
1da177e4 | 844 | |
4517d526 TM |
845 | /** |
846 | * xdr_stream_pos - Return the current offset from the start of the xdr_stream | |
847 | * @xdr: pointer to struct xdr_stream | |
848 | */ | |
849 | unsigned int xdr_stream_pos(const struct xdr_stream *xdr) | |
850 | { | |
851 | return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2; | |
852 | } | |
853 | EXPORT_SYMBOL_GPL(xdr_stream_pos); | |
854 | ||
c4f2f591 TM |
855 | static void xdr_stream_set_pos(struct xdr_stream *xdr, unsigned int pos) |
856 | { | |
857 | unsigned int blen = xdr->buf->len; | |
858 | ||
859 | xdr->nwords = blen > pos ? XDR_QUADLEN(blen) - XDR_QUADLEN(pos) : 0; | |
860 | } | |
861 | ||
862 | static void xdr_stream_page_set_pos(struct xdr_stream *xdr, unsigned int pos) | |
863 | { | |
864 | xdr_stream_set_pos(xdr, pos + xdr->buf->head[0].iov_len); | |
865 | } | |
866 | ||
cf1f08ca AS |
867 | /** |
868 | * xdr_page_pos - Return the current offset from the start of the xdr pages | |
869 | * @xdr: pointer to struct xdr_stream | |
870 | */ | |
871 | unsigned int xdr_page_pos(const struct xdr_stream *xdr) | |
872 | { | |
873 | unsigned int pos = xdr_stream_pos(xdr); | |
874 | ||
875 | WARN_ON(pos < xdr->buf->head[0].iov_len); | |
876 | return pos - xdr->buf->head[0].iov_len; | |
877 | } | |
878 | EXPORT_SYMBOL_GPL(xdr_page_pos); | |
879 | ||
1da177e4 LT |
880 | /** |
881 | * xdr_init_encode - Initialize a struct xdr_stream for sending data. | |
882 | * @xdr: pointer to xdr_stream struct | |
883 | * @buf: pointer to XDR buffer in which to encode data | |
884 | * @p: current pointer inside XDR buffer | |
0ccc61b1 | 885 | * @rqst: pointer to controlling rpc_rqst, for debugging |
1da177e4 LT |
886 | * |
887 | * Note: at the moment the RPC client only passes the length of our | |
888 | * scratch buffer in the xdr_buf's header kvec. Previously this | |
889 | * meant we needed to call xdr_adjust_iovec() after encoding the | |
890 | * data. With the new scheme, the xdr_stream manages the details | |
891 | * of the buffer length, and takes care of adjusting the kvec | |
892 | * length for us. | |
893 | */ | |
0ccc61b1 CL |
894 | void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
895 | struct rpc_rqst *rqst) | |
1da177e4 LT |
896 | { |
897 | struct kvec *iov = buf->head; | |
334ccfd5 | 898 | int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len; |
1da177e4 | 899 | |
0ae4c3e8 | 900 | xdr_reset_scratch_buffer(xdr); |
334ccfd5 | 901 | BUG_ON(scratch_len < 0); |
1da177e4 LT |
902 | xdr->buf = buf; |
903 | xdr->iov = iov; | |
d8ed029d AD |
904 | xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len); |
905 | xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len); | |
334ccfd5 TM |
906 | BUG_ON(iov->iov_len > scratch_len); |
907 | ||
908 | if (p != xdr->p && p != NULL) { | |
909 | size_t len; | |
910 | ||
911 | BUG_ON(p < xdr->p || p > xdr->end); | |
912 | len = (char *)p - (char *)xdr->p; | |
913 | xdr->p = p; | |
914 | buf->len += len; | |
915 | iov->iov_len += len; | |
916 | } | |
0ccc61b1 | 917 | xdr->rqst = rqst; |
1da177e4 | 918 | } |
468039ee | 919 | EXPORT_SYMBOL_GPL(xdr_init_encode); |
1da177e4 | 920 | |
2825a7f9 BF |
921 | /** |
922 | * xdr_commit_encode - Ensure all data is written to buffer | |
923 | * @xdr: pointer to xdr_stream | |
924 | * | |
925 | * We handle encoding across page boundaries by giving the caller a | |
926 | * temporary location to write to, then later copying the data into | |
927 | * place; xdr_commit_encode does that copying. | |
928 | * | |
929 | * Normally the caller doesn't need to call this directly, as the | |
930 | * following xdr_reserve_space will do it. But an explicit call may be | |
931 | * required at the end of encoding, or any other time when the xdr_buf | |
932 | * data might be read. | |
933 | */ | |
95bd8304 | 934 | inline void xdr_commit_encode(struct xdr_stream *xdr) |
2825a7f9 BF |
935 | { |
936 | int shift = xdr->scratch.iov_len; | |
937 | void *page; | |
938 | ||
939 | if (shift == 0) | |
940 | return; | |
941 | page = page_address(*xdr->page_ptr); | |
942 | memcpy(xdr->scratch.iov_base, page, shift); | |
943 | memmove(page, page + shift, (void *)xdr->p - page); | |
0ae4c3e8 | 944 | xdr_reset_scratch_buffer(xdr); |
2825a7f9 BF |
945 | } |
946 | EXPORT_SYMBOL_GPL(xdr_commit_encode); | |
947 | ||
22cb4385 TM |
948 | static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, |
949 | size_t nbytes) | |
2825a7f9 | 950 | { |
025911a5 | 951 | __be32 *p; |
2825a7f9 BF |
952 | int space_left; |
953 | int frag1bytes, frag2bytes; | |
954 | ||
955 | if (nbytes > PAGE_SIZE) | |
5582863f | 956 | goto out_overflow; /* Bigger buffers require special handling */ |
2825a7f9 | 957 | if (xdr->buf->len + nbytes > xdr->buf->buflen) |
5582863f | 958 | goto out_overflow; /* Sorry, we're totally out of space */ |
2825a7f9 BF |
959 | frag1bytes = (xdr->end - xdr->p) << 2; |
960 | frag2bytes = nbytes - frag1bytes; | |
961 | if (xdr->iov) | |
962 | xdr->iov->iov_len += frag1bytes; | |
05638dc7 | 963 | else |
2825a7f9 | 964 | xdr->buf->page_len += frag1bytes; |
05638dc7 | 965 | xdr->page_ptr++; |
2825a7f9 BF |
966 | xdr->iov = NULL; |
967 | /* | |
968 | * If the last encode didn't end exactly on a page boundary, the | |
969 | * next one will straddle boundaries. Encode into the next | |
970 | * page, then copy it back later in xdr_commit_encode. We use | |
971 | * the "scratch" iov to track any temporarily unused fragment of | |
972 | * space at the end of the previous buffer: | |
973 | */ | |
0ae4c3e8 | 974 | xdr_set_scratch_buffer(xdr, xdr->p, frag1bytes); |
2825a7f9 BF |
975 | p = page_address(*xdr->page_ptr); |
976 | /* | |
977 | * Note this is where the next encode will start after we've | |
978 | * shifted this one back: | |
979 | */ | |
980 | xdr->p = (void *)p + frag2bytes; | |
981 | space_left = xdr->buf->buflen - xdr->buf->len; | |
6c254bf3 CL |
982 | if (space_left - nbytes >= PAGE_SIZE) |
983 | xdr->end = (void *)p + PAGE_SIZE; | |
984 | else | |
985 | xdr->end = (void *)p + space_left - frag1bytes; | |
986 | ||
2825a7f9 BF |
987 | xdr->buf->page_len += frag2bytes; |
988 | xdr->buf->len += nbytes; | |
989 | return p; | |
5582863f CL |
990 | out_overflow: |
991 | trace_rpc_xdr_overflow(xdr, nbytes); | |
992 | return NULL; | |
2825a7f9 BF |
993 | } |
994 | ||
1da177e4 LT |
995 | /** |
996 | * xdr_reserve_space - Reserve buffer space for sending | |
997 | * @xdr: pointer to xdr_stream | |
998 | * @nbytes: number of bytes to reserve | |
999 | * | |
1000 | * Checks that we have enough buffer space to encode 'nbytes' more | |
1001 | * bytes of data. If so, update the total xdr_buf length, and | |
1002 | * adjust the length of the current kvec. | |
1003 | */ | |
d8ed029d | 1004 | __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 1005 | { |
d8ed029d AD |
1006 | __be32 *p = xdr->p; |
1007 | __be32 *q; | |
1da177e4 | 1008 | |
2825a7f9 | 1009 | xdr_commit_encode(xdr); |
1da177e4 LT |
1010 | /* align nbytes on the next 32-bit boundary */ |
1011 | nbytes += 3; | |
1012 | nbytes &= ~3; | |
1013 | q = p + (nbytes >> 2); | |
1014 | if (unlikely(q > xdr->end || q < p)) | |
2825a7f9 | 1015 | return xdr_get_next_encode_buffer(xdr, nbytes); |
1da177e4 | 1016 | xdr->p = q; |
2825a7f9 BF |
1017 | if (xdr->iov) |
1018 | xdr->iov->iov_len += nbytes; | |
1019 | else | |
1020 | xdr->buf->page_len += nbytes; | |
1da177e4 LT |
1021 | xdr->buf->len += nbytes; |
1022 | return p; | |
1023 | } | |
468039ee | 1024 | EXPORT_SYMBOL_GPL(xdr_reserve_space); |
1da177e4 | 1025 | |
403217f3 AS |
1026 | |
1027 | /** | |
1028 | * xdr_reserve_space_vec - Reserves a large amount of buffer space for sending | |
1029 | * @xdr: pointer to xdr_stream | |
1030 | * @vec: pointer to a kvec array | |
1031 | * @nbytes: number of bytes to reserve | |
1032 | * | |
1033 | * Reserves enough buffer space to encode 'nbytes' of data and stores the | |
1034 | * pointers in 'vec'. The size argument passed to xdr_reserve_space() is | |
1035 | * determined based on the number of bytes remaining in the current page to | |
1036 | * avoid invalidating iov_base pointers when xdr_commit_encode() is called. | |
1037 | */ | |
1038 | int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbytes) | |
1039 | { | |
1040 | int thislen; | |
1041 | int v = 0; | |
1042 | __be32 *p; | |
1043 | ||
1044 | /* | |
1045 | * svcrdma requires every READ payload to start somewhere | |
1046 | * in xdr->pages. | |
1047 | */ | |
1048 | if (xdr->iov == xdr->buf->head) { | |
1049 | xdr->iov = NULL; | |
1050 | xdr->end = xdr->p; | |
1051 | } | |
1052 | ||
1053 | while (nbytes) { | |
1054 | thislen = xdr->buf->page_len % PAGE_SIZE; | |
1055 | thislen = min_t(size_t, nbytes, PAGE_SIZE - thislen); | |
1056 | ||
1057 | p = xdr_reserve_space(xdr, thislen); | |
1058 | if (!p) | |
1059 | return -EIO; | |
1060 | ||
1061 | vec[v].iov_base = p; | |
1062 | vec[v].iov_len = thislen; | |
1063 | v++; | |
1064 | nbytes -= thislen; | |
1065 | } | |
1066 | ||
1067 | return v; | |
1068 | } | |
1069 | EXPORT_SYMBOL_GPL(xdr_reserve_space_vec); | |
1070 | ||
3e19ce76 BF |
1071 | /** |
1072 | * xdr_truncate_encode - truncate an encode buffer | |
1073 | * @xdr: pointer to xdr_stream | |
1074 | * @len: new length of buffer | |
1075 | * | |
1076 | * Truncates the xdr stream, so that xdr->buf->len == len, | |
1077 | * and xdr->p points at offset len from the start of the buffer, and | |
1078 | * head, tail, and page lengths are adjusted to correspond. | |
1079 | * | |
1080 | * If this means moving xdr->p to a different buffer, we assume that | |
1cc5213b | 1081 | * the end pointer should be set to the end of the current page, |
3e19ce76 BF |
1082 | * except in the case of the head buffer when we assume the head |
1083 | * buffer's current length represents the end of the available buffer. | |
1084 | * | |
1085 | * This is *not* safe to use on a buffer that already has inlined page | |
1086 | * cache pages (as in a zero-copy server read reply), except for the | |
1087 | * simple case of truncating from one position in the tail to another. | |
1088 | * | |
1089 | */ | |
1090 | void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) | |
1091 | { | |
1092 | struct xdr_buf *buf = xdr->buf; | |
1093 | struct kvec *head = buf->head; | |
1094 | struct kvec *tail = buf->tail; | |
1095 | int fraglen; | |
49a068f8 | 1096 | int new; |
3e19ce76 BF |
1097 | |
1098 | if (len > buf->len) { | |
1099 | WARN_ON_ONCE(1); | |
1100 | return; | |
1101 | } | |
2825a7f9 | 1102 | xdr_commit_encode(xdr); |
3e19ce76 BF |
1103 | |
1104 | fraglen = min_t(int, buf->len - len, tail->iov_len); | |
1105 | tail->iov_len -= fraglen; | |
1106 | buf->len -= fraglen; | |
ed38c069 | 1107 | if (tail->iov_len) { |
3e19ce76 | 1108 | xdr->p = tail->iov_base + tail->iov_len; |
280caac0 BF |
1109 | WARN_ON_ONCE(!xdr->end); |
1110 | WARN_ON_ONCE(!xdr->iov); | |
3e19ce76 BF |
1111 | return; |
1112 | } | |
1113 | WARN_ON_ONCE(fraglen); | |
1114 | fraglen = min_t(int, buf->len - len, buf->page_len); | |
1115 | buf->page_len -= fraglen; | |
1116 | buf->len -= fraglen; | |
1117 | ||
1118 | new = buf->page_base + buf->page_len; | |
49a068f8 BF |
1119 | |
1120 | xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT); | |
3e19ce76 | 1121 | |
ed38c069 | 1122 | if (buf->page_len) { |
3e19ce76 BF |
1123 | xdr->p = page_address(*xdr->page_ptr); |
1124 | xdr->end = (void *)xdr->p + PAGE_SIZE; | |
1125 | xdr->p = (void *)xdr->p + (new % PAGE_SIZE); | |
280caac0 | 1126 | WARN_ON_ONCE(xdr->iov); |
3e19ce76 BF |
1127 | return; |
1128 | } | |
5d7a5bcb | 1129 | if (fraglen) |
3e19ce76 BF |
1130 | xdr->end = head->iov_base + head->iov_len; |
1131 | /* (otherwise assume xdr->end is already set) */ | |
5d7a5bcb | 1132 | xdr->page_ptr--; |
3e19ce76 BF |
1133 | head->iov_len = len; |
1134 | buf->len = len; | |
1135 | xdr->p = head->iov_base + head->iov_len; | |
1136 | xdr->iov = buf->head; | |
1137 | } | |
1138 | EXPORT_SYMBOL(xdr_truncate_encode); | |
1139 | ||
db3f58a9 BF |
1140 | /** |
1141 | * xdr_restrict_buflen - decrease available buffer space | |
1142 | * @xdr: pointer to xdr_stream | |
1143 | * @newbuflen: new maximum number of bytes available | |
1144 | * | |
1145 | * Adjust our idea of how much space is available in the buffer. | |
1146 | * If we've already used too much space in the buffer, returns -1. | |
1147 | * If the available space is already smaller than newbuflen, returns 0 | |
1148 | * and does nothing. Otherwise, adjusts xdr->buf->buflen to newbuflen | |
1149 | * and ensures xdr->end is set at most offset newbuflen from the start | |
1150 | * of the buffer. | |
1151 | */ | |
1152 | int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen) | |
1153 | { | |
1154 | struct xdr_buf *buf = xdr->buf; | |
1155 | int left_in_this_buf = (void *)xdr->end - (void *)xdr->p; | |
1156 | int end_offset = buf->len + left_in_this_buf; | |
1157 | ||
1158 | if (newbuflen < 0 || newbuflen < buf->len) | |
1159 | return -1; | |
1160 | if (newbuflen > buf->buflen) | |
1161 | return 0; | |
1162 | if (newbuflen < end_offset) | |
1163 | xdr->end = (void *)xdr->end + newbuflen - end_offset; | |
1164 | buf->buflen = newbuflen; | |
1165 | return 0; | |
1166 | } | |
1167 | EXPORT_SYMBOL(xdr_restrict_buflen); | |
1168 | ||
1da177e4 LT |
1169 | /** |
1170 | * xdr_write_pages - Insert a list of pages into an XDR buffer for sending | |
1171 | * @xdr: pointer to xdr_stream | |
1172 | * @pages: list of pages | |
1173 | * @base: offset of first byte | |
1174 | * @len: length of data in bytes | |
1175 | * | |
1176 | */ | |
1177 | void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, | |
1178 | unsigned int len) | |
1179 | { | |
1180 | struct xdr_buf *buf = xdr->buf; | |
1181 | struct kvec *iov = buf->tail; | |
1182 | buf->pages = pages; | |
1183 | buf->page_base = base; | |
1184 | buf->page_len = len; | |
1185 | ||
1186 | iov->iov_base = (char *)xdr->p; | |
1187 | iov->iov_len = 0; | |
1188 | xdr->iov = iov; | |
1189 | ||
1190 | if (len & 3) { | |
1191 | unsigned int pad = 4 - (len & 3); | |
1192 | ||
1193 | BUG_ON(xdr->p >= xdr->end); | |
1194 | iov->iov_base = (char *)xdr->p + (len & 3); | |
1195 | iov->iov_len += pad; | |
1196 | len += pad; | |
1197 | *xdr->p++ = 0; | |
1198 | } | |
1199 | buf->buflen += len; | |
1200 | buf->len += len; | |
1201 | } | |
468039ee | 1202 | EXPORT_SYMBOL_GPL(xdr_write_pages); |
1da177e4 | 1203 | |
8d86e373 TM |
1204 | static unsigned int xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov, |
1205 | unsigned int base, unsigned int len) | |
6650239a TM |
1206 | { |
1207 | if (len > iov->iov_len) | |
1208 | len = iov->iov_len; | |
8d86e373 TM |
1209 | if (unlikely(base > len)) |
1210 | base = len; | |
1211 | xdr->p = (__be32*)(iov->iov_base + base); | |
6650239a TM |
1212 | xdr->end = (__be32*)(iov->iov_base + len); |
1213 | xdr->iov = iov; | |
1214 | xdr->page_ptr = NULL; | |
8d86e373 | 1215 | return len - base; |
6650239a TM |
1216 | } |
1217 | ||
5a5f1c2c TM |
1218 | static unsigned int xdr_set_tail_base(struct xdr_stream *xdr, |
1219 | unsigned int base, unsigned int len) | |
1220 | { | |
1221 | struct xdr_buf *buf = xdr->buf; | |
1222 | ||
1223 | xdr_stream_set_pos(xdr, base + buf->page_len + buf->head->iov_len); | |
1224 | return xdr_set_iov(xdr, buf->tail, base, len); | |
6650239a TM |
1225 | } |
1226 | ||
8d86e373 TM |
1227 | static unsigned int xdr_set_page_base(struct xdr_stream *xdr, |
1228 | unsigned int base, unsigned int len) | |
6650239a TM |
1229 | { |
1230 | unsigned int pgnr; | |
1231 | unsigned int maxlen; | |
1232 | unsigned int pgoff; | |
1233 | unsigned int pgend; | |
1234 | void *kaddr; | |
1235 | ||
1236 | maxlen = xdr->buf->page_len; | |
6d1c0f3d AS |
1237 | if (base >= maxlen) |
1238 | return 0; | |
1239 | else | |
8d86e373 | 1240 | maxlen -= base; |
6650239a TM |
1241 | if (len > maxlen) |
1242 | len = maxlen; | |
1243 | ||
5a5f1c2c | 1244 | xdr_stream_page_set_pos(xdr, base); |
6650239a TM |
1245 | base += xdr->buf->page_base; |
1246 | ||
1247 | pgnr = base >> PAGE_SHIFT; | |
1248 | xdr->page_ptr = &xdr->buf->pages[pgnr]; | |
1249 | kaddr = page_address(*xdr->page_ptr); | |
1250 | ||
1251 | pgoff = base & ~PAGE_MASK; | |
1252 | xdr->p = (__be32*)(kaddr + pgoff); | |
1253 | ||
1254 | pgend = pgoff + len; | |
1255 | if (pgend > PAGE_SIZE) | |
1256 | pgend = PAGE_SIZE; | |
1257 | xdr->end = (__be32*)(kaddr + pgend); | |
1258 | xdr->iov = NULL; | |
8d86e373 | 1259 | return len; |
6650239a TM |
1260 | } |
1261 | ||
f7d61ee4 AS |
1262 | static void xdr_set_page(struct xdr_stream *xdr, unsigned int base, |
1263 | unsigned int len) | |
1264 | { | |
0279024f TM |
1265 | if (xdr_set_page_base(xdr, base, len) == 0) { |
1266 | base -= xdr->buf->page_len; | |
5a5f1c2c | 1267 | xdr_set_tail_base(xdr, base, len); |
0279024f | 1268 | } |
f7d61ee4 AS |
1269 | } |
1270 | ||
6650239a TM |
1271 | static void xdr_set_next_page(struct xdr_stream *xdr) |
1272 | { | |
1273 | unsigned int newbase; | |
1274 | ||
1275 | newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT; | |
1276 | newbase -= xdr->buf->page_base; | |
0279024f TM |
1277 | if (newbase < xdr->buf->page_len) |
1278 | xdr_set_page_base(xdr, newbase, xdr_stream_remaining(xdr)); | |
1279 | else | |
5a5f1c2c | 1280 | xdr_set_tail_base(xdr, 0, xdr_stream_remaining(xdr)); |
6650239a TM |
1281 | } |
1282 | ||
1283 | static bool xdr_set_next_buffer(struct xdr_stream *xdr) | |
1284 | { | |
1285 | if (xdr->page_ptr != NULL) | |
1286 | xdr_set_next_page(xdr); | |
0279024f TM |
1287 | else if (xdr->iov == xdr->buf->head) |
1288 | xdr_set_page(xdr, 0, xdr_stream_remaining(xdr)); | |
6650239a TM |
1289 | return xdr->p != xdr->end; |
1290 | } | |
1291 | ||
1da177e4 LT |
1292 | /** |
1293 | * xdr_init_decode - Initialize an xdr_stream for decoding data. | |
1294 | * @xdr: pointer to xdr_stream struct | |
1295 | * @buf: pointer to XDR buffer from which to decode data | |
1296 | * @p: current pointer inside XDR buffer | |
0ccc61b1 | 1297 | * @rqst: pointer to controlling rpc_rqst, for debugging |
1da177e4 | 1298 | */ |
0ccc61b1 CL |
1299 | void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
1300 | struct rpc_rqst *rqst) | |
1da177e4 | 1301 | { |
1da177e4 | 1302 | xdr->buf = buf; |
0ae4c3e8 | 1303 | xdr_reset_scratch_buffer(xdr); |
bfeea1dc | 1304 | xdr->nwords = XDR_QUADLEN(buf->len); |
8d86e373 TM |
1305 | if (xdr_set_iov(xdr, buf->head, 0, buf->len) == 0 && |
1306 | xdr_set_page_base(xdr, 0, buf->len) == 0) | |
1307 | xdr_set_iov(xdr, buf->tail, 0, buf->len); | |
bfeea1dc TM |
1308 | if (p != NULL && p > xdr->p && xdr->end >= p) { |
1309 | xdr->nwords -= p - xdr->p; | |
1537693c | 1310 | xdr->p = p; |
bfeea1dc | 1311 | } |
0ccc61b1 | 1312 | xdr->rqst = rqst; |
1da177e4 | 1313 | } |
468039ee | 1314 | EXPORT_SYMBOL_GPL(xdr_init_decode); |
1da177e4 | 1315 | |
f7da7a12 | 1316 | /** |
7ecce75f | 1317 | * xdr_init_decode_pages - Initialize an xdr_stream for decoding into pages |
f7da7a12 BH |
1318 | * @xdr: pointer to xdr_stream struct |
1319 | * @buf: pointer to XDR buffer from which to decode data | |
1320 | * @pages: list of pages to decode into | |
1321 | * @len: length in bytes of buffer in pages | |
1322 | */ | |
1323 | void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, | |
1324 | struct page **pages, unsigned int len) | |
1325 | { | |
1326 | memset(buf, 0, sizeof(*buf)); | |
1327 | buf->pages = pages; | |
1328 | buf->page_len = len; | |
1329 | buf->buflen = len; | |
1330 | buf->len = len; | |
0ccc61b1 | 1331 | xdr_init_decode(xdr, buf, NULL, NULL); |
f7da7a12 BH |
1332 | } |
1333 | EXPORT_SYMBOL_GPL(xdr_init_decode_pages); | |
1334 | ||
6650239a | 1335 | static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
ba8e452a | 1336 | { |
bfeea1dc | 1337 | unsigned int nwords = XDR_QUADLEN(nbytes); |
ba8e452a | 1338 | __be32 *p = xdr->p; |
bfeea1dc | 1339 | __be32 *q = p + nwords; |
ba8e452a | 1340 | |
bfeea1dc | 1341 | if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p)) |
ba8e452a | 1342 | return NULL; |
6650239a | 1343 | xdr->p = q; |
bfeea1dc | 1344 | xdr->nwords -= nwords; |
ba8e452a TM |
1345 | return p; |
1346 | } | |
ba8e452a | 1347 | |
6650239a TM |
1348 | static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes) |
1349 | { | |
1350 | __be32 *p; | |
ace0e14f | 1351 | char *cpdest = xdr->scratch.iov_base; |
6650239a TM |
1352 | size_t cplen = (char *)xdr->end - (char *)xdr->p; |
1353 | ||
1354 | if (nbytes > xdr->scratch.iov_len) | |
5582863f | 1355 | goto out_overflow; |
ace0e14f TM |
1356 | p = __xdr_inline_decode(xdr, cplen); |
1357 | if (p == NULL) | |
1358 | return NULL; | |
1359 | memcpy(cpdest, p, cplen); | |
5582863f CL |
1360 | if (!xdr_set_next_buffer(xdr)) |
1361 | goto out_overflow; | |
6650239a TM |
1362 | cpdest += cplen; |
1363 | nbytes -= cplen; | |
6650239a TM |
1364 | p = __xdr_inline_decode(xdr, nbytes); |
1365 | if (p == NULL) | |
1366 | return NULL; | |
1367 | memcpy(cpdest, p, nbytes); | |
1368 | return xdr->scratch.iov_base; | |
5582863f CL |
1369 | out_overflow: |
1370 | trace_rpc_xdr_overflow(xdr, nbytes); | |
1371 | return NULL; | |
6650239a TM |
1372 | } |
1373 | ||
1374 | /** | |
1375 | * xdr_inline_decode - Retrieve XDR data to decode | |
1da177e4 LT |
1376 | * @xdr: pointer to xdr_stream struct |
1377 | * @nbytes: number of bytes of data to decode | |
1378 | * | |
1379 | * Check if the input buffer is long enough to enable us to decode | |
1380 | * 'nbytes' more bytes of data starting at the current position. | |
1381 | * If so return the current pointer, then update the current | |
1382 | * pointer position. | |
1383 | */ | |
d8ed029d | 1384 | __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 1385 | { |
6650239a | 1386 | __be32 *p; |
1da177e4 | 1387 | |
5582863f | 1388 | if (unlikely(nbytes == 0)) |
6650239a TM |
1389 | return xdr->p; |
1390 | if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr)) | |
5582863f | 1391 | goto out_overflow; |
6650239a TM |
1392 | p = __xdr_inline_decode(xdr, nbytes); |
1393 | if (p != NULL) | |
1394 | return p; | |
1395 | return xdr_copy_to_scratch(xdr, nbytes); | |
5582863f CL |
1396 | out_overflow: |
1397 | trace_rpc_xdr_overflow(xdr, nbytes); | |
1398 | return NULL; | |
1da177e4 | 1399 | } |
468039ee | 1400 | EXPORT_SYMBOL_GPL(xdr_inline_decode); |
1da177e4 | 1401 | |
06216ecb | 1402 | static void xdr_realign_pages(struct xdr_stream *xdr) |
1da177e4 LT |
1403 | { |
1404 | struct xdr_buf *buf = xdr->buf; | |
06216ecb | 1405 | struct kvec *iov = buf->head; |
b760b313 | 1406 | unsigned int cur = xdr_stream_pos(xdr); |
6707fbd7 | 1407 | unsigned int copied; |
1da177e4 LT |
1408 | |
1409 | /* Realign pages to current pointer position */ | |
a11a2bf4 | 1410 | if (iov->iov_len > cur) { |
6707fbd7 TM |
1411 | copied = xdr_shrink_bufhead(buf, cur); |
1412 | trace_rpc_xdr_alignment(xdr, cur, copied); | |
5a5f1c2c | 1413 | xdr_set_page(xdr, 0, buf->page_len); |
a11a2bf4 | 1414 | } |
06216ecb AS |
1415 | } |
1416 | ||
1417 | static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len) | |
1418 | { | |
1419 | struct xdr_buf *buf = xdr->buf; | |
1420 | unsigned int nwords = XDR_QUADLEN(len); | |
c4f2f591 | 1421 | unsigned int copied; |
06216ecb AS |
1422 | |
1423 | if (xdr->nwords == 0) | |
1424 | return 0; | |
1da177e4 | 1425 | |
06216ecb | 1426 | xdr_realign_pages(xdr); |
a11a2bf4 TM |
1427 | if (nwords > xdr->nwords) { |
1428 | nwords = xdr->nwords; | |
1429 | len = nwords << 2; | |
1430 | } | |
1431 | if (buf->page_len <= len) | |
8a9a8b83 | 1432 | len = buf->page_len; |
a11a2bf4 TM |
1433 | else if (nwords < xdr->nwords) { |
1434 | /* Truncate page data and move it into the tail */ | |
c4f2f591 TM |
1435 | copied = xdr_shrink_pagelen(buf, len); |
1436 | trace_rpc_xdr_alignment(xdr, len, copied); | |
a11a2bf4 | 1437 | } |
3994ee6f TM |
1438 | return len; |
1439 | } | |
bd00f84b | 1440 | |
1da177e4 | 1441 | /** |
1d973166 | 1442 | * xdr_read_pages - align page-based XDR data to current pointer position |
1da177e4 LT |
1443 | * @xdr: pointer to xdr_stream struct |
1444 | * @len: number of bytes of page data | |
1445 | * | |
1446 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
1d973166 TM |
1447 | * into the page list. Any data that lies beyond current position + @len |
1448 | * bytes is moved into the XDR tail[]. The xdr_stream current position is | |
1449 | * then advanced past that data to align to the next XDR object in the tail. | |
3994ee6f TM |
1450 | * |
1451 | * Returns the number of XDR encoded bytes now contained in the pages | |
1da177e4 | 1452 | */ |
3994ee6f | 1453 | unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) |
1da177e4 | 1454 | { |
1d973166 TM |
1455 | unsigned int nwords = XDR_QUADLEN(len); |
1456 | unsigned int base, end, pglen; | |
1da177e4 | 1457 | |
1d973166 TM |
1458 | pglen = xdr_align_pages(xdr, nwords << 2); |
1459 | if (pglen == 0) | |
3994ee6f | 1460 | return 0; |
bd00f84b | 1461 | |
1d973166 TM |
1462 | base = (nwords << 2) - pglen; |
1463 | end = xdr_stream_remaining(xdr) - pglen; | |
1464 | ||
5a5f1c2c | 1465 | xdr_set_tail_base(xdr, base, end); |
1d973166 | 1466 | return len <= pglen ? len : pglen; |
1da177e4 | 1467 | } |
468039ee | 1468 | EXPORT_SYMBOL_GPL(xdr_read_pages); |
1da177e4 | 1469 | |
9a20f6f4 TM |
1470 | unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset, |
1471 | unsigned int length) | |
e6ac0acc AS |
1472 | { |
1473 | struct xdr_buf *buf = xdr->buf; | |
9a20f6f4 TM |
1474 | unsigned int from, bytes, len; |
1475 | unsigned int shift; | |
e6ac0acc AS |
1476 | |
1477 | xdr_realign_pages(xdr); | |
1478 | from = xdr_page_pos(xdr); | |
9a20f6f4 TM |
1479 | |
1480 | if (from >= buf->page_len + buf->tail->iov_len) | |
1481 | return 0; | |
1482 | if (from + buf->head->iov_len >= buf->len) | |
1483 | return 0; | |
1484 | ||
1485 | len = buf->len - buf->head->iov_len; | |
1486 | ||
1487 | /* We only shift data left! */ | |
1488 | if (WARN_ONCE(from < offset, "SUNRPC: misaligned data src=%u dst=%u\n", | |
1489 | from, offset)) | |
1490 | return 0; | |
1491 | if (WARN_ONCE(offset > buf->page_len, | |
1492 | "SUNRPC: buffer overflow. offset=%u, page_len=%u\n", | |
1493 | offset, buf->page_len)) | |
1494 | return 0; | |
e6ac0acc AS |
1495 | |
1496 | /* Move page data to the left */ | |
9a20f6f4 TM |
1497 | shift = from - offset; |
1498 | xdr_buf_pages_shift_left(buf, from, len, shift); | |
9a20f6f4 TM |
1499 | |
1500 | bytes = xdr_stream_remaining(xdr); | |
1501 | if (length > bytes) | |
1502 | length = bytes; | |
1503 | bytes -= length; | |
e6ac0acc | 1504 | |
5a5f1c2c | 1505 | xdr->buf->len -= shift; |
9a20f6f4 | 1506 | xdr_set_page(xdr, offset + length, bytes); |
e6ac0acc AS |
1507 | return length; |
1508 | } | |
1509 | EXPORT_SYMBOL_GPL(xdr_align_data); | |
1510 | ||
c4f2f591 TM |
1511 | unsigned int xdr_expand_hole(struct xdr_stream *xdr, unsigned int offset, |
1512 | unsigned int length) | |
84ce182a AS |
1513 | { |
1514 | struct xdr_buf *buf = xdr->buf; | |
c4f2f591 | 1515 | unsigned int from, to, shift; |
84ce182a AS |
1516 | |
1517 | xdr_realign_pages(xdr); | |
1518 | from = xdr_page_pos(xdr); | |
c4f2f591 TM |
1519 | to = xdr_align_size(offset + length); |
1520 | ||
1521 | /* Could the hole be behind us? */ | |
1522 | if (to > from) { | |
1523 | unsigned int buflen = buf->len - buf->head->iov_len; | |
1524 | shift = to - from; | |
1525 | xdr_buf_try_expand(buf, shift); | |
1526 | xdr_buf_pages_shift_right(buf, from, buflen, shift); | |
5a5f1c2c | 1527 | xdr_set_page(xdr, to, xdr_stream_remaining(xdr)); |
c4f2f591 TM |
1528 | } else if (to != from) |
1529 | xdr_align_data(xdr, to, 0); | |
1530 | xdr_buf_pages_zero(buf, offset, length); | |
84ce182a | 1531 | |
84ce182a AS |
1532 | return length; |
1533 | } | |
1534 | EXPORT_SYMBOL_GPL(xdr_expand_hole); | |
1535 | ||
8b23ea7b TM |
1536 | /** |
1537 | * xdr_enter_page - decode data from the XDR page | |
1538 | * @xdr: pointer to xdr_stream struct | |
1539 | * @len: number of bytes of page data | |
1540 | * | |
1541 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
1542 | * into the page list. Any data that lies beyond current position + "len" | |
1543 | * bytes is moved into the XDR tail[]. The current pointer is then | |
1544 | * repositioned at the beginning of the first XDR page. | |
1545 | */ | |
1546 | void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) | |
1547 | { | |
f8bb7f08 | 1548 | len = xdr_align_pages(xdr, len); |
8b23ea7b TM |
1549 | /* |
1550 | * Position current pointer at beginning of tail, and | |
1551 | * set remaining message length. | |
1552 | */ | |
f8bb7f08 TM |
1553 | if (len != 0) |
1554 | xdr_set_page_base(xdr, 0, len); | |
8b23ea7b | 1555 | } |
468039ee | 1556 | EXPORT_SYMBOL_GPL(xdr_enter_page); |
8b23ea7b | 1557 | |
c2bd2c0a | 1558 | static const struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0}; |
1da177e4 | 1559 | |
f8d0e60f | 1560 | void xdr_buf_from_iov(const struct kvec *iov, struct xdr_buf *buf) |
1da177e4 LT |
1561 | { |
1562 | buf->head[0] = *iov; | |
1563 | buf->tail[0] = empty_iov; | |
1564 | buf->page_len = 0; | |
1565 | buf->buflen = buf->len = iov->iov_len; | |
1566 | } | |
468039ee | 1567 | EXPORT_SYMBOL_GPL(xdr_buf_from_iov); |
1da177e4 | 1568 | |
de4aee2e BF |
1569 | /** |
1570 | * xdr_buf_subsegment - set subbuf to a portion of buf | |
1571 | * @buf: an xdr buffer | |
1572 | * @subbuf: the result buffer | |
1573 | * @base: beginning of range in bytes | |
1574 | * @len: length of range in bytes | |
1575 | * | |
1576 | * sets @subbuf to an xdr buffer representing the portion of @buf of | |
1577 | * length @len starting at offset @base. | |
1578 | * | |
1579 | * @buf and @subbuf may be pointers to the same struct xdr_buf. | |
1580 | * | |
1581 | * Returns -1 if base of length are out of bounds. | |
1582 | */ | |
5a7e7026 CL |
1583 | int xdr_buf_subsegment(const struct xdr_buf *buf, struct xdr_buf *subbuf, |
1584 | unsigned int base, unsigned int len) | |
1da177e4 | 1585 | { |
1da177e4 | 1586 | subbuf->buflen = subbuf->len = len; |
1e78957e TM |
1587 | if (base < buf->head[0].iov_len) { |
1588 | subbuf->head[0].iov_base = buf->head[0].iov_base + base; | |
1589 | subbuf->head[0].iov_len = min_t(unsigned int, len, | |
1590 | buf->head[0].iov_len - base); | |
1591 | len -= subbuf->head[0].iov_len; | |
1592 | base = 0; | |
1593 | } else { | |
1e78957e | 1594 | base -= buf->head[0].iov_len; |
89a3c9f5 | 1595 | subbuf->head[0].iov_base = buf->head[0].iov_base; |
de4aee2e | 1596 | subbuf->head[0].iov_len = 0; |
1e78957e | 1597 | } |
1da177e4 LT |
1598 | |
1599 | if (base < buf->page_len) { | |
1e78957e TM |
1600 | subbuf->page_len = min(buf->page_len - base, len); |
1601 | base += buf->page_base; | |
09cbfeaf KS |
1602 | subbuf->page_base = base & ~PAGE_MASK; |
1603 | subbuf->pages = &buf->pages[base >> PAGE_SHIFT]; | |
1da177e4 LT |
1604 | len -= subbuf->page_len; |
1605 | base = 0; | |
1606 | } else { | |
1607 | base -= buf->page_len; | |
89a3c9f5 CL |
1608 | subbuf->pages = buf->pages; |
1609 | subbuf->page_base = 0; | |
1da177e4 LT |
1610 | subbuf->page_len = 0; |
1611 | } | |
1612 | ||
1e78957e TM |
1613 | if (base < buf->tail[0].iov_len) { |
1614 | subbuf->tail[0].iov_base = buf->tail[0].iov_base + base; | |
1615 | subbuf->tail[0].iov_len = min_t(unsigned int, len, | |
1616 | buf->tail[0].iov_len - base); | |
1617 | len -= subbuf->tail[0].iov_len; | |
1618 | base = 0; | |
1619 | } else { | |
1e78957e | 1620 | base -= buf->tail[0].iov_len; |
89a3c9f5 | 1621 | subbuf->tail[0].iov_base = buf->tail[0].iov_base; |
de4aee2e | 1622 | subbuf->tail[0].iov_len = 0; |
1e78957e TM |
1623 | } |
1624 | ||
1da177e4 LT |
1625 | if (base || len) |
1626 | return -1; | |
1627 | return 0; | |
1628 | } | |
468039ee | 1629 | EXPORT_SYMBOL_GPL(xdr_buf_subsegment); |
1da177e4 | 1630 | |
c1346a12 CL |
1631 | /** |
1632 | * xdr_stream_subsegment - set @subbuf to a portion of @xdr | |
1633 | * @xdr: an xdr_stream set up for decoding | |
1634 | * @subbuf: the result buffer | |
1635 | * @nbytes: length of @xdr to extract, in bytes | |
1636 | * | |
1637 | * Sets up @subbuf to represent a portion of @xdr. The portion | |
1638 | * starts at the current offset in @xdr, and extends for a length | |
1639 | * of @nbytes. If this is successful, @xdr is advanced to the next | |
f49b68dd | 1640 | * XDR data item following that portion. |
c1346a12 CL |
1641 | * |
1642 | * Return values: | |
1643 | * %true: @subbuf has been initialized, and @xdr has been advanced. | |
1644 | * %false: a bounds error has occurred | |
1645 | */ | |
1646 | bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf, | |
1647 | unsigned int nbytes) | |
1648 | { | |
f49b68dd CL |
1649 | unsigned int start = xdr_stream_pos(xdr); |
1650 | unsigned int remaining, len; | |
c1346a12 | 1651 | |
f49b68dd CL |
1652 | /* Extract @subbuf and bounds-check the fn arguments */ |
1653 | if (xdr_buf_subsegment(xdr->buf, subbuf, start, nbytes)) | |
c1346a12 CL |
1654 | return false; |
1655 | ||
f49b68dd CL |
1656 | /* Advance @xdr by @nbytes */ |
1657 | for (remaining = nbytes; remaining;) { | |
c1346a12 CL |
1658 | if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr)) |
1659 | return false; | |
c1346a12 | 1660 | |
f49b68dd CL |
1661 | len = (char *)xdr->end - (char *)xdr->p; |
1662 | if (remaining <= len) { | |
1663 | xdr->p = (__be32 *)((char *)xdr->p + | |
1664 | (remaining + xdr_pad_size(nbytes))); | |
1665 | break; | |
1666 | } | |
1667 | ||
1668 | xdr->p = (__be32 *)((char *)xdr->p + len); | |
1669 | xdr->end = xdr->p; | |
c1346a12 | 1670 | remaining -= len; |
c1346a12 CL |
1671 | } |
1672 | ||
f49b68dd | 1673 | xdr_stream_set_pos(xdr, start + nbytes); |
c1346a12 CL |
1674 | return true; |
1675 | } | |
1676 | EXPORT_SYMBOL_GPL(xdr_stream_subsegment); | |
1677 | ||
0a8e7b7d CL |
1678 | /** |
1679 | * xdr_buf_trim - lop at most "len" bytes off the end of "buf" | |
1680 | * @buf: buf to be trimmed | |
1681 | * @len: number of bytes to reduce "buf" by | |
1682 | * | |
1683 | * Trim an xdr_buf by the given number of bytes by fixing up the lengths. Note | |
1684 | * that it's possible that we'll trim less than that amount if the xdr_buf is | |
1685 | * too small, or if (for instance) it's all in the head and the parser has | |
1686 | * already read too far into it. | |
1687 | */ | |
1688 | void xdr_buf_trim(struct xdr_buf *buf, unsigned int len) | |
1689 | { | |
1690 | size_t cur; | |
1691 | unsigned int trim = len; | |
1692 | ||
1693 | if (buf->tail[0].iov_len) { | |
1694 | cur = min_t(size_t, buf->tail[0].iov_len, trim); | |
1695 | buf->tail[0].iov_len -= cur; | |
1696 | trim -= cur; | |
1697 | if (!trim) | |
1698 | goto fix_len; | |
1699 | } | |
1700 | ||
1701 | if (buf->page_len) { | |
1702 | cur = min_t(unsigned int, buf->page_len, trim); | |
1703 | buf->page_len -= cur; | |
1704 | trim -= cur; | |
1705 | if (!trim) | |
1706 | goto fix_len; | |
1707 | } | |
1708 | ||
1709 | if (buf->head[0].iov_len) { | |
1710 | cur = min_t(size_t, buf->head[0].iov_len, trim); | |
1711 | buf->head[0].iov_len -= cur; | |
1712 | trim -= cur; | |
1713 | } | |
1714 | fix_len: | |
1715 | buf->len -= (len - trim); | |
1716 | } | |
1717 | EXPORT_SYMBOL_GPL(xdr_buf_trim); | |
1718 | ||
f8d0e60f TM |
1719 | static void __read_bytes_from_xdr_buf(const struct xdr_buf *subbuf, |
1720 | void *obj, unsigned int len) | |
1da177e4 | 1721 | { |
1e78957e | 1722 | unsigned int this_len; |
1da177e4 | 1723 | |
4e3e43ad TM |
1724 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
1725 | memcpy(obj, subbuf->head[0].iov_base, this_len); | |
1da177e4 LT |
1726 | len -= this_len; |
1727 | obj += this_len; | |
4e3e43ad | 1728 | this_len = min_t(unsigned int, len, subbuf->page_len); |
e43ac22b | 1729 | _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len); |
1da177e4 LT |
1730 | len -= this_len; |
1731 | obj += this_len; | |
4e3e43ad TM |
1732 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
1733 | memcpy(obj, subbuf->tail[0].iov_base, this_len); | |
1da177e4 LT |
1734 | } |
1735 | ||
bd8100e7 | 1736 | /* obj is assumed to point to allocated memory of size at least len: */ |
f8d0e60f TM |
1737 | int read_bytes_from_xdr_buf(const struct xdr_buf *buf, unsigned int base, |
1738 | void *obj, unsigned int len) | |
bd8100e7 AG |
1739 | { |
1740 | struct xdr_buf subbuf; | |
bd8100e7 AG |
1741 | int status; |
1742 | ||
1743 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
4e3e43ad TM |
1744 | if (status != 0) |
1745 | return status; | |
1746 | __read_bytes_from_xdr_buf(&subbuf, obj, len); | |
1747 | return 0; | |
1748 | } | |
468039ee | 1749 | EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf); |
4e3e43ad | 1750 | |
f8d0e60f TM |
1751 | static void __write_bytes_to_xdr_buf(const struct xdr_buf *subbuf, |
1752 | void *obj, unsigned int len) | |
4e3e43ad TM |
1753 | { |
1754 | unsigned int this_len; | |
1755 | ||
1756 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); | |
1757 | memcpy(subbuf->head[0].iov_base, obj, this_len); | |
bd8100e7 AG |
1758 | len -= this_len; |
1759 | obj += this_len; | |
4e3e43ad | 1760 | this_len = min_t(unsigned int, len, subbuf->page_len); |
e43ac22b | 1761 | _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len); |
bd8100e7 AG |
1762 | len -= this_len; |
1763 | obj += this_len; | |
4e3e43ad TM |
1764 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
1765 | memcpy(subbuf->tail[0].iov_base, obj, this_len); | |
1766 | } | |
1767 | ||
1768 | /* obj is assumed to point to allocated memory of size at least len: */ | |
f8d0e60f TM |
1769 | int write_bytes_to_xdr_buf(const struct xdr_buf *buf, unsigned int base, |
1770 | void *obj, unsigned int len) | |
4e3e43ad TM |
1771 | { |
1772 | struct xdr_buf subbuf; | |
1773 | int status; | |
1774 | ||
1775 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
1776 | if (status != 0) | |
1777 | return status; | |
1778 | __write_bytes_to_xdr_buf(&subbuf, obj, len); | |
1779 | return 0; | |
bd8100e7 | 1780 | } |
c43abaed | 1781 | EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf); |
bd8100e7 | 1782 | |
f8d0e60f | 1783 | int xdr_decode_word(const struct xdr_buf *buf, unsigned int base, u32 *obj) |
1da177e4 | 1784 | { |
d8ed029d | 1785 | __be32 raw; |
1da177e4 LT |
1786 | int status; |
1787 | ||
1788 | status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); | |
1789 | if (status) | |
1790 | return status; | |
98866b5a | 1791 | *obj = be32_to_cpu(raw); |
1da177e4 LT |
1792 | return 0; |
1793 | } | |
468039ee | 1794 | EXPORT_SYMBOL_GPL(xdr_decode_word); |
1da177e4 | 1795 | |
f8d0e60f | 1796 | int xdr_encode_word(const struct xdr_buf *buf, unsigned int base, u32 obj) |
bd8100e7 | 1797 | { |
9f162d2a | 1798 | __be32 raw = cpu_to_be32(obj); |
bd8100e7 AG |
1799 | |
1800 | return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj)); | |
1801 | } | |
468039ee | 1802 | EXPORT_SYMBOL_GPL(xdr_encode_word); |
bd8100e7 | 1803 | |
bd8100e7 | 1804 | /* Returns 0 on success, or else a negative error code. */ |
f8d0e60f TM |
1805 | static int xdr_xcode_array2(const struct xdr_buf *buf, unsigned int base, |
1806 | struct xdr_array2_desc *desc, int encode) | |
bd8100e7 AG |
1807 | { |
1808 | char *elem = NULL, *c; | |
1809 | unsigned int copied = 0, todo, avail_here; | |
1810 | struct page **ppages = NULL; | |
1811 | int err; | |
1812 | ||
1813 | if (encode) { | |
1814 | if (xdr_encode_word(buf, base, desc->array_len) != 0) | |
1815 | return -EINVAL; | |
1816 | } else { | |
1817 | if (xdr_decode_word(buf, base, &desc->array_len) != 0 || | |
58fcb8df | 1818 | desc->array_len > desc->array_maxlen || |
bd8100e7 AG |
1819 | (unsigned long) base + 4 + desc->array_len * |
1820 | desc->elem_size > buf->len) | |
1821 | return -EINVAL; | |
1822 | } | |
1823 | base += 4; | |
1824 | ||
1825 | if (!desc->xcode) | |
1826 | return 0; | |
1827 | ||
1828 | todo = desc->array_len * desc->elem_size; | |
1829 | ||
1830 | /* process head */ | |
1831 | if (todo && base < buf->head->iov_len) { | |
1832 | c = buf->head->iov_base + base; | |
1833 | avail_here = min_t(unsigned int, todo, | |
1834 | buf->head->iov_len - base); | |
1835 | todo -= avail_here; | |
1836 | ||
1837 | while (avail_here >= desc->elem_size) { | |
1838 | err = desc->xcode(desc, c); | |
1839 | if (err) | |
1840 | goto out; | |
1841 | c += desc->elem_size; | |
1842 | avail_here -= desc->elem_size; | |
1843 | } | |
1844 | if (avail_here) { | |
1845 | if (!elem) { | |
1846 | elem = kmalloc(desc->elem_size, GFP_KERNEL); | |
1847 | err = -ENOMEM; | |
1848 | if (!elem) | |
1849 | goto out; | |
1850 | } | |
1851 | if (encode) { | |
1852 | err = desc->xcode(desc, elem); | |
1853 | if (err) | |
1854 | goto out; | |
1855 | memcpy(c, elem, avail_here); | |
1856 | } else | |
1857 | memcpy(elem, c, avail_here); | |
1858 | copied = avail_here; | |
1859 | } | |
1860 | base = buf->head->iov_len; /* align to start of pages */ | |
1861 | } | |
1862 | ||
1863 | /* process pages array */ | |
1864 | base -= buf->head->iov_len; | |
1865 | if (todo && base < buf->page_len) { | |
1866 | unsigned int avail_page; | |
1867 | ||
1868 | avail_here = min(todo, buf->page_len - base); | |
1869 | todo -= avail_here; | |
1870 | ||
1871 | base += buf->page_base; | |
09cbfeaf KS |
1872 | ppages = buf->pages + (base >> PAGE_SHIFT); |
1873 | base &= ~PAGE_MASK; | |
1874 | avail_page = min_t(unsigned int, PAGE_SIZE - base, | |
bd8100e7 AG |
1875 | avail_here); |
1876 | c = kmap(*ppages) + base; | |
1877 | ||
1878 | while (avail_here) { | |
1879 | avail_here -= avail_page; | |
1880 | if (copied || avail_page < desc->elem_size) { | |
1881 | unsigned int l = min(avail_page, | |
1882 | desc->elem_size - copied); | |
1883 | if (!elem) { | |
1884 | elem = kmalloc(desc->elem_size, | |
1885 | GFP_KERNEL); | |
1886 | err = -ENOMEM; | |
1887 | if (!elem) | |
1888 | goto out; | |
1889 | } | |
1890 | if (encode) { | |
1891 | if (!copied) { | |
1892 | err = desc->xcode(desc, elem); | |
1893 | if (err) | |
1894 | goto out; | |
1895 | } | |
1896 | memcpy(c, elem + copied, l); | |
1897 | copied += l; | |
1898 | if (copied == desc->elem_size) | |
1899 | copied = 0; | |
1900 | } else { | |
1901 | memcpy(elem + copied, c, l); | |
1902 | copied += l; | |
1903 | if (copied == desc->elem_size) { | |
1904 | err = desc->xcode(desc, elem); | |
1905 | if (err) | |
1906 | goto out; | |
1907 | copied = 0; | |
1908 | } | |
1909 | } | |
1910 | avail_page -= l; | |
1911 | c += l; | |
1912 | } | |
1913 | while (avail_page >= desc->elem_size) { | |
1914 | err = desc->xcode(desc, c); | |
1915 | if (err) | |
1916 | goto out; | |
1917 | c += desc->elem_size; | |
1918 | avail_page -= desc->elem_size; | |
1919 | } | |
1920 | if (avail_page) { | |
1921 | unsigned int l = min(avail_page, | |
1922 | desc->elem_size - copied); | |
1923 | if (!elem) { | |
1924 | elem = kmalloc(desc->elem_size, | |
1925 | GFP_KERNEL); | |
1926 | err = -ENOMEM; | |
1927 | if (!elem) | |
1928 | goto out; | |
1929 | } | |
1930 | if (encode) { | |
1931 | if (!copied) { | |
1932 | err = desc->xcode(desc, elem); | |
1933 | if (err) | |
1934 | goto out; | |
1935 | } | |
1936 | memcpy(c, elem + copied, l); | |
1937 | copied += l; | |
1938 | if (copied == desc->elem_size) | |
1939 | copied = 0; | |
1940 | } else { | |
1941 | memcpy(elem + copied, c, l); | |
1942 | copied += l; | |
1943 | if (copied == desc->elem_size) { | |
1944 | err = desc->xcode(desc, elem); | |
1945 | if (err) | |
1946 | goto out; | |
1947 | copied = 0; | |
1948 | } | |
1949 | } | |
1950 | } | |
1951 | if (avail_here) { | |
1952 | kunmap(*ppages); | |
1953 | ppages++; | |
1954 | c = kmap(*ppages); | |
1955 | } | |
1956 | ||
1957 | avail_page = min(avail_here, | |
09cbfeaf | 1958 | (unsigned int) PAGE_SIZE); |
bd8100e7 AG |
1959 | } |
1960 | base = buf->page_len; /* align to start of tail */ | |
1961 | } | |
1962 | ||
1963 | /* process tail */ | |
1964 | base -= buf->page_len; | |
1965 | if (todo) { | |
1966 | c = buf->tail->iov_base + base; | |
1967 | if (copied) { | |
1968 | unsigned int l = desc->elem_size - copied; | |
1969 | ||
1970 | if (encode) | |
1971 | memcpy(c, elem + copied, l); | |
1972 | else { | |
1973 | memcpy(elem + copied, c, l); | |
1974 | err = desc->xcode(desc, elem); | |
1975 | if (err) | |
1976 | goto out; | |
1977 | } | |
1978 | todo -= l; | |
1979 | c += l; | |
1980 | } | |
1981 | while (todo) { | |
1982 | err = desc->xcode(desc, c); | |
1983 | if (err) | |
1984 | goto out; | |
1985 | c += desc->elem_size; | |
1986 | todo -= desc->elem_size; | |
1987 | } | |
1988 | } | |
1989 | err = 0; | |
1990 | ||
1991 | out: | |
a51482bd | 1992 | kfree(elem); |
bd8100e7 AG |
1993 | if (ppages) |
1994 | kunmap(*ppages); | |
1995 | return err; | |
1996 | } | |
1997 | ||
f8d0e60f TM |
1998 | int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base, |
1999 | struct xdr_array2_desc *desc) | |
bd8100e7 AG |
2000 | { |
2001 | if (base >= buf->len) | |
2002 | return -EINVAL; | |
2003 | ||
2004 | return xdr_xcode_array2(buf, base, desc, 0); | |
2005 | } | |
468039ee | 2006 | EXPORT_SYMBOL_GPL(xdr_decode_array2); |
bd8100e7 | 2007 | |
f8d0e60f TM |
2008 | int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base, |
2009 | struct xdr_array2_desc *desc) | |
bd8100e7 AG |
2010 | { |
2011 | if ((unsigned long) base + 4 + desc->array_len * desc->elem_size > | |
2012 | buf->head->iov_len + buf->page_len + buf->tail->iov_len) | |
2013 | return -EINVAL; | |
2014 | ||
2015 | return xdr_xcode_array2(buf, base, desc, 1); | |
2016 | } | |
468039ee | 2017 | EXPORT_SYMBOL_GPL(xdr_encode_array2); |
37a4e6cb | 2018 | |
f8d0e60f TM |
2019 | int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, |
2020 | unsigned int len, | |
2021 | int (*actor)(struct scatterlist *, void *), void *data) | |
37a4e6cb OK |
2022 | { |
2023 | int i, ret = 0; | |
95c96174 | 2024 | unsigned int page_len, thislen, page_offset; |
37a4e6cb OK |
2025 | struct scatterlist sg[1]; |
2026 | ||
68e3f5dd HX |
2027 | sg_init_table(sg, 1); |
2028 | ||
37a4e6cb OK |
2029 | if (offset >= buf->head[0].iov_len) { |
2030 | offset -= buf->head[0].iov_len; | |
2031 | } else { | |
2032 | thislen = buf->head[0].iov_len - offset; | |
2033 | if (thislen > len) | |
2034 | thislen = len; | |
2035 | sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); | |
2036 | ret = actor(sg, data); | |
2037 | if (ret) | |
2038 | goto out; | |
2039 | offset = 0; | |
2040 | len -= thislen; | |
2041 | } | |
2042 | if (len == 0) | |
2043 | goto out; | |
2044 | ||
2045 | if (offset >= buf->page_len) { | |
2046 | offset -= buf->page_len; | |
2047 | } else { | |
2048 | page_len = buf->page_len - offset; | |
2049 | if (page_len > len) | |
2050 | page_len = len; | |
2051 | len -= page_len; | |
09cbfeaf KS |
2052 | page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1); |
2053 | i = (offset + buf->page_base) >> PAGE_SHIFT; | |
2054 | thislen = PAGE_SIZE - page_offset; | |
37a4e6cb OK |
2055 | do { |
2056 | if (thislen > page_len) | |
2057 | thislen = page_len; | |
642f1490 | 2058 | sg_set_page(sg, buf->pages[i], thislen, page_offset); |
37a4e6cb OK |
2059 | ret = actor(sg, data); |
2060 | if (ret) | |
2061 | goto out; | |
2062 | page_len -= thislen; | |
2063 | i++; | |
2064 | page_offset = 0; | |
09cbfeaf | 2065 | thislen = PAGE_SIZE; |
37a4e6cb OK |
2066 | } while (page_len != 0); |
2067 | offset = 0; | |
2068 | } | |
2069 | if (len == 0) | |
2070 | goto out; | |
2071 | if (offset < buf->tail[0].iov_len) { | |
2072 | thislen = buf->tail[0].iov_len - offset; | |
2073 | if (thislen > len) | |
2074 | thislen = len; | |
2075 | sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); | |
2076 | ret = actor(sg, data); | |
2077 | len -= thislen; | |
2078 | } | |
2079 | if (len != 0) | |
2080 | ret = -EINVAL; | |
2081 | out: | |
2082 | return ret; | |
2083 | } | |
468039ee | 2084 | EXPORT_SYMBOL_GPL(xdr_process_buf); |
37a4e6cb | 2085 | |
0e779aa7 TM |
2086 | /** |
2087 | * xdr_stream_decode_opaque - Decode variable length opaque | |
2088 | * @xdr: pointer to xdr_stream | |
2089 | * @ptr: location to store opaque data | |
2090 | * @size: size of storage buffer @ptr | |
2091 | * | |
2092 | * Return values: | |
2093 | * On success, returns size of object stored in *@ptr | |
2094 | * %-EBADMSG on XDR buffer overflow | |
2095 | * %-EMSGSIZE on overflow of storage buffer @ptr | |
2096 | */ | |
2097 | ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size) | |
2098 | { | |
2099 | ssize_t ret; | |
2100 | void *p; | |
2101 | ||
2102 | ret = xdr_stream_decode_opaque_inline(xdr, &p, size); | |
2103 | if (ret <= 0) | |
2104 | return ret; | |
2105 | memcpy(ptr, p, ret); | |
2106 | return ret; | |
2107 | } | |
2108 | EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque); | |
2109 | ||
2110 | /** | |
2111 | * xdr_stream_decode_opaque_dup - Decode and duplicate variable length opaque | |
2112 | * @xdr: pointer to xdr_stream | |
2113 | * @ptr: location to store pointer to opaque data | |
2114 | * @maxlen: maximum acceptable object size | |
2115 | * @gfp_flags: GFP mask to use | |
2116 | * | |
2117 | * Return values: | |
2118 | * On success, returns size of object stored in *@ptr | |
2119 | * %-EBADMSG on XDR buffer overflow | |
2120 | * %-EMSGSIZE if the size of the object would exceed @maxlen | |
2121 | * %-ENOMEM on memory allocation failure | |
2122 | */ | |
2123 | ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, | |
2124 | size_t maxlen, gfp_t gfp_flags) | |
2125 | { | |
2126 | ssize_t ret; | |
2127 | void *p; | |
2128 | ||
2129 | ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); | |
2130 | if (ret > 0) { | |
2131 | *ptr = kmemdup(p, ret, gfp_flags); | |
2132 | if (*ptr != NULL) | |
2133 | return ret; | |
2134 | ret = -ENOMEM; | |
2135 | } | |
2136 | *ptr = NULL; | |
2137 | return ret; | |
2138 | } | |
2139 | EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup); | |
2140 | ||
2141 | /** | |
2142 | * xdr_stream_decode_string - Decode variable length string | |
2143 | * @xdr: pointer to xdr_stream | |
2144 | * @str: location to store string | |
2145 | * @size: size of storage buffer @str | |
2146 | * | |
2147 | * Return values: | |
2148 | * On success, returns length of NUL-terminated string stored in *@str | |
2149 | * %-EBADMSG on XDR buffer overflow | |
2150 | * %-EMSGSIZE on overflow of storage buffer @str | |
2151 | */ | |
2152 | ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size) | |
2153 | { | |
2154 | ssize_t ret; | |
2155 | void *p; | |
2156 | ||
2157 | ret = xdr_stream_decode_opaque_inline(xdr, &p, size); | |
2158 | if (ret > 0) { | |
2159 | memcpy(str, p, ret); | |
2160 | str[ret] = '\0'; | |
2161 | return strlen(str); | |
2162 | } | |
2163 | *str = '\0'; | |
2164 | return ret; | |
2165 | } | |
2166 | EXPORT_SYMBOL_GPL(xdr_stream_decode_string); | |
2167 | ||
5c741d4f TM |
2168 | /** |
2169 | * xdr_stream_decode_string_dup - Decode and duplicate variable length string | |
2170 | * @xdr: pointer to xdr_stream | |
2171 | * @str: location to store pointer to string | |
2172 | * @maxlen: maximum acceptable string length | |
2173 | * @gfp_flags: GFP mask to use | |
2174 | * | |
2175 | * Return values: | |
2176 | * On success, returns length of NUL-terminated string stored in *@ptr | |
2177 | * %-EBADMSG on XDR buffer overflow | |
2178 | * %-EMSGSIZE if the size of the string would exceed @maxlen | |
2179 | * %-ENOMEM on memory allocation failure | |
2180 | */ | |
2181 | ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, | |
2182 | size_t maxlen, gfp_t gfp_flags) | |
2183 | { | |
2184 | void *p; | |
2185 | ssize_t ret; | |
2186 | ||
2187 | ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); | |
2188 | if (ret > 0) { | |
4aceaaea | 2189 | char *s = kmemdup_nul(p, ret, gfp_flags); |
5c741d4f | 2190 | if (s != NULL) { |
5c741d4f TM |
2191 | *str = s; |
2192 | return strlen(s); | |
2193 | } | |
2194 | ret = -ENOMEM; | |
2195 | } | |
2196 | *str = NULL; | |
2197 | return ret; | |
2198 | } | |
2199 | EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup); |