Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/net/sunrpc/xdr.c | |
3 | * | |
4 | * Generic XDR support. | |
5 | * | |
6 | * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> | |
7 | */ | |
8 | ||
a246b010 | 9 | #include <linux/module.h> |
5a0e3ad6 | 10 | #include <linux/slab.h> |
1da177e4 | 11 | #include <linux/types.h> |
1da177e4 LT |
12 | #include <linux/string.h> |
13 | #include <linux/kernel.h> | |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/errno.h> | |
1da177e4 LT |
16 | #include <linux/sunrpc/xdr.h> |
17 | #include <linux/sunrpc/msg_prot.h> | |
18 | ||
19 | /* | |
20 | * XDR functions for basic NFS types | |
21 | */ | |
d8ed029d AD |
22 | __be32 * |
23 | xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj) | |
1da177e4 LT |
24 | { |
25 | unsigned int quadlen = XDR_QUADLEN(obj->len); | |
26 | ||
27 | p[quadlen] = 0; /* zero trailing bytes */ | |
9f162d2a | 28 | *p++ = cpu_to_be32(obj->len); |
1da177e4 LT |
29 | memcpy(p, obj->data, obj->len); |
30 | return p + XDR_QUADLEN(obj->len); | |
31 | } | |
468039ee | 32 | EXPORT_SYMBOL_GPL(xdr_encode_netobj); |
1da177e4 | 33 | |
d8ed029d AD |
34 | __be32 * |
35 | xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj) | |
1da177e4 LT |
36 | { |
37 | unsigned int len; | |
38 | ||
98866b5a | 39 | if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ) |
1da177e4 LT |
40 | return NULL; |
41 | obj->len = len; | |
42 | obj->data = (u8 *) p; | |
43 | return p + XDR_QUADLEN(len); | |
44 | } | |
468039ee | 45 | EXPORT_SYMBOL_GPL(xdr_decode_netobj); |
1da177e4 LT |
46 | |
47 | /** | |
48 | * xdr_encode_opaque_fixed - Encode fixed length opaque data | |
4dc3b16b PP |
49 | * @p: pointer to current position in XDR buffer. |
50 | * @ptr: pointer to data to encode (or NULL) | |
51 | * @nbytes: size of data. | |
1da177e4 LT |
52 | * |
53 | * Copy the array of data of length nbytes at ptr to the XDR buffer | |
54 | * at position p, then align to the next 32-bit boundary by padding | |
55 | * with zero bytes (see RFC1832). | |
56 | * Note: if ptr is NULL, only the padding is performed. | |
57 | * | |
58 | * Returns the updated current XDR buffer position | |
59 | * | |
60 | */ | |
d8ed029d | 61 | __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 LT |
62 | { |
63 | if (likely(nbytes != 0)) { | |
64 | unsigned int quadlen = XDR_QUADLEN(nbytes); | |
65 | unsigned int padding = (quadlen << 2) - nbytes; | |
66 | ||
67 | if (ptr != NULL) | |
68 | memcpy(p, ptr, nbytes); | |
69 | if (padding != 0) | |
70 | memset((char *)p + nbytes, 0, padding); | |
71 | p += quadlen; | |
72 | } | |
73 | return p; | |
74 | } | |
468039ee | 75 | EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed); |
1da177e4 LT |
76 | |
77 | /** | |
78 | * xdr_encode_opaque - Encode variable length opaque data | |
4dc3b16b PP |
79 | * @p: pointer to current position in XDR buffer. |
80 | * @ptr: pointer to data to encode (or NULL) | |
81 | * @nbytes: size of data. | |
1da177e4 LT |
82 | * |
83 | * Returns the updated current XDR buffer position | |
84 | */ | |
d8ed029d | 85 | __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 | 86 | { |
9f162d2a | 87 | *p++ = cpu_to_be32(nbytes); |
1da177e4 LT |
88 | return xdr_encode_opaque_fixed(p, ptr, nbytes); |
89 | } | |
468039ee | 90 | EXPORT_SYMBOL_GPL(xdr_encode_opaque); |
1da177e4 | 91 | |
d8ed029d AD |
92 | __be32 * |
93 | xdr_encode_string(__be32 *p, const char *string) | |
1da177e4 LT |
94 | { |
95 | return xdr_encode_array(p, string, strlen(string)); | |
96 | } | |
468039ee | 97 | EXPORT_SYMBOL_GPL(xdr_encode_string); |
1da177e4 | 98 | |
d8ed029d | 99 | __be32 * |
e5cff482 CL |
100 | xdr_decode_string_inplace(__be32 *p, char **sp, |
101 | unsigned int *lenp, unsigned int maxlen) | |
1da177e4 | 102 | { |
e5cff482 | 103 | u32 len; |
1da177e4 | 104 | |
98866b5a | 105 | len = be32_to_cpu(*p++); |
e5cff482 | 106 | if (len > maxlen) |
1da177e4 LT |
107 | return NULL; |
108 | *lenp = len; | |
109 | *sp = (char *) p; | |
110 | return p + XDR_QUADLEN(len); | |
111 | } | |
468039ee | 112 | EXPORT_SYMBOL_GPL(xdr_decode_string_inplace); |
1da177e4 LT |
113 | |
114 | void | |
115 | xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base, | |
116 | unsigned int len) | |
117 | { | |
118 | struct kvec *tail = xdr->tail; | |
119 | u32 *p; | |
120 | ||
121 | xdr->pages = pages; | |
122 | xdr->page_base = base; | |
123 | xdr->page_len = len; | |
124 | ||
125 | p = (u32 *)xdr->head[0].iov_base + XDR_QUADLEN(xdr->head[0].iov_len); | |
126 | tail->iov_base = p; | |
127 | tail->iov_len = 0; | |
128 | ||
129 | if (len & 3) { | |
130 | unsigned int pad = 4 - (len & 3); | |
131 | ||
132 | *p = 0; | |
133 | tail->iov_base = (char *)p + (len & 3); | |
134 | tail->iov_len = pad; | |
135 | len += pad; | |
136 | } | |
137 | xdr->buflen += len; | |
138 | xdr->len += len; | |
139 | } | |
468039ee | 140 | EXPORT_SYMBOL_GPL(xdr_encode_pages); |
1da177e4 LT |
141 | |
142 | void | |
143 | xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, | |
144 | struct page **pages, unsigned int base, unsigned int len) | |
145 | { | |
146 | struct kvec *head = xdr->head; | |
147 | struct kvec *tail = xdr->tail; | |
148 | char *buf = (char *)head->iov_base; | |
149 | unsigned int buflen = head->iov_len; | |
150 | ||
151 | head->iov_len = offset; | |
152 | ||
153 | xdr->pages = pages; | |
154 | xdr->page_base = base; | |
155 | xdr->page_len = len; | |
156 | ||
157 | tail->iov_base = buf + offset; | |
158 | tail->iov_len = buflen - offset; | |
159 | ||
160 | xdr->buflen += len; | |
161 | } | |
468039ee | 162 | EXPORT_SYMBOL_GPL(xdr_inline_pages); |
1da177e4 | 163 | |
1da177e4 LT |
164 | /* |
165 | * Helper routines for doing 'memmove' like operations on a struct xdr_buf | |
166 | * | |
167 | * _shift_data_right_pages | |
168 | * @pages: vector of pages containing both the source and dest memory area. | |
169 | * @pgto_base: page vector address of destination | |
170 | * @pgfrom_base: page vector address of source | |
171 | * @len: number of bytes to copy | |
172 | * | |
173 | * Note: the addresses pgto_base and pgfrom_base are both calculated in | |
174 | * the same way: | |
175 | * if a memory area starts at byte 'base' in page 'pages[i]', | |
176 | * then its address is given as (i << PAGE_CACHE_SHIFT) + base | |
177 | * Also note: pgfrom_base must be < pgto_base, but the memory areas | |
178 | * they point to may overlap. | |
179 | */ | |
180 | static void | |
181 | _shift_data_right_pages(struct page **pages, size_t pgto_base, | |
182 | size_t pgfrom_base, size_t len) | |
183 | { | |
184 | struct page **pgfrom, **pgto; | |
185 | char *vfrom, *vto; | |
186 | size_t copy; | |
187 | ||
188 | BUG_ON(pgto_base <= pgfrom_base); | |
189 | ||
190 | pgto_base += len; | |
191 | pgfrom_base += len; | |
192 | ||
193 | pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT); | |
194 | pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT); | |
195 | ||
196 | pgto_base &= ~PAGE_CACHE_MASK; | |
197 | pgfrom_base &= ~PAGE_CACHE_MASK; | |
198 | ||
199 | do { | |
200 | /* Are any pointers crossing a page boundary? */ | |
201 | if (pgto_base == 0) { | |
1da177e4 LT |
202 | pgto_base = PAGE_CACHE_SIZE; |
203 | pgto--; | |
204 | } | |
205 | if (pgfrom_base == 0) { | |
206 | pgfrom_base = PAGE_CACHE_SIZE; | |
207 | pgfrom--; | |
208 | } | |
209 | ||
210 | copy = len; | |
211 | if (copy > pgto_base) | |
212 | copy = pgto_base; | |
213 | if (copy > pgfrom_base) | |
214 | copy = pgfrom_base; | |
215 | pgto_base -= copy; | |
216 | pgfrom_base -= copy; | |
217 | ||
218 | vto = kmap_atomic(*pgto, KM_USER0); | |
219 | vfrom = kmap_atomic(*pgfrom, KM_USER1); | |
220 | memmove(vto + pgto_base, vfrom + pgfrom_base, copy); | |
bce3481c | 221 | flush_dcache_page(*pgto); |
1da177e4 LT |
222 | kunmap_atomic(vfrom, KM_USER1); |
223 | kunmap_atomic(vto, KM_USER0); | |
224 | ||
225 | } while ((len -= copy) != 0); | |
1da177e4 LT |
226 | } |
227 | ||
228 | /* | |
229 | * _copy_to_pages | |
230 | * @pages: array of pages | |
231 | * @pgbase: page vector address of destination | |
232 | * @p: pointer to source data | |
233 | * @len: length | |
234 | * | |
235 | * Copies data from an arbitrary memory location into an array of pages | |
236 | * The copy is assumed to be non-overlapping. | |
237 | */ | |
238 | static void | |
239 | _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len) | |
240 | { | |
241 | struct page **pgto; | |
242 | char *vto; | |
243 | size_t copy; | |
244 | ||
245 | pgto = pages + (pgbase >> PAGE_CACHE_SHIFT); | |
246 | pgbase &= ~PAGE_CACHE_MASK; | |
247 | ||
daeba89d | 248 | for (;;) { |
1da177e4 LT |
249 | copy = PAGE_CACHE_SIZE - pgbase; |
250 | if (copy > len) | |
251 | copy = len; | |
252 | ||
253 | vto = kmap_atomic(*pgto, KM_USER0); | |
254 | memcpy(vto + pgbase, p, copy); | |
255 | kunmap_atomic(vto, KM_USER0); | |
256 | ||
daeba89d TM |
257 | len -= copy; |
258 | if (len == 0) | |
259 | break; | |
260 | ||
1da177e4 LT |
261 | pgbase += copy; |
262 | if (pgbase == PAGE_CACHE_SIZE) { | |
263 | flush_dcache_page(*pgto); | |
264 | pgbase = 0; | |
265 | pgto++; | |
266 | } | |
267 | p += copy; | |
daeba89d | 268 | } |
1da177e4 LT |
269 | flush_dcache_page(*pgto); |
270 | } | |
271 | ||
272 | /* | |
273 | * _copy_from_pages | |
274 | * @p: pointer to destination | |
275 | * @pages: array of pages | |
276 | * @pgbase: offset of source data | |
277 | * @len: length | |
278 | * | |
279 | * Copies data into an arbitrary memory location from an array of pages | |
280 | * The copy is assumed to be non-overlapping. | |
281 | */ | |
282 | static void | |
283 | _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) | |
284 | { | |
285 | struct page **pgfrom; | |
286 | char *vfrom; | |
287 | size_t copy; | |
288 | ||
289 | pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT); | |
290 | pgbase &= ~PAGE_CACHE_MASK; | |
291 | ||
292 | do { | |
293 | copy = PAGE_CACHE_SIZE - pgbase; | |
294 | if (copy > len) | |
295 | copy = len; | |
296 | ||
297 | vfrom = kmap_atomic(*pgfrom, KM_USER0); | |
298 | memcpy(p, vfrom + pgbase, copy); | |
299 | kunmap_atomic(vfrom, KM_USER0); | |
300 | ||
301 | pgbase += copy; | |
302 | if (pgbase == PAGE_CACHE_SIZE) { | |
303 | pgbase = 0; | |
304 | pgfrom++; | |
305 | } | |
306 | p += copy; | |
307 | ||
308 | } while ((len -= copy) != 0); | |
309 | } | |
310 | ||
311 | /* | |
312 | * xdr_shrink_bufhead | |
313 | * @buf: xdr_buf | |
314 | * @len: bytes to remove from buf->head[0] | |
315 | * | |
cca5172a | 316 | * Shrinks XDR buffer's header kvec buf->head[0] by |
1da177e4 LT |
317 | * 'len' bytes. The extra data is not lost, but is instead |
318 | * moved into the inlined pages and/or the tail. | |
319 | */ | |
320 | static void | |
321 | xdr_shrink_bufhead(struct xdr_buf *buf, size_t len) | |
322 | { | |
323 | struct kvec *head, *tail; | |
324 | size_t copy, offs; | |
325 | unsigned int pglen = buf->page_len; | |
326 | ||
327 | tail = buf->tail; | |
328 | head = buf->head; | |
329 | BUG_ON (len > head->iov_len); | |
330 | ||
331 | /* Shift the tail first */ | |
332 | if (tail->iov_len != 0) { | |
333 | if (tail->iov_len > len) { | |
334 | copy = tail->iov_len - len; | |
335 | memmove((char *)tail->iov_base + len, | |
336 | tail->iov_base, copy); | |
337 | } | |
338 | /* Copy from the inlined pages into the tail */ | |
339 | copy = len; | |
340 | if (copy > pglen) | |
341 | copy = pglen; | |
342 | offs = len - copy; | |
343 | if (offs >= tail->iov_len) | |
344 | copy = 0; | |
345 | else if (copy > tail->iov_len - offs) | |
346 | copy = tail->iov_len - offs; | |
347 | if (copy != 0) | |
348 | _copy_from_pages((char *)tail->iov_base + offs, | |
349 | buf->pages, | |
350 | buf->page_base + pglen + offs - len, | |
351 | copy); | |
352 | /* Do we also need to copy data from the head into the tail ? */ | |
353 | if (len > pglen) { | |
354 | offs = copy = len - pglen; | |
355 | if (copy > tail->iov_len) | |
356 | copy = tail->iov_len; | |
357 | memcpy(tail->iov_base, | |
358 | (char *)head->iov_base + | |
359 | head->iov_len - offs, | |
360 | copy); | |
361 | } | |
362 | } | |
363 | /* Now handle pages */ | |
364 | if (pglen != 0) { | |
365 | if (pglen > len) | |
366 | _shift_data_right_pages(buf->pages, | |
367 | buf->page_base + len, | |
368 | buf->page_base, | |
369 | pglen - len); | |
370 | copy = len; | |
371 | if (len > pglen) | |
372 | copy = pglen; | |
373 | _copy_to_pages(buf->pages, buf->page_base, | |
374 | (char *)head->iov_base + head->iov_len - len, | |
375 | copy); | |
376 | } | |
377 | head->iov_len -= len; | |
378 | buf->buflen -= len; | |
379 | /* Have we truncated the message? */ | |
380 | if (buf->len > buf->buflen) | |
381 | buf->len = buf->buflen; | |
382 | } | |
383 | ||
384 | /* | |
385 | * xdr_shrink_pagelen | |
386 | * @buf: xdr_buf | |
387 | * @len: bytes to remove from buf->pages | |
388 | * | |
cca5172a | 389 | * Shrinks XDR buffer's page array buf->pages by |
1da177e4 LT |
390 | * 'len' bytes. The extra data is not lost, but is instead |
391 | * moved into the tail. | |
392 | */ | |
393 | static void | |
394 | xdr_shrink_pagelen(struct xdr_buf *buf, size_t len) | |
395 | { | |
396 | struct kvec *tail; | |
397 | size_t copy; | |
1da177e4 LT |
398 | unsigned int pglen = buf->page_len; |
399 | ||
400 | tail = buf->tail; | |
401 | BUG_ON (len > pglen); | |
402 | ||
403 | /* Shift the tail first */ | |
404 | if (tail->iov_len != 0) { | |
1da177e4 | 405 | if (tail->iov_len > len) { |
0fe62a35 | 406 | char *p = (char *)tail->iov_base + len; |
1da177e4 LT |
407 | copy = tail->iov_len - len; |
408 | memmove(p, tail->iov_base, copy); | |
b1a7a91a | 409 | } |
1da177e4 LT |
410 | /* Copy from the inlined pages into the tail */ |
411 | copy = len; | |
412 | if (copy > tail->iov_len) | |
413 | copy = tail->iov_len; | |
414 | _copy_from_pages((char *)tail->iov_base, | |
415 | buf->pages, buf->page_base + pglen - len, | |
416 | copy); | |
417 | } | |
418 | buf->page_len -= len; | |
419 | buf->buflen -= len; | |
420 | /* Have we truncated the message? */ | |
421 | if (buf->len > buf->buflen) | |
422 | buf->len = buf->buflen; | |
423 | } | |
424 | ||
425 | void | |
426 | xdr_shift_buf(struct xdr_buf *buf, size_t len) | |
427 | { | |
428 | xdr_shrink_bufhead(buf, len); | |
429 | } | |
468039ee | 430 | EXPORT_SYMBOL_GPL(xdr_shift_buf); |
1da177e4 LT |
431 | |
432 | /** | |
433 | * xdr_init_encode - Initialize a struct xdr_stream for sending data. | |
434 | * @xdr: pointer to xdr_stream struct | |
435 | * @buf: pointer to XDR buffer in which to encode data | |
436 | * @p: current pointer inside XDR buffer | |
437 | * | |
438 | * Note: at the moment the RPC client only passes the length of our | |
439 | * scratch buffer in the xdr_buf's header kvec. Previously this | |
440 | * meant we needed to call xdr_adjust_iovec() after encoding the | |
441 | * data. With the new scheme, the xdr_stream manages the details | |
442 | * of the buffer length, and takes care of adjusting the kvec | |
443 | * length for us. | |
444 | */ | |
d8ed029d | 445 | void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p) |
1da177e4 LT |
446 | { |
447 | struct kvec *iov = buf->head; | |
334ccfd5 | 448 | int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len; |
1da177e4 | 449 | |
334ccfd5 | 450 | BUG_ON(scratch_len < 0); |
1da177e4 LT |
451 | xdr->buf = buf; |
452 | xdr->iov = iov; | |
d8ed029d AD |
453 | xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len); |
454 | xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len); | |
334ccfd5 TM |
455 | BUG_ON(iov->iov_len > scratch_len); |
456 | ||
457 | if (p != xdr->p && p != NULL) { | |
458 | size_t len; | |
459 | ||
460 | BUG_ON(p < xdr->p || p > xdr->end); | |
461 | len = (char *)p - (char *)xdr->p; | |
462 | xdr->p = p; | |
463 | buf->len += len; | |
464 | iov->iov_len += len; | |
465 | } | |
1da177e4 | 466 | } |
468039ee | 467 | EXPORT_SYMBOL_GPL(xdr_init_encode); |
1da177e4 LT |
468 | |
469 | /** | |
470 | * xdr_reserve_space - Reserve buffer space for sending | |
471 | * @xdr: pointer to xdr_stream | |
472 | * @nbytes: number of bytes to reserve | |
473 | * | |
474 | * Checks that we have enough buffer space to encode 'nbytes' more | |
475 | * bytes of data. If so, update the total xdr_buf length, and | |
476 | * adjust the length of the current kvec. | |
477 | */ | |
d8ed029d | 478 | __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 479 | { |
d8ed029d AD |
480 | __be32 *p = xdr->p; |
481 | __be32 *q; | |
1da177e4 LT |
482 | |
483 | /* align nbytes on the next 32-bit boundary */ | |
484 | nbytes += 3; | |
485 | nbytes &= ~3; | |
486 | q = p + (nbytes >> 2); | |
487 | if (unlikely(q > xdr->end || q < p)) | |
488 | return NULL; | |
489 | xdr->p = q; | |
490 | xdr->iov->iov_len += nbytes; | |
491 | xdr->buf->len += nbytes; | |
492 | return p; | |
493 | } | |
468039ee | 494 | EXPORT_SYMBOL_GPL(xdr_reserve_space); |
1da177e4 LT |
495 | |
496 | /** | |
497 | * xdr_write_pages - Insert a list of pages into an XDR buffer for sending | |
498 | * @xdr: pointer to xdr_stream | |
499 | * @pages: list of pages | |
500 | * @base: offset of first byte | |
501 | * @len: length of data in bytes | |
502 | * | |
503 | */ | |
504 | void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, | |
505 | unsigned int len) | |
506 | { | |
507 | struct xdr_buf *buf = xdr->buf; | |
508 | struct kvec *iov = buf->tail; | |
509 | buf->pages = pages; | |
510 | buf->page_base = base; | |
511 | buf->page_len = len; | |
512 | ||
513 | iov->iov_base = (char *)xdr->p; | |
514 | iov->iov_len = 0; | |
515 | xdr->iov = iov; | |
516 | ||
517 | if (len & 3) { | |
518 | unsigned int pad = 4 - (len & 3); | |
519 | ||
520 | BUG_ON(xdr->p >= xdr->end); | |
521 | iov->iov_base = (char *)xdr->p + (len & 3); | |
522 | iov->iov_len += pad; | |
523 | len += pad; | |
524 | *xdr->p++ = 0; | |
525 | } | |
526 | buf->buflen += len; | |
527 | buf->len += len; | |
528 | } | |
468039ee | 529 | EXPORT_SYMBOL_GPL(xdr_write_pages); |
1da177e4 LT |
530 | |
531 | /** | |
532 | * xdr_init_decode - Initialize an xdr_stream for decoding data. | |
533 | * @xdr: pointer to xdr_stream struct | |
534 | * @buf: pointer to XDR buffer from which to decode data | |
535 | * @p: current pointer inside XDR buffer | |
536 | */ | |
d8ed029d | 537 | void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p) |
1da177e4 LT |
538 | { |
539 | struct kvec *iov = buf->head; | |
540 | unsigned int len = iov->iov_len; | |
541 | ||
542 | if (len > buf->len) | |
543 | len = buf->len; | |
544 | xdr->buf = buf; | |
545 | xdr->iov = iov; | |
546 | xdr->p = p; | |
d8ed029d | 547 | xdr->end = (__be32 *)((char *)iov->iov_base + len); |
1da177e4 | 548 | } |
468039ee | 549 | EXPORT_SYMBOL_GPL(xdr_init_decode); |
1da177e4 LT |
550 | |
551 | /** | |
552 | * xdr_inline_decode - Retrieve non-page XDR data to decode | |
553 | * @xdr: pointer to xdr_stream struct | |
554 | * @nbytes: number of bytes of data to decode | |
555 | * | |
556 | * Check if the input buffer is long enough to enable us to decode | |
557 | * 'nbytes' more bytes of data starting at the current position. | |
558 | * If so return the current pointer, then update the current | |
559 | * pointer position. | |
560 | */ | |
d8ed029d | 561 | __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 562 | { |
d8ed029d AD |
563 | __be32 *p = xdr->p; |
564 | __be32 *q = p + XDR_QUADLEN(nbytes); | |
1da177e4 LT |
565 | |
566 | if (unlikely(q > xdr->end || q < p)) | |
567 | return NULL; | |
568 | xdr->p = q; | |
569 | return p; | |
570 | } | |
468039ee | 571 | EXPORT_SYMBOL_GPL(xdr_inline_decode); |
1da177e4 LT |
572 | |
573 | /** | |
574 | * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position | |
575 | * @xdr: pointer to xdr_stream struct | |
576 | * @len: number of bytes of page data | |
577 | * | |
578 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
579 | * into the page list. Any data that lies beyond current position + "len" | |
8b23ea7b | 580 | * bytes is moved into the XDR tail[]. |
1da177e4 LT |
581 | */ |
582 | void xdr_read_pages(struct xdr_stream *xdr, unsigned int len) | |
583 | { | |
584 | struct xdr_buf *buf = xdr->buf; | |
585 | struct kvec *iov; | |
586 | ssize_t shift; | |
587 | unsigned int end; | |
588 | int padding; | |
589 | ||
590 | /* Realign pages to current pointer position */ | |
591 | iov = buf->head; | |
592 | shift = iov->iov_len + (char *)iov->iov_base - (char *)xdr->p; | |
593 | if (shift > 0) | |
594 | xdr_shrink_bufhead(buf, shift); | |
595 | ||
596 | /* Truncate page data and move it into the tail */ | |
597 | if (buf->page_len > len) | |
598 | xdr_shrink_pagelen(buf, buf->page_len - len); | |
599 | padding = (XDR_QUADLEN(len) << 2) - len; | |
600 | xdr->iov = iov = buf->tail; | |
601 | /* Compute remaining message length. */ | |
602 | end = iov->iov_len; | |
603 | shift = buf->buflen - buf->len; | |
604 | if (shift < end) | |
605 | end -= shift; | |
606 | else if (shift > 0) | |
607 | end = 0; | |
608 | /* | |
609 | * Position current pointer at beginning of tail, and | |
610 | * set remaining message length. | |
611 | */ | |
d8ed029d AD |
612 | xdr->p = (__be32 *)((char *)iov->iov_base + padding); |
613 | xdr->end = (__be32 *)((char *)iov->iov_base + end); | |
1da177e4 | 614 | } |
468039ee | 615 | EXPORT_SYMBOL_GPL(xdr_read_pages); |
1da177e4 | 616 | |
8b23ea7b TM |
617 | /** |
618 | * xdr_enter_page - decode data from the XDR page | |
619 | * @xdr: pointer to xdr_stream struct | |
620 | * @len: number of bytes of page data | |
621 | * | |
622 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
623 | * into the page list. Any data that lies beyond current position + "len" | |
624 | * bytes is moved into the XDR tail[]. The current pointer is then | |
625 | * repositioned at the beginning of the first XDR page. | |
626 | */ | |
627 | void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) | |
628 | { | |
629 | char * kaddr = page_address(xdr->buf->pages[0]); | |
630 | xdr_read_pages(xdr, len); | |
631 | /* | |
632 | * Position current pointer at beginning of tail, and | |
633 | * set remaining message length. | |
634 | */ | |
635 | if (len > PAGE_CACHE_SIZE - xdr->buf->page_base) | |
636 | len = PAGE_CACHE_SIZE - xdr->buf->page_base; | |
d8ed029d AD |
637 | xdr->p = (__be32 *)(kaddr + xdr->buf->page_base); |
638 | xdr->end = (__be32 *)((char *)xdr->p + len); | |
8b23ea7b | 639 | } |
468039ee | 640 | EXPORT_SYMBOL_GPL(xdr_enter_page); |
8b23ea7b | 641 | |
1da177e4 LT |
642 | static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0}; |
643 | ||
644 | void | |
645 | xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf) | |
646 | { | |
647 | buf->head[0] = *iov; | |
648 | buf->tail[0] = empty_iov; | |
649 | buf->page_len = 0; | |
650 | buf->buflen = buf->len = iov->iov_len; | |
651 | } | |
468039ee | 652 | EXPORT_SYMBOL_GPL(xdr_buf_from_iov); |
1da177e4 | 653 | |
1da177e4 LT |
654 | /* Sets subbuf to the portion of buf of length len beginning base bytes |
655 | * from the start of buf. Returns -1 if base of length are out of bounds. */ | |
656 | int | |
657 | xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, | |
1e78957e | 658 | unsigned int base, unsigned int len) |
1da177e4 | 659 | { |
1da177e4 | 660 | subbuf->buflen = subbuf->len = len; |
1e78957e TM |
661 | if (base < buf->head[0].iov_len) { |
662 | subbuf->head[0].iov_base = buf->head[0].iov_base + base; | |
663 | subbuf->head[0].iov_len = min_t(unsigned int, len, | |
664 | buf->head[0].iov_len - base); | |
665 | len -= subbuf->head[0].iov_len; | |
666 | base = 0; | |
667 | } else { | |
668 | subbuf->head[0].iov_base = NULL; | |
669 | subbuf->head[0].iov_len = 0; | |
670 | base -= buf->head[0].iov_len; | |
671 | } | |
1da177e4 LT |
672 | |
673 | if (base < buf->page_len) { | |
1e78957e TM |
674 | subbuf->page_len = min(buf->page_len - base, len); |
675 | base += buf->page_base; | |
676 | subbuf->page_base = base & ~PAGE_CACHE_MASK; | |
677 | subbuf->pages = &buf->pages[base >> PAGE_CACHE_SHIFT]; | |
1da177e4 LT |
678 | len -= subbuf->page_len; |
679 | base = 0; | |
680 | } else { | |
681 | base -= buf->page_len; | |
682 | subbuf->page_len = 0; | |
683 | } | |
684 | ||
1e78957e TM |
685 | if (base < buf->tail[0].iov_len) { |
686 | subbuf->tail[0].iov_base = buf->tail[0].iov_base + base; | |
687 | subbuf->tail[0].iov_len = min_t(unsigned int, len, | |
688 | buf->tail[0].iov_len - base); | |
689 | len -= subbuf->tail[0].iov_len; | |
690 | base = 0; | |
691 | } else { | |
692 | subbuf->tail[0].iov_base = NULL; | |
693 | subbuf->tail[0].iov_len = 0; | |
694 | base -= buf->tail[0].iov_len; | |
695 | } | |
696 | ||
1da177e4 LT |
697 | if (base || len) |
698 | return -1; | |
699 | return 0; | |
700 | } | |
468039ee | 701 | EXPORT_SYMBOL_GPL(xdr_buf_subsegment); |
1da177e4 | 702 | |
4e3e43ad | 703 | static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) |
1da177e4 | 704 | { |
1e78957e | 705 | unsigned int this_len; |
1da177e4 | 706 | |
4e3e43ad TM |
707 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
708 | memcpy(obj, subbuf->head[0].iov_base, this_len); | |
1da177e4 LT |
709 | len -= this_len; |
710 | obj += this_len; | |
4e3e43ad | 711 | this_len = min_t(unsigned int, len, subbuf->page_len); |
1da177e4 | 712 | if (this_len) |
4e3e43ad | 713 | _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len); |
1da177e4 LT |
714 | len -= this_len; |
715 | obj += this_len; | |
4e3e43ad TM |
716 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
717 | memcpy(obj, subbuf->tail[0].iov_base, this_len); | |
1da177e4 LT |
718 | } |
719 | ||
bd8100e7 | 720 | /* obj is assumed to point to allocated memory of size at least len: */ |
4e3e43ad | 721 | int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) |
bd8100e7 AG |
722 | { |
723 | struct xdr_buf subbuf; | |
bd8100e7 AG |
724 | int status; |
725 | ||
726 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
4e3e43ad TM |
727 | if (status != 0) |
728 | return status; | |
729 | __read_bytes_from_xdr_buf(&subbuf, obj, len); | |
730 | return 0; | |
731 | } | |
468039ee | 732 | EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf); |
4e3e43ad TM |
733 | |
734 | static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) | |
735 | { | |
736 | unsigned int this_len; | |
737 | ||
738 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); | |
739 | memcpy(subbuf->head[0].iov_base, obj, this_len); | |
bd8100e7 AG |
740 | len -= this_len; |
741 | obj += this_len; | |
4e3e43ad | 742 | this_len = min_t(unsigned int, len, subbuf->page_len); |
bd8100e7 | 743 | if (this_len) |
4e3e43ad | 744 | _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len); |
bd8100e7 AG |
745 | len -= this_len; |
746 | obj += this_len; | |
4e3e43ad TM |
747 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
748 | memcpy(subbuf->tail[0].iov_base, obj, this_len); | |
749 | } | |
750 | ||
751 | /* obj is assumed to point to allocated memory of size at least len: */ | |
752 | int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) | |
753 | { | |
754 | struct xdr_buf subbuf; | |
755 | int status; | |
756 | ||
757 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
758 | if (status != 0) | |
759 | return status; | |
760 | __write_bytes_to_xdr_buf(&subbuf, obj, len); | |
761 | return 0; | |
bd8100e7 | 762 | } |
c43abaed | 763 | EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf); |
bd8100e7 AG |
764 | |
765 | int | |
1e78957e | 766 | xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj) |
1da177e4 | 767 | { |
d8ed029d | 768 | __be32 raw; |
1da177e4 LT |
769 | int status; |
770 | ||
771 | status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); | |
772 | if (status) | |
773 | return status; | |
98866b5a | 774 | *obj = be32_to_cpu(raw); |
1da177e4 LT |
775 | return 0; |
776 | } | |
468039ee | 777 | EXPORT_SYMBOL_GPL(xdr_decode_word); |
1da177e4 | 778 | |
bd8100e7 | 779 | int |
1e78957e | 780 | xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj) |
bd8100e7 | 781 | { |
9f162d2a | 782 | __be32 raw = cpu_to_be32(obj); |
bd8100e7 AG |
783 | |
784 | return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj)); | |
785 | } | |
468039ee | 786 | EXPORT_SYMBOL_GPL(xdr_encode_word); |
bd8100e7 | 787 | |
1da177e4 LT |
788 | /* If the netobj starting offset bytes from the start of xdr_buf is contained |
789 | * entirely in the head or the tail, set object to point to it; otherwise | |
790 | * try to find space for it at the end of the tail, copy it there, and | |
791 | * set obj to point to it. */ | |
bee57c99 | 792 | int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset) |
1da177e4 | 793 | { |
bee57c99 | 794 | struct xdr_buf subbuf; |
1da177e4 | 795 | |
bd8100e7 | 796 | if (xdr_decode_word(buf, offset, &obj->len)) |
bee57c99 TM |
797 | return -EFAULT; |
798 | if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len)) | |
799 | return -EFAULT; | |
800 | ||
801 | /* Is the obj contained entirely in the head? */ | |
802 | obj->data = subbuf.head[0].iov_base; | |
803 | if (subbuf.head[0].iov_len == obj->len) | |
804 | return 0; | |
805 | /* ..or is the obj contained entirely in the tail? */ | |
806 | obj->data = subbuf.tail[0].iov_base; | |
807 | if (subbuf.tail[0].iov_len == obj->len) | |
808 | return 0; | |
809 | ||
810 | /* use end of tail as storage for obj: | |
811 | * (We don't copy to the beginning because then we'd have | |
812 | * to worry about doing a potentially overlapping copy. | |
813 | * This assumes the object is at most half the length of the | |
814 | * tail.) */ | |
815 | if (obj->len > buf->buflen - buf->len) | |
816 | return -ENOMEM; | |
817 | if (buf->tail[0].iov_len != 0) | |
818 | obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len; | |
819 | else | |
820 | obj->data = buf->head[0].iov_base + buf->head[0].iov_len; | |
821 | __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len); | |
1da177e4 | 822 | return 0; |
1da177e4 | 823 | } |
468039ee | 824 | EXPORT_SYMBOL_GPL(xdr_buf_read_netobj); |
bd8100e7 AG |
825 | |
826 | /* Returns 0 on success, or else a negative error code. */ | |
827 | static int | |
828 | xdr_xcode_array2(struct xdr_buf *buf, unsigned int base, | |
829 | struct xdr_array2_desc *desc, int encode) | |
830 | { | |
831 | char *elem = NULL, *c; | |
832 | unsigned int copied = 0, todo, avail_here; | |
833 | struct page **ppages = NULL; | |
834 | int err; | |
835 | ||
836 | if (encode) { | |
837 | if (xdr_encode_word(buf, base, desc->array_len) != 0) | |
838 | return -EINVAL; | |
839 | } else { | |
840 | if (xdr_decode_word(buf, base, &desc->array_len) != 0 || | |
58fcb8df | 841 | desc->array_len > desc->array_maxlen || |
bd8100e7 AG |
842 | (unsigned long) base + 4 + desc->array_len * |
843 | desc->elem_size > buf->len) | |
844 | return -EINVAL; | |
845 | } | |
846 | base += 4; | |
847 | ||
848 | if (!desc->xcode) | |
849 | return 0; | |
850 | ||
851 | todo = desc->array_len * desc->elem_size; | |
852 | ||
853 | /* process head */ | |
854 | if (todo && base < buf->head->iov_len) { | |
855 | c = buf->head->iov_base + base; | |
856 | avail_here = min_t(unsigned int, todo, | |
857 | buf->head->iov_len - base); | |
858 | todo -= avail_here; | |
859 | ||
860 | while (avail_here >= desc->elem_size) { | |
861 | err = desc->xcode(desc, c); | |
862 | if (err) | |
863 | goto out; | |
864 | c += desc->elem_size; | |
865 | avail_here -= desc->elem_size; | |
866 | } | |
867 | if (avail_here) { | |
868 | if (!elem) { | |
869 | elem = kmalloc(desc->elem_size, GFP_KERNEL); | |
870 | err = -ENOMEM; | |
871 | if (!elem) | |
872 | goto out; | |
873 | } | |
874 | if (encode) { | |
875 | err = desc->xcode(desc, elem); | |
876 | if (err) | |
877 | goto out; | |
878 | memcpy(c, elem, avail_here); | |
879 | } else | |
880 | memcpy(elem, c, avail_here); | |
881 | copied = avail_here; | |
882 | } | |
883 | base = buf->head->iov_len; /* align to start of pages */ | |
884 | } | |
885 | ||
886 | /* process pages array */ | |
887 | base -= buf->head->iov_len; | |
888 | if (todo && base < buf->page_len) { | |
889 | unsigned int avail_page; | |
890 | ||
891 | avail_here = min(todo, buf->page_len - base); | |
892 | todo -= avail_here; | |
893 | ||
894 | base += buf->page_base; | |
895 | ppages = buf->pages + (base >> PAGE_CACHE_SHIFT); | |
896 | base &= ~PAGE_CACHE_MASK; | |
897 | avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base, | |
898 | avail_here); | |
899 | c = kmap(*ppages) + base; | |
900 | ||
901 | while (avail_here) { | |
902 | avail_here -= avail_page; | |
903 | if (copied || avail_page < desc->elem_size) { | |
904 | unsigned int l = min(avail_page, | |
905 | desc->elem_size - copied); | |
906 | if (!elem) { | |
907 | elem = kmalloc(desc->elem_size, | |
908 | GFP_KERNEL); | |
909 | err = -ENOMEM; | |
910 | if (!elem) | |
911 | goto out; | |
912 | } | |
913 | if (encode) { | |
914 | if (!copied) { | |
915 | err = desc->xcode(desc, elem); | |
916 | if (err) | |
917 | goto out; | |
918 | } | |
919 | memcpy(c, elem + copied, l); | |
920 | copied += l; | |
921 | if (copied == desc->elem_size) | |
922 | copied = 0; | |
923 | } else { | |
924 | memcpy(elem + copied, c, l); | |
925 | copied += l; | |
926 | if (copied == desc->elem_size) { | |
927 | err = desc->xcode(desc, elem); | |
928 | if (err) | |
929 | goto out; | |
930 | copied = 0; | |
931 | } | |
932 | } | |
933 | avail_page -= l; | |
934 | c += l; | |
935 | } | |
936 | while (avail_page >= desc->elem_size) { | |
937 | err = desc->xcode(desc, c); | |
938 | if (err) | |
939 | goto out; | |
940 | c += desc->elem_size; | |
941 | avail_page -= desc->elem_size; | |
942 | } | |
943 | if (avail_page) { | |
944 | unsigned int l = min(avail_page, | |
945 | desc->elem_size - copied); | |
946 | if (!elem) { | |
947 | elem = kmalloc(desc->elem_size, | |
948 | GFP_KERNEL); | |
949 | err = -ENOMEM; | |
950 | if (!elem) | |
951 | goto out; | |
952 | } | |
953 | if (encode) { | |
954 | if (!copied) { | |
955 | err = desc->xcode(desc, elem); | |
956 | if (err) | |
957 | goto out; | |
958 | } | |
959 | memcpy(c, elem + copied, l); | |
960 | copied += l; | |
961 | if (copied == desc->elem_size) | |
962 | copied = 0; | |
963 | } else { | |
964 | memcpy(elem + copied, c, l); | |
965 | copied += l; | |
966 | if (copied == desc->elem_size) { | |
967 | err = desc->xcode(desc, elem); | |
968 | if (err) | |
969 | goto out; | |
970 | copied = 0; | |
971 | } | |
972 | } | |
973 | } | |
974 | if (avail_here) { | |
975 | kunmap(*ppages); | |
976 | ppages++; | |
977 | c = kmap(*ppages); | |
978 | } | |
979 | ||
980 | avail_page = min(avail_here, | |
981 | (unsigned int) PAGE_CACHE_SIZE); | |
982 | } | |
983 | base = buf->page_len; /* align to start of tail */ | |
984 | } | |
985 | ||
986 | /* process tail */ | |
987 | base -= buf->page_len; | |
988 | if (todo) { | |
989 | c = buf->tail->iov_base + base; | |
990 | if (copied) { | |
991 | unsigned int l = desc->elem_size - copied; | |
992 | ||
993 | if (encode) | |
994 | memcpy(c, elem + copied, l); | |
995 | else { | |
996 | memcpy(elem + copied, c, l); | |
997 | err = desc->xcode(desc, elem); | |
998 | if (err) | |
999 | goto out; | |
1000 | } | |
1001 | todo -= l; | |
1002 | c += l; | |
1003 | } | |
1004 | while (todo) { | |
1005 | err = desc->xcode(desc, c); | |
1006 | if (err) | |
1007 | goto out; | |
1008 | c += desc->elem_size; | |
1009 | todo -= desc->elem_size; | |
1010 | } | |
1011 | } | |
1012 | err = 0; | |
1013 | ||
1014 | out: | |
a51482bd | 1015 | kfree(elem); |
bd8100e7 AG |
1016 | if (ppages) |
1017 | kunmap(*ppages); | |
1018 | return err; | |
1019 | } | |
1020 | ||
1021 | int | |
1022 | xdr_decode_array2(struct xdr_buf *buf, unsigned int base, | |
1023 | struct xdr_array2_desc *desc) | |
1024 | { | |
1025 | if (base >= buf->len) | |
1026 | return -EINVAL; | |
1027 | ||
1028 | return xdr_xcode_array2(buf, base, desc, 0); | |
1029 | } | |
468039ee | 1030 | EXPORT_SYMBOL_GPL(xdr_decode_array2); |
bd8100e7 AG |
1031 | |
1032 | int | |
1033 | xdr_encode_array2(struct xdr_buf *buf, unsigned int base, | |
1034 | struct xdr_array2_desc *desc) | |
1035 | { | |
1036 | if ((unsigned long) base + 4 + desc->array_len * desc->elem_size > | |
1037 | buf->head->iov_len + buf->page_len + buf->tail->iov_len) | |
1038 | return -EINVAL; | |
1039 | ||
1040 | return xdr_xcode_array2(buf, base, desc, 1); | |
1041 | } | |
468039ee | 1042 | EXPORT_SYMBOL_GPL(xdr_encode_array2); |
37a4e6cb OK |
1043 | |
1044 | int | |
1045 | xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, | |
cca5172a | 1046 | int (*actor)(struct scatterlist *, void *), void *data) |
37a4e6cb OK |
1047 | { |
1048 | int i, ret = 0; | |
1049 | unsigned page_len, thislen, page_offset; | |
1050 | struct scatterlist sg[1]; | |
1051 | ||
68e3f5dd HX |
1052 | sg_init_table(sg, 1); |
1053 | ||
37a4e6cb OK |
1054 | if (offset >= buf->head[0].iov_len) { |
1055 | offset -= buf->head[0].iov_len; | |
1056 | } else { | |
1057 | thislen = buf->head[0].iov_len - offset; | |
1058 | if (thislen > len) | |
1059 | thislen = len; | |
1060 | sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); | |
1061 | ret = actor(sg, data); | |
1062 | if (ret) | |
1063 | goto out; | |
1064 | offset = 0; | |
1065 | len -= thislen; | |
1066 | } | |
1067 | if (len == 0) | |
1068 | goto out; | |
1069 | ||
1070 | if (offset >= buf->page_len) { | |
1071 | offset -= buf->page_len; | |
1072 | } else { | |
1073 | page_len = buf->page_len - offset; | |
1074 | if (page_len > len) | |
1075 | page_len = len; | |
1076 | len -= page_len; | |
1077 | page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1); | |
1078 | i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT; | |
1079 | thislen = PAGE_CACHE_SIZE - page_offset; | |
1080 | do { | |
1081 | if (thislen > page_len) | |
1082 | thislen = page_len; | |
642f1490 | 1083 | sg_set_page(sg, buf->pages[i], thislen, page_offset); |
37a4e6cb OK |
1084 | ret = actor(sg, data); |
1085 | if (ret) | |
1086 | goto out; | |
1087 | page_len -= thislen; | |
1088 | i++; | |
1089 | page_offset = 0; | |
1090 | thislen = PAGE_CACHE_SIZE; | |
1091 | } while (page_len != 0); | |
1092 | offset = 0; | |
1093 | } | |
1094 | if (len == 0) | |
1095 | goto out; | |
1096 | if (offset < buf->tail[0].iov_len) { | |
1097 | thislen = buf->tail[0].iov_len - offset; | |
1098 | if (thislen > len) | |
1099 | thislen = len; | |
1100 | sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); | |
1101 | ret = actor(sg, data); | |
1102 | len -= thislen; | |
1103 | } | |
1104 | if (len != 0) | |
1105 | ret = -EINVAL; | |
1106 | out: | |
1107 | return ret; | |
1108 | } | |
468039ee | 1109 | EXPORT_SYMBOL_GPL(xdr_process_buf); |
37a4e6cb | 1110 |