1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/net/sunrpc/xdr.c
7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/types.h>
13 #include <linux/string.h>
14 #include <linux/kernel.h>
15 #include <linux/pagemap.h>
16 #include <linux/errno.h>
17 #include <linux/sunrpc/xdr.h>
18 #include <linux/sunrpc/msg_prot.h>
19 #include <linux/bvec.h>
20 #include <trace/events/sunrpc.h>
22 static void _copy_to_pages(struct page **, size_t, const char *, size_t);
26 * XDR functions for basic NFS types
29 xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj)
31 unsigned int quadlen = XDR_QUADLEN(obj->len);
33 p[quadlen] = 0; /* zero trailing bytes */
34 *p++ = cpu_to_be32(obj->len);
35 memcpy(p, obj->data, obj->len);
36 return p + XDR_QUADLEN(obj->len);
38 EXPORT_SYMBOL_GPL(xdr_encode_netobj);
41 xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj)
45 if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ)
49 return p + XDR_QUADLEN(len);
51 EXPORT_SYMBOL_GPL(xdr_decode_netobj);
54 * xdr_encode_opaque_fixed - Encode fixed length opaque data
55 * @p: pointer to current position in XDR buffer.
56 * @ptr: pointer to data to encode (or NULL)
57 * @nbytes: size of data.
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.
64 * Returns the updated current XDR buffer position
67 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes)
69 if (likely(nbytes != 0)) {
70 unsigned int quadlen = XDR_QUADLEN(nbytes);
71 unsigned int padding = (quadlen << 2) - nbytes;
74 memcpy(p, ptr, nbytes);
76 memset((char *)p + nbytes, 0, padding);
81 EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed);
84 * xdr_encode_opaque - Encode variable length opaque data
85 * @p: pointer to current position in XDR buffer.
86 * @ptr: pointer to data to encode (or NULL)
87 * @nbytes: size of data.
89 * Returns the updated current XDR buffer position
91 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes)
93 *p++ = cpu_to_be32(nbytes);
94 return xdr_encode_opaque_fixed(p, ptr, nbytes);
96 EXPORT_SYMBOL_GPL(xdr_encode_opaque);
99 xdr_encode_string(__be32 *p, const char *string)
101 return xdr_encode_array(p, string, strlen(string));
103 EXPORT_SYMBOL_GPL(xdr_encode_string);
106 xdr_decode_string_inplace(__be32 *p, char **sp,
107 unsigned int *lenp, unsigned int maxlen)
111 len = be32_to_cpu(*p++);
116 return p + XDR_QUADLEN(len);
118 EXPORT_SYMBOL_GPL(xdr_decode_string_inplace);
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
127 xdr_terminate_string(struct xdr_buf *buf, const u32 len)
131 kaddr = kmap_atomic(buf->pages[0]);
132 kaddr[buf->page_base + len] = '\0';
133 kunmap_atomic(kaddr);
135 EXPORT_SYMBOL_GPL(xdr_terminate_string);
138 xdr_buf_pagecount(struct xdr_buf *buf)
142 return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
146 xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp)
148 size_t i, n = xdr_buf_pagecount(buf);
150 if (n != 0 && buf->bvec == NULL) {
151 buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp);
154 for (i = 0; i < n; i++) {
155 buf->bvec[i].bv_page = buf->pages[i];
156 buf->bvec[i].bv_len = PAGE_SIZE;
157 buf->bvec[i].bv_offset = 0;
164 xdr_free_bvec(struct xdr_buf *buf)
171 * xdr_inline_pages - Prepare receive buffer for a large reply
172 * @xdr: xdr_buf into which reply will be placed
173 * @offset: expected offset where data payload will start, in bytes
174 * @pages: vector of struct page pointers
175 * @base: offset in first page where receive should start, in bytes
176 * @len: expected size of the upper layer data payload, in bytes
180 xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
181 struct page **pages, unsigned int base, unsigned int len)
183 struct kvec *head = xdr->head;
184 struct kvec *tail = xdr->tail;
185 char *buf = (char *)head->iov_base;
186 unsigned int buflen = head->iov_len;
188 head->iov_len = offset;
191 xdr->page_base = base;
194 tail->iov_base = buf + offset;
195 tail->iov_len = buflen - offset;
196 if ((xdr->page_len & 3) == 0)
197 tail->iov_len -= sizeof(__be32);
201 EXPORT_SYMBOL_GPL(xdr_inline_pages);
204 * Helper routines for doing 'memmove' like operations on a struct xdr_buf
208 * _shift_data_left_pages
209 * @pages: vector of pages containing both the source and dest memory area.
210 * @pgto_base: page vector address of destination
211 * @pgfrom_base: page vector address of source
212 * @len: number of bytes to copy
214 * Note: the addresses pgto_base and pgfrom_base are both calculated in
216 * if a memory area starts at byte 'base' in page 'pages[i]',
217 * then its address is given as (i << PAGE_CACHE_SHIFT) + base
218 * Alse note: pgto_base must be < pgfrom_base, but the memory areas
219 * they point to may overlap.
222 _shift_data_left_pages(struct page **pages, size_t pgto_base,
223 size_t pgfrom_base, size_t len)
225 struct page **pgfrom, **pgto;
229 BUG_ON(pgfrom_base <= pgto_base);
231 pgto = pages + (pgto_base >> PAGE_SHIFT);
232 pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
234 pgto_base &= ~PAGE_MASK;
235 pgfrom_base &= ~PAGE_MASK;
238 if (pgto_base >= PAGE_SIZE) {
242 if (pgfrom_base >= PAGE_SIZE){
248 if (copy > (PAGE_SIZE - pgto_base))
249 copy = PAGE_SIZE - pgto_base;
250 if (copy > (PAGE_SIZE - pgfrom_base))
251 copy = PAGE_SIZE - pgfrom_base;
253 vto = kmap_atomic(*pgto);
254 if (*pgto != *pgfrom) {
255 vfrom = kmap_atomic(*pgfrom);
256 memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
257 kunmap_atomic(vfrom);
259 memmove(vto + pgto_base, vto + pgfrom_base, copy);
260 flush_dcache_page(*pgto);
266 } while ((len -= copy) != 0);
270 _shift_data_left_tail(struct xdr_buf *buf, unsigned int pgto, size_t len)
272 struct kvec *tail = buf->tail;
274 if (len > tail->iov_len)
277 _copy_to_pages(buf->pages,
278 buf->page_base + pgto,
279 (char *)tail->iov_base,
281 tail->iov_len -= len;
283 if (tail->iov_len > 0)
284 memmove((char *)tail->iov_base,
285 tail->iov_base + len,
290 * _shift_data_right_pages
291 * @pages: vector of pages containing both the source and dest memory area.
292 * @pgto_base: page vector address of destination
293 * @pgfrom_base: page vector address of source
294 * @len: number of bytes to copy
296 * Note: the addresses pgto_base and pgfrom_base are both calculated in
298 * if a memory area starts at byte 'base' in page 'pages[i]',
299 * then its address is given as (i << PAGE_SHIFT) + base
300 * Also note: pgfrom_base must be < pgto_base, but the memory areas
301 * they point to may overlap.
304 _shift_data_right_pages(struct page **pages, size_t pgto_base,
305 size_t pgfrom_base, size_t len)
307 struct page **pgfrom, **pgto;
311 BUG_ON(pgto_base <= pgfrom_base);
316 pgto = pages + (pgto_base >> PAGE_SHIFT);
317 pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
319 pgto_base &= ~PAGE_MASK;
320 pgfrom_base &= ~PAGE_MASK;
323 /* Are any pointers crossing a page boundary? */
324 if (pgto_base == 0) {
325 pgto_base = PAGE_SIZE;
328 if (pgfrom_base == 0) {
329 pgfrom_base = PAGE_SIZE;
334 if (copy > pgto_base)
336 if (copy > pgfrom_base)
341 vto = kmap_atomic(*pgto);
342 if (*pgto != *pgfrom) {
343 vfrom = kmap_atomic(*pgfrom);
344 memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
345 kunmap_atomic(vfrom);
347 memmove(vto + pgto_base, vto + pgfrom_base, copy);
348 flush_dcache_page(*pgto);
351 } while ((len -= copy) != 0);
355 _shift_data_right_tail(struct xdr_buf *buf, unsigned int pgfrom, size_t len)
357 struct kvec *tail = buf->tail;
358 unsigned int tailbuf_len;
359 unsigned int result = 0;
362 tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len;
364 /* Shift the tail first */
365 if (tailbuf_len != 0) {
366 unsigned int free_space = tailbuf_len - tail->iov_len;
368 if (len < free_space)
370 if (len > free_space)
373 tail->iov_len += free_space;
376 if (tail->iov_len > len) {
377 char *p = (char *)tail->iov_base + len;
378 memmove(p, tail->iov_base, tail->iov_len - free_space);
379 result += tail->iov_len - free_space;
381 copy = tail->iov_len;
383 /* Copy from the inlined pages into the tail */
384 _copy_from_pages((char *)tail->iov_base,
386 buf->page_base + pgfrom,
396 * @pages: array of pages
397 * @pgbase: page vector address of destination
398 * @p: pointer to source data
401 * Copies data from an arbitrary memory location into an array of pages
402 * The copy is assumed to be non-overlapping.
405 _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
411 pgto = pages + (pgbase >> PAGE_SHIFT);
412 pgbase &= ~PAGE_MASK;
415 copy = PAGE_SIZE - pgbase;
419 vto = kmap_atomic(*pgto);
420 memcpy(vto + pgbase, p, copy);
428 if (pgbase == PAGE_SIZE) {
429 flush_dcache_page(*pgto);
435 flush_dcache_page(*pgto);
440 * @p: pointer to destination
441 * @pages: array of pages
442 * @pgbase: offset of source data
445 * Copies data into an arbitrary memory location from an array of pages
446 * The copy is assumed to be non-overlapping.
449 _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
451 struct page **pgfrom;
455 pgfrom = pages + (pgbase >> PAGE_SHIFT);
456 pgbase &= ~PAGE_MASK;
459 copy = PAGE_SIZE - pgbase;
463 vfrom = kmap_atomic(*pgfrom);
464 memcpy(p, vfrom + pgbase, copy);
465 kunmap_atomic(vfrom);
468 if (pgbase == PAGE_SIZE) {
474 } while ((len -= copy) != 0);
476 EXPORT_SYMBOL_GPL(_copy_from_pages);
480 * @pages: array of pages
481 * @pgbase: beginning page vector address
485 _zero_pages(struct page **pages, size_t pgbase, size_t len)
491 page = pages + (pgbase >> PAGE_SHIFT);
492 pgbase &= ~PAGE_MASK;
495 zero = PAGE_SIZE - pgbase;
499 vpage = kmap_atomic(*page);
500 memset(vpage + pgbase, 0, zero);
501 kunmap_atomic(vpage);
503 flush_dcache_page(*page);
507 } while ((len -= zero) != 0);
513 * @len: bytes to remove from buf->head[0]
515 * Shrinks XDR buffer's header kvec buf->head[0] by
516 * 'len' bytes. The extra data is not lost, but is instead
517 * moved into the inlined pages and/or the tail.
520 xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
522 struct kvec *head, *tail;
524 unsigned int pglen = buf->page_len;
531 WARN_ON_ONCE(len > head->iov_len);
532 if (len > head->iov_len)
535 /* Shift the tail first */
536 if (tail->iov_len != 0) {
537 if (tail->iov_len > len) {
538 copy = tail->iov_len - len;
539 memmove((char *)tail->iov_base + len,
540 tail->iov_base, copy);
543 /* Copy from the inlined pages into the tail */
548 if (offs >= tail->iov_len)
550 else if (copy > tail->iov_len - offs)
551 copy = tail->iov_len - offs;
553 _copy_from_pages((char *)tail->iov_base + offs,
555 buf->page_base + pglen + offs - len,
559 /* Do we also need to copy data from the head into the tail ? */
561 offs = copy = len - pglen;
562 if (copy > tail->iov_len)
563 copy = tail->iov_len;
564 memcpy(tail->iov_base,
565 (char *)head->iov_base +
566 head->iov_len - offs,
571 /* Now handle pages */
574 _shift_data_right_pages(buf->pages,
575 buf->page_base + len,
581 _copy_to_pages(buf->pages, buf->page_base,
582 (char *)head->iov_base + head->iov_len - len,
586 head->iov_len -= len;
588 /* Have we truncated the message? */
589 if (buf->len > buf->buflen)
590 buf->len = buf->buflen;
596 * xdr_shrink_pagelen - shrinks buf->pages by up to @len bytes
598 * @len: bytes to remove from buf->pages
600 * The extra data is not lost, but is instead moved into buf->tail.
601 * Returns the actual number of bytes moved.
604 xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
606 unsigned int pglen = buf->page_len;
609 if (len > buf->page_len)
610 len = buf-> page_len;
612 result = _shift_data_right_tail(buf, pglen - len, len);
613 buf->page_len -= len;
615 /* Have we truncated the message? */
616 if (buf->len > buf->buflen)
617 buf->len = buf->buflen;
623 xdr_shift_buf(struct xdr_buf *buf, size_t len)
625 xdr_shrink_bufhead(buf, len);
627 EXPORT_SYMBOL_GPL(xdr_shift_buf);
630 * xdr_stream_pos - Return the current offset from the start of the xdr_stream
631 * @xdr: pointer to struct xdr_stream
633 unsigned int xdr_stream_pos(const struct xdr_stream *xdr)
635 return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2;
637 EXPORT_SYMBOL_GPL(xdr_stream_pos);
640 * xdr_page_pos - Return the current offset from the start of the xdr pages
641 * @xdr: pointer to struct xdr_stream
643 unsigned int xdr_page_pos(const struct xdr_stream *xdr)
645 unsigned int pos = xdr_stream_pos(xdr);
647 WARN_ON(pos < xdr->buf->head[0].iov_len);
648 return pos - xdr->buf->head[0].iov_len;
650 EXPORT_SYMBOL_GPL(xdr_page_pos);
653 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
654 * @xdr: pointer to xdr_stream struct
655 * @buf: pointer to XDR buffer in which to encode data
656 * @p: current pointer inside XDR buffer
657 * @rqst: pointer to controlling rpc_rqst, for debugging
659 * Note: at the moment the RPC client only passes the length of our
660 * scratch buffer in the xdr_buf's header kvec. Previously this
661 * meant we needed to call xdr_adjust_iovec() after encoding the
662 * data. With the new scheme, the xdr_stream manages the details
663 * of the buffer length, and takes care of adjusting the kvec
666 void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
667 struct rpc_rqst *rqst)
669 struct kvec *iov = buf->head;
670 int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
672 xdr_set_scratch_buffer(xdr, NULL, 0);
673 BUG_ON(scratch_len < 0);
676 xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len);
677 xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len);
678 BUG_ON(iov->iov_len > scratch_len);
680 if (p != xdr->p && p != NULL) {
683 BUG_ON(p < xdr->p || p > xdr->end);
684 len = (char *)p - (char *)xdr->p;
691 EXPORT_SYMBOL_GPL(xdr_init_encode);
694 * xdr_commit_encode - Ensure all data is written to buffer
695 * @xdr: pointer to xdr_stream
697 * We handle encoding across page boundaries by giving the caller a
698 * temporary location to write to, then later copying the data into
699 * place; xdr_commit_encode does that copying.
701 * Normally the caller doesn't need to call this directly, as the
702 * following xdr_reserve_space will do it. But an explicit call may be
703 * required at the end of encoding, or any other time when the xdr_buf
704 * data might be read.
706 inline void xdr_commit_encode(struct xdr_stream *xdr)
708 int shift = xdr->scratch.iov_len;
713 page = page_address(*xdr->page_ptr);
714 memcpy(xdr->scratch.iov_base, page, shift);
715 memmove(page, page + shift, (void *)xdr->p - page);
716 xdr->scratch.iov_len = 0;
718 EXPORT_SYMBOL_GPL(xdr_commit_encode);
720 static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr,
725 int frag1bytes, frag2bytes;
727 if (nbytes > PAGE_SIZE)
728 goto out_overflow; /* Bigger buffers require special handling */
729 if (xdr->buf->len + nbytes > xdr->buf->buflen)
730 goto out_overflow; /* Sorry, we're totally out of space */
731 frag1bytes = (xdr->end - xdr->p) << 2;
732 frag2bytes = nbytes - frag1bytes;
734 xdr->iov->iov_len += frag1bytes;
736 xdr->buf->page_len += frag1bytes;
740 * If the last encode didn't end exactly on a page boundary, the
741 * next one will straddle boundaries. Encode into the next
742 * page, then copy it back later in xdr_commit_encode. We use
743 * the "scratch" iov to track any temporarily unused fragment of
744 * space at the end of the previous buffer:
746 xdr->scratch.iov_base = xdr->p;
747 xdr->scratch.iov_len = frag1bytes;
748 p = page_address(*xdr->page_ptr);
750 * Note this is where the next encode will start after we've
751 * shifted this one back:
753 xdr->p = (void *)p + frag2bytes;
754 space_left = xdr->buf->buflen - xdr->buf->len;
755 if (space_left - frag1bytes >= PAGE_SIZE)
756 xdr->end = (void *)p + PAGE_SIZE;
758 xdr->end = (void *)p + space_left - frag1bytes;
760 xdr->buf->page_len += frag2bytes;
761 xdr->buf->len += nbytes;
764 trace_rpc_xdr_overflow(xdr, nbytes);
769 * xdr_reserve_space - Reserve buffer space for sending
770 * @xdr: pointer to xdr_stream
771 * @nbytes: number of bytes to reserve
773 * Checks that we have enough buffer space to encode 'nbytes' more
774 * bytes of data. If so, update the total xdr_buf length, and
775 * adjust the length of the current kvec.
777 __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
782 xdr_commit_encode(xdr);
783 /* align nbytes on the next 32-bit boundary */
786 q = p + (nbytes >> 2);
787 if (unlikely(q > xdr->end || q < p))
788 return xdr_get_next_encode_buffer(xdr, nbytes);
791 xdr->iov->iov_len += nbytes;
793 xdr->buf->page_len += nbytes;
794 xdr->buf->len += nbytes;
797 EXPORT_SYMBOL_GPL(xdr_reserve_space);
801 * xdr_reserve_space_vec - Reserves a large amount of buffer space for sending
802 * @xdr: pointer to xdr_stream
803 * @vec: pointer to a kvec array
804 * @nbytes: number of bytes to reserve
806 * Reserves enough buffer space to encode 'nbytes' of data and stores the
807 * pointers in 'vec'. The size argument passed to xdr_reserve_space() is
808 * determined based on the number of bytes remaining in the current page to
809 * avoid invalidating iov_base pointers when xdr_commit_encode() is called.
811 int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbytes)
818 * svcrdma requires every READ payload to start somewhere
821 if (xdr->iov == xdr->buf->head) {
827 thislen = xdr->buf->page_len % PAGE_SIZE;
828 thislen = min_t(size_t, nbytes, PAGE_SIZE - thislen);
830 p = xdr_reserve_space(xdr, thislen);
835 vec[v].iov_len = thislen;
842 EXPORT_SYMBOL_GPL(xdr_reserve_space_vec);
845 * xdr_truncate_encode - truncate an encode buffer
846 * @xdr: pointer to xdr_stream
847 * @len: new length of buffer
849 * Truncates the xdr stream, so that xdr->buf->len == len,
850 * and xdr->p points at offset len from the start of the buffer, and
851 * head, tail, and page lengths are adjusted to correspond.
853 * If this means moving xdr->p to a different buffer, we assume that
854 * the end pointer should be set to the end of the current page,
855 * except in the case of the head buffer when we assume the head
856 * buffer's current length represents the end of the available buffer.
858 * This is *not* safe to use on a buffer that already has inlined page
859 * cache pages (as in a zero-copy server read reply), except for the
860 * simple case of truncating from one position in the tail to another.
863 void xdr_truncate_encode(struct xdr_stream *xdr, size_t len)
865 struct xdr_buf *buf = xdr->buf;
866 struct kvec *head = buf->head;
867 struct kvec *tail = buf->tail;
871 if (len > buf->len) {
875 xdr_commit_encode(xdr);
877 fraglen = min_t(int, buf->len - len, tail->iov_len);
878 tail->iov_len -= fraglen;
881 xdr->p = tail->iov_base + tail->iov_len;
882 WARN_ON_ONCE(!xdr->end);
883 WARN_ON_ONCE(!xdr->iov);
886 WARN_ON_ONCE(fraglen);
887 fraglen = min_t(int, buf->len - len, buf->page_len);
888 buf->page_len -= fraglen;
891 new = buf->page_base + buf->page_len;
893 xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT);
896 xdr->p = page_address(*xdr->page_ptr);
897 xdr->end = (void *)xdr->p + PAGE_SIZE;
898 xdr->p = (void *)xdr->p + (new % PAGE_SIZE);
899 WARN_ON_ONCE(xdr->iov);
903 xdr->end = head->iov_base + head->iov_len;
904 /* (otherwise assume xdr->end is already set) */
908 xdr->p = head->iov_base + head->iov_len;
909 xdr->iov = buf->head;
911 EXPORT_SYMBOL(xdr_truncate_encode);
914 * xdr_restrict_buflen - decrease available buffer space
915 * @xdr: pointer to xdr_stream
916 * @newbuflen: new maximum number of bytes available
918 * Adjust our idea of how much space is available in the buffer.
919 * If we've already used too much space in the buffer, returns -1.
920 * If the available space is already smaller than newbuflen, returns 0
921 * and does nothing. Otherwise, adjusts xdr->buf->buflen to newbuflen
922 * and ensures xdr->end is set at most offset newbuflen from the start
925 int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen)
927 struct xdr_buf *buf = xdr->buf;
928 int left_in_this_buf = (void *)xdr->end - (void *)xdr->p;
929 int end_offset = buf->len + left_in_this_buf;
931 if (newbuflen < 0 || newbuflen < buf->len)
933 if (newbuflen > buf->buflen)
935 if (newbuflen < end_offset)
936 xdr->end = (void *)xdr->end + newbuflen - end_offset;
937 buf->buflen = newbuflen;
940 EXPORT_SYMBOL(xdr_restrict_buflen);
943 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
944 * @xdr: pointer to xdr_stream
945 * @pages: list of pages
946 * @base: offset of first byte
947 * @len: length of data in bytes
950 void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base,
953 struct xdr_buf *buf = xdr->buf;
954 struct kvec *iov = buf->tail;
956 buf->page_base = base;
959 iov->iov_base = (char *)xdr->p;
964 unsigned int pad = 4 - (len & 3);
966 BUG_ON(xdr->p >= xdr->end);
967 iov->iov_base = (char *)xdr->p + (len & 3);
975 EXPORT_SYMBOL_GPL(xdr_write_pages);
977 static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,
980 if (len > iov->iov_len)
982 xdr->p = (__be32*)iov->iov_base;
983 xdr->end = (__be32*)(iov->iov_base + len);
985 xdr->page_ptr = NULL;
988 static int xdr_set_page_base(struct xdr_stream *xdr,
989 unsigned int base, unsigned int len)
997 maxlen = xdr->buf->page_len;
1004 base += xdr->buf->page_base;
1006 pgnr = base >> PAGE_SHIFT;
1007 xdr->page_ptr = &xdr->buf->pages[pgnr];
1008 kaddr = page_address(*xdr->page_ptr);
1010 pgoff = base & ~PAGE_MASK;
1011 xdr->p = (__be32*)(kaddr + pgoff);
1013 pgend = pgoff + len;
1014 if (pgend > PAGE_SIZE)
1016 xdr->end = (__be32*)(kaddr + pgend);
1021 static void xdr_set_page(struct xdr_stream *xdr, unsigned int base,
1024 if (xdr_set_page_base(xdr, base, len) < 0)
1025 xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2);
1028 static void xdr_set_next_page(struct xdr_stream *xdr)
1030 unsigned int newbase;
1032 newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
1033 newbase -= xdr->buf->page_base;
1035 xdr_set_page(xdr, newbase, PAGE_SIZE);
1038 static bool xdr_set_next_buffer(struct xdr_stream *xdr)
1040 if (xdr->page_ptr != NULL)
1041 xdr_set_next_page(xdr);
1042 else if (xdr->iov == xdr->buf->head) {
1043 xdr_set_page(xdr, 0, PAGE_SIZE);
1045 return xdr->p != xdr->end;
1049 * xdr_init_decode - Initialize an xdr_stream for decoding data.
1050 * @xdr: pointer to xdr_stream struct
1051 * @buf: pointer to XDR buffer from which to decode data
1052 * @p: current pointer inside XDR buffer
1053 * @rqst: pointer to controlling rpc_rqst, for debugging
1055 void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
1056 struct rpc_rqst *rqst)
1059 xdr->scratch.iov_base = NULL;
1060 xdr->scratch.iov_len = 0;
1061 xdr->nwords = XDR_QUADLEN(buf->len);
1062 if (buf->head[0].iov_len != 0)
1063 xdr_set_iov(xdr, buf->head, buf->len);
1064 else if (buf->page_len != 0)
1065 xdr_set_page_base(xdr, 0, buf->len);
1067 xdr_set_iov(xdr, buf->head, buf->len);
1068 if (p != NULL && p > xdr->p && xdr->end >= p) {
1069 xdr->nwords -= p - xdr->p;
1074 EXPORT_SYMBOL_GPL(xdr_init_decode);
1077 * xdr_init_decode_pages - Initialize an xdr_stream for decoding into pages
1078 * @xdr: pointer to xdr_stream struct
1079 * @buf: pointer to XDR buffer from which to decode data
1080 * @pages: list of pages to decode into
1081 * @len: length in bytes of buffer in pages
1083 void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
1084 struct page **pages, unsigned int len)
1086 memset(buf, 0, sizeof(*buf));
1088 buf->page_len = len;
1091 xdr_init_decode(xdr, buf, NULL, NULL);
1093 EXPORT_SYMBOL_GPL(xdr_init_decode_pages);
1095 static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
1097 unsigned int nwords = XDR_QUADLEN(nbytes);
1099 __be32 *q = p + nwords;
1101 if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p))
1104 xdr->nwords -= nwords;
1109 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
1110 * @xdr: pointer to xdr_stream struct
1111 * @buf: pointer to an empty buffer
1112 * @buflen: size of 'buf'
1114 * The scratch buffer is used when decoding from an array of pages.
1115 * If an xdr_inline_decode() call spans across page boundaries, then
1116 * we copy the data into the scratch buffer in order to allow linear
1119 void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
1121 xdr->scratch.iov_base = buf;
1122 xdr->scratch.iov_len = buflen;
1124 EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer);
1126 static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
1129 char *cpdest = xdr->scratch.iov_base;
1130 size_t cplen = (char *)xdr->end - (char *)xdr->p;
1132 if (nbytes > xdr->scratch.iov_len)
1134 p = __xdr_inline_decode(xdr, cplen);
1137 memcpy(cpdest, p, cplen);
1138 if (!xdr_set_next_buffer(xdr))
1142 p = __xdr_inline_decode(xdr, nbytes);
1145 memcpy(cpdest, p, nbytes);
1146 return xdr->scratch.iov_base;
1148 trace_rpc_xdr_overflow(xdr, nbytes);
1153 * xdr_inline_decode - Retrieve XDR data to decode
1154 * @xdr: pointer to xdr_stream struct
1155 * @nbytes: number of bytes of data to decode
1157 * Check if the input buffer is long enough to enable us to decode
1158 * 'nbytes' more bytes of data starting at the current position.
1159 * If so return the current pointer, then update the current
1162 __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
1166 if (unlikely(nbytes == 0))
1168 if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
1170 p = __xdr_inline_decode(xdr, nbytes);
1173 return xdr_copy_to_scratch(xdr, nbytes);
1175 trace_rpc_xdr_overflow(xdr, nbytes);
1178 EXPORT_SYMBOL_GPL(xdr_inline_decode);
1180 static void xdr_realign_pages(struct xdr_stream *xdr)
1182 struct xdr_buf *buf = xdr->buf;
1183 struct kvec *iov = buf->head;
1184 unsigned int cur = xdr_stream_pos(xdr);
1185 unsigned int copied, offset;
1187 /* Realign pages to current pointer position */
1188 if (iov->iov_len > cur) {
1189 offset = iov->iov_len - cur;
1190 copied = xdr_shrink_bufhead(buf, offset);
1191 trace_rpc_xdr_alignment(xdr, offset, copied);
1192 xdr->nwords = XDR_QUADLEN(buf->len - cur);
1196 static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len)
1198 struct xdr_buf *buf = xdr->buf;
1199 unsigned int nwords = XDR_QUADLEN(len);
1200 unsigned int cur = xdr_stream_pos(xdr);
1201 unsigned int copied, offset;
1203 if (xdr->nwords == 0)
1206 xdr_realign_pages(xdr);
1207 if (nwords > xdr->nwords) {
1208 nwords = xdr->nwords;
1211 if (buf->page_len <= len)
1212 len = buf->page_len;
1213 else if (nwords < xdr->nwords) {
1214 /* Truncate page data and move it into the tail */
1215 offset = buf->page_len - len;
1216 copied = xdr_shrink_pagelen(buf, offset);
1217 trace_rpc_xdr_alignment(xdr, offset, copied);
1218 xdr->nwords = XDR_QUADLEN(buf->len - cur);
1224 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
1225 * @xdr: pointer to xdr_stream struct
1226 * @len: number of bytes of page data
1228 * Moves data beyond the current pointer position from the XDR head[] buffer
1229 * into the page list. Any data that lies beyond current position + "len"
1230 * bytes is moved into the XDR tail[].
1232 * Returns the number of XDR encoded bytes now contained in the pages
1234 unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
1236 struct xdr_buf *buf = xdr->buf;
1238 unsigned int nwords;
1240 unsigned int padding;
1242 len = xdr_align_pages(xdr, len);
1245 nwords = XDR_QUADLEN(len);
1246 padding = (nwords << 2) - len;
1247 xdr->iov = iov = buf->tail;
1248 /* Compute remaining message length. */
1249 end = ((xdr->nwords - nwords) << 2) + padding;
1250 if (end > iov->iov_len)
1254 * Position current pointer at beginning of tail, and
1255 * set remaining message length.
1257 xdr->p = (__be32 *)((char *)iov->iov_base + padding);
1258 xdr->end = (__be32 *)((char *)iov->iov_base + end);
1259 xdr->page_ptr = NULL;
1260 xdr->nwords = XDR_QUADLEN(end - padding);
1263 EXPORT_SYMBOL_GPL(xdr_read_pages);
1265 uint64_t xdr_align_data(struct xdr_stream *xdr, uint64_t offset, uint32_t length)
1267 struct xdr_buf *buf = xdr->buf;
1268 unsigned int from, bytes;
1269 unsigned int shift = 0;
1271 if ((offset + length) < offset ||
1272 (offset + length) > buf->page_len)
1273 length = buf->page_len - offset;
1275 xdr_realign_pages(xdr);
1276 from = xdr_page_pos(xdr);
1277 bytes = xdr->nwords << 2;
1281 /* Move page data to the left */
1282 if (from > offset) {
1283 shift = min_t(unsigned int, bytes, buf->page_len - from);
1284 _shift_data_left_pages(buf->pages,
1285 buf->page_base + offset,
1286 buf->page_base + from,
1290 /* Move tail data into the pages, if necessary */
1292 _shift_data_left_tail(buf, offset + shift, bytes);
1295 xdr->nwords -= XDR_QUADLEN(length);
1296 xdr_set_page(xdr, from + length, PAGE_SIZE);
1299 EXPORT_SYMBOL_GPL(xdr_align_data);
1301 uint64_t xdr_expand_hole(struct xdr_stream *xdr, uint64_t offset, uint64_t length)
1303 struct xdr_buf *buf = xdr->buf;
1306 unsigned int truncated = 0;
1308 if ((offset + length) < offset ||
1309 (offset + length) > buf->page_len)
1310 length = buf->page_len - offset;
1312 xdr_realign_pages(xdr);
1313 from = xdr_page_pos(xdr);
1314 bytes = xdr->nwords << 2;
1316 if (offset + length + bytes > buf->page_len) {
1317 unsigned int shift = (offset + length + bytes) - buf->page_len;
1318 unsigned int res = _shift_data_right_tail(buf, from + bytes - shift, shift);
1319 truncated = shift - res;
1320 xdr->nwords -= XDR_QUADLEN(truncated);
1324 /* Now move the page data over and zero pages */
1326 _shift_data_right_pages(buf->pages,
1327 buf->page_base + offset + length,
1328 buf->page_base + from,
1330 _zero_pages(buf->pages, buf->page_base + offset, length);
1332 buf->len += length - (from - offset) - truncated;
1333 xdr_set_page(xdr, offset + length, PAGE_SIZE);
1336 EXPORT_SYMBOL_GPL(xdr_expand_hole);
1339 * xdr_enter_page - decode data from the XDR page
1340 * @xdr: pointer to xdr_stream struct
1341 * @len: number of bytes of page data
1343 * Moves data beyond the current pointer position from the XDR head[] buffer
1344 * into the page list. Any data that lies beyond current position + "len"
1345 * bytes is moved into the XDR tail[]. The current pointer is then
1346 * repositioned at the beginning of the first XDR page.
1348 void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
1350 len = xdr_align_pages(xdr, len);
1352 * Position current pointer at beginning of tail, and
1353 * set remaining message length.
1356 xdr_set_page_base(xdr, 0, len);
1358 EXPORT_SYMBOL_GPL(xdr_enter_page);
1360 static const struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
1363 xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf)
1365 buf->head[0] = *iov;
1366 buf->tail[0] = empty_iov;
1368 buf->buflen = buf->len = iov->iov_len;
1370 EXPORT_SYMBOL_GPL(xdr_buf_from_iov);
1373 * xdr_buf_subsegment - set subbuf to a portion of buf
1374 * @buf: an xdr buffer
1375 * @subbuf: the result buffer
1376 * @base: beginning of range in bytes
1377 * @len: length of range in bytes
1379 * sets @subbuf to an xdr buffer representing the portion of @buf of
1380 * length @len starting at offset @base.
1382 * @buf and @subbuf may be pointers to the same struct xdr_buf.
1384 * Returns -1 if base of length are out of bounds.
1387 xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
1388 unsigned int base, unsigned int len)
1390 subbuf->buflen = subbuf->len = len;
1391 if (base < buf->head[0].iov_len) {
1392 subbuf->head[0].iov_base = buf->head[0].iov_base + base;
1393 subbuf->head[0].iov_len = min_t(unsigned int, len,
1394 buf->head[0].iov_len - base);
1395 len -= subbuf->head[0].iov_len;
1398 base -= buf->head[0].iov_len;
1399 subbuf->head[0].iov_base = buf->head[0].iov_base;
1400 subbuf->head[0].iov_len = 0;
1403 if (base < buf->page_len) {
1404 subbuf->page_len = min(buf->page_len - base, len);
1405 base += buf->page_base;
1406 subbuf->page_base = base & ~PAGE_MASK;
1407 subbuf->pages = &buf->pages[base >> PAGE_SHIFT];
1408 len -= subbuf->page_len;
1411 base -= buf->page_len;
1412 subbuf->pages = buf->pages;
1413 subbuf->page_base = 0;
1414 subbuf->page_len = 0;
1417 if (base < buf->tail[0].iov_len) {
1418 subbuf->tail[0].iov_base = buf->tail[0].iov_base + base;
1419 subbuf->tail[0].iov_len = min_t(unsigned int, len,
1420 buf->tail[0].iov_len - base);
1421 len -= subbuf->tail[0].iov_len;
1424 base -= buf->tail[0].iov_len;
1425 subbuf->tail[0].iov_base = buf->tail[0].iov_base;
1426 subbuf->tail[0].iov_len = 0;
1433 EXPORT_SYMBOL_GPL(xdr_buf_subsegment);
1436 * xdr_buf_trim - lop at most "len" bytes off the end of "buf"
1437 * @buf: buf to be trimmed
1438 * @len: number of bytes to reduce "buf" by
1440 * Trim an xdr_buf by the given number of bytes by fixing up the lengths. Note
1441 * that it's possible that we'll trim less than that amount if the xdr_buf is
1442 * too small, or if (for instance) it's all in the head and the parser has
1443 * already read too far into it.
1445 void xdr_buf_trim(struct xdr_buf *buf, unsigned int len)
1448 unsigned int trim = len;
1450 if (buf->tail[0].iov_len) {
1451 cur = min_t(size_t, buf->tail[0].iov_len, trim);
1452 buf->tail[0].iov_len -= cur;
1458 if (buf->page_len) {
1459 cur = min_t(unsigned int, buf->page_len, trim);
1460 buf->page_len -= cur;
1466 if (buf->head[0].iov_len) {
1467 cur = min_t(size_t, buf->head[0].iov_len, trim);
1468 buf->head[0].iov_len -= cur;
1472 buf->len -= (len - trim);
1474 EXPORT_SYMBOL_GPL(xdr_buf_trim);
1476 static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len)
1478 unsigned int this_len;
1480 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
1481 memcpy(obj, subbuf->head[0].iov_base, this_len);
1484 this_len = min_t(unsigned int, len, subbuf->page_len);
1486 _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len);
1489 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
1490 memcpy(obj, subbuf->tail[0].iov_base, this_len);
1493 /* obj is assumed to point to allocated memory of size at least len: */
1494 int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len)
1496 struct xdr_buf subbuf;
1499 status = xdr_buf_subsegment(buf, &subbuf, base, len);
1502 __read_bytes_from_xdr_buf(&subbuf, obj, len);
1505 EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf);
1507 static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len)
1509 unsigned int this_len;
1511 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
1512 memcpy(subbuf->head[0].iov_base, obj, this_len);
1515 this_len = min_t(unsigned int, len, subbuf->page_len);
1517 _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len);
1520 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
1521 memcpy(subbuf->tail[0].iov_base, obj, this_len);
1524 /* obj is assumed to point to allocated memory of size at least len: */
1525 int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len)
1527 struct xdr_buf subbuf;
1530 status = xdr_buf_subsegment(buf, &subbuf, base, len);
1533 __write_bytes_to_xdr_buf(&subbuf, obj, len);
1536 EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf);
1539 xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj)
1544 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
1547 *obj = be32_to_cpu(raw);
1550 EXPORT_SYMBOL_GPL(xdr_decode_word);
1553 xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj)
1555 __be32 raw = cpu_to_be32(obj);
1557 return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
1559 EXPORT_SYMBOL_GPL(xdr_encode_word);
1561 /* Returns 0 on success, or else a negative error code. */
1563 xdr_xcode_array2(struct xdr_buf *buf, unsigned int base,
1564 struct xdr_array2_desc *desc, int encode)
1566 char *elem = NULL, *c;
1567 unsigned int copied = 0, todo, avail_here;
1568 struct page **ppages = NULL;
1572 if (xdr_encode_word(buf, base, desc->array_len) != 0)
1575 if (xdr_decode_word(buf, base, &desc->array_len) != 0 ||
1576 desc->array_len > desc->array_maxlen ||
1577 (unsigned long) base + 4 + desc->array_len *
1578 desc->elem_size > buf->len)
1586 todo = desc->array_len * desc->elem_size;
1589 if (todo && base < buf->head->iov_len) {
1590 c = buf->head->iov_base + base;
1591 avail_here = min_t(unsigned int, todo,
1592 buf->head->iov_len - base);
1595 while (avail_here >= desc->elem_size) {
1596 err = desc->xcode(desc, c);
1599 c += desc->elem_size;
1600 avail_here -= desc->elem_size;
1604 elem = kmalloc(desc->elem_size, GFP_KERNEL);
1610 err = desc->xcode(desc, elem);
1613 memcpy(c, elem, avail_here);
1615 memcpy(elem, c, avail_here);
1616 copied = avail_here;
1618 base = buf->head->iov_len; /* align to start of pages */
1621 /* process pages array */
1622 base -= buf->head->iov_len;
1623 if (todo && base < buf->page_len) {
1624 unsigned int avail_page;
1626 avail_here = min(todo, buf->page_len - base);
1629 base += buf->page_base;
1630 ppages = buf->pages + (base >> PAGE_SHIFT);
1632 avail_page = min_t(unsigned int, PAGE_SIZE - base,
1634 c = kmap(*ppages) + base;
1636 while (avail_here) {
1637 avail_here -= avail_page;
1638 if (copied || avail_page < desc->elem_size) {
1639 unsigned int l = min(avail_page,
1640 desc->elem_size - copied);
1642 elem = kmalloc(desc->elem_size,
1650 err = desc->xcode(desc, elem);
1654 memcpy(c, elem + copied, l);
1656 if (copied == desc->elem_size)
1659 memcpy(elem + copied, c, l);
1661 if (copied == desc->elem_size) {
1662 err = desc->xcode(desc, elem);
1671 while (avail_page >= desc->elem_size) {
1672 err = desc->xcode(desc, c);
1675 c += desc->elem_size;
1676 avail_page -= desc->elem_size;
1679 unsigned int l = min(avail_page,
1680 desc->elem_size - copied);
1682 elem = kmalloc(desc->elem_size,
1690 err = desc->xcode(desc, elem);
1694 memcpy(c, elem + copied, l);
1696 if (copied == desc->elem_size)
1699 memcpy(elem + copied, c, l);
1701 if (copied == desc->elem_size) {
1702 err = desc->xcode(desc, elem);
1715 avail_page = min(avail_here,
1716 (unsigned int) PAGE_SIZE);
1718 base = buf->page_len; /* align to start of tail */
1722 base -= buf->page_len;
1724 c = buf->tail->iov_base + base;
1726 unsigned int l = desc->elem_size - copied;
1729 memcpy(c, elem + copied, l);
1731 memcpy(elem + copied, c, l);
1732 err = desc->xcode(desc, elem);
1740 err = desc->xcode(desc, c);
1743 c += desc->elem_size;
1744 todo -= desc->elem_size;
1757 xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
1758 struct xdr_array2_desc *desc)
1760 if (base >= buf->len)
1763 return xdr_xcode_array2(buf, base, desc, 0);
1765 EXPORT_SYMBOL_GPL(xdr_decode_array2);
1768 xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
1769 struct xdr_array2_desc *desc)
1771 if ((unsigned long) base + 4 + desc->array_len * desc->elem_size >
1772 buf->head->iov_len + buf->page_len + buf->tail->iov_len)
1775 return xdr_xcode_array2(buf, base, desc, 1);
1777 EXPORT_SYMBOL_GPL(xdr_encode_array2);
1780 xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len,
1781 int (*actor)(struct scatterlist *, void *), void *data)
1784 unsigned int page_len, thislen, page_offset;
1785 struct scatterlist sg[1];
1787 sg_init_table(sg, 1);
1789 if (offset >= buf->head[0].iov_len) {
1790 offset -= buf->head[0].iov_len;
1792 thislen = buf->head[0].iov_len - offset;
1795 sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
1796 ret = actor(sg, data);
1805 if (offset >= buf->page_len) {
1806 offset -= buf->page_len;
1808 page_len = buf->page_len - offset;
1812 page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1);
1813 i = (offset + buf->page_base) >> PAGE_SHIFT;
1814 thislen = PAGE_SIZE - page_offset;
1816 if (thislen > page_len)
1818 sg_set_page(sg, buf->pages[i], thislen, page_offset);
1819 ret = actor(sg, data);
1822 page_len -= thislen;
1825 thislen = PAGE_SIZE;
1826 } while (page_len != 0);
1831 if (offset < buf->tail[0].iov_len) {
1832 thislen = buf->tail[0].iov_len - offset;
1835 sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
1836 ret = actor(sg, data);
1844 EXPORT_SYMBOL_GPL(xdr_process_buf);
1847 * xdr_stream_decode_opaque - Decode variable length opaque
1848 * @xdr: pointer to xdr_stream
1849 * @ptr: location to store opaque data
1850 * @size: size of storage buffer @ptr
1853 * On success, returns size of object stored in *@ptr
1854 * %-EBADMSG on XDR buffer overflow
1855 * %-EMSGSIZE on overflow of storage buffer @ptr
1857 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size)
1862 ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
1865 memcpy(ptr, p, ret);
1868 EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque);
1871 * xdr_stream_decode_opaque_dup - Decode and duplicate variable length opaque
1872 * @xdr: pointer to xdr_stream
1873 * @ptr: location to store pointer to opaque data
1874 * @maxlen: maximum acceptable object size
1875 * @gfp_flags: GFP mask to use
1878 * On success, returns size of object stored in *@ptr
1879 * %-EBADMSG on XDR buffer overflow
1880 * %-EMSGSIZE if the size of the object would exceed @maxlen
1881 * %-ENOMEM on memory allocation failure
1883 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
1884 size_t maxlen, gfp_t gfp_flags)
1889 ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
1891 *ptr = kmemdup(p, ret, gfp_flags);
1899 EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup);
1902 * xdr_stream_decode_string - Decode variable length string
1903 * @xdr: pointer to xdr_stream
1904 * @str: location to store string
1905 * @size: size of storage buffer @str
1908 * On success, returns length of NUL-terminated string stored in *@str
1909 * %-EBADMSG on XDR buffer overflow
1910 * %-EMSGSIZE on overflow of storage buffer @str
1912 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size)
1917 ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
1919 memcpy(str, p, ret);
1926 EXPORT_SYMBOL_GPL(xdr_stream_decode_string);
1929 * xdr_stream_decode_string_dup - Decode and duplicate variable length string
1930 * @xdr: pointer to xdr_stream
1931 * @str: location to store pointer to string
1932 * @maxlen: maximum acceptable string length
1933 * @gfp_flags: GFP mask to use
1936 * On success, returns length of NUL-terminated string stored in *@ptr
1937 * %-EBADMSG on XDR buffer overflow
1938 * %-EMSGSIZE if the size of the string would exceed @maxlen
1939 * %-ENOMEM on memory allocation failure
1941 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
1942 size_t maxlen, gfp_t gfp_flags)
1947 ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
1949 char *s = kmalloc(ret + 1, gfp_flags);
1961 EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup);