2 * linux/net/sunrpc/xdr.c
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
9 #include <linux/types.h>
10 #include <linux/socket.h>
11 #include <linux/string.h>
12 #include <linux/kernel.h>
13 #include <linux/pagemap.h>
14 #include <linux/errno.h>
16 #include <linux/net.h>
18 #include <linux/sunrpc/xdr.h>
19 #include <linux/sunrpc/msg_prot.h>
22 * XDR functions for basic NFS types
25 xdr_encode_netobj(u32 *p, const struct xdr_netobj *obj)
27 unsigned int quadlen = XDR_QUADLEN(obj->len);
29 p[quadlen] = 0; /* zero trailing bytes */
30 *p++ = htonl(obj->len);
31 memcpy(p, obj->data, obj->len);
32 return p + XDR_QUADLEN(obj->len);
36 xdr_decode_netobj(u32 *p, struct xdr_netobj *obj)
40 if ((len = ntohl(*p++)) > XDR_MAX_NETOBJ)
44 return p + XDR_QUADLEN(len);
48 * xdr_encode_opaque_fixed - Encode fixed length opaque data
49 * @p: pointer to current position in XDR buffer.
50 * @ptr: pointer to data to encode (or NULL)
51 * @nbytes: size of data.
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.
58 * Returns the updated current XDR buffer position
61 u32 *xdr_encode_opaque_fixed(u32 *p, const void *ptr, unsigned int nbytes)
63 if (likely(nbytes != 0)) {
64 unsigned int quadlen = XDR_QUADLEN(nbytes);
65 unsigned int padding = (quadlen << 2) - nbytes;
68 memcpy(p, ptr, nbytes);
70 memset((char *)p + nbytes, 0, padding);
75 EXPORT_SYMBOL(xdr_encode_opaque_fixed);
78 * xdr_encode_opaque - Encode variable length opaque data
79 * @p: pointer to current position in XDR buffer.
80 * @ptr: pointer to data to encode (or NULL)
81 * @nbytes: size of data.
83 * Returns the updated current XDR buffer position
85 u32 *xdr_encode_opaque(u32 *p, const void *ptr, unsigned int nbytes)
88 return xdr_encode_opaque_fixed(p, ptr, nbytes);
90 EXPORT_SYMBOL(xdr_encode_opaque);
93 xdr_encode_string(u32 *p, const char *string)
95 return xdr_encode_array(p, string, strlen(string));
99 xdr_decode_string(u32 *p, char **sp, int *lenp, int maxlen)
104 if ((len = ntohl(*p++)) > maxlen)
108 if ((len % 4) != 0) {
111 string = (char *) (p - 1);
112 memmove(string, p, len);
116 return p + XDR_QUADLEN(len);
120 xdr_decode_string_inplace(u32 *p, char **sp, int *lenp, int maxlen)
124 if ((len = ntohl(*p++)) > maxlen)
128 return p + XDR_QUADLEN(len);
132 xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base,
135 struct kvec *tail = xdr->tail;
139 xdr->page_base = base;
142 p = (u32 *)xdr->head[0].iov_base + XDR_QUADLEN(xdr->head[0].iov_len);
147 unsigned int pad = 4 - (len & 3);
150 tail->iov_base = (char *)p + (len & 3);
159 xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
160 struct page **pages, unsigned int base, unsigned int len)
162 struct kvec *head = xdr->head;
163 struct kvec *tail = xdr->tail;
164 char *buf = (char *)head->iov_base;
165 unsigned int buflen = head->iov_len;
167 head->iov_len = offset;
170 xdr->page_base = base;
173 tail->iov_base = buf + offset;
174 tail->iov_len = buflen - offset;
181 xdr_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen,
182 struct xdr_buf *xdr, unsigned int base, int msgflags)
184 struct page **ppage = xdr->pages;
185 unsigned int len, pglen = xdr->page_len;
187 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
189 len = xdr->head[0].iov_len;
190 if (base < len || (addr != NULL && base == 0)) {
192 .iov_base = xdr->head[0].iov_base + base,
193 .iov_len = len - base,
195 struct msghdr msg = {
197 .msg_namelen = addrlen,
198 .msg_flags = msgflags,
201 msg.msg_flags |= MSG_MORE;
203 if (iov.iov_len != 0)
204 err = kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
206 err = kernel_sendmsg(sock, &msg, NULL, 0, 0);
211 if (err != iov.iov_len)
223 if (base || xdr->page_base) {
225 base += xdr->page_base;
226 ppage += base >> PAGE_CACHE_SHIFT;
227 base &= ~PAGE_CACHE_MASK;
230 sendpage = sock->ops->sendpage ? : sock_no_sendpage;
232 int flags = msgflags;
234 len = PAGE_CACHE_SIZE;
240 if (pglen != len || xdr->tail[0].iov_len != 0)
243 /* Hmm... We might be dealing with highmem pages */
244 if (PageHighMem(*ppage))
245 sendpage = sock_no_sendpage;
246 err = sendpage(sock, *ppage, base, len, flags);
255 } while ((pglen -= len) != 0);
257 len = xdr->tail[0].iov_len;
260 .iov_base = xdr->tail[0].iov_base + base,
261 .iov_len = len - base,
263 struct msghdr msg = {
264 .msg_flags = msgflags,
266 err = kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
278 * Helper routines for doing 'memmove' like operations on a struct xdr_buf
280 * _shift_data_right_pages
281 * @pages: vector of pages containing both the source and dest memory area.
282 * @pgto_base: page vector address of destination
283 * @pgfrom_base: page vector address of source
284 * @len: number of bytes to copy
286 * Note: the addresses pgto_base and pgfrom_base are both calculated in
288 * if a memory area starts at byte 'base' in page 'pages[i]',
289 * then its address is given as (i << PAGE_CACHE_SHIFT) + base
290 * Also note: pgfrom_base must be < pgto_base, but the memory areas
291 * they point to may overlap.
294 _shift_data_right_pages(struct page **pages, size_t pgto_base,
295 size_t pgfrom_base, size_t len)
297 struct page **pgfrom, **pgto;
301 BUG_ON(pgto_base <= pgfrom_base);
306 pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT);
307 pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT);
309 pgto_base &= ~PAGE_CACHE_MASK;
310 pgfrom_base &= ~PAGE_CACHE_MASK;
313 /* Are any pointers crossing a page boundary? */
314 if (pgto_base == 0) {
315 flush_dcache_page(*pgto);
316 pgto_base = PAGE_CACHE_SIZE;
319 if (pgfrom_base == 0) {
320 pgfrom_base = PAGE_CACHE_SIZE;
325 if (copy > pgto_base)
327 if (copy > pgfrom_base)
332 vto = kmap_atomic(*pgto, KM_USER0);
333 vfrom = kmap_atomic(*pgfrom, KM_USER1);
334 memmove(vto + pgto_base, vfrom + pgfrom_base, copy);
335 kunmap_atomic(vfrom, KM_USER1);
336 kunmap_atomic(vto, KM_USER0);
338 } while ((len -= copy) != 0);
339 flush_dcache_page(*pgto);
344 * @pages: array of pages
345 * @pgbase: page vector address of destination
346 * @p: pointer to source data
349 * Copies data from an arbitrary memory location into an array of pages
350 * The copy is assumed to be non-overlapping.
353 _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
359 pgto = pages + (pgbase >> PAGE_CACHE_SHIFT);
360 pgbase &= ~PAGE_CACHE_MASK;
363 copy = PAGE_CACHE_SIZE - pgbase;
367 vto = kmap_atomic(*pgto, KM_USER0);
368 memcpy(vto + pgbase, p, copy);
369 kunmap_atomic(vto, KM_USER0);
372 if (pgbase == PAGE_CACHE_SIZE) {
373 flush_dcache_page(*pgto);
379 } while ((len -= copy) != 0);
380 flush_dcache_page(*pgto);
385 * @p: pointer to destination
386 * @pages: array of pages
387 * @pgbase: offset of source data
390 * Copies data into an arbitrary memory location from an array of pages
391 * The copy is assumed to be non-overlapping.
394 _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
396 struct page **pgfrom;
400 pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT);
401 pgbase &= ~PAGE_CACHE_MASK;
404 copy = PAGE_CACHE_SIZE - pgbase;
408 vfrom = kmap_atomic(*pgfrom, KM_USER0);
409 memcpy(p, vfrom + pgbase, copy);
410 kunmap_atomic(vfrom, KM_USER0);
413 if (pgbase == PAGE_CACHE_SIZE) {
419 } while ((len -= copy) != 0);
425 * @len: bytes to remove from buf->head[0]
427 * Shrinks XDR buffer's header kvec buf->head[0] by
428 * 'len' bytes. The extra data is not lost, but is instead
429 * moved into the inlined pages and/or the tail.
432 xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
434 struct kvec *head, *tail;
436 unsigned int pglen = buf->page_len;
440 BUG_ON (len > head->iov_len);
442 /* Shift the tail first */
443 if (tail->iov_len != 0) {
444 if (tail->iov_len > len) {
445 copy = tail->iov_len - len;
446 memmove((char *)tail->iov_base + len,
447 tail->iov_base, copy);
449 /* Copy from the inlined pages into the tail */
454 if (offs >= tail->iov_len)
456 else if (copy > tail->iov_len - offs)
457 copy = tail->iov_len - offs;
459 _copy_from_pages((char *)tail->iov_base + offs,
461 buf->page_base + pglen + offs - len,
463 /* Do we also need to copy data from the head into the tail ? */
465 offs = copy = len - pglen;
466 if (copy > tail->iov_len)
467 copy = tail->iov_len;
468 memcpy(tail->iov_base,
469 (char *)head->iov_base +
470 head->iov_len - offs,
474 /* Now handle pages */
477 _shift_data_right_pages(buf->pages,
478 buf->page_base + len,
484 _copy_to_pages(buf->pages, buf->page_base,
485 (char *)head->iov_base + head->iov_len - len,
488 head->iov_len -= len;
490 /* Have we truncated the message? */
491 if (buf->len > buf->buflen)
492 buf->len = buf->buflen;
498 * @len: bytes to remove from buf->pages
500 * Shrinks XDR buffer's page array buf->pages by
501 * 'len' bytes. The extra data is not lost, but is instead
502 * moved into the tail.
505 xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
510 unsigned int pglen = buf->page_len;
513 BUG_ON (len > pglen);
515 /* Shift the tail first */
516 if (tail->iov_len != 0) {
517 p = (char *)tail->iov_base + len;
518 if (tail->iov_len > len) {
519 copy = tail->iov_len - len;
520 memmove(p, tail->iov_base, copy);
523 /* Copy from the inlined pages into the tail */
525 if (copy > tail->iov_len)
526 copy = tail->iov_len;
527 _copy_from_pages((char *)tail->iov_base,
528 buf->pages, buf->page_base + pglen - len,
531 buf->page_len -= len;
533 /* Have we truncated the message? */
534 if (buf->len > buf->buflen)
535 buf->len = buf->buflen;
539 xdr_shift_buf(struct xdr_buf *buf, size_t len)
541 xdr_shrink_bufhead(buf, len);
545 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
546 * @xdr: pointer to xdr_stream struct
547 * @buf: pointer to XDR buffer in which to encode data
548 * @p: current pointer inside XDR buffer
550 * Note: at the moment the RPC client only passes the length of our
551 * scratch buffer in the xdr_buf's header kvec. Previously this
552 * meant we needed to call xdr_adjust_iovec() after encoding the
553 * data. With the new scheme, the xdr_stream manages the details
554 * of the buffer length, and takes care of adjusting the kvec
557 void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p)
559 struct kvec *iov = buf->head;
560 int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
562 BUG_ON(scratch_len < 0);
565 xdr->p = (uint32_t *)((char *)iov->iov_base + iov->iov_len);
566 xdr->end = (uint32_t *)((char *)iov->iov_base + scratch_len);
567 BUG_ON(iov->iov_len > scratch_len);
569 if (p != xdr->p && p != NULL) {
572 BUG_ON(p < xdr->p || p > xdr->end);
573 len = (char *)p - (char *)xdr->p;
579 EXPORT_SYMBOL(xdr_init_encode);
582 * xdr_reserve_space - Reserve buffer space for sending
583 * @xdr: pointer to xdr_stream
584 * @nbytes: number of bytes to reserve
586 * Checks that we have enough buffer space to encode 'nbytes' more
587 * bytes of data. If so, update the total xdr_buf length, and
588 * adjust the length of the current kvec.
590 uint32_t * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
592 uint32_t *p = xdr->p;
595 /* align nbytes on the next 32-bit boundary */
598 q = p + (nbytes >> 2);
599 if (unlikely(q > xdr->end || q < p))
602 xdr->iov->iov_len += nbytes;
603 xdr->buf->len += nbytes;
606 EXPORT_SYMBOL(xdr_reserve_space);
609 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
610 * @xdr: pointer to xdr_stream
611 * @pages: list of pages
612 * @base: offset of first byte
613 * @len: length of data in bytes
616 void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base,
619 struct xdr_buf *buf = xdr->buf;
620 struct kvec *iov = buf->tail;
622 buf->page_base = base;
625 iov->iov_base = (char *)xdr->p;
630 unsigned int pad = 4 - (len & 3);
632 BUG_ON(xdr->p >= xdr->end);
633 iov->iov_base = (char *)xdr->p + (len & 3);
641 EXPORT_SYMBOL(xdr_write_pages);
644 * xdr_init_decode - Initialize an xdr_stream for decoding data.
645 * @xdr: pointer to xdr_stream struct
646 * @buf: pointer to XDR buffer from which to decode data
647 * @p: current pointer inside XDR buffer
649 void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p)
651 struct kvec *iov = buf->head;
652 unsigned int len = iov->iov_len;
659 xdr->end = (uint32_t *)((char *)iov->iov_base + len);
661 EXPORT_SYMBOL(xdr_init_decode);
664 * xdr_inline_decode - Retrieve non-page XDR data to decode
665 * @xdr: pointer to xdr_stream struct
666 * @nbytes: number of bytes of data to decode
668 * Check if the input buffer is long enough to enable us to decode
669 * 'nbytes' more bytes of data starting at the current position.
670 * If so return the current pointer, then update the current
673 uint32_t * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
675 uint32_t *p = xdr->p;
676 uint32_t *q = p + XDR_QUADLEN(nbytes);
678 if (unlikely(q > xdr->end || q < p))
683 EXPORT_SYMBOL(xdr_inline_decode);
686 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
687 * @xdr: pointer to xdr_stream struct
688 * @len: number of bytes of page data
690 * Moves data beyond the current pointer position from the XDR head[] buffer
691 * into the page list. Any data that lies beyond current position + "len"
692 * bytes is moved into the XDR tail[]. The current pointer is then
693 * repositioned at the beginning of the XDR tail.
695 void xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
697 struct xdr_buf *buf = xdr->buf;
703 /* Realign pages to current pointer position */
705 shift = iov->iov_len + (char *)iov->iov_base - (char *)xdr->p;
707 xdr_shrink_bufhead(buf, shift);
709 /* Truncate page data and move it into the tail */
710 if (buf->page_len > len)
711 xdr_shrink_pagelen(buf, buf->page_len - len);
712 padding = (XDR_QUADLEN(len) << 2) - len;
713 xdr->iov = iov = buf->tail;
714 /* Compute remaining message length. */
716 shift = buf->buflen - buf->len;
722 * Position current pointer at beginning of tail, and
723 * set remaining message length.
725 xdr->p = (uint32_t *)((char *)iov->iov_base + padding);
726 xdr->end = (uint32_t *)((char *)iov->iov_base + end);
728 EXPORT_SYMBOL(xdr_read_pages);
730 static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
733 xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf)
736 buf->tail[0] = empty_iov;
738 buf->buflen = buf->len = iov->iov_len;
741 /* Sets subiov to the intersection of iov with the buffer of length len
742 * starting base bytes after iov. Indicates empty intersection by setting
743 * length of subiov to zero. Decrements len by length of subiov, sets base
744 * to zero (or decrements it by length of iov if subiov is empty). */
746 iov_subsegment(struct kvec *iov, struct kvec *subiov, int *base, int *len)
748 if (*base > iov->iov_len) {
749 subiov->iov_base = NULL;
751 *base -= iov->iov_len;
753 subiov->iov_base = iov->iov_base + *base;
754 subiov->iov_len = min(*len, (int)iov->iov_len - *base);
757 *len -= subiov->iov_len;
760 /* Sets subbuf to the portion of buf of length len beginning base bytes
761 * from the start of buf. Returns -1 if base of length are out of bounds. */
763 xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
768 subbuf->buflen = subbuf->len = len;
769 iov_subsegment(buf->head, subbuf->head, &base, &len);
771 if (base < buf->page_len) {
772 i = (base + buf->page_base) >> PAGE_CACHE_SHIFT;
773 subbuf->pages = &buf->pages[i];
774 subbuf->page_base = (base + buf->page_base) & ~PAGE_CACHE_MASK;
775 subbuf->page_len = min((int)buf->page_len - base, len);
776 len -= subbuf->page_len;
779 base -= buf->page_len;
780 subbuf->page_len = 0;
783 iov_subsegment(buf->tail, subbuf->tail, &base, &len);
789 /* obj is assumed to point to allocated memory of size at least len: */
791 read_bytes_from_xdr_buf(struct xdr_buf *buf, int base, void *obj, int len)
793 struct xdr_buf subbuf;
797 status = xdr_buf_subsegment(buf, &subbuf, base, len);
800 this_len = min(len, (int)subbuf.head[0].iov_len);
801 memcpy(obj, subbuf.head[0].iov_base, this_len);
804 this_len = min(len, (int)subbuf.page_len);
806 _copy_from_pages(obj, subbuf.pages, subbuf.page_base, this_len);
809 this_len = min(len, (int)subbuf.tail[0].iov_len);
810 memcpy(obj, subbuf.tail[0].iov_base, this_len);
815 /* obj is assumed to point to allocated memory of size at least len: */
817 write_bytes_to_xdr_buf(struct xdr_buf *buf, int base, void *obj, int len)
819 struct xdr_buf subbuf;
823 status = xdr_buf_subsegment(buf, &subbuf, base, len);
826 this_len = min(len, (int)subbuf.head[0].iov_len);
827 memcpy(subbuf.head[0].iov_base, obj, this_len);
830 this_len = min(len, (int)subbuf.page_len);
832 _copy_to_pages(subbuf.pages, subbuf.page_base, obj, this_len);
835 this_len = min(len, (int)subbuf.tail[0].iov_len);
836 memcpy(subbuf.tail[0].iov_base, obj, this_len);
842 xdr_decode_word(struct xdr_buf *buf, int base, u32 *obj)
847 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
855 xdr_encode_word(struct xdr_buf *buf, int base, u32 obj)
857 u32 raw = htonl(obj);
859 return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
862 /* If the netobj starting offset bytes from the start of xdr_buf is contained
863 * entirely in the head or the tail, set object to point to it; otherwise
864 * try to find space for it at the end of the tail, copy it there, and
865 * set obj to point to it. */
867 xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, int offset)
869 u32 tail_offset = buf->head[0].iov_len + buf->page_len;
872 if (xdr_decode_word(buf, offset, &obj->len))
874 obj_end_offset = offset + 4 + obj->len;
876 if (obj_end_offset <= buf->head[0].iov_len) {
877 /* The obj is contained entirely in the head: */
878 obj->data = buf->head[0].iov_base + offset + 4;
879 } else if (offset + 4 >= tail_offset) {
880 if (obj_end_offset - tail_offset
881 > buf->tail[0].iov_len)
883 /* The obj is contained entirely in the tail: */
884 obj->data = buf->tail[0].iov_base
885 + offset - tail_offset + 4;
887 /* use end of tail as storage for obj:
888 * (We don't copy to the beginning because then we'd have
889 * to worry about doing a potentially overlapping copy.
890 * This assumes the object is at most half the length of the
892 if (obj->len > buf->tail[0].iov_len)
894 obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len -
896 if (read_bytes_from_xdr_buf(buf, offset + 4,
897 obj->data, obj->len))
906 /* Returns 0 on success, or else a negative error code. */
908 xdr_xcode_array2(struct xdr_buf *buf, unsigned int base,
909 struct xdr_array2_desc *desc, int encode)
911 char *elem = NULL, *c;
912 unsigned int copied = 0, todo, avail_here;
913 struct page **ppages = NULL;
917 if (xdr_encode_word(buf, base, desc->array_len) != 0)
920 if (xdr_decode_word(buf, base, &desc->array_len) != 0 ||
921 desc->array_len > desc->array_maxlen ||
922 (unsigned long) base + 4 + desc->array_len *
923 desc->elem_size > buf->len)
931 todo = desc->array_len * desc->elem_size;
934 if (todo && base < buf->head->iov_len) {
935 c = buf->head->iov_base + base;
936 avail_here = min_t(unsigned int, todo,
937 buf->head->iov_len - base);
940 while (avail_here >= desc->elem_size) {
941 err = desc->xcode(desc, c);
944 c += desc->elem_size;
945 avail_here -= desc->elem_size;
949 elem = kmalloc(desc->elem_size, GFP_KERNEL);
955 err = desc->xcode(desc, elem);
958 memcpy(c, elem, avail_here);
960 memcpy(elem, c, avail_here);
963 base = buf->head->iov_len; /* align to start of pages */
966 /* process pages array */
967 base -= buf->head->iov_len;
968 if (todo && base < buf->page_len) {
969 unsigned int avail_page;
971 avail_here = min(todo, buf->page_len - base);
974 base += buf->page_base;
975 ppages = buf->pages + (base >> PAGE_CACHE_SHIFT);
976 base &= ~PAGE_CACHE_MASK;
977 avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base,
979 c = kmap(*ppages) + base;
982 avail_here -= avail_page;
983 if (copied || avail_page < desc->elem_size) {
984 unsigned int l = min(avail_page,
985 desc->elem_size - copied);
987 elem = kmalloc(desc->elem_size,
995 err = desc->xcode(desc, elem);
999 memcpy(c, elem + copied, l);
1001 if (copied == desc->elem_size)
1004 memcpy(elem + copied, c, l);
1006 if (copied == desc->elem_size) {
1007 err = desc->xcode(desc, elem);
1016 while (avail_page >= desc->elem_size) {
1017 err = desc->xcode(desc, c);
1020 c += desc->elem_size;
1021 avail_page -= desc->elem_size;
1024 unsigned int l = min(avail_page,
1025 desc->elem_size - copied);
1027 elem = kmalloc(desc->elem_size,
1035 err = desc->xcode(desc, elem);
1039 memcpy(c, elem + copied, l);
1041 if (copied == desc->elem_size)
1044 memcpy(elem + copied, c, l);
1046 if (copied == desc->elem_size) {
1047 err = desc->xcode(desc, elem);
1060 avail_page = min(avail_here,
1061 (unsigned int) PAGE_CACHE_SIZE);
1063 base = buf->page_len; /* align to start of tail */
1067 base -= buf->page_len;
1069 c = buf->tail->iov_base + base;
1071 unsigned int l = desc->elem_size - copied;
1074 memcpy(c, elem + copied, l);
1076 memcpy(elem + copied, c, l);
1077 err = desc->xcode(desc, elem);
1085 err = desc->xcode(desc, c);
1088 c += desc->elem_size;
1089 todo -= desc->elem_size;
1103 xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
1104 struct xdr_array2_desc *desc)
1106 if (base >= buf->len)
1109 return xdr_xcode_array2(buf, base, desc, 0);
1113 xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
1114 struct xdr_array2_desc *desc)
1116 if ((unsigned long) base + 4 + desc->array_len * desc->elem_size >
1117 buf->head->iov_len + buf->page_len + buf->tail->iov_len)
1120 return xdr_xcode_array2(buf, base, desc, 1);