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2195 lines
55 KiB
2195 lines
55 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/net/sunrpc/xdr.c |
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* |
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* Generic XDR support. |
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* |
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* Copyright (C) 1995, 1996 Olaf Kirch <[email protected]> |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/types.h> |
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#include <linux/string.h> |
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#include <linux/kernel.h> |
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#include <linux/pagemap.h> |
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#include <linux/errno.h> |
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#include <linux/sunrpc/xdr.h> |
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#include <linux/sunrpc/msg_prot.h> |
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#include <linux/bvec.h> |
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#include <trace/events/sunrpc.h> |
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|
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static void _copy_to_pages(struct page **, size_t, const char *, size_t); |
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|
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|
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/* |
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* XDR functions for basic NFS types |
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*/ |
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__be32 * |
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xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj) |
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{ |
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unsigned int quadlen = XDR_QUADLEN(obj->len); |
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p[quadlen] = 0; /* zero trailing bytes */ |
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*p++ = cpu_to_be32(obj->len); |
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memcpy(p, obj->data, obj->len); |
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return p + XDR_QUADLEN(obj->len); |
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} |
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EXPORT_SYMBOL_GPL(xdr_encode_netobj); |
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|
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__be32 * |
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xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj) |
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{ |
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unsigned int len; |
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|
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if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ) |
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return NULL; |
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obj->len = len; |
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obj->data = (u8 *) p; |
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return p + XDR_QUADLEN(len); |
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} |
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EXPORT_SYMBOL_GPL(xdr_decode_netobj); |
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|
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/** |
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* xdr_encode_opaque_fixed - Encode fixed length opaque data |
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* @p: pointer to current position in XDR buffer. |
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* @ptr: pointer to data to encode (or NULL) |
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* @nbytes: size of data. |
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* |
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* Copy the array of data of length nbytes at ptr to the XDR buffer |
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* at position p, then align to the next 32-bit boundary by padding |
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* with zero bytes (see RFC1832). |
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* Note: if ptr is NULL, only the padding is performed. |
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* |
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* Returns the updated current XDR buffer position |
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* |
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*/ |
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__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes) |
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{ |
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if (likely(nbytes != 0)) { |
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unsigned int quadlen = XDR_QUADLEN(nbytes); |
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unsigned int padding = (quadlen << 2) - nbytes; |
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|
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if (ptr != NULL) |
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memcpy(p, ptr, nbytes); |
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if (padding != 0) |
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memset((char *)p + nbytes, 0, padding); |
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p += quadlen; |
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} |
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return p; |
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} |
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EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed); |
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|
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/** |
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* xdr_encode_opaque - Encode variable length opaque data |
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* @p: pointer to current position in XDR buffer. |
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* @ptr: pointer to data to encode (or NULL) |
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* @nbytes: size of data. |
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* |
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* Returns the updated current XDR buffer position |
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*/ |
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__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) |
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{ |
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*p++ = cpu_to_be32(nbytes); |
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return xdr_encode_opaque_fixed(p, ptr, nbytes); |
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} |
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EXPORT_SYMBOL_GPL(xdr_encode_opaque); |
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|
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__be32 * |
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xdr_encode_string(__be32 *p, const char *string) |
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{ |
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return xdr_encode_array(p, string, strlen(string)); |
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} |
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EXPORT_SYMBOL_GPL(xdr_encode_string); |
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__be32 * |
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xdr_decode_string_inplace(__be32 *p, char **sp, |
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unsigned int *lenp, unsigned int maxlen) |
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{ |
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u32 len; |
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|
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len = be32_to_cpu(*p++); |
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if (len > maxlen) |
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return NULL; |
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*lenp = len; |
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*sp = (char *) p; |
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return p + XDR_QUADLEN(len); |
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} |
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EXPORT_SYMBOL_GPL(xdr_decode_string_inplace); |
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|
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/** |
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* xdr_terminate_string - '\0'-terminate a string residing in an xdr_buf |
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* @buf: XDR buffer where string resides |
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* @len: length of string, in bytes |
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* |
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*/ |
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void xdr_terminate_string(const struct xdr_buf *buf, const u32 len) |
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{ |
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char *kaddr; |
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kaddr = kmap_atomic(buf->pages[0]); |
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kaddr[buf->page_base + len] = '\0'; |
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kunmap_atomic(kaddr); |
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} |
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EXPORT_SYMBOL_GPL(xdr_terminate_string); |
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size_t xdr_buf_pagecount(const struct xdr_buf *buf) |
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{ |
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if (!buf->page_len) |
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return 0; |
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return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
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} |
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int |
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xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp) |
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{ |
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size_t i, n = xdr_buf_pagecount(buf); |
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|
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if (n != 0 && buf->bvec == NULL) { |
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buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp); |
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if (!buf->bvec) |
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return -ENOMEM; |
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for (i = 0; i < n; i++) { |
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buf->bvec[i].bv_page = buf->pages[i]; |
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buf->bvec[i].bv_len = PAGE_SIZE; |
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buf->bvec[i].bv_offset = 0; |
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} |
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} |
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return 0; |
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} |
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|
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void |
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xdr_free_bvec(struct xdr_buf *buf) |
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{ |
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kfree(buf->bvec); |
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buf->bvec = NULL; |
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} |
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|
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/** |
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* xdr_inline_pages - Prepare receive buffer for a large reply |
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* @xdr: xdr_buf into which reply will be placed |
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* @offset: expected offset where data payload will start, in bytes |
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* @pages: vector of struct page pointers |
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* @base: offset in first page where receive should start, in bytes |
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* @len: expected size of the upper layer data payload, in bytes |
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* |
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*/ |
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void |
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xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, |
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struct page **pages, unsigned int base, unsigned int len) |
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{ |
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struct kvec *head = xdr->head; |
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struct kvec *tail = xdr->tail; |
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char *buf = (char *)head->iov_base; |
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unsigned int buflen = head->iov_len; |
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head->iov_len = offset; |
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xdr->pages = pages; |
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xdr->page_base = base; |
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xdr->page_len = len; |
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tail->iov_base = buf + offset; |
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tail->iov_len = buflen - offset; |
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xdr->buflen += len; |
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} |
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EXPORT_SYMBOL_GPL(xdr_inline_pages); |
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|
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/* |
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* Helper routines for doing 'memmove' like operations on a struct xdr_buf |
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*/ |
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|
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/** |
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* _shift_data_left_pages |
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* @pages: vector of pages containing both the source and dest memory area. |
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* @pgto_base: page vector address of destination |
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* @pgfrom_base: page vector address of source |
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* @len: number of bytes to copy |
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* |
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* Note: the addresses pgto_base and pgfrom_base are both calculated in |
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* the same way: |
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* if a memory area starts at byte 'base' in page 'pages[i]', |
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* then its address is given as (i << PAGE_CACHE_SHIFT) + base |
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* Alse note: pgto_base must be < pgfrom_base, but the memory areas |
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* they point to may overlap. |
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*/ |
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static void |
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_shift_data_left_pages(struct page **pages, size_t pgto_base, |
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size_t pgfrom_base, size_t len) |
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{ |
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struct page **pgfrom, **pgto; |
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char *vfrom, *vto; |
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size_t copy; |
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BUG_ON(pgfrom_base <= pgto_base); |
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if (!len) |
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return; |
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pgto = pages + (pgto_base >> PAGE_SHIFT); |
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pgfrom = pages + (pgfrom_base >> PAGE_SHIFT); |
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pgto_base &= ~PAGE_MASK; |
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pgfrom_base &= ~PAGE_MASK; |
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do { |
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if (pgto_base >= PAGE_SIZE) { |
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pgto_base = 0; |
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pgto++; |
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} |
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if (pgfrom_base >= PAGE_SIZE){ |
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pgfrom_base = 0; |
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pgfrom++; |
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} |
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copy = len; |
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if (copy > (PAGE_SIZE - pgto_base)) |
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copy = PAGE_SIZE - pgto_base; |
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if (copy > (PAGE_SIZE - pgfrom_base)) |
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copy = PAGE_SIZE - pgfrom_base; |
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|
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vto = kmap_atomic(*pgto); |
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if (*pgto != *pgfrom) { |
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vfrom = kmap_atomic(*pgfrom); |
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memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); |
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kunmap_atomic(vfrom); |
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} else |
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memmove(vto + pgto_base, vto + pgfrom_base, copy); |
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flush_dcache_page(*pgto); |
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kunmap_atomic(vto); |
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pgto_base += copy; |
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pgfrom_base += copy; |
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|
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} while ((len -= copy) != 0); |
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} |
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/** |
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* _shift_data_right_pages |
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* @pages: vector of pages containing both the source and dest memory area. |
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* @pgto_base: page vector address of destination |
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* @pgfrom_base: page vector address of source |
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* @len: number of bytes to copy |
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* |
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* Note: the addresses pgto_base and pgfrom_base are both calculated in |
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* the same way: |
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* if a memory area starts at byte 'base' in page 'pages[i]', |
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* then its address is given as (i << PAGE_SHIFT) + base |
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* Also note: pgfrom_base must be < pgto_base, but the memory areas |
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* they point to may overlap. |
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*/ |
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static void |
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_shift_data_right_pages(struct page **pages, size_t pgto_base, |
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size_t pgfrom_base, size_t len) |
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{ |
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struct page **pgfrom, **pgto; |
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char *vfrom, *vto; |
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size_t copy; |
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BUG_ON(pgto_base <= pgfrom_base); |
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if (!len) |
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return; |
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pgto_base += len; |
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pgfrom_base += len; |
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pgto = pages + (pgto_base >> PAGE_SHIFT); |
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pgfrom = pages + (pgfrom_base >> PAGE_SHIFT); |
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pgto_base &= ~PAGE_MASK; |
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pgfrom_base &= ~PAGE_MASK; |
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do { |
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/* Are any pointers crossing a page boundary? */ |
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if (pgto_base == 0) { |
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pgto_base = PAGE_SIZE; |
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pgto--; |
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} |
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if (pgfrom_base == 0) { |
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pgfrom_base = PAGE_SIZE; |
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pgfrom--; |
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} |
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copy = len; |
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if (copy > pgto_base) |
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copy = pgto_base; |
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if (copy > pgfrom_base) |
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copy = pgfrom_base; |
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pgto_base -= copy; |
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pgfrom_base -= copy; |
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vto = kmap_atomic(*pgto); |
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if (*pgto != *pgfrom) { |
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vfrom = kmap_atomic(*pgfrom); |
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memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); |
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kunmap_atomic(vfrom); |
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} else |
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memmove(vto + pgto_base, vto + pgfrom_base, copy); |
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flush_dcache_page(*pgto); |
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kunmap_atomic(vto); |
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|
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} while ((len -= copy) != 0); |
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} |
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/** |
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* _copy_to_pages |
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* @pages: array of pages |
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* @pgbase: page vector address of destination |
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* @p: pointer to source data |
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* @len: length |
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* |
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* Copies data from an arbitrary memory location into an array of pages |
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* The copy is assumed to be non-overlapping. |
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*/ |
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static void |
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_copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len) |
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{ |
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struct page **pgto; |
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char *vto; |
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size_t copy; |
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if (!len) |
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return; |
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pgto = pages + (pgbase >> PAGE_SHIFT); |
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pgbase &= ~PAGE_MASK; |
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for (;;) { |
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copy = PAGE_SIZE - pgbase; |
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if (copy > len) |
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copy = len; |
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vto = kmap_atomic(*pgto); |
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memcpy(vto + pgbase, p, copy); |
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kunmap_atomic(vto); |
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len -= copy; |
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if (len == 0) |
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break; |
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pgbase += copy; |
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if (pgbase == PAGE_SIZE) { |
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flush_dcache_page(*pgto); |
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pgbase = 0; |
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pgto++; |
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} |
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p += copy; |
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} |
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flush_dcache_page(*pgto); |
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} |
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|
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/** |
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* _copy_from_pages |
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* @p: pointer to destination |
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* @pages: array of pages |
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* @pgbase: offset of source data |
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* @len: length |
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* |
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* Copies data into an arbitrary memory location from an array of pages |
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* The copy is assumed to be non-overlapping. |
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*/ |
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void |
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_copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) |
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{ |
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struct page **pgfrom; |
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char *vfrom; |
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size_t copy; |
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if (!len) |
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return; |
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pgfrom = pages + (pgbase >> PAGE_SHIFT); |
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pgbase &= ~PAGE_MASK; |
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do { |
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copy = PAGE_SIZE - pgbase; |
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if (copy > len) |
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copy = len; |
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vfrom = kmap_atomic(*pgfrom); |
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memcpy(p, vfrom + pgbase, copy); |
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kunmap_atomic(vfrom); |
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pgbase += copy; |
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if (pgbase == PAGE_SIZE) { |
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pgbase = 0; |
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pgfrom++; |
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} |
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p += copy; |
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|
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} while ((len -= copy) != 0); |
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} |
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EXPORT_SYMBOL_GPL(_copy_from_pages); |
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static void xdr_buf_iov_zero(const struct kvec *iov, unsigned int base, |
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unsigned int len) |
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{ |
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if (base >= iov->iov_len) |
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return; |
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if (len > iov->iov_len - base) |
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len = iov->iov_len - base; |
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memset(iov->iov_base + base, 0, len); |
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} |
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|
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/** |
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* xdr_buf_pages_zero |
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* @buf: xdr_buf |
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* @pgbase: beginning offset |
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* @len: length |
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*/ |
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static void xdr_buf_pages_zero(const struct xdr_buf *buf, unsigned int pgbase, |
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unsigned int len) |
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{ |
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struct page **pages = buf->pages; |
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struct page **page; |
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char *vpage; |
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unsigned int zero; |
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|
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if (!len) |
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return; |
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if (pgbase >= buf->page_len) { |
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xdr_buf_iov_zero(buf->tail, pgbase - buf->page_len, len); |
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return; |
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} |
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if (pgbase + len > buf->page_len) { |
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xdr_buf_iov_zero(buf->tail, 0, pgbase + len - buf->page_len); |
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len = buf->page_len - pgbase; |
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} |
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pgbase += buf->page_base; |
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page = pages + (pgbase >> PAGE_SHIFT); |
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pgbase &= ~PAGE_MASK; |
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|
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do { |
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zero = PAGE_SIZE - pgbase; |
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if (zero > len) |
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zero = len; |
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|
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vpage = kmap_atomic(*page); |
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memset(vpage + pgbase, 0, zero); |
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kunmap_atomic(vpage); |
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|
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flush_dcache_page(*page); |
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pgbase = 0; |
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page++; |
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|
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} while ((len -= zero) != 0); |
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} |
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|
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static unsigned int xdr_buf_pages_fill_sparse(const struct xdr_buf *buf, |
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unsigned int buflen, gfp_t gfp) |
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{ |
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unsigned int i, npages, pagelen; |
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|
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if (!(buf->flags & XDRBUF_SPARSE_PAGES)) |
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return buflen; |
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if (buflen <= buf->head->iov_len) |
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return buflen; |
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pagelen = buflen - buf->head->iov_len; |
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if (pagelen > buf->page_len) |
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pagelen = buf->page_len; |
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npages = (pagelen + buf->page_base + PAGE_SIZE - 1) >> PAGE_SHIFT; |
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for (i = 0; i < npages; i++) { |
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if (!buf->pages[i]) |
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continue; |
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buf->pages[i] = alloc_page(gfp); |
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if (likely(buf->pages[i])) |
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continue; |
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buflen -= pagelen; |
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pagelen = i << PAGE_SHIFT; |
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if (pagelen > buf->page_base) |
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buflen += pagelen - buf->page_base; |
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break; |
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} |
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return buflen; |
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} |
|
|
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static void xdr_buf_try_expand(struct xdr_buf *buf, unsigned int len) |
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{ |
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struct kvec *head = buf->head; |
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struct kvec *tail = buf->tail; |
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unsigned int sum = head->iov_len + buf->page_len + tail->iov_len; |
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unsigned int free_space, newlen; |
|
|
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if (sum > buf->len) { |
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free_space = min_t(unsigned int, sum - buf->len, len); |
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newlen = xdr_buf_pages_fill_sparse(buf, buf->len + free_space, |
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GFP_KERNEL); |
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free_space = newlen - buf->len; |
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buf->len = newlen; |
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len -= free_space; |
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if (!len) |
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return; |
|
} |
|
|
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if (buf->buflen > sum) { |
|
/* Expand the tail buffer */ |
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free_space = min_t(unsigned int, buf->buflen - sum, len); |
|
tail->iov_len += free_space; |
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buf->len += free_space; |
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} |
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} |
|
|
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static void xdr_buf_tail_copy_right(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
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unsigned int shift) |
|
{ |
|
const struct kvec *tail = buf->tail; |
|
unsigned int to = base + shift; |
|
|
|
if (to >= tail->iov_len) |
|
return; |
|
if (len + to > tail->iov_len) |
|
len = tail->iov_len - to; |
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memmove(tail->iov_base + to, tail->iov_base + base, len); |
|
} |
|
|
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static void xdr_buf_pages_copy_right(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
const struct kvec *tail = buf->tail; |
|
unsigned int to = base + shift; |
|
unsigned int pglen = 0; |
|
unsigned int talen = 0, tato = 0; |
|
|
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if (base >= buf->page_len) |
|
return; |
|
if (len > buf->page_len - base) |
|
len = buf->page_len - base; |
|
if (to >= buf->page_len) { |
|
tato = to - buf->page_len; |
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if (tail->iov_len >= len + tato) |
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talen = len; |
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else if (tail->iov_len > tato) |
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talen = tail->iov_len - tato; |
|
} else if (len + to >= buf->page_len) { |
|
pglen = buf->page_len - to; |
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talen = len - pglen; |
|
if (talen > tail->iov_len) |
|
talen = tail->iov_len; |
|
} else |
|
pglen = len; |
|
|
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_copy_from_pages(tail->iov_base + tato, buf->pages, |
|
buf->page_base + base + pglen, talen); |
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_shift_data_right_pages(buf->pages, buf->page_base + to, |
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buf->page_base + base, pglen); |
|
} |
|
|
|
static void xdr_buf_head_copy_right(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
const struct kvec *head = buf->head; |
|
const struct kvec *tail = buf->tail; |
|
unsigned int to = base + shift; |
|
unsigned int pglen = 0, pgto = 0; |
|
unsigned int talen = 0, tato = 0; |
|
|
|
if (base >= head->iov_len) |
|
return; |
|
if (len > head->iov_len - base) |
|
len = head->iov_len - base; |
|
if (to >= buf->page_len + head->iov_len) { |
|
tato = to - buf->page_len - head->iov_len; |
|
talen = len; |
|
} else if (to >= head->iov_len) { |
|
pgto = to - head->iov_len; |
|
pglen = len; |
|
if (pgto + pglen > buf->page_len) { |
|
talen = pgto + pglen - buf->page_len; |
|
pglen -= talen; |
|
} |
|
} else { |
|
pglen = len - to; |
|
if (pglen > buf->page_len) { |
|
talen = pglen - buf->page_len; |
|
pglen = buf->page_len; |
|
} |
|
} |
|
|
|
len -= talen; |
|
base += len; |
|
if (talen + tato > tail->iov_len) |
|
talen = tail->iov_len > tato ? tail->iov_len - tato : 0; |
|
memcpy(tail->iov_base + tato, head->iov_base + base, talen); |
|
|
|
len -= pglen; |
|
base -= pglen; |
|
_copy_to_pages(buf->pages, buf->page_base + pgto, head->iov_base + base, |
|
pglen); |
|
|
|
base -= len; |
|
memmove(head->iov_base + to, head->iov_base + base, len); |
|
} |
|
|
|
static void xdr_buf_tail_shift_right(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
const struct kvec *tail = buf->tail; |
|
|
|
if (base >= tail->iov_len || !shift || !len) |
|
return; |
|
xdr_buf_tail_copy_right(buf, base, len, shift); |
|
} |
|
|
|
static void xdr_buf_pages_shift_right(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
if (!shift || !len) |
|
return; |
|
if (base >= buf->page_len) { |
|
xdr_buf_tail_shift_right(buf, base - buf->page_len, len, shift); |
|
return; |
|
} |
|
if (base + len > buf->page_len) |
|
xdr_buf_tail_shift_right(buf, 0, base + len - buf->page_len, |
|
shift); |
|
xdr_buf_pages_copy_right(buf, base, len, shift); |
|
} |
|
|
|
static void xdr_buf_head_shift_right(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
const struct kvec *head = buf->head; |
|
|
|
if (!shift) |
|
return; |
|
if (base >= head->iov_len) { |
|
xdr_buf_pages_shift_right(buf, head->iov_len - base, len, |
|
shift); |
|
return; |
|
} |
|
if (base + len > head->iov_len) |
|
xdr_buf_pages_shift_right(buf, 0, base + len - head->iov_len, |
|
shift); |
|
xdr_buf_head_copy_right(buf, base, len, shift); |
|
} |
|
|
|
static void xdr_buf_tail_copy_left(const struct xdr_buf *buf, unsigned int base, |
|
unsigned int len, unsigned int shift) |
|
{ |
|
const struct kvec *tail = buf->tail; |
|
|
|
if (base >= tail->iov_len) |
|
return; |
|
if (len > tail->iov_len - base) |
|
len = tail->iov_len - base; |
|
/* Shift data into head */ |
|
if (shift > buf->page_len + base) { |
|
const struct kvec *head = buf->head; |
|
unsigned int hdto = |
|
head->iov_len + buf->page_len + base - shift; |
|
unsigned int hdlen = len; |
|
|
|
if (WARN_ONCE(shift > head->iov_len + buf->page_len + base, |
|
"SUNRPC: Misaligned data.\n")) |
|
return; |
|
if (hdto + hdlen > head->iov_len) |
|
hdlen = head->iov_len - hdto; |
|
memcpy(head->iov_base + hdto, tail->iov_base + base, hdlen); |
|
base += hdlen; |
|
len -= hdlen; |
|
if (!len) |
|
return; |
|
} |
|
/* Shift data into pages */ |
|
if (shift > base) { |
|
unsigned int pgto = buf->page_len + base - shift; |
|
unsigned int pglen = len; |
|
|
|
if (pgto + pglen > buf->page_len) |
|
pglen = buf->page_len - pgto; |
|
_copy_to_pages(buf->pages, buf->page_base + pgto, |
|
tail->iov_base + base, pglen); |
|
base += pglen; |
|
len -= pglen; |
|
if (!len) |
|
return; |
|
} |
|
memmove(tail->iov_base + base - shift, tail->iov_base + base, len); |
|
} |
|
|
|
static void xdr_buf_pages_copy_left(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
unsigned int pgto; |
|
|
|
if (base >= buf->page_len) |
|
return; |
|
if (len > buf->page_len - base) |
|
len = buf->page_len - base; |
|
/* Shift data into head */ |
|
if (shift > base) { |
|
const struct kvec *head = buf->head; |
|
unsigned int hdto = head->iov_len + base - shift; |
|
unsigned int hdlen = len; |
|
|
|
if (WARN_ONCE(shift > head->iov_len + base, |
|
"SUNRPC: Misaligned data.\n")) |
|
return; |
|
if (hdto + hdlen > head->iov_len) |
|
hdlen = head->iov_len - hdto; |
|
_copy_from_pages(head->iov_base + hdto, buf->pages, |
|
buf->page_base + base, hdlen); |
|
base += hdlen; |
|
len -= hdlen; |
|
if (!len) |
|
return; |
|
} |
|
pgto = base - shift; |
|
_shift_data_left_pages(buf->pages, buf->page_base + pgto, |
|
buf->page_base + base, len); |
|
} |
|
|
|
static void xdr_buf_tail_shift_left(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
if (!shift || !len) |
|
return; |
|
xdr_buf_tail_copy_left(buf, base, len, shift); |
|
} |
|
|
|
static void xdr_buf_pages_shift_left(const struct xdr_buf *buf, |
|
unsigned int base, unsigned int len, |
|
unsigned int shift) |
|
{ |
|
if (!shift || !len) |
|
return; |
|
if (base >= buf->page_len) { |
|
xdr_buf_tail_shift_left(buf, base - buf->page_len, len, shift); |
|
return; |
|
} |
|
xdr_buf_pages_copy_left(buf, base, len, shift); |
|
len += base; |
|
if (len <= buf->page_len) |
|
return; |
|
xdr_buf_tail_copy_left(buf, 0, len - buf->page_len, shift); |
|
} |
|
|
|
/** |
|
* xdr_shrink_bufhead |
|
* @buf: xdr_buf |
|
* @len: new length of buf->head[0] |
|
* |
|
* Shrinks XDR buffer's header kvec buf->head[0], setting it to |
|
* 'len' bytes. The extra data is not lost, but is instead |
|
* moved into the inlined pages and/or the tail. |
|
*/ |
|
static unsigned int xdr_shrink_bufhead(struct xdr_buf *buf, unsigned int len) |
|
{ |
|
struct kvec *head = buf->head; |
|
unsigned int shift, buflen = max(buf->len, len); |
|
|
|
WARN_ON_ONCE(len > head->iov_len); |
|
if (head->iov_len > buflen) { |
|
buf->buflen -= head->iov_len - buflen; |
|
head->iov_len = buflen; |
|
} |
|
if (len >= head->iov_len) |
|
return 0; |
|
shift = head->iov_len - len; |
|
xdr_buf_try_expand(buf, shift); |
|
xdr_buf_head_shift_right(buf, len, buflen - len, shift); |
|
head->iov_len = len; |
|
buf->buflen -= shift; |
|
buf->len -= shift; |
|
return shift; |
|
} |
|
|
|
/** |
|
* xdr_shrink_pagelen - shrinks buf->pages to @len bytes |
|
* @buf: xdr_buf |
|
* @len: new page buffer length |
|
* |
|
* The extra data is not lost, but is instead moved into buf->tail. |
|
* Returns the actual number of bytes moved. |
|
*/ |
|
static unsigned int xdr_shrink_pagelen(struct xdr_buf *buf, unsigned int len) |
|
{ |
|
unsigned int shift, buflen = buf->len - buf->head->iov_len; |
|
|
|
WARN_ON_ONCE(len > buf->page_len); |
|
if (buf->head->iov_len >= buf->len || len > buflen) |
|
buflen = len; |
|
if (buf->page_len > buflen) { |
|
buf->buflen -= buf->page_len - buflen; |
|
buf->page_len = buflen; |
|
} |
|
if (len >= buf->page_len) |
|
return 0; |
|
shift = buf->page_len - len; |
|
xdr_buf_try_expand(buf, shift); |
|
xdr_buf_pages_shift_right(buf, len, buflen - len, shift); |
|
buf->page_len = len; |
|
buf->len -= shift; |
|
buf->buflen -= shift; |
|
return shift; |
|
} |
|
|
|
void |
|
xdr_shift_buf(struct xdr_buf *buf, size_t len) |
|
{ |
|
xdr_shrink_bufhead(buf, buf->head->iov_len - len); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_shift_buf); |
|
|
|
/** |
|
* xdr_stream_pos - Return the current offset from the start of the xdr_stream |
|
* @xdr: pointer to struct xdr_stream |
|
*/ |
|
unsigned int xdr_stream_pos(const struct xdr_stream *xdr) |
|
{ |
|
return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_stream_pos); |
|
|
|
static void xdr_stream_set_pos(struct xdr_stream *xdr, unsigned int pos) |
|
{ |
|
unsigned int blen = xdr->buf->len; |
|
|
|
xdr->nwords = blen > pos ? XDR_QUADLEN(blen) - XDR_QUADLEN(pos) : 0; |
|
} |
|
|
|
static void xdr_stream_page_set_pos(struct xdr_stream *xdr, unsigned int pos) |
|
{ |
|
xdr_stream_set_pos(xdr, pos + xdr->buf->head[0].iov_len); |
|
} |
|
|
|
/** |
|
* xdr_page_pos - Return the current offset from the start of the xdr pages |
|
* @xdr: pointer to struct xdr_stream |
|
*/ |
|
unsigned int xdr_page_pos(const struct xdr_stream *xdr) |
|
{ |
|
unsigned int pos = xdr_stream_pos(xdr); |
|
|
|
WARN_ON(pos < xdr->buf->head[0].iov_len); |
|
return pos - xdr->buf->head[0].iov_len; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_page_pos); |
|
|
|
/** |
|
* xdr_init_encode - Initialize a struct xdr_stream for sending data. |
|
* @xdr: pointer to xdr_stream struct |
|
* @buf: pointer to XDR buffer in which to encode data |
|
* @p: current pointer inside XDR buffer |
|
* @rqst: pointer to controlling rpc_rqst, for debugging |
|
* |
|
* Note: at the moment the RPC client only passes the length of our |
|
* scratch buffer in the xdr_buf's header kvec. Previously this |
|
* meant we needed to call xdr_adjust_iovec() after encoding the |
|
* data. With the new scheme, the xdr_stream manages the details |
|
* of the buffer length, and takes care of adjusting the kvec |
|
* length for us. |
|
*/ |
|
void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
|
struct rpc_rqst *rqst) |
|
{ |
|
struct kvec *iov = buf->head; |
|
int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len; |
|
|
|
xdr_reset_scratch_buffer(xdr); |
|
BUG_ON(scratch_len < 0); |
|
xdr->buf = buf; |
|
xdr->iov = iov; |
|
xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len); |
|
xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len); |
|
BUG_ON(iov->iov_len > scratch_len); |
|
|
|
if (p != xdr->p && p != NULL) { |
|
size_t len; |
|
|
|
BUG_ON(p < xdr->p || p > xdr->end); |
|
len = (char *)p - (char *)xdr->p; |
|
xdr->p = p; |
|
buf->len += len; |
|
iov->iov_len += len; |
|
} |
|
xdr->rqst = rqst; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_init_encode); |
|
|
|
/** |
|
* xdr_commit_encode - Ensure all data is written to buffer |
|
* @xdr: pointer to xdr_stream |
|
* |
|
* We handle encoding across page boundaries by giving the caller a |
|
* temporary location to write to, then later copying the data into |
|
* place; xdr_commit_encode does that copying. |
|
* |
|
* Normally the caller doesn't need to call this directly, as the |
|
* following xdr_reserve_space will do it. But an explicit call may be |
|
* required at the end of encoding, or any other time when the xdr_buf |
|
* data might be read. |
|
*/ |
|
inline void xdr_commit_encode(struct xdr_stream *xdr) |
|
{ |
|
int shift = xdr->scratch.iov_len; |
|
void *page; |
|
|
|
if (shift == 0) |
|
return; |
|
page = page_address(*xdr->page_ptr); |
|
memcpy(xdr->scratch.iov_base, page, shift); |
|
memmove(page, page + shift, (void *)xdr->p - page); |
|
xdr_reset_scratch_buffer(xdr); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_commit_encode); |
|
|
|
static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, |
|
size_t nbytes) |
|
{ |
|
__be32 *p; |
|
int space_left; |
|
int frag1bytes, frag2bytes; |
|
|
|
if (nbytes > PAGE_SIZE) |
|
goto out_overflow; /* Bigger buffers require special handling */ |
|
if (xdr->buf->len + nbytes > xdr->buf->buflen) |
|
goto out_overflow; /* Sorry, we're totally out of space */ |
|
frag1bytes = (xdr->end - xdr->p) << 2; |
|
frag2bytes = nbytes - frag1bytes; |
|
if (xdr->iov) |
|
xdr->iov->iov_len += frag1bytes; |
|
else |
|
xdr->buf->page_len += frag1bytes; |
|
xdr->page_ptr++; |
|
xdr->iov = NULL; |
|
/* |
|
* If the last encode didn't end exactly on a page boundary, the |
|
* next one will straddle boundaries. Encode into the next |
|
* page, then copy it back later in xdr_commit_encode. We use |
|
* the "scratch" iov to track any temporarily unused fragment of |
|
* space at the end of the previous buffer: |
|
*/ |
|
xdr_set_scratch_buffer(xdr, xdr->p, frag1bytes); |
|
p = page_address(*xdr->page_ptr); |
|
/* |
|
* Note this is where the next encode will start after we've |
|
* shifted this one back: |
|
*/ |
|
xdr->p = (void *)p + frag2bytes; |
|
space_left = xdr->buf->buflen - xdr->buf->len; |
|
xdr->end = (void *)p + min_t(int, space_left, PAGE_SIZE); |
|
xdr->buf->page_len += frag2bytes; |
|
xdr->buf->len += nbytes; |
|
return p; |
|
out_overflow: |
|
trace_rpc_xdr_overflow(xdr, nbytes); |
|
return NULL; |
|
} |
|
|
|
/** |
|
* xdr_reserve_space - Reserve buffer space for sending |
|
* @xdr: pointer to xdr_stream |
|
* @nbytes: number of bytes to reserve |
|
* |
|
* Checks that we have enough buffer space to encode 'nbytes' more |
|
* bytes of data. If so, update the total xdr_buf length, and |
|
* adjust the length of the current kvec. |
|
*/ |
|
__be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes) |
|
{ |
|
__be32 *p = xdr->p; |
|
__be32 *q; |
|
|
|
xdr_commit_encode(xdr); |
|
/* align nbytes on the next 32-bit boundary */ |
|
nbytes += 3; |
|
nbytes &= ~3; |
|
q = p + (nbytes >> 2); |
|
if (unlikely(q > xdr->end || q < p)) |
|
return xdr_get_next_encode_buffer(xdr, nbytes); |
|
xdr->p = q; |
|
if (xdr->iov) |
|
xdr->iov->iov_len += nbytes; |
|
else |
|
xdr->buf->page_len += nbytes; |
|
xdr->buf->len += nbytes; |
|
return p; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_reserve_space); |
|
|
|
|
|
/** |
|
* xdr_reserve_space_vec - Reserves a large amount of buffer space for sending |
|
* @xdr: pointer to xdr_stream |
|
* @vec: pointer to a kvec array |
|
* @nbytes: number of bytes to reserve |
|
* |
|
* Reserves enough buffer space to encode 'nbytes' of data and stores the |
|
* pointers in 'vec'. The size argument passed to xdr_reserve_space() is |
|
* determined based on the number of bytes remaining in the current page to |
|
* avoid invalidating iov_base pointers when xdr_commit_encode() is called. |
|
*/ |
|
int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbytes) |
|
{ |
|
int thislen; |
|
int v = 0; |
|
__be32 *p; |
|
|
|
/* |
|
* svcrdma requires every READ payload to start somewhere |
|
* in xdr->pages. |
|
*/ |
|
if (xdr->iov == xdr->buf->head) { |
|
xdr->iov = NULL; |
|
xdr->end = xdr->p; |
|
} |
|
|
|
while (nbytes) { |
|
thislen = xdr->buf->page_len % PAGE_SIZE; |
|
thislen = min_t(size_t, nbytes, PAGE_SIZE - thislen); |
|
|
|
p = xdr_reserve_space(xdr, thislen); |
|
if (!p) |
|
return -EIO; |
|
|
|
vec[v].iov_base = p; |
|
vec[v].iov_len = thislen; |
|
v++; |
|
nbytes -= thislen; |
|
} |
|
|
|
return v; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_reserve_space_vec); |
|
|
|
/** |
|
* xdr_truncate_encode - truncate an encode buffer |
|
* @xdr: pointer to xdr_stream |
|
* @len: new length of buffer |
|
* |
|
* Truncates the xdr stream, so that xdr->buf->len == len, |
|
* and xdr->p points at offset len from the start of the buffer, and |
|
* head, tail, and page lengths are adjusted to correspond. |
|
* |
|
* If this means moving xdr->p to a different buffer, we assume that |
|
* the end pointer should be set to the end of the current page, |
|
* except in the case of the head buffer when we assume the head |
|
* buffer's current length represents the end of the available buffer. |
|
* |
|
* This is *not* safe to use on a buffer that already has inlined page |
|
* cache pages (as in a zero-copy server read reply), except for the |
|
* simple case of truncating from one position in the tail to another. |
|
* |
|
*/ |
|
void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
struct kvec *head = buf->head; |
|
struct kvec *tail = buf->tail; |
|
int fraglen; |
|
int new; |
|
|
|
if (len > buf->len) { |
|
WARN_ON_ONCE(1); |
|
return; |
|
} |
|
xdr_commit_encode(xdr); |
|
|
|
fraglen = min_t(int, buf->len - len, tail->iov_len); |
|
tail->iov_len -= fraglen; |
|
buf->len -= fraglen; |
|
if (tail->iov_len) { |
|
xdr->p = tail->iov_base + tail->iov_len; |
|
WARN_ON_ONCE(!xdr->end); |
|
WARN_ON_ONCE(!xdr->iov); |
|
return; |
|
} |
|
WARN_ON_ONCE(fraglen); |
|
fraglen = min_t(int, buf->len - len, buf->page_len); |
|
buf->page_len -= fraglen; |
|
buf->len -= fraglen; |
|
|
|
new = buf->page_base + buf->page_len; |
|
|
|
xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT); |
|
|
|
if (buf->page_len) { |
|
xdr->p = page_address(*xdr->page_ptr); |
|
xdr->end = (void *)xdr->p + PAGE_SIZE; |
|
xdr->p = (void *)xdr->p + (new % PAGE_SIZE); |
|
WARN_ON_ONCE(xdr->iov); |
|
return; |
|
} |
|
if (fraglen) |
|
xdr->end = head->iov_base + head->iov_len; |
|
/* (otherwise assume xdr->end is already set) */ |
|
xdr->page_ptr--; |
|
head->iov_len = len; |
|
buf->len = len; |
|
xdr->p = head->iov_base + head->iov_len; |
|
xdr->iov = buf->head; |
|
} |
|
EXPORT_SYMBOL(xdr_truncate_encode); |
|
|
|
/** |
|
* xdr_restrict_buflen - decrease available buffer space |
|
* @xdr: pointer to xdr_stream |
|
* @newbuflen: new maximum number of bytes available |
|
* |
|
* Adjust our idea of how much space is available in the buffer. |
|
* If we've already used too much space in the buffer, returns -1. |
|
* If the available space is already smaller than newbuflen, returns 0 |
|
* and does nothing. Otherwise, adjusts xdr->buf->buflen to newbuflen |
|
* and ensures xdr->end is set at most offset newbuflen from the start |
|
* of the buffer. |
|
*/ |
|
int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
int left_in_this_buf = (void *)xdr->end - (void *)xdr->p; |
|
int end_offset = buf->len + left_in_this_buf; |
|
|
|
if (newbuflen < 0 || newbuflen < buf->len) |
|
return -1; |
|
if (newbuflen > buf->buflen) |
|
return 0; |
|
if (newbuflen < end_offset) |
|
xdr->end = (void *)xdr->end + newbuflen - end_offset; |
|
buf->buflen = newbuflen; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(xdr_restrict_buflen); |
|
|
|
/** |
|
* xdr_write_pages - Insert a list of pages into an XDR buffer for sending |
|
* @xdr: pointer to xdr_stream |
|
* @pages: list of pages |
|
* @base: offset of first byte |
|
* @len: length of data in bytes |
|
* |
|
*/ |
|
void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, |
|
unsigned int len) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
struct kvec *iov = buf->tail; |
|
buf->pages = pages; |
|
buf->page_base = base; |
|
buf->page_len = len; |
|
|
|
iov->iov_base = (char *)xdr->p; |
|
iov->iov_len = 0; |
|
xdr->iov = iov; |
|
|
|
if (len & 3) { |
|
unsigned int pad = 4 - (len & 3); |
|
|
|
BUG_ON(xdr->p >= xdr->end); |
|
iov->iov_base = (char *)xdr->p + (len & 3); |
|
iov->iov_len += pad; |
|
len += pad; |
|
*xdr->p++ = 0; |
|
} |
|
buf->buflen += len; |
|
buf->len += len; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_write_pages); |
|
|
|
static unsigned int xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov, |
|
unsigned int base, unsigned int len) |
|
{ |
|
if (len > iov->iov_len) |
|
len = iov->iov_len; |
|
if (unlikely(base > len)) |
|
base = len; |
|
xdr->p = (__be32*)(iov->iov_base + base); |
|
xdr->end = (__be32*)(iov->iov_base + len); |
|
xdr->iov = iov; |
|
xdr->page_ptr = NULL; |
|
return len - base; |
|
} |
|
|
|
static unsigned int xdr_set_tail_base(struct xdr_stream *xdr, |
|
unsigned int base, unsigned int len) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
|
|
xdr_stream_set_pos(xdr, base + buf->page_len + buf->head->iov_len); |
|
return xdr_set_iov(xdr, buf->tail, base, len); |
|
} |
|
|
|
static unsigned int xdr_set_page_base(struct xdr_stream *xdr, |
|
unsigned int base, unsigned int len) |
|
{ |
|
unsigned int pgnr; |
|
unsigned int maxlen; |
|
unsigned int pgoff; |
|
unsigned int pgend; |
|
void *kaddr; |
|
|
|
maxlen = xdr->buf->page_len; |
|
if (base >= maxlen) |
|
return 0; |
|
else |
|
maxlen -= base; |
|
if (len > maxlen) |
|
len = maxlen; |
|
|
|
xdr_stream_page_set_pos(xdr, base); |
|
base += xdr->buf->page_base; |
|
|
|
pgnr = base >> PAGE_SHIFT; |
|
xdr->page_ptr = &xdr->buf->pages[pgnr]; |
|
kaddr = page_address(*xdr->page_ptr); |
|
|
|
pgoff = base & ~PAGE_MASK; |
|
xdr->p = (__be32*)(kaddr + pgoff); |
|
|
|
pgend = pgoff + len; |
|
if (pgend > PAGE_SIZE) |
|
pgend = PAGE_SIZE; |
|
xdr->end = (__be32*)(kaddr + pgend); |
|
xdr->iov = NULL; |
|
return len; |
|
} |
|
|
|
static void xdr_set_page(struct xdr_stream *xdr, unsigned int base, |
|
unsigned int len) |
|
{ |
|
if (xdr_set_page_base(xdr, base, len) == 0) { |
|
base -= xdr->buf->page_len; |
|
xdr_set_tail_base(xdr, base, len); |
|
} |
|
} |
|
|
|
static void xdr_set_next_page(struct xdr_stream *xdr) |
|
{ |
|
unsigned int newbase; |
|
|
|
newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT; |
|
newbase -= xdr->buf->page_base; |
|
if (newbase < xdr->buf->page_len) |
|
xdr_set_page_base(xdr, newbase, xdr_stream_remaining(xdr)); |
|
else |
|
xdr_set_tail_base(xdr, 0, xdr_stream_remaining(xdr)); |
|
} |
|
|
|
static bool xdr_set_next_buffer(struct xdr_stream *xdr) |
|
{ |
|
if (xdr->page_ptr != NULL) |
|
xdr_set_next_page(xdr); |
|
else if (xdr->iov == xdr->buf->head) |
|
xdr_set_page(xdr, 0, xdr_stream_remaining(xdr)); |
|
return xdr->p != xdr->end; |
|
} |
|
|
|
/** |
|
* xdr_init_decode - Initialize an xdr_stream for decoding data. |
|
* @xdr: pointer to xdr_stream struct |
|
* @buf: pointer to XDR buffer from which to decode data |
|
* @p: current pointer inside XDR buffer |
|
* @rqst: pointer to controlling rpc_rqst, for debugging |
|
*/ |
|
void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
|
struct rpc_rqst *rqst) |
|
{ |
|
xdr->buf = buf; |
|
xdr_reset_scratch_buffer(xdr); |
|
xdr->nwords = XDR_QUADLEN(buf->len); |
|
if (xdr_set_iov(xdr, buf->head, 0, buf->len) == 0 && |
|
xdr_set_page_base(xdr, 0, buf->len) == 0) |
|
xdr_set_iov(xdr, buf->tail, 0, buf->len); |
|
if (p != NULL && p > xdr->p && xdr->end >= p) { |
|
xdr->nwords -= p - xdr->p; |
|
xdr->p = p; |
|
} |
|
xdr->rqst = rqst; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_init_decode); |
|
|
|
/** |
|
* xdr_init_decode_pages - Initialize an xdr_stream for decoding into pages |
|
* @xdr: pointer to xdr_stream struct |
|
* @buf: pointer to XDR buffer from which to decode data |
|
* @pages: list of pages to decode into |
|
* @len: length in bytes of buffer in pages |
|
*/ |
|
void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, |
|
struct page **pages, unsigned int len) |
|
{ |
|
memset(buf, 0, sizeof(*buf)); |
|
buf->pages = pages; |
|
buf->page_len = len; |
|
buf->buflen = len; |
|
buf->len = len; |
|
xdr_init_decode(xdr, buf, NULL, NULL); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_init_decode_pages); |
|
|
|
static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
|
{ |
|
unsigned int nwords = XDR_QUADLEN(nbytes); |
|
__be32 *p = xdr->p; |
|
__be32 *q = p + nwords; |
|
|
|
if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p)) |
|
return NULL; |
|
xdr->p = q; |
|
xdr->nwords -= nwords; |
|
return p; |
|
} |
|
|
|
static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes) |
|
{ |
|
__be32 *p; |
|
char *cpdest = xdr->scratch.iov_base; |
|
size_t cplen = (char *)xdr->end - (char *)xdr->p; |
|
|
|
if (nbytes > xdr->scratch.iov_len) |
|
goto out_overflow; |
|
p = __xdr_inline_decode(xdr, cplen); |
|
if (p == NULL) |
|
return NULL; |
|
memcpy(cpdest, p, cplen); |
|
if (!xdr_set_next_buffer(xdr)) |
|
goto out_overflow; |
|
cpdest += cplen; |
|
nbytes -= cplen; |
|
p = __xdr_inline_decode(xdr, nbytes); |
|
if (p == NULL) |
|
return NULL; |
|
memcpy(cpdest, p, nbytes); |
|
return xdr->scratch.iov_base; |
|
out_overflow: |
|
trace_rpc_xdr_overflow(xdr, nbytes); |
|
return NULL; |
|
} |
|
|
|
/** |
|
* xdr_inline_decode - Retrieve XDR data to decode |
|
* @xdr: pointer to xdr_stream struct |
|
* @nbytes: number of bytes of data to decode |
|
* |
|
* Check if the input buffer is long enough to enable us to decode |
|
* 'nbytes' more bytes of data starting at the current position. |
|
* If so return the current pointer, then update the current |
|
* pointer position. |
|
*/ |
|
__be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
|
{ |
|
__be32 *p; |
|
|
|
if (unlikely(nbytes == 0)) |
|
return xdr->p; |
|
if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr)) |
|
goto out_overflow; |
|
p = __xdr_inline_decode(xdr, nbytes); |
|
if (p != NULL) |
|
return p; |
|
return xdr_copy_to_scratch(xdr, nbytes); |
|
out_overflow: |
|
trace_rpc_xdr_overflow(xdr, nbytes); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_inline_decode); |
|
|
|
static void xdr_realign_pages(struct xdr_stream *xdr) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
struct kvec *iov = buf->head; |
|
unsigned int cur = xdr_stream_pos(xdr); |
|
unsigned int copied; |
|
|
|
/* Realign pages to current pointer position */ |
|
if (iov->iov_len > cur) { |
|
copied = xdr_shrink_bufhead(buf, cur); |
|
trace_rpc_xdr_alignment(xdr, cur, copied); |
|
xdr_set_page(xdr, 0, buf->page_len); |
|
} |
|
} |
|
|
|
static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
unsigned int nwords = XDR_QUADLEN(len); |
|
unsigned int copied; |
|
|
|
if (xdr->nwords == 0) |
|
return 0; |
|
|
|
xdr_realign_pages(xdr); |
|
if (nwords > xdr->nwords) { |
|
nwords = xdr->nwords; |
|
len = nwords << 2; |
|
} |
|
if (buf->page_len <= len) |
|
len = buf->page_len; |
|
else if (nwords < xdr->nwords) { |
|
/* Truncate page data and move it into the tail */ |
|
copied = xdr_shrink_pagelen(buf, len); |
|
trace_rpc_xdr_alignment(xdr, len, copied); |
|
} |
|
return len; |
|
} |
|
|
|
/** |
|
* xdr_read_pages - align page-based XDR data to current pointer position |
|
* @xdr: pointer to xdr_stream struct |
|
* @len: number of bytes of page data |
|
* |
|
* Moves data beyond the current pointer position from the XDR head[] buffer |
|
* into the page list. Any data that lies beyond current position + @len |
|
* bytes is moved into the XDR tail[]. The xdr_stream current position is |
|
* then advanced past that data to align to the next XDR object in the tail. |
|
* |
|
* Returns the number of XDR encoded bytes now contained in the pages |
|
*/ |
|
unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) |
|
{ |
|
unsigned int nwords = XDR_QUADLEN(len); |
|
unsigned int base, end, pglen; |
|
|
|
pglen = xdr_align_pages(xdr, nwords << 2); |
|
if (pglen == 0) |
|
return 0; |
|
|
|
base = (nwords << 2) - pglen; |
|
end = xdr_stream_remaining(xdr) - pglen; |
|
|
|
xdr_set_tail_base(xdr, base, end); |
|
return len <= pglen ? len : pglen; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_read_pages); |
|
|
|
unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset, |
|
unsigned int length) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
unsigned int from, bytes, len; |
|
unsigned int shift; |
|
|
|
xdr_realign_pages(xdr); |
|
from = xdr_page_pos(xdr); |
|
|
|
if (from >= buf->page_len + buf->tail->iov_len) |
|
return 0; |
|
if (from + buf->head->iov_len >= buf->len) |
|
return 0; |
|
|
|
len = buf->len - buf->head->iov_len; |
|
|
|
/* We only shift data left! */ |
|
if (WARN_ONCE(from < offset, "SUNRPC: misaligned data src=%u dst=%u\n", |
|
from, offset)) |
|
return 0; |
|
if (WARN_ONCE(offset > buf->page_len, |
|
"SUNRPC: buffer overflow. offset=%u, page_len=%u\n", |
|
offset, buf->page_len)) |
|
return 0; |
|
|
|
/* Move page data to the left */ |
|
shift = from - offset; |
|
xdr_buf_pages_shift_left(buf, from, len, shift); |
|
|
|
bytes = xdr_stream_remaining(xdr); |
|
if (length > bytes) |
|
length = bytes; |
|
bytes -= length; |
|
|
|
xdr->buf->len -= shift; |
|
xdr_set_page(xdr, offset + length, bytes); |
|
return length; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_align_data); |
|
|
|
unsigned int xdr_expand_hole(struct xdr_stream *xdr, unsigned int offset, |
|
unsigned int length) |
|
{ |
|
struct xdr_buf *buf = xdr->buf; |
|
unsigned int from, to, shift; |
|
|
|
xdr_realign_pages(xdr); |
|
from = xdr_page_pos(xdr); |
|
to = xdr_align_size(offset + length); |
|
|
|
/* Could the hole be behind us? */ |
|
if (to > from) { |
|
unsigned int buflen = buf->len - buf->head->iov_len; |
|
shift = to - from; |
|
xdr_buf_try_expand(buf, shift); |
|
xdr_buf_pages_shift_right(buf, from, buflen, shift); |
|
xdr_set_page(xdr, to, xdr_stream_remaining(xdr)); |
|
} else if (to != from) |
|
xdr_align_data(xdr, to, 0); |
|
xdr_buf_pages_zero(buf, offset, length); |
|
|
|
return length; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_expand_hole); |
|
|
|
/** |
|
* xdr_enter_page - decode data from the XDR page |
|
* @xdr: pointer to xdr_stream struct |
|
* @len: number of bytes of page data |
|
* |
|
* Moves data beyond the current pointer position from the XDR head[] buffer |
|
* into the page list. Any data that lies beyond current position + "len" |
|
* bytes is moved into the XDR tail[]. The current pointer is then |
|
* repositioned at the beginning of the first XDR page. |
|
*/ |
|
void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) |
|
{ |
|
len = xdr_align_pages(xdr, len); |
|
/* |
|
* Position current pointer at beginning of tail, and |
|
* set remaining message length. |
|
*/ |
|
if (len != 0) |
|
xdr_set_page_base(xdr, 0, len); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_enter_page); |
|
|
|
static const struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0}; |
|
|
|
void xdr_buf_from_iov(const struct kvec *iov, struct xdr_buf *buf) |
|
{ |
|
buf->head[0] = *iov; |
|
buf->tail[0] = empty_iov; |
|
buf->page_len = 0; |
|
buf->buflen = buf->len = iov->iov_len; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_buf_from_iov); |
|
|
|
/** |
|
* xdr_buf_subsegment - set subbuf to a portion of buf |
|
* @buf: an xdr buffer |
|
* @subbuf: the result buffer |
|
* @base: beginning of range in bytes |
|
* @len: length of range in bytes |
|
* |
|
* sets @subbuf to an xdr buffer representing the portion of @buf of |
|
* length @len starting at offset @base. |
|
* |
|
* @buf and @subbuf may be pointers to the same struct xdr_buf. |
|
* |
|
* Returns -1 if base of length are out of bounds. |
|
*/ |
|
int xdr_buf_subsegment(const struct xdr_buf *buf, struct xdr_buf *subbuf, |
|
unsigned int base, unsigned int len) |
|
{ |
|
subbuf->buflen = subbuf->len = len; |
|
if (base < buf->head[0].iov_len) { |
|
subbuf->head[0].iov_base = buf->head[0].iov_base + base; |
|
subbuf->head[0].iov_len = min_t(unsigned int, len, |
|
buf->head[0].iov_len - base); |
|
len -= subbuf->head[0].iov_len; |
|
base = 0; |
|
} else { |
|
base -= buf->head[0].iov_len; |
|
subbuf->head[0].iov_base = buf->head[0].iov_base; |
|
subbuf->head[0].iov_len = 0; |
|
} |
|
|
|
if (base < buf->page_len) { |
|
subbuf->page_len = min(buf->page_len - base, len); |
|
base += buf->page_base; |
|
subbuf->page_base = base & ~PAGE_MASK; |
|
subbuf->pages = &buf->pages[base >> PAGE_SHIFT]; |
|
len -= subbuf->page_len; |
|
base = 0; |
|
} else { |
|
base -= buf->page_len; |
|
subbuf->pages = buf->pages; |
|
subbuf->page_base = 0; |
|
subbuf->page_len = 0; |
|
} |
|
|
|
if (base < buf->tail[0].iov_len) { |
|
subbuf->tail[0].iov_base = buf->tail[0].iov_base + base; |
|
subbuf->tail[0].iov_len = min_t(unsigned int, len, |
|
buf->tail[0].iov_len - base); |
|
len -= subbuf->tail[0].iov_len; |
|
base = 0; |
|
} else { |
|
base -= buf->tail[0].iov_len; |
|
subbuf->tail[0].iov_base = buf->tail[0].iov_base; |
|
subbuf->tail[0].iov_len = 0; |
|
} |
|
|
|
if (base || len) |
|
return -1; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_buf_subsegment); |
|
|
|
/** |
|
* xdr_stream_subsegment - set @subbuf to a portion of @xdr |
|
* @xdr: an xdr_stream set up for decoding |
|
* @subbuf: the result buffer |
|
* @nbytes: length of @xdr to extract, in bytes |
|
* |
|
* Sets up @subbuf to represent a portion of @xdr. The portion |
|
* starts at the current offset in @xdr, and extends for a length |
|
* of @nbytes. If this is successful, @xdr is advanced to the next |
|
* XDR data item following that portion. |
|
* |
|
* Return values: |
|
* %true: @subbuf has been initialized, and @xdr has been advanced. |
|
* %false: a bounds error has occurred |
|
*/ |
|
bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf, |
|
unsigned int nbytes) |
|
{ |
|
unsigned int start = xdr_stream_pos(xdr); |
|
unsigned int remaining, len; |
|
|
|
/* Extract @subbuf and bounds-check the fn arguments */ |
|
if (xdr_buf_subsegment(xdr->buf, subbuf, start, nbytes)) |
|
return false; |
|
|
|
/* Advance @xdr by @nbytes */ |
|
for (remaining = nbytes; remaining;) { |
|
if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr)) |
|
return false; |
|
|
|
len = (char *)xdr->end - (char *)xdr->p; |
|
if (remaining <= len) { |
|
xdr->p = (__be32 *)((char *)xdr->p + |
|
(remaining + xdr_pad_size(nbytes))); |
|
break; |
|
} |
|
|
|
xdr->p = (__be32 *)((char *)xdr->p + len); |
|
xdr->end = xdr->p; |
|
remaining -= len; |
|
} |
|
|
|
xdr_stream_set_pos(xdr, start + nbytes); |
|
return true; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_stream_subsegment); |
|
|
|
/** |
|
* xdr_buf_trim - lop at most "len" bytes off the end of "buf" |
|
* @buf: buf to be trimmed |
|
* @len: number of bytes to reduce "buf" by |
|
* |
|
* Trim an xdr_buf by the given number of bytes by fixing up the lengths. Note |
|
* that it's possible that we'll trim less than that amount if the xdr_buf is |
|
* too small, or if (for instance) it's all in the head and the parser has |
|
* already read too far into it. |
|
*/ |
|
void xdr_buf_trim(struct xdr_buf *buf, unsigned int len) |
|
{ |
|
size_t cur; |
|
unsigned int trim = len; |
|
|
|
if (buf->tail[0].iov_len) { |
|
cur = min_t(size_t, buf->tail[0].iov_len, trim); |
|
buf->tail[0].iov_len -= cur; |
|
trim -= cur; |
|
if (!trim) |
|
goto fix_len; |
|
} |
|
|
|
if (buf->page_len) { |
|
cur = min_t(unsigned int, buf->page_len, trim); |
|
buf->page_len -= cur; |
|
trim -= cur; |
|
if (!trim) |
|
goto fix_len; |
|
} |
|
|
|
if (buf->head[0].iov_len) { |
|
cur = min_t(size_t, buf->head[0].iov_len, trim); |
|
buf->head[0].iov_len -= cur; |
|
trim -= cur; |
|
} |
|
fix_len: |
|
buf->len -= (len - trim); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_buf_trim); |
|
|
|
static void __read_bytes_from_xdr_buf(const struct xdr_buf *subbuf, |
|
void *obj, unsigned int len) |
|
{ |
|
unsigned int this_len; |
|
|
|
this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
|
memcpy(obj, subbuf->head[0].iov_base, this_len); |
|
len -= this_len; |
|
obj += this_len; |
|
this_len = min_t(unsigned int, len, subbuf->page_len); |
|
_copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len); |
|
len -= this_len; |
|
obj += this_len; |
|
this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
|
memcpy(obj, subbuf->tail[0].iov_base, this_len); |
|
} |
|
|
|
/* obj is assumed to point to allocated memory of size at least len: */ |
|
int read_bytes_from_xdr_buf(const struct xdr_buf *buf, unsigned int base, |
|
void *obj, unsigned int len) |
|
{ |
|
struct xdr_buf subbuf; |
|
int status; |
|
|
|
status = xdr_buf_subsegment(buf, &subbuf, base, len); |
|
if (status != 0) |
|
return status; |
|
__read_bytes_from_xdr_buf(&subbuf, obj, len); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf); |
|
|
|
static void __write_bytes_to_xdr_buf(const struct xdr_buf *subbuf, |
|
void *obj, unsigned int len) |
|
{ |
|
unsigned int this_len; |
|
|
|
this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
|
memcpy(subbuf->head[0].iov_base, obj, this_len); |
|
len -= this_len; |
|
obj += this_len; |
|
this_len = min_t(unsigned int, len, subbuf->page_len); |
|
_copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len); |
|
len -= this_len; |
|
obj += this_len; |
|
this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
|
memcpy(subbuf->tail[0].iov_base, obj, this_len); |
|
} |
|
|
|
/* obj is assumed to point to allocated memory of size at least len: */ |
|
int write_bytes_to_xdr_buf(const struct xdr_buf *buf, unsigned int base, |
|
void *obj, unsigned int len) |
|
{ |
|
struct xdr_buf subbuf; |
|
int status; |
|
|
|
status = xdr_buf_subsegment(buf, &subbuf, base, len); |
|
if (status != 0) |
|
return status; |
|
__write_bytes_to_xdr_buf(&subbuf, obj, len); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf); |
|
|
|
int xdr_decode_word(const struct xdr_buf *buf, unsigned int base, u32 *obj) |
|
{ |
|
__be32 raw; |
|
int status; |
|
|
|
status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); |
|
if (status) |
|
return status; |
|
*obj = be32_to_cpu(raw); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_decode_word); |
|
|
|
int xdr_encode_word(const struct xdr_buf *buf, unsigned int base, u32 obj) |
|
{ |
|
__be32 raw = cpu_to_be32(obj); |
|
|
|
return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj)); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_encode_word); |
|
|
|
/* Returns 0 on success, or else a negative error code. */ |
|
static int xdr_xcode_array2(const struct xdr_buf *buf, unsigned int base, |
|
struct xdr_array2_desc *desc, int encode) |
|
{ |
|
char *elem = NULL, *c; |
|
unsigned int copied = 0, todo, avail_here; |
|
struct page **ppages = NULL; |
|
int err; |
|
|
|
if (encode) { |
|
if (xdr_encode_word(buf, base, desc->array_len) != 0) |
|
return -EINVAL; |
|
} else { |
|
if (xdr_decode_word(buf, base, &desc->array_len) != 0 || |
|
desc->array_len > desc->array_maxlen || |
|
(unsigned long) base + 4 + desc->array_len * |
|
desc->elem_size > buf->len) |
|
return -EINVAL; |
|
} |
|
base += 4; |
|
|
|
if (!desc->xcode) |
|
return 0; |
|
|
|
todo = desc->array_len * desc->elem_size; |
|
|
|
/* process head */ |
|
if (todo && base < buf->head->iov_len) { |
|
c = buf->head->iov_base + base; |
|
avail_here = min_t(unsigned int, todo, |
|
buf->head->iov_len - base); |
|
todo -= avail_here; |
|
|
|
while (avail_here >= desc->elem_size) { |
|
err = desc->xcode(desc, c); |
|
if (err) |
|
goto out; |
|
c += desc->elem_size; |
|
avail_here -= desc->elem_size; |
|
} |
|
if (avail_here) { |
|
if (!elem) { |
|
elem = kmalloc(desc->elem_size, GFP_KERNEL); |
|
err = -ENOMEM; |
|
if (!elem) |
|
goto out; |
|
} |
|
if (encode) { |
|
err = desc->xcode(desc, elem); |
|
if (err) |
|
goto out; |
|
memcpy(c, elem, avail_here); |
|
} else |
|
memcpy(elem, c, avail_here); |
|
copied = avail_here; |
|
} |
|
base = buf->head->iov_len; /* align to start of pages */ |
|
} |
|
|
|
/* process pages array */ |
|
base -= buf->head->iov_len; |
|
if (todo && base < buf->page_len) { |
|
unsigned int avail_page; |
|
|
|
avail_here = min(todo, buf->page_len - base); |
|
todo -= avail_here; |
|
|
|
base += buf->page_base; |
|
ppages = buf->pages + (base >> PAGE_SHIFT); |
|
base &= ~PAGE_MASK; |
|
avail_page = min_t(unsigned int, PAGE_SIZE - base, |
|
avail_here); |
|
c = kmap(*ppages) + base; |
|
|
|
while (avail_here) { |
|
avail_here -= avail_page; |
|
if (copied || avail_page < desc->elem_size) { |
|
unsigned int l = min(avail_page, |
|
desc->elem_size - copied); |
|
if (!elem) { |
|
elem = kmalloc(desc->elem_size, |
|
GFP_KERNEL); |
|
err = -ENOMEM; |
|
if (!elem) |
|
goto out; |
|
} |
|
if (encode) { |
|
if (!copied) { |
|
err = desc->xcode(desc, elem); |
|
if (err) |
|
goto out; |
|
} |
|
memcpy(c, elem + copied, l); |
|
copied += l; |
|
if (copied == desc->elem_size) |
|
copied = 0; |
|
} else { |
|
memcpy(elem + copied, c, l); |
|
copied += l; |
|
if (copied == desc->elem_size) { |
|
err = desc->xcode(desc, elem); |
|
if (err) |
|
goto out; |
|
copied = 0; |
|
} |
|
} |
|
avail_page -= l; |
|
c += l; |
|
} |
|
while (avail_page >= desc->elem_size) { |
|
err = desc->xcode(desc, c); |
|
if (err) |
|
goto out; |
|
c += desc->elem_size; |
|
avail_page -= desc->elem_size; |
|
} |
|
if (avail_page) { |
|
unsigned int l = min(avail_page, |
|
desc->elem_size - copied); |
|
if (!elem) { |
|
elem = kmalloc(desc->elem_size, |
|
GFP_KERNEL); |
|
err = -ENOMEM; |
|
if (!elem) |
|
goto out; |
|
} |
|
if (encode) { |
|
if (!copied) { |
|
err = desc->xcode(desc, elem); |
|
if (err) |
|
goto out; |
|
} |
|
memcpy(c, elem + copied, l); |
|
copied += l; |
|
if (copied == desc->elem_size) |
|
copied = 0; |
|
} else { |
|
memcpy(elem + copied, c, l); |
|
copied += l; |
|
if (copied == desc->elem_size) { |
|
err = desc->xcode(desc, elem); |
|
if (err) |
|
goto out; |
|
copied = 0; |
|
} |
|
} |
|
} |
|
if (avail_here) { |
|
kunmap(*ppages); |
|
ppages++; |
|
c = kmap(*ppages); |
|
} |
|
|
|
avail_page = min(avail_here, |
|
(unsigned int) PAGE_SIZE); |
|
} |
|
base = buf->page_len; /* align to start of tail */ |
|
} |
|
|
|
/* process tail */ |
|
base -= buf->page_len; |
|
if (todo) { |
|
c = buf->tail->iov_base + base; |
|
if (copied) { |
|
unsigned int l = desc->elem_size - copied; |
|
|
|
if (encode) |
|
memcpy(c, elem + copied, l); |
|
else { |
|
memcpy(elem + copied, c, l); |
|
err = desc->xcode(desc, elem); |
|
if (err) |
|
goto out; |
|
} |
|
todo -= l; |
|
c += l; |
|
} |
|
while (todo) { |
|
err = desc->xcode(desc, c); |
|
if (err) |
|
goto out; |
|
c += desc->elem_size; |
|
todo -= desc->elem_size; |
|
} |
|
} |
|
err = 0; |
|
|
|
out: |
|
kfree(elem); |
|
if (ppages) |
|
kunmap(*ppages); |
|
return err; |
|
} |
|
|
|
int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base, |
|
struct xdr_array2_desc *desc) |
|
{ |
|
if (base >= buf->len) |
|
return -EINVAL; |
|
|
|
return xdr_xcode_array2(buf, base, desc, 0); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_decode_array2); |
|
|
|
int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base, |
|
struct xdr_array2_desc *desc) |
|
{ |
|
if ((unsigned long) base + 4 + desc->array_len * desc->elem_size > |
|
buf->head->iov_len + buf->page_len + buf->tail->iov_len) |
|
return -EINVAL; |
|
|
|
return xdr_xcode_array2(buf, base, desc, 1); |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_encode_array2); |
|
|
|
int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, |
|
unsigned int len, |
|
int (*actor)(struct scatterlist *, void *), void *data) |
|
{ |
|
int i, ret = 0; |
|
unsigned int page_len, thislen, page_offset; |
|
struct scatterlist sg[1]; |
|
|
|
sg_init_table(sg, 1); |
|
|
|
if (offset >= buf->head[0].iov_len) { |
|
offset -= buf->head[0].iov_len; |
|
} else { |
|
thislen = buf->head[0].iov_len - offset; |
|
if (thislen > len) |
|
thislen = len; |
|
sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); |
|
ret = actor(sg, data); |
|
if (ret) |
|
goto out; |
|
offset = 0; |
|
len -= thislen; |
|
} |
|
if (len == 0) |
|
goto out; |
|
|
|
if (offset >= buf->page_len) { |
|
offset -= buf->page_len; |
|
} else { |
|
page_len = buf->page_len - offset; |
|
if (page_len > len) |
|
page_len = len; |
|
len -= page_len; |
|
page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1); |
|
i = (offset + buf->page_base) >> PAGE_SHIFT; |
|
thislen = PAGE_SIZE - page_offset; |
|
do { |
|
if (thislen > page_len) |
|
thislen = page_len; |
|
sg_set_page(sg, buf->pages[i], thislen, page_offset); |
|
ret = actor(sg, data); |
|
if (ret) |
|
goto out; |
|
page_len -= thislen; |
|
i++; |
|
page_offset = 0; |
|
thislen = PAGE_SIZE; |
|
} while (page_len != 0); |
|
offset = 0; |
|
} |
|
if (len == 0) |
|
goto out; |
|
if (offset < buf->tail[0].iov_len) { |
|
thislen = buf->tail[0].iov_len - offset; |
|
if (thislen > len) |
|
thislen = len; |
|
sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); |
|
ret = actor(sg, data); |
|
len -= thislen; |
|
} |
|
if (len != 0) |
|
ret = -EINVAL; |
|
out: |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_process_buf); |
|
|
|
/** |
|
* xdr_stream_decode_opaque - Decode variable length opaque |
|
* @xdr: pointer to xdr_stream |
|
* @ptr: location to store opaque data |
|
* @size: size of storage buffer @ptr |
|
* |
|
* Return values: |
|
* On success, returns size of object stored in *@ptr |
|
* %-EBADMSG on XDR buffer overflow |
|
* %-EMSGSIZE on overflow of storage buffer @ptr |
|
*/ |
|
ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size) |
|
{ |
|
ssize_t ret; |
|
void *p; |
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, size); |
|
if (ret <= 0) |
|
return ret; |
|
memcpy(ptr, p, ret); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque); |
|
|
|
/** |
|
* xdr_stream_decode_opaque_dup - Decode and duplicate variable length opaque |
|
* @xdr: pointer to xdr_stream |
|
* @ptr: location to store pointer to opaque data |
|
* @maxlen: maximum acceptable object size |
|
* @gfp_flags: GFP mask to use |
|
* |
|
* Return values: |
|
* On success, returns size of object stored in *@ptr |
|
* %-EBADMSG on XDR buffer overflow |
|
* %-EMSGSIZE if the size of the object would exceed @maxlen |
|
* %-ENOMEM on memory allocation failure |
|
*/ |
|
ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, |
|
size_t maxlen, gfp_t gfp_flags) |
|
{ |
|
ssize_t ret; |
|
void *p; |
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); |
|
if (ret > 0) { |
|
*ptr = kmemdup(p, ret, gfp_flags); |
|
if (*ptr != NULL) |
|
return ret; |
|
ret = -ENOMEM; |
|
} |
|
*ptr = NULL; |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup); |
|
|
|
/** |
|
* xdr_stream_decode_string - Decode variable length string |
|
* @xdr: pointer to xdr_stream |
|
* @str: location to store string |
|
* @size: size of storage buffer @str |
|
* |
|
* Return values: |
|
* On success, returns length of NUL-terminated string stored in *@str |
|
* %-EBADMSG on XDR buffer overflow |
|
* %-EMSGSIZE on overflow of storage buffer @str |
|
*/ |
|
ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size) |
|
{ |
|
ssize_t ret; |
|
void *p; |
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, size); |
|
if (ret > 0) { |
|
memcpy(str, p, ret); |
|
str[ret] = '\0'; |
|
return strlen(str); |
|
} |
|
*str = '\0'; |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_string); |
|
|
|
/** |
|
* xdr_stream_decode_string_dup - Decode and duplicate variable length string |
|
* @xdr: pointer to xdr_stream |
|
* @str: location to store pointer to string |
|
* @maxlen: maximum acceptable string length |
|
* @gfp_flags: GFP mask to use |
|
* |
|
* Return values: |
|
* On success, returns length of NUL-terminated string stored in *@ptr |
|
* %-EBADMSG on XDR buffer overflow |
|
* %-EMSGSIZE if the size of the string would exceed @maxlen |
|
* %-ENOMEM on memory allocation failure |
|
*/ |
|
ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, |
|
size_t maxlen, gfp_t gfp_flags) |
|
{ |
|
void *p; |
|
ssize_t ret; |
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); |
|
if (ret > 0) { |
|
char *s = kmemdup_nul(p, ret, gfp_flags); |
|
if (s != NULL) { |
|
*str = s; |
|
return strlen(s); |
|
} |
|
ret = -ENOMEM; |
|
} |
|
*str = NULL; |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup);
|
|
|