diff options
Diffstat (limited to 'net/sunrpc/svc.c')
-rw-r--r-- | net/sunrpc/svc.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index f19987f5d3b5..a155e2de19aa 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -1533,3 +1533,45 @@ u32 svc_max_payload(const struct svc_rqst *rqstp) return max; } EXPORT_SYMBOL_GPL(svc_max_payload); + +/** + * svc_fill_write_vector - Construct data argument for VFS write call + * @rqstp: svc_rqst to operate on + * @first: buffer containing first section of write payload + * @total: total number of bytes of write payload + * + * Returns the number of elements populated in the data argument array. + */ +unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct kvec *first, + size_t total) +{ + struct kvec *vec = rqstp->rq_vec; + struct page **pages; + unsigned int i; + + /* Some types of transport can present the write payload + * entirely in rq_arg.pages. In this case, @first is empty. + */ + i = 0; + if (first->iov_len) { + vec[i].iov_base = first->iov_base; + vec[i].iov_len = min_t(size_t, total, first->iov_len); + total -= vec[i].iov_len; + ++i; + } + + WARN_ON_ONCE(rqstp->rq_arg.page_base != 0); + pages = rqstp->rq_arg.pages; + while (total) { + vec[i].iov_base = page_address(*pages); + vec[i].iov_len = min_t(size_t, total, PAGE_SIZE); + total -= vec[i].iov_len; + ++i; + + ++pages; + } + + WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec)); + return i; +} +EXPORT_SYMBOL_GPL(svc_fill_write_vector); |