From 5a80a54d21c96590d013378d8c5f65f879451ab4 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Fri, 16 Nov 2012 10:01:30 -0500 Subject: [PATCH] nfsd4: reorganize write decoding In preparation for moving some of it elsewhere. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4xdr.c | 62 +++++++++++++++++++++++++++++++---------------- 1 file changed, 41 insertions(+), 21 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index cfebc9c4f4c9..579dc707bad9 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1139,12 +1139,30 @@ nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify DECODE_TAIL; } +static int fill_in_write_vector(struct kvec *vec, struct kvec *head, struct page **pagelist, int buflen) +{ + int i = 1; + + vec[0].iov_base = head->iov_base; + vec[0].iov_len = min_t(int, buflen, head->iov_len); + buflen -= vec[0].iov_len; + + while (buflen) { + vec[i].iov_base = page_address(pagelist[i - 1]); + vec[i].iov_len = min_t(int, PAGE_SIZE, buflen); + buflen -= vec[i].iov_len; + i++; + } + return i; +} + static __be32 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write) { int avail; - int v; int len; + struct page **pagelist; + struct kvec head; DECODE_HEAD; status = nfsd4_decode_stateid(argp, &write->wr_stateid); @@ -1167,27 +1185,29 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write) __FILE__, __LINE__); goto xdr_error; } - argp->rqstp->rq_vec[0].iov_base = p; - argp->rqstp->rq_vec[0].iov_len = avail; - v = 0; - len = write->wr_buflen; - while (len > argp->rqstp->rq_vec[v].iov_len) { - len -= argp->rqstp->rq_vec[v].iov_len; - v++; - argp->rqstp->rq_vec[v].iov_base = page_address(argp->pagelist[0]); - argp->pagelist++; - if (argp->pagelen >= PAGE_SIZE) { - argp->rqstp->rq_vec[v].iov_len = PAGE_SIZE; - argp->pagelen -= PAGE_SIZE; - } else { - argp->rqstp->rq_vec[v].iov_len = argp->pagelen; - argp->pagelen -= len; - } + head.iov_base = p; + head.iov_len = avail; + WARN_ON(avail != (XDR_QUADLEN(avail) << 2)); + pagelist = argp->pagelist; + + len = XDR_QUADLEN(write->wr_buflen) << 2; + if (len >= avail) { + int pages; + + len -= avail; + + pages = len >> PAGE_SHIFT; + argp->pagelist += pages; + argp->pagelen -= pages * PAGE_SIZE; + len -= pages * PAGE_SIZE; + + argp->p = (__be32 *)page_address(argp->pagelist[0]); + argp->end = argp->p + XDR_QUADLEN(PAGE_SIZE); } - argp->end = (__be32*) (argp->rqstp->rq_vec[v].iov_base + argp->rqstp->rq_vec[v].iov_len); - argp->p = (__be32*) (argp->rqstp->rq_vec[v].iov_base + (XDR_QUADLEN(len) << 2)); - argp->rqstp->rq_vec[v].iov_len = len; - write->wr_vlen = v+1; + argp->p += XDR_QUADLEN(len); + write->wr_vlen = fill_in_write_vector(argp->rqstp->rq_vec, + &head, pagelist, write->wr_buflen); + WARN_ON_ONCE(write->wr_vlen > ARRAY_SIZE(argp->rqstp->rq_vec)); DECODE_TAIL; }