nfsd4: reorganize write decoding (5a80a54d) · Commits · 戴 / test

fs/nfsd/nfs4xdr.c

+41 −21

Original line number	Diff line number	Diff line
		@@ -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;
		}

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