From bb6e8a9f4005237401a45f1ea43db060ea5f9725 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 10 Apr 2006 22:55:33 -0700 Subject: [PATCH] [PATCH] knfsd: nfsd4: fix corruption on readdir encoding with 64k pages Fix corruption on readdir encoding with 64k pages. Signed-off-by: J. Bruce Fields Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfsd/nfs4xdr.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index f2710cfc0bc5..de3998f15f10 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2157,7 +2157,7 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_re { int maxcount; loff_t offset; - u32 *page, *savep; + u32 *page, *savep, *tailbase; ENCODE_HEAD; if (nfserr) @@ -2173,6 +2173,7 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_re WRITE32(0); ADJUST_ARGS(); resp->xbuf->head[0].iov_len = ((char*)resp->p) - (char*)resp->xbuf->head[0].iov_base; + tailbase = p; maxcount = PAGE_SIZE; if (maxcount > readdir->rd_maxcount) @@ -2217,14 +2218,12 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_re *p++ = htonl(readdir->common.err == nfserr_eof); resp->xbuf->page_len = ((char*)p) - (char*)page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]); - /* allocate a page for the tail */ - svc_take_page(resp->rqstp); - resp->xbuf->tail[0].iov_base = - page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]); - resp->rqstp->rq_restailpage = resp->rqstp->rq_resused-1; + /* Use rest of head for padding and remaining ops: */ + resp->rqstp->rq_restailpage = 0; + resp->xbuf->tail[0].iov_base = tailbase; resp->xbuf->tail[0].iov_len = 0; resp->p = resp->xbuf->tail[0].iov_base; - resp->end = resp->p + PAGE_SIZE/4; + resp->end = resp->p + (PAGE_SIZE - resp->xbuf->head[0].iov_len)/4; return 0; err_no_verf: -- 2.20.1