From 9b3234b9220aae5387b60bc35a424ab6748b2b59 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 4 Dec 2012 18:03:46 -0500 Subject: nfsd4: disable zero-copy on non-final read ops To ensure ordering of read data with any following operations, turn off zero copy if the read is not the final operation in the compound. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4proc.c | 11 +++++++++++ fs/nfsd/nfs4state.c | 8 -------- fs/nfsd/xdr4.h | 8 ++++++++ 3 files changed, 19 insertions(+), 8 deletions(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index bd67f4d6dfc6..2a2d9b06a413 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -692,6 +692,17 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, if (read->rd_offset >= OFFSET_MAX) return nfserr_inval; + /* + * If we do a zero copy read, then a client will see read data + * that reflects the state of the file *after* performing the + * following compound. + * + * To ensure proper ordering, we therefore turn off zero copy if + * the client wants us to do more in this compound: + */ + if (!nfsd4_last_compound_op(rqstp)) + rqstp->rq_splice_ok = false; + nfs4_lock_state(); /* check stateid */ if ((status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 8e2555112966..8e127b39d323 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1855,14 +1855,6 @@ out_free_session: goto out; } -static bool nfsd4_last_compound_op(struct svc_rqst *rqstp) -{ - struct nfsd4_compoundres *resp = rqstp->rq_resp; - struct nfsd4_compoundargs *argp = rqstp->rq_argp; - - return argp->opcnt == resp->opcnt; -} - static __be32 nfsd4_map_bcts_dir(u32 *dir) { switch (*dir) { diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h index 331f8a3277ab..0889bfb43dc9 100644 --- a/fs/nfsd/xdr4.h +++ b/fs/nfsd/xdr4.h @@ -528,6 +528,14 @@ static inline bool nfsd4_not_cached(struct nfsd4_compoundres *resp) || nfsd4_is_solo_sequence(resp); } +static inline bool nfsd4_last_compound_op(struct svc_rqst *rqstp) +{ + struct nfsd4_compoundres *resp = rqstp->rq_resp; + struct nfsd4_compoundargs *argp = rqstp->rq_argp; + + return argp->opcnt == resp->opcnt; +} + #define NFS4_SVC_XDRSIZE sizeof(struct nfsd4_compoundargs) static inline void -- cgit v1.2.3