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authorJ. Bruce Fields <bfields@redhat.com>2012-12-04 18:03:46 -0500
committerJ. Bruce Fields <bfields@redhat.com>2012-12-17 16:02:41 -0500
commit9b3234b9220aae5387b60bc35a424ab6748b2b59 (patch)
treeeeaf7761a957cd3acdd6c55a91587b28998d0bd9 /fs/nfsd
parent3a28e331115be5130fe061e6b4183b29385116a6 (diff)
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 <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
-rw-r--r--fs/nfsd/nfs4proc.c11
-rw-r--r--fs/nfsd/nfs4state.c8
-rw-r--r--fs/nfsd/xdr4.h8
3 files changed, 19 insertions, 8 deletions
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index bd67f4d6dfc..2a2d9b06a41 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 8e255511296..8e127b39d32 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 331f8a3277a..0889bfb43dc 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