Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

nfsd4: disable zero-copy on non-final read ops

Browse source 
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>
This commit is contained in:
J. Bruce Fields 2012-12-04 18:03:46 -05:00
parent 3a28e33111
commit 9b3234b922
3 changed files with 19 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
fs/nfsd/nfs4proc.c
View file

@ -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),

8
fs/nfsd/nfs4state.c
View file

@ -1855,14 +1855,6 @@ nfsd4_create_session(struct svc_rqst *rqstp,
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) {

8
fs/nfsd/xdr4.h
View file

@ -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