nfsd: Ensure sampling of the commit verifier is atomic with the commit

When we have a successful commit, ensure we sample the commit verifier
before releasing the lock.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Trond Myklebust 2020-01-06 13:40:36 -05:00 committed by J. Bruce Fields
parent 809fe3c533
commit 524ff1af22
6 changed files with 14 additions and 12 deletions

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@ -683,7 +683,8 @@ nfsd3_proc_commit(struct svc_rqst *rqstp)
RETURN_STATUS(nfserr_inval);
fh_copy(&resp->fh, &argp->fh);
nfserr = nfsd_commit(rqstp, &resp->fh, argp->offset, argp->count);
nfserr = nfsd_commit(rqstp, &resp->fh, argp->offset, argp->count,
resp->verf);
RETURN_STATUS(nfserr);
}

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@ -1121,16 +1121,12 @@ int
nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p)
{
struct nfsd3_commitres *resp = rqstp->rq_resp;
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
__be32 verf[2];
p = encode_wcc_data(rqstp, p, &resp->fh);
/* Write verifier */
if (resp->status == 0) {
/* unique identifier, y2038 overflow can be ignored */
nfsd_copy_boot_verifier(verf, nn);
*p++ = verf[0];
*p++ = verf[1];
*p++ = resp->verf[0];
*p++ = resp->verf[1];
}
return xdr_ressize_check(rqstp, p);
}

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@ -590,9 +590,9 @@ nfsd4_commit(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
{
struct nfsd4_commit *commit = &u->commit;
gen_boot_verifier(&commit->co_verf, SVC_NET(rqstp));
return nfsd_commit(rqstp, &cstate->current_fh, commit->co_offset,
commit->co_count);
commit->co_count,
(__be32 *)commit->co_verf.data);
}
static __be32

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@ -1105,7 +1105,7 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
*/
__be32
nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
loff_t offset, unsigned long count)
loff_t offset, unsigned long count, __be32 *verf)
{
struct nfsd_file *nf;
loff_t end = LLONG_MAX;
@ -1130,6 +1130,8 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);
switch (err2) {
case 0:
nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
nfsd_net_id));
break;
case -EINVAL:
err = nfserr_notsupp;
@ -1140,7 +1142,9 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
nfsd_net_id));
}
up_write(&nf->nf_rwsem);
}
} else
nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
nfsd_net_id));
nfsd_file_put(nf);
out:

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@ -74,7 +74,7 @@ __be32 do_nfsd_create(struct svc_rqst *, struct svc_fh *,
struct svc_fh *res, int createmode,
u32 *verifier, bool *truncp, bool *created);
__be32 nfsd_commit(struct svc_rqst *, struct svc_fh *,
loff_t, unsigned long);
loff_t, unsigned long, __be32 *verf);
#endif /* CONFIG_NFSD_V3 */
int nfsd_open_break_lease(struct inode *, int);
__be32 nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t,

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@ -223,6 +223,7 @@ struct nfsd3_pathconfres {
struct nfsd3_commitres {
__be32 status;
struct svc_fh fh;
__be32 verf[2];
};
struct nfsd3_getaclres {