[PATCH v10 06/19] nfsd: manage netns reference in nfsd_open_local_fh

Mike Snitzer
2024-06-30T16:37:51Z

Use maybe_get_net() and put_net() in nfsd_open_local_fh().
Also refactor nfsd_open_local_fh() slightly.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
fs/nfsd/localio.c | 40 +++++++++++++++++++++++-----------------
1 file changed, 23 insertions(+), 17 deletions(-)

diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c
index 2eedeaeab533..0f81c340acc5 100644
--- a/fs/nfsd/localio.c
+++ b/fs/nfsd/localio.c
@@ -99,16 +99,11 @@ nfsd_local_fakerqst_destroy(struct svc_rqst *rqstp)

static struct svc_rqst *
nfsd_local_fakerqst_create(struct net *net, struct rpc_clnt *rpc_clnt,
- const struct cred *cred)
+ const struct cred *cred, struct svc_serv *serv)
{
- struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct svc_rqst *rqstp;
int status;

- /* FIXME: not running in nfsd context, must get reference on nfsd_serv */
- if (unlikely(!READ_ONCE(nn->nfsd_serv)))
- return ERR_PTR(-ENXIO);
-
rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL);
if (!rqstp)
return ERR_PTR(-ENOMEM);
@@ -118,10 +113,10 @@ nfsd_local_fakerqst_create(struct net *net, struct rpc_clnt *rpc_clnt,
status = -ENOMEM;
goto out_err;
}
-
rqstp->rq_xprt->xpt_net = net;
+
__set_bit(RQ_SECURE, &rqstp->rq_flags);
- rqstp->rq_server = nn->nfsd_serv;
+ rqstp->rq_server = serv;
/*
* These constants aren't actively used in this fake svc_rqst,
* which bypasses SUNRPC, but they must pass negative checks.
@@ -195,26 +190,39 @@ int nfsd_open_local_fh(struct net *cl_nfssvc_net,
{
int mayflags = NFSD_MAY_LOCALIO;
int status = 0;
+ struct nfsd_net *nn;
const struct cred *save_cred;
struct svc_rqst *rqstp;
struct svc_fh fh;
struct nfsd_file *nf;
+ struct svc_serv *serv;
__be32 beres;

+ if (nfs_fh->size > NFS4_FHSIZE)
+ return -EINVAL;
+
+ /* Not running in nfsd context, must safely get reference on nfsd_serv */
+ cl_nfssvc_net = maybe_get_net(cl_nfssvc_net);
+ if (!cl_nfssvc_net)
+ return -ENXIO;
+ nn = net_generic(cl_nfssvc_net, nfsd_net_id);
+
+ serv = READ_ONCE(nn->nfsd_serv);
+ if (unlikely(!serv)) {
+ status = -ENXIO;
+ goto out_net;
+ }
+
/* Save creds before calling into nfsd */
save_cred = get_current_cred();

- rqstp = nfsd_local_fakerqst_create(cl_nfssvc_net, rpc_clnt, cred);
+ rqstp = nfsd_local_fakerqst_create(cl_nfssvc_net, rpc_clnt, cred, serv);
if (IS_ERR(rqstp)) {
status = PTR_ERR(rqstp);
goto out_revertcred;
}

/* nfs_fh -> svc_fh */
- if (nfs_fh->size > NFS4_FHSIZE) {
- status = -EINVAL;
- goto out;
- }
fh_init(&fh, NFS4_FHSIZE);
fh.fh_handle.fh_size = nfs_fh->size;
memcpy(fh.fh_handle.fh_raw, nfs_fh->data, nfs_fh->size);
@@ -229,17 +237,15 @@ int nfsd_open_local_fh(struct net *cl_nfssvc_net,
status = nfs_stat_to_errno(be32_to_cpu(beres));
goto out_fh_put;
}
-
*pfilp = get_file(nf->nf_file);
-
nfsd_file_put(nf);
out_fh_put:
fh_put(&fh);
-
-out:
nfsd_local_fakerqst_destroy(rqstp);
out_revertcred:
revert_creds(save_cred);
+out_net:
+ put_net(cl_nfssvc_net);
return status;
}
EXPORT_SYMBOL_GPL(nfsd_open_local_fh);
--
2.44.0