From 294ac32e99861f6efee548a6b7afb27c32cd502f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 30 Jul 2014 08:27:15 -0400 Subject: [PATCH] nfsd: protect clid and verifier generation with client_lock The clid counter is a global counter currently. Move it to be a per-net property so that it can be properly protected by the nn->client_lock instead of relying on the client_mutex. The verifier generator is also potentially racy if there are two simultaneous callers. Generate the verifier when we generate the clid value, so it's also created under the client_lock. With this, there's no need to keep two counters as they'd always be in sync anyway, so just use the clientid_counter for both. As Trond points out, what would be best is to eventually move this code to use IDR instead of the hash tables. That would also help ensure uniqueness, but that's probably best done as a separate project. Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/netns.h | 6 +++--- fs/nfsd/nfs4state.c | 21 +++++++++------------ 2 files changed, 12 insertions(+), 15 deletions(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index e1f479c162b5..3831ef6e5c75 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -92,9 +92,7 @@ struct nfsd_net { bool nfsd_net_up; bool lockd_up; - /* - * Time of server startup - */ + /* Time of server startup */ struct timeval nfssvc_boot; /* @@ -103,6 +101,8 @@ struct nfsd_net { */ unsigned int max_connections; + u32 clientid_counter; + struct svc_serv *nfsd_serv; }; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 037bb924ce63..2cb559017ac9 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1812,28 +1812,26 @@ static bool mach_creds_match(struct nfs4_client *cl, struct svc_rqst *rqstp) return 0 == strcmp(cl->cl_cred.cr_principal, cr->cr_principal); } -static void gen_clid(struct nfs4_client *clp, struct nfsd_net *nn) -{ - static u32 current_clientid = 1; - - clp->cl_clientid.cl_boot = nn->boot_time; - clp->cl_clientid.cl_id = current_clientid++; -} - -static void gen_confirm(struct nfs4_client *clp) +static void gen_confirm(struct nfs4_client *clp, struct nfsd_net *nn) { __be32 verf[2]; - static u32 i; /* * This is opaque to client, so no need to byte-swap. Use * __force to keep sparse happy */ verf[0] = (__force __be32)get_seconds(); - verf[1] = (__force __be32)i++; + verf[1] = (__force __be32)nn->clientid_counter; memcpy(clp->cl_confirm.data, verf, sizeof(clp->cl_confirm.data)); } +static void gen_clid(struct nfs4_client *clp, struct nfsd_net *nn) +{ + clp->cl_clientid.cl_boot = nn->boot_time; + clp->cl_clientid.cl_id = nn->clientid_counter++; + gen_confirm(clp, nn); +} + static struct nfs4_stid * find_stateid_locked(struct nfs4_client *cl, stateid_t *t) { @@ -1884,7 +1882,6 @@ static struct nfs4_client *create_client(struct xdr_netobj name, clear_bit(0, &clp->cl_cb_slot_busy); copy_verf(clp, verf); rpc_copy_addr((struct sockaddr *) &clp->cl_addr, sa); - gen_confirm(clp); clp->cl_cb_session = NULL; clp->net = net; return clp;