From d4318acd5d2d34d69a46537f057b20a8f0266e1e Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 12 Sep 2014 16:40:21 -0400 Subject: [PATCH] nfsd: pass extra info in env vars to upcalls to allow for early grace period end In order to support lifting the grace period early, we must tell nfsdcltrack what sort of client the "create" upcall is for. We can't reliably tell if a v4.0 client has completed reclaiming, so we can only lift the grace period once all the v4.1+ clients have issued a RECLAIM_COMPLETE and if there are no v4.0 clients. Also, in order to lift the grace period, we have to tell userland when the grace period started so that it can tell whether a RECLAIM_COMPLETE has been issued for each client since then. Since this is all optional info, we pass it along in environment variables to the "init" and "create" upcalls. By doing this, we don't need to revise the upcall format. The UMH upcall can simply make use of this info if it happens to be present. If it's not then it can just avoid lifting the grace period early. Signed-off-by: Jeff Layton --- fs/nfsd/nfs4recover.c | 96 +++++++++++++++++++++++++++++++++++++------ fs/nfsd/nfs4state.c | 4 +- 2 files changed, 85 insertions(+), 15 deletions(-) diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 9affa22e7d35..b4289060ebaf 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -1067,6 +1067,8 @@ MODULE_PARM_DESC(cltrack_legacy_disable, #define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR=" #define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR=" +#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION=" +#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START=" static char * nfsd4_cltrack_legacy_topdir(void) @@ -1131,10 +1133,60 @@ nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name) return result; } +static char * +nfsd4_cltrack_client_has_session(struct nfs4_client *clp) +{ + int copied; + size_t len; + char *result; + + /* prefix + Y/N character + terminating NULL */ + len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1; + + result = kmalloc(len, GFP_KERNEL); + if (!result) + return result; + + copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c", + clp->cl_minorversion ? 'Y' : 'N'); + if (copied >= len) { + /* just return nothing if output was truncated */ + kfree(result); + return NULL; + } + + return result; +} + +static char * +nfsd4_cltrack_grace_start(time_t grace_start) +{ + int copied; + size_t len; + char *result; + + /* prefix + max width of int64_t string + terminating NULL */ + len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1; + + result = kmalloc(len, GFP_KERNEL); + if (!result) + return result; + + copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%ld", + grace_start); + if (copied >= len) { + /* just return nothing if output was truncated */ + kfree(result); + return NULL; + } + + return result; +} + static int -nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *legacy) +nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1) { - char *envp[2]; + char *envp[3]; char *argv[4]; int ret; @@ -1145,10 +1197,12 @@ nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *legacy) dprintk("%s: cmd: %s\n", __func__, cmd); dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)"); - dprintk("%s: legacy: %s\n", __func__, legacy ? legacy : "(null)"); + dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)"); + dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)"); - envp[0] = legacy; - envp[1] = NULL; + envp[0] = env0; + envp[1] = env1; + envp[2] = NULL; argv[0] = (char *)cltrack_prog; argv[1] = cmd; @@ -1192,28 +1246,40 @@ bin_to_hex_dup(const unsigned char *src, int srclen) } static int -nfsd4_umh_cltrack_init(struct net __attribute__((unused)) *net) +nfsd4_umh_cltrack_init(struct net *net) { + int ret; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time); + /* XXX: The usermode helper s not working in container yet. */ if (net != &init_net) { WARN(1, KERN_ERR "NFSD: attempt to initialize umh client " "tracking in a container!\n"); return -EINVAL; } - return nfsd4_umh_cltrack_upcall("init", NULL, NULL); + + ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL); + kfree(grace_start); + return ret; } static void nfsd4_umh_cltrack_create(struct nfs4_client *clp) { - char *hexid; + char *hexid, *has_session, *grace_start; + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len); if (!hexid) { dprintk("%s: can't allocate memory for upcall!\n", __func__); return; } - nfsd4_umh_cltrack_upcall("create", hexid, NULL); + has_session = nfsd4_cltrack_client_has_session(clp); + grace_start = nfsd4_cltrack_grace_start(nn->boot_time); + nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start); + kfree(has_session); + kfree(grace_start); kfree(hexid); } @@ -1227,7 +1293,7 @@ nfsd4_umh_cltrack_remove(struct nfs4_client *clp) dprintk("%s: can't allocate memory for upcall!\n", __func__); return; } - nfsd4_umh_cltrack_upcall("remove", hexid, NULL); + nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL); kfree(hexid); } @@ -1235,17 +1301,21 @@ static int nfsd4_umh_cltrack_check(struct nfs4_client *clp) { int ret; - char *hexid, *legacy; + char *hexid, *has_session, *legacy; hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len); if (!hexid) { dprintk("%s: can't allocate memory for upcall!\n", __func__); return -ENOMEM; } + + has_session = nfsd4_cltrack_client_has_session(clp); legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name); - ret = nfsd4_umh_cltrack_upcall("check", hexid, legacy); + ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy); + kfree(has_session); kfree(legacy); kfree(hexid); + return ret; } @@ -1257,7 +1327,7 @@ nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn) sprintf(timestr, "%ld", nn->boot_time); legacy = nfsd4_cltrack_legacy_topdir(); - nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy); + nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL); kfree(legacy); } diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 8f7ace5942be..fc88b57516b2 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6350,10 +6350,10 @@ nfs4_state_start_net(struct net *net) ret = nfs4_state_create_net(net); if (ret) return ret; - nfsd4_client_tracking_init(net); nn->boot_time = get_seconds(); - locks_start_grace(net, &nn->nfsd4_manager); nn->grace_ended = false; + locks_start_grace(net, &nn->nfsd4_manager); + nfsd4_client_tracking_init(net); printk(KERN_INFO "NFSD: starting %ld-second grace period (net %p)\n", nn->nfsd4_grace, net); queue_delayed_work(laundry_wq, &nn->laundromat_work, nn->nfsd4_grace * HZ); -- 2.34.1