Commit d4318acd authored by Jeff Layton's avatar Jeff Layton Committed by J. Bruce Fields
Browse files

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: default avatarJeff Layton <jlayton@primarydata.com>
parent 7f5ef2e9

fs/nfsd/nfs4recover.c

+83 −13
Original line number Diff line number Diff line
@@ -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);

}

fs/nfsd/nfs4state.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

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