nfs4recover.c

   1/*
   2*  Copyright (c) 2004 The Regents of the University of Michigan.
   3*  Copyright (c) 2012 Jeff Layton <jlayton@redhat.com>
   4*  All rights reserved.
   5*
   6*  Andy Adamson <andros@citi.umich.edu>
   7*
   8*  Redistribution and use in source and binary forms, with or without
   9*  modification, are permitted provided that the following conditions
  10*  are met:
  11*
  12*  1. Redistributions of source code must retain the above copyright
  13*     notice, this list of conditions and the following disclaimer.
  14*  2. Redistributions in binary form must reproduce the above copyright
  15*     notice, this list of conditions and the following disclaimer in the
  16*     documentation and/or other materials provided with the distribution.
  17*  3. Neither the name of the University nor the names of its
  18*     contributors may be used to endorse or promote products derived
  19*     from this software without specific prior written permission.
  20*
  21*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  22*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  23*  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  24*  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25*  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  28*  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  29*  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  30*  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  31*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32*
  33*/
  34
  35#include <crypto/md5.h>
  36#include <crypto/sha2.h>
  37#include <linux/file.h>
  38#include <linux/slab.h>
  39#include <linux/namei.h>
  40#include <linux/sched.h>
  41#include <linux/fs.h>
  42#include <linux/module.h>
  43#include <net/net_namespace.h>
  44#include <linux/sunrpc/rpc_pipe_fs.h>
  45#include <linux/sunrpc/clnt.h>
  46#include <linux/nfsd/cld.h>
  47
  48#include "nfsd.h"
  49#include "state.h"
  50#include "vfs.h"
  51#include "netns.h"
  52
  53#define NFSDDBG_FACILITY                NFSDDBG_PROC
  54
  55/* Declarations */
  56struct nfsd4_client_tracking_ops {
  57	int (*init)(struct net *);
  58	void (*exit)(struct net *);
  59	void (*create)(struct nfs4_client *);
  60	void (*remove)(struct nfs4_client *);
  61	int (*check)(struct nfs4_client *);
  62	void (*grace_done)(struct nfsd_net *);
  63	uint8_t version;
  64	size_t msglen;
  65};
  66
  67static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops;
  68static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2;
  69
  70#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
  71/* Globals */
  72static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
  73
  74static int
  75nfs4_save_creds(const struct cred **original_creds)
  76{
  77	struct cred *new;
  78
  79	new = prepare_creds();
  80	if (!new)
  81		return -ENOMEM;
  82
  83	new->fsuid = GLOBAL_ROOT_UID;
  84	new->fsgid = GLOBAL_ROOT_GID;
  85	*original_creds = override_creds(new);
  86	return 0;
  87}
  88
  89static void
  90nfs4_reset_creds(const struct cred *original)
  91{
  92	put_cred(revert_creds(original));
  93}
  94
  95static void
  96nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname)
  97{
  98	u8 digest[MD5_DIGEST_SIZE];
  99
 100	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
 101			clname->len, clname->data);
 102
 103	md5(clname->data, clname->len, digest);
 104
 105	static_assert(HEXDIR_LEN == 2 * MD5_DIGEST_SIZE + 1);
 106	sprintf(dname, "%*phN", MD5_DIGEST_SIZE, digest);
 107}
 108
 109static void
 110__nfsd4_create_reclaim_record_grace(struct nfs4_client *clp,
 111				    char *dname, struct nfsd_net *nn)
 112{
 113	struct xdr_netobj name = { .len = strlen(dname), .data = dname };
 114	struct xdr_netobj princhash = { .len = 0, .data = NULL };
 115	struct nfs4_client_reclaim *crp;
 116
 117	crp = nfs4_client_to_reclaim(name, princhash, nn);
 118	crp->cr_clp = clp;
 119}
 120
 121static void
 122nfsd4_create_clid_dir(struct nfs4_client *clp)
 123{
 124	const struct cred *original_cred;
 125	char dname[HEXDIR_LEN];
 126	struct dentry *dir, *dentry;
 127	int status;
 128	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 129
 130	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 131		return;
 132	if (!nn->rec_file)
 133		return;
 134
 135	nfs4_make_rec_clidname(dname, &clp->cl_name);
 136
 137	status = nfs4_save_creds(&original_cred);
 138	if (status < 0)
 139		return;
 140
 141	status = mnt_want_write_file(nn->rec_file);
 142	if (status)
 143		goto out_creds;
 144
 145	dir = nn->rec_file->f_path.dentry;
 146
 147	dentry = start_creating(&nop_mnt_idmap, dir, &QSTR(dname));
 148	if (IS_ERR(dentry)) {
 149		status = PTR_ERR(dentry);
 150		goto out;
 151	}
 152	if (d_really_is_positive(dentry))
 153		/*
 154		 * In the 4.1 case, where we're called from
 155		 * reclaim_complete(), records from the previous reboot
 156		 * may still be left, so this is OK.
 157		 *
 158		 * In the 4.0 case, we should never get here; but we may
 159		 * as well be forgiving and just succeed silently.
 160		 */
 161		goto out_end;
 162	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, 0700, NULL);
 163	if (IS_ERR(dentry))
 164		status = PTR_ERR(dentry);
 165out_end:
 166	end_creating(dentry);
 167out:
 168	if (status == 0) {
 169		if (nn->in_grace)
 170			__nfsd4_create_reclaim_record_grace(clp, dname, nn);
 171		vfs_fsync(nn->rec_file, 0);
 172	} else {
 173		printk(KERN_ERR "NFSD: failed to write recovery record"
 174				" (err %d); please check that %s exists"
 175				" and is writeable", status,
 176				user_recovery_dirname);
 177	}
 178	mnt_drop_write_file(nn->rec_file);
 179out_creds:
 180	nfs4_reset_creds(original_cred);
 181}
 182
 183typedef int (recdir_func)(struct dentry *, char *, struct nfsd_net *);
 184
 185struct name_list {
 186	char name[HEXDIR_LEN];
 187	struct list_head list;
 188};
 189
 190struct nfs4_dir_ctx {
 191	struct dir_context ctx;
 192	struct list_head names;
 193};
 194
 195static bool
 196nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
 197		loff_t offset, u64 ino, unsigned int d_type)
 198{
 199	struct nfs4_dir_ctx *ctx =
 200		container_of(__ctx, struct nfs4_dir_ctx, ctx);
 201	struct name_list *entry;
 202
 203	if (namlen != HEXDIR_LEN - 1)
 204		return true;
 205	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
 206	if (entry == NULL)
 207		return false;
 208	memcpy(entry->name, name, HEXDIR_LEN - 1);
 209	entry->name[HEXDIR_LEN - 1] = '\0';
 210	list_add(&entry->list, &ctx->names);
 211	return true;
 212}
 213
 214static int
 215nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
 216{
 217	const struct cred *original_cred;
 218	struct dentry *dir = nn->rec_file->f_path.dentry;
 219	struct nfs4_dir_ctx ctx = {
 220		.ctx.actor = nfsd4_build_namelist,
 221		.names = LIST_HEAD_INIT(ctx.names)
 222	};
 223	struct name_list *entry, *tmp;
 224	int status;
 225
 226	status = nfs4_save_creds(&original_cred);
 227	if (status < 0)
 228		return status;
 229
 230	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
 231	if (status < 0) {
 232		nfs4_reset_creds(original_cred);
 233		return status;
 234	}
 235
 236	status = iterate_dir(nn->rec_file, &ctx.ctx);
 237
 238	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 239		if (!status)
 240			status = f(dir, entry->name, nn);
 241
 242		list_del(&entry->list);
 243		kfree(entry);
 244	}
 245	nfs4_reset_creds(original_cred);
 246
 247	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 248		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
 249		list_del(&entry->list);
 250		kfree(entry);
 251	}
 252	return status;
 253}
 254
 255static int
 256nfsd4_unlink_clid_dir(char *name, struct nfsd_net *nn)
 257{
 258	struct dentry *dir, *dentry;
 259	int status;
 260
 261	dprintk("NFSD: nfsd4_unlink_clid_dir. name %s\n", name);
 262
 263	dir = nn->rec_file->f_path.dentry;
 264	dentry = start_removing(&nop_mnt_idmap, dir, &QSTR(name));
 265	if (IS_ERR(dentry))
 266		return PTR_ERR(dentry);
 267
 268	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry, NULL);
 269	end_removing(dentry);
 270	return status;
 271}
 272
 273static void
 274__nfsd4_remove_reclaim_record_grace(const char *dname, int len,
 275		struct nfsd_net *nn)
 276{
 277	struct xdr_netobj name;
 278	struct nfs4_client_reclaim *crp;
 279
 280	name.data = kmemdup(dname, len, GFP_KERNEL);
 281	if (!name.data) {
 282		dprintk("%s: failed to allocate memory for name.data!\n",
 283			__func__);
 284		return;
 285	}
 286	name.len = len;
 287	crp = nfsd4_find_reclaim_client(name, nn);
 288	kfree(name.data);
 289	if (crp)
 290		nfs4_remove_reclaim_record(crp, nn);
 291}
 292
 293static void
 294nfsd4_remove_clid_dir(struct nfs4_client *clp)
 295{
 296	const struct cred *original_cred;
 297	char dname[HEXDIR_LEN];
 298	int status;
 299	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 300
 301	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 302		return;
 303
 304	nfs4_make_rec_clidname(dname, &clp->cl_name);
 305
 306	status = mnt_want_write_file(nn->rec_file);
 307	if (status)
 308		goto out;
 309	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 310
 311	status = nfs4_save_creds(&original_cred);
 312	if (status < 0)
 313		goto out_drop_write;
 314
 315	status = nfsd4_unlink_clid_dir(dname, nn);
 316	nfs4_reset_creds(original_cred);
 317	if (status == 0) {
 318		vfs_fsync(nn->rec_file, 0);
 319		if (nn->in_grace)
 320			__nfsd4_remove_reclaim_record_grace(dname,
 321					HEXDIR_LEN, nn);
 322	}
 323out_drop_write:
 324	mnt_drop_write_file(nn->rec_file);
 325out:
 326	if (status)
 327		printk("NFSD: Failed to remove expired client state directory"
 328				" %.*s\n", HEXDIR_LEN, dname);
 329}
 330
 331static int
 332purge_old(struct dentry *parent, char *cname, struct nfsd_net *nn)
 333{
 334	int status;
 335	struct dentry *child;
 336	struct xdr_netobj name;
 337
 338	if (strlen(cname) != HEXDIR_LEN - 1) {
 339		printk("%s: illegal name %s in recovery directory\n",
 340				__func__, cname);
 341		/* Keep trying; maybe the others are OK: */
 342		return 0;
 343	}
 344	name.data = kstrdup(cname, GFP_KERNEL);
 345	if (!name.data) {
 346		dprintk("%s: failed to allocate memory for name.data!\n",
 347			__func__);
 348		goto out;
 349	}
 350	name.len = HEXDIR_LEN;
 351	if (nfs4_has_reclaimed_state(name, nn))
 352		goto out_free;
 353
 354	inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
 355	child = lookup_one(&nop_mnt_idmap, &QSTR(cname), parent);
 356	if (!IS_ERR(child)) {
 357		status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child, NULL);
 358		if (status)
 359			printk("failed to remove client recovery directory %pd\n",
 360			       child);
 361		dput(child);
 362	}
 363	inode_unlock(d_inode(parent));
 364
 365out_free:
 366	kfree(name.data);
 367out:
 368	/* Keep trying, success or failure: */
 369	return 0;
 370}
 371
 372static void
 373nfsd4_recdir_purge_old(struct nfsd_net *nn)
 374{
 375	int status;
 376
 377	nn->in_grace = false;
 378	if (!nn->rec_file)
 379		return;
 380	status = mnt_want_write_file(nn->rec_file);
 381	if (status)
 382		goto out;
 383	status = nfsd4_list_rec_dir(purge_old, nn);
 384	if (status == 0)
 385		vfs_fsync(nn->rec_file, 0);
 386	mnt_drop_write_file(nn->rec_file);
 387out:
 388	nfs4_release_reclaim(nn);
 389	if (status)
 390		printk("nfsd4: failed to purge old clients from recovery"
 391			" directory %pD\n", nn->rec_file);
 392}
 393
 394static int
 395load_recdir(struct dentry *parent, char *cname, struct nfsd_net *nn)
 396{
 397	struct xdr_netobj name = { .len = HEXDIR_LEN, .data = cname };
 398	struct xdr_netobj princhash = { .len = 0, .data = NULL };
 399
 400	if (strlen(cname) != HEXDIR_LEN - 1) {
 401		printk("%s: illegal name %s in recovery directory\n",
 402				__func__, cname);
 403		/* Keep trying; maybe the others are OK: */
 404		return 0;
 405	}
 406	nfs4_client_to_reclaim(name, princhash, nn);
 407	return 0;
 408}
 409
 410static int
 411nfsd4_recdir_load(struct net *net) {
 412	int status;
 413	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
 414
 415	if (!nn->rec_file)
 416		return 0;
 417
 418	status = nfsd4_list_rec_dir(load_recdir, nn);
 419	if (status)
 420		printk("nfsd4: failed loading clients from recovery"
 421			" directory %pD\n", nn->rec_file);
 422	return status;
 423}
 424
 425/*
 426 * Hold reference to the recovery directory.
 427 */
 428
 429static int
 430nfsd4_init_recdir(struct net *net)
 431{
 432	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 433	const struct cred *original_cred;
 434	int status;
 435
 436	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
 437			user_recovery_dirname);
 438
 439	BUG_ON(nn->rec_file);
 440
 441	status = nfs4_save_creds(&original_cred);
 442	if (status < 0) {
 443		printk("NFSD: Unable to change credentials to find recovery"
 444		       " directory: error %d\n",
 445		       status);
 446		return status;
 447	}
 448
 449	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
 450	if (IS_ERR(nn->rec_file)) {
 451		printk("NFSD: unable to find recovery directory %s\n",
 452				user_recovery_dirname);
 453		status = PTR_ERR(nn->rec_file);
 454		nn->rec_file = NULL;
 455	}
 456
 457	nfs4_reset_creds(original_cred);
 458	if (!status)
 459		nn->in_grace = true;
 460	return status;
 461}
 462
 463static void
 464nfsd4_shutdown_recdir(struct net *net)
 465{
 466	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 467
 468	if (!nn->rec_file)
 469		return;
 470	fput(nn->rec_file);
 471	nn->rec_file = NULL;
 472}
 473
 474static int
 475nfs4_legacy_state_init(struct net *net)
 476{
 477	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 478	int i;
 479
 480	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
 481						sizeof(struct list_head),
 482						GFP_KERNEL);
 483	if (!nn->reclaim_str_hashtbl)
 484		return -ENOMEM;
 485
 486	for (i = 0; i < CLIENT_HASH_SIZE; i++)
 487		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
 488	nn->reclaim_str_hashtbl_size = 0;
 489
 490	return 0;
 491}
 492
 493static void
 494nfs4_legacy_state_shutdown(struct net *net)
 495{
 496	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 497
 498	kfree(nn->reclaim_str_hashtbl);
 499}
 500
 501static int
 502nfsd4_load_reboot_recovery_data(struct net *net)
 503{
 504	int status;
 505
 506	status = nfsd4_init_recdir(net);
 507	if (status)
 508		return status;
 509
 510	status = nfsd4_recdir_load(net);
 511	if (status)
 512		nfsd4_shutdown_recdir(net);
 513
 514	return status;
 515}
 516
 517static int
 518nfsd4_legacy_tracking_init(struct net *net)
 519{
 520	int status;
 521
 522	/* XXX: The legacy code won't work in a container */
 523	if (net != &init_net) {
 524		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
 525		return -EINVAL;
 526	}
 527
 528	status = nfs4_legacy_state_init(net);
 529	if (status)
 530		return status;
 531
 532	status = nfsd4_load_reboot_recovery_data(net);
 533	if (status)
 534		goto err;
 535	pr_info("NFSD: Using legacy client tracking operations.\n");
 536	return 0;
 537
 538err:
 539	nfs4_legacy_state_shutdown(net);
 540	return status;
 541}
 542
 543static void
 544nfsd4_legacy_tracking_exit(struct net *net)
 545{
 546	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 547
 548	nfs4_release_reclaim(nn);
 549	nfsd4_shutdown_recdir(net);
 550	nfs4_legacy_state_shutdown(net);
 551}
 552
 553/*
 554 * Change the NFSv4 recovery directory to recdir.
 555 */
 556int
 557nfs4_reset_recoverydir(char *recdir)
 558{
 559	int status;
 560	struct path path;
 561
 562	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
 563	if (status)
 564		return status;
 565	status = -ENOTDIR;
 566	if (d_is_dir(path.dentry)) {
 567		strscpy(user_recovery_dirname, recdir,
 568			sizeof(user_recovery_dirname));
 569		status = 0;
 570	}
 571	path_put(&path);
 572	return status;
 573}
 574
 575char *
 576nfs4_recoverydir(void)
 577{
 578	return user_recovery_dirname;
 579}
 580
 581static int
 582nfsd4_check_legacy_client(struct nfs4_client *clp)
 583{
 584	char dname[HEXDIR_LEN];
 585	struct nfs4_client_reclaim *crp;
 586	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 587	struct xdr_netobj name;
 588
 589	/* did we already find that this client is stable? */
 590	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 591		return 0;
 592
 593	nfs4_make_rec_clidname(dname, &clp->cl_name);
 594
 595	/* look for it in the reclaim hashtable otherwise */
 596	name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
 597	if (!name.data) {
 598		dprintk("%s: failed to allocate memory for name.data!\n",
 599			__func__);
 600		goto out_enoent;
 601	}
 602	name.len = HEXDIR_LEN;
 603	crp = nfsd4_find_reclaim_client(name, nn);
 604	kfree(name.data);
 605	if (crp) {
 606		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 607		crp->cr_clp = clp;
 608		return 0;
 609	}
 610
 611out_enoent:
 612	return -ENOENT;
 613}
 614
 615static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
 616	.init		= nfsd4_legacy_tracking_init,
 617	.exit		= nfsd4_legacy_tracking_exit,
 618	.create		= nfsd4_create_clid_dir,
 619	.remove		= nfsd4_remove_clid_dir,
 620	.check		= nfsd4_check_legacy_client,
 621	.grace_done	= nfsd4_recdir_purge_old,
 622	.version	= 1,
 623	.msglen		= 0,
 624};
 625#endif /* CONFIG_NFSD_LEGACY_CLIENT_TRACKING */
 626
 627/* Globals */
 628#define NFSD_PIPE_DIR		"nfsd"
 629#define NFSD_CLD_PIPE		"cld"
 630
 631/* per-net-ns structure for holding cld upcall info */
 632struct cld_net {
 633	struct rpc_pipe		*cn_pipe;
 634	spinlock_t		 cn_lock;
 635	struct list_head	 cn_list;
 636	unsigned int		 cn_xid;
 637#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
 638	bool			 cn_has_legacy;
 639#endif
 640};
 641
 642struct cld_upcall {
 643	struct list_head	 cu_list;
 644	struct cld_net		*cu_net;
 645	struct completion	 cu_done;
 646	union {
 647		struct cld_msg_hdr	 cu_hdr;
 648		struct cld_msg		 cu_msg;
 649		struct cld_msg_v2	 cu_msg_v2;
 650	} cu_u;
 651};
 652
 653static int
 654__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
 655{
 656	int ret;
 657	struct rpc_pipe_msg msg;
 658	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
 659
 660	memset(&msg, 0, sizeof(msg));
 661	msg.data = cmsg;
 662	msg.len = nn->client_tracking_ops->msglen;
 663
 664	ret = rpc_queue_upcall(pipe, &msg);
 665	if (ret < 0) {
 666		goto out;
 667	}
 668
 669	wait_for_completion(&cup->cu_done);
 670
 671	if (msg.errno < 0)
 672		ret = msg.errno;
 673out:
 674	return ret;
 675}
 676
 677static int
 678cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
 679{
 680	int ret;
 681
 682	/*
 683	 * -EAGAIN occurs when pipe is closed and reopened while there are
 684	 *  upcalls queued.
 685	 */
 686	do {
 687		ret = __cld_pipe_upcall(pipe, cmsg, nn);
 688	} while (ret == -EAGAIN);
 689
 690	return ret;
 691}
 692
 693static ssize_t
 694__cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
 695		struct nfsd_net *nn)
 696{
 697	uint8_t cmd, princhashlen;
 698	struct xdr_netobj name, princhash = { .len = 0, .data = NULL };
 699	char *namecopy __free(kfree) = NULL;
 700	char *princhashcopy __free(kfree) = NULL;
 701	uint16_t namelen;
 702
 703	if (get_user(cmd, &cmsg->cm_cmd)) {
 704		dprintk("%s: error when copying cmd from userspace", __func__);
 705		return -EFAULT;
 706	}
 707	if (cmd == Cld_GraceStart) {
 708		if (nn->client_tracking_ops->version >= 2) {
 709			const struct cld_clntinfo __user *ci;
 710
 711			ci = &cmsg->cm_u.cm_clntinfo;
 712			if (get_user(namelen, &ci->cc_name.cn_len))
 713				return -EFAULT;
 714			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
 715				dprintk("%s: invalid namelen (%u)", __func__, namelen);
 716				return -EINVAL;
 717			}
 718			namecopy = memdup_user(&ci->cc_name.cn_id, namelen);
 719			if (IS_ERR(namecopy))
 720				return PTR_ERR(namecopy);
 721			name.data = namecopy;
 722			name.len = namelen;
 723			get_user(princhashlen, &ci->cc_princhash.cp_len);
 724			if (princhashlen > 0) {
 725				princhashcopy = memdup_user(
 726					&ci->cc_princhash.cp_data,
 727					princhashlen);
 728				if (IS_ERR(princhashcopy))
 729					return PTR_ERR(princhashcopy);
 730				princhash.data = princhashcopy;
 731				princhash.len = princhashlen;
 732			} else
 733				princhash.len = 0;
 734		} else {
 735			const struct cld_name __user *cnm;
 736
 737			cnm = &cmsg->cm_u.cm_name;
 738			if (get_user(namelen, &cnm->cn_len))
 739				return -EFAULT;
 740			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
 741				dprintk("%s: invalid namelen (%u)", __func__, namelen);
 742				return -EINVAL;
 743			}
 744			namecopy = memdup_user(&cnm->cn_id, namelen);
 745			if (IS_ERR(namecopy))
 746				return PTR_ERR(namecopy);
 747			name.data = namecopy;
 748			name.len = namelen;
 749		}
 750#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
 751		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
 752			struct cld_net *cn = nn->cld_net;
 753
 754			name.len = name.len - 5;
 755			name.data = name.data + 5;
 756			cn->cn_has_legacy = true;
 757		}
 758#endif
 759		if (!nfs4_client_to_reclaim(name, princhash, nn))
 760			return -EFAULT;
 761		return nn->client_tracking_ops->msglen;
 762	}
 763	return -EFAULT;
 764}
 765
 766static ssize_t
 767cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 768{
 769	struct cld_upcall *tmp, *cup;
 770	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
 771	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
 772	uint32_t xid;
 773	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
 774						nfsd_net_id);
 775	struct cld_net *cn = nn->cld_net;
 776	int16_t status;
 777
 778	if (mlen != nn->client_tracking_ops->msglen) {
 779		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
 780			nn->client_tracking_ops->msglen);
 781		return -EINVAL;
 782	}
 783
 784	/* copy just the xid so we can try to find that */
 785	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
 786		dprintk("%s: error when copying xid from userspace", __func__);
 787		return -EFAULT;
 788	}
 789
 790	/*
 791	 * copy the status so we know whether to remove the upcall from the
 792	 * list (for -EINPROGRESS, we just want to make sure the xid is
 793	 * valid, not remove the upcall from the list)
 794	 */
 795	if (get_user(status, &hdr->cm_status)) {
 796		dprintk("%s: error when copying status from userspace", __func__);
 797		return -EFAULT;
 798	}
 799
 800	/* walk the list and find corresponding xid */
 801	cup = NULL;
 802	spin_lock(&cn->cn_lock);
 803	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 804		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
 805			cup = tmp;
 806			if (status != -EINPROGRESS)
 807				list_del_init(&cup->cu_list);
 808			break;
 809		}
 810	}
 811	spin_unlock(&cn->cn_lock);
 812
 813	/* couldn't find upcall? */
 814	if (!cup) {
 815		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
 816		return -EINVAL;
 817	}
 818
 819	if (status == -EINPROGRESS)
 820		return __cld_pipe_inprogress_downcall(cmsg, nn);
 821
 822	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
 823		return -EFAULT;
 824
 825	complete(&cup->cu_done);
 826	return mlen;
 827}
 828
 829static void
 830cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 831{
 832	struct cld_msg *cmsg = msg->data;
 833	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
 834						 cu_u.cu_msg);
 835
 836	/* errno >= 0 means we got a downcall */
 837	if (msg->errno >= 0)
 838		return;
 839
 840	complete(&cup->cu_done);
 841}
 842
 843static const struct rpc_pipe_ops cld_upcall_ops = {
 844	.upcall		= rpc_pipe_generic_upcall,
 845	.downcall	= cld_pipe_downcall,
 846	.destroy_msg	= cld_pipe_destroy_msg,
 847};
 848
 849static int
 850nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
 851{
 852	struct dentry *dir;
 853	int err;
 854
 855	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
 856	if (dir == NULL)
 857		return -ENOENT;
 858	err = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
 859	dput(dir);
 860	return err;
 861}
 862
 863static int
 864nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
 865{
 866	struct super_block *sb;
 867	int err;
 868
 869	sb = rpc_get_sb_net(net);
 870	if (!sb)
 871		return 0;
 872	err = nfsd4_cld_register_sb(sb, pipe);
 873	rpc_put_sb_net(net);
 874	return err;
 875}
 876
 877static void
 878nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
 879{
 880	struct super_block *sb;
 881
 882	sb = rpc_get_sb_net(net);
 883	if (sb) {
 884		rpc_unlink(pipe);
 885		rpc_put_sb_net(net);
 886	}
 887}
 888
 889/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
 890static int
 891__nfsd4_init_cld_pipe(struct net *net)
 892{
 893	int ret;
 894	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 895	struct cld_net *cn;
 896
 897	if (nn->cld_net)
 898		return 0;
 899
 900	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
 901	if (!cn) {
 902		ret = -ENOMEM;
 903		goto err;
 904	}
 905
 906	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 907	if (IS_ERR(cn->cn_pipe)) {
 908		ret = PTR_ERR(cn->cn_pipe);
 909		goto err;
 910	}
 911	spin_lock_init(&cn->cn_lock);
 912	INIT_LIST_HEAD(&cn->cn_list);
 913
 914	ret = nfsd4_cld_register_net(net, cn->cn_pipe);
 915	if (unlikely(ret))
 916		goto err_destroy_data;
 917
 918#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
 919	cn->cn_has_legacy = false;
 920#endif
 921	nn->cld_net = cn;
 922	return 0;
 923
 924err_destroy_data:
 925	rpc_destroy_pipe_data(cn->cn_pipe);
 926err:
 927	kfree(cn);
 928	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
 929			ret);
 930	return ret;
 931}
 932
 933static int
 934nfsd4_init_cld_pipe(struct net *net)
 935{
 936	int status;
 937
 938	status = __nfsd4_init_cld_pipe(net);
 939	if (!status)
 940		pr_info("NFSD: Using old nfsdcld client tracking operations.\n");
 941	return status;
 942}
 943
 944static void
 945nfsd4_remove_cld_pipe(struct net *net)
 946{
 947	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 948	struct cld_net *cn = nn->cld_net;
 949
 950	nfsd4_cld_unregister_net(net, cn->cn_pipe);
 951	rpc_destroy_pipe_data(cn->cn_pipe);
 952	kfree(nn->cld_net);
 953	nn->cld_net = NULL;
 954}
 955
 956static struct cld_upcall *
 957alloc_cld_upcall(struct nfsd_net *nn)
 958{
 959	struct cld_upcall *new, *tmp;
 960	struct cld_net *cn = nn->cld_net;
 961
 962	new = kzalloc(sizeof(*new), GFP_KERNEL);
 963	if (!new)
 964		return new;
 965
 966	/* FIXME: hard cap on number in flight? */
 967restart_search:
 968	spin_lock(&cn->cn_lock);
 969	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 970		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
 971			cn->cn_xid++;
 972			spin_unlock(&cn->cn_lock);
 973			goto restart_search;
 974		}
 975	}
 976	init_completion(&new->cu_done);
 977	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
 978	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
 979	new->cu_net = cn;
 980	list_add(&new->cu_list, &cn->cn_list);
 981	spin_unlock(&cn->cn_lock);
 982
 983	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
 984
 985	return new;
 986}
 987
 988static void
 989free_cld_upcall(struct cld_upcall *victim)
 990{
 991	struct cld_net *cn = victim->cu_net;
 992
 993	spin_lock(&cn->cn_lock);
 994	list_del(&victim->cu_list);
 995	spin_unlock(&cn->cn_lock);
 996	kfree(victim);
 997}
 998
 999/* Ask daemon to create a new record */
1000static void
1001nfsd4_cld_create(struct nfs4_client *clp)
1002{
1003	int ret;
1004	struct cld_upcall *cup;
1005	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1006	struct cld_net *cn = nn->cld_net;
1007
1008	/* Don't upcall if it's already stored */
1009	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1010		return;
1011
1012	cup = alloc_cld_upcall(nn);
1013	if (!cup) {
1014		ret = -ENOMEM;
1015		goto out_err;
1016	}
1017
1018	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
1019	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1020	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1021			clp->cl_name.len);
1022
1023	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1024	if (!ret) {
1025		ret = cup->cu_u.cu_msg.cm_status;
1026		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1027	}
1028
1029	free_cld_upcall(cup);
1030out_err:
1031	if (ret)
1032		printk(KERN_ERR "NFSD: Unable to create client "
1033				"record on stable storage: %d\n", ret);
1034}
1035
1036/* Ask daemon to create a new record */
1037static void
1038nfsd4_cld_create_v2(struct nfs4_client *clp)
1039{
1040	int ret;
1041	struct cld_upcall *cup;
1042	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1043	struct cld_net *cn = nn->cld_net;
1044	struct cld_msg_v2 *cmsg;
1045	char *principal = NULL;
1046
1047	/* Don't upcall if it's already stored */
1048	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1049		return;
1050
1051	cup = alloc_cld_upcall(nn);
1052	if (!cup) {
1053		ret = -ENOMEM;
1054		goto out_err;
1055	}
1056
1057	cmsg = &cup->cu_u.cu_msg_v2;
1058	cmsg->cm_cmd = Cld_Create;
1059	cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len;
1060	memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data,
1061			clp->cl_name.len);
1062	if (clp->cl_cred.cr_raw_principal)
1063		principal = clp->cl_cred.cr_raw_principal;
1064	else if (clp->cl_cred.cr_principal)
1065		principal = clp->cl_cred.cr_principal;
1066	if (principal) {
1067		sha256(principal, strlen(principal),
1068		       cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data);
1069		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = SHA256_DIGEST_SIZE;
1070	} else
1071		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
1072
1073	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
1074	if (!ret) {
1075		ret = cmsg->cm_status;
1076		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1077	}
1078
1079	free_cld_upcall(cup);
1080out_err:
1081	if (ret)
1082		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
1083				ret);
1084}
1085
1086/* Ask daemon to create a new record */
1087static void
1088nfsd4_cld_remove(struct nfs4_client *clp)
1089{
1090	int ret;
1091	struct cld_upcall *cup;
1092	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1093	struct cld_net *cn = nn->cld_net;
1094
1095	/* Don't upcall if it's already removed */
1096	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1097		return;
1098
1099	cup = alloc_cld_upcall(nn);
1100	if (!cup) {
1101		ret = -ENOMEM;
1102		goto out_err;
1103	}
1104
1105	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
1106	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1107	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1108			clp->cl_name.len);
1109
1110	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1111	if (!ret) {
1112		ret = cup->cu_u.cu_msg.cm_status;
1113		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1114	}
1115
1116	free_cld_upcall(cup);
1117out_err:
1118	if (ret)
1119		printk(KERN_ERR "NFSD: Unable to remove client "
1120				"record from stable storage: %d\n", ret);
1121}
1122
1123/*
1124 * For older nfsdcld's that do not allow us to "slurp" the clients
1125 * from the tracking database during startup.
1126 *
1127 * Check for presence of a record, and update its timestamp
1128 */
1129static int
1130nfsd4_cld_check_v0(struct nfs4_client *clp)
1131{
1132	int ret;
1133	struct cld_upcall *cup;
1134	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1135	struct cld_net *cn = nn->cld_net;
1136
1137	/* Don't upcall if one was already stored during this grace pd */
1138	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1139		return 0;
1140
1141	cup = alloc_cld_upcall(nn);
1142	if (!cup) {
1143		printk(KERN_ERR "NFSD: Unable to check client record on "
1144				"stable storage: %d\n", -ENOMEM);
1145		return -ENOMEM;
1146	}
1147
1148	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
1149	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1150	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1151			clp->cl_name.len);
1152
1153	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1154	if (!ret) {
1155		ret = cup->cu_u.cu_msg.cm_status;
1156		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1157	}
1158
1159	free_cld_upcall(cup);
1160	return ret;
1161}
1162
1163/*
1164 * For newer nfsdcld's that allow us to "slurp" the clients
1165 * from the tracking database during startup.
1166 *
1167 * Check for presence of a record in the reclaim_str_hashtbl
1168 */
1169static int
1170nfsd4_cld_check(struct nfs4_client *clp)
1171{
1172	struct nfs4_client_reclaim *crp;
1173	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1174
1175	/* did we already find that this client is stable? */
1176	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1177		return 0;
1178
1179	/* look for it in the reclaim hashtable otherwise */
1180	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1181	if (crp)
1182		goto found;
1183
1184#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1185	if (nn->cld_net->cn_has_legacy) {
1186		char dname[HEXDIR_LEN];
1187		struct xdr_netobj name;
1188
1189		nfs4_make_rec_clidname(dname, &clp->cl_name);
1190
1191		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1192		if (!name.data) {
1193			dprintk("%s: failed to allocate memory for name.data!\n",
1194				__func__);
1195			return -ENOENT;
1196		}
1197		name.len = HEXDIR_LEN;
1198		crp = nfsd4_find_reclaim_client(name, nn);
1199		kfree(name.data);
1200		if (crp)
1201			goto found;
1202
1203	}
1204#endif
1205	return -ENOENT;
1206found:
1207	crp->cr_clp = clp;
1208	return 0;
1209}
1210
1211static int
1212nfsd4_cld_check_v2(struct nfs4_client *clp)
1213{
1214	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1215#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1216	struct cld_net *cn = nn->cld_net;
1217#endif
1218	struct nfs4_client_reclaim *crp;
1219	char *principal = NULL;
1220
1221	/* did we already find that this client is stable? */
1222	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1223		return 0;
1224
1225	/* look for it in the reclaim hashtable otherwise */
1226	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1227	if (crp)
1228		goto found;
1229
1230#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1231	if (cn->cn_has_legacy) {
1232		struct xdr_netobj name;
1233		char dname[HEXDIR_LEN];
1234
1235		nfs4_make_rec_clidname(dname, &clp->cl_name);
1236
1237		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1238		if (!name.data) {
1239			dprintk("%s: failed to allocate memory for name.data\n",
1240					__func__);
1241			return -ENOENT;
1242		}
1243		name.len = HEXDIR_LEN;
1244		crp = nfsd4_find_reclaim_client(name, nn);
1245		kfree(name.data);
1246		if (crp)
1247			goto found;
1248
1249	}
1250#endif
1251	return -ENOENT;
1252found:
1253	if (crp->cr_princhash.len) {
1254		u8 digest[SHA256_DIGEST_SIZE];
1255
1256		if (clp->cl_cred.cr_raw_principal)
1257			principal = clp->cl_cred.cr_raw_principal;
1258		else if (clp->cl_cred.cr_principal)
1259			principal = clp->cl_cred.cr_principal;
1260		if (principal == NULL)
1261			return -ENOENT;
1262		sha256(principal, strlen(principal), digest);
1263		if (memcmp(crp->cr_princhash.data, digest,
1264				crp->cr_princhash.len))
1265			return -ENOENT;
1266	}
1267	crp->cr_clp = clp;
1268	return 0;
1269}
1270
1271static int
1272nfsd4_cld_grace_start(struct nfsd_net *nn)
1273{
1274	int ret;
1275	struct cld_upcall *cup;
1276	struct cld_net *cn = nn->cld_net;
1277
1278	cup = alloc_cld_upcall(nn);
1279	if (!cup) {
1280		ret = -ENOMEM;
1281		goto out_err;
1282	}
1283
1284	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
1285	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1286	if (!ret)
1287		ret = cup->cu_u.cu_msg.cm_status;
1288
1289	free_cld_upcall(cup);
1290out_err:
1291	if (ret)
1292		dprintk("%s: Unable to get clients from userspace: %d\n",
1293			__func__, ret);
1294	return ret;
1295}
1296
1297/* For older nfsdcld's that need cm_gracetime */
1298static void
1299nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
1300{
1301	int ret;
1302	struct cld_upcall *cup;
1303	struct cld_net *cn = nn->cld_net;
1304
1305	cup = alloc_cld_upcall(nn);
1306	if (!cup) {
1307		ret = -ENOMEM;
1308		goto out_err;
1309	}
1310
1311	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1312	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
1313	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1314	if (!ret)
1315		ret = cup->cu_u.cu_msg.cm_status;
1316
1317	free_cld_upcall(cup);
1318out_err:
1319	if (ret)
1320		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1321}
1322
1323/*
1324 * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
1325 * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
1326 */
1327static void
1328nfsd4_cld_grace_done(struct nfsd_net *nn)
1329{
1330	int ret;
1331	struct cld_upcall *cup;
1332	struct cld_net *cn = nn->cld_net;
1333
1334	cup = alloc_cld_upcall(nn);
1335	if (!cup) {
1336		ret = -ENOMEM;
1337		goto out_err;
1338	}
1339
1340	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1341	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1342	if (!ret)
1343		ret = cup->cu_u.cu_msg.cm_status;
1344
1345	free_cld_upcall(cup);
1346out_err:
1347	nfs4_release_reclaim(nn);
1348	if (ret)
1349		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1350}
1351
1352static int
1353nfs4_cld_state_init(struct net *net)
1354{
1355	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1356	int i;
1357
1358	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
1359						sizeof(struct list_head),
1360						GFP_KERNEL);
1361	if (!nn->reclaim_str_hashtbl)
1362		return -ENOMEM;
1363
1364	for (i = 0; i < CLIENT_HASH_SIZE; i++)
1365		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
1366	nn->reclaim_str_hashtbl_size = 0;
1367	nn->track_reclaim_completes = true;
1368	atomic_set(&nn->nr_reclaim_complete, 0);
1369
1370	return 0;
1371}
1372
1373static void
1374nfs4_cld_state_shutdown(struct net *net)
1375{
1376	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1377
1378	nn->track_reclaim_completes = false;
1379	kfree(nn->reclaim_str_hashtbl);
1380}
1381
1382static bool
1383cld_running(struct nfsd_net *nn)
1384{
1385	struct cld_net *cn = nn->cld_net;
1386	struct rpc_pipe *pipe = cn->cn_pipe;
1387
1388	return pipe->nreaders || pipe->nwriters;
1389}
1390
1391static int
1392nfsd4_cld_get_version(struct nfsd_net *nn)
1393{
1394	int ret = 0;
1395	struct cld_upcall *cup;
1396	struct cld_net *cn = nn->cld_net;
1397	uint8_t version;
1398
1399	cup = alloc_cld_upcall(nn);
1400	if (!cup) {
1401		ret = -ENOMEM;
1402		goto out_err;
1403	}
1404	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
1405	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1406	if (!ret) {
1407		ret = cup->cu_u.cu_msg.cm_status;
1408		if (ret)
1409			goto out_free;
1410		version = cup->cu_u.cu_msg.cm_u.cm_version;
1411		dprintk("%s: userspace returned version %u\n",
1412				__func__, version);
1413		if (version < 1)
1414			version = 1;
1415		else if (version > CLD_UPCALL_VERSION)
1416			version = CLD_UPCALL_VERSION;
1417
1418		switch (version) {
1419		case 1:
1420			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1421			break;
1422		case 2:
1423			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
1424			break;
1425		default:
1426			break;
1427		}
1428	}
1429out_free:
1430	free_cld_upcall(cup);
1431out_err:
1432	if (ret)
1433		dprintk("%s: Unable to get version from userspace: %d\n",
1434			__func__, ret);
1435	return ret;
1436}
1437
1438static int
1439nfsd4_cld_tracking_init(struct net *net)
1440{
1441	int status;
1442	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1443	bool running;
1444	int retries = 10;
1445
1446	status = nfs4_cld_state_init(net);
1447	if (status)
1448		return status;
1449
1450	status = __nfsd4_init_cld_pipe(net);
1451	if (status)
1452		goto err_shutdown;
1453
1454	/*
1455	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
1456	 * queue an upcall unless we know that nfsdcld is running (because we
1457	 * want this to fail fast so that nfsd4_client_tracking_init() can try
1458	 * the next client tracking method).  nfsdcld should already be running
1459	 * before nfsd is started, so the wait here is for nfsdcld to open the
1460	 * pipefs file we just created.
1461	 */
1462	while (!(running = cld_running(nn)) && retries--)
1463		msleep(100);
1464
1465	if (!running) {
1466		status = -ETIMEDOUT;
1467		goto err_remove;
1468	}
1469
1470	status = nfsd4_cld_get_version(nn);
1471	if (status == -EOPNOTSUPP)
1472		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
1473
1474	status = nfsd4_cld_grace_start(nn);
1475	if (status) {
1476		if (status == -EOPNOTSUPP)
1477			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
1478		nfs4_release_reclaim(nn);
1479		goto err_remove;
1480	} else
1481		pr_info("NFSD: Using nfsdcld client tracking operations.\n");
1482	return 0;
1483
1484err_remove:
1485	nfsd4_remove_cld_pipe(net);
1486err_shutdown:
1487	nfs4_cld_state_shutdown(net);
1488	return status;
1489}
1490
1491static void
1492nfsd4_cld_tracking_exit(struct net *net)
1493{
1494	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1495
1496	nfs4_release_reclaim(nn);
1497	nfsd4_remove_cld_pipe(net);
1498	nfs4_cld_state_shutdown(net);
1499}
1500
1501/* For older nfsdcld's */
1502static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
1503	.init		= nfsd4_init_cld_pipe,
1504	.exit		= nfsd4_remove_cld_pipe,
1505	.create		= nfsd4_cld_create,
1506	.remove		= nfsd4_cld_remove,
1507	.check		= nfsd4_cld_check_v0,
1508	.grace_done	= nfsd4_cld_grace_done_v0,
1509	.version	= 1,
1510	.msglen		= sizeof(struct cld_msg),
1511};
1512
1513/* For newer nfsdcld's */
1514static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1515	.init		= nfsd4_cld_tracking_init,
1516	.exit		= nfsd4_cld_tracking_exit,
1517	.create		= nfsd4_cld_create,
1518	.remove		= nfsd4_cld_remove,
1519	.check		= nfsd4_cld_check,
1520	.grace_done	= nfsd4_cld_grace_done,
1521	.version	= 1,
1522	.msglen		= sizeof(struct cld_msg),
1523};
1524
1525/* v2 create/check ops include the principal, if available */
1526static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
1527	.init		= nfsd4_cld_tracking_init,
1528	.exit		= nfsd4_cld_tracking_exit,
1529	.create		= nfsd4_cld_create_v2,
1530	.remove		= nfsd4_cld_remove,
1531	.check		= nfsd4_cld_check_v2,
1532	.grace_done	= nfsd4_cld_grace_done,
1533	.version	= 2,
1534	.msglen		= sizeof(struct cld_msg_v2),
1535};
1536
1537#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1538/* upcall via usermodehelper */
1539static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1540module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1541			S_IRUGO|S_IWUSR);
1542MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1543
1544static bool cltrack_legacy_disable;
1545module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1546MODULE_PARM_DESC(cltrack_legacy_disable,
1547		"Disable legacy recoverydir conversion. Default: false");
1548
1549#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1550#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1551#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1552#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1553
1554static char *
1555nfsd4_cltrack_legacy_topdir(void)
1556{
1557	int copied;
1558	size_t len;
1559	char *result;
1560
1561	if (cltrack_legacy_disable)
1562		return NULL;
1563
1564	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1565		strlen(nfs4_recoverydir()) + 1;
1566
1567	result = kmalloc(len, GFP_KERNEL);
1568	if (!result)
1569		return result;
1570
1571	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1572				nfs4_recoverydir());
1573	if (copied >= len) {
1574		/* just return nothing if output was truncated */
1575		kfree(result);
1576		return NULL;
1577	}
1578
1579	return result;
1580}
1581
1582static char *
1583nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1584{
1585	int copied;
1586	size_t len;
1587	char *result;
1588
1589	if (cltrack_legacy_disable)
1590		return NULL;
1591
1592	/* +1 is for '/' between "topdir" and "recdir" */
1593	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1594		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1595
1596	result = kmalloc(len, GFP_KERNEL);
1597	if (!result)
1598		return result;
1599
1600	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1601				nfs4_recoverydir());
1602	if (copied > (len - HEXDIR_LEN)) {
1603		/* just return nothing if output will be truncated */
1604		kfree(result);
1605		return NULL;
1606	}
1607
1608	nfs4_make_rec_clidname(result + copied, name);
1609
1610	return result;
1611}
1612
1613static char *
1614nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1615{
1616	int copied;
1617	size_t len;
1618	char *result;
1619
1620	/* prefix + Y/N character + terminating NULL */
1621	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1622
1623	result = kmalloc(len, GFP_KERNEL);
1624	if (!result)
1625		return result;
1626
1627	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1628				clp->cl_minorversion ? 'Y' : 'N');
1629	if (copied >= len) {
1630		/* just return nothing if output was truncated */
1631		kfree(result);
1632		return NULL;
1633	}
1634
1635	return result;
1636}
1637
1638static char *
1639nfsd4_cltrack_grace_start(time64_t grace_start)
1640{
1641	int copied;
1642	size_t len;
1643	char *result;
1644
1645	/* prefix + max width of int64_t string + terminating NULL */
1646	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1647
1648	result = kmalloc(len, GFP_KERNEL);
1649	if (!result)
1650		return result;
1651
1652	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
1653				grace_start);
1654	if (copied >= len) {
1655		/* just return nothing if output was truncated */
1656		kfree(result);
1657		return NULL;
1658	}
1659
1660	return result;
1661}
1662
1663static int
1664nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1665{
1666	char *envp[3];
1667	char *argv[4];
1668	int ret;
1669
1670	if (unlikely(!cltrack_prog[0])) {
1671		dprintk("%s: cltrack_prog is disabled\n", __func__);
1672		return -EACCES;
1673	}
1674
1675	dprintk("%s: cmd: %s\n", __func__, cmd);
1676	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1677	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1678	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1679
1680	envp[0] = env0;
1681	envp[1] = env1;
1682	envp[2] = NULL;
1683
1684	argv[0] = (char *)cltrack_prog;
1685	argv[1] = cmd;
1686	argv[2] = arg;
1687	argv[3] = NULL;
1688
1689	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1690	/*
1691	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1692	 * error. The admin can re-enable it on the fly by using sysfs
1693	 * once the problem has been fixed.
1694	 */
1695	if (ret == -ENOENT || ret == -EACCES) {
1696		dprintk("NFSD: %s was not found or isn't executable (%d). "
1697			"Setting cltrack_prog to blank string!",
1698			cltrack_prog, ret);
1699		cltrack_prog[0] = '\0';
1700	}
1701	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1702
1703	return ret;
1704}
1705
1706static char *
1707bin_to_hex_dup(const unsigned char *src, int srclen)
1708{
1709	char *buf;
1710
1711	/* +1 for terminating NULL */
1712	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
1713	if (!buf)
1714		return buf;
1715
1716	bin2hex(buf, src, srclen);
1717	return buf;
1718}
1719
1720static int
1721nfsd4_umh_cltrack_init(struct net *net)
1722{
1723	int ret;
1724	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1725	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1726
1727	/* XXX: The usermode helper s not working in container yet. */
1728	if (net != &init_net) {
1729		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1730		kfree(grace_start);
1731		return -EINVAL;
1732	}
1733
1734	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1735	kfree(grace_start);
1736	if (!ret)
1737		pr_info("NFSD: Using UMH upcall client tracking operations.\n");
1738	return ret;
1739}
1740
1741static void
1742nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1743{
1744	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1745			 TASK_UNINTERRUPTIBLE);
1746}
1747
1748static void
1749nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1750{
1751	clear_and_wake_up_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1752}
1753
1754static void
1755nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1756{
1757	char *hexid, *has_session, *grace_start;
1758	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1759
1760	/*
1761	 * With v4.0 clients, there's little difference in outcome between a
1762	 * create and check operation, and we can end up calling into this
1763	 * function multiple times per client (once for each openowner). So,
1764	 * for v4.0 clients skip upcalling once the client has been recorded
1765	 * on stable storage.
1766	 *
1767	 * For v4.1+ clients, the outcome of the two operations is different,
1768	 * so we must ensure that we upcall for the create operation. v4.1+
1769	 * clients call this on RECLAIM_COMPLETE though, so we should only end
1770	 * up doing a single create upcall per client.
1771	 */
1772	if (clp->cl_minorversion == 0 &&
1773	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1774		return;
1775
1776	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1777	if (!hexid) {
1778		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1779		return;
1780	}
1781
1782	has_session = nfsd4_cltrack_client_has_session(clp);
1783	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1784
1785	nfsd4_cltrack_upcall_lock(clp);
1786	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1787		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1788	nfsd4_cltrack_upcall_unlock(clp);
1789
1790	kfree(has_session);
1791	kfree(grace_start);
1792	kfree(hexid);
1793}
1794
1795static void
1796nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1797{
1798	char *hexid;
1799
1800	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1801		return;
1802
1803	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1804	if (!hexid) {
1805		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1806		return;
1807	}
1808
1809	nfsd4_cltrack_upcall_lock(clp);
1810	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1811	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1812		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1813	nfsd4_cltrack_upcall_unlock(clp);
1814
1815	kfree(hexid);
1816}
1817
1818static int
1819nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1820{
1821	int ret;
1822	char *hexid, *has_session, *legacy;
1823
1824	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1825		return 0;
1826
1827	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1828	if (!hexid) {
1829		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1830		return -ENOMEM;
1831	}
1832
1833	has_session = nfsd4_cltrack_client_has_session(clp);
1834	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1835
1836	nfsd4_cltrack_upcall_lock(clp);
1837	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1838		ret = 0;
1839	} else {
1840		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1841		if (ret == 0)
1842			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1843	}
1844	nfsd4_cltrack_upcall_unlock(clp);
1845	kfree(has_session);
1846	kfree(legacy);
1847	kfree(hexid);
1848
1849	return ret;
1850}
1851
1852static void
1853nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
1854{
1855	char *legacy;
1856	char timestr[22]; /* FIXME: better way to determine max size? */
1857
1858	sprintf(timestr, "%lld", nn->boot_time);
1859	legacy = nfsd4_cltrack_legacy_topdir();
1860	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
1861	kfree(legacy);
1862}
1863
1864static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
1865	.init		= nfsd4_umh_cltrack_init,
1866	.exit		= NULL,
1867	.create		= nfsd4_umh_cltrack_create,
1868	.remove		= nfsd4_umh_cltrack_remove,
1869	.check		= nfsd4_umh_cltrack_check,
1870	.grace_done	= nfsd4_umh_cltrack_grace_done,
1871	.version	= 1,
1872	.msglen		= 0,
1873};
1874
1875static inline int check_for_legacy_methods(int status, struct net *net)
1876{
1877	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1878	struct path path;
1879
1880	/*
1881	 * Next, try the UMH upcall.
1882	 */
1883	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
1884	status = nn->client_tracking_ops->init(net);
1885	if (!status)
1886		return status;
1887
1888	/*
1889	 * Finally, See if the recoverydir exists and is a directory.
1890	 * If it is, then use the legacy ops.
1891	 */
1892	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
1893	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
1894	if (!status) {
1895		status = !d_is_dir(path.dentry);
1896		path_put(&path);
1897		if (status)
1898			return -ENOTDIR;
1899	}
1900	return status;
1901}
1902#else
1903static inline int check_for_legacy_methods(int status, struct net *net)
1904{
1905	return status;
1906}
1907#endif /* CONFIG_LEGACY_NFSD_CLIENT_TRACKING */
1908
1909int
1910nfsd4_client_tracking_init(struct net *net)
1911{
1912	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1913	int status;
1914
1915	/* just run the init if it the method is already decided */
1916	if (nn->client_tracking_ops)
1917		goto do_init;
1918
1919	/* First, try to use nfsdcld */
1920	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1921	status = nn->client_tracking_ops->init(net);
1922	if (!status)
1923		return status;
1924	if (status != -ETIMEDOUT) {
1925		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
1926		status = nn->client_tracking_ops->init(net);
1927		if (!status)
1928			return status;
1929	}
1930
1931	status = check_for_legacy_methods(status, net);
1932	if (status)
1933		goto out;
1934do_init:
1935	status = nn->client_tracking_ops->init(net);
1936out:
1937	if (status) {
1938		pr_warn("NFSD: Unable to initialize client recovery tracking! (%d)\n", status);
1939		pr_warn("NFSD: Is nfsdcld running? If not, enable CONFIG_NFSD_LEGACY_CLIENT_TRACKING.\n");
1940		nn->client_tracking_ops = NULL;
1941	}
1942	return status;
1943}
1944
1945void
1946nfsd4_client_tracking_exit(struct net *net)
1947{
1948	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1949
1950	if (nn->client_tracking_ops) {
1951		if (nn->client_tracking_ops->exit)
1952			nn->client_tracking_ops->exit(net);
1953		nn->client_tracking_ops = NULL;
1954	}
1955}
1956
1957void
1958nfsd4_client_record_create(struct nfs4_client *clp)
1959{
1960	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1961
1962	if (nn->client_tracking_ops)
1963		nn->client_tracking_ops->create(clp);
1964}
1965
1966void
1967nfsd4_client_record_remove(struct nfs4_client *clp)
1968{
1969	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1970
1971	if (nn->client_tracking_ops)
1972		nn->client_tracking_ops->remove(clp);
1973}
1974
1975int
1976nfsd4_client_record_check(struct nfs4_client *clp)
1977{
1978	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1979
1980	if (nn->client_tracking_ops)
1981		return nn->client_tracking_ops->check(clp);
1982
1983	return -EOPNOTSUPP;
1984}
1985
1986void
1987nfsd4_record_grace_done(struct nfsd_net *nn)
1988{
1989	if (nn->client_tracking_ops)
1990		nn->client_tracking_ops->grace_done(nn);
1991}
1992
1993static int
1994rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
1995{
1996	struct super_block *sb = ptr;
1997	struct net *net = sb->s_fs_info;
1998	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1999	struct cld_net *cn = nn->cld_net;
2000	int ret = 0;
2001
2002	if (!try_module_get(THIS_MODULE))
2003		return 0;
2004
2005	if (!cn) {
2006		module_put(THIS_MODULE);
2007		return 0;
2008	}
2009
2010	switch (event) {
2011	case RPC_PIPEFS_MOUNT:
2012		ret = nfsd4_cld_register_sb(sb, cn->cn_pipe);
2013		break;
2014	case RPC_PIPEFS_UMOUNT:
2015		rpc_unlink(cn->cn_pipe);
2016		break;
2017	default:
2018		ret = -ENOTSUPP;
2019		break;
2020	}
2021	module_put(THIS_MODULE);
2022	return ret;
2023}
2024
2025static struct notifier_block nfsd4_cld_block = {
2026	.notifier_call = rpc_pipefs_event,
2027};
2028
2029int
2030register_cld_notifier(void)
2031{
2032	WARN_ON(!nfsd_net_id);
2033	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
2034}
2035
2036void
2037unregister_cld_notifier(void)
2038{
2039	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
2040}