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/hash.h>
  36#include <linux/file.h>
  37#include <linux/slab.h>
  38#include <linux/namei.h>
  39#include <linux/sched.h>
  40#include <linux/fs.h>
  41#include <linux/module.h>
  42#include <net/net_namespace.h>
  43#include <linux/sunrpc/rpc_pipe_fs.h>
  44#include <linux/sunrpc/clnt.h>
  45#include <linux/nfsd/cld.h>
  46
  47#include "nfsd.h"
  48#include "state.h"
  49#include "vfs.h"
  50#include "netns.h"
  51
  52#define NFSDDBG_FACILITY                NFSDDBG_PROC
  53
  54/* Declarations */
  55struct nfsd4_client_tracking_ops {
  56	int (*init)(struct net *);
  57	void (*exit)(struct net *);
  58	void (*create)(struct nfs4_client *);
  59	void (*remove)(struct nfs4_client *);
  60	int (*check)(struct nfs4_client *);
  61	void (*grace_done)(struct nfsd_net *);
  62	uint8_t version;
  63	size_t msglen;
  64};
  65
  66static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops;
  67static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2;
  68
  69/* Globals */
  70static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
  71
  72static int
  73nfs4_save_creds(const struct cred **original_creds)
  74{
  75	struct cred *new;
  76
  77	new = prepare_creds();
  78	if (!new)
  79		return -ENOMEM;
  80
  81	new->fsuid = GLOBAL_ROOT_UID;
  82	new->fsgid = GLOBAL_ROOT_GID;
  83	*original_creds = override_creds(new);
  84	put_cred(new);
  85	return 0;
  86}
  87
  88static void
  89nfs4_reset_creds(const struct cred *original)
  90{
  91	revert_creds(original);
  92}
  93
  94static void
  95md5_to_hex(char *out, char *md5)
  96{
  97	int i;
  98
  99	for (i=0; i<16; i++) {
 100		unsigned char c = md5[i];
 101
 102		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
 103		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
 104	}
 105	*out = '\0';
 106}
 107
 108static int
 109nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
 110{
 111	struct xdr_netobj cksum;
 112	struct crypto_shash *tfm;
 113	int status;
 114
 115	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
 116			clname->len, clname->data);
 117	tfm = crypto_alloc_shash("md5", 0, 0);
 118	if (IS_ERR(tfm)) {
 119		status = PTR_ERR(tfm);
 120		goto out_no_tfm;
 121	}
 122
 123	cksum.len = crypto_shash_digestsize(tfm);
 124	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
 125	if (cksum.data == NULL) {
 126		status = -ENOMEM;
 127 		goto out;
 128	}
 129
 130	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
 131					 cksum.data);
 132	if (status)
 133		goto out;
 134
 135	md5_to_hex(dname, cksum.data);
 136
 137	status = 0;
 138out:
 139	kfree(cksum.data);
 140	crypto_free_shash(tfm);
 141out_no_tfm:
 142	return status;
 143}
 144
 145/*
 146 * If we had an error generating the recdir name for the legacy tracker
 147 * then warn the admin. If the error doesn't appear to be transient,
 148 * then disable recovery tracking.
 149 */
 150static void
 151legacy_recdir_name_error(struct nfs4_client *clp, int error)
 152{
 153	printk(KERN_ERR "NFSD: unable to generate recoverydir "
 154			"name (%d).\n", error);
 155
 156	/*
 157	 * if the algorithm just doesn't exist, then disable the recovery
 158	 * tracker altogether. The crypto libs will generally return this if
 159	 * FIPS is enabled as well.
 160	 */
 161	if (error == -ENOENT) {
 162		printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
 163			"Reboot recovery will not function correctly!\n");
 164		nfsd4_client_tracking_exit(clp->net);
 165	}
 166}
 167
 168static void
 169__nfsd4_create_reclaim_record_grace(struct nfs4_client *clp,
 170		const char *dname, int len, struct nfsd_net *nn)
 171{
 172	struct xdr_netobj name;
 173	struct xdr_netobj princhash = { .len = 0, .data = NULL };
 174	struct nfs4_client_reclaim *crp;
 175
 176	name.data = kmemdup(dname, len, GFP_KERNEL);
 177	if (!name.data) {
 178		dprintk("%s: failed to allocate memory for name.data!\n",
 179			__func__);
 180		return;
 181	}
 182	name.len = len;
 183	crp = nfs4_client_to_reclaim(name, princhash, nn);
 184	if (!crp) {
 185		kfree(name.data);
 186		return;
 187	}
 188	crp->cr_clp = clp;
 189}
 190
 191static void
 192nfsd4_create_clid_dir(struct nfs4_client *clp)
 193{
 194	const struct cred *original_cred;
 195	char dname[HEXDIR_LEN];
 196	struct dentry *dir, *dentry;
 197	int status;
 198	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 199
 200	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 201		return;
 202	if (!nn->rec_file)
 203		return;
 204
 205	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 206	if (status)
 207		return legacy_recdir_name_error(clp, status);
 208
 209	status = nfs4_save_creds(&original_cred);
 210	if (status < 0)
 211		return;
 212
 213	status = mnt_want_write_file(nn->rec_file);
 214	if (status)
 215		goto out_creds;
 216
 217	dir = nn->rec_file->f_path.dentry;
 218	/* lock the parent */
 219	inode_lock(d_inode(dir));
 220
 221	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
 222	if (IS_ERR(dentry)) {
 223		status = PTR_ERR(dentry);
 224		goto out_unlock;
 225	}
 226	if (d_really_is_positive(dentry))
 227		/*
 228		 * In the 4.1 case, where we're called from
 229		 * reclaim_complete(), records from the previous reboot
 230		 * may still be left, so this is OK.
 231		 *
 232		 * In the 4.0 case, we should never get here; but we may
 233		 * as well be forgiving and just succeed silently.
 234		 */
 235		goto out_put;
 236	status = vfs_mkdir(&init_user_ns, d_inode(dir), dentry, S_IRWXU);
 237out_put:
 238	dput(dentry);
 239out_unlock:
 240	inode_unlock(d_inode(dir));
 241	if (status == 0) {
 242		if (nn->in_grace)
 243			__nfsd4_create_reclaim_record_grace(clp, dname,
 244					HEXDIR_LEN, nn);
 245		vfs_fsync(nn->rec_file, 0);
 246	} else {
 247		printk(KERN_ERR "NFSD: failed to write recovery record"
 248				" (err %d); please check that %s exists"
 249				" and is writeable", status,
 250				user_recovery_dirname);
 251	}
 252	mnt_drop_write_file(nn->rec_file);
 253out_creds:
 254	nfs4_reset_creds(original_cred);
 255}
 256
 257typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
 258
 259struct name_list {
 260	char name[HEXDIR_LEN];
 261	struct list_head list;
 262};
 263
 264struct nfs4_dir_ctx {
 265	struct dir_context ctx;
 266	struct list_head names;
 267};
 268
 269static bool
 270nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
 271		loff_t offset, u64 ino, unsigned int d_type)
 272{
 273	struct nfs4_dir_ctx *ctx =
 274		container_of(__ctx, struct nfs4_dir_ctx, ctx);
 275	struct name_list *entry;
 276
 277	if (namlen != HEXDIR_LEN - 1)
 278		return true;
 279	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
 280	if (entry == NULL)
 281		return false;
 282	memcpy(entry->name, name, HEXDIR_LEN - 1);
 283	entry->name[HEXDIR_LEN - 1] = '\0';
 284	list_add(&entry->list, &ctx->names);
 285	return true;
 286}
 287
 288static int
 289nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
 290{
 291	const struct cred *original_cred;
 292	struct dentry *dir = nn->rec_file->f_path.dentry;
 293	struct nfs4_dir_ctx ctx = {
 294		.ctx.actor = nfsd4_build_namelist,
 295		.names = LIST_HEAD_INIT(ctx.names)
 296	};
 297	struct name_list *entry, *tmp;
 298	int status;
 299
 300	status = nfs4_save_creds(&original_cred);
 301	if (status < 0)
 302		return status;
 303
 304	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
 305	if (status < 0) {
 306		nfs4_reset_creds(original_cred);
 307		return status;
 308	}
 309
 310	status = iterate_dir(nn->rec_file, &ctx.ctx);
 311	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 312
 313	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 314		if (!status) {
 315			struct dentry *dentry;
 316			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
 317			if (IS_ERR(dentry)) {
 318				status = PTR_ERR(dentry);
 319				break;
 320			}
 321			status = f(dir, dentry, nn);
 322			dput(dentry);
 323		}
 324		list_del(&entry->list);
 325		kfree(entry);
 326	}
 327	inode_unlock(d_inode(dir));
 328	nfs4_reset_creds(original_cred);
 329
 330	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 331		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
 332		list_del(&entry->list);
 333		kfree(entry);
 334	}
 335	return status;
 336}
 337
 338static int
 339nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
 340{
 341	struct dentry *dir, *dentry;
 342	int status;
 343
 344	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
 345
 346	dir = nn->rec_file->f_path.dentry;
 347	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 348	dentry = lookup_one_len(name, dir, namlen);
 349	if (IS_ERR(dentry)) {
 350		status = PTR_ERR(dentry);
 351		goto out_unlock;
 352	}
 353	status = -ENOENT;
 354	if (d_really_is_negative(dentry))
 355		goto out;
 356	status = vfs_rmdir(&init_user_ns, d_inode(dir), dentry);
 357out:
 358	dput(dentry);
 359out_unlock:
 360	inode_unlock(d_inode(dir));
 361	return status;
 362}
 363
 364static void
 365__nfsd4_remove_reclaim_record_grace(const char *dname, int len,
 366		struct nfsd_net *nn)
 367{
 368	struct xdr_netobj name;
 369	struct nfs4_client_reclaim *crp;
 370
 371	name.data = kmemdup(dname, len, GFP_KERNEL);
 372	if (!name.data) {
 373		dprintk("%s: failed to allocate memory for name.data!\n",
 374			__func__);
 375		return;
 376	}
 377	name.len = len;
 378	crp = nfsd4_find_reclaim_client(name, nn);
 379	kfree(name.data);
 380	if (crp)
 381		nfs4_remove_reclaim_record(crp, nn);
 382}
 383
 384static void
 385nfsd4_remove_clid_dir(struct nfs4_client *clp)
 386{
 387	const struct cred *original_cred;
 388	char dname[HEXDIR_LEN];
 389	int status;
 390	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 391
 392	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 393		return;
 394
 395	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 396	if (status)
 397		return legacy_recdir_name_error(clp, status);
 398
 399	status = mnt_want_write_file(nn->rec_file);
 400	if (status)
 401		goto out;
 402	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 403
 404	status = nfs4_save_creds(&original_cred);
 405	if (status < 0)
 406		goto out_drop_write;
 407
 408	status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
 409	nfs4_reset_creds(original_cred);
 410	if (status == 0) {
 411		vfs_fsync(nn->rec_file, 0);
 412		if (nn->in_grace)
 413			__nfsd4_remove_reclaim_record_grace(dname,
 414					HEXDIR_LEN, nn);
 415	}
 416out_drop_write:
 417	mnt_drop_write_file(nn->rec_file);
 418out:
 419	if (status)
 420		printk("NFSD: Failed to remove expired client state directory"
 421				" %.*s\n", HEXDIR_LEN, dname);
 422}
 423
 424static int
 425purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 426{
 427	int status;
 428	struct xdr_netobj name;
 429
 430	if (child->d_name.len != HEXDIR_LEN - 1) {
 431		printk("%s: illegal name %pd in recovery directory\n",
 432				__func__, child);
 433		/* Keep trying; maybe the others are OK: */
 434		return 0;
 435	}
 436	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
 437	if (!name.data) {
 438		dprintk("%s: failed to allocate memory for name.data!\n",
 439			__func__);
 440		goto out;
 441	}
 442	name.len = HEXDIR_LEN;
 443	if (nfs4_has_reclaimed_state(name, nn))
 444		goto out_free;
 445
 446	status = vfs_rmdir(&init_user_ns, d_inode(parent), child);
 447	if (status)
 448		printk("failed to remove client recovery directory %pd\n",
 449				child);
 450out_free:
 451	kfree(name.data);
 452out:
 453	/* Keep trying, success or failure: */
 454	return 0;
 455}
 456
 457static void
 458nfsd4_recdir_purge_old(struct nfsd_net *nn)
 459{
 460	int status;
 461
 462	nn->in_grace = false;
 463	if (!nn->rec_file)
 464		return;
 465	status = mnt_want_write_file(nn->rec_file);
 466	if (status)
 467		goto out;
 468	status = nfsd4_list_rec_dir(purge_old, nn);
 469	if (status == 0)
 470		vfs_fsync(nn->rec_file, 0);
 471	mnt_drop_write_file(nn->rec_file);
 472out:
 473	nfs4_release_reclaim(nn);
 474	if (status)
 475		printk("nfsd4: failed to purge old clients from recovery"
 476			" directory %pD\n", nn->rec_file);
 477}
 478
 479static int
 480load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 481{
 482	struct xdr_netobj name;
 483	struct xdr_netobj princhash = { .len = 0, .data = NULL };
 484
 485	if (child->d_name.len != HEXDIR_LEN - 1) {
 486		printk("%s: illegal name %pd in recovery directory\n",
 487				__func__, child);
 488		/* Keep trying; maybe the others are OK: */
 489		return 0;
 490	}
 491	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
 492	if (!name.data) {
 493		dprintk("%s: failed to allocate memory for name.data!\n",
 494			__func__);
 495		goto out;
 496	}
 497	name.len = HEXDIR_LEN;
 498	if (!nfs4_client_to_reclaim(name, princhash, nn))
 499		kfree(name.data);
 500out:
 501	return 0;
 502}
 503
 504static int
 505nfsd4_recdir_load(struct net *net) {
 506	int status;
 507	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
 508
 509	if (!nn->rec_file)
 510		return 0;
 511
 512	status = nfsd4_list_rec_dir(load_recdir, nn);
 513	if (status)
 514		printk("nfsd4: failed loading clients from recovery"
 515			" directory %pD\n", nn->rec_file);
 516	return status;
 517}
 518
 519/*
 520 * Hold reference to the recovery directory.
 521 */
 522
 523static int
 524nfsd4_init_recdir(struct net *net)
 525{
 526	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 527	const struct cred *original_cred;
 528	int status;
 529
 530	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
 531			user_recovery_dirname);
 532
 533	BUG_ON(nn->rec_file);
 534
 535	status = nfs4_save_creds(&original_cred);
 536	if (status < 0) {
 537		printk("NFSD: Unable to change credentials to find recovery"
 538		       " directory: error %d\n",
 539		       status);
 540		return status;
 541	}
 542
 543	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
 544	if (IS_ERR(nn->rec_file)) {
 545		printk("NFSD: unable to find recovery directory %s\n",
 546				user_recovery_dirname);
 547		status = PTR_ERR(nn->rec_file);
 548		nn->rec_file = NULL;
 549	}
 550
 551	nfs4_reset_creds(original_cred);
 552	if (!status)
 553		nn->in_grace = true;
 554	return status;
 555}
 556
 557static void
 558nfsd4_shutdown_recdir(struct net *net)
 559{
 560	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 561
 562	if (!nn->rec_file)
 563		return;
 564	fput(nn->rec_file);
 565	nn->rec_file = NULL;
 566}
 567
 568static int
 569nfs4_legacy_state_init(struct net *net)
 570{
 571	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 572	int i;
 573
 574	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
 575						sizeof(struct list_head),
 576						GFP_KERNEL);
 577	if (!nn->reclaim_str_hashtbl)
 578		return -ENOMEM;
 579
 580	for (i = 0; i < CLIENT_HASH_SIZE; i++)
 581		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
 582	nn->reclaim_str_hashtbl_size = 0;
 583
 584	return 0;
 585}
 586
 587static void
 588nfs4_legacy_state_shutdown(struct net *net)
 589{
 590	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 591
 592	kfree(nn->reclaim_str_hashtbl);
 593}
 594
 595static int
 596nfsd4_load_reboot_recovery_data(struct net *net)
 597{
 598	int status;
 599
 600	status = nfsd4_init_recdir(net);
 601	if (status)
 602		return status;
 603
 604	status = nfsd4_recdir_load(net);
 605	if (status)
 606		nfsd4_shutdown_recdir(net);
 607
 608	return status;
 609}
 610
 611static int
 612nfsd4_legacy_tracking_init(struct net *net)
 613{
 614	int status;
 615
 616	/* XXX: The legacy code won't work in a container */
 617	if (net != &init_net) {
 618		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
 619		return -EINVAL;
 620	}
 621
 622	status = nfs4_legacy_state_init(net);
 623	if (status)
 624		return status;
 625
 626	status = nfsd4_load_reboot_recovery_data(net);
 627	if (status)
 628		goto err;
 629	pr_info("NFSD: Using legacy client tracking operations.\n");
 630	return 0;
 631
 632err:
 633	nfs4_legacy_state_shutdown(net);
 634	return status;
 635}
 636
 637static void
 638nfsd4_legacy_tracking_exit(struct net *net)
 639{
 640	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 641
 642	nfs4_release_reclaim(nn);
 643	nfsd4_shutdown_recdir(net);
 644	nfs4_legacy_state_shutdown(net);
 645}
 646
 647/*
 648 * Change the NFSv4 recovery directory to recdir.
 649 */
 650int
 651nfs4_reset_recoverydir(char *recdir)
 652{
 653	int status;
 654	struct path path;
 655
 656	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
 657	if (status)
 658		return status;
 659	status = -ENOTDIR;
 660	if (d_is_dir(path.dentry)) {
 661		strcpy(user_recovery_dirname, recdir);
 662		status = 0;
 663	}
 664	path_put(&path);
 665	return status;
 666}
 667
 668char *
 669nfs4_recoverydir(void)
 670{
 671	return user_recovery_dirname;
 672}
 673
 674static int
 675nfsd4_check_legacy_client(struct nfs4_client *clp)
 676{
 677	int status;
 678	char dname[HEXDIR_LEN];
 679	struct nfs4_client_reclaim *crp;
 680	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 681	struct xdr_netobj name;
 682
 683	/* did we already find that this client is stable? */
 684	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 685		return 0;
 686
 687	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 688	if (status) {
 689		legacy_recdir_name_error(clp, status);
 690		return status;
 691	}
 692
 693	/* look for it in the reclaim hashtable otherwise */
 694	name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
 695	if (!name.data) {
 696		dprintk("%s: failed to allocate memory for name.data!\n",
 697			__func__);
 698		goto out_enoent;
 699	}
 700	name.len = HEXDIR_LEN;
 701	crp = nfsd4_find_reclaim_client(name, nn);
 702	kfree(name.data);
 703	if (crp) {
 704		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 705		crp->cr_clp = clp;
 706		return 0;
 707	}
 708
 709out_enoent:
 710	return -ENOENT;
 711}
 712
 713static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
 714	.init		= nfsd4_legacy_tracking_init,
 715	.exit		= nfsd4_legacy_tracking_exit,
 716	.create		= nfsd4_create_clid_dir,
 717	.remove		= nfsd4_remove_clid_dir,
 718	.check		= nfsd4_check_legacy_client,
 719	.grace_done	= nfsd4_recdir_purge_old,
 720	.version	= 1,
 721	.msglen		= 0,
 722};
 723
 724/* Globals */
 725#define NFSD_PIPE_DIR		"nfsd"
 726#define NFSD_CLD_PIPE		"cld"
 727
 728/* per-net-ns structure for holding cld upcall info */
 729struct cld_net {
 730	struct rpc_pipe		*cn_pipe;
 731	spinlock_t		 cn_lock;
 732	struct list_head	 cn_list;
 733	unsigned int		 cn_xid;
 734	bool			 cn_has_legacy;
 735	struct crypto_shash	*cn_tfm;
 736};
 737
 738struct cld_upcall {
 739	struct list_head	 cu_list;
 740	struct cld_net		*cu_net;
 741	struct completion	 cu_done;
 742	union {
 743		struct cld_msg_hdr	 cu_hdr;
 744		struct cld_msg		 cu_msg;
 745		struct cld_msg_v2	 cu_msg_v2;
 746	} cu_u;
 747};
 748
 749static int
 750__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
 751{
 752	int ret;
 753	struct rpc_pipe_msg msg;
 754	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
 755
 756	memset(&msg, 0, sizeof(msg));
 757	msg.data = cmsg;
 758	msg.len = nn->client_tracking_ops->msglen;
 759
 760	ret = rpc_queue_upcall(pipe, &msg);
 761	if (ret < 0) {
 762		goto out;
 763	}
 764
 765	wait_for_completion(&cup->cu_done);
 766
 767	if (msg.errno < 0)
 768		ret = msg.errno;
 769out:
 770	return ret;
 771}
 772
 773static int
 774cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
 775{
 776	int ret;
 777
 778	/*
 779	 * -EAGAIN occurs when pipe is closed and reopened while there are
 780	 *  upcalls queued.
 781	 */
 782	do {
 783		ret = __cld_pipe_upcall(pipe, cmsg, nn);
 784	} while (ret == -EAGAIN);
 785
 786	return ret;
 787}
 788
 789static ssize_t
 790__cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
 791		struct nfsd_net *nn)
 792{
 793	uint8_t cmd, princhashlen;
 794	struct xdr_netobj name, princhash = { .len = 0, .data = NULL };
 795	uint16_t namelen;
 796	struct cld_net *cn = nn->cld_net;
 797
 798	if (get_user(cmd, &cmsg->cm_cmd)) {
 799		dprintk("%s: error when copying cmd from userspace", __func__);
 800		return -EFAULT;
 801	}
 802	if (cmd == Cld_GraceStart) {
 803		if (nn->client_tracking_ops->version >= 2) {
 804			const struct cld_clntinfo __user *ci;
 805
 806			ci = &cmsg->cm_u.cm_clntinfo;
 807			if (get_user(namelen, &ci->cc_name.cn_len))
 808				return -EFAULT;
 809			name.data = memdup_user(&ci->cc_name.cn_id, namelen);
 810			if (IS_ERR(name.data))
 811				return PTR_ERR(name.data);
 812			name.len = namelen;
 813			get_user(princhashlen, &ci->cc_princhash.cp_len);
 814			if (princhashlen > 0) {
 815				princhash.data = memdup_user(
 816						&ci->cc_princhash.cp_data,
 817						princhashlen);
 818				if (IS_ERR(princhash.data)) {
 819					kfree(name.data);
 820					return PTR_ERR(princhash.data);
 821				}
 822				princhash.len = princhashlen;
 823			} else
 824				princhash.len = 0;
 825		} else {
 826			const struct cld_name __user *cnm;
 827
 828			cnm = &cmsg->cm_u.cm_name;
 829			if (get_user(namelen, &cnm->cn_len))
 830				return -EFAULT;
 831			name.data = memdup_user(&cnm->cn_id, namelen);
 832			if (IS_ERR(name.data))
 833				return PTR_ERR(name.data);
 834			name.len = namelen;
 835		}
 836		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
 837			name.len = name.len - 5;
 838			memmove(name.data, name.data + 5, name.len);
 839			cn->cn_has_legacy = true;
 840		}
 841		if (!nfs4_client_to_reclaim(name, princhash, nn)) {
 842			kfree(name.data);
 843			kfree(princhash.data);
 844			return -EFAULT;
 845		}
 846		return nn->client_tracking_ops->msglen;
 847	}
 848	return -EFAULT;
 849}
 850
 851static ssize_t
 852cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 853{
 854	struct cld_upcall *tmp, *cup;
 855	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
 856	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
 857	uint32_t xid;
 858	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
 859						nfsd_net_id);
 860	struct cld_net *cn = nn->cld_net;
 861	int16_t status;
 862
 863	if (mlen != nn->client_tracking_ops->msglen) {
 864		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
 865			nn->client_tracking_ops->msglen);
 866		return -EINVAL;
 867	}
 868
 869	/* copy just the xid so we can try to find that */
 870	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
 871		dprintk("%s: error when copying xid from userspace", __func__);
 872		return -EFAULT;
 873	}
 874
 875	/*
 876	 * copy the status so we know whether to remove the upcall from the
 877	 * list (for -EINPROGRESS, we just want to make sure the xid is
 878	 * valid, not remove the upcall from the list)
 879	 */
 880	if (get_user(status, &hdr->cm_status)) {
 881		dprintk("%s: error when copying status from userspace", __func__);
 882		return -EFAULT;
 883	}
 884
 885	/* walk the list and find corresponding xid */
 886	cup = NULL;
 887	spin_lock(&cn->cn_lock);
 888	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 889		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
 890			cup = tmp;
 891			if (status != -EINPROGRESS)
 892				list_del_init(&cup->cu_list);
 893			break;
 894		}
 895	}
 896	spin_unlock(&cn->cn_lock);
 897
 898	/* couldn't find upcall? */
 899	if (!cup) {
 900		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
 901		return -EINVAL;
 902	}
 903
 904	if (status == -EINPROGRESS)
 905		return __cld_pipe_inprogress_downcall(cmsg, nn);
 906
 907	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
 908		return -EFAULT;
 909
 910	complete(&cup->cu_done);
 911	return mlen;
 912}
 913
 914static void
 915cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 916{
 917	struct cld_msg *cmsg = msg->data;
 918	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
 919						 cu_u.cu_msg);
 920
 921	/* errno >= 0 means we got a downcall */
 922	if (msg->errno >= 0)
 923		return;
 924
 925	complete(&cup->cu_done);
 926}
 927
 928static const struct rpc_pipe_ops cld_upcall_ops = {
 929	.upcall		= rpc_pipe_generic_upcall,
 930	.downcall	= cld_pipe_downcall,
 931	.destroy_msg	= cld_pipe_destroy_msg,
 932};
 933
 934static struct dentry *
 935nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
 936{
 937	struct dentry *dir, *dentry;
 938
 939	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
 940	if (dir == NULL)
 941		return ERR_PTR(-ENOENT);
 942	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
 943	dput(dir);
 944	return dentry;
 945}
 946
 947static void
 948nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
 949{
 950	if (pipe->dentry)
 951		rpc_unlink(pipe->dentry);
 952}
 953
 954static struct dentry *
 955nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
 956{
 957	struct super_block *sb;
 958	struct dentry *dentry;
 959
 960	sb = rpc_get_sb_net(net);
 961	if (!sb)
 962		return NULL;
 963	dentry = nfsd4_cld_register_sb(sb, pipe);
 964	rpc_put_sb_net(net);
 965	return dentry;
 966}
 967
 968static void
 969nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
 970{
 971	struct super_block *sb;
 972
 973	sb = rpc_get_sb_net(net);
 974	if (sb) {
 975		nfsd4_cld_unregister_sb(pipe);
 976		rpc_put_sb_net(net);
 977	}
 978}
 979
 980/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
 981static int
 982__nfsd4_init_cld_pipe(struct net *net)
 983{
 984	int ret;
 985	struct dentry *dentry;
 986	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 987	struct cld_net *cn;
 988
 989	if (nn->cld_net)
 990		return 0;
 991
 992	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
 993	if (!cn) {
 994		ret = -ENOMEM;
 995		goto err;
 996	}
 997
 998	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 999	if (IS_ERR(cn->cn_pipe)) {
1000		ret = PTR_ERR(cn->cn_pipe);
1001		goto err;
1002	}
1003	spin_lock_init(&cn->cn_lock);
1004	INIT_LIST_HEAD(&cn->cn_list);
1005
1006	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
1007	if (IS_ERR(dentry)) {
1008		ret = PTR_ERR(dentry);
1009		goto err_destroy_data;
1010	}
1011
1012	cn->cn_pipe->dentry = dentry;
1013	cn->cn_has_legacy = false;
1014	nn->cld_net = cn;
1015	return 0;
1016
1017err_destroy_data:
1018	rpc_destroy_pipe_data(cn->cn_pipe);
1019err:
1020	kfree(cn);
1021	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
1022			ret);
1023	return ret;
1024}
1025
1026static int
1027nfsd4_init_cld_pipe(struct net *net)
1028{
1029	int status;
1030
1031	status = __nfsd4_init_cld_pipe(net);
1032	if (!status)
1033		pr_info("NFSD: Using old nfsdcld client tracking operations.\n");
1034	return status;
1035}
1036
1037static void
1038nfsd4_remove_cld_pipe(struct net *net)
1039{
1040	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1041	struct cld_net *cn = nn->cld_net;
1042
1043	nfsd4_cld_unregister_net(net, cn->cn_pipe);
1044	rpc_destroy_pipe_data(cn->cn_pipe);
1045	if (cn->cn_tfm)
1046		crypto_free_shash(cn->cn_tfm);
1047	kfree(nn->cld_net);
1048	nn->cld_net = NULL;
1049}
1050
1051static struct cld_upcall *
1052alloc_cld_upcall(struct nfsd_net *nn)
1053{
1054	struct cld_upcall *new, *tmp;
1055	struct cld_net *cn = nn->cld_net;
1056
1057	new = kzalloc(sizeof(*new), GFP_KERNEL);
1058	if (!new)
1059		return new;
1060
1061	/* FIXME: hard cap on number in flight? */
1062restart_search:
1063	spin_lock(&cn->cn_lock);
1064	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
1065		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
1066			cn->cn_xid++;
1067			spin_unlock(&cn->cn_lock);
1068			goto restart_search;
1069		}
1070	}
1071	init_completion(&new->cu_done);
1072	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
1073	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
1074	new->cu_net = cn;
1075	list_add(&new->cu_list, &cn->cn_list);
1076	spin_unlock(&cn->cn_lock);
1077
1078	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
1079
1080	return new;
1081}
1082
1083static void
1084free_cld_upcall(struct cld_upcall *victim)
1085{
1086	struct cld_net *cn = victim->cu_net;
1087
1088	spin_lock(&cn->cn_lock);
1089	list_del(&victim->cu_list);
1090	spin_unlock(&cn->cn_lock);
1091	kfree(victim);
1092}
1093
1094/* Ask daemon to create a new record */
1095static void
1096nfsd4_cld_create(struct nfs4_client *clp)
1097{
1098	int ret;
1099	struct cld_upcall *cup;
1100	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1101	struct cld_net *cn = nn->cld_net;
1102
1103	/* Don't upcall if it's already stored */
1104	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1105		return;
1106
1107	cup = alloc_cld_upcall(nn);
1108	if (!cup) {
1109		ret = -ENOMEM;
1110		goto out_err;
1111	}
1112
1113	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
1114	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1115	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1116			clp->cl_name.len);
1117
1118	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1119	if (!ret) {
1120		ret = cup->cu_u.cu_msg.cm_status;
1121		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1122	}
1123
1124	free_cld_upcall(cup);
1125out_err:
1126	if (ret)
1127		printk(KERN_ERR "NFSD: Unable to create client "
1128				"record on stable storage: %d\n", ret);
1129}
1130
1131/* Ask daemon to create a new record */
1132static void
1133nfsd4_cld_create_v2(struct nfs4_client *clp)
1134{
1135	int ret;
1136	struct cld_upcall *cup;
1137	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1138	struct cld_net *cn = nn->cld_net;
1139	struct cld_msg_v2 *cmsg;
1140	struct crypto_shash *tfm = cn->cn_tfm;
1141	struct xdr_netobj cksum;
1142	char *principal = NULL;
1143
1144	/* Don't upcall if it's already stored */
1145	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1146		return;
1147
1148	cup = alloc_cld_upcall(nn);
1149	if (!cup) {
1150		ret = -ENOMEM;
1151		goto out_err;
1152	}
1153
1154	cmsg = &cup->cu_u.cu_msg_v2;
1155	cmsg->cm_cmd = Cld_Create;
1156	cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len;
1157	memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data,
1158			clp->cl_name.len);
1159	if (clp->cl_cred.cr_raw_principal)
1160		principal = clp->cl_cred.cr_raw_principal;
1161	else if (clp->cl_cred.cr_principal)
1162		principal = clp->cl_cred.cr_principal;
1163	if (principal) {
1164		cksum.len = crypto_shash_digestsize(tfm);
1165		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1166		if (cksum.data == NULL) {
1167			ret = -ENOMEM;
1168			goto out;
1169		}
1170		ret = crypto_shash_tfm_digest(tfm, principal, strlen(principal),
1171					      cksum.data);
1172		if (ret) {
1173			kfree(cksum.data);
1174			goto out;
1175		}
1176		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = cksum.len;
1177		memcpy(cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data,
1178		       cksum.data, cksum.len);
1179		kfree(cksum.data);
1180	} else
1181		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
1182
1183	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
1184	if (!ret) {
1185		ret = cmsg->cm_status;
1186		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1187	}
1188
1189out:
1190	free_cld_upcall(cup);
1191out_err:
1192	if (ret)
1193		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
1194				ret);
1195}
1196
1197/* Ask daemon to create a new record */
1198static void
1199nfsd4_cld_remove(struct nfs4_client *clp)
1200{
1201	int ret;
1202	struct cld_upcall *cup;
1203	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1204	struct cld_net *cn = nn->cld_net;
1205
1206	/* Don't upcall if it's already removed */
1207	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1208		return;
1209
1210	cup = alloc_cld_upcall(nn);
1211	if (!cup) {
1212		ret = -ENOMEM;
1213		goto out_err;
1214	}
1215
1216	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
1217	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1218	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1219			clp->cl_name.len);
1220
1221	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1222	if (!ret) {
1223		ret = cup->cu_u.cu_msg.cm_status;
1224		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1225	}
1226
1227	free_cld_upcall(cup);
1228out_err:
1229	if (ret)
1230		printk(KERN_ERR "NFSD: Unable to remove client "
1231				"record from stable storage: %d\n", ret);
1232}
1233
1234/*
1235 * For older nfsdcld's that do not allow us to "slurp" the clients
1236 * from the tracking database during startup.
1237 *
1238 * Check for presence of a record, and update its timestamp
1239 */
1240static int
1241nfsd4_cld_check_v0(struct nfs4_client *clp)
1242{
1243	int ret;
1244	struct cld_upcall *cup;
1245	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1246	struct cld_net *cn = nn->cld_net;
1247
1248	/* Don't upcall if one was already stored during this grace pd */
1249	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1250		return 0;
1251
1252	cup = alloc_cld_upcall(nn);
1253	if (!cup) {
1254		printk(KERN_ERR "NFSD: Unable to check client record on "
1255				"stable storage: %d\n", -ENOMEM);
1256		return -ENOMEM;
1257	}
1258
1259	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
1260	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1261	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1262			clp->cl_name.len);
1263
1264	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1265	if (!ret) {
1266		ret = cup->cu_u.cu_msg.cm_status;
1267		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1268	}
1269
1270	free_cld_upcall(cup);
1271	return ret;
1272}
1273
1274/*
1275 * For newer nfsdcld's that allow us to "slurp" the clients
1276 * from the tracking database during startup.
1277 *
1278 * Check for presence of a record in the reclaim_str_hashtbl
1279 */
1280static int
1281nfsd4_cld_check(struct nfs4_client *clp)
1282{
1283	struct nfs4_client_reclaim *crp;
1284	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1285	struct cld_net *cn = nn->cld_net;
1286	int status;
1287	char dname[HEXDIR_LEN];
1288	struct xdr_netobj name;
1289
1290	/* did we already find that this client is stable? */
1291	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1292		return 0;
1293
1294	/* look for it in the reclaim hashtable otherwise */
1295	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1296	if (crp)
1297		goto found;
1298
1299	if (cn->cn_has_legacy) {
1300		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1301		if (status)
1302			return -ENOENT;
1303
1304		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1305		if (!name.data) {
1306			dprintk("%s: failed to allocate memory for name.data!\n",
1307				__func__);
1308			return -ENOENT;
1309		}
1310		name.len = HEXDIR_LEN;
1311		crp = nfsd4_find_reclaim_client(name, nn);
1312		kfree(name.data);
1313		if (crp)
1314			goto found;
1315
1316	}
1317	return -ENOENT;
1318found:
1319	crp->cr_clp = clp;
1320	return 0;
1321}
1322
1323static int
1324nfsd4_cld_check_v2(struct nfs4_client *clp)
1325{
1326	struct nfs4_client_reclaim *crp;
1327	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1328	struct cld_net *cn = nn->cld_net;
1329	int status;
1330	char dname[HEXDIR_LEN];
1331	struct xdr_netobj name;
1332	struct crypto_shash *tfm = cn->cn_tfm;
1333	struct xdr_netobj cksum;
1334	char *principal = NULL;
1335
1336	/* did we already find that this client is stable? */
1337	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1338		return 0;
1339
1340	/* look for it in the reclaim hashtable otherwise */
1341	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1342	if (crp)
1343		goto found;
1344
1345	if (cn->cn_has_legacy) {
1346		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1347		if (status)
1348			return -ENOENT;
1349
1350		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1351		if (!name.data) {
1352			dprintk("%s: failed to allocate memory for name.data\n",
1353					__func__);
1354			return -ENOENT;
1355		}
1356		name.len = HEXDIR_LEN;
1357		crp = nfsd4_find_reclaim_client(name, nn);
1358		kfree(name.data);
1359		if (crp)
1360			goto found;
1361
1362	}
1363	return -ENOENT;
1364found:
1365	if (crp->cr_princhash.len) {
1366		if (clp->cl_cred.cr_raw_principal)
1367			principal = clp->cl_cred.cr_raw_principal;
1368		else if (clp->cl_cred.cr_principal)
1369			principal = clp->cl_cred.cr_principal;
1370		if (principal == NULL)
1371			return -ENOENT;
1372		cksum.len = crypto_shash_digestsize(tfm);
1373		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1374		if (cksum.data == NULL)
1375			return -ENOENT;
1376		status = crypto_shash_tfm_digest(tfm, principal,
1377						 strlen(principal), cksum.data);
1378		if (status) {
1379			kfree(cksum.data);
1380			return -ENOENT;
1381		}
1382		if (memcmp(crp->cr_princhash.data, cksum.data,
1383				crp->cr_princhash.len)) {
1384			kfree(cksum.data);
1385			return -ENOENT;
1386		}
1387		kfree(cksum.data);
1388	}
1389	crp->cr_clp = clp;
1390	return 0;
1391}
1392
1393static int
1394nfsd4_cld_grace_start(struct nfsd_net *nn)
1395{
1396	int ret;
1397	struct cld_upcall *cup;
1398	struct cld_net *cn = nn->cld_net;
1399
1400	cup = alloc_cld_upcall(nn);
1401	if (!cup) {
1402		ret = -ENOMEM;
1403		goto out_err;
1404	}
1405
1406	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
1407	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1408	if (!ret)
1409		ret = cup->cu_u.cu_msg.cm_status;
1410
1411	free_cld_upcall(cup);
1412out_err:
1413	if (ret)
1414		dprintk("%s: Unable to get clients from userspace: %d\n",
1415			__func__, ret);
1416	return ret;
1417}
1418
1419/* For older nfsdcld's that need cm_gracetime */
1420static void
1421nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
1422{
1423	int ret;
1424	struct cld_upcall *cup;
1425	struct cld_net *cn = nn->cld_net;
1426
1427	cup = alloc_cld_upcall(nn);
1428	if (!cup) {
1429		ret = -ENOMEM;
1430		goto out_err;
1431	}
1432
1433	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1434	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
1435	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1436	if (!ret)
1437		ret = cup->cu_u.cu_msg.cm_status;
1438
1439	free_cld_upcall(cup);
1440out_err:
1441	if (ret)
1442		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1443}
1444
1445/*
1446 * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
1447 * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
1448 */
1449static void
1450nfsd4_cld_grace_done(struct nfsd_net *nn)
1451{
1452	int ret;
1453	struct cld_upcall *cup;
1454	struct cld_net *cn = nn->cld_net;
1455
1456	cup = alloc_cld_upcall(nn);
1457	if (!cup) {
1458		ret = -ENOMEM;
1459		goto out_err;
1460	}
1461
1462	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1463	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1464	if (!ret)
1465		ret = cup->cu_u.cu_msg.cm_status;
1466
1467	free_cld_upcall(cup);
1468out_err:
1469	nfs4_release_reclaim(nn);
1470	if (ret)
1471		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1472}
1473
1474static int
1475nfs4_cld_state_init(struct net *net)
1476{
1477	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1478	int i;
1479
1480	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
1481						sizeof(struct list_head),
1482						GFP_KERNEL);
1483	if (!nn->reclaim_str_hashtbl)
1484		return -ENOMEM;
1485
1486	for (i = 0; i < CLIENT_HASH_SIZE; i++)
1487		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
1488	nn->reclaim_str_hashtbl_size = 0;
1489	nn->track_reclaim_completes = true;
1490	atomic_set(&nn->nr_reclaim_complete, 0);
1491
1492	return 0;
1493}
1494
1495static void
1496nfs4_cld_state_shutdown(struct net *net)
1497{
1498	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1499
1500	nn->track_reclaim_completes = false;
1501	kfree(nn->reclaim_str_hashtbl);
1502}
1503
1504static bool
1505cld_running(struct nfsd_net *nn)
1506{
1507	struct cld_net *cn = nn->cld_net;
1508	struct rpc_pipe *pipe = cn->cn_pipe;
1509
1510	return pipe->nreaders || pipe->nwriters;
1511}
1512
1513static int
1514nfsd4_cld_get_version(struct nfsd_net *nn)
1515{
1516	int ret = 0;
1517	struct cld_upcall *cup;
1518	struct cld_net *cn = nn->cld_net;
1519	uint8_t version;
1520
1521	cup = alloc_cld_upcall(nn);
1522	if (!cup) {
1523		ret = -ENOMEM;
1524		goto out_err;
1525	}
1526	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
1527	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1528	if (!ret) {
1529		ret = cup->cu_u.cu_msg.cm_status;
1530		if (ret)
1531			goto out_free;
1532		version = cup->cu_u.cu_msg.cm_u.cm_version;
1533		dprintk("%s: userspace returned version %u\n",
1534				__func__, version);
1535		if (version < 1)
1536			version = 1;
1537		else if (version > CLD_UPCALL_VERSION)
1538			version = CLD_UPCALL_VERSION;
1539
1540		switch (version) {
1541		case 1:
1542			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1543			break;
1544		case 2:
1545			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
1546			break;
1547		default:
1548			break;
1549		}
1550	}
1551out_free:
1552	free_cld_upcall(cup);
1553out_err:
1554	if (ret)
1555		dprintk("%s: Unable to get version from userspace: %d\n",
1556			__func__, ret);
1557	return ret;
1558}
1559
1560static int
1561nfsd4_cld_tracking_init(struct net *net)
1562{
1563	int status;
1564	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1565	bool running;
1566	int retries = 10;
1567	struct crypto_shash *tfm;
1568
1569	status = nfs4_cld_state_init(net);
1570	if (status)
1571		return status;
1572
1573	status = __nfsd4_init_cld_pipe(net);
1574	if (status)
1575		goto err_shutdown;
1576
1577	/*
1578	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
1579	 * queue an upcall unless we know that nfsdcld is running (because we
1580	 * want this to fail fast so that nfsd4_client_tracking_init() can try
1581	 * the next client tracking method).  nfsdcld should already be running
1582	 * before nfsd is started, so the wait here is for nfsdcld to open the
1583	 * pipefs file we just created.
1584	 */
1585	while (!(running = cld_running(nn)) && retries--)
1586		msleep(100);
1587
1588	if (!running) {
1589		status = -ETIMEDOUT;
1590		goto err_remove;
1591	}
1592	tfm = crypto_alloc_shash("sha256", 0, 0);
1593	if (IS_ERR(tfm)) {
1594		status = PTR_ERR(tfm);
1595		goto err_remove;
1596	}
1597	nn->cld_net->cn_tfm = tfm;
1598
1599	status = nfsd4_cld_get_version(nn);
1600	if (status == -EOPNOTSUPP)
1601		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
1602
1603	status = nfsd4_cld_grace_start(nn);
1604	if (status) {
1605		if (status == -EOPNOTSUPP)
1606			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
1607		nfs4_release_reclaim(nn);
1608		goto err_remove;
1609	} else
1610		pr_info("NFSD: Using nfsdcld client tracking operations.\n");
1611	return 0;
1612
1613err_remove:
1614	nfsd4_remove_cld_pipe(net);
1615err_shutdown:
1616	nfs4_cld_state_shutdown(net);
1617	return status;
1618}
1619
1620static void
1621nfsd4_cld_tracking_exit(struct net *net)
1622{
1623	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1624
1625	nfs4_release_reclaim(nn);
1626	nfsd4_remove_cld_pipe(net);
1627	nfs4_cld_state_shutdown(net);
1628}
1629
1630/* For older nfsdcld's */
1631static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
1632	.init		= nfsd4_init_cld_pipe,
1633	.exit		= nfsd4_remove_cld_pipe,
1634	.create		= nfsd4_cld_create,
1635	.remove		= nfsd4_cld_remove,
1636	.check		= nfsd4_cld_check_v0,
1637	.grace_done	= nfsd4_cld_grace_done_v0,
1638	.version	= 1,
1639	.msglen		= sizeof(struct cld_msg),
1640};
1641
1642/* For newer nfsdcld's */
1643static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1644	.init		= nfsd4_cld_tracking_init,
1645	.exit		= nfsd4_cld_tracking_exit,
1646	.create		= nfsd4_cld_create,
1647	.remove		= nfsd4_cld_remove,
1648	.check		= nfsd4_cld_check,
1649	.grace_done	= nfsd4_cld_grace_done,
1650	.version	= 1,
1651	.msglen		= sizeof(struct cld_msg),
1652};
1653
1654/* v2 create/check ops include the principal, if available */
1655static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
1656	.init		= nfsd4_cld_tracking_init,
1657	.exit		= nfsd4_cld_tracking_exit,
1658	.create		= nfsd4_cld_create_v2,
1659	.remove		= nfsd4_cld_remove,
1660	.check		= nfsd4_cld_check_v2,
1661	.grace_done	= nfsd4_cld_grace_done,
1662	.version	= 2,
1663	.msglen		= sizeof(struct cld_msg_v2),
1664};
1665
1666/* upcall via usermodehelper */
1667static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1668module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1669			S_IRUGO|S_IWUSR);
1670MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1671
1672static bool cltrack_legacy_disable;
1673module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1674MODULE_PARM_DESC(cltrack_legacy_disable,
1675		"Disable legacy recoverydir conversion. Default: false");
1676
1677#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1678#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1679#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1680#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1681
1682static char *
1683nfsd4_cltrack_legacy_topdir(void)
1684{
1685	int copied;
1686	size_t len;
1687	char *result;
1688
1689	if (cltrack_legacy_disable)
1690		return NULL;
1691
1692	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1693		strlen(nfs4_recoverydir()) + 1;
1694
1695	result = kmalloc(len, GFP_KERNEL);
1696	if (!result)
1697		return result;
1698
1699	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1700				nfs4_recoverydir());
1701	if (copied >= len) {
1702		/* just return nothing if output was truncated */
1703		kfree(result);
1704		return NULL;
1705	}
1706
1707	return result;
1708}
1709
1710static char *
1711nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1712{
1713	int copied;
1714	size_t len;
1715	char *result;
1716
1717	if (cltrack_legacy_disable)
1718		return NULL;
1719
1720	/* +1 is for '/' between "topdir" and "recdir" */
1721	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1722		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1723
1724	result = kmalloc(len, GFP_KERNEL);
1725	if (!result)
1726		return result;
1727
1728	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1729				nfs4_recoverydir());
1730	if (copied > (len - HEXDIR_LEN)) {
1731		/* just return nothing if output will be truncated */
1732		kfree(result);
1733		return NULL;
1734	}
1735
1736	copied = nfs4_make_rec_clidname(result + copied, name);
1737	if (copied) {
1738		kfree(result);
1739		return NULL;
1740	}
1741
1742	return result;
1743}
1744
1745static char *
1746nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1747{
1748	int copied;
1749	size_t len;
1750	char *result;
1751
1752	/* prefix + Y/N character + terminating NULL */
1753	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1754
1755	result = kmalloc(len, GFP_KERNEL);
1756	if (!result)
1757		return result;
1758
1759	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1760				clp->cl_minorversion ? 'Y' : 'N');
1761	if (copied >= len) {
1762		/* just return nothing if output was truncated */
1763		kfree(result);
1764		return NULL;
1765	}
1766
1767	return result;
1768}
1769
1770static char *
1771nfsd4_cltrack_grace_start(time64_t grace_start)
1772{
1773	int copied;
1774	size_t len;
1775	char *result;
1776
1777	/* prefix + max width of int64_t string + terminating NULL */
1778	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1779
1780	result = kmalloc(len, GFP_KERNEL);
1781	if (!result)
1782		return result;
1783
1784	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
1785				grace_start);
1786	if (copied >= len) {
1787		/* just return nothing if output was truncated */
1788		kfree(result);
1789		return NULL;
1790	}
1791
1792	return result;
1793}
1794
1795static int
1796nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1797{
1798	char *envp[3];
1799	char *argv[4];
1800	int ret;
1801
1802	if (unlikely(!cltrack_prog[0])) {
1803		dprintk("%s: cltrack_prog is disabled\n", __func__);
1804		return -EACCES;
1805	}
1806
1807	dprintk("%s: cmd: %s\n", __func__, cmd);
1808	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1809	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1810	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1811
1812	envp[0] = env0;
1813	envp[1] = env1;
1814	envp[2] = NULL;
1815
1816	argv[0] = (char *)cltrack_prog;
1817	argv[1] = cmd;
1818	argv[2] = arg;
1819	argv[3] = NULL;
1820
1821	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1822	/*
1823	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1824	 * error. The admin can re-enable it on the fly by using sysfs
1825	 * once the problem has been fixed.
1826	 */
1827	if (ret == -ENOENT || ret == -EACCES) {
1828		dprintk("NFSD: %s was not found or isn't executable (%d). "
1829			"Setting cltrack_prog to blank string!",
1830			cltrack_prog, ret);
1831		cltrack_prog[0] = '\0';
1832	}
1833	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1834
1835	return ret;
1836}
1837
1838static char *
1839bin_to_hex_dup(const unsigned char *src, int srclen)
1840{
1841	char *buf;
1842
1843	/* +1 for terminating NULL */
1844	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
1845	if (!buf)
1846		return buf;
1847
1848	bin2hex(buf, src, srclen);
1849	return buf;
1850}
1851
1852static int
1853nfsd4_umh_cltrack_init(struct net *net)
1854{
1855	int ret;
1856	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1857	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1858
1859	/* XXX: The usermode helper s not working in container yet. */
1860	if (net != &init_net) {
1861		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1862		kfree(grace_start);
1863		return -EINVAL;
1864	}
1865
1866	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1867	kfree(grace_start);
1868	if (!ret)
1869		pr_info("NFSD: Using UMH upcall client tracking operations.\n");
1870	return ret;
1871}
1872
1873static void
1874nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1875{
1876	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1877			 TASK_UNINTERRUPTIBLE);
1878}
1879
1880static void
1881nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1882{
1883	smp_mb__before_atomic();
1884	clear_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1885	smp_mb__after_atomic();
1886	wake_up_bit(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK);
1887}
1888
1889static void
1890nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1891{
1892	char *hexid, *has_session, *grace_start;
1893	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1894
1895	/*
1896	 * With v4.0 clients, there's little difference in outcome between a
1897	 * create and check operation, and we can end up calling into this
1898	 * function multiple times per client (once for each openowner). So,
1899	 * for v4.0 clients skip upcalling once the client has been recorded
1900	 * on stable storage.
1901	 *
1902	 * For v4.1+ clients, the outcome of the two operations is different,
1903	 * so we must ensure that we upcall for the create operation. v4.1+
1904	 * clients call this on RECLAIM_COMPLETE though, so we should only end
1905	 * up doing a single create upcall per client.
1906	 */
1907	if (clp->cl_minorversion == 0 &&
1908	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1909		return;
1910
1911	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1912	if (!hexid) {
1913		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1914		return;
1915	}
1916
1917	has_session = nfsd4_cltrack_client_has_session(clp);
1918	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1919
1920	nfsd4_cltrack_upcall_lock(clp);
1921	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1922		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1923	nfsd4_cltrack_upcall_unlock(clp);
1924
1925	kfree(has_session);
1926	kfree(grace_start);
1927	kfree(hexid);
1928}
1929
1930static void
1931nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1932{
1933	char *hexid;
1934
1935	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1936		return;
1937
1938	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1939	if (!hexid) {
1940		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1941		return;
1942	}
1943
1944	nfsd4_cltrack_upcall_lock(clp);
1945	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1946	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1947		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1948	nfsd4_cltrack_upcall_unlock(clp);
1949
1950	kfree(hexid);
1951}
1952
1953static int
1954nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1955{
1956	int ret;
1957	char *hexid, *has_session, *legacy;
1958
1959	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1960		return 0;
1961
1962	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1963	if (!hexid) {
1964		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1965		return -ENOMEM;
1966	}
1967
1968	has_session = nfsd4_cltrack_client_has_session(clp);
1969	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1970
1971	nfsd4_cltrack_upcall_lock(clp);
1972	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1973		ret = 0;
1974	} else {
1975		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1976		if (ret == 0)
1977			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1978	}
1979	nfsd4_cltrack_upcall_unlock(clp);
1980	kfree(has_session);
1981	kfree(legacy);
1982	kfree(hexid);
1983
1984	return ret;
1985}
1986
1987static void
1988nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
1989{
1990	char *legacy;
1991	char timestr[22]; /* FIXME: better way to determine max size? */
1992
1993	sprintf(timestr, "%lld", nn->boot_time);
1994	legacy = nfsd4_cltrack_legacy_topdir();
1995	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
1996	kfree(legacy);
1997}
1998
1999static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
2000	.init		= nfsd4_umh_cltrack_init,
2001	.exit		= NULL,
2002	.create		= nfsd4_umh_cltrack_create,
2003	.remove		= nfsd4_umh_cltrack_remove,
2004	.check		= nfsd4_umh_cltrack_check,
2005	.grace_done	= nfsd4_umh_cltrack_grace_done,
2006	.version	= 1,
2007	.msglen		= 0,
2008};
2009
2010int
2011nfsd4_client_tracking_init(struct net *net)
2012{
2013	int status;
2014	struct path path;
2015	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2016
2017	/* just run the init if it the method is already decided */
2018	if (nn->client_tracking_ops)
2019		goto do_init;
2020
2021	/* First, try to use nfsdcld */
2022	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
2023	status = nn->client_tracking_ops->init(net);
2024	if (!status)
2025		return status;
2026	if (status != -ETIMEDOUT) {
2027		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
2028		status = nn->client_tracking_ops->init(net);
2029		if (!status)
2030			return status;
2031	}
2032
2033	/*
2034	 * Next, try the UMH upcall.
2035	 */
2036	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
2037	status = nn->client_tracking_ops->init(net);
2038	if (!status)
2039		return status;
2040
2041	/*
2042	 * Finally, See if the recoverydir exists and is a directory.
2043	 * If it is, then use the legacy ops.
2044	 */
2045	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
2046	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
2047	if (!status) {
2048		status = d_is_dir(path.dentry);
2049		path_put(&path);
2050		if (!status) {
2051			status = -EINVAL;
2052			goto out;
2053		}
2054	}
2055
2056do_init:
2057	status = nn->client_tracking_ops->init(net);
2058out:
2059	if (status) {
2060		printk(KERN_WARNING "NFSD: Unable to initialize client "
2061				    "recovery tracking! (%d)\n", status);
2062		nn->client_tracking_ops = NULL;
2063	}
2064	return status;
2065}
2066
2067void
2068nfsd4_client_tracking_exit(struct net *net)
2069{
2070	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2071
2072	if (nn->client_tracking_ops) {
2073		if (nn->client_tracking_ops->exit)
2074			nn->client_tracking_ops->exit(net);
2075		nn->client_tracking_ops = NULL;
2076	}
2077}
2078
2079void
2080nfsd4_client_record_create(struct nfs4_client *clp)
2081{
2082	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2083
2084	if (nn->client_tracking_ops)
2085		nn->client_tracking_ops->create(clp);
2086}
2087
2088void
2089nfsd4_client_record_remove(struct nfs4_client *clp)
2090{
2091	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2092
2093	if (nn->client_tracking_ops)
2094		nn->client_tracking_ops->remove(clp);
2095}
2096
2097int
2098nfsd4_client_record_check(struct nfs4_client *clp)
2099{
2100	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2101
2102	if (nn->client_tracking_ops)
2103		return nn->client_tracking_ops->check(clp);
2104
2105	return -EOPNOTSUPP;
2106}
2107
2108void
2109nfsd4_record_grace_done(struct nfsd_net *nn)
2110{
2111	if (nn->client_tracking_ops)
2112		nn->client_tracking_ops->grace_done(nn);
2113}
2114
2115static int
2116rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
2117{
2118	struct super_block *sb = ptr;
2119	struct net *net = sb->s_fs_info;
2120	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2121	struct cld_net *cn = nn->cld_net;
2122	struct dentry *dentry;
2123	int ret = 0;
2124
2125	if (!try_module_get(THIS_MODULE))
2126		return 0;
2127
2128	if (!cn) {
2129		module_put(THIS_MODULE);
2130		return 0;
2131	}
2132
2133	switch (event) {
2134	case RPC_PIPEFS_MOUNT:
2135		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
2136		if (IS_ERR(dentry)) {
2137			ret = PTR_ERR(dentry);
2138			break;
2139		}
2140		cn->cn_pipe->dentry = dentry;
2141		break;
2142	case RPC_PIPEFS_UMOUNT:
2143		if (cn->cn_pipe->dentry)
2144			nfsd4_cld_unregister_sb(cn->cn_pipe);
2145		break;
2146	default:
2147		ret = -ENOTSUPP;
2148		break;
2149	}
2150	module_put(THIS_MODULE);
2151	return ret;
2152}
2153
2154static struct notifier_block nfsd4_cld_block = {
2155	.notifier_call = rpc_pipefs_event,
2156};
2157
2158int
2159register_cld_notifier(void)
2160{
2161	WARN_ON(!nfsd_net_id);
2162	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
2163}
2164
2165void
2166unregister_cld_notifier(void)
2167{
2168	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
2169}