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#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
  70/* Globals */
  71static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
  72
  73static int
  74nfs4_save_creds(const struct cred **original_creds)
  75{
  76	struct cred *new;
  77
  78	new = prepare_creds();
  79	if (!new)
  80		return -ENOMEM;
  81
  82	new->fsuid = GLOBAL_ROOT_UID;
  83	new->fsgid = GLOBAL_ROOT_GID;
  84	*original_creds = override_creds(new);
  85	put_cred(new);
  86	return 0;
  87}
  88
  89static void
  90nfs4_reset_creds(const struct cred *original)
  91{
  92	revert_creds(original);
  93}
  94
  95static void
  96md5_to_hex(char *out, char *md5)
  97{
  98	int i;
  99
 100	for (i=0; i<16; i++) {
 101		unsigned char c = md5[i];
 102
 103		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
 104		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
 105	}
 106	*out = '\0';
 107}
 108
 109static int
 110nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
 111{
 112	struct xdr_netobj cksum;
 113	struct crypto_shash *tfm;
 114	int status;
 115
 116	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
 117			clname->len, clname->data);
 118	tfm = crypto_alloc_shash("md5", 0, 0);
 119	if (IS_ERR(tfm)) {
 120		status = PTR_ERR(tfm);
 121		goto out_no_tfm;
 122	}
 123
 124	cksum.len = crypto_shash_digestsize(tfm);
 125	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
 126	if (cksum.data == NULL) {
 127		status = -ENOMEM;
 128 		goto out;
 129	}
 130
 131	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
 132					 cksum.data);
 133	if (status)
 134		goto out;
 135
 136	md5_to_hex(dname, cksum.data);
 137
 138	status = 0;
 139out:
 140	kfree(cksum.data);
 141	crypto_free_shash(tfm);
 142out_no_tfm:
 143	return status;
 144}
 145
 146/*
 147 * If we had an error generating the recdir name for the legacy tracker
 148 * then warn the admin. If the error doesn't appear to be transient,
 149 * then disable recovery tracking.
 150 */
 151static void
 152legacy_recdir_name_error(struct nfs4_client *clp, int error)
 153{
 154	printk(KERN_ERR "NFSD: unable to generate recoverydir "
 155			"name (%d).\n", error);
 156
 157	/*
 158	 * if the algorithm just doesn't exist, then disable the recovery
 159	 * tracker altogether. The crypto libs will generally return this if
 160	 * FIPS is enabled as well.
 161	 */
 162	if (error == -ENOENT) {
 163		printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
 164			"Reboot recovery will not function correctly!\n");
 165		nfsd4_client_tracking_exit(clp->net);
 166	}
 167}
 168
 169static void
 170__nfsd4_create_reclaim_record_grace(struct nfs4_client *clp,
 171		const char *dname, int len, struct nfsd_net *nn)
 172{
 173	struct xdr_netobj name;
 174	struct xdr_netobj princhash = { .len = 0, .data = NULL };
 175	struct nfs4_client_reclaim *crp;
 176
 177	name.data = kmemdup(dname, len, GFP_KERNEL);
 178	if (!name.data) {
 179		dprintk("%s: failed to allocate memory for name.data!\n",
 180			__func__);
 181		return;
 182	}
 183	name.len = len;
 184	crp = nfs4_client_to_reclaim(name, princhash, nn);
 185	if (!crp) {
 186		kfree(name.data);
 187		return;
 188	}
 189	crp->cr_clp = clp;
 190}
 191
 192static void
 193nfsd4_create_clid_dir(struct nfs4_client *clp)
 194{
 195	const struct cred *original_cred;
 196	char dname[HEXDIR_LEN];
 197	struct dentry *dir, *dentry;
 198	int status;
 199	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 200
 201	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 202		return;
 203	if (!nn->rec_file)
 204		return;
 205
 206	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 207	if (status)
 208		return legacy_recdir_name_error(clp, status);
 209
 210	status = nfs4_save_creds(&original_cred);
 211	if (status < 0)
 212		return;
 213
 214	status = mnt_want_write_file(nn->rec_file);
 215	if (status)
 216		goto out_creds;
 217
 218	dir = nn->rec_file->f_path.dentry;
 219	/* lock the parent */
 220	inode_lock(d_inode(dir));
 221
 222	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
 223	if (IS_ERR(dentry)) {
 224		status = PTR_ERR(dentry);
 225		goto out_unlock;
 226	}
 227	if (d_really_is_positive(dentry))
 228		/*
 229		 * In the 4.1 case, where we're called from
 230		 * reclaim_complete(), records from the previous reboot
 231		 * may still be left, so this is OK.
 232		 *
 233		 * In the 4.0 case, we should never get here; but we may
 234		 * as well be forgiving and just succeed silently.
 235		 */
 236		goto out_put;
 237	status = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, S_IRWXU);
 238out_put:
 239	dput(dentry);
 240out_unlock:
 241	inode_unlock(d_inode(dir));
 242	if (status == 0) {
 243		if (nn->in_grace)
 244			__nfsd4_create_reclaim_record_grace(clp, dname,
 245					HEXDIR_LEN, nn);
 246		vfs_fsync(nn->rec_file, 0);
 247	} else {
 248		printk(KERN_ERR "NFSD: failed to write recovery record"
 249				" (err %d); please check that %s exists"
 250				" and is writeable", status,
 251				user_recovery_dirname);
 252	}
 253	mnt_drop_write_file(nn->rec_file);
 254out_creds:
 255	nfs4_reset_creds(original_cred);
 256}
 257
 258typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
 259
 260struct name_list {
 261	char name[HEXDIR_LEN];
 262	struct list_head list;
 263};
 264
 265struct nfs4_dir_ctx {
 266	struct dir_context ctx;
 267	struct list_head names;
 268};
 269
 270static bool
 271nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
 272		loff_t offset, u64 ino, unsigned int d_type)
 273{
 274	struct nfs4_dir_ctx *ctx =
 275		container_of(__ctx, struct nfs4_dir_ctx, ctx);
 276	struct name_list *entry;
 277
 278	if (namlen != HEXDIR_LEN - 1)
 279		return true;
 280	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
 281	if (entry == NULL)
 282		return false;
 283	memcpy(entry->name, name, HEXDIR_LEN - 1);
 284	entry->name[HEXDIR_LEN - 1] = '\0';
 285	list_add(&entry->list, &ctx->names);
 286	return true;
 287}
 288
 289static int
 290nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
 291{
 292	const struct cred *original_cred;
 293	struct dentry *dir = nn->rec_file->f_path.dentry;
 294	struct nfs4_dir_ctx ctx = {
 295		.ctx.actor = nfsd4_build_namelist,
 296		.names = LIST_HEAD_INIT(ctx.names)
 297	};
 298	struct name_list *entry, *tmp;
 299	int status;
 300
 301	status = nfs4_save_creds(&original_cred);
 302	if (status < 0)
 303		return status;
 304
 305	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
 306	if (status < 0) {
 307		nfs4_reset_creds(original_cred);
 308		return status;
 309	}
 310
 311	status = iterate_dir(nn->rec_file, &ctx.ctx);
 312	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 313
 314	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 315		if (!status) {
 316			struct dentry *dentry;
 317			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
 318			if (IS_ERR(dentry)) {
 319				status = PTR_ERR(dentry);
 320				break;
 321			}
 322			status = f(dir, dentry, nn);
 323			dput(dentry);
 324		}
 325		list_del(&entry->list);
 326		kfree(entry);
 327	}
 328	inode_unlock(d_inode(dir));
 329	nfs4_reset_creds(original_cred);
 330
 331	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 332		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
 333		list_del(&entry->list);
 334		kfree(entry);
 335	}
 336	return status;
 337}
 338
 339static int
 340nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
 341{
 342	struct dentry *dir, *dentry;
 343	int status;
 344
 345	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
 346
 347	dir = nn->rec_file->f_path.dentry;
 348	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 349	dentry = lookup_one_len(name, dir, namlen);
 350	if (IS_ERR(dentry)) {
 351		status = PTR_ERR(dentry);
 352		goto out_unlock;
 353	}
 354	status = -ENOENT;
 355	if (d_really_is_negative(dentry))
 356		goto out;
 357	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry);
 358out:
 359	dput(dentry);
 360out_unlock:
 361	inode_unlock(d_inode(dir));
 362	return status;
 363}
 364
 365static void
 366__nfsd4_remove_reclaim_record_grace(const char *dname, int len,
 367		struct nfsd_net *nn)
 368{
 369	struct xdr_netobj name;
 370	struct nfs4_client_reclaim *crp;
 371
 372	name.data = kmemdup(dname, len, GFP_KERNEL);
 373	if (!name.data) {
 374		dprintk("%s: failed to allocate memory for name.data!\n",
 375			__func__);
 376		return;
 377	}
 378	name.len = len;
 379	crp = nfsd4_find_reclaim_client(name, nn);
 380	kfree(name.data);
 381	if (crp)
 382		nfs4_remove_reclaim_record(crp, nn);
 383}
 384
 385static void
 386nfsd4_remove_clid_dir(struct nfs4_client *clp)
 387{
 388	const struct cred *original_cred;
 389	char dname[HEXDIR_LEN];
 390	int status;
 391	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 392
 393	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 394		return;
 395
 396	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 397	if (status)
 398		return legacy_recdir_name_error(clp, status);
 399
 400	status = mnt_want_write_file(nn->rec_file);
 401	if (status)
 402		goto out;
 403	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 404
 405	status = nfs4_save_creds(&original_cred);
 406	if (status < 0)
 407		goto out_drop_write;
 408
 409	status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
 410	nfs4_reset_creds(original_cred);
 411	if (status == 0) {
 412		vfs_fsync(nn->rec_file, 0);
 413		if (nn->in_grace)
 414			__nfsd4_remove_reclaim_record_grace(dname,
 415					HEXDIR_LEN, nn);
 416	}
 417out_drop_write:
 418	mnt_drop_write_file(nn->rec_file);
 419out:
 420	if (status)
 421		printk("NFSD: Failed to remove expired client state directory"
 422				" %.*s\n", HEXDIR_LEN, dname);
 423}
 424
 425static int
 426purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 427{
 428	int status;
 429	struct xdr_netobj name;
 430
 431	if (child->d_name.len != HEXDIR_LEN - 1) {
 432		printk("%s: illegal name %pd in recovery directory\n",
 433				__func__, child);
 434		/* Keep trying; maybe the others are OK: */
 435		return 0;
 436	}
 437	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
 438	if (!name.data) {
 439		dprintk("%s: failed to allocate memory for name.data!\n",
 440			__func__);
 441		goto out;
 442	}
 443	name.len = HEXDIR_LEN;
 444	if (nfs4_has_reclaimed_state(name, nn))
 445		goto out_free;
 446
 447	status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child);
 448	if (status)
 449		printk("failed to remove client recovery directory %pd\n",
 450				child);
 451out_free:
 452	kfree(name.data);
 453out:
 454	/* Keep trying, success or failure: */
 455	return 0;
 456}
 457
 458static void
 459nfsd4_recdir_purge_old(struct nfsd_net *nn)
 460{
 461	int status;
 462
 463	nn->in_grace = false;
 464	if (!nn->rec_file)
 465		return;
 466	status = mnt_want_write_file(nn->rec_file);
 467	if (status)
 468		goto out;
 469	status = nfsd4_list_rec_dir(purge_old, nn);
 470	if (status == 0)
 471		vfs_fsync(nn->rec_file, 0);
 472	mnt_drop_write_file(nn->rec_file);
 473out:
 474	nfs4_release_reclaim(nn);
 475	if (status)
 476		printk("nfsd4: failed to purge old clients from recovery"
 477			" directory %pD\n", nn->rec_file);
 478}
 479
 480static int
 481load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 482{
 483	struct xdr_netobj name;
 484	struct xdr_netobj princhash = { .len = 0, .data = NULL };
 485
 486	if (child->d_name.len != HEXDIR_LEN - 1) {
 487		printk("%s: illegal name %pd in recovery directory\n",
 488				__func__, child);
 489		/* Keep trying; maybe the others are OK: */
 490		return 0;
 491	}
 492	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
 493	if (!name.data) {
 494		dprintk("%s: failed to allocate memory for name.data!\n",
 495			__func__);
 496		goto out;
 497	}
 498	name.len = HEXDIR_LEN;
 499	if (!nfs4_client_to_reclaim(name, princhash, nn))
 500		kfree(name.data);
 501out:
 502	return 0;
 503}
 504
 505static int
 506nfsd4_recdir_load(struct net *net) {
 507	int status;
 508	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
 509
 510	if (!nn->rec_file)
 511		return 0;
 512
 513	status = nfsd4_list_rec_dir(load_recdir, nn);
 514	if (status)
 515		printk("nfsd4: failed loading clients from recovery"
 516			" directory %pD\n", nn->rec_file);
 517	return status;
 518}
 519
 520/*
 521 * Hold reference to the recovery directory.
 522 */
 523
 524static int
 525nfsd4_init_recdir(struct net *net)
 526{
 527	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 528	const struct cred *original_cred;
 529	int status;
 530
 531	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
 532			user_recovery_dirname);
 533
 534	BUG_ON(nn->rec_file);
 535
 536	status = nfs4_save_creds(&original_cred);
 537	if (status < 0) {
 538		printk("NFSD: Unable to change credentials to find recovery"
 539		       " directory: error %d\n",
 540		       status);
 541		return status;
 542	}
 543
 544	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
 545	if (IS_ERR(nn->rec_file)) {
 546		printk("NFSD: unable to find recovery directory %s\n",
 547				user_recovery_dirname);
 548		status = PTR_ERR(nn->rec_file);
 549		nn->rec_file = NULL;
 550	}
 551
 552	nfs4_reset_creds(original_cred);
 553	if (!status)
 554		nn->in_grace = true;
 555	return status;
 556}
 557
 558static void
 559nfsd4_shutdown_recdir(struct net *net)
 560{
 561	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 562
 563	if (!nn->rec_file)
 564		return;
 565	fput(nn->rec_file);
 566	nn->rec_file = NULL;
 567}
 568
 569static int
 570nfs4_legacy_state_init(struct net *net)
 571{
 572	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 573	int i;
 574
 575	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
 576						sizeof(struct list_head),
 577						GFP_KERNEL);
 578	if (!nn->reclaim_str_hashtbl)
 579		return -ENOMEM;
 580
 581	for (i = 0; i < CLIENT_HASH_SIZE; i++)
 582		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
 583	nn->reclaim_str_hashtbl_size = 0;
 584
 585	return 0;
 586}
 587
 588static void
 589nfs4_legacy_state_shutdown(struct net *net)
 590{
 591	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 592
 593	kfree(nn->reclaim_str_hashtbl);
 594}
 595
 596static int
 597nfsd4_load_reboot_recovery_data(struct net *net)
 598{
 599	int status;
 600
 601	status = nfsd4_init_recdir(net);
 602	if (status)
 603		return status;
 604
 605	status = nfsd4_recdir_load(net);
 606	if (status)
 607		nfsd4_shutdown_recdir(net);
 608
 609	return status;
 610}
 611
 612static int
 613nfsd4_legacy_tracking_init(struct net *net)
 614{
 615	int status;
 616
 617	/* XXX: The legacy code won't work in a container */
 618	if (net != &init_net) {
 619		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
 620		return -EINVAL;
 621	}
 622
 623	status = nfs4_legacy_state_init(net);
 624	if (status)
 625		return status;
 626
 627	status = nfsd4_load_reboot_recovery_data(net);
 628	if (status)
 629		goto err;
 630	pr_info("NFSD: Using legacy client tracking operations.\n");
 631	return 0;
 632
 633err:
 634	nfs4_legacy_state_shutdown(net);
 635	return status;
 636}
 637
 638static void
 639nfsd4_legacy_tracking_exit(struct net *net)
 640{
 641	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 642
 643	nfs4_release_reclaim(nn);
 644	nfsd4_shutdown_recdir(net);
 645	nfs4_legacy_state_shutdown(net);
 646}
 647
 648/*
 649 * Change the NFSv4 recovery directory to recdir.
 650 */
 651int
 652nfs4_reset_recoverydir(char *recdir)
 653{
 654	int status;
 655	struct path path;
 656
 657	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
 658	if (status)
 659		return status;
 660	status = -ENOTDIR;
 661	if (d_is_dir(path.dentry)) {
 662		strcpy(user_recovery_dirname, recdir);
 
 663		status = 0;
 664	}
 665	path_put(&path);
 666	return status;
 667}
 668
 669char *
 670nfs4_recoverydir(void)
 671{
 672	return user_recovery_dirname;
 673}
 674
 675static int
 676nfsd4_check_legacy_client(struct nfs4_client *clp)
 677{
 678	int status;
 679	char dname[HEXDIR_LEN];
 680	struct nfs4_client_reclaim *crp;
 681	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 682	struct xdr_netobj name;
 683
 684	/* did we already find that this client is stable? */
 685	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 686		return 0;
 687
 688	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 689	if (status) {
 690		legacy_recdir_name_error(clp, status);
 691		return status;
 692	}
 693
 694	/* look for it in the reclaim hashtable otherwise */
 695	name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
 696	if (!name.data) {
 697		dprintk("%s: failed to allocate memory for name.data!\n",
 698			__func__);
 699		goto out_enoent;
 700	}
 701	name.len = HEXDIR_LEN;
 702	crp = nfsd4_find_reclaim_client(name, nn);
 703	kfree(name.data);
 704	if (crp) {
 705		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 706		crp->cr_clp = clp;
 707		return 0;
 708	}
 709
 710out_enoent:
 711	return -ENOENT;
 712}
 713
 714static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
 715	.init		= nfsd4_legacy_tracking_init,
 716	.exit		= nfsd4_legacy_tracking_exit,
 717	.create		= nfsd4_create_clid_dir,
 718	.remove		= nfsd4_remove_clid_dir,
 719	.check		= nfsd4_check_legacy_client,
 720	.grace_done	= nfsd4_recdir_purge_old,
 721	.version	= 1,
 722	.msglen		= 0,
 723};
 724#endif /* CONFIG_NFSD_LEGACY_CLIENT_TRACKING */
 725
 726/* Globals */
 727#define NFSD_PIPE_DIR		"nfsd"
 728#define NFSD_CLD_PIPE		"cld"
 729
 730/* per-net-ns structure for holding cld upcall info */
 731struct cld_net {
 732	struct rpc_pipe		*cn_pipe;
 733	spinlock_t		 cn_lock;
 734	struct list_head	 cn_list;
 735	unsigned int		 cn_xid;
 736	struct crypto_shash	*cn_tfm;
 737#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
 738	bool			 cn_has_legacy;
 739#endif
 740};
 741
 742struct cld_upcall {
 743	struct list_head	 cu_list;
 744	struct cld_net		*cu_net;
 745	struct completion	 cu_done;
 746	union {
 747		struct cld_msg_hdr	 cu_hdr;
 748		struct cld_msg		 cu_msg;
 749		struct cld_msg_v2	 cu_msg_v2;
 750	} cu_u;
 751};
 752
 753static int
 754__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
 755{
 756	int ret;
 757	struct rpc_pipe_msg msg;
 758	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
 759
 760	memset(&msg, 0, sizeof(msg));
 761	msg.data = cmsg;
 762	msg.len = nn->client_tracking_ops->msglen;
 763
 764	ret = rpc_queue_upcall(pipe, &msg);
 765	if (ret < 0) {
 766		goto out;
 767	}
 768
 769	wait_for_completion(&cup->cu_done);
 770
 771	if (msg.errno < 0)
 772		ret = msg.errno;
 773out:
 774	return ret;
 775}
 776
 777static int
 778cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
 779{
 780	int ret;
 781
 782	/*
 783	 * -EAGAIN occurs when pipe is closed and reopened while there are
 784	 *  upcalls queued.
 785	 */
 786	do {
 787		ret = __cld_pipe_upcall(pipe, cmsg, nn);
 788	} while (ret == -EAGAIN);
 789
 790	return ret;
 791}
 792
 793static ssize_t
 794__cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
 795		struct nfsd_net *nn)
 796{
 797	uint8_t cmd, princhashlen;
 798	struct xdr_netobj name, princhash = { .len = 0, .data = NULL };
 799	uint16_t namelen;
 800
 801	if (get_user(cmd, &cmsg->cm_cmd)) {
 802		dprintk("%s: error when copying cmd from userspace", __func__);
 803		return -EFAULT;
 804	}
 805	if (cmd == Cld_GraceStart) {
 806		if (nn->client_tracking_ops->version >= 2) {
 807			const struct cld_clntinfo __user *ci;
 808
 809			ci = &cmsg->cm_u.cm_clntinfo;
 810			if (get_user(namelen, &ci->cc_name.cn_len))
 811				return -EFAULT;
 
 
 
 
 812			name.data = memdup_user(&ci->cc_name.cn_id, namelen);
 813			if (IS_ERR(name.data))
 814				return PTR_ERR(name.data);
 815			name.len = namelen;
 816			get_user(princhashlen, &ci->cc_princhash.cp_len);
 817			if (princhashlen > 0) {
 818				princhash.data = memdup_user(
 819						&ci->cc_princhash.cp_data,
 820						princhashlen);
 821				if (IS_ERR(princhash.data)) {
 822					kfree(name.data);
 823					return PTR_ERR(princhash.data);
 824				}
 825				princhash.len = princhashlen;
 826			} else
 827				princhash.len = 0;
 828		} else {
 829			const struct cld_name __user *cnm;
 830
 831			cnm = &cmsg->cm_u.cm_name;
 832			if (get_user(namelen, &cnm->cn_len))
 833				return -EFAULT;
 
 
 
 
 834			name.data = memdup_user(&cnm->cn_id, namelen);
 835			if (IS_ERR(name.data))
 836				return PTR_ERR(name.data);
 837			name.len = namelen;
 838		}
 839#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
 840		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
 841			struct cld_net *cn = nn->cld_net;
 842
 843			name.len = name.len - 5;
 844			memmove(name.data, name.data + 5, name.len);
 845			cn->cn_has_legacy = true;
 846		}
 847#endif
 848		if (!nfs4_client_to_reclaim(name, princhash, nn)) {
 849			kfree(name.data);
 850			kfree(princhash.data);
 851			return -EFAULT;
 852		}
 853		return nn->client_tracking_ops->msglen;
 854	}
 855	return -EFAULT;
 856}
 857
 858static ssize_t
 859cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 860{
 861	struct cld_upcall *tmp, *cup;
 862	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
 863	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
 864	uint32_t xid;
 865	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
 866						nfsd_net_id);
 867	struct cld_net *cn = nn->cld_net;
 868	int16_t status;
 869
 870	if (mlen != nn->client_tracking_ops->msglen) {
 871		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
 872			nn->client_tracking_ops->msglen);
 873		return -EINVAL;
 874	}
 875
 876	/* copy just the xid so we can try to find that */
 877	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
 878		dprintk("%s: error when copying xid from userspace", __func__);
 879		return -EFAULT;
 880	}
 881
 882	/*
 883	 * copy the status so we know whether to remove the upcall from the
 884	 * list (for -EINPROGRESS, we just want to make sure the xid is
 885	 * valid, not remove the upcall from the list)
 886	 */
 887	if (get_user(status, &hdr->cm_status)) {
 888		dprintk("%s: error when copying status from userspace", __func__);
 889		return -EFAULT;
 890	}
 891
 892	/* walk the list and find corresponding xid */
 893	cup = NULL;
 894	spin_lock(&cn->cn_lock);
 895	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 896		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
 897			cup = tmp;
 898			if (status != -EINPROGRESS)
 899				list_del_init(&cup->cu_list);
 900			break;
 901		}
 902	}
 903	spin_unlock(&cn->cn_lock);
 904
 905	/* couldn't find upcall? */
 906	if (!cup) {
 907		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
 908		return -EINVAL;
 909	}
 910
 911	if (status == -EINPROGRESS)
 912		return __cld_pipe_inprogress_downcall(cmsg, nn);
 913
 914	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
 915		return -EFAULT;
 916
 917	complete(&cup->cu_done);
 918	return mlen;
 919}
 920
 921static void
 922cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 923{
 924	struct cld_msg *cmsg = msg->data;
 925	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
 926						 cu_u.cu_msg);
 927
 928	/* errno >= 0 means we got a downcall */
 929	if (msg->errno >= 0)
 930		return;
 931
 932	complete(&cup->cu_done);
 933}
 934
 935static const struct rpc_pipe_ops cld_upcall_ops = {
 936	.upcall		= rpc_pipe_generic_upcall,
 937	.downcall	= cld_pipe_downcall,
 938	.destroy_msg	= cld_pipe_destroy_msg,
 939};
 940
 941static struct dentry *
 942nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
 943{
 944	struct dentry *dir, *dentry;
 945
 946	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
 947	if (dir == NULL)
 948		return ERR_PTR(-ENOENT);
 949	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
 950	dput(dir);
 951	return dentry;
 952}
 953
 954static void
 955nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
 956{
 957	if (pipe->dentry)
 958		rpc_unlink(pipe->dentry);
 959}
 960
 961static struct dentry *
 962nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
 963{
 964	struct super_block *sb;
 965	struct dentry *dentry;
 966
 967	sb = rpc_get_sb_net(net);
 968	if (!sb)
 969		return NULL;
 970	dentry = nfsd4_cld_register_sb(sb, pipe);
 971	rpc_put_sb_net(net);
 972	return dentry;
 973}
 974
 975static void
 976nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
 977{
 978	struct super_block *sb;
 979
 980	sb = rpc_get_sb_net(net);
 981	if (sb) {
 982		nfsd4_cld_unregister_sb(pipe);
 983		rpc_put_sb_net(net);
 984	}
 985}
 986
 987/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
 988static int
 989__nfsd4_init_cld_pipe(struct net *net)
 990{
 991	int ret;
 992	struct dentry *dentry;
 993	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 994	struct cld_net *cn;
 995
 996	if (nn->cld_net)
 997		return 0;
 998
 999	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
1000	if (!cn) {
1001		ret = -ENOMEM;
1002		goto err;
1003	}
1004
1005	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
1006	if (IS_ERR(cn->cn_pipe)) {
1007		ret = PTR_ERR(cn->cn_pipe);
1008		goto err;
1009	}
1010	spin_lock_init(&cn->cn_lock);
1011	INIT_LIST_HEAD(&cn->cn_list);
1012
1013	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
1014	if (IS_ERR(dentry)) {
1015		ret = PTR_ERR(dentry);
1016		goto err_destroy_data;
1017	}
1018
1019	cn->cn_pipe->dentry = dentry;
1020#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1021	cn->cn_has_legacy = false;
1022#endif
1023	nn->cld_net = cn;
1024	return 0;
1025
1026err_destroy_data:
1027	rpc_destroy_pipe_data(cn->cn_pipe);
1028err:
1029	kfree(cn);
1030	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
1031			ret);
1032	return ret;
1033}
1034
1035static int
1036nfsd4_init_cld_pipe(struct net *net)
1037{
1038	int status;
1039
1040	status = __nfsd4_init_cld_pipe(net);
1041	if (!status)
1042		pr_info("NFSD: Using old nfsdcld client tracking operations.\n");
1043	return status;
1044}
1045
1046static void
1047nfsd4_remove_cld_pipe(struct net *net)
1048{
1049	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1050	struct cld_net *cn = nn->cld_net;
1051
1052	nfsd4_cld_unregister_net(net, cn->cn_pipe);
1053	rpc_destroy_pipe_data(cn->cn_pipe);
1054	if (cn->cn_tfm)
1055		crypto_free_shash(cn->cn_tfm);
1056	kfree(nn->cld_net);
1057	nn->cld_net = NULL;
1058}
1059
1060static struct cld_upcall *
1061alloc_cld_upcall(struct nfsd_net *nn)
1062{
1063	struct cld_upcall *new, *tmp;
1064	struct cld_net *cn = nn->cld_net;
1065
1066	new = kzalloc(sizeof(*new), GFP_KERNEL);
1067	if (!new)
1068		return new;
1069
1070	/* FIXME: hard cap on number in flight? */
1071restart_search:
1072	spin_lock(&cn->cn_lock);
1073	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
1074		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
1075			cn->cn_xid++;
1076			spin_unlock(&cn->cn_lock);
1077			goto restart_search;
1078		}
1079	}
1080	init_completion(&new->cu_done);
1081	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
1082	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
1083	new->cu_net = cn;
1084	list_add(&new->cu_list, &cn->cn_list);
1085	spin_unlock(&cn->cn_lock);
1086
1087	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
1088
1089	return new;
1090}
1091
1092static void
1093free_cld_upcall(struct cld_upcall *victim)
1094{
1095	struct cld_net *cn = victim->cu_net;
1096
1097	spin_lock(&cn->cn_lock);
1098	list_del(&victim->cu_list);
1099	spin_unlock(&cn->cn_lock);
1100	kfree(victim);
1101}
1102
1103/* Ask daemon to create a new record */
1104static void
1105nfsd4_cld_create(struct nfs4_client *clp)
1106{
1107	int ret;
1108	struct cld_upcall *cup;
1109	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1110	struct cld_net *cn = nn->cld_net;
1111
1112	/* Don't upcall if it's already stored */
1113	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1114		return;
1115
1116	cup = alloc_cld_upcall(nn);
1117	if (!cup) {
1118		ret = -ENOMEM;
1119		goto out_err;
1120	}
1121
1122	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
1123	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1124	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1125			clp->cl_name.len);
1126
1127	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1128	if (!ret) {
1129		ret = cup->cu_u.cu_msg.cm_status;
1130		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1131	}
1132
1133	free_cld_upcall(cup);
1134out_err:
1135	if (ret)
1136		printk(KERN_ERR "NFSD: Unable to create client "
1137				"record on stable storage: %d\n", ret);
1138}
1139
1140/* Ask daemon to create a new record */
1141static void
1142nfsd4_cld_create_v2(struct nfs4_client *clp)
1143{
1144	int ret;
1145	struct cld_upcall *cup;
1146	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1147	struct cld_net *cn = nn->cld_net;
1148	struct cld_msg_v2 *cmsg;
1149	struct crypto_shash *tfm = cn->cn_tfm;
1150	struct xdr_netobj cksum;
1151	char *principal = NULL;
1152
1153	/* Don't upcall if it's already stored */
1154	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1155		return;
1156
1157	cup = alloc_cld_upcall(nn);
1158	if (!cup) {
1159		ret = -ENOMEM;
1160		goto out_err;
1161	}
1162
1163	cmsg = &cup->cu_u.cu_msg_v2;
1164	cmsg->cm_cmd = Cld_Create;
1165	cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len;
1166	memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data,
1167			clp->cl_name.len);
1168	if (clp->cl_cred.cr_raw_principal)
1169		principal = clp->cl_cred.cr_raw_principal;
1170	else if (clp->cl_cred.cr_principal)
1171		principal = clp->cl_cred.cr_principal;
1172	if (principal) {
1173		cksum.len = crypto_shash_digestsize(tfm);
1174		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1175		if (cksum.data == NULL) {
1176			ret = -ENOMEM;
1177			goto out;
1178		}
1179		ret = crypto_shash_tfm_digest(tfm, principal, strlen(principal),
1180					      cksum.data);
1181		if (ret) {
1182			kfree(cksum.data);
1183			goto out;
1184		}
1185		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = cksum.len;
1186		memcpy(cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data,
1187		       cksum.data, cksum.len);
1188		kfree(cksum.data);
1189	} else
1190		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
1191
1192	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
1193	if (!ret) {
1194		ret = cmsg->cm_status;
1195		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1196	}
1197
1198out:
1199	free_cld_upcall(cup);
1200out_err:
1201	if (ret)
1202		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
1203				ret);
1204}
1205
1206/* Ask daemon to create a new record */
1207static void
1208nfsd4_cld_remove(struct nfs4_client *clp)
1209{
1210	int ret;
1211	struct cld_upcall *cup;
1212	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1213	struct cld_net *cn = nn->cld_net;
1214
1215	/* Don't upcall if it's already removed */
1216	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1217		return;
1218
1219	cup = alloc_cld_upcall(nn);
1220	if (!cup) {
1221		ret = -ENOMEM;
1222		goto out_err;
1223	}
1224
1225	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
1226	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1227	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1228			clp->cl_name.len);
1229
1230	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1231	if (!ret) {
1232		ret = cup->cu_u.cu_msg.cm_status;
1233		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1234	}
1235
1236	free_cld_upcall(cup);
1237out_err:
1238	if (ret)
1239		printk(KERN_ERR "NFSD: Unable to remove client "
1240				"record from stable storage: %d\n", ret);
1241}
1242
1243/*
1244 * For older nfsdcld's that do not allow us to "slurp" the clients
1245 * from the tracking database during startup.
1246 *
1247 * Check for presence of a record, and update its timestamp
1248 */
1249static int
1250nfsd4_cld_check_v0(struct nfs4_client *clp)
1251{
1252	int ret;
1253	struct cld_upcall *cup;
1254	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1255	struct cld_net *cn = nn->cld_net;
1256
1257	/* Don't upcall if one was already stored during this grace pd */
1258	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1259		return 0;
1260
1261	cup = alloc_cld_upcall(nn);
1262	if (!cup) {
1263		printk(KERN_ERR "NFSD: Unable to check client record on "
1264				"stable storage: %d\n", -ENOMEM);
1265		return -ENOMEM;
1266	}
1267
1268	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
1269	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1270	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1271			clp->cl_name.len);
1272
1273	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1274	if (!ret) {
1275		ret = cup->cu_u.cu_msg.cm_status;
1276		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1277	}
1278
1279	free_cld_upcall(cup);
1280	return ret;
1281}
1282
1283/*
1284 * For newer nfsdcld's that allow us to "slurp" the clients
1285 * from the tracking database during startup.
1286 *
1287 * Check for presence of a record in the reclaim_str_hashtbl
1288 */
1289static int
1290nfsd4_cld_check(struct nfs4_client *clp)
1291{
1292	struct nfs4_client_reclaim *crp;
1293	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1294
1295	/* did we already find that this client is stable? */
1296	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1297		return 0;
1298
1299	/* look for it in the reclaim hashtable otherwise */
1300	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1301	if (crp)
1302		goto found;
1303
1304#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1305	if (nn->cld_net->cn_has_legacy) {
1306		int status;
1307		char dname[HEXDIR_LEN];
1308		struct xdr_netobj name;
1309
1310		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1311		if (status)
1312			return -ENOENT;
1313
1314		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1315		if (!name.data) {
1316			dprintk("%s: failed to allocate memory for name.data!\n",
1317				__func__);
1318			return -ENOENT;
1319		}
1320		name.len = HEXDIR_LEN;
1321		crp = nfsd4_find_reclaim_client(name, nn);
1322		kfree(name.data);
1323		if (crp)
1324			goto found;
1325
1326	}
1327#endif
1328	return -ENOENT;
1329found:
1330	crp->cr_clp = clp;
1331	return 0;
1332}
1333
1334static int
1335nfsd4_cld_check_v2(struct nfs4_client *clp)
1336{
1337	struct nfs4_client_reclaim *crp;
1338	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1339	struct cld_net *cn = nn->cld_net;
1340	int status;
1341	struct crypto_shash *tfm = cn->cn_tfm;
1342	struct xdr_netobj cksum;
1343	char *principal = NULL;
1344
1345	/* did we already find that this client is stable? */
1346	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1347		return 0;
1348
1349	/* look for it in the reclaim hashtable otherwise */
1350	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
1351	if (crp)
1352		goto found;
1353
1354#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1355	if (cn->cn_has_legacy) {
1356		struct xdr_netobj name;
1357		char dname[HEXDIR_LEN];
1358
1359		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
1360		if (status)
1361			return -ENOENT;
1362
1363		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
1364		if (!name.data) {
1365			dprintk("%s: failed to allocate memory for name.data\n",
1366					__func__);
1367			return -ENOENT;
1368		}
1369		name.len = HEXDIR_LEN;
1370		crp = nfsd4_find_reclaim_client(name, nn);
1371		kfree(name.data);
1372		if (crp)
1373			goto found;
1374
1375	}
1376#endif
1377	return -ENOENT;
1378found:
1379	if (crp->cr_princhash.len) {
1380		if (clp->cl_cred.cr_raw_principal)
1381			principal = clp->cl_cred.cr_raw_principal;
1382		else if (clp->cl_cred.cr_principal)
1383			principal = clp->cl_cred.cr_principal;
1384		if (principal == NULL)
1385			return -ENOENT;
1386		cksum.len = crypto_shash_digestsize(tfm);
1387		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
1388		if (cksum.data == NULL)
1389			return -ENOENT;
1390		status = crypto_shash_tfm_digest(tfm, principal,
1391						 strlen(principal), cksum.data);
1392		if (status) {
1393			kfree(cksum.data);
1394			return -ENOENT;
1395		}
1396		if (memcmp(crp->cr_princhash.data, cksum.data,
1397				crp->cr_princhash.len)) {
1398			kfree(cksum.data);
1399			return -ENOENT;
1400		}
1401		kfree(cksum.data);
1402	}
1403	crp->cr_clp = clp;
1404	return 0;
1405}
1406
1407static int
1408nfsd4_cld_grace_start(struct nfsd_net *nn)
1409{
1410	int ret;
1411	struct cld_upcall *cup;
1412	struct cld_net *cn = nn->cld_net;
1413
1414	cup = alloc_cld_upcall(nn);
1415	if (!cup) {
1416		ret = -ENOMEM;
1417		goto out_err;
1418	}
1419
1420	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
1421	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1422	if (!ret)
1423		ret = cup->cu_u.cu_msg.cm_status;
1424
1425	free_cld_upcall(cup);
1426out_err:
1427	if (ret)
1428		dprintk("%s: Unable to get clients from userspace: %d\n",
1429			__func__, ret);
1430	return ret;
1431}
1432
1433/* For older nfsdcld's that need cm_gracetime */
1434static void
1435nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
1436{
1437	int ret;
1438	struct cld_upcall *cup;
1439	struct cld_net *cn = nn->cld_net;
1440
1441	cup = alloc_cld_upcall(nn);
1442	if (!cup) {
1443		ret = -ENOMEM;
1444		goto out_err;
1445	}
1446
1447	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1448	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
1449	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1450	if (!ret)
1451		ret = cup->cu_u.cu_msg.cm_status;
1452
1453	free_cld_upcall(cup);
1454out_err:
1455	if (ret)
1456		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1457}
1458
1459/*
1460 * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
1461 * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
1462 */
1463static void
1464nfsd4_cld_grace_done(struct nfsd_net *nn)
1465{
1466	int ret;
1467	struct cld_upcall *cup;
1468	struct cld_net *cn = nn->cld_net;
1469
1470	cup = alloc_cld_upcall(nn);
1471	if (!cup) {
1472		ret = -ENOMEM;
1473		goto out_err;
1474	}
1475
1476	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
1477	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1478	if (!ret)
1479		ret = cup->cu_u.cu_msg.cm_status;
1480
1481	free_cld_upcall(cup);
1482out_err:
1483	nfs4_release_reclaim(nn);
1484	if (ret)
1485		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1486}
1487
1488static int
1489nfs4_cld_state_init(struct net *net)
1490{
1491	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1492	int i;
1493
1494	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
1495						sizeof(struct list_head),
1496						GFP_KERNEL);
1497	if (!nn->reclaim_str_hashtbl)
1498		return -ENOMEM;
1499
1500	for (i = 0; i < CLIENT_HASH_SIZE; i++)
1501		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
1502	nn->reclaim_str_hashtbl_size = 0;
1503	nn->track_reclaim_completes = true;
1504	atomic_set(&nn->nr_reclaim_complete, 0);
1505
1506	return 0;
1507}
1508
1509static void
1510nfs4_cld_state_shutdown(struct net *net)
1511{
1512	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1513
1514	nn->track_reclaim_completes = false;
1515	kfree(nn->reclaim_str_hashtbl);
1516}
1517
1518static bool
1519cld_running(struct nfsd_net *nn)
1520{
1521	struct cld_net *cn = nn->cld_net;
1522	struct rpc_pipe *pipe = cn->cn_pipe;
1523
1524	return pipe->nreaders || pipe->nwriters;
1525}
1526
1527static int
1528nfsd4_cld_get_version(struct nfsd_net *nn)
1529{
1530	int ret = 0;
1531	struct cld_upcall *cup;
1532	struct cld_net *cn = nn->cld_net;
1533	uint8_t version;
1534
1535	cup = alloc_cld_upcall(nn);
1536	if (!cup) {
1537		ret = -ENOMEM;
1538		goto out_err;
1539	}
1540	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
1541	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
1542	if (!ret) {
1543		ret = cup->cu_u.cu_msg.cm_status;
1544		if (ret)
1545			goto out_free;
1546		version = cup->cu_u.cu_msg.cm_u.cm_version;
1547		dprintk("%s: userspace returned version %u\n",
1548				__func__, version);
1549		if (version < 1)
1550			version = 1;
1551		else if (version > CLD_UPCALL_VERSION)
1552			version = CLD_UPCALL_VERSION;
1553
1554		switch (version) {
1555		case 1:
1556			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1557			break;
1558		case 2:
1559			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
1560			break;
1561		default:
1562			break;
1563		}
1564	}
1565out_free:
1566	free_cld_upcall(cup);
1567out_err:
1568	if (ret)
1569		dprintk("%s: Unable to get version from userspace: %d\n",
1570			__func__, ret);
1571	return ret;
1572}
1573
1574static int
1575nfsd4_cld_tracking_init(struct net *net)
1576{
1577	int status;
1578	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1579	bool running;
1580	int retries = 10;
1581	struct crypto_shash *tfm;
1582
1583	status = nfs4_cld_state_init(net);
1584	if (status)
1585		return status;
1586
1587	status = __nfsd4_init_cld_pipe(net);
1588	if (status)
1589		goto err_shutdown;
1590
1591	/*
1592	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
1593	 * queue an upcall unless we know that nfsdcld is running (because we
1594	 * want this to fail fast so that nfsd4_client_tracking_init() can try
1595	 * the next client tracking method).  nfsdcld should already be running
1596	 * before nfsd is started, so the wait here is for nfsdcld to open the
1597	 * pipefs file we just created.
1598	 */
1599	while (!(running = cld_running(nn)) && retries--)
1600		msleep(100);
1601
1602	if (!running) {
1603		status = -ETIMEDOUT;
1604		goto err_remove;
1605	}
1606	tfm = crypto_alloc_shash("sha256", 0, 0);
1607	if (IS_ERR(tfm)) {
1608		status = PTR_ERR(tfm);
1609		goto err_remove;
1610	}
1611	nn->cld_net->cn_tfm = tfm;
1612
1613	status = nfsd4_cld_get_version(nn);
1614	if (status == -EOPNOTSUPP)
1615		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
1616
1617	status = nfsd4_cld_grace_start(nn);
1618	if (status) {
1619		if (status == -EOPNOTSUPP)
1620			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
1621		nfs4_release_reclaim(nn);
1622		goto err_remove;
1623	} else
1624		pr_info("NFSD: Using nfsdcld client tracking operations.\n");
1625	return 0;
1626
1627err_remove:
1628	nfsd4_remove_cld_pipe(net);
1629err_shutdown:
1630	nfs4_cld_state_shutdown(net);
1631	return status;
1632}
1633
1634static void
1635nfsd4_cld_tracking_exit(struct net *net)
1636{
1637	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1638
1639	nfs4_release_reclaim(nn);
1640	nfsd4_remove_cld_pipe(net);
1641	nfs4_cld_state_shutdown(net);
1642}
1643
1644/* For older nfsdcld's */
1645static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
1646	.init		= nfsd4_init_cld_pipe,
1647	.exit		= nfsd4_remove_cld_pipe,
1648	.create		= nfsd4_cld_create,
1649	.remove		= nfsd4_cld_remove,
1650	.check		= nfsd4_cld_check_v0,
1651	.grace_done	= nfsd4_cld_grace_done_v0,
1652	.version	= 1,
1653	.msglen		= sizeof(struct cld_msg),
1654};
1655
1656/* For newer nfsdcld's */
1657static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1658	.init		= nfsd4_cld_tracking_init,
1659	.exit		= nfsd4_cld_tracking_exit,
1660	.create		= nfsd4_cld_create,
1661	.remove		= nfsd4_cld_remove,
1662	.check		= nfsd4_cld_check,
1663	.grace_done	= nfsd4_cld_grace_done,
1664	.version	= 1,
1665	.msglen		= sizeof(struct cld_msg),
1666};
1667
1668/* v2 create/check ops include the principal, if available */
1669static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
1670	.init		= nfsd4_cld_tracking_init,
1671	.exit		= nfsd4_cld_tracking_exit,
1672	.create		= nfsd4_cld_create_v2,
1673	.remove		= nfsd4_cld_remove,
1674	.check		= nfsd4_cld_check_v2,
1675	.grace_done	= nfsd4_cld_grace_done,
1676	.version	= 2,
1677	.msglen		= sizeof(struct cld_msg_v2),
1678};
1679
1680#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
1681/* upcall via usermodehelper */
1682static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1683module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1684			S_IRUGO|S_IWUSR);
1685MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1686
1687static bool cltrack_legacy_disable;
1688module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1689MODULE_PARM_DESC(cltrack_legacy_disable,
1690		"Disable legacy recoverydir conversion. Default: false");
1691
1692#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1693#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1694#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1695#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1696
1697static char *
1698nfsd4_cltrack_legacy_topdir(void)
1699{
1700	int copied;
1701	size_t len;
1702	char *result;
1703
1704	if (cltrack_legacy_disable)
1705		return NULL;
1706
1707	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1708		strlen(nfs4_recoverydir()) + 1;
1709
1710	result = kmalloc(len, GFP_KERNEL);
1711	if (!result)
1712		return result;
1713
1714	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1715				nfs4_recoverydir());
1716	if (copied >= len) {
1717		/* just return nothing if output was truncated */
1718		kfree(result);
1719		return NULL;
1720	}
1721
1722	return result;
1723}
1724
1725static char *
1726nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1727{
1728	int copied;
1729	size_t len;
1730	char *result;
1731
1732	if (cltrack_legacy_disable)
1733		return NULL;
1734
1735	/* +1 is for '/' between "topdir" and "recdir" */
1736	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1737		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1738
1739	result = kmalloc(len, GFP_KERNEL);
1740	if (!result)
1741		return result;
1742
1743	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1744				nfs4_recoverydir());
1745	if (copied > (len - HEXDIR_LEN)) {
1746		/* just return nothing if output will be truncated */
1747		kfree(result);
1748		return NULL;
1749	}
1750
1751	copied = nfs4_make_rec_clidname(result + copied, name);
1752	if (copied) {
1753		kfree(result);
1754		return NULL;
1755	}
1756
1757	return result;
1758}
1759
1760static char *
1761nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1762{
1763	int copied;
1764	size_t len;
1765	char *result;
1766
1767	/* prefix + Y/N character + terminating NULL */
1768	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1769
1770	result = kmalloc(len, GFP_KERNEL);
1771	if (!result)
1772		return result;
1773
1774	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1775				clp->cl_minorversion ? 'Y' : 'N');
1776	if (copied >= len) {
1777		/* just return nothing if output was truncated */
1778		kfree(result);
1779		return NULL;
1780	}
1781
1782	return result;
1783}
1784
1785static char *
1786nfsd4_cltrack_grace_start(time64_t grace_start)
1787{
1788	int copied;
1789	size_t len;
1790	char *result;
1791
1792	/* prefix + max width of int64_t string + terminating NULL */
1793	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1794
1795	result = kmalloc(len, GFP_KERNEL);
1796	if (!result)
1797		return result;
1798
1799	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
1800				grace_start);
1801	if (copied >= len) {
1802		/* just return nothing if output was truncated */
1803		kfree(result);
1804		return NULL;
1805	}
1806
1807	return result;
1808}
1809
1810static int
1811nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1812{
1813	char *envp[3];
1814	char *argv[4];
1815	int ret;
1816
1817	if (unlikely(!cltrack_prog[0])) {
1818		dprintk("%s: cltrack_prog is disabled\n", __func__);
1819		return -EACCES;
1820	}
1821
1822	dprintk("%s: cmd: %s\n", __func__, cmd);
1823	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1824	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1825	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1826
1827	envp[0] = env0;
1828	envp[1] = env1;
1829	envp[2] = NULL;
1830
1831	argv[0] = (char *)cltrack_prog;
1832	argv[1] = cmd;
1833	argv[2] = arg;
1834	argv[3] = NULL;
1835
1836	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1837	/*
1838	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1839	 * error. The admin can re-enable it on the fly by using sysfs
1840	 * once the problem has been fixed.
1841	 */
1842	if (ret == -ENOENT || ret == -EACCES) {
1843		dprintk("NFSD: %s was not found or isn't executable (%d). "
1844			"Setting cltrack_prog to blank string!",
1845			cltrack_prog, ret);
1846		cltrack_prog[0] = '\0';
1847	}
1848	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1849
1850	return ret;
1851}
1852
1853static char *
1854bin_to_hex_dup(const unsigned char *src, int srclen)
1855{
1856	char *buf;
1857
1858	/* +1 for terminating NULL */
1859	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
1860	if (!buf)
1861		return buf;
1862
1863	bin2hex(buf, src, srclen);
1864	return buf;
1865}
1866
1867static int
1868nfsd4_umh_cltrack_init(struct net *net)
1869{
1870	int ret;
1871	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1872	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1873
1874	/* XXX: The usermode helper s not working in container yet. */
1875	if (net != &init_net) {
1876		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1877		kfree(grace_start);
1878		return -EINVAL;
1879	}
1880
1881	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1882	kfree(grace_start);
1883	if (!ret)
1884		pr_info("NFSD: Using UMH upcall client tracking operations.\n");
1885	return ret;
1886}
1887
1888static void
1889nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1890{
1891	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1892			 TASK_UNINTERRUPTIBLE);
1893}
1894
1895static void
1896nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1897{
1898	smp_mb__before_atomic();
1899	clear_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1900	smp_mb__after_atomic();
1901	wake_up_bit(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK);
1902}
1903
1904static void
1905nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1906{
1907	char *hexid, *has_session, *grace_start;
1908	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1909
1910	/*
1911	 * With v4.0 clients, there's little difference in outcome between a
1912	 * create and check operation, and we can end up calling into this
1913	 * function multiple times per client (once for each openowner). So,
1914	 * for v4.0 clients skip upcalling once the client has been recorded
1915	 * on stable storage.
1916	 *
1917	 * For v4.1+ clients, the outcome of the two operations is different,
1918	 * so we must ensure that we upcall for the create operation. v4.1+
1919	 * clients call this on RECLAIM_COMPLETE though, so we should only end
1920	 * up doing a single create upcall per client.
1921	 */
1922	if (clp->cl_minorversion == 0 &&
1923	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1924		return;
1925
1926	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1927	if (!hexid) {
1928		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1929		return;
1930	}
1931
1932	has_session = nfsd4_cltrack_client_has_session(clp);
1933	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1934
1935	nfsd4_cltrack_upcall_lock(clp);
1936	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1937		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1938	nfsd4_cltrack_upcall_unlock(clp);
1939
1940	kfree(has_session);
1941	kfree(grace_start);
1942	kfree(hexid);
1943}
1944
1945static void
1946nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1947{
1948	char *hexid;
1949
1950	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1951		return;
1952
1953	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1954	if (!hexid) {
1955		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1956		return;
1957	}
1958
1959	nfsd4_cltrack_upcall_lock(clp);
1960	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1961	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1962		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1963	nfsd4_cltrack_upcall_unlock(clp);
1964
1965	kfree(hexid);
1966}
1967
1968static int
1969nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1970{
1971	int ret;
1972	char *hexid, *has_session, *legacy;
1973
1974	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1975		return 0;
1976
1977	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1978	if (!hexid) {
1979		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1980		return -ENOMEM;
1981	}
1982
1983	has_session = nfsd4_cltrack_client_has_session(clp);
1984	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1985
1986	nfsd4_cltrack_upcall_lock(clp);
1987	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1988		ret = 0;
1989	} else {
1990		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1991		if (ret == 0)
1992			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1993	}
1994	nfsd4_cltrack_upcall_unlock(clp);
1995	kfree(has_session);
1996	kfree(legacy);
1997	kfree(hexid);
1998
1999	return ret;
2000}
2001
2002static void
2003nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
2004{
2005	char *legacy;
2006	char timestr[22]; /* FIXME: better way to determine max size? */
2007
2008	sprintf(timestr, "%lld", nn->boot_time);
2009	legacy = nfsd4_cltrack_legacy_topdir();
2010	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
2011	kfree(legacy);
2012}
2013
2014static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
2015	.init		= nfsd4_umh_cltrack_init,
2016	.exit		= NULL,
2017	.create		= nfsd4_umh_cltrack_create,
2018	.remove		= nfsd4_umh_cltrack_remove,
2019	.check		= nfsd4_umh_cltrack_check,
2020	.grace_done	= nfsd4_umh_cltrack_grace_done,
2021	.version	= 1,
2022	.msglen		= 0,
2023};
2024
2025static inline int check_for_legacy_methods(int status, struct net *net)
2026{
2027	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2028	struct path path;
2029
2030	/*
2031	 * Next, try the UMH upcall.
2032	 */
2033	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
2034	status = nn->client_tracking_ops->init(net);
2035	if (!status)
2036		return status;
2037
2038	/*
2039	 * Finally, See if the recoverydir exists and is a directory.
2040	 * If it is, then use the legacy ops.
2041	 */
2042	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
2043	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
2044	if (!status) {
2045		status = !d_is_dir(path.dentry);
2046		path_put(&path);
2047		if (status)
2048			return -ENOTDIR;
2049		status = nn->client_tracking_ops->init(net);
2050	}
2051	return status;
2052}
2053#else
2054static inline int check_for_legacy_methods(int status, struct net *net)
2055{
2056	return status;
2057}
2058#endif /* CONFIG_LEGACY_NFSD_CLIENT_TRACKING */
2059
2060int
2061nfsd4_client_tracking_init(struct net *net)
2062{
2063	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2064	int status;
2065
2066	/* just run the init if it the method is already decided */
2067	if (nn->client_tracking_ops)
2068		goto do_init;
2069
2070	/* First, try to use nfsdcld */
2071	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
2072	status = nn->client_tracking_ops->init(net);
2073	if (!status)
2074		return status;
2075	if (status != -ETIMEDOUT) {
2076		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
2077		status = nn->client_tracking_ops->init(net);
2078		if (!status)
2079			return status;
2080	}
2081
2082	status = check_for_legacy_methods(status, net);
2083	if (status)
2084		goto out;
2085do_init:
2086	status = nn->client_tracking_ops->init(net);
2087out:
2088	if (status) {
2089		printk(KERN_WARNING "NFSD: Unable to initialize client "
2090				    "recovery tracking! (%d)\n", status);
2091		nn->client_tracking_ops = NULL;
2092	}
2093	return status;
2094}
2095
2096void
2097nfsd4_client_tracking_exit(struct net *net)
2098{
2099	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2100
2101	if (nn->client_tracking_ops) {
2102		if (nn->client_tracking_ops->exit)
2103			nn->client_tracking_ops->exit(net);
2104		nn->client_tracking_ops = NULL;
2105	}
2106}
2107
2108void
2109nfsd4_client_record_create(struct nfs4_client *clp)
2110{
2111	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2112
2113	if (nn->client_tracking_ops)
2114		nn->client_tracking_ops->create(clp);
2115}
2116
2117void
2118nfsd4_client_record_remove(struct nfs4_client *clp)
2119{
2120	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2121
2122	if (nn->client_tracking_ops)
2123		nn->client_tracking_ops->remove(clp);
2124}
2125
2126int
2127nfsd4_client_record_check(struct nfs4_client *clp)
2128{
2129	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
2130
2131	if (nn->client_tracking_ops)
2132		return nn->client_tracking_ops->check(clp);
2133
2134	return -EOPNOTSUPP;
2135}
2136
2137void
2138nfsd4_record_grace_done(struct nfsd_net *nn)
2139{
2140	if (nn->client_tracking_ops)
2141		nn->client_tracking_ops->grace_done(nn);
2142}
2143
2144static int
2145rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
2146{
2147	struct super_block *sb = ptr;
2148	struct net *net = sb->s_fs_info;
2149	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
2150	struct cld_net *cn = nn->cld_net;
2151	struct dentry *dentry;
2152	int ret = 0;
2153
2154	if (!try_module_get(THIS_MODULE))
2155		return 0;
2156
2157	if (!cn) {
2158		module_put(THIS_MODULE);
2159		return 0;
2160	}
2161
2162	switch (event) {
2163	case RPC_PIPEFS_MOUNT:
2164		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
2165		if (IS_ERR(dentry)) {
2166			ret = PTR_ERR(dentry);
2167			break;
2168		}
2169		cn->cn_pipe->dentry = dentry;
2170		break;
2171	case RPC_PIPEFS_UMOUNT:
2172		if (cn->cn_pipe->dentry)
2173			nfsd4_cld_unregister_sb(cn->cn_pipe);
2174		break;
2175	default:
2176		ret = -ENOTSUPP;
2177		break;
2178	}
2179	module_put(THIS_MODULE);
2180	return ret;
2181}
2182
2183static struct notifier_block nfsd4_cld_block = {
2184	.notifier_call = rpc_pipefs_event,
2185};
2186
2187int
2188register_cld_notifier(void)
2189{
2190	WARN_ON(!nfsd_net_id);
2191	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
2192}
2193
2194void
2195unregister_cld_notifier(void)
2196{
2197	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
2198}