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v3.15
   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 <linux/file.h>
  36#include <linux/slab.h>
  37#include <linux/namei.h>
  38#include <linux/crypto.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 *, time_t);
  62};
  63
  64/* Globals */
  65static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
  66
  67static int
  68nfs4_save_creds(const struct cred **original_creds)
  69{
  70	struct cred *new;
  71
  72	new = prepare_creds();
  73	if (!new)
  74		return -ENOMEM;
  75
  76	new->fsuid = GLOBAL_ROOT_UID;
  77	new->fsgid = GLOBAL_ROOT_GID;
  78	*original_creds = override_creds(new);
  79	put_cred(new);
  80	return 0;
  81}
  82
  83static void
  84nfs4_reset_creds(const struct cred *original)
  85{
  86	revert_creds(original);
  87}
  88
  89static void
  90md5_to_hex(char *out, char *md5)
  91{
  92	int i;
  93
  94	for (i=0; i<16; i++) {
  95		unsigned char c = md5[i];
  96
  97		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
  98		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
  99	}
 100	*out = '\0';
 101}
 102
 103static int
 104nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
 105{
 106	struct xdr_netobj cksum;
 107	struct hash_desc desc;
 108	struct scatterlist sg;
 109	int status;
 110
 111	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
 112			clname->len, clname->data);
 113	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 114	desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
 115	if (IS_ERR(desc.tfm)) {
 116		status = PTR_ERR(desc.tfm);
 117		goto out_no_tfm;
 118	}
 119
 120	cksum.len = crypto_hash_digestsize(desc.tfm);
 121	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
 122	if (cksum.data == NULL) {
 123		status = -ENOMEM;
 124 		goto out;
 125	}
 126
 127	sg_init_one(&sg, clname->data, clname->len);
 
 
 
 
 
 
 
 
 
 128
 129	status = crypto_hash_digest(&desc, &sg, sg.length, cksum.data);
 130	if (status)
 131		goto out;
 132
 133	md5_to_hex(dname, cksum.data);
 134
 135	status = 0;
 136out:
 137	kfree(cksum.data);
 138	crypto_free_hash(desc.tfm);
 139out_no_tfm:
 140	return status;
 141}
 142
 143/*
 144 * If we had an error generating the recdir name for the legacy tracker
 145 * then warn the admin. If the error doesn't appear to be transient,
 146 * then disable recovery tracking.
 147 */
 148static void
 149legacy_recdir_name_error(struct nfs4_client *clp, int error)
 150{
 151	printk(KERN_ERR "NFSD: unable to generate recoverydir "
 152			"name (%d).\n", error);
 153
 154	/*
 155	 * if the algorithm just doesn't exist, then disable the recovery
 156	 * tracker altogether. The crypto libs will generally return this if
 157	 * FIPS is enabled as well.
 158	 */
 159	if (error == -ENOENT) {
 160		printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
 161			"Reboot recovery will not function correctly!\n");
 162		nfsd4_client_tracking_exit(clp->net);
 163	}
 164}
 165
 166static void
 167nfsd4_create_clid_dir(struct nfs4_client *clp)
 168{
 169	const struct cred *original_cred;
 170	char dname[HEXDIR_LEN];
 171	struct dentry *dir, *dentry;
 172	struct nfs4_client_reclaim *crp;
 173	int status;
 174	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 175
 176	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 177		return;
 178	if (!nn->rec_file)
 179		return;
 180
 181	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 182	if (status)
 183		return legacy_recdir_name_error(clp, status);
 184
 185	status = nfs4_save_creds(&original_cred);
 186	if (status < 0)
 187		return;
 188
 189	status = mnt_want_write_file(nn->rec_file);
 190	if (status)
 191		return;
 192
 193	dir = nn->rec_file->f_path.dentry;
 194	/* lock the parent */
 195	mutex_lock(&dir->d_inode->i_mutex);
 196
 197	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
 198	if (IS_ERR(dentry)) {
 199		status = PTR_ERR(dentry);
 200		goto out_unlock;
 201	}
 202	if (dentry->d_inode)
 203		/*
 204		 * In the 4.1 case, where we're called from
 205		 * reclaim_complete(), records from the previous reboot
 206		 * may still be left, so this is OK.
 207		 *
 208		 * In the 4.0 case, we should never get here; but we may
 209		 * as well be forgiving and just succeed silently.
 210		 */
 211		goto out_put;
 212	status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
 213out_put:
 214	dput(dentry);
 215out_unlock:
 216	mutex_unlock(&dir->d_inode->i_mutex);
 217	if (status == 0) {
 218		if (nn->in_grace) {
 219			crp = nfs4_client_to_reclaim(dname, nn);
 220			if (crp)
 221				crp->cr_clp = clp;
 222		}
 223		vfs_fsync(nn->rec_file, 0);
 224	} else {
 225		printk(KERN_ERR "NFSD: failed to write recovery record"
 226				" (err %d); please check that %s exists"
 227				" and is writeable", status,
 228				user_recovery_dirname);
 229	}
 230	mnt_drop_write_file(nn->rec_file);
 
 231	nfs4_reset_creds(original_cred);
 232}
 233
 234typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
 235
 236struct name_list {
 237	char name[HEXDIR_LEN];
 238	struct list_head list;
 239};
 240
 241struct nfs4_dir_ctx {
 242	struct dir_context ctx;
 243	struct list_head names;
 244};
 245
 246static int
 247nfsd4_build_namelist(void *arg, const char *name, int namlen,
 248		loff_t offset, u64 ino, unsigned int d_type)
 249{
 250	struct nfs4_dir_ctx *ctx = arg;
 
 251	struct name_list *entry;
 252
 253	if (namlen != HEXDIR_LEN - 1)
 254		return 0;
 255	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
 256	if (entry == NULL)
 257		return -ENOMEM;
 258	memcpy(entry->name, name, HEXDIR_LEN - 1);
 259	entry->name[HEXDIR_LEN - 1] = '\0';
 260	list_add(&entry->list, &ctx->names);
 261	return 0;
 262}
 263
 264static int
 265nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
 266{
 267	const struct cred *original_cred;
 268	struct dentry *dir = nn->rec_file->f_path.dentry;
 269	struct nfs4_dir_ctx ctx = {
 270		.ctx.actor = nfsd4_build_namelist,
 271		.names = LIST_HEAD_INIT(ctx.names)
 272	};
 
 273	int status;
 274
 275	status = nfs4_save_creds(&original_cred);
 276	if (status < 0)
 277		return status;
 278
 279	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
 280	if (status < 0) {
 281		nfs4_reset_creds(original_cred);
 282		return status;
 283	}
 284
 285	status = iterate_dir(nn->rec_file, &ctx.ctx);
 286	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
 287	while (!list_empty(&ctx.names)) {
 288		struct name_list *entry;
 289		entry = list_entry(ctx.names.next, struct name_list, list);
 290		if (!status) {
 291			struct dentry *dentry;
 292			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
 293			if (IS_ERR(dentry)) {
 294				status = PTR_ERR(dentry);
 295				break;
 296			}
 297			status = f(dir, dentry, nn);
 298			dput(dentry);
 299		}
 300		list_del(&entry->list);
 301		kfree(entry);
 302	}
 303	mutex_unlock(&dir->d_inode->i_mutex);
 304	nfs4_reset_creds(original_cred);
 
 
 
 
 
 
 305	return status;
 306}
 307
 308static int
 309nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
 310{
 311	struct dentry *dir, *dentry;
 312	int status;
 313
 314	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
 315
 316	dir = nn->rec_file->f_path.dentry;
 317	mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
 318	dentry = lookup_one_len(name, dir, namlen);
 319	if (IS_ERR(dentry)) {
 320		status = PTR_ERR(dentry);
 321		goto out_unlock;
 322	}
 323	status = -ENOENT;
 324	if (!dentry->d_inode)
 325		goto out;
 326	status = vfs_rmdir(dir->d_inode, dentry);
 327out:
 328	dput(dentry);
 329out_unlock:
 330	mutex_unlock(&dir->d_inode->i_mutex);
 331	return status;
 332}
 333
 334static void
 335nfsd4_remove_clid_dir(struct nfs4_client *clp)
 336{
 337	const struct cred *original_cred;
 338	struct nfs4_client_reclaim *crp;
 339	char dname[HEXDIR_LEN];
 340	int status;
 341	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 342
 343	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 344		return;
 345
 346	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 347	if (status)
 348		return legacy_recdir_name_error(clp, status);
 349
 350	status = mnt_want_write_file(nn->rec_file);
 351	if (status)
 352		goto out;
 353	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 354
 355	status = nfs4_save_creds(&original_cred);
 356	if (status < 0)
 357		goto out_drop_write;
 358
 359	status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
 360	nfs4_reset_creds(original_cred);
 361	if (status == 0) {
 362		vfs_fsync(nn->rec_file, 0);
 363		if (nn->in_grace) {
 364			/* remove reclaim record */
 365			crp = nfsd4_find_reclaim_client(dname, nn);
 366			if (crp)
 367				nfs4_remove_reclaim_record(crp, nn);
 368		}
 369	}
 370out_drop_write:
 371	mnt_drop_write_file(nn->rec_file);
 372out:
 373	if (status)
 374		printk("NFSD: Failed to remove expired client state directory"
 375				" %.*s\n", HEXDIR_LEN, dname);
 376}
 377
 378static int
 379purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 380{
 381	int status;
 382
 383	if (nfs4_has_reclaimed_state(child->d_name.name, nn))
 384		return 0;
 385
 386	status = vfs_rmdir(parent->d_inode, child);
 387	if (status)
 388		printk("failed to remove client recovery directory %pd\n",
 389				child);
 390	/* Keep trying, success or failure: */
 391	return 0;
 392}
 393
 394static void
 395nfsd4_recdir_purge_old(struct nfsd_net *nn, time_t boot_time)
 396{
 397	int status;
 398
 399	nn->in_grace = false;
 400	if (!nn->rec_file)
 401		return;
 402	status = mnt_want_write_file(nn->rec_file);
 403	if (status)
 404		goto out;
 405	status = nfsd4_list_rec_dir(purge_old, nn);
 406	if (status == 0)
 407		vfs_fsync(nn->rec_file, 0);
 408	mnt_drop_write_file(nn->rec_file);
 409out:
 410	nfs4_release_reclaim(nn);
 411	if (status)
 412		printk("nfsd4: failed to purge old clients from recovery"
 413			" directory %pD\n", nn->rec_file);
 414}
 415
 416static int
 417load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 418{
 419	if (child->d_name.len != HEXDIR_LEN - 1) {
 420		printk("nfsd4: illegal name %pd in recovery directory\n",
 421				child);
 422		/* Keep trying; maybe the others are OK: */
 423		return 0;
 424	}
 425	nfs4_client_to_reclaim(child->d_name.name, nn);
 426	return 0;
 427}
 428
 429static int
 430nfsd4_recdir_load(struct net *net) {
 431	int status;
 432	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
 433
 434	if (!nn->rec_file)
 435		return 0;
 436
 437	status = nfsd4_list_rec_dir(load_recdir, nn);
 438	if (status)
 439		printk("nfsd4: failed loading clients from recovery"
 440			" directory %pD\n", nn->rec_file);
 441	return status;
 442}
 443
 444/*
 445 * Hold reference to the recovery directory.
 446 */
 447
 448static int
 449nfsd4_init_recdir(struct net *net)
 450{
 451	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 452	const struct cred *original_cred;
 453	int status;
 454
 455	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
 456			user_recovery_dirname);
 457
 458	BUG_ON(nn->rec_file);
 459
 460	status = nfs4_save_creds(&original_cred);
 461	if (status < 0) {
 462		printk("NFSD: Unable to change credentials to find recovery"
 463		       " directory: error %d\n",
 464		       status);
 465		return status;
 466	}
 467
 468	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
 469	if (IS_ERR(nn->rec_file)) {
 470		printk("NFSD: unable to find recovery directory %s\n",
 471				user_recovery_dirname);
 472		status = PTR_ERR(nn->rec_file);
 473		nn->rec_file = NULL;
 474	}
 475
 476	nfs4_reset_creds(original_cred);
 477	if (!status)
 478		nn->in_grace = true;
 479	return status;
 480}
 481
 
 
 
 
 
 
 
 
 
 
 482
 483static int
 484nfs4_legacy_state_init(struct net *net)
 485{
 486	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 487	int i;
 488
 489	nn->reclaim_str_hashtbl = kmalloc(sizeof(struct list_head) *
 490					  CLIENT_HASH_SIZE, GFP_KERNEL);
 491	if (!nn->reclaim_str_hashtbl)
 492		return -ENOMEM;
 493
 494	for (i = 0; i < CLIENT_HASH_SIZE; i++)
 495		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
 496	nn->reclaim_str_hashtbl_size = 0;
 497
 498	return 0;
 499}
 500
 501static void
 502nfs4_legacy_state_shutdown(struct net *net)
 503{
 504	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 505
 506	kfree(nn->reclaim_str_hashtbl);
 507}
 508
 509static int
 510nfsd4_load_reboot_recovery_data(struct net *net)
 511{
 512	int status;
 513
 514	status = nfsd4_init_recdir(net);
 515	if (!status)
 516		status = nfsd4_recdir_load(net);
 517	if (status)
 518		printk(KERN_ERR "NFSD: Failure reading reboot recovery data\n");
 
 
 
 
 
 519	return status;
 520}
 521
 522static int
 523nfsd4_legacy_tracking_init(struct net *net)
 524{
 525	int status;
 526
 527	/* XXX: The legacy code won't work in a container */
 528	if (net != &init_net) {
 529		WARN(1, KERN_ERR "NFSD: attempt to initialize legacy client "
 530			"tracking in a container!\n");
 531		return -EINVAL;
 532	}
 533
 534	status = nfs4_legacy_state_init(net);
 535	if (status)
 536		return status;
 537
 538	status = nfsd4_load_reboot_recovery_data(net);
 539	if (status)
 540		goto err;
 541	return 0;
 542
 543err:
 544	nfs4_legacy_state_shutdown(net);
 545	return status;
 546}
 547
 548static void
 549nfsd4_shutdown_recdir(struct nfsd_net *nn)
 550{
 551	if (!nn->rec_file)
 552		return;
 553	fput(nn->rec_file);
 554	nn->rec_file = NULL;
 555}
 556
 557static void
 558nfsd4_legacy_tracking_exit(struct net *net)
 559{
 560	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 561
 562	nfs4_release_reclaim(nn);
 563	nfsd4_shutdown_recdir(nn);
 564	nfs4_legacy_state_shutdown(net);
 565}
 566
 567/*
 568 * Change the NFSv4 recovery directory to recdir.
 569 */
 570int
 571nfs4_reset_recoverydir(char *recdir)
 572{
 573	int status;
 574	struct path path;
 575
 576	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
 577	if (status)
 578		return status;
 579	status = -ENOTDIR;
 580	if (S_ISDIR(path.dentry->d_inode->i_mode)) {
 581		strcpy(user_recovery_dirname, recdir);
 582		status = 0;
 583	}
 584	path_put(&path);
 585	return status;
 586}
 587
 588char *
 589nfs4_recoverydir(void)
 590{
 591	return user_recovery_dirname;
 592}
 593
 594static int
 595nfsd4_check_legacy_client(struct nfs4_client *clp)
 596{
 597	int status;
 598	char dname[HEXDIR_LEN];
 599	struct nfs4_client_reclaim *crp;
 600	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 601
 602	/* did we already find that this client is stable? */
 603	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 604		return 0;
 605
 606	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 607	if (status) {
 608		legacy_recdir_name_error(clp, status);
 609		return status;
 610	}
 611
 612	/* look for it in the reclaim hashtable otherwise */
 613	crp = nfsd4_find_reclaim_client(dname, nn);
 614	if (crp) {
 615		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 616		crp->cr_clp = clp;
 617		return 0;
 618	}
 619
 620	return -ENOENT;
 621}
 622
 623static struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
 624	.init		= nfsd4_legacy_tracking_init,
 625	.exit		= nfsd4_legacy_tracking_exit,
 626	.create		= nfsd4_create_clid_dir,
 627	.remove		= nfsd4_remove_clid_dir,
 628	.check		= nfsd4_check_legacy_client,
 629	.grace_done	= nfsd4_recdir_purge_old,
 630};
 631
 632/* Globals */
 633#define NFSD_PIPE_DIR		"nfsd"
 634#define NFSD_CLD_PIPE		"cld"
 635
 636/* per-net-ns structure for holding cld upcall info */
 637struct cld_net {
 638	struct rpc_pipe		*cn_pipe;
 639	spinlock_t		 cn_lock;
 640	struct list_head	 cn_list;
 641	unsigned int		 cn_xid;
 642};
 643
 644struct cld_upcall {
 645	struct list_head	 cu_list;
 646	struct cld_net		*cu_net;
 647	struct task_struct	*cu_task;
 648	struct cld_msg		 cu_msg;
 649};
 650
 651static int
 652__cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
 653{
 654	int ret;
 655	struct rpc_pipe_msg msg;
 656
 657	memset(&msg, 0, sizeof(msg));
 658	msg.data = cmsg;
 659	msg.len = sizeof(*cmsg);
 660
 661	/*
 662	 * Set task state before we queue the upcall. That prevents
 663	 * wake_up_process in the downcall from racing with schedule.
 664	 */
 665	set_current_state(TASK_UNINTERRUPTIBLE);
 666	ret = rpc_queue_upcall(pipe, &msg);
 667	if (ret < 0) {
 668		set_current_state(TASK_RUNNING);
 669		goto out;
 670	}
 671
 672	schedule();
 673	set_current_state(TASK_RUNNING);
 674
 675	if (msg.errno < 0)
 676		ret = msg.errno;
 677out:
 678	return ret;
 679}
 680
 681static int
 682cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
 683{
 684	int ret;
 685
 686	/*
 687	 * -EAGAIN occurs when pipe is closed and reopened while there are
 688	 *  upcalls queued.
 689	 */
 690	do {
 691		ret = __cld_pipe_upcall(pipe, cmsg);
 692	} while (ret == -EAGAIN);
 693
 694	return ret;
 695}
 696
 697static ssize_t
 698cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 699{
 700	struct cld_upcall *tmp, *cup;
 701	struct cld_msg __user *cmsg = (struct cld_msg __user *)src;
 702	uint32_t xid;
 703	struct nfsd_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info,
 704						nfsd_net_id);
 705	struct cld_net *cn = nn->cld_net;
 706
 707	if (mlen != sizeof(*cmsg)) {
 708		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
 709			sizeof(*cmsg));
 710		return -EINVAL;
 711	}
 712
 713	/* copy just the xid so we can try to find that */
 714	if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) {
 715		dprintk("%s: error when copying xid from userspace", __func__);
 716		return -EFAULT;
 717	}
 718
 719	/* walk the list and find corresponding xid */
 720	cup = NULL;
 721	spin_lock(&cn->cn_lock);
 722	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 723		if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) {
 724			cup = tmp;
 725			list_del_init(&cup->cu_list);
 726			break;
 727		}
 728	}
 729	spin_unlock(&cn->cn_lock);
 730
 731	/* couldn't find upcall? */
 732	if (!cup) {
 733		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
 734		return -EINVAL;
 735	}
 736
 737	if (copy_from_user(&cup->cu_msg, src, mlen) != 0)
 738		return -EFAULT;
 739
 740	wake_up_process(cup->cu_task);
 741	return mlen;
 742}
 743
 744static void
 745cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 746{
 747	struct cld_msg *cmsg = msg->data;
 748	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
 749						 cu_msg);
 750
 751	/* errno >= 0 means we got a downcall */
 752	if (msg->errno >= 0)
 753		return;
 754
 755	wake_up_process(cup->cu_task);
 756}
 757
 758static const struct rpc_pipe_ops cld_upcall_ops = {
 759	.upcall		= rpc_pipe_generic_upcall,
 760	.downcall	= cld_pipe_downcall,
 761	.destroy_msg	= cld_pipe_destroy_msg,
 762};
 763
 764static struct dentry *
 765nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
 766{
 767	struct dentry *dir, *dentry;
 768
 769	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
 770	if (dir == NULL)
 771		return ERR_PTR(-ENOENT);
 772	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
 773	dput(dir);
 774	return dentry;
 775}
 776
 777static void
 778nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
 779{
 780	if (pipe->dentry)
 781		rpc_unlink(pipe->dentry);
 782}
 783
 784static struct dentry *
 785nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
 786{
 787	struct super_block *sb;
 788	struct dentry *dentry;
 789
 790	sb = rpc_get_sb_net(net);
 791	if (!sb)
 792		return NULL;
 793	dentry = nfsd4_cld_register_sb(sb, pipe);
 794	rpc_put_sb_net(net);
 795	return dentry;
 796}
 797
 798static void
 799nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
 800{
 801	struct super_block *sb;
 802
 803	sb = rpc_get_sb_net(net);
 804	if (sb) {
 805		nfsd4_cld_unregister_sb(pipe);
 806		rpc_put_sb_net(net);
 807	}
 808}
 809
 810/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
 811static int
 812nfsd4_init_cld_pipe(struct net *net)
 813{
 814	int ret;
 815	struct dentry *dentry;
 816	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 817	struct cld_net *cn;
 818
 819	if (nn->cld_net)
 820		return 0;
 821
 822	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
 823	if (!cn) {
 824		ret = -ENOMEM;
 825		goto err;
 826	}
 827
 828	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 829	if (IS_ERR(cn->cn_pipe)) {
 830		ret = PTR_ERR(cn->cn_pipe);
 831		goto err;
 832	}
 833	spin_lock_init(&cn->cn_lock);
 834	INIT_LIST_HEAD(&cn->cn_list);
 835
 836	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
 837	if (IS_ERR(dentry)) {
 838		ret = PTR_ERR(dentry);
 839		goto err_destroy_data;
 840	}
 841
 842	cn->cn_pipe->dentry = dentry;
 843	nn->cld_net = cn;
 844	return 0;
 845
 846err_destroy_data:
 847	rpc_destroy_pipe_data(cn->cn_pipe);
 848err:
 849	kfree(cn);
 850	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
 851			ret);
 852	return ret;
 853}
 854
 855static void
 856nfsd4_remove_cld_pipe(struct net *net)
 857{
 858	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 859	struct cld_net *cn = nn->cld_net;
 860
 861	nfsd4_cld_unregister_net(net, cn->cn_pipe);
 862	rpc_destroy_pipe_data(cn->cn_pipe);
 863	kfree(nn->cld_net);
 864	nn->cld_net = NULL;
 865}
 866
 867static struct cld_upcall *
 868alloc_cld_upcall(struct cld_net *cn)
 869{
 870	struct cld_upcall *new, *tmp;
 871
 872	new = kzalloc(sizeof(*new), GFP_KERNEL);
 873	if (!new)
 874		return new;
 875
 876	/* FIXME: hard cap on number in flight? */
 877restart_search:
 878	spin_lock(&cn->cn_lock);
 879	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 880		if (tmp->cu_msg.cm_xid == cn->cn_xid) {
 881			cn->cn_xid++;
 882			spin_unlock(&cn->cn_lock);
 883			goto restart_search;
 884		}
 885	}
 886	new->cu_task = current;
 887	new->cu_msg.cm_vers = CLD_UPCALL_VERSION;
 888	put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid);
 889	new->cu_net = cn;
 890	list_add(&new->cu_list, &cn->cn_list);
 891	spin_unlock(&cn->cn_lock);
 892
 893	dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid);
 894
 895	return new;
 896}
 897
 898static void
 899free_cld_upcall(struct cld_upcall *victim)
 900{
 901	struct cld_net *cn = victim->cu_net;
 902
 903	spin_lock(&cn->cn_lock);
 904	list_del(&victim->cu_list);
 905	spin_unlock(&cn->cn_lock);
 906	kfree(victim);
 907}
 908
 909/* Ask daemon to create a new record */
 910static void
 911nfsd4_cld_create(struct nfs4_client *clp)
 912{
 913	int ret;
 914	struct cld_upcall *cup;
 915	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 916	struct cld_net *cn = nn->cld_net;
 917
 918	/* Don't upcall if it's already stored */
 919	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 920		return;
 921
 922	cup = alloc_cld_upcall(cn);
 923	if (!cup) {
 924		ret = -ENOMEM;
 925		goto out_err;
 926	}
 927
 928	cup->cu_msg.cm_cmd = Cld_Create;
 929	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
 930	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
 931			clp->cl_name.len);
 932
 933	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
 934	if (!ret) {
 935		ret = cup->cu_msg.cm_status;
 936		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 937	}
 938
 939	free_cld_upcall(cup);
 940out_err:
 941	if (ret)
 942		printk(KERN_ERR "NFSD: Unable to create client "
 943				"record on stable storage: %d\n", ret);
 944}
 945
 946/* Ask daemon to create a new record */
 947static void
 948nfsd4_cld_remove(struct nfs4_client *clp)
 949{
 950	int ret;
 951	struct cld_upcall *cup;
 952	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 953	struct cld_net *cn = nn->cld_net;
 954
 955	/* Don't upcall if it's already removed */
 956	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 957		return;
 958
 959	cup = alloc_cld_upcall(cn);
 960	if (!cup) {
 961		ret = -ENOMEM;
 962		goto out_err;
 963	}
 964
 965	cup->cu_msg.cm_cmd = Cld_Remove;
 966	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
 967	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
 968			clp->cl_name.len);
 969
 970	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
 971	if (!ret) {
 972		ret = cup->cu_msg.cm_status;
 973		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 974	}
 975
 976	free_cld_upcall(cup);
 977out_err:
 978	if (ret)
 979		printk(KERN_ERR "NFSD: Unable to remove client "
 980				"record from stable storage: %d\n", ret);
 981}
 982
 983/* Check for presence of a record, and update its timestamp */
 984static int
 985nfsd4_cld_check(struct nfs4_client *clp)
 986{
 987	int ret;
 988	struct cld_upcall *cup;
 989	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 990	struct cld_net *cn = nn->cld_net;
 991
 992	/* Don't upcall if one was already stored during this grace pd */
 993	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 994		return 0;
 995
 996	cup = alloc_cld_upcall(cn);
 997	if (!cup) {
 998		printk(KERN_ERR "NFSD: Unable to check client record on "
 999				"stable storage: %d\n", -ENOMEM);
1000		return -ENOMEM;
1001	}
1002
1003	cup->cu_msg.cm_cmd = Cld_Check;
1004	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1005	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1006			clp->cl_name.len);
1007
1008	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1009	if (!ret) {
1010		ret = cup->cu_msg.cm_status;
1011		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1012	}
1013
1014	free_cld_upcall(cup);
1015	return ret;
1016}
1017
1018static void
1019nfsd4_cld_grace_done(struct nfsd_net *nn, time_t boot_time)
1020{
1021	int ret;
1022	struct cld_upcall *cup;
1023	struct cld_net *cn = nn->cld_net;
1024
1025	cup = alloc_cld_upcall(cn);
1026	if (!cup) {
1027		ret = -ENOMEM;
1028		goto out_err;
1029	}
1030
1031	cup->cu_msg.cm_cmd = Cld_GraceDone;
1032	cup->cu_msg.cm_u.cm_gracetime = (int64_t)boot_time;
1033	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1034	if (!ret)
1035		ret = cup->cu_msg.cm_status;
1036
1037	free_cld_upcall(cup);
1038out_err:
1039	if (ret)
1040		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1041}
1042
1043static struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1044	.init		= nfsd4_init_cld_pipe,
1045	.exit		= nfsd4_remove_cld_pipe,
1046	.create		= nfsd4_cld_create,
1047	.remove		= nfsd4_cld_remove,
1048	.check		= nfsd4_cld_check,
1049	.grace_done	= nfsd4_cld_grace_done,
1050};
1051
1052/* upcall via usermodehelper */
1053static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1054module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1055			S_IRUGO|S_IWUSR);
1056MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1057
1058static bool cltrack_legacy_disable;
1059module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1060MODULE_PARM_DESC(cltrack_legacy_disable,
1061		"Disable legacy recoverydir conversion. Default: false");
1062
1063#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1064#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
 
 
1065
1066static char *
1067nfsd4_cltrack_legacy_topdir(void)
1068{
1069	int copied;
1070	size_t len;
1071	char *result;
1072
1073	if (cltrack_legacy_disable)
1074		return NULL;
1075
1076	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1077		strlen(nfs4_recoverydir()) + 1;
1078
1079	result = kmalloc(len, GFP_KERNEL);
1080	if (!result)
1081		return result;
1082
1083	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1084				nfs4_recoverydir());
1085	if (copied >= len) {
1086		/* just return nothing if output was truncated */
1087		kfree(result);
1088		return NULL;
1089	}
1090
1091	return result;
1092}
1093
1094static char *
1095nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1096{
1097	int copied;
1098	size_t len;
1099	char *result;
1100
1101	if (cltrack_legacy_disable)
1102		return NULL;
1103
1104	/* +1 is for '/' between "topdir" and "recdir" */
1105	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1106		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1107
1108	result = kmalloc(len, GFP_KERNEL);
1109	if (!result)
1110		return result;
1111
1112	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1113				nfs4_recoverydir());
1114	if (copied > (len - HEXDIR_LEN)) {
1115		/* just return nothing if output will be truncated */
1116		kfree(result);
1117		return NULL;
1118	}
1119
1120	copied = nfs4_make_rec_clidname(result + copied, name);
1121	if (copied) {
1122		kfree(result);
1123		return NULL;
1124	}
1125
1126	return result;
1127}
1128
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1129static int
1130nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *legacy)
1131{
1132	char *envp[2];
1133	char *argv[4];
1134	int ret;
1135
1136	if (unlikely(!cltrack_prog[0])) {
1137		dprintk("%s: cltrack_prog is disabled\n", __func__);
1138		return -EACCES;
1139	}
1140
1141	dprintk("%s: cmd: %s\n", __func__, cmd);
1142	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1143	dprintk("%s: legacy: %s\n", __func__, legacy ? legacy : "(null)");
 
1144
1145	envp[0] = legacy;
1146	envp[1] = NULL;
 
1147
1148	argv[0] = (char *)cltrack_prog;
1149	argv[1] = cmd;
1150	argv[2] = arg;
1151	argv[3] = NULL;
1152
1153	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1154	/*
1155	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1156	 * error. The admin can re-enable it on the fly by using sysfs
1157	 * once the problem has been fixed.
1158	 */
1159	if (ret == -ENOENT || ret == -EACCES) {
1160		dprintk("NFSD: %s was not found or isn't executable (%d). "
1161			"Setting cltrack_prog to blank string!",
1162			cltrack_prog, ret);
1163		cltrack_prog[0] = '\0';
1164	}
1165	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1166
1167	return ret;
1168}
1169
1170static char *
1171bin_to_hex_dup(const unsigned char *src, int srclen)
1172{
1173	int i;
1174	char *buf, *hex;
1175
1176	/* +1 for terminating NULL */
1177	buf = kmalloc((srclen * 2) + 1, GFP_KERNEL);
1178	if (!buf)
1179		return buf;
1180
1181	hex = buf;
1182	for (i = 0; i < srclen; i++) {
1183		sprintf(hex, "%2.2x", *src++);
1184		hex += 2;
1185	}
1186	return buf;
1187}
1188
1189static int
1190nfsd4_umh_cltrack_init(struct net __attribute__((unused)) *net)
1191{
 
 
 
 
1192	/* XXX: The usermode helper s not working in container yet. */
1193	if (net != &init_net) {
1194		WARN(1, KERN_ERR "NFSD: attempt to initialize umh client "
1195			"tracking in a container!\n");
1196		return -EINVAL;
1197	}
1198	return nfsd4_umh_cltrack_upcall("init", NULL, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1199}
1200
1201static void
1202nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1203{
1204	char *hexid;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1205
1206	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1207	if (!hexid) {
1208		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1209		return;
1210	}
1211	nfsd4_umh_cltrack_upcall("create", hexid, NULL);
 
 
 
 
 
 
 
 
 
 
1212	kfree(hexid);
1213}
1214
1215static void
1216nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1217{
1218	char *hexid;
1219
 
 
 
1220	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1221	if (!hexid) {
1222		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1223		return;
1224	}
1225	nfsd4_umh_cltrack_upcall("remove", hexid, NULL);
 
 
 
 
 
 
1226	kfree(hexid);
1227}
1228
1229static int
1230nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1231{
1232	int ret;
1233	char *hexid, *legacy;
 
 
 
1234
1235	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1236	if (!hexid) {
1237		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1238		return -ENOMEM;
1239	}
 
 
1240	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1241	ret = nfsd4_umh_cltrack_upcall("check", hexid, legacy);
 
 
 
 
 
 
 
 
 
 
1242	kfree(legacy);
1243	kfree(hexid);
 
1244	return ret;
1245}
1246
1247static void
1248nfsd4_umh_cltrack_grace_done(struct nfsd_net __attribute__((unused)) *nn,
1249				time_t boot_time)
1250{
1251	char *legacy;
1252	char timestr[22]; /* FIXME: better way to determine max size? */
1253
1254	sprintf(timestr, "%ld", boot_time);
1255	legacy = nfsd4_cltrack_legacy_topdir();
1256	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy);
1257	kfree(legacy);
1258}
1259
1260static struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
1261	.init		= nfsd4_umh_cltrack_init,
1262	.exit		= NULL,
1263	.create		= nfsd4_umh_cltrack_create,
1264	.remove		= nfsd4_umh_cltrack_remove,
1265	.check		= nfsd4_umh_cltrack_check,
1266	.grace_done	= nfsd4_umh_cltrack_grace_done,
1267};
1268
1269int
1270nfsd4_client_tracking_init(struct net *net)
1271{
1272	int status;
1273	struct path path;
1274	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1275
1276	/* just run the init if it the method is already decided */
1277	if (nn->client_tracking_ops)
1278		goto do_init;
1279
1280	/*
1281	 * First, try a UMH upcall. It should succeed or fail quickly, so
1282	 * there's little harm in trying that first.
1283	 */
1284	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
1285	status = nn->client_tracking_ops->init(net);
1286	if (!status)
1287		return status;
1288
1289	/*
1290	 * See if the recoverydir exists and is a directory. If it is,
1291	 * then use the legacy ops.
1292	 */
1293	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
1294	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
1295	if (!status) {
1296		status = S_ISDIR(path.dentry->d_inode->i_mode);
1297		path_put(&path);
1298		if (status)
1299			goto do_init;
1300	}
1301
1302	/* Finally, try to use nfsdcld */
1303	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1304	printk(KERN_WARNING "NFSD: the nfsdcld client tracking upcall will be "
1305			"removed in 3.10. Please transition to using "
1306			"nfsdcltrack.\n");
1307do_init:
1308	status = nn->client_tracking_ops->init(net);
1309	if (status) {
1310		printk(KERN_WARNING "NFSD: Unable to initialize client "
1311				    "recovery tracking! (%d)\n", status);
1312		nn->client_tracking_ops = NULL;
1313	}
1314	return status;
1315}
1316
1317void
1318nfsd4_client_tracking_exit(struct net *net)
1319{
1320	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1321
1322	if (nn->client_tracking_ops) {
1323		if (nn->client_tracking_ops->exit)
1324			nn->client_tracking_ops->exit(net);
1325		nn->client_tracking_ops = NULL;
1326	}
1327}
1328
1329void
1330nfsd4_client_record_create(struct nfs4_client *clp)
1331{
1332	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1333
1334	if (nn->client_tracking_ops)
1335		nn->client_tracking_ops->create(clp);
1336}
1337
1338void
1339nfsd4_client_record_remove(struct nfs4_client *clp)
1340{
1341	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1342
1343	if (nn->client_tracking_ops)
1344		nn->client_tracking_ops->remove(clp);
1345}
1346
1347int
1348nfsd4_client_record_check(struct nfs4_client *clp)
1349{
1350	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1351
1352	if (nn->client_tracking_ops)
1353		return nn->client_tracking_ops->check(clp);
1354
1355	return -EOPNOTSUPP;
1356}
1357
1358void
1359nfsd4_record_grace_done(struct nfsd_net *nn, time_t boot_time)
1360{
1361	if (nn->client_tracking_ops)
1362		nn->client_tracking_ops->grace_done(nn, boot_time);
1363}
1364
1365static int
1366rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
1367{
1368	struct super_block *sb = ptr;
1369	struct net *net = sb->s_fs_info;
1370	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1371	struct cld_net *cn = nn->cld_net;
1372	struct dentry *dentry;
1373	int ret = 0;
1374
1375	if (!try_module_get(THIS_MODULE))
1376		return 0;
1377
1378	if (!cn) {
1379		module_put(THIS_MODULE);
1380		return 0;
1381	}
1382
1383	switch (event) {
1384	case RPC_PIPEFS_MOUNT:
1385		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
1386		if (IS_ERR(dentry)) {
1387			ret = PTR_ERR(dentry);
1388			break;
1389		}
1390		cn->cn_pipe->dentry = dentry;
1391		break;
1392	case RPC_PIPEFS_UMOUNT:
1393		if (cn->cn_pipe->dentry)
1394			nfsd4_cld_unregister_sb(cn->cn_pipe);
1395		break;
1396	default:
1397		ret = -ENOTSUPP;
1398		break;
1399	}
1400	module_put(THIS_MODULE);
1401	return ret;
1402}
1403
1404static struct notifier_block nfsd4_cld_block = {
1405	.notifier_call = rpc_pipefs_event,
1406};
1407
1408int
1409register_cld_notifier(void)
1410{
1411	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
1412}
1413
1414void
1415unregister_cld_notifier(void)
1416{
1417	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
1418}
v4.17
   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};
  63
  64/* Globals */
  65static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
  66
  67static int
  68nfs4_save_creds(const struct cred **original_creds)
  69{
  70	struct cred *new;
  71
  72	new = prepare_creds();
  73	if (!new)
  74		return -ENOMEM;
  75
  76	new->fsuid = GLOBAL_ROOT_UID;
  77	new->fsgid = GLOBAL_ROOT_GID;
  78	*original_creds = override_creds(new);
  79	put_cred(new);
  80	return 0;
  81}
  82
  83static void
  84nfs4_reset_creds(const struct cred *original)
  85{
  86	revert_creds(original);
  87}
  88
  89static void
  90md5_to_hex(char *out, char *md5)
  91{
  92	int i;
  93
  94	for (i=0; i<16; i++) {
  95		unsigned char c = md5[i];
  96
  97		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
  98		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
  99	}
 100	*out = '\0';
 101}
 102
 103static int
 104nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
 105{
 106	struct xdr_netobj cksum;
 107	struct crypto_shash *tfm;
 
 108	int status;
 109
 110	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
 111			clname->len, clname->data);
 112	tfm = crypto_alloc_shash("md5", 0, 0);
 113	if (IS_ERR(tfm)) {
 114		status = PTR_ERR(tfm);
 
 115		goto out_no_tfm;
 116	}
 117
 118	cksum.len = crypto_shash_digestsize(tfm);
 119	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
 120	if (cksum.data == NULL) {
 121		status = -ENOMEM;
 122 		goto out;
 123	}
 124
 125	{
 126		SHASH_DESC_ON_STACK(desc, tfm);
 127
 128		desc->tfm = tfm;
 129		desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 130
 131		status = crypto_shash_digest(desc, clname->data, clname->len,
 132					     cksum.data);
 133		shash_desc_zero(desc);
 134	}
 135
 
 136	if (status)
 137		goto out;
 138
 139	md5_to_hex(dname, cksum.data);
 140
 141	status = 0;
 142out:
 143	kfree(cksum.data);
 144	crypto_free_shash(tfm);
 145out_no_tfm:
 146	return status;
 147}
 148
 149/*
 150 * If we had an error generating the recdir name for the legacy tracker
 151 * then warn the admin. If the error doesn't appear to be transient,
 152 * then disable recovery tracking.
 153 */
 154static void
 155legacy_recdir_name_error(struct nfs4_client *clp, int error)
 156{
 157	printk(KERN_ERR "NFSD: unable to generate recoverydir "
 158			"name (%d).\n", error);
 159
 160	/*
 161	 * if the algorithm just doesn't exist, then disable the recovery
 162	 * tracker altogether. The crypto libs will generally return this if
 163	 * FIPS is enabled as well.
 164	 */
 165	if (error == -ENOENT) {
 166		printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
 167			"Reboot recovery will not function correctly!\n");
 168		nfsd4_client_tracking_exit(clp->net);
 169	}
 170}
 171
 172static void
 173nfsd4_create_clid_dir(struct nfs4_client *clp)
 174{
 175	const struct cred *original_cred;
 176	char dname[HEXDIR_LEN];
 177	struct dentry *dir, *dentry;
 178	struct nfs4_client_reclaim *crp;
 179	int status;
 180	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 181
 182	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 183		return;
 184	if (!nn->rec_file)
 185		return;
 186
 187	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 188	if (status)
 189		return legacy_recdir_name_error(clp, status);
 190
 191	status = nfs4_save_creds(&original_cred);
 192	if (status < 0)
 193		return;
 194
 195	status = mnt_want_write_file(nn->rec_file);
 196	if (status)
 197		goto out_creds;
 198
 199	dir = nn->rec_file->f_path.dentry;
 200	/* lock the parent */
 201	inode_lock(d_inode(dir));
 202
 203	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
 204	if (IS_ERR(dentry)) {
 205		status = PTR_ERR(dentry);
 206		goto out_unlock;
 207	}
 208	if (d_really_is_positive(dentry))
 209		/*
 210		 * In the 4.1 case, where we're called from
 211		 * reclaim_complete(), records from the previous reboot
 212		 * may still be left, so this is OK.
 213		 *
 214		 * In the 4.0 case, we should never get here; but we may
 215		 * as well be forgiving and just succeed silently.
 216		 */
 217		goto out_put;
 218	status = vfs_mkdir(d_inode(dir), dentry, S_IRWXU);
 219out_put:
 220	dput(dentry);
 221out_unlock:
 222	inode_unlock(d_inode(dir));
 223	if (status == 0) {
 224		if (nn->in_grace) {
 225			crp = nfs4_client_to_reclaim(dname, nn);
 226			if (crp)
 227				crp->cr_clp = clp;
 228		}
 229		vfs_fsync(nn->rec_file, 0);
 230	} else {
 231		printk(KERN_ERR "NFSD: failed to write recovery record"
 232				" (err %d); please check that %s exists"
 233				" and is writeable", status,
 234				user_recovery_dirname);
 235	}
 236	mnt_drop_write_file(nn->rec_file);
 237out_creds:
 238	nfs4_reset_creds(original_cred);
 239}
 240
 241typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
 242
 243struct name_list {
 244	char name[HEXDIR_LEN];
 245	struct list_head list;
 246};
 247
 248struct nfs4_dir_ctx {
 249	struct dir_context ctx;
 250	struct list_head names;
 251};
 252
 253static int
 254nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
 255		loff_t offset, u64 ino, unsigned int d_type)
 256{
 257	struct nfs4_dir_ctx *ctx =
 258		container_of(__ctx, struct nfs4_dir_ctx, ctx);
 259	struct name_list *entry;
 260
 261	if (namlen != HEXDIR_LEN - 1)
 262		return 0;
 263	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
 264	if (entry == NULL)
 265		return -ENOMEM;
 266	memcpy(entry->name, name, HEXDIR_LEN - 1);
 267	entry->name[HEXDIR_LEN - 1] = '\0';
 268	list_add(&entry->list, &ctx->names);
 269	return 0;
 270}
 271
 272static int
 273nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
 274{
 275	const struct cred *original_cred;
 276	struct dentry *dir = nn->rec_file->f_path.dentry;
 277	struct nfs4_dir_ctx ctx = {
 278		.ctx.actor = nfsd4_build_namelist,
 279		.names = LIST_HEAD_INIT(ctx.names)
 280	};
 281	struct name_list *entry, *tmp;
 282	int status;
 283
 284	status = nfs4_save_creds(&original_cred);
 285	if (status < 0)
 286		return status;
 287
 288	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
 289	if (status < 0) {
 290		nfs4_reset_creds(original_cred);
 291		return status;
 292	}
 293
 294	status = iterate_dir(nn->rec_file, &ctx.ctx);
 295	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 296
 297	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 
 298		if (!status) {
 299			struct dentry *dentry;
 300			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
 301			if (IS_ERR(dentry)) {
 302				status = PTR_ERR(dentry);
 303				break;
 304			}
 305			status = f(dir, dentry, nn);
 306			dput(dentry);
 307		}
 308		list_del(&entry->list);
 309		kfree(entry);
 310	}
 311	inode_unlock(d_inode(dir));
 312	nfs4_reset_creds(original_cred);
 313
 314	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
 315		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
 316		list_del(&entry->list);
 317		kfree(entry);
 318	}
 319	return status;
 320}
 321
 322static int
 323nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
 324{
 325	struct dentry *dir, *dentry;
 326	int status;
 327
 328	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
 329
 330	dir = nn->rec_file->f_path.dentry;
 331	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 332	dentry = lookup_one_len(name, dir, namlen);
 333	if (IS_ERR(dentry)) {
 334		status = PTR_ERR(dentry);
 335		goto out_unlock;
 336	}
 337	status = -ENOENT;
 338	if (d_really_is_negative(dentry))
 339		goto out;
 340	status = vfs_rmdir(d_inode(dir), dentry);
 341out:
 342	dput(dentry);
 343out_unlock:
 344	inode_unlock(d_inode(dir));
 345	return status;
 346}
 347
 348static void
 349nfsd4_remove_clid_dir(struct nfs4_client *clp)
 350{
 351	const struct cred *original_cred;
 352	struct nfs4_client_reclaim *crp;
 353	char dname[HEXDIR_LEN];
 354	int status;
 355	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 356
 357	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 358		return;
 359
 360	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 361	if (status)
 362		return legacy_recdir_name_error(clp, status);
 363
 364	status = mnt_want_write_file(nn->rec_file);
 365	if (status)
 366		goto out;
 367	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 368
 369	status = nfs4_save_creds(&original_cred);
 370	if (status < 0)
 371		goto out_drop_write;
 372
 373	status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
 374	nfs4_reset_creds(original_cred);
 375	if (status == 0) {
 376		vfs_fsync(nn->rec_file, 0);
 377		if (nn->in_grace) {
 378			/* remove reclaim record */
 379			crp = nfsd4_find_reclaim_client(dname, nn);
 380			if (crp)
 381				nfs4_remove_reclaim_record(crp, nn);
 382		}
 383	}
 384out_drop_write:
 385	mnt_drop_write_file(nn->rec_file);
 386out:
 387	if (status)
 388		printk("NFSD: Failed to remove expired client state directory"
 389				" %.*s\n", HEXDIR_LEN, dname);
 390}
 391
 392static int
 393purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 394{
 395	int status;
 396
 397	if (nfs4_has_reclaimed_state(child->d_name.name, nn))
 398		return 0;
 399
 400	status = vfs_rmdir(d_inode(parent), child);
 401	if (status)
 402		printk("failed to remove client recovery directory %pd\n",
 403				child);
 404	/* Keep trying, success or failure: */
 405	return 0;
 406}
 407
 408static void
 409nfsd4_recdir_purge_old(struct nfsd_net *nn)
 410{
 411	int status;
 412
 413	nn->in_grace = false;
 414	if (!nn->rec_file)
 415		return;
 416	status = mnt_want_write_file(nn->rec_file);
 417	if (status)
 418		goto out;
 419	status = nfsd4_list_rec_dir(purge_old, nn);
 420	if (status == 0)
 421		vfs_fsync(nn->rec_file, 0);
 422	mnt_drop_write_file(nn->rec_file);
 423out:
 424	nfs4_release_reclaim(nn);
 425	if (status)
 426		printk("nfsd4: failed to purge old clients from recovery"
 427			" directory %pD\n", nn->rec_file);
 428}
 429
 430static int
 431load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
 432{
 433	if (child->d_name.len != HEXDIR_LEN - 1) {
 434		printk("nfsd4: illegal name %pd in recovery directory\n",
 435				child);
 436		/* Keep trying; maybe the others are OK: */
 437		return 0;
 438	}
 439	nfs4_client_to_reclaim(child->d_name.name, nn);
 440	return 0;
 441}
 442
 443static int
 444nfsd4_recdir_load(struct net *net) {
 445	int status;
 446	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
 447
 448	if (!nn->rec_file)
 449		return 0;
 450
 451	status = nfsd4_list_rec_dir(load_recdir, nn);
 452	if (status)
 453		printk("nfsd4: failed loading clients from recovery"
 454			" directory %pD\n", nn->rec_file);
 455	return status;
 456}
 457
 458/*
 459 * Hold reference to the recovery directory.
 460 */
 461
 462static int
 463nfsd4_init_recdir(struct net *net)
 464{
 465	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 466	const struct cred *original_cred;
 467	int status;
 468
 469	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
 470			user_recovery_dirname);
 471
 472	BUG_ON(nn->rec_file);
 473
 474	status = nfs4_save_creds(&original_cred);
 475	if (status < 0) {
 476		printk("NFSD: Unable to change credentials to find recovery"
 477		       " directory: error %d\n",
 478		       status);
 479		return status;
 480	}
 481
 482	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
 483	if (IS_ERR(nn->rec_file)) {
 484		printk("NFSD: unable to find recovery directory %s\n",
 485				user_recovery_dirname);
 486		status = PTR_ERR(nn->rec_file);
 487		nn->rec_file = NULL;
 488	}
 489
 490	nfs4_reset_creds(original_cred);
 491	if (!status)
 492		nn->in_grace = true;
 493	return status;
 494}
 495
 496static void
 497nfsd4_shutdown_recdir(struct net *net)
 498{
 499	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 500
 501	if (!nn->rec_file)
 502		return;
 503	fput(nn->rec_file);
 504	nn->rec_file = NULL;
 505}
 506
 507static int
 508nfs4_legacy_state_init(struct net *net)
 509{
 510	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 511	int i;
 512
 513	nn->reclaim_str_hashtbl = kmalloc(sizeof(struct list_head) *
 514					  CLIENT_HASH_SIZE, GFP_KERNEL);
 515	if (!nn->reclaim_str_hashtbl)
 516		return -ENOMEM;
 517
 518	for (i = 0; i < CLIENT_HASH_SIZE; i++)
 519		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
 520	nn->reclaim_str_hashtbl_size = 0;
 521
 522	return 0;
 523}
 524
 525static void
 526nfs4_legacy_state_shutdown(struct net *net)
 527{
 528	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 529
 530	kfree(nn->reclaim_str_hashtbl);
 531}
 532
 533static int
 534nfsd4_load_reboot_recovery_data(struct net *net)
 535{
 536	int status;
 537
 538	status = nfsd4_init_recdir(net);
 
 
 539	if (status)
 540		return status;
 541
 542	status = nfsd4_recdir_load(net);
 543	if (status)
 544		nfsd4_shutdown_recdir(net);
 545
 546	return status;
 547}
 548
 549static int
 550nfsd4_legacy_tracking_init(struct net *net)
 551{
 552	int status;
 553
 554	/* XXX: The legacy code won't work in a container */
 555	if (net != &init_net) {
 556		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
 
 557		return -EINVAL;
 558	}
 559
 560	status = nfs4_legacy_state_init(net);
 561	if (status)
 562		return status;
 563
 564	status = nfsd4_load_reboot_recovery_data(net);
 565	if (status)
 566		goto err;
 567	return 0;
 568
 569err:
 570	nfs4_legacy_state_shutdown(net);
 571	return status;
 572}
 573
 574static void
 
 
 
 
 
 
 
 
 
 575nfsd4_legacy_tracking_exit(struct net *net)
 576{
 577	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 578
 579	nfs4_release_reclaim(nn);
 580	nfsd4_shutdown_recdir(net);
 581	nfs4_legacy_state_shutdown(net);
 582}
 583
 584/*
 585 * Change the NFSv4 recovery directory to recdir.
 586 */
 587int
 588nfs4_reset_recoverydir(char *recdir)
 589{
 590	int status;
 591	struct path path;
 592
 593	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
 594	if (status)
 595		return status;
 596	status = -ENOTDIR;
 597	if (d_is_dir(path.dentry)) {
 598		strcpy(user_recovery_dirname, recdir);
 599		status = 0;
 600	}
 601	path_put(&path);
 602	return status;
 603}
 604
 605char *
 606nfs4_recoverydir(void)
 607{
 608	return user_recovery_dirname;
 609}
 610
 611static int
 612nfsd4_check_legacy_client(struct nfs4_client *clp)
 613{
 614	int status;
 615	char dname[HEXDIR_LEN];
 616	struct nfs4_client_reclaim *crp;
 617	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 618
 619	/* did we already find that this client is stable? */
 620	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 621		return 0;
 622
 623	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
 624	if (status) {
 625		legacy_recdir_name_error(clp, status);
 626		return status;
 627	}
 628
 629	/* look for it in the reclaim hashtable otherwise */
 630	crp = nfsd4_find_reclaim_client(dname, nn);
 631	if (crp) {
 632		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 633		crp->cr_clp = clp;
 634		return 0;
 635	}
 636
 637	return -ENOENT;
 638}
 639
 640static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
 641	.init		= nfsd4_legacy_tracking_init,
 642	.exit		= nfsd4_legacy_tracking_exit,
 643	.create		= nfsd4_create_clid_dir,
 644	.remove		= nfsd4_remove_clid_dir,
 645	.check		= nfsd4_check_legacy_client,
 646	.grace_done	= nfsd4_recdir_purge_old,
 647};
 648
 649/* Globals */
 650#define NFSD_PIPE_DIR		"nfsd"
 651#define NFSD_CLD_PIPE		"cld"
 652
 653/* per-net-ns structure for holding cld upcall info */
 654struct cld_net {
 655	struct rpc_pipe		*cn_pipe;
 656	spinlock_t		 cn_lock;
 657	struct list_head	 cn_list;
 658	unsigned int		 cn_xid;
 659};
 660
 661struct cld_upcall {
 662	struct list_head	 cu_list;
 663	struct cld_net		*cu_net;
 664	struct task_struct	*cu_task;
 665	struct cld_msg		 cu_msg;
 666};
 667
 668static int
 669__cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
 670{
 671	int ret;
 672	struct rpc_pipe_msg msg;
 673
 674	memset(&msg, 0, sizeof(msg));
 675	msg.data = cmsg;
 676	msg.len = sizeof(*cmsg);
 677
 678	/*
 679	 * Set task state before we queue the upcall. That prevents
 680	 * wake_up_process in the downcall from racing with schedule.
 681	 */
 682	set_current_state(TASK_UNINTERRUPTIBLE);
 683	ret = rpc_queue_upcall(pipe, &msg);
 684	if (ret < 0) {
 685		set_current_state(TASK_RUNNING);
 686		goto out;
 687	}
 688
 689	schedule();
 
 690
 691	if (msg.errno < 0)
 692		ret = msg.errno;
 693out:
 694	return ret;
 695}
 696
 697static int
 698cld_pipe_upcall(struct rpc_pipe *pipe, struct cld_msg *cmsg)
 699{
 700	int ret;
 701
 702	/*
 703	 * -EAGAIN occurs when pipe is closed and reopened while there are
 704	 *  upcalls queued.
 705	 */
 706	do {
 707		ret = __cld_pipe_upcall(pipe, cmsg);
 708	} while (ret == -EAGAIN);
 709
 710	return ret;
 711}
 712
 713static ssize_t
 714cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 715{
 716	struct cld_upcall *tmp, *cup;
 717	struct cld_msg __user *cmsg = (struct cld_msg __user *)src;
 718	uint32_t xid;
 719	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
 720						nfsd_net_id);
 721	struct cld_net *cn = nn->cld_net;
 722
 723	if (mlen != sizeof(*cmsg)) {
 724		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
 725			sizeof(*cmsg));
 726		return -EINVAL;
 727	}
 728
 729	/* copy just the xid so we can try to find that */
 730	if (copy_from_user(&xid, &cmsg->cm_xid, sizeof(xid)) != 0) {
 731		dprintk("%s: error when copying xid from userspace", __func__);
 732		return -EFAULT;
 733	}
 734
 735	/* walk the list and find corresponding xid */
 736	cup = NULL;
 737	spin_lock(&cn->cn_lock);
 738	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 739		if (get_unaligned(&tmp->cu_msg.cm_xid) == xid) {
 740			cup = tmp;
 741			list_del_init(&cup->cu_list);
 742			break;
 743		}
 744	}
 745	spin_unlock(&cn->cn_lock);
 746
 747	/* couldn't find upcall? */
 748	if (!cup) {
 749		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
 750		return -EINVAL;
 751	}
 752
 753	if (copy_from_user(&cup->cu_msg, src, mlen) != 0)
 754		return -EFAULT;
 755
 756	wake_up_process(cup->cu_task);
 757	return mlen;
 758}
 759
 760static void
 761cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 762{
 763	struct cld_msg *cmsg = msg->data;
 764	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
 765						 cu_msg);
 766
 767	/* errno >= 0 means we got a downcall */
 768	if (msg->errno >= 0)
 769		return;
 770
 771	wake_up_process(cup->cu_task);
 772}
 773
 774static const struct rpc_pipe_ops cld_upcall_ops = {
 775	.upcall		= rpc_pipe_generic_upcall,
 776	.downcall	= cld_pipe_downcall,
 777	.destroy_msg	= cld_pipe_destroy_msg,
 778};
 779
 780static struct dentry *
 781nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
 782{
 783	struct dentry *dir, *dentry;
 784
 785	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
 786	if (dir == NULL)
 787		return ERR_PTR(-ENOENT);
 788	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
 789	dput(dir);
 790	return dentry;
 791}
 792
 793static void
 794nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
 795{
 796	if (pipe->dentry)
 797		rpc_unlink(pipe->dentry);
 798}
 799
 800static struct dentry *
 801nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
 802{
 803	struct super_block *sb;
 804	struct dentry *dentry;
 805
 806	sb = rpc_get_sb_net(net);
 807	if (!sb)
 808		return NULL;
 809	dentry = nfsd4_cld_register_sb(sb, pipe);
 810	rpc_put_sb_net(net);
 811	return dentry;
 812}
 813
 814static void
 815nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
 816{
 817	struct super_block *sb;
 818
 819	sb = rpc_get_sb_net(net);
 820	if (sb) {
 821		nfsd4_cld_unregister_sb(pipe);
 822		rpc_put_sb_net(net);
 823	}
 824}
 825
 826/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
 827static int
 828nfsd4_init_cld_pipe(struct net *net)
 829{
 830	int ret;
 831	struct dentry *dentry;
 832	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 833	struct cld_net *cn;
 834
 835	if (nn->cld_net)
 836		return 0;
 837
 838	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
 839	if (!cn) {
 840		ret = -ENOMEM;
 841		goto err;
 842	}
 843
 844	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 845	if (IS_ERR(cn->cn_pipe)) {
 846		ret = PTR_ERR(cn->cn_pipe);
 847		goto err;
 848	}
 849	spin_lock_init(&cn->cn_lock);
 850	INIT_LIST_HEAD(&cn->cn_list);
 851
 852	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
 853	if (IS_ERR(dentry)) {
 854		ret = PTR_ERR(dentry);
 855		goto err_destroy_data;
 856	}
 857
 858	cn->cn_pipe->dentry = dentry;
 859	nn->cld_net = cn;
 860	return 0;
 861
 862err_destroy_data:
 863	rpc_destroy_pipe_data(cn->cn_pipe);
 864err:
 865	kfree(cn);
 866	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
 867			ret);
 868	return ret;
 869}
 870
 871static void
 872nfsd4_remove_cld_pipe(struct net *net)
 873{
 874	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 875	struct cld_net *cn = nn->cld_net;
 876
 877	nfsd4_cld_unregister_net(net, cn->cn_pipe);
 878	rpc_destroy_pipe_data(cn->cn_pipe);
 879	kfree(nn->cld_net);
 880	nn->cld_net = NULL;
 881}
 882
 883static struct cld_upcall *
 884alloc_cld_upcall(struct cld_net *cn)
 885{
 886	struct cld_upcall *new, *tmp;
 887
 888	new = kzalloc(sizeof(*new), GFP_KERNEL);
 889	if (!new)
 890		return new;
 891
 892	/* FIXME: hard cap on number in flight? */
 893restart_search:
 894	spin_lock(&cn->cn_lock);
 895	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
 896		if (tmp->cu_msg.cm_xid == cn->cn_xid) {
 897			cn->cn_xid++;
 898			spin_unlock(&cn->cn_lock);
 899			goto restart_search;
 900		}
 901	}
 902	new->cu_task = current;
 903	new->cu_msg.cm_vers = CLD_UPCALL_VERSION;
 904	put_unaligned(cn->cn_xid++, &new->cu_msg.cm_xid);
 905	new->cu_net = cn;
 906	list_add(&new->cu_list, &cn->cn_list);
 907	spin_unlock(&cn->cn_lock);
 908
 909	dprintk("%s: allocated xid %u\n", __func__, new->cu_msg.cm_xid);
 910
 911	return new;
 912}
 913
 914static void
 915free_cld_upcall(struct cld_upcall *victim)
 916{
 917	struct cld_net *cn = victim->cu_net;
 918
 919	spin_lock(&cn->cn_lock);
 920	list_del(&victim->cu_list);
 921	spin_unlock(&cn->cn_lock);
 922	kfree(victim);
 923}
 924
 925/* Ask daemon to create a new record */
 926static void
 927nfsd4_cld_create(struct nfs4_client *clp)
 928{
 929	int ret;
 930	struct cld_upcall *cup;
 931	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 932	struct cld_net *cn = nn->cld_net;
 933
 934	/* Don't upcall if it's already stored */
 935	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 936		return;
 937
 938	cup = alloc_cld_upcall(cn);
 939	if (!cup) {
 940		ret = -ENOMEM;
 941		goto out_err;
 942	}
 943
 944	cup->cu_msg.cm_cmd = Cld_Create;
 945	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
 946	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
 947			clp->cl_name.len);
 948
 949	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
 950	if (!ret) {
 951		ret = cup->cu_msg.cm_status;
 952		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 953	}
 954
 955	free_cld_upcall(cup);
 956out_err:
 957	if (ret)
 958		printk(KERN_ERR "NFSD: Unable to create client "
 959				"record on stable storage: %d\n", ret);
 960}
 961
 962/* Ask daemon to create a new record */
 963static void
 964nfsd4_cld_remove(struct nfs4_client *clp)
 965{
 966	int ret;
 967	struct cld_upcall *cup;
 968	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
 969	struct cld_net *cn = nn->cld_net;
 970
 971	/* Don't upcall if it's already removed */
 972	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
 973		return;
 974
 975	cup = alloc_cld_upcall(cn);
 976	if (!cup) {
 977		ret = -ENOMEM;
 978		goto out_err;
 979	}
 980
 981	cup->cu_msg.cm_cmd = Cld_Remove;
 982	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
 983	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
 984			clp->cl_name.len);
 985
 986	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
 987	if (!ret) {
 988		ret = cup->cu_msg.cm_status;
 989		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
 990	}
 991
 992	free_cld_upcall(cup);
 993out_err:
 994	if (ret)
 995		printk(KERN_ERR "NFSD: Unable to remove client "
 996				"record from stable storage: %d\n", ret);
 997}
 998
 999/* Check for presence of a record, and update its timestamp */
1000static int
1001nfsd4_cld_check(struct nfs4_client *clp)
1002{
1003	int ret;
1004	struct cld_upcall *cup;
1005	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1006	struct cld_net *cn = nn->cld_net;
1007
1008	/* Don't upcall if one was already stored during this grace pd */
1009	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1010		return 0;
1011
1012	cup = alloc_cld_upcall(cn);
1013	if (!cup) {
1014		printk(KERN_ERR "NFSD: Unable to check client record on "
1015				"stable storage: %d\n", -ENOMEM);
1016		return -ENOMEM;
1017	}
1018
1019	cup->cu_msg.cm_cmd = Cld_Check;
1020	cup->cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
1021	memcpy(cup->cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
1022			clp->cl_name.len);
1023
1024	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1025	if (!ret) {
1026		ret = cup->cu_msg.cm_status;
1027		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1028	}
1029
1030	free_cld_upcall(cup);
1031	return ret;
1032}
1033
1034static void
1035nfsd4_cld_grace_done(struct nfsd_net *nn)
1036{
1037	int ret;
1038	struct cld_upcall *cup;
1039	struct cld_net *cn = nn->cld_net;
1040
1041	cup = alloc_cld_upcall(cn);
1042	if (!cup) {
1043		ret = -ENOMEM;
1044		goto out_err;
1045	}
1046
1047	cup->cu_msg.cm_cmd = Cld_GraceDone;
1048	cup->cu_msg.cm_u.cm_gracetime = (int64_t)nn->boot_time;
1049	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_msg);
1050	if (!ret)
1051		ret = cup->cu_msg.cm_status;
1052
1053	free_cld_upcall(cup);
1054out_err:
1055	if (ret)
1056		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
1057}
1058
1059static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
1060	.init		= nfsd4_init_cld_pipe,
1061	.exit		= nfsd4_remove_cld_pipe,
1062	.create		= nfsd4_cld_create,
1063	.remove		= nfsd4_cld_remove,
1064	.check		= nfsd4_cld_check,
1065	.grace_done	= nfsd4_cld_grace_done,
1066};
1067
1068/* upcall via usermodehelper */
1069static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
1070module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
1071			S_IRUGO|S_IWUSR);
1072MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
1073
1074static bool cltrack_legacy_disable;
1075module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
1076MODULE_PARM_DESC(cltrack_legacy_disable,
1077		"Disable legacy recoverydir conversion. Default: false");
1078
1079#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
1080#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
1081#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
1082#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
1083
1084static char *
1085nfsd4_cltrack_legacy_topdir(void)
1086{
1087	int copied;
1088	size_t len;
1089	char *result;
1090
1091	if (cltrack_legacy_disable)
1092		return NULL;
1093
1094	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
1095		strlen(nfs4_recoverydir()) + 1;
1096
1097	result = kmalloc(len, GFP_KERNEL);
1098	if (!result)
1099		return result;
1100
1101	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
1102				nfs4_recoverydir());
1103	if (copied >= len) {
1104		/* just return nothing if output was truncated */
1105		kfree(result);
1106		return NULL;
1107	}
1108
1109	return result;
1110}
1111
1112static char *
1113nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
1114{
1115	int copied;
1116	size_t len;
1117	char *result;
1118
1119	if (cltrack_legacy_disable)
1120		return NULL;
1121
1122	/* +1 is for '/' between "topdir" and "recdir" */
1123	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
1124		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
1125
1126	result = kmalloc(len, GFP_KERNEL);
1127	if (!result)
1128		return result;
1129
1130	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
1131				nfs4_recoverydir());
1132	if (copied > (len - HEXDIR_LEN)) {
1133		/* just return nothing if output will be truncated */
1134		kfree(result);
1135		return NULL;
1136	}
1137
1138	copied = nfs4_make_rec_clidname(result + copied, name);
1139	if (copied) {
1140		kfree(result);
1141		return NULL;
1142	}
1143
1144	return result;
1145}
1146
1147static char *
1148nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
1149{
1150	int copied;
1151	size_t len;
1152	char *result;
1153
1154	/* prefix + Y/N character + terminating NULL */
1155	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
1156
1157	result = kmalloc(len, GFP_KERNEL);
1158	if (!result)
1159		return result;
1160
1161	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
1162				clp->cl_minorversion ? 'Y' : 'N');
1163	if (copied >= len) {
1164		/* just return nothing if output was truncated */
1165		kfree(result);
1166		return NULL;
1167	}
1168
1169	return result;
1170}
1171
1172static char *
1173nfsd4_cltrack_grace_start(time_t grace_start)
1174{
1175	int copied;
1176	size_t len;
1177	char *result;
1178
1179	/* prefix + max width of int64_t string + terminating NULL */
1180	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
1181
1182	result = kmalloc(len, GFP_KERNEL);
1183	if (!result)
1184		return result;
1185
1186	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%ld",
1187				grace_start);
1188	if (copied >= len) {
1189		/* just return nothing if output was truncated */
1190		kfree(result);
1191		return NULL;
1192	}
1193
1194	return result;
1195}
1196
1197static int
1198nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
1199{
1200	char *envp[3];
1201	char *argv[4];
1202	int ret;
1203
1204	if (unlikely(!cltrack_prog[0])) {
1205		dprintk("%s: cltrack_prog is disabled\n", __func__);
1206		return -EACCES;
1207	}
1208
1209	dprintk("%s: cmd: %s\n", __func__, cmd);
1210	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
1211	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
1212	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
1213
1214	envp[0] = env0;
1215	envp[1] = env1;
1216	envp[2] = NULL;
1217
1218	argv[0] = (char *)cltrack_prog;
1219	argv[1] = cmd;
1220	argv[2] = arg;
1221	argv[3] = NULL;
1222
1223	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
1224	/*
1225	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
1226	 * error. The admin can re-enable it on the fly by using sysfs
1227	 * once the problem has been fixed.
1228	 */
1229	if (ret == -ENOENT || ret == -EACCES) {
1230		dprintk("NFSD: %s was not found or isn't executable (%d). "
1231			"Setting cltrack_prog to blank string!",
1232			cltrack_prog, ret);
1233		cltrack_prog[0] = '\0';
1234	}
1235	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
1236
1237	return ret;
1238}
1239
1240static char *
1241bin_to_hex_dup(const unsigned char *src, int srclen)
1242{
1243	int i;
1244	char *buf, *hex;
1245
1246	/* +1 for terminating NULL */
1247	buf = kmalloc((srclen * 2) + 1, GFP_KERNEL);
1248	if (!buf)
1249		return buf;
1250
1251	hex = buf;
1252	for (i = 0; i < srclen; i++) {
1253		sprintf(hex, "%2.2x", *src++);
1254		hex += 2;
1255	}
1256	return buf;
1257}
1258
1259static int
1260nfsd4_umh_cltrack_init(struct net *net)
1261{
1262	int ret;
1263	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1264	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1265
1266	/* XXX: The usermode helper s not working in container yet. */
1267	if (net != &init_net) {
1268		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
1269		kfree(grace_start);
1270		return -EINVAL;
1271	}
1272
1273	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
1274	kfree(grace_start);
1275	return ret;
1276}
1277
1278static void
1279nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
1280{
1281	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
1282			 TASK_UNINTERRUPTIBLE);
1283}
1284
1285static void
1286nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
1287{
1288	smp_mb__before_atomic();
1289	clear_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
1290	smp_mb__after_atomic();
1291	wake_up_bit(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK);
1292}
1293
1294static void
1295nfsd4_umh_cltrack_create(struct nfs4_client *clp)
1296{
1297	char *hexid, *has_session, *grace_start;
1298	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1299
1300	/*
1301	 * With v4.0 clients, there's little difference in outcome between a
1302	 * create and check operation, and we can end up calling into this
1303	 * function multiple times per client (once for each openowner). So,
1304	 * for v4.0 clients skip upcalling once the client has been recorded
1305	 * on stable storage.
1306	 *
1307	 * For v4.1+ clients, the outcome of the two operations is different,
1308	 * so we must ensure that we upcall for the create operation. v4.1+
1309	 * clients call this on RECLAIM_COMPLETE though, so we should only end
1310	 * up doing a single create upcall per client.
1311	 */
1312	if (clp->cl_minorversion == 0 &&
1313	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1314		return;
1315
1316	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1317	if (!hexid) {
1318		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1319		return;
1320	}
1321
1322	has_session = nfsd4_cltrack_client_has_session(clp);
1323	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
1324
1325	nfsd4_cltrack_upcall_lock(clp);
1326	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
1327		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1328	nfsd4_cltrack_upcall_unlock(clp);
1329
1330	kfree(has_session);
1331	kfree(grace_start);
1332	kfree(hexid);
1333}
1334
1335static void
1336nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
1337{
1338	char *hexid;
1339
1340	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1341		return;
1342
1343	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1344	if (!hexid) {
1345		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1346		return;
1347	}
1348
1349	nfsd4_cltrack_upcall_lock(clp);
1350	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
1351	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
1352		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1353	nfsd4_cltrack_upcall_unlock(clp);
1354
1355	kfree(hexid);
1356}
1357
1358static int
1359nfsd4_umh_cltrack_check(struct nfs4_client *clp)
1360{
1361	int ret;
1362	char *hexid, *has_session, *legacy;
1363
1364	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
1365		return 0;
1366
1367	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
1368	if (!hexid) {
1369		dprintk("%s: can't allocate memory for upcall!\n", __func__);
1370		return -ENOMEM;
1371	}
1372
1373	has_session = nfsd4_cltrack_client_has_session(clp);
1374	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
1375
1376	nfsd4_cltrack_upcall_lock(clp);
1377	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
1378		ret = 0;
1379	} else {
1380		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
1381		if (ret == 0)
1382			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
1383	}
1384	nfsd4_cltrack_upcall_unlock(clp);
1385	kfree(has_session);
1386	kfree(legacy);
1387	kfree(hexid);
1388
1389	return ret;
1390}
1391
1392static void
1393nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
 
1394{
1395	char *legacy;
1396	char timestr[22]; /* FIXME: better way to determine max size? */
1397
1398	sprintf(timestr, "%ld", nn->boot_time);
1399	legacy = nfsd4_cltrack_legacy_topdir();
1400	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
1401	kfree(legacy);
1402}
1403
1404static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
1405	.init		= nfsd4_umh_cltrack_init,
1406	.exit		= NULL,
1407	.create		= nfsd4_umh_cltrack_create,
1408	.remove		= nfsd4_umh_cltrack_remove,
1409	.check		= nfsd4_umh_cltrack_check,
1410	.grace_done	= nfsd4_umh_cltrack_grace_done,
1411};
1412
1413int
1414nfsd4_client_tracking_init(struct net *net)
1415{
1416	int status;
1417	struct path path;
1418	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1419
1420	/* just run the init if it the method is already decided */
1421	if (nn->client_tracking_ops)
1422		goto do_init;
1423
1424	/*
1425	 * First, try a UMH upcall. It should succeed or fail quickly, so
1426	 * there's little harm in trying that first.
1427	 */
1428	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
1429	status = nn->client_tracking_ops->init(net);
1430	if (!status)
1431		return status;
1432
1433	/*
1434	 * See if the recoverydir exists and is a directory. If it is,
1435	 * then use the legacy ops.
1436	 */
1437	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
1438	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
1439	if (!status) {
1440		status = d_is_dir(path.dentry);
1441		path_put(&path);
1442		if (status)
1443			goto do_init;
1444	}
1445
1446	/* Finally, try to use nfsdcld */
1447	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
1448	printk(KERN_WARNING "NFSD: the nfsdcld client tracking upcall will be "
1449			"removed in 3.10. Please transition to using "
1450			"nfsdcltrack.\n");
1451do_init:
1452	status = nn->client_tracking_ops->init(net);
1453	if (status) {
1454		printk(KERN_WARNING "NFSD: Unable to initialize client "
1455				    "recovery tracking! (%d)\n", status);
1456		nn->client_tracking_ops = NULL;
1457	}
1458	return status;
1459}
1460
1461void
1462nfsd4_client_tracking_exit(struct net *net)
1463{
1464	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1465
1466	if (nn->client_tracking_ops) {
1467		if (nn->client_tracking_ops->exit)
1468			nn->client_tracking_ops->exit(net);
1469		nn->client_tracking_ops = NULL;
1470	}
1471}
1472
1473void
1474nfsd4_client_record_create(struct nfs4_client *clp)
1475{
1476	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1477
1478	if (nn->client_tracking_ops)
1479		nn->client_tracking_ops->create(clp);
1480}
1481
1482void
1483nfsd4_client_record_remove(struct nfs4_client *clp)
1484{
1485	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1486
1487	if (nn->client_tracking_ops)
1488		nn->client_tracking_ops->remove(clp);
1489}
1490
1491int
1492nfsd4_client_record_check(struct nfs4_client *clp)
1493{
1494	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
1495
1496	if (nn->client_tracking_ops)
1497		return nn->client_tracking_ops->check(clp);
1498
1499	return -EOPNOTSUPP;
1500}
1501
1502void
1503nfsd4_record_grace_done(struct nfsd_net *nn)
1504{
1505	if (nn->client_tracking_ops)
1506		nn->client_tracking_ops->grace_done(nn);
1507}
1508
1509static int
1510rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
1511{
1512	struct super_block *sb = ptr;
1513	struct net *net = sb->s_fs_info;
1514	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1515	struct cld_net *cn = nn->cld_net;
1516	struct dentry *dentry;
1517	int ret = 0;
1518
1519	if (!try_module_get(THIS_MODULE))
1520		return 0;
1521
1522	if (!cn) {
1523		module_put(THIS_MODULE);
1524		return 0;
1525	}
1526
1527	switch (event) {
1528	case RPC_PIPEFS_MOUNT:
1529		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
1530		if (IS_ERR(dentry)) {
1531			ret = PTR_ERR(dentry);
1532			break;
1533		}
1534		cn->cn_pipe->dentry = dentry;
1535		break;
1536	case RPC_PIPEFS_UMOUNT:
1537		if (cn->cn_pipe->dentry)
1538			nfsd4_cld_unregister_sb(cn->cn_pipe);
1539		break;
1540	default:
1541		ret = -ENOTSUPP;
1542		break;
1543	}
1544	module_put(THIS_MODULE);
1545	return ret;
1546}
1547
1548static struct notifier_block nfsd4_cld_block = {
1549	.notifier_call = rpc_pipefs_event,
1550};
1551
1552int
1553register_cld_notifier(void)
1554{
1555	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
1556}
1557
1558void
1559unregister_cld_notifier(void)
1560{
1561	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
1562}