1/*
   2 *  linux/fs/9p/vfs_inode.c
   3 *
   4 * This file contains vfs inode ops for the 9P2000 protocol.
   5 *
   6 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   7 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   8 *
   9 *  This program is free software; you can redistribute it and/or modify
  10 *  it under the terms of the GNU General Public License version 2
  11 *  as published by the Free Software Foundation.
  12 *
  13 *  This program is distributed in the hope that it will be useful,
  14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 *  GNU General Public License for more details.
  17 *
  18 *  You should have received a copy of the GNU General Public License
  19 *  along with this program; if not, write to:
  20 *  Free Software Foundation
  21 *  51 Franklin Street, Fifth Floor
  22 *  Boston, MA  02111-1301  USA
  23 *
  24 */
  25
  26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28#include <linux/module.h>
  29#include <linux/errno.h>
  30#include <linux/fs.h>
  31#include <linux/file.h>
  32#include <linux/pagemap.h>
  33#include <linux/stat.h>
  34#include <linux/string.h>
  35#include <linux/inet.h>
  36#include <linux/namei.h>
  37#include <linux/idr.h>
  38#include <linux/sched.h>
  39#include <linux/slab.h>
  40#include <linux/xattr.h>
  41#include <linux/posix_acl.h>
  42#include <net/9p/9p.h>
  43#include <net/9p/client.h>
  44
  45#include "v9fs.h"
  46#include "v9fs_vfs.h"
  47#include "fid.h"
  48#include "cache.h"
  49#include "xattr.h"
  50#include "acl.h"
  51
  52static const struct inode_operations v9fs_dir_inode_operations;
  53static const struct inode_operations v9fs_dir_inode_operations_dotu;
  54static const struct inode_operations v9fs_file_inode_operations;
  55static const struct inode_operations v9fs_symlink_inode_operations;
  56
  57/**
  58 * unixmode2p9mode - convert unix mode bits to plan 9
  59 * @v9ses: v9fs session information
  60 * @mode: mode to convert
  61 *
  62 */
  63
  64static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
  65{
  66	int res;
  67	res = mode & 0777;
  68	if (S_ISDIR(mode))
  69		res |= P9_DMDIR;
  70	if (v9fs_proto_dotu(v9ses)) {
  71		if (v9ses->nodev == 0) {
  72			if (S_ISSOCK(mode))
  73				res |= P9_DMSOCKET;
  74			if (S_ISFIFO(mode))
  75				res |= P9_DMNAMEDPIPE;
  76			if (S_ISBLK(mode))
  77				res |= P9_DMDEVICE;
  78			if (S_ISCHR(mode))
  79				res |= P9_DMDEVICE;
  80		}
  81
  82		if ((mode & S_ISUID) == S_ISUID)
  83			res |= P9_DMSETUID;
  84		if ((mode & S_ISGID) == S_ISGID)
  85			res |= P9_DMSETGID;
  86		if ((mode & S_ISVTX) == S_ISVTX)
  87			res |= P9_DMSETVTX;
  88	}
  89	return res;
  90}
  91
  92/**
  93 * p9mode2perm- convert plan9 mode bits to unix permission bits
  94 * @v9ses: v9fs session information
  95 * @stat: p9_wstat from which mode need to be derived
  96 *
  97 */
  98static int p9mode2perm(struct v9fs_session_info *v9ses,
  99		       struct p9_wstat *stat)
 100{
 101	int res;
 102	int mode = stat->mode;
 103
 104	res = mode & S_IALLUGO;
 105	if (v9fs_proto_dotu(v9ses)) {
 106		if ((mode & P9_DMSETUID) == P9_DMSETUID)
 107			res |= S_ISUID;
 108
 109		if ((mode & P9_DMSETGID) == P9_DMSETGID)
 110			res |= S_ISGID;
 111
 112		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 113			res |= S_ISVTX;
 114	}
 115	return res;
 116}
 117
 118/**
 119 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 120 * @v9ses: v9fs session information
 121 * @stat: p9_wstat from which mode need to be derived
 122 * @rdev: major number, minor number in case of device files.
 123 *
 124 */
 125static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 126			       struct p9_wstat *stat, dev_t *rdev)
 127{
 128	int res;
 129	u32 mode = stat->mode;
 130
 131	*rdev = 0;
 132	res = p9mode2perm(v9ses, stat);
 133
 134	if ((mode & P9_DMDIR) == P9_DMDIR)
 135		res |= S_IFDIR;
 136	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 137		res |= S_IFLNK;
 138	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 139		 && (v9ses->nodev == 0))
 140		res |= S_IFSOCK;
 141	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 142		 && (v9ses->nodev == 0))
 143		res |= S_IFIFO;
 144	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 145		 && (v9ses->nodev == 0)) {
 146		char type = 0, ext[32];
 147		int major = -1, minor = -1;
 148
 149		strlcpy(ext, stat->extension, sizeof(ext));
 150		sscanf(ext, "%c %i %i", &type, &major, &minor);
 151		switch (type) {
 152		case 'c':
 153			res |= S_IFCHR;
 154			break;
 155		case 'b':
 156			res |= S_IFBLK;
 157			break;
 158		default:
 159			p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 160				 type, stat->extension);
 161		};
 162		*rdev = MKDEV(major, minor);
 163	} else
 164		res |= S_IFREG;
 165
 166	return res;
 167}
 168
 169/**
 170 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 171 * @uflags: flags to convert
 172 * @extended: if .u extensions are active
 173 */
 174
 175int v9fs_uflags2omode(int uflags, int extended)
 176{
 177	int ret;
 178
 179	ret = 0;
 180	switch (uflags&3) {
 181	default:
 182	case O_RDONLY:
 183		ret = P9_OREAD;
 184		break;
 185
 186	case O_WRONLY:
 187		ret = P9_OWRITE;
 188		break;
 189
 190	case O_RDWR:
 191		ret = P9_ORDWR;
 192		break;
 193	}
 194
 195	if (extended) {
 196		if (uflags & O_EXCL)
 197			ret |= P9_OEXCL;
 198
 199		if (uflags & O_APPEND)
 200			ret |= P9_OAPPEND;
 201	}
 202
 203	return ret;
 204}
 205
 206/**
 207 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 208 * @wstat: structure to initialize
 209 *
 210 */
 211
 212void
 213v9fs_blank_wstat(struct p9_wstat *wstat)
 214{
 215	wstat->type = ~0;
 216	wstat->dev = ~0;
 217	wstat->qid.type = ~0;
 218	wstat->qid.version = ~0;
 219	*((long long *)&wstat->qid.path) = ~0;
 220	wstat->mode = ~0;
 221	wstat->atime = ~0;
 222	wstat->mtime = ~0;
 223	wstat->length = ~0;
 224	wstat->name = NULL;
 225	wstat->uid = NULL;
 226	wstat->gid = NULL;
 227	wstat->muid = NULL;
 228	wstat->n_uid = INVALID_UID;
 229	wstat->n_gid = INVALID_GID;
 230	wstat->n_muid = INVALID_UID;
 231	wstat->extension = NULL;
 232}
 233
 234/**
 235 * v9fs_alloc_inode - helper function to allocate an inode
 236 *
 237 */
 238struct inode *v9fs_alloc_inode(struct super_block *sb)
 239{
 240	struct v9fs_inode *v9inode;
 241	v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 242							GFP_KERNEL);
 243	if (!v9inode)
 244		return NULL;
 245#ifdef CONFIG_9P_FSCACHE
 246	v9inode->fscache = NULL;
 247	mutex_init(&v9inode->fscache_lock);
 248#endif
 249	v9inode->writeback_fid = NULL;
 250	v9inode->cache_validity = 0;
 251	mutex_init(&v9inode->v_mutex);
 252	return &v9inode->vfs_inode;
 253}
 254
 255/**
 256 * v9fs_destroy_inode - destroy an inode
 257 *
 258 */
 259
 260static void v9fs_i_callback(struct rcu_head *head)
 261{
 262	struct inode *inode = container_of(head, struct inode, i_rcu);
 263	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 264}
 265
 266void v9fs_destroy_inode(struct inode *inode)
 267{
 268	call_rcu(&inode->i_rcu, v9fs_i_callback);
 269}
 270
 271int v9fs_init_inode(struct v9fs_session_info *v9ses,
 272		    struct inode *inode, umode_t mode, dev_t rdev)
 273{
 274	int err = 0;
 275
 276	inode_init_owner(inode, NULL, mode);
 277	inode->i_blocks = 0;
 278	inode->i_rdev = rdev;
 279	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 280	inode->i_mapping->a_ops = &v9fs_addr_operations;
 281
 282	switch (mode & S_IFMT) {
 283	case S_IFIFO:
 284	case S_IFBLK:
 285	case S_IFCHR:
 286	case S_IFSOCK:
 287		if (v9fs_proto_dotl(v9ses)) {
 288			inode->i_op = &v9fs_file_inode_operations_dotl;
 289		} else if (v9fs_proto_dotu(v9ses)) {
 290			inode->i_op = &v9fs_file_inode_operations;
 291		} else {
 292			p9_debug(P9_DEBUG_ERROR,
 293				 "special files without extended mode\n");
 294			err = -EINVAL;
 295			goto error;
 296		}
 297		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 298		break;
 299	case S_IFREG:
 300		if (v9fs_proto_dotl(v9ses)) {
 301			inode->i_op = &v9fs_file_inode_operations_dotl;
 302			if (v9ses->cache == CACHE_LOOSE ||
 303			    v9ses->cache == CACHE_FSCACHE)
 304				inode->i_fop =
 305					&v9fs_cached_file_operations_dotl;
 306			else if (v9ses->cache == CACHE_MMAP)
 307				inode->i_fop = &v9fs_mmap_file_operations_dotl;
 308			else
 309				inode->i_fop = &v9fs_file_operations_dotl;
 310		} else {
 311			inode->i_op = &v9fs_file_inode_operations;
 312			if (v9ses->cache == CACHE_LOOSE ||
 313			    v9ses->cache == CACHE_FSCACHE)
 314				inode->i_fop =
 315					&v9fs_cached_file_operations;
 316			else if (v9ses->cache == CACHE_MMAP)
 317				inode->i_fop = &v9fs_mmap_file_operations;
 318			else
 319				inode->i_fop = &v9fs_file_operations;
 320		}
 321
 322		break;
 323	case S_IFLNK:
 324		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 325			p9_debug(P9_DEBUG_ERROR,
 326				 "extended modes used with legacy protocol\n");
 327			err = -EINVAL;
 328			goto error;
 329		}
 330
 331		if (v9fs_proto_dotl(v9ses))
 332			inode->i_op = &v9fs_symlink_inode_operations_dotl;
 333		else
 334			inode->i_op = &v9fs_symlink_inode_operations;
 335
 336		break;
 337	case S_IFDIR:
 338		inc_nlink(inode);
 339		if (v9fs_proto_dotl(v9ses))
 340			inode->i_op = &v9fs_dir_inode_operations_dotl;
 341		else if (v9fs_proto_dotu(v9ses))
 342			inode->i_op = &v9fs_dir_inode_operations_dotu;
 343		else
 344			inode->i_op = &v9fs_dir_inode_operations;
 345
 346		if (v9fs_proto_dotl(v9ses))
 347			inode->i_fop = &v9fs_dir_operations_dotl;
 348		else
 349			inode->i_fop = &v9fs_dir_operations;
 350
 351		break;
 352	default:
 353		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 354			 mode, mode & S_IFMT);
 355		err = -EINVAL;
 356		goto error;
 357	}
 358error:
 359	return err;
 360
 361}
 362
 363/**
 364 * v9fs_get_inode - helper function to setup an inode
 365 * @sb: superblock
 366 * @mode: mode to setup inode with
 367 *
 368 */
 369
 370struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 371{
 372	int err;
 373	struct inode *inode;
 374	struct v9fs_session_info *v9ses = sb->s_fs_info;
 375
 376	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 377
 378	inode = new_inode(sb);
 379	if (!inode) {
 380		pr_warn("%s (%d): Problem allocating inode\n",
 381			__func__, task_pid_nr(current));
 382		return ERR_PTR(-ENOMEM);
 383	}
 384	err = v9fs_init_inode(v9ses, inode, mode, rdev);
 385	if (err) {
 386		iput(inode);
 387		return ERR_PTR(err);
 388	}
 389	return inode;
 390}
 391
 392/*
 393static struct v9fs_fid*
 394v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 395{
 396	int err;
 397	int nfid;
 398	struct v9fs_fid *ret;
 399	struct v9fs_fcall *fcall;
 400
 401	nfid = v9fs_get_idpool(&v9ses->fidpool);
 402	if (nfid < 0) {
 403		eprintk(KERN_WARNING, "no free fids available\n");
 404		return ERR_PTR(-ENOSPC);
 405	}
 406
 407	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 408		&fcall);
 409
 410	if (err < 0) {
 411		if (fcall && fcall->id == RWALK)
 412			goto clunk_fid;
 413
 414		PRINT_FCALL_ERROR("walk error", fcall);
 415		v9fs_put_idpool(nfid, &v9ses->fidpool);
 416		goto error;
 417	}
 418
 419	kfree(fcall);
 420	fcall = NULL;
 421	ret = v9fs_fid_create(v9ses, nfid);
 422	if (!ret) {
 423		err = -ENOMEM;
 424		goto clunk_fid;
 425	}
 426
 427	err = v9fs_fid_insert(ret, dentry);
 428	if (err < 0) {
 429		v9fs_fid_destroy(ret);
 430		goto clunk_fid;
 431	}
 432
 433	return ret;
 434
 435clunk_fid:
 436	v9fs_t_clunk(v9ses, nfid);
 437
 438error:
 439	kfree(fcall);
 440	return ERR_PTR(err);
 441}
 442*/
 443
 444
 445/**
 446 * v9fs_clear_inode - release an inode
 447 * @inode: inode to release
 448 *
 449 */
 450void v9fs_evict_inode(struct inode *inode)
 451{
 452	struct v9fs_inode *v9inode = V9FS_I(inode);
 453
 454	truncate_inode_pages_final(&inode->i_data);
 455	clear_inode(inode);
 456	filemap_fdatawrite(&inode->i_data);
 457
 458	v9fs_cache_inode_put_cookie(inode);
 459	/* clunk the fid stashed in writeback_fid */
 460	if (v9inode->writeback_fid) {
 461		p9_client_clunk(v9inode->writeback_fid);
 462		v9inode->writeback_fid = NULL;
 463	}
 464}
 465
 466static int v9fs_test_inode(struct inode *inode, void *data)
 467{
 468	int umode;
 469	dev_t rdev;
 470	struct v9fs_inode *v9inode = V9FS_I(inode);
 471	struct p9_wstat *st = (struct p9_wstat *)data;
 472	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 473
 474	umode = p9mode2unixmode(v9ses, st, &rdev);
 475	/* don't match inode of different type */
 476	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 477		return 0;
 478
 479	/* compare qid details */
 480	if (memcmp(&v9inode->qid.version,
 481		   &st->qid.version, sizeof(v9inode->qid.version)))
 482		return 0;
 483
 484	if (v9inode->qid.type != st->qid.type)
 485		return 0;
 486	return 1;
 487}
 488
 489static int v9fs_test_new_inode(struct inode *inode, void *data)
 490{
 491	return 0;
 492}
 493
 494static int v9fs_set_inode(struct inode *inode,  void *data)
 495{
 496	struct v9fs_inode *v9inode = V9FS_I(inode);
 497	struct p9_wstat *st = (struct p9_wstat *)data;
 498
 499	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 500	return 0;
 501}
 502
 503static struct inode *v9fs_qid_iget(struct super_block *sb,
 504				   struct p9_qid *qid,
 505				   struct p9_wstat *st,
 506				   int new)
 507{
 508	dev_t rdev;
 509	int retval;
 510	umode_t umode;
 511	unsigned long i_ino;
 512	struct inode *inode;
 513	struct v9fs_session_info *v9ses = sb->s_fs_info;
 514	int (*test)(struct inode *, void *);
 515
 516	if (new)
 517		test = v9fs_test_new_inode;
 518	else
 519		test = v9fs_test_inode;
 520
 521	i_ino = v9fs_qid2ino(qid);
 522	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 523	if (!inode)
 524		return ERR_PTR(-ENOMEM);
 525	if (!(inode->i_state & I_NEW))
 526		return inode;
 527	/*
 528	 * initialize the inode with the stat info
 529	 * FIXME!! we may need support for stale inodes
 530	 * later.
 531	 */
 532	inode->i_ino = i_ino;
 533	umode = p9mode2unixmode(v9ses, st, &rdev);
 534	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 535	if (retval)
 536		goto error;
 537
 538	v9fs_stat2inode(st, inode, sb);
 539	v9fs_cache_inode_get_cookie(inode);
 540	unlock_new_inode(inode);
 541	return inode;
 542error:
 543	iget_failed(inode);
 544	return ERR_PTR(retval);
 545
 546}
 547
 548struct inode *
 549v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 550		    struct super_block *sb, int new)
 551{
 552	struct p9_wstat *st;
 553	struct inode *inode = NULL;
 554
 555	st = p9_client_stat(fid);
 556	if (IS_ERR(st))
 557		return ERR_CAST(st);
 558
 559	inode = v9fs_qid_iget(sb, &st->qid, st, new);
 560	p9stat_free(st);
 561	kfree(st);
 562	return inode;
 563}
 564
 565/**
 566 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 567 * plan 9 AT flag.
 568 * @flags: flags to convert
 569 */
 570static int v9fs_at_to_dotl_flags(int flags)
 571{
 572	int rflags = 0;
 573	if (flags & AT_REMOVEDIR)
 574		rflags |= P9_DOTL_AT_REMOVEDIR;
 575	return rflags;
 576}
 577
 578/**
 579 * v9fs_remove - helper function to remove files and directories
 580 * @dir: directory inode that is being deleted
 581 * @dentry:  dentry that is being deleted
 582 * @flags: removing a directory
 583 *
 584 */
 585
 586static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 587{
 588	struct inode *inode;
 589	int retval = -EOPNOTSUPP;
 590	struct p9_fid *v9fid, *dfid;
 591	struct v9fs_session_info *v9ses;
 592
 593	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 594		 dir, dentry, flags);
 595
 596	v9ses = v9fs_inode2v9ses(dir);
 597	inode = d_inode(dentry);
 598	dfid = v9fs_fid_lookup(dentry->d_parent);
 599	if (IS_ERR(dfid)) {
 600		retval = PTR_ERR(dfid);
 601		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 602		return retval;
 603	}
 604	if (v9fs_proto_dotl(v9ses))
 605		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 606					    v9fs_at_to_dotl_flags(flags));
 607	if (retval == -EOPNOTSUPP) {
 608		/* Try the one based on path */
 609		v9fid = v9fs_fid_clone(dentry);
 610		if (IS_ERR(v9fid))
 611			return PTR_ERR(v9fid);
 612		retval = p9_client_remove(v9fid);
 613	}
 614	if (!retval) {
 615		/*
 616		 * directories on unlink should have zero
 617		 * link count
 618		 */
 619		if (flags & AT_REMOVEDIR) {
 620			clear_nlink(inode);
 621			drop_nlink(dir);
 622		} else
 623			drop_nlink(inode);
 624
 625		v9fs_invalidate_inode_attr(inode);
 626		v9fs_invalidate_inode_attr(dir);
 627	}
 628	return retval;
 629}
 630
 631/**
 632 * v9fs_create - Create a file
 633 * @v9ses: session information
 634 * @dir: directory that dentry is being created in
 635 * @dentry:  dentry that is being created
 636 * @extension: 9p2000.u extension string to support devices, etc.
 637 * @perm: create permissions
 638 * @mode: open mode
 639 *
 640 */
 641static struct p9_fid *
 642v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 643		struct dentry *dentry, char *extension, u32 perm, u8 mode)
 644{
 645	int err;
 646	char *name;
 647	struct p9_fid *dfid, *ofid, *fid;
 648	struct inode *inode;
 649
 650	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 651
 652	err = 0;
 653	ofid = NULL;
 654	fid = NULL;
 655	name = (char *) dentry->d_name.name;
 656	dfid = v9fs_fid_lookup(dentry->d_parent);
 657	if (IS_ERR(dfid)) {
 658		err = PTR_ERR(dfid);
 659		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 660		return ERR_PTR(err);
 661	}
 662
 663	/* clone a fid to use for creation */
 664	ofid = p9_client_walk(dfid, 0, NULL, 1);
 665	if (IS_ERR(ofid)) {
 666		err = PTR_ERR(ofid);
 667		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 668		return ERR_PTR(err);
 669	}
 670
 671	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 672	if (err < 0) {
 673		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 674		goto error;
 675	}
 676
 677	if (!(perm & P9_DMLINK)) {
 678		/* now walk from the parent so we can get unopened fid */
 679		fid = p9_client_walk(dfid, 1, &name, 1);
 680		if (IS_ERR(fid)) {
 681			err = PTR_ERR(fid);
 682			p9_debug(P9_DEBUG_VFS,
 683				   "p9_client_walk failed %d\n", err);
 684			fid = NULL;
 685			goto error;
 686		}
 687		/*
 688		 * instantiate inode and assign the unopened fid to the dentry
 689		 */
 690		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 691		if (IS_ERR(inode)) {
 692			err = PTR_ERR(inode);
 693			p9_debug(P9_DEBUG_VFS,
 694				   "inode creation failed %d\n", err);
 695			goto error;
 696		}
 697		v9fs_fid_add(dentry, fid);
 698		d_instantiate(dentry, inode);
 699	}
 700	return ofid;
 701error:
 702	if (ofid)
 703		p9_client_clunk(ofid);
 704
 705	if (fid)
 706		p9_client_clunk(fid);
 707
 708	return ERR_PTR(err);
 709}
 710
 711/**
 712 * v9fs_vfs_create - VFS hook to create a regular file
 713 *
 714 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 715 * for mknod(2).
 716 *
 717 * @dir: directory inode that is being created
 718 * @dentry:  dentry that is being deleted
 719 * @mode: create permissions
 720 *
 721 */
 722
 723static int
 724v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 725		bool excl)
 726{
 727	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 728	u32 perm = unixmode2p9mode(v9ses, mode);
 729	struct p9_fid *fid;
 730
 731	/* P9_OEXCL? */
 732	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 733	if (IS_ERR(fid))
 734		return PTR_ERR(fid);
 735
 736	v9fs_invalidate_inode_attr(dir);
 737	p9_client_clunk(fid);
 738
 739	return 0;
 740}
 741
 742/**
 743 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 744 * @dir:  inode that is being unlinked
 745 * @dentry: dentry that is being unlinked
 746 * @mode: mode for new directory
 747 *
 748 */
 749
 750static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 751{
 752	int err;
 753	u32 perm;
 754	struct p9_fid *fid;
 755	struct v9fs_session_info *v9ses;
 756
 757	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 758	err = 0;
 759	v9ses = v9fs_inode2v9ses(dir);
 760	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 761	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 762	if (IS_ERR(fid)) {
 763		err = PTR_ERR(fid);
 764		fid = NULL;
 765	} else {
 766		inc_nlink(dir);
 767		v9fs_invalidate_inode_attr(dir);
 768	}
 769
 770	if (fid)
 771		p9_client_clunk(fid);
 772
 773	return err;
 774}
 775
 776/**
 777 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 778 * @dir:  inode that is being walked from
 779 * @dentry: dentry that is being walked to?
 780 * @flags: lookup flags (unused)
 781 *
 782 */
 783
 784struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 785				      unsigned int flags)
 786{
 787	struct dentry *res;
 788	struct v9fs_session_info *v9ses;
 789	struct p9_fid *dfid, *fid;
 790	struct inode *inode;
 791	char *name;
 792
 793	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
 794		 dir, dentry, dentry, flags);
 795
 796	if (dentry->d_name.len > NAME_MAX)
 797		return ERR_PTR(-ENAMETOOLONG);
 798
 799	v9ses = v9fs_inode2v9ses(dir);
 800	/* We can walk d_parent because we hold the dir->i_mutex */
 801	dfid = v9fs_fid_lookup(dentry->d_parent);
 802	if (IS_ERR(dfid))
 803		return ERR_CAST(dfid);
 804
 805	name = (char *) dentry->d_name.name;
 806	fid = p9_client_walk(dfid, 1, &name, 1);
 807	if (IS_ERR(fid)) {
 808		if (fid == ERR_PTR(-ENOENT)) {
 809			d_add(dentry, NULL);
 810			return NULL;
 811		}
 812		return ERR_CAST(fid);
 813	}
 814	/*
 815	 * Make sure we don't use a wrong inode due to parallel
 816	 * unlink. For cached mode create calls request for new
 817	 * inode. But with cache disabled, lookup should do this.
 818	 */
 819	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 820		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 821	else
 822		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 823	if (IS_ERR(inode)) {
 824		p9_client_clunk(fid);
 825		return ERR_CAST(inode);
 826	}
 827	/*
 828	 * If we had a rename on the server and a parallel lookup
 829	 * for the new name, then make sure we instantiate with
 830	 * the new name. ie look up for a/b, while on server somebody
 831	 * moved b under k and client parallely did a lookup for
 832	 * k/b.
 833	 */
 834	res = d_splice_alias(inode, dentry);
 835	if (!res)
 836		v9fs_fid_add(dentry, fid);
 837	else if (!IS_ERR(res))
 838		v9fs_fid_add(res, fid);
 839	else
 840		p9_client_clunk(fid);
 841	return res;
 842}
 843
 844static int
 845v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 846		     struct file *file, unsigned flags, umode_t mode,
 847		     int *opened)
 848{
 849	int err;
 850	u32 perm;
 851	struct v9fs_inode *v9inode;
 852	struct v9fs_session_info *v9ses;
 853	struct p9_fid *fid, *inode_fid;
 854	struct dentry *res = NULL;
 855
 856	if (d_unhashed(dentry)) {
 857		res = v9fs_vfs_lookup(dir, dentry, 0);
 858		if (IS_ERR(res))
 859			return PTR_ERR(res);
 860
 861		if (res)
 862			dentry = res;
 863	}
 864
 865	/* Only creates */
 866	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
 867		return finish_no_open(file, res);
 868
 869	err = 0;
 870
 871	v9ses = v9fs_inode2v9ses(dir);
 872	perm = unixmode2p9mode(v9ses, mode);
 873	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 874				v9fs_uflags2omode(flags,
 875						v9fs_proto_dotu(v9ses)));
 876	if (IS_ERR(fid)) {
 877		err = PTR_ERR(fid);
 878		fid = NULL;
 879		goto error;
 880	}
 881
 882	v9fs_invalidate_inode_attr(dir);
 883	v9inode = V9FS_I(d_inode(dentry));
 884	mutex_lock(&v9inode->v_mutex);
 885	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
 886	    !v9inode->writeback_fid &&
 887	    ((flags & O_ACCMODE) != O_RDONLY)) {
 888		/*
 889		 * clone a fid and add it to writeback_fid
 890		 * we do it during open time instead of
 891		 * page dirty time via write_begin/page_mkwrite
 892		 * because we want write after unlink usecase
 893		 * to work.
 894		 */
 895		inode_fid = v9fs_writeback_fid(dentry);
 896		if (IS_ERR(inode_fid)) {
 897			err = PTR_ERR(inode_fid);
 898			mutex_unlock(&v9inode->v_mutex);
 899			goto error;
 900		}
 901		v9inode->writeback_fid = (void *) inode_fid;
 902	}
 903	mutex_unlock(&v9inode->v_mutex);
 904	err = finish_open(file, dentry, generic_file_open, opened);
 905	if (err)
 906		goto error;
 907
 908	file->private_data = fid;
 909	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 910		v9fs_cache_inode_set_cookie(d_inode(dentry), file);
 911
 912	*opened |= FILE_CREATED;
 913out:
 914	dput(res);
 915	return err;
 916
 917error:
 918	if (fid)
 919		p9_client_clunk(fid);
 920	goto out;
 921}
 922
 923/**
 924 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 925 * @i:  inode that is being unlinked
 926 * @d: dentry that is being unlinked
 927 *
 928 */
 929
 930int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 931{
 932	return v9fs_remove(i, d, 0);
 933}
 934
 935/**
 936 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 937 * @i:  inode that is being unlinked
 938 * @d: dentry that is being unlinked
 939 *
 940 */
 941
 942int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 943{
 944	return v9fs_remove(i, d, AT_REMOVEDIR);
 945}
 946
 947/**
 948 * v9fs_vfs_rename - VFS hook to rename an inode
 949 * @old_dir:  old dir inode
 950 * @old_dentry: old dentry
 951 * @new_dir: new dir inode
 952 * @new_dentry: new dentry
 953 *
 954 */
 955
 956int
 957v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 958		struct inode *new_dir, struct dentry *new_dentry)
 
 959{
 960	int retval;
 961	struct inode *old_inode;
 962	struct inode *new_inode;
 963	struct v9fs_session_info *v9ses;
 964	struct p9_fid *oldfid;
 965	struct p9_fid *olddirfid;
 966	struct p9_fid *newdirfid;
 967	struct p9_wstat wstat;
 968
 
 
 
 969	p9_debug(P9_DEBUG_VFS, "\n");
 970	retval = 0;
 971	old_inode = d_inode(old_dentry);
 972	new_inode = d_inode(new_dentry);
 973	v9ses = v9fs_inode2v9ses(old_inode);
 974	oldfid = v9fs_fid_lookup(old_dentry);
 975	if (IS_ERR(oldfid))
 976		return PTR_ERR(oldfid);
 977
 978	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 979	if (IS_ERR(olddirfid)) {
 980		retval = PTR_ERR(olddirfid);
 981		goto done;
 982	}
 983
 984	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 985	if (IS_ERR(newdirfid)) {
 986		retval = PTR_ERR(newdirfid);
 987		goto clunk_olddir;
 988	}
 989
 990	down_write(&v9ses->rename_sem);
 991	if (v9fs_proto_dotl(v9ses)) {
 992		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 993					    newdirfid, new_dentry->d_name.name);
 994		if (retval == -EOPNOTSUPP)
 995			retval = p9_client_rename(oldfid, newdirfid,
 996						  new_dentry->d_name.name);
 997		if (retval != -EOPNOTSUPP)
 998			goto clunk_newdir;
 999	}
1000	if (old_dentry->d_parent != new_dentry->d_parent) {
1001		/*
1002		 * 9P .u can only handle file rename in the same directory
1003		 */
1004
1005		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1006		retval = -EXDEV;
1007		goto clunk_newdir;
1008	}
1009	v9fs_blank_wstat(&wstat);
1010	wstat.muid = v9ses->uname;
1011	wstat.name = (char *) new_dentry->d_name.name;
1012	retval = p9_client_wstat(oldfid, &wstat);
1013
1014clunk_newdir:
1015	if (!retval) {
1016		if (new_inode) {
1017			if (S_ISDIR(new_inode->i_mode))
1018				clear_nlink(new_inode);
1019			else
1020				drop_nlink(new_inode);
1021		}
1022		if (S_ISDIR(old_inode->i_mode)) {
1023			if (!new_inode)
1024				inc_nlink(new_dir);
1025			drop_nlink(old_dir);
1026		}
1027		v9fs_invalidate_inode_attr(old_inode);
1028		v9fs_invalidate_inode_attr(old_dir);
1029		v9fs_invalidate_inode_attr(new_dir);
1030
1031		/* successful rename */
1032		d_move(old_dentry, new_dentry);
1033	}
1034	up_write(&v9ses->rename_sem);
1035	p9_client_clunk(newdirfid);
1036
1037clunk_olddir:
1038	p9_client_clunk(olddirfid);
1039
1040done:
1041	return retval;
1042}
1043
1044/**
1045 * v9fs_vfs_getattr - retrieve file metadata
1046 * @mnt: mount information
1047 * @dentry: file to get attributes on
1048 * @stat: metadata structure to populate
1049 *
1050 */
1051
1052static int
1053v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1054		 struct kstat *stat)
1055{
1056	struct v9fs_session_info *v9ses;
1057	struct p9_fid *fid;
1058	struct p9_wstat *st;
1059
1060	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1061	v9ses = v9fs_dentry2v9ses(dentry);
1062	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1063		generic_fillattr(d_inode(dentry), stat);
1064		return 0;
1065	}
1066	fid = v9fs_fid_lookup(dentry);
1067	if (IS_ERR(fid))
1068		return PTR_ERR(fid);
1069
1070	st = p9_client_stat(fid);
1071	if (IS_ERR(st))
1072		return PTR_ERR(st);
1073
1074	v9fs_stat2inode(st, d_inode(dentry), d_inode(dentry)->i_sb);
1075	generic_fillattr(d_inode(dentry), stat);
1076
1077	p9stat_free(st);
1078	kfree(st);
1079	return 0;
1080}
1081
1082/**
1083 * v9fs_vfs_setattr - set file metadata
1084 * @dentry: file whose metadata to set
1085 * @iattr: metadata assignment structure
1086 *
1087 */
1088
1089static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1090{
1091	int retval;
1092	struct v9fs_session_info *v9ses;
1093	struct p9_fid *fid;
1094	struct p9_wstat wstat;
1095
1096	p9_debug(P9_DEBUG_VFS, "\n");
1097	retval = inode_change_ok(d_inode(dentry), iattr);
1098	if (retval)
1099		return retval;
1100
1101	retval = -EPERM;
1102	v9ses = v9fs_dentry2v9ses(dentry);
1103	fid = v9fs_fid_lookup(dentry);
1104	if(IS_ERR(fid))
1105		return PTR_ERR(fid);
1106
1107	v9fs_blank_wstat(&wstat);
1108	if (iattr->ia_valid & ATTR_MODE)
1109		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1110
1111	if (iattr->ia_valid & ATTR_MTIME)
1112		wstat.mtime = iattr->ia_mtime.tv_sec;
1113
1114	if (iattr->ia_valid & ATTR_ATIME)
1115		wstat.atime = iattr->ia_atime.tv_sec;
1116
1117	if (iattr->ia_valid & ATTR_SIZE)
1118		wstat.length = iattr->ia_size;
1119
1120	if (v9fs_proto_dotu(v9ses)) {
1121		if (iattr->ia_valid & ATTR_UID)
1122			wstat.n_uid = iattr->ia_uid;
1123
1124		if (iattr->ia_valid & ATTR_GID)
1125			wstat.n_gid = iattr->ia_gid;
1126	}
1127
1128	/* Write all dirty data */
1129	if (d_is_reg(dentry))
1130		filemap_write_and_wait(d_inode(dentry)->i_mapping);
1131
1132	retval = p9_client_wstat(fid, &wstat);
1133	if (retval < 0)
1134		return retval;
1135
1136	if ((iattr->ia_valid & ATTR_SIZE) &&
1137	    iattr->ia_size != i_size_read(d_inode(dentry)))
1138		truncate_setsize(d_inode(dentry), iattr->ia_size);
1139
1140	v9fs_invalidate_inode_attr(d_inode(dentry));
1141
1142	setattr_copy(d_inode(dentry), iattr);
1143	mark_inode_dirty(d_inode(dentry));
1144	return 0;
1145}
1146
1147/**
1148 * v9fs_stat2inode - populate an inode structure with mistat info
1149 * @stat: Plan 9 metadata (mistat) structure
1150 * @inode: inode to populate
1151 * @sb: superblock of filesystem
1152 *
1153 */
1154
1155void
1156v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1157	struct super_block *sb)
1158{
1159	umode_t mode;
1160	char ext[32];
1161	char tag_name[14];
1162	unsigned int i_nlink;
1163	struct v9fs_session_info *v9ses = sb->s_fs_info;
1164	struct v9fs_inode *v9inode = V9FS_I(inode);
1165
1166	set_nlink(inode, 1);
1167
1168	inode->i_atime.tv_sec = stat->atime;
1169	inode->i_mtime.tv_sec = stat->mtime;
1170	inode->i_ctime.tv_sec = stat->mtime;
1171
1172	inode->i_uid = v9ses->dfltuid;
1173	inode->i_gid = v9ses->dfltgid;
1174
1175	if (v9fs_proto_dotu(v9ses)) {
1176		inode->i_uid = stat->n_uid;
1177		inode->i_gid = stat->n_gid;
1178	}
1179	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1180		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1181			/*
1182			 * Hadlink support got added later to
1183			 * to the .u extension. So there can be
1184			 * server out there that doesn't support
1185			 * this even with .u extension. So check
1186			 * for non NULL stat->extension
1187			 */
1188			strlcpy(ext, stat->extension, sizeof(ext));
1189			/* HARDLINKCOUNT %u */
1190			sscanf(ext, "%13s %u", tag_name, &i_nlink);
1191			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1192				set_nlink(inode, i_nlink);
1193		}
1194	}
1195	mode = p9mode2perm(v9ses, stat);
1196	mode |= inode->i_mode & ~S_IALLUGO;
1197	inode->i_mode = mode;
1198	i_size_write(inode, stat->length);
1199
1200	/* not real number of blocks, but 512 byte ones ... */
1201	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1202	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1203}
1204
1205/**
1206 * v9fs_qid2ino - convert qid into inode number
1207 * @qid: qid to hash
1208 *
1209 * BUG: potential for inode number collisions?
1210 */
1211
1212ino_t v9fs_qid2ino(struct p9_qid *qid)
1213{
1214	u64 path = qid->path + 2;
1215	ino_t i = 0;
1216
1217	if (sizeof(ino_t) == sizeof(path))
1218		memcpy(&i, &path, sizeof(ino_t));
1219	else
1220		i = (ino_t) (path ^ (path >> 32));
1221
1222	return i;
1223}
1224
1225/**
1226 * v9fs_vfs_get_link - follow a symlink path
1227 * @dentry: dentry for symlink
1228 * @inode: inode for symlink
1229 * @done: delayed call for when we are done with the return value
1230 */
1231
1232static const char *v9fs_vfs_get_link(struct dentry *dentry,
1233				     struct inode *inode,
1234				     struct delayed_call *done)
1235{
1236	struct v9fs_session_info *v9ses;
1237	struct p9_fid *fid;
1238	struct p9_wstat *st;
1239	char *res;
1240
1241	if (!dentry)
1242		return ERR_PTR(-ECHILD);
1243
1244	v9ses = v9fs_dentry2v9ses(dentry);
1245	fid = v9fs_fid_lookup(dentry);
1246	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1247
1248	if (IS_ERR(fid))
1249		return ERR_CAST(fid);
1250
1251	if (!v9fs_proto_dotu(v9ses))
1252		return ERR_PTR(-EBADF);
1253
1254	st = p9_client_stat(fid);
1255	if (IS_ERR(st))
1256		return ERR_CAST(st);
1257
1258	if (!(st->mode & P9_DMSYMLINK)) {
1259		p9stat_free(st);
1260		kfree(st);
1261		return ERR_PTR(-EINVAL);
1262	}
1263	res = st->extension;
1264	st->extension = NULL;
1265	if (strlen(res) >= PATH_MAX)
1266		res[PATH_MAX - 1] = '\0';
1267
1268	p9stat_free(st);
1269	kfree(st);
1270	set_delayed_call(done, kfree_link, res);
1271	return res;
1272}
1273
1274/**
1275 * v9fs_vfs_mkspecial - create a special file
1276 * @dir: inode to create special file in
1277 * @dentry: dentry to create
1278 * @perm: mode to create special file
1279 * @extension: 9p2000.u format extension string representing special file
1280 *
1281 */
1282
1283static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1284	u32 perm, const char *extension)
1285{
1286	struct p9_fid *fid;
1287	struct v9fs_session_info *v9ses;
1288
1289	v9ses = v9fs_inode2v9ses(dir);
1290	if (!v9fs_proto_dotu(v9ses)) {
1291		p9_debug(P9_DEBUG_ERROR, "not extended\n");
1292		return -EPERM;
1293	}
1294
1295	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1296								P9_OREAD);
1297	if (IS_ERR(fid))
1298		return PTR_ERR(fid);
1299
1300	v9fs_invalidate_inode_attr(dir);
1301	p9_client_clunk(fid);
1302	return 0;
1303}
1304
1305/**
1306 * v9fs_vfs_symlink - helper function to create symlinks
1307 * @dir: directory inode containing symlink
1308 * @dentry: dentry for symlink
1309 * @symname: symlink data
1310 *
1311 * See Also: 9P2000.u RFC for more information
1312 *
1313 */
1314
1315static int
1316v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1317{
1318	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1319		 dir->i_ino, dentry, symname);
1320
1321	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1322}
1323
1324#define U32_MAX_DIGITS 10
1325
1326/**
1327 * v9fs_vfs_link - create a hardlink
1328 * @old_dentry: dentry for file to link to
1329 * @dir: inode destination for new link
1330 * @dentry: dentry for link
1331 *
1332 */
1333
1334static int
1335v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1336	      struct dentry *dentry)
1337{
1338	int retval;
1339	char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1340	struct p9_fid *oldfid;
1341
1342	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1343		 dir->i_ino, dentry, old_dentry);
1344
1345	oldfid = v9fs_fid_clone(old_dentry);
1346	if (IS_ERR(oldfid))
1347		return PTR_ERR(oldfid);
1348
1349	sprintf(name, "%d\n", oldfid->fid);
1350	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1351	if (!retval) {
1352		v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1353		v9fs_invalidate_inode_attr(dir);
1354	}
1355	p9_client_clunk(oldfid);
1356	return retval;
1357}
1358
1359/**
1360 * v9fs_vfs_mknod - create a special file
1361 * @dir: inode destination for new link
1362 * @dentry: dentry for file
1363 * @mode: mode for creation
1364 * @rdev: device associated with special file
1365 *
1366 */
1367
1368static int
1369v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1370{
1371	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1372	int retval;
1373	char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1374	u32 perm;
1375
1376	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
1377		 dir->i_ino, dentry, mode,
1378		 MAJOR(rdev), MINOR(rdev));
1379
1380	/* build extension */
1381	if (S_ISBLK(mode))
1382		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1383	else if (S_ISCHR(mode))
1384		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1385	else
1386		*name = 0;
1387
1388	perm = unixmode2p9mode(v9ses, mode);
1389	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1390
1391	return retval;
1392}
1393
1394int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1395{
1396	int umode;
1397	dev_t rdev;
1398	loff_t i_size;
1399	struct p9_wstat *st;
1400	struct v9fs_session_info *v9ses;
1401
1402	v9ses = v9fs_inode2v9ses(inode);
1403	st = p9_client_stat(fid);
1404	if (IS_ERR(st))
1405		return PTR_ERR(st);
1406	/*
1407	 * Don't update inode if the file type is different
1408	 */
1409	umode = p9mode2unixmode(v9ses, st, &rdev);
1410	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1411		goto out;
1412
1413	spin_lock(&inode->i_lock);
1414	/*
1415	 * We don't want to refresh inode->i_size,
1416	 * because we may have cached data
1417	 */
1418	i_size = inode->i_size;
1419	v9fs_stat2inode(st, inode, inode->i_sb);
1420	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1421		inode->i_size = i_size;
1422	spin_unlock(&inode->i_lock);
1423out:
1424	p9stat_free(st);
1425	kfree(st);
1426	return 0;
1427}
1428
1429static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1430	.create = v9fs_vfs_create,
1431	.lookup = v9fs_vfs_lookup,
1432	.atomic_open = v9fs_vfs_atomic_open,
1433	.symlink = v9fs_vfs_symlink,
1434	.link = v9fs_vfs_link,
1435	.unlink = v9fs_vfs_unlink,
1436	.mkdir = v9fs_vfs_mkdir,
1437	.rmdir = v9fs_vfs_rmdir,
1438	.mknod = v9fs_vfs_mknod,
1439	.rename = v9fs_vfs_rename,
1440	.getattr = v9fs_vfs_getattr,
1441	.setattr = v9fs_vfs_setattr,
1442};
1443
1444static const struct inode_operations v9fs_dir_inode_operations = {
1445	.create = v9fs_vfs_create,
1446	.lookup = v9fs_vfs_lookup,
1447	.atomic_open = v9fs_vfs_atomic_open,
1448	.unlink = v9fs_vfs_unlink,
1449	.mkdir = v9fs_vfs_mkdir,
1450	.rmdir = v9fs_vfs_rmdir,
1451	.mknod = v9fs_vfs_mknod,
1452	.rename = v9fs_vfs_rename,
1453	.getattr = v9fs_vfs_getattr,
1454	.setattr = v9fs_vfs_setattr,
1455};
1456
1457static const struct inode_operations v9fs_file_inode_operations = {
1458	.getattr = v9fs_vfs_getattr,
1459	.setattr = v9fs_vfs_setattr,
1460};
1461
1462static const struct inode_operations v9fs_symlink_inode_operations = {
1463	.readlink = generic_readlink,
1464	.get_link = v9fs_vfs_get_link,
1465	.getattr = v9fs_vfs_getattr,
1466	.setattr = v9fs_vfs_setattr,
1467};
1468