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v3.1
   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#include <linux/module.h>
  27#include <linux/errno.h>
  28#include <linux/fs.h>
  29#include <linux/file.h>
  30#include <linux/pagemap.h>
  31#include <linux/stat.h>
  32#include <linux/string.h>
  33#include <linux/inet.h>
  34#include <linux/namei.h>
  35#include <linux/idr.h>
  36#include <linux/sched.h>
  37#include <linux/slab.h>
  38#include <linux/xattr.h>
  39#include <linux/posix_acl.h>
  40#include <net/9p/9p.h>
  41#include <net/9p/client.h>
  42
  43#include "v9fs.h"
  44#include "v9fs_vfs.h"
  45#include "fid.h"
  46#include "cache.h"
  47#include "xattr.h"
  48#include "acl.h"
  49
  50static const struct inode_operations v9fs_dir_inode_operations;
  51static const struct inode_operations v9fs_dir_inode_operations_dotu;
  52static const struct inode_operations v9fs_file_inode_operations;
  53static const struct inode_operations v9fs_symlink_inode_operations;
  54
  55/**
  56 * unixmode2p9mode - convert unix mode bits to plan 9
  57 * @v9ses: v9fs session information
  58 * @mode: mode to convert
  59 *
  60 */
  61
  62static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  63{
  64	int res;
  65	res = mode & 0777;
  66	if (S_ISDIR(mode))
  67		res |= P9_DMDIR;
  68	if (v9fs_proto_dotu(v9ses)) {
  69		if (S_ISLNK(mode))
  70			res |= P9_DMSYMLINK;
  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		if ((mode & P9_DMLINK))
  89			res |= P9_DMLINK;
  90	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  91
 
 
 
  92	return res;
  93}
  94
  95/**
  96 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  97 * @v9ses: v9fs session information
  98 * @stat: p9_wstat from which mode need to be derived
  99 * @rdev: major number, minor number in case of device files.
 100 *
 101 */
 102static int p9mode2unixmode(struct v9fs_session_info *v9ses,
 103			   struct p9_wstat *stat, dev_t *rdev)
 104{
 105	int res;
 106	int mode = stat->mode;
 107
 108	res = mode & S_IALLUGO;
 109	*rdev = 0;
 
 110
 111	if ((mode & P9_DMDIR) == P9_DMDIR)
 112		res |= S_IFDIR;
 113	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 114		res |= S_IFLNK;
 115	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 116		 && (v9ses->nodev == 0))
 117		res |= S_IFSOCK;
 118	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 119		 && (v9ses->nodev == 0))
 120		res |= S_IFIFO;
 121	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 122		 && (v9ses->nodev == 0)) {
 123		char type = 0, ext[32];
 124		int major = -1, minor = -1;
 125
 126		strncpy(ext, stat->extension, sizeof(ext));
 127		sscanf(ext, "%c %u %u", &type, &major, &minor);
 128		switch (type) {
 129		case 'c':
 130			res |= S_IFCHR;
 131			break;
 132		case 'b':
 133			res |= S_IFBLK;
 134			break;
 135		default:
 136			P9_DPRINTK(P9_DEBUG_ERROR,
 137				"Unknown special type %c %s\n", type,
 138				stat->extension);
 139		};
 140		*rdev = MKDEV(major, minor);
 141	} else
 142		res |= S_IFREG;
 143
 144	if (v9fs_proto_dotu(v9ses)) {
 145		if ((mode & P9_DMSETUID) == P9_DMSETUID)
 146			res |= S_ISUID;
 147
 148		if ((mode & P9_DMSETGID) == P9_DMSETGID)
 149			res |= S_ISGID;
 150
 151		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 152			res |= S_ISVTX;
 153	}
 154	return res;
 155}
 156
 157/**
 158 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 159 * @uflags: flags to convert
 160 * @extended: if .u extensions are active
 161 */
 162
 163int v9fs_uflags2omode(int uflags, int extended)
 164{
 165	int ret;
 166
 167	ret = 0;
 168	switch (uflags&3) {
 169	default:
 170	case O_RDONLY:
 171		ret = P9_OREAD;
 172		break;
 173
 174	case O_WRONLY:
 175		ret = P9_OWRITE;
 176		break;
 177
 178	case O_RDWR:
 179		ret = P9_ORDWR;
 180		break;
 181	}
 182
 183	if (uflags & O_TRUNC)
 184		ret |= P9_OTRUNC;
 185
 186	if (extended) {
 187		if (uflags & O_EXCL)
 188			ret |= P9_OEXCL;
 189
 190		if (uflags & O_APPEND)
 191			ret |= P9_OAPPEND;
 192	}
 193
 194	return ret;
 195}
 196
 197/**
 198 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 199 * @wstat: structure to initialize
 200 *
 201 */
 202
 203void
 204v9fs_blank_wstat(struct p9_wstat *wstat)
 205{
 206	wstat->type = ~0;
 207	wstat->dev = ~0;
 208	wstat->qid.type = ~0;
 209	wstat->qid.version = ~0;
 210	*((long long *)&wstat->qid.path) = ~0;
 211	wstat->mode = ~0;
 212	wstat->atime = ~0;
 213	wstat->mtime = ~0;
 214	wstat->length = ~0;
 215	wstat->name = NULL;
 216	wstat->uid = NULL;
 217	wstat->gid = NULL;
 218	wstat->muid = NULL;
 219	wstat->n_uid = ~0;
 220	wstat->n_gid = ~0;
 221	wstat->n_muid = ~0;
 222	wstat->extension = NULL;
 223}
 224
 225/**
 226 * v9fs_alloc_inode - helper function to allocate an inode
 227 *
 228 */
 229struct inode *v9fs_alloc_inode(struct super_block *sb)
 230{
 231	struct v9fs_inode *v9inode;
 232	v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 233							GFP_KERNEL);
 234	if (!v9inode)
 235		return NULL;
 236#ifdef CONFIG_9P_FSCACHE
 237	v9inode->fscache = NULL;
 238	spin_lock_init(&v9inode->fscache_lock);
 239#endif
 240	v9inode->writeback_fid = NULL;
 241	v9inode->cache_validity = 0;
 242	mutex_init(&v9inode->v_mutex);
 243	return &v9inode->vfs_inode;
 244}
 245
 246/**
 247 * v9fs_destroy_inode - destroy an inode
 248 *
 249 */
 250
 251static void v9fs_i_callback(struct rcu_head *head)
 252{
 253	struct inode *inode = container_of(head, struct inode, i_rcu);
 254	INIT_LIST_HEAD(&inode->i_dentry);
 255	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 256}
 257
 258void v9fs_destroy_inode(struct inode *inode)
 259{
 260	call_rcu(&inode->i_rcu, v9fs_i_callback);
 261}
 262
 263int v9fs_init_inode(struct v9fs_session_info *v9ses,
 264		    struct inode *inode, int mode, dev_t rdev)
 265{
 266	int err = 0;
 267
 268	inode_init_owner(inode, NULL, mode);
 269	inode->i_blocks = 0;
 270	inode->i_rdev = rdev;
 271	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 272	inode->i_mapping->a_ops = &v9fs_addr_operations;
 273
 274	switch (mode & S_IFMT) {
 275	case S_IFIFO:
 276	case S_IFBLK:
 277	case S_IFCHR:
 278	case S_IFSOCK:
 279		if (v9fs_proto_dotl(v9ses)) {
 280			inode->i_op = &v9fs_file_inode_operations_dotl;
 281			inode->i_fop = &v9fs_file_operations_dotl;
 282		} else if (v9fs_proto_dotu(v9ses)) {
 283			inode->i_op = &v9fs_file_inode_operations;
 284			inode->i_fop = &v9fs_file_operations;
 285		} else {
 286			P9_DPRINTK(P9_DEBUG_ERROR,
 287				   "special files without extended mode\n");
 288			err = -EINVAL;
 289			goto error;
 290		}
 291		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 292		break;
 293	case S_IFREG:
 294		if (v9fs_proto_dotl(v9ses)) {
 295			inode->i_op = &v9fs_file_inode_operations_dotl;
 296			if (v9ses->cache)
 
 297				inode->i_fop =
 298					&v9fs_cached_file_operations_dotl;
 
 
 299			else
 300				inode->i_fop = &v9fs_file_operations_dotl;
 301		} else {
 302			inode->i_op = &v9fs_file_inode_operations;
 303			if (v9ses->cache)
 304				inode->i_fop = &v9fs_cached_file_operations;
 
 
 
 
 305			else
 306				inode->i_fop = &v9fs_file_operations;
 307		}
 308
 309		break;
 310	case S_IFLNK:
 311		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 312			P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
 313						"legacy protocol.\n");
 314			err = -EINVAL;
 315			goto error;
 316		}
 317
 318		if (v9fs_proto_dotl(v9ses))
 319			inode->i_op = &v9fs_symlink_inode_operations_dotl;
 320		else
 321			inode->i_op = &v9fs_symlink_inode_operations;
 322
 323		break;
 324	case S_IFDIR:
 325		inc_nlink(inode);
 326		if (v9fs_proto_dotl(v9ses))
 327			inode->i_op = &v9fs_dir_inode_operations_dotl;
 328		else if (v9fs_proto_dotu(v9ses))
 329			inode->i_op = &v9fs_dir_inode_operations_dotu;
 330		else
 331			inode->i_op = &v9fs_dir_inode_operations;
 332
 333		if (v9fs_proto_dotl(v9ses))
 334			inode->i_fop = &v9fs_dir_operations_dotl;
 335		else
 336			inode->i_fop = &v9fs_dir_operations;
 337
 338		break;
 339	default:
 340		P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 341			   mode, mode & S_IFMT);
 342		err = -EINVAL;
 343		goto error;
 344	}
 345error:
 346	return err;
 347
 348}
 349
 350/**
 351 * v9fs_get_inode - helper function to setup an inode
 352 * @sb: superblock
 353 * @mode: mode to setup inode with
 354 *
 355 */
 356
 357struct inode *v9fs_get_inode(struct super_block *sb, int mode, dev_t rdev)
 358{
 359	int err;
 360	struct inode *inode;
 361	struct v9fs_session_info *v9ses = sb->s_fs_info;
 362
 363	P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 364
 365	inode = new_inode(sb);
 366	if (!inode) {
 367		P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 
 368		return ERR_PTR(-ENOMEM);
 369	}
 370	err = v9fs_init_inode(v9ses, inode, mode, rdev);
 371	if (err) {
 372		iput(inode);
 373		return ERR_PTR(err);
 374	}
 375	return inode;
 376}
 377
 378/*
 379static struct v9fs_fid*
 380v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 381{
 382	int err;
 383	int nfid;
 384	struct v9fs_fid *ret;
 385	struct v9fs_fcall *fcall;
 386
 387	nfid = v9fs_get_idpool(&v9ses->fidpool);
 388	if (nfid < 0) {
 389		eprintk(KERN_WARNING, "no free fids available\n");
 390		return ERR_PTR(-ENOSPC);
 391	}
 392
 393	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 394		&fcall);
 395
 396	if (err < 0) {
 397		if (fcall && fcall->id == RWALK)
 398			goto clunk_fid;
 399
 400		PRINT_FCALL_ERROR("walk error", fcall);
 401		v9fs_put_idpool(nfid, &v9ses->fidpool);
 402		goto error;
 403	}
 404
 405	kfree(fcall);
 406	fcall = NULL;
 407	ret = v9fs_fid_create(v9ses, nfid);
 408	if (!ret) {
 409		err = -ENOMEM;
 410		goto clunk_fid;
 411	}
 412
 413	err = v9fs_fid_insert(ret, dentry);
 414	if (err < 0) {
 415		v9fs_fid_destroy(ret);
 416		goto clunk_fid;
 417	}
 418
 419	return ret;
 420
 421clunk_fid:
 422	v9fs_t_clunk(v9ses, nfid);
 423
 424error:
 425	kfree(fcall);
 426	return ERR_PTR(err);
 427}
 428*/
 429
 430
 431/**
 432 * v9fs_clear_inode - release an inode
 433 * @inode: inode to release
 434 *
 435 */
 436void v9fs_evict_inode(struct inode *inode)
 437{
 438	struct v9fs_inode *v9inode = V9FS_I(inode);
 439
 440	truncate_inode_pages(inode->i_mapping, 0);
 441	end_writeback(inode);
 442	filemap_fdatawrite(inode->i_mapping);
 443
 444#ifdef CONFIG_9P_FSCACHE
 445	v9fs_cache_inode_put_cookie(inode);
 446#endif
 447	/* clunk the fid stashed in writeback_fid */
 448	if (v9inode->writeback_fid) {
 449		p9_client_clunk(v9inode->writeback_fid);
 450		v9inode->writeback_fid = NULL;
 451	}
 452}
 453
 454static int v9fs_test_inode(struct inode *inode, void *data)
 455{
 456	int umode;
 457	dev_t rdev;
 458	struct v9fs_inode *v9inode = V9FS_I(inode);
 459	struct p9_wstat *st = (struct p9_wstat *)data;
 460	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 461
 462	umode = p9mode2unixmode(v9ses, st, &rdev);
 463	/* don't match inode of different type */
 464	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 465		return 0;
 466
 467	/* compare qid details */
 468	if (memcmp(&v9inode->qid.version,
 469		   &st->qid.version, sizeof(v9inode->qid.version)))
 470		return 0;
 471
 472	if (v9inode->qid.type != st->qid.type)
 473		return 0;
 474	return 1;
 475}
 476
 477static int v9fs_test_new_inode(struct inode *inode, void *data)
 478{
 479	return 0;
 480}
 481
 482static int v9fs_set_inode(struct inode *inode,  void *data)
 483{
 484	struct v9fs_inode *v9inode = V9FS_I(inode);
 485	struct p9_wstat *st = (struct p9_wstat *)data;
 486
 487	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 488	return 0;
 489}
 490
 491static struct inode *v9fs_qid_iget(struct super_block *sb,
 492				   struct p9_qid *qid,
 493				   struct p9_wstat *st,
 494				   int new)
 495{
 496	dev_t rdev;
 497	int retval, umode;
 
 498	unsigned long i_ino;
 499	struct inode *inode;
 500	struct v9fs_session_info *v9ses = sb->s_fs_info;
 501	int (*test)(struct inode *, void *);
 502
 503	if (new)
 504		test = v9fs_test_new_inode;
 505	else
 506		test = v9fs_test_inode;
 507
 508	i_ino = v9fs_qid2ino(qid);
 509	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 510	if (!inode)
 511		return ERR_PTR(-ENOMEM);
 512	if (!(inode->i_state & I_NEW))
 513		return inode;
 514	/*
 515	 * initialize the inode with the stat info
 516	 * FIXME!! we may need support for stale inodes
 517	 * later.
 518	 */
 519	inode->i_ino = i_ino;
 520	umode = p9mode2unixmode(v9ses, st, &rdev);
 521	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 522	if (retval)
 523		goto error;
 524
 525	v9fs_stat2inode(st, inode, sb);
 526#ifdef CONFIG_9P_FSCACHE
 527	v9fs_cache_inode_get_cookie(inode);
 528#endif
 529	unlock_new_inode(inode);
 530	return inode;
 531error:
 532	unlock_new_inode(inode);
 533	iput(inode);
 534	return ERR_PTR(retval);
 535
 536}
 537
 538struct inode *
 539v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 540		    struct super_block *sb, int new)
 541{
 542	struct p9_wstat *st;
 543	struct inode *inode = NULL;
 544
 545	st = p9_client_stat(fid);
 546	if (IS_ERR(st))
 547		return ERR_CAST(st);
 548
 549	inode = v9fs_qid_iget(sb, &st->qid, st, new);
 550	p9stat_free(st);
 551	kfree(st);
 552	return inode;
 553}
 554
 555/**
 556 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 557 * plan 9 AT flag.
 558 * @flags: flags to convert
 559 */
 560static int v9fs_at_to_dotl_flags(int flags)
 561{
 562	int rflags = 0;
 563	if (flags & AT_REMOVEDIR)
 564		rflags |= P9_DOTL_AT_REMOVEDIR;
 565	return rflags;
 566}
 567
 568/**
 569 * v9fs_remove - helper function to remove files and directories
 570 * @dir: directory inode that is being deleted
 571 * @dentry:  dentry that is being deleted
 572 * @rmdir: removing a directory
 573 *
 574 */
 575
 576static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 577{
 578	struct inode *inode;
 579	int retval = -EOPNOTSUPP;
 580	struct p9_fid *v9fid, *dfid;
 581	struct v9fs_session_info *v9ses;
 582
 583	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 584		   dir, dentry, flags);
 585
 586	v9ses = v9fs_inode2v9ses(dir);
 587	inode = dentry->d_inode;
 588	dfid = v9fs_fid_lookup(dentry->d_parent);
 589	if (IS_ERR(dfid)) {
 590		retval = PTR_ERR(dfid);
 591		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 592		return retval;
 593	}
 594	if (v9fs_proto_dotl(v9ses))
 595		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 596					    v9fs_at_to_dotl_flags(flags));
 597	if (retval == -EOPNOTSUPP) {
 598		/* Try the one based on path */
 599		v9fid = v9fs_fid_clone(dentry);
 600		if (IS_ERR(v9fid))
 601			return PTR_ERR(v9fid);
 602		retval = p9_client_remove(v9fid);
 603	}
 604	if (!retval) {
 605		/*
 606		 * directories on unlink should have zero
 607		 * link count
 608		 */
 609		if (flags & AT_REMOVEDIR) {
 610			clear_nlink(inode);
 611			drop_nlink(dir);
 612		} else
 613			drop_nlink(inode);
 614
 615		v9fs_invalidate_inode_attr(inode);
 616		v9fs_invalidate_inode_attr(dir);
 617	}
 618	return retval;
 619}
 620
 621/**
 622 * v9fs_create - Create a file
 623 * @v9ses: session information
 624 * @dir: directory that dentry is being created in
 625 * @dentry:  dentry that is being created
 626 * @extension: 9p2000.u extension string to support devices, etc.
 627 * @perm: create permissions
 628 * @mode: open mode
 629 *
 630 */
 631static struct p9_fid *
 632v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 633		struct dentry *dentry, char *extension, u32 perm, u8 mode)
 634{
 635	int err;
 636	char *name;
 637	struct p9_fid *dfid, *ofid, *fid;
 638	struct inode *inode;
 639
 640	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 641
 642	err = 0;
 643	ofid = NULL;
 644	fid = NULL;
 645	name = (char *) dentry->d_name.name;
 646	dfid = v9fs_fid_lookup(dentry->d_parent);
 647	if (IS_ERR(dfid)) {
 648		err = PTR_ERR(dfid);
 649		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 650		return ERR_PTR(err);
 651	}
 652
 653	/* clone a fid to use for creation */
 654	ofid = p9_client_walk(dfid, 0, NULL, 1);
 655	if (IS_ERR(ofid)) {
 656		err = PTR_ERR(ofid);
 657		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 658		return ERR_PTR(err);
 659	}
 660
 661	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 662	if (err < 0) {
 663		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 664		goto error;
 665	}
 666
 667	/* now walk from the parent so we can get unopened fid */
 668	fid = p9_client_walk(dfid, 1, &name, 1);
 669	if (IS_ERR(fid)) {
 670		err = PTR_ERR(fid);
 671		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 672		fid = NULL;
 673		goto error;
 674	}
 675
 676	/* instantiate inode and assign the unopened fid to the dentry */
 677	inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 678	if (IS_ERR(inode)) {
 679		err = PTR_ERR(inode);
 680		P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
 681		goto error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 682	}
 683	err = v9fs_fid_add(dentry, fid);
 684	if (err < 0)
 685		goto error;
 686	d_instantiate(dentry, inode);
 687	return ofid;
 688error:
 689	if (ofid)
 690		p9_client_clunk(ofid);
 691
 692	if (fid)
 693		p9_client_clunk(fid);
 694
 695	return ERR_PTR(err);
 696}
 697
 698/**
 699 * v9fs_vfs_create - VFS hook to create files
 
 
 
 
 700 * @dir: directory inode that is being created
 701 * @dentry:  dentry that is being deleted
 702 * @mode: create permissions
 703 * @nd: path information
 704 *
 705 */
 706
 707static int
 708v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 709		struct nameidata *nd)
 710{
 711	int err;
 712	u32 perm;
 713	int flags;
 714	struct file *filp;
 715	struct v9fs_inode *v9inode;
 716	struct v9fs_session_info *v9ses;
 717	struct p9_fid *fid, *inode_fid;
 718
 719	err = 0;
 720	fid = NULL;
 721	v9ses = v9fs_inode2v9ses(dir);
 722	perm = unixmode2p9mode(v9ses, mode);
 723	if (nd)
 724		flags = nd->intent.open.flags;
 725	else
 726		flags = O_RDWR;
 727
 728	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 729				v9fs_uflags2omode(flags,
 730						v9fs_proto_dotu(v9ses)));
 731	if (IS_ERR(fid)) {
 732		err = PTR_ERR(fid);
 733		fid = NULL;
 734		goto error;
 735	}
 736
 737	v9fs_invalidate_inode_attr(dir);
 738	/* if we are opening a file, assign the open fid to the file */
 739	if (nd) {
 740		v9inode = V9FS_I(dentry->d_inode);
 741		mutex_lock(&v9inode->v_mutex);
 742		if (v9ses->cache && !v9inode->writeback_fid &&
 743		    ((flags & O_ACCMODE) != O_RDONLY)) {
 744			/*
 745			 * clone a fid and add it to writeback_fid
 746			 * we do it during open time instead of
 747			 * page dirty time via write_begin/page_mkwrite
 748			 * because we want write after unlink usecase
 749			 * to work.
 750			 */
 751			inode_fid = v9fs_writeback_fid(dentry);
 752			if (IS_ERR(inode_fid)) {
 753				err = PTR_ERR(inode_fid);
 754				mutex_unlock(&v9inode->v_mutex);
 755				goto error;
 756			}
 757			v9inode->writeback_fid = (void *) inode_fid;
 758		}
 759		mutex_unlock(&v9inode->v_mutex);
 760		filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
 761		if (IS_ERR(filp)) {
 762			err = PTR_ERR(filp);
 763			goto error;
 764		}
 765
 766		filp->private_data = fid;
 767#ifdef CONFIG_9P_FSCACHE
 768		if (v9ses->cache)
 769			v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
 770#endif
 771	} else
 772		p9_client_clunk(fid);
 773
 774	return 0;
 775
 776error:
 777	if (fid)
 778		p9_client_clunk(fid);
 779
 780	return err;
 781}
 782
 783/**
 784 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 785 * @dir:  inode that is being unlinked
 786 * @dentry: dentry that is being unlinked
 787 * @mode: mode for new directory
 788 *
 789 */
 790
 791static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 792{
 793	int err;
 794	u32 perm;
 795	struct p9_fid *fid;
 796	struct v9fs_session_info *v9ses;
 797
 798	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 799	err = 0;
 800	v9ses = v9fs_inode2v9ses(dir);
 801	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 802	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 803	if (IS_ERR(fid)) {
 804		err = PTR_ERR(fid);
 805		fid = NULL;
 806	} else {
 807		inc_nlink(dir);
 808		v9fs_invalidate_inode_attr(dir);
 809	}
 810
 811	if (fid)
 812		p9_client_clunk(fid);
 813
 814	return err;
 815}
 816
 817/**
 818 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 819 * @dir:  inode that is being walked from
 820 * @dentry: dentry that is being walked to?
 821 * @nameidata: path data
 822 *
 823 */
 824
 825struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 826				      struct nameidata *nameidata)
 827{
 828	struct dentry *res;
 829	struct super_block *sb;
 830	struct v9fs_session_info *v9ses;
 831	struct p9_fid *dfid, *fid;
 832	struct inode *inode;
 833	char *name;
 834	int result = 0;
 835
 836	P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 837		dir, dentry->d_name.name, dentry, nameidata);
 838
 839	if (dentry->d_name.len > NAME_MAX)
 840		return ERR_PTR(-ENAMETOOLONG);
 841
 842	sb = dir->i_sb;
 843	v9ses = v9fs_inode2v9ses(dir);
 844	/* We can walk d_parent because we hold the dir->i_mutex */
 845	dfid = v9fs_fid_lookup(dentry->d_parent);
 846	if (IS_ERR(dfid))
 847		return ERR_CAST(dfid);
 848
 849	name = (char *) dentry->d_name.name;
 850	fid = p9_client_walk(dfid, 1, &name, 1);
 851	if (IS_ERR(fid)) {
 852		result = PTR_ERR(fid);
 853		if (result == -ENOENT) {
 854			inode = NULL;
 855			goto inst_out;
 856		}
 857
 858		return ERR_PTR(result);
 859	}
 860	/*
 861	 * Make sure we don't use a wrong inode due to parallel
 862	 * unlink. For cached mode create calls request for new
 863	 * inode. But with cache disabled, lookup should do this.
 864	 */
 865	if (v9ses->cache)
 866		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 867	else
 868		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 869	if (IS_ERR(inode)) {
 870		result = PTR_ERR(inode);
 871		inode = NULL;
 872		goto error;
 873	}
 874	result = v9fs_fid_add(dentry, fid);
 875	if (result < 0)
 876		goto error_iput;
 877inst_out:
 878	/*
 879	 * If we had a rename on the server and a parallel lookup
 880	 * for the new name, then make sure we instantiate with
 881	 * the new name. ie look up for a/b, while on server somebody
 882	 * moved b under k and client parallely did a lookup for
 883	 * k/b.
 884	 */
 885	res = d_materialise_unique(dentry, inode);
 886	if (!IS_ERR(res))
 887		return res;
 888	result = PTR_ERR(res);
 889error_iput:
 890	iput(inode);
 891error:
 892	p9_client_clunk(fid);
 
 893
 894	return ERR_PTR(result);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 895}
 896
 897/**
 898 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 899 * @i:  inode that is being unlinked
 900 * @d: dentry that is being unlinked
 901 *
 902 */
 903
 904int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 905{
 906	return v9fs_remove(i, d, 0);
 907}
 908
 909/**
 910 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 911 * @i:  inode that is being unlinked
 912 * @d: dentry that is being unlinked
 913 *
 914 */
 915
 916int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 917{
 918	return v9fs_remove(i, d, AT_REMOVEDIR);
 919}
 920
 921/**
 922 * v9fs_vfs_rename - VFS hook to rename an inode
 923 * @old_dir:  old dir inode
 924 * @old_dentry: old dentry
 925 * @new_dir: new dir inode
 926 * @new_dentry: new dentry
 927 *
 928 */
 929
 930int
 931v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 932		struct inode *new_dir, struct dentry *new_dentry)
 933{
 934	int retval;
 935	struct inode *old_inode;
 936	struct inode *new_inode;
 937	struct v9fs_session_info *v9ses;
 938	struct p9_fid *oldfid;
 939	struct p9_fid *olddirfid;
 940	struct p9_fid *newdirfid;
 941	struct p9_wstat wstat;
 942
 943	P9_DPRINTK(P9_DEBUG_VFS, "\n");
 944	retval = 0;
 945	old_inode = old_dentry->d_inode;
 946	new_inode = new_dentry->d_inode;
 947	v9ses = v9fs_inode2v9ses(old_inode);
 948	oldfid = v9fs_fid_lookup(old_dentry);
 949	if (IS_ERR(oldfid))
 950		return PTR_ERR(oldfid);
 951
 952	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 953	if (IS_ERR(olddirfid)) {
 954		retval = PTR_ERR(olddirfid);
 955		goto done;
 956	}
 957
 958	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 959	if (IS_ERR(newdirfid)) {
 960		retval = PTR_ERR(newdirfid);
 961		goto clunk_olddir;
 962	}
 963
 964	down_write(&v9ses->rename_sem);
 965	if (v9fs_proto_dotl(v9ses)) {
 966		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 967					    newdirfid, new_dentry->d_name.name);
 968		if (retval == -EOPNOTSUPP)
 969			retval = p9_client_rename(oldfid, newdirfid,
 970						  new_dentry->d_name.name);
 971		if (retval != -EOPNOTSUPP)
 972			goto clunk_newdir;
 973	}
 974	if (old_dentry->d_parent != new_dentry->d_parent) {
 975		/*
 976		 * 9P .u can only handle file rename in the same directory
 977		 */
 978
 979		P9_DPRINTK(P9_DEBUG_ERROR,
 980				"old dir and new dir are different\n");
 981		retval = -EXDEV;
 982		goto clunk_newdir;
 983	}
 984	v9fs_blank_wstat(&wstat);
 985	wstat.muid = v9ses->uname;
 986	wstat.name = (char *) new_dentry->d_name.name;
 987	retval = p9_client_wstat(oldfid, &wstat);
 988
 989clunk_newdir:
 990	if (!retval) {
 991		if (new_inode) {
 992			if (S_ISDIR(new_inode->i_mode))
 993				clear_nlink(new_inode);
 994			else
 995				drop_nlink(new_inode);
 996		}
 997		if (S_ISDIR(old_inode->i_mode)) {
 998			if (!new_inode)
 999				inc_nlink(new_dir);
1000			drop_nlink(old_dir);
1001		}
1002		v9fs_invalidate_inode_attr(old_inode);
1003		v9fs_invalidate_inode_attr(old_dir);
1004		v9fs_invalidate_inode_attr(new_dir);
1005
1006		/* successful rename */
1007		d_move(old_dentry, new_dentry);
1008	}
1009	up_write(&v9ses->rename_sem);
1010	p9_client_clunk(newdirfid);
1011
1012clunk_olddir:
1013	p9_client_clunk(olddirfid);
1014
1015done:
1016	return retval;
1017}
1018
1019/**
1020 * v9fs_vfs_getattr - retrieve file metadata
1021 * @mnt: mount information
1022 * @dentry: file to get attributes on
1023 * @stat: metadata structure to populate
1024 *
1025 */
1026
1027static int
1028v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1029		 struct kstat *stat)
1030{
1031	int err;
1032	struct v9fs_session_info *v9ses;
1033	struct p9_fid *fid;
1034	struct p9_wstat *st;
1035
1036	P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1037	err = -EPERM;
1038	v9ses = v9fs_dentry2v9ses(dentry);
1039	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1040		generic_fillattr(dentry->d_inode, stat);
1041		return 0;
1042	}
1043	fid = v9fs_fid_lookup(dentry);
1044	if (IS_ERR(fid))
1045		return PTR_ERR(fid);
1046
1047	st = p9_client_stat(fid);
1048	if (IS_ERR(st))
1049		return PTR_ERR(st);
1050
1051	v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1052	generic_fillattr(dentry->d_inode, stat);
1053
1054	p9stat_free(st);
1055	kfree(st);
1056	return 0;
1057}
1058
1059/**
1060 * v9fs_vfs_setattr - set file metadata
1061 * @dentry: file whose metadata to set
1062 * @iattr: metadata assignment structure
1063 *
1064 */
1065
1066static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1067{
1068	int retval;
1069	struct v9fs_session_info *v9ses;
1070	struct p9_fid *fid;
1071	struct p9_wstat wstat;
1072
1073	P9_DPRINTK(P9_DEBUG_VFS, "\n");
1074	retval = inode_change_ok(dentry->d_inode, iattr);
1075	if (retval)
1076		return retval;
1077
1078	retval = -EPERM;
1079	v9ses = v9fs_dentry2v9ses(dentry);
1080	fid = v9fs_fid_lookup(dentry);
1081	if(IS_ERR(fid))
1082		return PTR_ERR(fid);
1083
1084	v9fs_blank_wstat(&wstat);
1085	if (iattr->ia_valid & ATTR_MODE)
1086		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1087
1088	if (iattr->ia_valid & ATTR_MTIME)
1089		wstat.mtime = iattr->ia_mtime.tv_sec;
1090
1091	if (iattr->ia_valid & ATTR_ATIME)
1092		wstat.atime = iattr->ia_atime.tv_sec;
1093
1094	if (iattr->ia_valid & ATTR_SIZE)
1095		wstat.length = iattr->ia_size;
1096
1097	if (v9fs_proto_dotu(v9ses)) {
1098		if (iattr->ia_valid & ATTR_UID)
1099			wstat.n_uid = iattr->ia_uid;
1100
1101		if (iattr->ia_valid & ATTR_GID)
1102			wstat.n_gid = iattr->ia_gid;
1103	}
1104
1105	/* Write all dirty data */
1106	if (S_ISREG(dentry->d_inode->i_mode))
1107		filemap_write_and_wait(dentry->d_inode->i_mapping);
1108
1109	retval = p9_client_wstat(fid, &wstat);
1110	if (retval < 0)
1111		return retval;
1112
1113	if ((iattr->ia_valid & ATTR_SIZE) &&
1114	    iattr->ia_size != i_size_read(dentry->d_inode))
1115		truncate_setsize(dentry->d_inode, iattr->ia_size);
1116
1117	v9fs_invalidate_inode_attr(dentry->d_inode);
1118
1119	setattr_copy(dentry->d_inode, iattr);
1120	mark_inode_dirty(dentry->d_inode);
1121	return 0;
1122}
1123
1124/**
1125 * v9fs_stat2inode - populate an inode structure with mistat info
1126 * @stat: Plan 9 metadata (mistat) structure
1127 * @inode: inode to populate
1128 * @sb: superblock of filesystem
1129 *
1130 */
1131
1132void
1133v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1134	struct super_block *sb)
1135{
1136	mode_t mode;
1137	char ext[32];
1138	char tag_name[14];
1139	unsigned int i_nlink;
1140	struct v9fs_session_info *v9ses = sb->s_fs_info;
1141	struct v9fs_inode *v9inode = V9FS_I(inode);
1142
1143	inode->i_nlink = 1;
1144
1145	inode->i_atime.tv_sec = stat->atime;
1146	inode->i_mtime.tv_sec = stat->mtime;
1147	inode->i_ctime.tv_sec = stat->mtime;
1148
1149	inode->i_uid = v9ses->dfltuid;
1150	inode->i_gid = v9ses->dfltgid;
1151
1152	if (v9fs_proto_dotu(v9ses)) {
1153		inode->i_uid = stat->n_uid;
1154		inode->i_gid = stat->n_gid;
1155	}
1156	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1157		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1158			/*
1159			 * Hadlink support got added later to
1160			 * to the .u extension. So there can be
1161			 * server out there that doesn't support
1162			 * this even with .u extension. So check
1163			 * for non NULL stat->extension
1164			 */
1165			strncpy(ext, stat->extension, sizeof(ext));
1166			/* HARDLINKCOUNT %u */
1167			sscanf(ext, "%13s %u", tag_name, &i_nlink);
1168			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1169				inode->i_nlink = i_nlink;
1170		}
1171	}
1172	mode = stat->mode & S_IALLUGO;
1173	mode |= inode->i_mode & ~S_IALLUGO;
1174	inode->i_mode = mode;
1175	i_size_write(inode, stat->length);
1176
1177	/* not real number of blocks, but 512 byte ones ... */
1178	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1179	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1180}
1181
1182/**
1183 * v9fs_qid2ino - convert qid into inode number
1184 * @qid: qid to hash
1185 *
1186 * BUG: potential for inode number collisions?
1187 */
1188
1189ino_t v9fs_qid2ino(struct p9_qid *qid)
1190{
1191	u64 path = qid->path + 2;
1192	ino_t i = 0;
1193
1194	if (sizeof(ino_t) == sizeof(path))
1195		memcpy(&i, &path, sizeof(ino_t));
1196	else
1197		i = (ino_t) (path ^ (path >> 32));
1198
1199	return i;
1200}
1201
1202/**
1203 * v9fs_readlink - read a symlink's location (internal version)
1204 * @dentry: dentry for symlink
1205 * @buffer: buffer to load symlink location into
1206 * @buflen: length of buffer
1207 *
1208 */
1209
1210static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1211{
1212	int retval;
1213
1214	struct v9fs_session_info *v9ses;
1215	struct p9_fid *fid;
1216	struct p9_wstat *st;
1217
1218	P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1219	retval = -EPERM;
1220	v9ses = v9fs_dentry2v9ses(dentry);
1221	fid = v9fs_fid_lookup(dentry);
1222	if (IS_ERR(fid))
1223		return PTR_ERR(fid);
1224
1225	if (!v9fs_proto_dotu(v9ses))
1226		return -EBADF;
1227
1228	st = p9_client_stat(fid);
1229	if (IS_ERR(st))
1230		return PTR_ERR(st);
1231
1232	if (!(st->mode & P9_DMSYMLINK)) {
1233		retval = -EINVAL;
1234		goto done;
1235	}
1236
1237	/* copy extension buffer into buffer */
1238	strncpy(buffer, st->extension, buflen);
 
1239
1240	P9_DPRINTK(P9_DEBUG_VFS,
1241		"%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
1242
1243	retval = strnlen(buffer, buflen);
1244done:
1245	p9stat_free(st);
1246	kfree(st);
1247	return retval;
1248}
1249
1250/**
1251 * v9fs_vfs_follow_link - follow a symlink path
1252 * @dentry: dentry for symlink
1253 * @nd: nameidata
1254 *
1255 */
1256
1257static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1258{
1259	int len = 0;
1260	char *link = __getname();
1261
1262	P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
1263
1264	if (!link)
1265		link = ERR_PTR(-ENOMEM);
1266	else {
1267		len = v9fs_readlink(dentry, link, PATH_MAX);
1268
1269		if (len < 0) {
1270			__putname(link);
1271			link = ERR_PTR(len);
1272		} else
1273			link[min(len, PATH_MAX-1)] = 0;
1274	}
1275	nd_set_link(nd, link);
1276
1277	return NULL;
1278}
1279
1280/**
1281 * v9fs_vfs_put_link - release a symlink path
1282 * @dentry: dentry for symlink
1283 * @nd: nameidata
1284 * @p: unused
1285 *
1286 */
1287
1288void
1289v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1290{
1291	char *s = nd_get_link(nd);
1292
1293	P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
1294		IS_ERR(s) ? "<error>" : s);
1295	if (!IS_ERR(s))
1296		__putname(s);
1297}
1298
1299/**
1300 * v9fs_vfs_mkspecial - create a special file
1301 * @dir: inode to create special file in
1302 * @dentry: dentry to create
1303 * @mode: mode to create special file
1304 * @extension: 9p2000.u format extension string representing special file
1305 *
1306 */
1307
1308static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1309	int mode, const char *extension)
1310{
1311	u32 perm;
1312	struct p9_fid *fid;
1313	struct v9fs_session_info *v9ses;
1314
1315	v9ses = v9fs_inode2v9ses(dir);
1316	if (!v9fs_proto_dotu(v9ses)) {
1317		P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1318		return -EPERM;
1319	}
1320
1321	perm = unixmode2p9mode(v9ses, mode);
1322	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1323								P9_OREAD);
1324	if (IS_ERR(fid))
1325		return PTR_ERR(fid);
1326
1327	v9fs_invalidate_inode_attr(dir);
1328	p9_client_clunk(fid);
1329	return 0;
1330}
1331
1332/**
1333 * v9fs_vfs_symlink - helper function to create symlinks
1334 * @dir: directory inode containing symlink
1335 * @dentry: dentry for symlink
1336 * @symname: symlink data
1337 *
1338 * See Also: 9P2000.u RFC for more information
1339 *
1340 */
1341
1342static int
1343v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1344{
1345	P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1346					dentry->d_name.name, symname);
1347
1348	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1349}
1350
1351/**
1352 * v9fs_vfs_link - create a hardlink
1353 * @old_dentry: dentry for file to link to
1354 * @dir: inode destination for new link
1355 * @dentry: dentry for link
1356 *
1357 */
1358
1359static int
1360v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1361	      struct dentry *dentry)
1362{
1363	int retval;
1364	char *name;
1365	struct p9_fid *oldfid;
1366
1367	P9_DPRINTK(P9_DEBUG_VFS,
1368		" %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1369		old_dentry->d_name.name);
1370
1371	oldfid = v9fs_fid_clone(old_dentry);
1372	if (IS_ERR(oldfid))
1373		return PTR_ERR(oldfid);
1374
1375	name = __getname();
1376	if (unlikely(!name)) {
1377		retval = -ENOMEM;
1378		goto clunk_fid;
1379	}
1380
1381	sprintf(name, "%d\n", oldfid->fid);
1382	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1383	__putname(name);
1384	if (!retval) {
1385		v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1386		v9fs_invalidate_inode_attr(dir);
1387	}
1388clunk_fid:
1389	p9_client_clunk(oldfid);
1390	return retval;
1391}
1392
1393/**
1394 * v9fs_vfs_mknod - create a special file
1395 * @dir: inode destination for new link
1396 * @dentry: dentry for file
1397 * @mode: mode for creation
1398 * @rdev: device associated with special file
1399 *
1400 */
1401
1402static int
1403v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1404{
 
1405	int retval;
1406	char *name;
 
1407
1408	P9_DPRINTK(P9_DEBUG_VFS,
1409		" %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1410		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1411
1412	if (!new_valid_dev(rdev))
1413		return -EINVAL;
1414
1415	name = __getname();
1416	if (!name)
1417		return -ENOMEM;
1418	/* build extension */
1419	if (S_ISBLK(mode))
1420		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1421	else if (S_ISCHR(mode))
1422		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1423	else if (S_ISFIFO(mode))
1424		*name = 0;
1425	else if (S_ISSOCK(mode))
1426		*name = 0;
1427	else {
1428		__putname(name);
1429		return -EINVAL;
1430	}
1431
1432	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
 
1433	__putname(name);
1434
1435	return retval;
1436}
1437
1438int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1439{
1440	int umode;
1441	dev_t rdev;
1442	loff_t i_size;
1443	struct p9_wstat *st;
1444	struct v9fs_session_info *v9ses;
1445
1446	v9ses = v9fs_inode2v9ses(inode);
1447	st = p9_client_stat(fid);
1448	if (IS_ERR(st))
1449		return PTR_ERR(st);
1450	/*
1451	 * Don't update inode if the file type is different
1452	 */
1453	umode = p9mode2unixmode(v9ses, st, &rdev);
1454	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1455		goto out;
1456
1457	spin_lock(&inode->i_lock);
1458	/*
1459	 * We don't want to refresh inode->i_size,
1460	 * because we may have cached data
1461	 */
1462	i_size = inode->i_size;
1463	v9fs_stat2inode(st, inode, inode->i_sb);
1464	if (v9ses->cache)
1465		inode->i_size = i_size;
1466	spin_unlock(&inode->i_lock);
1467out:
1468	p9stat_free(st);
1469	kfree(st);
1470	return 0;
1471}
1472
1473static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1474	.create = v9fs_vfs_create,
1475	.lookup = v9fs_vfs_lookup,
 
1476	.symlink = v9fs_vfs_symlink,
1477	.link = v9fs_vfs_link,
1478	.unlink = v9fs_vfs_unlink,
1479	.mkdir = v9fs_vfs_mkdir,
1480	.rmdir = v9fs_vfs_rmdir,
1481	.mknod = v9fs_vfs_mknod,
1482	.rename = v9fs_vfs_rename,
1483	.getattr = v9fs_vfs_getattr,
1484	.setattr = v9fs_vfs_setattr,
1485};
1486
1487static const struct inode_operations v9fs_dir_inode_operations = {
1488	.create = v9fs_vfs_create,
1489	.lookup = v9fs_vfs_lookup,
 
1490	.unlink = v9fs_vfs_unlink,
1491	.mkdir = v9fs_vfs_mkdir,
1492	.rmdir = v9fs_vfs_rmdir,
1493	.mknod = v9fs_vfs_mknod,
1494	.rename = v9fs_vfs_rename,
1495	.getattr = v9fs_vfs_getattr,
1496	.setattr = v9fs_vfs_setattr,
1497};
1498
1499static const struct inode_operations v9fs_file_inode_operations = {
1500	.getattr = v9fs_vfs_getattr,
1501	.setattr = v9fs_vfs_setattr,
1502};
1503
1504static const struct inode_operations v9fs_symlink_inode_operations = {
1505	.readlink = generic_readlink,
1506	.follow_link = v9fs_vfs_follow_link,
1507	.put_link = v9fs_vfs_put_link,
1508	.getattr = v9fs_vfs_getattr,
1509	.setattr = v9fs_vfs_setattr,
1510};
1511
v3.15
   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 %u %u", &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	spin_lock_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_mapping);
 455	clear_inode(inode);
 456	filemap_fdatawrite(inode->i_mapping);
 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	unlock_new_inode(inode);
 544	iput(inode);
 545	return ERR_PTR(retval);
 546
 547}
 548
 549struct inode *
 550v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 551		    struct super_block *sb, int new)
 552{
 553	struct p9_wstat *st;
 554	struct inode *inode = NULL;
 555
 556	st = p9_client_stat(fid);
 557	if (IS_ERR(st))
 558		return ERR_CAST(st);
 559
 560	inode = v9fs_qid_iget(sb, &st->qid, st, new);
 561	p9stat_free(st);
 562	kfree(st);
 563	return inode;
 564}
 565
 566/**
 567 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 568 * plan 9 AT flag.
 569 * @flags: flags to convert
 570 */
 571static int v9fs_at_to_dotl_flags(int flags)
 572{
 573	int rflags = 0;
 574	if (flags & AT_REMOVEDIR)
 575		rflags |= P9_DOTL_AT_REMOVEDIR;
 576	return rflags;
 577}
 578
 579/**
 580 * v9fs_remove - helper function to remove files and directories
 581 * @dir: directory inode that is being deleted
 582 * @dentry:  dentry that is being deleted
 583 * @rmdir: removing a directory
 584 *
 585 */
 586
 587static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 588{
 589	struct inode *inode;
 590	int retval = -EOPNOTSUPP;
 591	struct p9_fid *v9fid, *dfid;
 592	struct v9fs_session_info *v9ses;
 593
 594	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 595		 dir, dentry, flags);
 596
 597	v9ses = v9fs_inode2v9ses(dir);
 598	inode = dentry->d_inode;
 599	dfid = v9fs_fid_lookup(dentry->d_parent);
 600	if (IS_ERR(dfid)) {
 601		retval = PTR_ERR(dfid);
 602		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 603		return retval;
 604	}
 605	if (v9fs_proto_dotl(v9ses))
 606		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 607					    v9fs_at_to_dotl_flags(flags));
 608	if (retval == -EOPNOTSUPP) {
 609		/* Try the one based on path */
 610		v9fid = v9fs_fid_clone(dentry);
 611		if (IS_ERR(v9fid))
 612			return PTR_ERR(v9fid);
 613		retval = p9_client_remove(v9fid);
 614	}
 615	if (!retval) {
 616		/*
 617		 * directories on unlink should have zero
 618		 * link count
 619		 */
 620		if (flags & AT_REMOVEDIR) {
 621			clear_nlink(inode);
 622			drop_nlink(dir);
 623		} else
 624			drop_nlink(inode);
 625
 626		v9fs_invalidate_inode_attr(inode);
 627		v9fs_invalidate_inode_attr(dir);
 628	}
 629	return retval;
 630}
 631
 632/**
 633 * v9fs_create - Create a file
 634 * @v9ses: session information
 635 * @dir: directory that dentry is being created in
 636 * @dentry:  dentry that is being created
 637 * @extension: 9p2000.u extension string to support devices, etc.
 638 * @perm: create permissions
 639 * @mode: open mode
 640 *
 641 */
 642static struct p9_fid *
 643v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 644		struct dentry *dentry, char *extension, u32 perm, u8 mode)
 645{
 646	int err;
 647	char *name;
 648	struct p9_fid *dfid, *ofid, *fid;
 649	struct inode *inode;
 650
 651	p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 652
 653	err = 0;
 654	ofid = NULL;
 655	fid = NULL;
 656	name = (char *) dentry->d_name.name;
 657	dfid = v9fs_fid_lookup(dentry->d_parent);
 658	if (IS_ERR(dfid)) {
 659		err = PTR_ERR(dfid);
 660		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 661		return ERR_PTR(err);
 662	}
 663
 664	/* clone a fid to use for creation */
 665	ofid = p9_client_walk(dfid, 0, NULL, 1);
 666	if (IS_ERR(ofid)) {
 667		err = PTR_ERR(ofid);
 668		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 669		return ERR_PTR(err);
 670	}
 671
 672	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 673	if (err < 0) {
 674		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 
 
 
 
 
 
 
 
 
 675		goto error;
 676	}
 677
 678	if (!(perm & P9_DMLINK)) {
 679		/* now walk from the parent so we can get unopened fid */
 680		fid = p9_client_walk(dfid, 1, &name, 1);
 681		if (IS_ERR(fid)) {
 682			err = PTR_ERR(fid);
 683			p9_debug(P9_DEBUG_VFS,
 684				   "p9_client_walk failed %d\n", err);
 685			fid = NULL;
 686			goto error;
 687		}
 688		/*
 689		 * instantiate inode and assign the unopened fid to the dentry
 690		 */
 691		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 692		if (IS_ERR(inode)) {
 693			err = PTR_ERR(inode);
 694			p9_debug(P9_DEBUG_VFS,
 695				   "inode creation failed %d\n", err);
 696			goto error;
 697		}
 698		v9fs_fid_add(dentry, fid);
 699		d_instantiate(dentry, inode);
 700	}
 
 
 
 
 701	return ofid;
 702error:
 703	if (ofid)
 704		p9_client_clunk(ofid);
 705
 706	if (fid)
 707		p9_client_clunk(fid);
 708
 709	return ERR_PTR(err);
 710}
 711
 712/**
 713 * v9fs_vfs_create - VFS hook to create a regular file
 714 *
 715 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 716 * for mknod(2).
 717 *
 718 * @dir: directory inode that is being created
 719 * @dentry:  dentry that is being deleted
 720 * @mode: create permissions
 
 721 *
 722 */
 723
 724static int
 725v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 726		bool excl)
 727{
 728	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 729	u32 perm = unixmode2p9mode(v9ses, mode);
 730	struct p9_fid *fid;
 
 
 
 
 
 
 
 
 
 
 
 
 
 731
 732	/* P9_OEXCL? */
 733	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 734	if (IS_ERR(fid))
 735		return PTR_ERR(fid);
 
 
 
 
 736
 737	v9fs_invalidate_inode_attr(dir);
 738	p9_client_clunk(fid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 739
 740	return 0;
 
 
 
 
 
 
 741}
 742
 743/**
 744 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 745 * @dir:  inode that is being unlinked
 746 * @dentry: dentry that is being unlinked
 747 * @mode: mode for new directory
 748 *
 749 */
 750
 751static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 752{
 753	int err;
 754	u32 perm;
 755	struct p9_fid *fid;
 756	struct v9fs_session_info *v9ses;
 757
 758	p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 759	err = 0;
 760	v9ses = v9fs_inode2v9ses(dir);
 761	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 762	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 763	if (IS_ERR(fid)) {
 764		err = PTR_ERR(fid);
 765		fid = NULL;
 766	} else {
 767		inc_nlink(dir);
 768		v9fs_invalidate_inode_attr(dir);
 769	}
 770
 771	if (fid)
 772		p9_client_clunk(fid);
 773
 774	return err;
 775}
 776
 777/**
 778 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 779 * @dir:  inode that is being walked from
 780 * @dentry: dentry that is being walked to?
 781 * @nameidata: path data
 782 *
 783 */
 784
 785struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 786				      unsigned int flags)
 787{
 788	struct dentry *res;
 
 789	struct v9fs_session_info *v9ses;
 790	struct p9_fid *dfid, *fid;
 791	struct inode *inode;
 792	char *name;
 
 793
 794	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p flags: %x\n",
 795		 dir, dentry->d_name.name, dentry, flags);
 796
 797	if (dentry->d_name.len > NAME_MAX)
 798		return ERR_PTR(-ENAMETOOLONG);
 799
 
 800	v9ses = v9fs_inode2v9ses(dir);
 801	/* We can walk d_parent because we hold the dir->i_mutex */
 802	dfid = v9fs_fid_lookup(dentry->d_parent);
 803	if (IS_ERR(dfid))
 804		return ERR_CAST(dfid);
 805
 806	name = (char *) dentry->d_name.name;
 807	fid = p9_client_walk(dfid, 1, &name, 1);
 808	if (IS_ERR(fid)) {
 809		if (fid == ERR_PTR(-ENOENT)) {
 810			d_add(dentry, NULL);
 811			return NULL;
 
 812		}
 813		return ERR_CAST(fid);
 
 814	}
 815	/*
 816	 * Make sure we don't use a wrong inode due to parallel
 817	 * unlink. For cached mode create calls request for new
 818	 * inode. But with cache disabled, lookup should do this.
 819	 */
 820	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 821		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 822	else
 823		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 824	if (IS_ERR(inode)) {
 825		p9_client_clunk(fid);
 826		return ERR_CAST(inode);
 
 827	}
 
 
 
 
 828	/*
 829	 * If we had a rename on the server and a parallel lookup
 830	 * for the new name, then make sure we instantiate with
 831	 * the new name. ie look up for a/b, while on server somebody
 832	 * moved b under k and client parallely did a lookup for
 833	 * k/b.
 834	 */
 835	res = d_materialise_unique(dentry, inode);
 836	if (!res)
 837		v9fs_fid_add(dentry, fid);
 838	else if (!IS_ERR(res))
 839		v9fs_fid_add(res, fid);
 840	else
 841		p9_client_clunk(fid);
 842	return res;
 843}
 844
 845static int
 846v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 847		     struct file *file, unsigned flags, umode_t mode,
 848		     int *opened)
 849{
 850	int err;
 851	u32 perm;
 852	struct v9fs_inode *v9inode;
 853	struct v9fs_session_info *v9ses;
 854	struct p9_fid *fid, *inode_fid;
 855	struct dentry *res = NULL;
 856
 857	if (d_unhashed(dentry)) {
 858		res = v9fs_vfs_lookup(dir, dentry, 0);
 859		if (IS_ERR(res))
 860			return PTR_ERR(res);
 861
 862		if (res)
 863			dentry = res;
 864	}
 865
 866	/* Only creates */
 867	if (!(flags & O_CREAT) || dentry->d_inode)
 868		return finish_no_open(file, res);
 869
 870	err = 0;
 871
 872	v9ses = v9fs_inode2v9ses(dir);
 873	perm = unixmode2p9mode(v9ses, mode);
 874	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 875				v9fs_uflags2omode(flags,
 876						v9fs_proto_dotu(v9ses)));
 877	if (IS_ERR(fid)) {
 878		err = PTR_ERR(fid);
 879		fid = NULL;
 880		goto error;
 881	}
 882
 883	v9fs_invalidate_inode_attr(dir);
 884	v9inode = V9FS_I(dentry->d_inode);
 885	mutex_lock(&v9inode->v_mutex);
 886	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
 887	    !v9inode->writeback_fid &&
 888	    ((flags & O_ACCMODE) != O_RDONLY)) {
 889		/*
 890		 * clone a fid and add it to writeback_fid
 891		 * we do it during open time instead of
 892		 * page dirty time via write_begin/page_mkwrite
 893		 * because we want write after unlink usecase
 894		 * to work.
 895		 */
 896		inode_fid = v9fs_writeback_fid(dentry);
 897		if (IS_ERR(inode_fid)) {
 898			err = PTR_ERR(inode_fid);
 899			mutex_unlock(&v9inode->v_mutex);
 900			goto error;
 901		}
 902		v9inode->writeback_fid = (void *) inode_fid;
 903	}
 904	mutex_unlock(&v9inode->v_mutex);
 905	err = finish_open(file, dentry, generic_file_open, opened);
 906	if (err)
 907		goto error;
 908
 909	file->private_data = fid;
 910	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 911		v9fs_cache_inode_set_cookie(dentry->d_inode, file);
 912
 913	*opened |= FILE_CREATED;
 914out:
 915	dput(res);
 916	return err;
 917
 918error:
 919	if (fid)
 920		p9_client_clunk(fid);
 921	goto out;
 922}
 923
 924/**
 925 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 926 * @i:  inode that is being unlinked
 927 * @d: dentry that is being unlinked
 928 *
 929 */
 930
 931int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 932{
 933	return v9fs_remove(i, d, 0);
 934}
 935
 936/**
 937 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 938 * @i:  inode that is being unlinked
 939 * @d: dentry that is being unlinked
 940 *
 941 */
 942
 943int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 944{
 945	return v9fs_remove(i, d, AT_REMOVEDIR);
 946}
 947
 948/**
 949 * v9fs_vfs_rename - VFS hook to rename an inode
 950 * @old_dir:  old dir inode
 951 * @old_dentry: old dentry
 952 * @new_dir: new dir inode
 953 * @new_dentry: new dentry
 954 *
 955 */
 956
 957int
 958v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 959		struct inode *new_dir, struct dentry *new_dentry)
 960{
 961	int retval;
 962	struct inode *old_inode;
 963	struct inode *new_inode;
 964	struct v9fs_session_info *v9ses;
 965	struct p9_fid *oldfid;
 966	struct p9_fid *olddirfid;
 967	struct p9_fid *newdirfid;
 968	struct p9_wstat wstat;
 969
 970	p9_debug(P9_DEBUG_VFS, "\n");
 971	retval = 0;
 972	old_inode = old_dentry->d_inode;
 973	new_inode = new_dentry->d_inode;
 974	v9ses = v9fs_inode2v9ses(old_inode);
 975	oldfid = v9fs_fid_lookup(old_dentry);
 976	if (IS_ERR(oldfid))
 977		return PTR_ERR(oldfid);
 978
 979	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 980	if (IS_ERR(olddirfid)) {
 981		retval = PTR_ERR(olddirfid);
 982		goto done;
 983	}
 984
 985	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 986	if (IS_ERR(newdirfid)) {
 987		retval = PTR_ERR(newdirfid);
 988		goto clunk_olddir;
 989	}
 990
 991	down_write(&v9ses->rename_sem);
 992	if (v9fs_proto_dotl(v9ses)) {
 993		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 994					    newdirfid, new_dentry->d_name.name);
 995		if (retval == -EOPNOTSUPP)
 996			retval = p9_client_rename(oldfid, newdirfid,
 997						  new_dentry->d_name.name);
 998		if (retval != -EOPNOTSUPP)
 999			goto clunk_newdir;
1000	}
1001	if (old_dentry->d_parent != new_dentry->d_parent) {
1002		/*
1003		 * 9P .u can only handle file rename in the same directory
1004		 */
1005
1006		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 
1007		retval = -EXDEV;
1008		goto clunk_newdir;
1009	}
1010	v9fs_blank_wstat(&wstat);
1011	wstat.muid = v9ses->uname;
1012	wstat.name = (char *) new_dentry->d_name.name;
1013	retval = p9_client_wstat(oldfid, &wstat);
1014
1015clunk_newdir:
1016	if (!retval) {
1017		if (new_inode) {
1018			if (S_ISDIR(new_inode->i_mode))
1019				clear_nlink(new_inode);
1020			else
1021				drop_nlink(new_inode);
1022		}
1023		if (S_ISDIR(old_inode->i_mode)) {
1024			if (!new_inode)
1025				inc_nlink(new_dir);
1026			drop_nlink(old_dir);
1027		}
1028		v9fs_invalidate_inode_attr(old_inode);
1029		v9fs_invalidate_inode_attr(old_dir);
1030		v9fs_invalidate_inode_attr(new_dir);
1031
1032		/* successful rename */
1033		d_move(old_dentry, new_dentry);
1034	}
1035	up_write(&v9ses->rename_sem);
1036	p9_client_clunk(newdirfid);
1037
1038clunk_olddir:
1039	p9_client_clunk(olddirfid);
1040
1041done:
1042	return retval;
1043}
1044
1045/**
1046 * v9fs_vfs_getattr - retrieve file metadata
1047 * @mnt: mount information
1048 * @dentry: file to get attributes on
1049 * @stat: metadata structure to populate
1050 *
1051 */
1052
1053static int
1054v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1055		 struct kstat *stat)
1056{
 
1057	struct v9fs_session_info *v9ses;
1058	struct p9_fid *fid;
1059	struct p9_wstat *st;
1060
1061	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 
1062	v9ses = v9fs_dentry2v9ses(dentry);
1063	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1064		generic_fillattr(dentry->d_inode, stat);
1065		return 0;
1066	}
1067	fid = v9fs_fid_lookup(dentry);
1068	if (IS_ERR(fid))
1069		return PTR_ERR(fid);
1070
1071	st = p9_client_stat(fid);
1072	if (IS_ERR(st))
1073		return PTR_ERR(st);
1074
1075	v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1076	generic_fillattr(dentry->d_inode, stat);
1077
1078	p9stat_free(st);
1079	kfree(st);
1080	return 0;
1081}
1082
1083/**
1084 * v9fs_vfs_setattr - set file metadata
1085 * @dentry: file whose metadata to set
1086 * @iattr: metadata assignment structure
1087 *
1088 */
1089
1090static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1091{
1092	int retval;
1093	struct v9fs_session_info *v9ses;
1094	struct p9_fid *fid;
1095	struct p9_wstat wstat;
1096
1097	p9_debug(P9_DEBUG_VFS, "\n");
1098	retval = inode_change_ok(dentry->d_inode, iattr);
1099	if (retval)
1100		return retval;
1101
1102	retval = -EPERM;
1103	v9ses = v9fs_dentry2v9ses(dentry);
1104	fid = v9fs_fid_lookup(dentry);
1105	if(IS_ERR(fid))
1106		return PTR_ERR(fid);
1107
1108	v9fs_blank_wstat(&wstat);
1109	if (iattr->ia_valid & ATTR_MODE)
1110		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1111
1112	if (iattr->ia_valid & ATTR_MTIME)
1113		wstat.mtime = iattr->ia_mtime.tv_sec;
1114
1115	if (iattr->ia_valid & ATTR_ATIME)
1116		wstat.atime = iattr->ia_atime.tv_sec;
1117
1118	if (iattr->ia_valid & ATTR_SIZE)
1119		wstat.length = iattr->ia_size;
1120
1121	if (v9fs_proto_dotu(v9ses)) {
1122		if (iattr->ia_valid & ATTR_UID)
1123			wstat.n_uid = iattr->ia_uid;
1124
1125		if (iattr->ia_valid & ATTR_GID)
1126			wstat.n_gid = iattr->ia_gid;
1127	}
1128
1129	/* Write all dirty data */
1130	if (S_ISREG(dentry->d_inode->i_mode))
1131		filemap_write_and_wait(dentry->d_inode->i_mapping);
1132
1133	retval = p9_client_wstat(fid, &wstat);
1134	if (retval < 0)
1135		return retval;
1136
1137	if ((iattr->ia_valid & ATTR_SIZE) &&
1138	    iattr->ia_size != i_size_read(dentry->d_inode))
1139		truncate_setsize(dentry->d_inode, iattr->ia_size);
1140
1141	v9fs_invalidate_inode_attr(dentry->d_inode);
1142
1143	setattr_copy(dentry->d_inode, iattr);
1144	mark_inode_dirty(dentry->d_inode);
1145	return 0;
1146}
1147
1148/**
1149 * v9fs_stat2inode - populate an inode structure with mistat info
1150 * @stat: Plan 9 metadata (mistat) structure
1151 * @inode: inode to populate
1152 * @sb: superblock of filesystem
1153 *
1154 */
1155
1156void
1157v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1158	struct super_block *sb)
1159{
1160	umode_t mode;
1161	char ext[32];
1162	char tag_name[14];
1163	unsigned int i_nlink;
1164	struct v9fs_session_info *v9ses = sb->s_fs_info;
1165	struct v9fs_inode *v9inode = V9FS_I(inode);
1166
1167	set_nlink(inode, 1);
1168
1169	inode->i_atime.tv_sec = stat->atime;
1170	inode->i_mtime.tv_sec = stat->mtime;
1171	inode->i_ctime.tv_sec = stat->mtime;
1172
1173	inode->i_uid = v9ses->dfltuid;
1174	inode->i_gid = v9ses->dfltgid;
1175
1176	if (v9fs_proto_dotu(v9ses)) {
1177		inode->i_uid = stat->n_uid;
1178		inode->i_gid = stat->n_gid;
1179	}
1180	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1181		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1182			/*
1183			 * Hadlink support got added later to
1184			 * to the .u extension. So there can be
1185			 * server out there that doesn't support
1186			 * this even with .u extension. So check
1187			 * for non NULL stat->extension
1188			 */
1189			strlcpy(ext, stat->extension, sizeof(ext));
1190			/* HARDLINKCOUNT %u */
1191			sscanf(ext, "%13s %u", tag_name, &i_nlink);
1192			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1193				set_nlink(inode, i_nlink);
1194		}
1195	}
1196	mode = p9mode2perm(v9ses, stat);
1197	mode |= inode->i_mode & ~S_IALLUGO;
1198	inode->i_mode = mode;
1199	i_size_write(inode, stat->length);
1200
1201	/* not real number of blocks, but 512 byte ones ... */
1202	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1203	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1204}
1205
1206/**
1207 * v9fs_qid2ino - convert qid into inode number
1208 * @qid: qid to hash
1209 *
1210 * BUG: potential for inode number collisions?
1211 */
1212
1213ino_t v9fs_qid2ino(struct p9_qid *qid)
1214{
1215	u64 path = qid->path + 2;
1216	ino_t i = 0;
1217
1218	if (sizeof(ino_t) == sizeof(path))
1219		memcpy(&i, &path, sizeof(ino_t));
1220	else
1221		i = (ino_t) (path ^ (path >> 32));
1222
1223	return i;
1224}
1225
1226/**
1227 * v9fs_readlink - read a symlink's location (internal version)
1228 * @dentry: dentry for symlink
1229 * @buffer: buffer to load symlink location into
1230 * @buflen: length of buffer
1231 *
1232 */
1233
1234static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1235{
1236	int retval;
1237
1238	struct v9fs_session_info *v9ses;
1239	struct p9_fid *fid;
1240	struct p9_wstat *st;
1241
1242	p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1243	retval = -EPERM;
1244	v9ses = v9fs_dentry2v9ses(dentry);
1245	fid = v9fs_fid_lookup(dentry);
1246	if (IS_ERR(fid))
1247		return PTR_ERR(fid);
1248
1249	if (!v9fs_proto_dotu(v9ses))
1250		return -EBADF;
1251
1252	st = p9_client_stat(fid);
1253	if (IS_ERR(st))
1254		return PTR_ERR(st);
1255
1256	if (!(st->mode & P9_DMSYMLINK)) {
1257		retval = -EINVAL;
1258		goto done;
1259	}
1260
1261	/* copy extension buffer into buffer */
1262	retval = min(strlen(st->extension)+1, (size_t)buflen);
1263	memcpy(buffer, st->extension, retval);
1264
1265	p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n",
1266		 dentry->d_name.name, st->extension, buflen, buffer);
1267
 
1268done:
1269	p9stat_free(st);
1270	kfree(st);
1271	return retval;
1272}
1273
1274/**
1275 * v9fs_vfs_follow_link - follow a symlink path
1276 * @dentry: dentry for symlink
1277 * @nd: nameidata
1278 *
1279 */
1280
1281static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1282{
1283	int len = 0;
1284	char *link = __getname();
1285
1286	p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
1287
1288	if (!link)
1289		link = ERR_PTR(-ENOMEM);
1290	else {
1291		len = v9fs_readlink(dentry, link, PATH_MAX);
1292
1293		if (len < 0) {
1294			__putname(link);
1295			link = ERR_PTR(len);
1296		} else
1297			link[min(len, PATH_MAX-1)] = 0;
1298	}
1299	nd_set_link(nd, link);
1300
1301	return NULL;
1302}
1303
1304/**
1305 * v9fs_vfs_put_link - release a symlink path
1306 * @dentry: dentry for symlink
1307 * @nd: nameidata
1308 * @p: unused
1309 *
1310 */
1311
1312void
1313v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1314{
1315	char *s = nd_get_link(nd);
1316
1317	p9_debug(P9_DEBUG_VFS, " %s %s\n",
1318		 dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
1319	if (!IS_ERR(s))
1320		__putname(s);
1321}
1322
1323/**
1324 * v9fs_vfs_mkspecial - create a special file
1325 * @dir: inode to create special file in
1326 * @dentry: dentry to create
1327 * @mode: mode to create special file
1328 * @extension: 9p2000.u format extension string representing special file
1329 *
1330 */
1331
1332static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1333	u32 perm, const char *extension)
1334{
 
1335	struct p9_fid *fid;
1336	struct v9fs_session_info *v9ses;
1337
1338	v9ses = v9fs_inode2v9ses(dir);
1339	if (!v9fs_proto_dotu(v9ses)) {
1340		p9_debug(P9_DEBUG_ERROR, "not extended\n");
1341		return -EPERM;
1342	}
1343
 
1344	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1345								P9_OREAD);
1346	if (IS_ERR(fid))
1347		return PTR_ERR(fid);
1348
1349	v9fs_invalidate_inode_attr(dir);
1350	p9_client_clunk(fid);
1351	return 0;
1352}
1353
1354/**
1355 * v9fs_vfs_symlink - helper function to create symlinks
1356 * @dir: directory inode containing symlink
1357 * @dentry: dentry for symlink
1358 * @symname: symlink data
1359 *
1360 * See Also: 9P2000.u RFC for more information
1361 *
1362 */
1363
1364static int
1365v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1366{
1367	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1368		 dir->i_ino, dentry->d_name.name, symname);
1369
1370	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1371}
1372
1373/**
1374 * v9fs_vfs_link - create a hardlink
1375 * @old_dentry: dentry for file to link to
1376 * @dir: inode destination for new link
1377 * @dentry: dentry for link
1378 *
1379 */
1380
1381static int
1382v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1383	      struct dentry *dentry)
1384{
1385	int retval;
1386	char *name;
1387	struct p9_fid *oldfid;
1388
1389	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1390		 dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
 
1391
1392	oldfid = v9fs_fid_clone(old_dentry);
1393	if (IS_ERR(oldfid))
1394		return PTR_ERR(oldfid);
1395
1396	name = __getname();
1397	if (unlikely(!name)) {
1398		retval = -ENOMEM;
1399		goto clunk_fid;
1400	}
1401
1402	sprintf(name, "%d\n", oldfid->fid);
1403	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1404	__putname(name);
1405	if (!retval) {
1406		v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1407		v9fs_invalidate_inode_attr(dir);
1408	}
1409clunk_fid:
1410	p9_client_clunk(oldfid);
1411	return retval;
1412}
1413
1414/**
1415 * v9fs_vfs_mknod - create a special file
1416 * @dir: inode destination for new link
1417 * @dentry: dentry for file
1418 * @mode: mode for creation
1419 * @rdev: device associated with special file
1420 *
1421 */
1422
1423static int
1424v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1425{
1426	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1427	int retval;
1428	char *name;
1429	u32 perm;
1430
1431	p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
1432		 dir->i_ino, dentry->d_name.name, mode,
1433		 MAJOR(rdev), MINOR(rdev));
1434
1435	if (!new_valid_dev(rdev))
1436		return -EINVAL;
1437
1438	name = __getname();
1439	if (!name)
1440		return -ENOMEM;
1441	/* build extension */
1442	if (S_ISBLK(mode))
1443		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1444	else if (S_ISCHR(mode))
1445		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1446	else if (S_ISFIFO(mode))
1447		*name = 0;
1448	else if (S_ISSOCK(mode))
1449		*name = 0;
1450	else {
1451		__putname(name);
1452		return -EINVAL;
1453	}
1454
1455	perm = unixmode2p9mode(v9ses, mode);
1456	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1457	__putname(name);
1458
1459	return retval;
1460}
1461
1462int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1463{
1464	int umode;
1465	dev_t rdev;
1466	loff_t i_size;
1467	struct p9_wstat *st;
1468	struct v9fs_session_info *v9ses;
1469
1470	v9ses = v9fs_inode2v9ses(inode);
1471	st = p9_client_stat(fid);
1472	if (IS_ERR(st))
1473		return PTR_ERR(st);
1474	/*
1475	 * Don't update inode if the file type is different
1476	 */
1477	umode = p9mode2unixmode(v9ses, st, &rdev);
1478	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1479		goto out;
1480
1481	spin_lock(&inode->i_lock);
1482	/*
1483	 * We don't want to refresh inode->i_size,
1484	 * because we may have cached data
1485	 */
1486	i_size = inode->i_size;
1487	v9fs_stat2inode(st, inode, inode->i_sb);
1488	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1489		inode->i_size = i_size;
1490	spin_unlock(&inode->i_lock);
1491out:
1492	p9stat_free(st);
1493	kfree(st);
1494	return 0;
1495}
1496
1497static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1498	.create = v9fs_vfs_create,
1499	.lookup = v9fs_vfs_lookup,
1500	.atomic_open = v9fs_vfs_atomic_open,
1501	.symlink = v9fs_vfs_symlink,
1502	.link = v9fs_vfs_link,
1503	.unlink = v9fs_vfs_unlink,
1504	.mkdir = v9fs_vfs_mkdir,
1505	.rmdir = v9fs_vfs_rmdir,
1506	.mknod = v9fs_vfs_mknod,
1507	.rename = v9fs_vfs_rename,
1508	.getattr = v9fs_vfs_getattr,
1509	.setattr = v9fs_vfs_setattr,
1510};
1511
1512static const struct inode_operations v9fs_dir_inode_operations = {
1513	.create = v9fs_vfs_create,
1514	.lookup = v9fs_vfs_lookup,
1515	.atomic_open = v9fs_vfs_atomic_open,
1516	.unlink = v9fs_vfs_unlink,
1517	.mkdir = v9fs_vfs_mkdir,
1518	.rmdir = v9fs_vfs_rmdir,
1519	.mknod = v9fs_vfs_mknod,
1520	.rename = v9fs_vfs_rename,
1521	.getattr = v9fs_vfs_getattr,
1522	.setattr = v9fs_vfs_setattr,
1523};
1524
1525static const struct inode_operations v9fs_file_inode_operations = {
1526	.getattr = v9fs_vfs_getattr,
1527	.setattr = v9fs_vfs_setattr,
1528};
1529
1530static const struct inode_operations v9fs_symlink_inode_operations = {
1531	.readlink = generic_readlink,
1532	.follow_link = v9fs_vfs_follow_link,
1533	.put_link = v9fs_vfs_put_link,
1534	.getattr = v9fs_vfs_getattr,
1535	.setattr = v9fs_vfs_setattr,
1536};
1537