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v4.6
 
   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
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/fs/9p/vfs_inode.c
   4 *
   5 * This file contains vfs inode ops for the 9P2000 protocol.
   6 *
   7 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   8 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   9 */
  10
  11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13#include <linux/module.h>
  14#include <linux/errno.h>
  15#include <linux/fs.h>
  16#include <linux/file.h>
  17#include <linux/pagemap.h>
  18#include <linux/stat.h>
  19#include <linux/string.h>
  20#include <linux/inet.h>
  21#include <linux/namei.h>
  22#include <linux/idr.h>
  23#include <linux/sched.h>
  24#include <linux/slab.h>
  25#include <linux/xattr.h>
  26#include <linux/posix_acl.h>
  27#include <net/9p/9p.h>
  28#include <net/9p/client.h>
  29
  30#include "v9fs.h"
  31#include "v9fs_vfs.h"
  32#include "fid.h"
  33#include "cache.h"
  34#include "xattr.h"
  35#include "acl.h"
  36
  37static const struct inode_operations v9fs_dir_inode_operations;
  38static const struct inode_operations v9fs_dir_inode_operations_dotu;
  39static const struct inode_operations v9fs_file_inode_operations;
  40static const struct inode_operations v9fs_symlink_inode_operations;
  41
  42/**
  43 * unixmode2p9mode - convert unix mode bits to plan 9
  44 * @v9ses: v9fs session information
  45 * @mode: mode to convert
  46 *
  47 */
  48
  49static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
  50{
  51	int res;
  52	res = mode & 0777;
  53	if (S_ISDIR(mode))
  54		res |= P9_DMDIR;
  55	if (v9fs_proto_dotu(v9ses)) {
  56		if (v9ses->nodev == 0) {
  57			if (S_ISSOCK(mode))
  58				res |= P9_DMSOCKET;
  59			if (S_ISFIFO(mode))
  60				res |= P9_DMNAMEDPIPE;
  61			if (S_ISBLK(mode))
  62				res |= P9_DMDEVICE;
  63			if (S_ISCHR(mode))
  64				res |= P9_DMDEVICE;
  65		}
  66
  67		if ((mode & S_ISUID) == S_ISUID)
  68			res |= P9_DMSETUID;
  69		if ((mode & S_ISGID) == S_ISGID)
  70			res |= P9_DMSETGID;
  71		if ((mode & S_ISVTX) == S_ISVTX)
  72			res |= P9_DMSETVTX;
  73	}
  74	return res;
  75}
  76
  77/**
  78 * p9mode2perm- convert plan9 mode bits to unix permission bits
  79 * @v9ses: v9fs session information
  80 * @stat: p9_wstat from which mode need to be derived
  81 *
  82 */
  83static int p9mode2perm(struct v9fs_session_info *v9ses,
  84		       struct p9_wstat *stat)
  85{
  86	int res;
  87	int mode = stat->mode;
  88
  89	res = mode & S_IALLUGO;
  90	if (v9fs_proto_dotu(v9ses)) {
  91		if ((mode & P9_DMSETUID) == P9_DMSETUID)
  92			res |= S_ISUID;
  93
  94		if ((mode & P9_DMSETGID) == P9_DMSETGID)
  95			res |= S_ISGID;
  96
  97		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
  98			res |= S_ISVTX;
  99	}
 100	return res;
 101}
 102
 103/**
 104 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 105 * @v9ses: v9fs session information
 106 * @stat: p9_wstat from which mode need to be derived
 107 * @rdev: major number, minor number in case of device files.
 108 *
 109 */
 110static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 111			       struct p9_wstat *stat, dev_t *rdev)
 112{
 113	int res;
 114	u32 mode = stat->mode;
 115
 116	*rdev = 0;
 117	res = p9mode2perm(v9ses, stat);
 118
 119	if ((mode & P9_DMDIR) == P9_DMDIR)
 120		res |= S_IFDIR;
 121	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 122		res |= S_IFLNK;
 123	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 124		 && (v9ses->nodev == 0))
 125		res |= S_IFSOCK;
 126	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 127		 && (v9ses->nodev == 0))
 128		res |= S_IFIFO;
 129	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 130		 && (v9ses->nodev == 0)) {
 131		char type = 0, ext[32];
 132		int major = -1, minor = -1;
 133
 134		strlcpy(ext, stat->extension, sizeof(ext));
 135		sscanf(ext, "%c %i %i", &type, &major, &minor);
 136		switch (type) {
 137		case 'c':
 138			res |= S_IFCHR;
 139			break;
 140		case 'b':
 141			res |= S_IFBLK;
 142			break;
 143		default:
 144			p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 145				 type, stat->extension);
 146		}
 147		*rdev = MKDEV(major, minor);
 148	} else
 149		res |= S_IFREG;
 150
 151	return res;
 152}
 153
 154/**
 155 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 156 * @uflags: flags to convert
 157 * @extended: if .u extensions are active
 158 */
 159
 160int v9fs_uflags2omode(int uflags, int extended)
 161{
 162	int ret;
 163
 164	ret = 0;
 165	switch (uflags&3) {
 166	default:
 167	case O_RDONLY:
 168		ret = P9_OREAD;
 169		break;
 170
 171	case O_WRONLY:
 172		ret = P9_OWRITE;
 173		break;
 174
 175	case O_RDWR:
 176		ret = P9_ORDWR;
 177		break;
 178	}
 179
 180	if (extended) {
 181		if (uflags & O_EXCL)
 182			ret |= P9_OEXCL;
 183
 184		if (uflags & O_APPEND)
 185			ret |= P9_OAPPEND;
 186	}
 187
 188	return ret;
 189}
 190
 191/**
 192 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 193 * @wstat: structure to initialize
 194 *
 195 */
 196
 197void
 198v9fs_blank_wstat(struct p9_wstat *wstat)
 199{
 200	wstat->type = ~0;
 201	wstat->dev = ~0;
 202	wstat->qid.type = ~0;
 203	wstat->qid.version = ~0;
 204	*((long long *)&wstat->qid.path) = ~0;
 205	wstat->mode = ~0;
 206	wstat->atime = ~0;
 207	wstat->mtime = ~0;
 208	wstat->length = ~0;
 209	wstat->name = NULL;
 210	wstat->uid = NULL;
 211	wstat->gid = NULL;
 212	wstat->muid = NULL;
 213	wstat->n_uid = INVALID_UID;
 214	wstat->n_gid = INVALID_GID;
 215	wstat->n_muid = INVALID_UID;
 216	wstat->extension = NULL;
 217}
 218
 219/**
 220 * v9fs_alloc_inode - helper function to allocate an inode
 221 *
 222 */
 223struct inode *v9fs_alloc_inode(struct super_block *sb)
 224{
 225	struct v9fs_inode *v9inode;
 226	v9inode = kmem_cache_alloc(v9fs_inode_cache, GFP_KERNEL);
 
 227	if (!v9inode)
 228		return NULL;
 229#ifdef CONFIG_9P_FSCACHE
 230	v9inode->fscache = NULL;
 231	mutex_init(&v9inode->fscache_lock);
 232#endif
 233	v9inode->writeback_fid = NULL;
 234	v9inode->cache_validity = 0;
 235	mutex_init(&v9inode->v_mutex);
 236	return &v9inode->vfs_inode;
 237}
 238
 239/**
 240 * v9fs_free_inode - destroy an inode
 241 *
 242 */
 243
 244void v9fs_free_inode(struct inode *inode)
 245{
 
 246	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 247}
 248
 
 
 
 
 
 249int v9fs_init_inode(struct v9fs_session_info *v9ses,
 250		    struct inode *inode, umode_t mode, dev_t rdev)
 251{
 252	int err = 0;
 253
 254	inode_init_owner(&init_user_ns,inode,  NULL, mode);
 255	inode->i_blocks = 0;
 256	inode->i_rdev = rdev;
 257	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 258	inode->i_mapping->a_ops = &v9fs_addr_operations;
 259	inode->i_private = NULL;
 260
 261	switch (mode & S_IFMT) {
 262	case S_IFIFO:
 263	case S_IFBLK:
 264	case S_IFCHR:
 265	case S_IFSOCK:
 266		if (v9fs_proto_dotl(v9ses)) {
 267			inode->i_op = &v9fs_file_inode_operations_dotl;
 268		} else if (v9fs_proto_dotu(v9ses)) {
 269			inode->i_op = &v9fs_file_inode_operations;
 270		} else {
 271			p9_debug(P9_DEBUG_ERROR,
 272				 "special files without extended mode\n");
 273			err = -EINVAL;
 274			goto error;
 275		}
 276		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 277		break;
 278	case S_IFREG:
 279		if (v9fs_proto_dotl(v9ses)) {
 280			inode->i_op = &v9fs_file_inode_operations_dotl;
 281			if (v9ses->cache == CACHE_LOOSE ||
 282			    v9ses->cache == CACHE_FSCACHE)
 283				inode->i_fop =
 284					&v9fs_cached_file_operations_dotl;
 285			else if (v9ses->cache == CACHE_MMAP)
 286				inode->i_fop = &v9fs_mmap_file_operations_dotl;
 287			else
 288				inode->i_fop = &v9fs_file_operations_dotl;
 289		} else {
 290			inode->i_op = &v9fs_file_inode_operations;
 291			if (v9ses->cache == CACHE_LOOSE ||
 292			    v9ses->cache == CACHE_FSCACHE)
 293				inode->i_fop =
 294					&v9fs_cached_file_operations;
 295			else if (v9ses->cache == CACHE_MMAP)
 296				inode->i_fop = &v9fs_mmap_file_operations;
 297			else
 298				inode->i_fop = &v9fs_file_operations;
 299		}
 300
 301		break;
 302	case S_IFLNK:
 303		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 304			p9_debug(P9_DEBUG_ERROR,
 305				 "extended modes used with legacy protocol\n");
 306			err = -EINVAL;
 307			goto error;
 308		}
 309
 310		if (v9fs_proto_dotl(v9ses))
 311			inode->i_op = &v9fs_symlink_inode_operations_dotl;
 312		else
 313			inode->i_op = &v9fs_symlink_inode_operations;
 314
 315		break;
 316	case S_IFDIR:
 317		inc_nlink(inode);
 318		if (v9fs_proto_dotl(v9ses))
 319			inode->i_op = &v9fs_dir_inode_operations_dotl;
 320		else if (v9fs_proto_dotu(v9ses))
 321			inode->i_op = &v9fs_dir_inode_operations_dotu;
 322		else
 323			inode->i_op = &v9fs_dir_inode_operations;
 324
 325		if (v9fs_proto_dotl(v9ses))
 326			inode->i_fop = &v9fs_dir_operations_dotl;
 327		else
 328			inode->i_fop = &v9fs_dir_operations;
 329
 330		break;
 331	default:
 332		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 333			 mode, mode & S_IFMT);
 334		err = -EINVAL;
 335		goto error;
 336	}
 337error:
 338	return err;
 339
 340}
 341
 342/**
 343 * v9fs_get_inode - helper function to setup an inode
 344 * @sb: superblock
 345 * @mode: mode to setup inode with
 346 *
 347 */
 348
 349struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 350{
 351	int err;
 352	struct inode *inode;
 353	struct v9fs_session_info *v9ses = sb->s_fs_info;
 354
 355	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 356
 357	inode = new_inode(sb);
 358	if (!inode) {
 359		pr_warn("%s (%d): Problem allocating inode\n",
 360			__func__, task_pid_nr(current));
 361		return ERR_PTR(-ENOMEM);
 362	}
 363	err = v9fs_init_inode(v9ses, inode, mode, rdev);
 364	if (err) {
 365		iput(inode);
 366		return ERR_PTR(err);
 367	}
 368	return inode;
 369}
 370
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 371/**
 372 * v9fs_clear_inode - release an inode
 373 * @inode: inode to release
 374 *
 375 */
 376void v9fs_evict_inode(struct inode *inode)
 377{
 378	struct v9fs_inode *v9inode = V9FS_I(inode);
 379
 380	truncate_inode_pages_final(&inode->i_data);
 381	clear_inode(inode);
 382	filemap_fdatawrite(&inode->i_data);
 383
 384	v9fs_cache_inode_put_cookie(inode);
 385	/* clunk the fid stashed in writeback_fid */
 386	if (v9inode->writeback_fid) {
 387		p9_client_clunk(v9inode->writeback_fid);
 388		v9inode->writeback_fid = NULL;
 389	}
 390}
 391
 392static int v9fs_test_inode(struct inode *inode, void *data)
 393{
 394	int umode;
 395	dev_t rdev;
 396	struct v9fs_inode *v9inode = V9FS_I(inode);
 397	struct p9_wstat *st = (struct p9_wstat *)data;
 398	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 399
 400	umode = p9mode2unixmode(v9ses, st, &rdev);
 401	/* don't match inode of different type */
 402	if (inode_wrong_type(inode, umode))
 403		return 0;
 404
 405	/* compare qid details */
 406	if (memcmp(&v9inode->qid.version,
 407		   &st->qid.version, sizeof(v9inode->qid.version)))
 408		return 0;
 409
 410	if (v9inode->qid.type != st->qid.type)
 411		return 0;
 412
 413	if (v9inode->qid.path != st->qid.path)
 414		return 0;
 415	return 1;
 416}
 417
 418static int v9fs_test_new_inode(struct inode *inode, void *data)
 419{
 420	return 0;
 421}
 422
 423static int v9fs_set_inode(struct inode *inode,  void *data)
 424{
 425	struct v9fs_inode *v9inode = V9FS_I(inode);
 426	struct p9_wstat *st = (struct p9_wstat *)data;
 427
 428	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 429	return 0;
 430}
 431
 432static struct inode *v9fs_qid_iget(struct super_block *sb,
 433				   struct p9_qid *qid,
 434				   struct p9_wstat *st,
 435				   int new)
 436{
 437	dev_t rdev;
 438	int retval;
 439	umode_t umode;
 440	unsigned long i_ino;
 441	struct inode *inode;
 442	struct v9fs_session_info *v9ses = sb->s_fs_info;
 443	int (*test)(struct inode *, void *);
 444
 445	if (new)
 446		test = v9fs_test_new_inode;
 447	else
 448		test = v9fs_test_inode;
 449
 450	i_ino = v9fs_qid2ino(qid);
 451	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 452	if (!inode)
 453		return ERR_PTR(-ENOMEM);
 454	if (!(inode->i_state & I_NEW))
 455		return inode;
 456	/*
 457	 * initialize the inode with the stat info
 458	 * FIXME!! we may need support for stale inodes
 459	 * later.
 460	 */
 461	inode->i_ino = i_ino;
 462	umode = p9mode2unixmode(v9ses, st, &rdev);
 463	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 464	if (retval)
 465		goto error;
 466
 467	v9fs_stat2inode(st, inode, sb, 0);
 468	v9fs_cache_inode_get_cookie(inode);
 469	unlock_new_inode(inode);
 470	return inode;
 471error:
 472	iget_failed(inode);
 473	return ERR_PTR(retval);
 474
 475}
 476
 477struct inode *
 478v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 479		    struct super_block *sb, int new)
 480{
 481	struct p9_wstat *st;
 482	struct inode *inode = NULL;
 483
 484	st = p9_client_stat(fid);
 485	if (IS_ERR(st))
 486		return ERR_CAST(st);
 487
 488	inode = v9fs_qid_iget(sb, &st->qid, st, new);
 489	p9stat_free(st);
 490	kfree(st);
 491	return inode;
 492}
 493
 494/**
 495 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 496 * plan 9 AT flag.
 497 * @flags: flags to convert
 498 */
 499static int v9fs_at_to_dotl_flags(int flags)
 500{
 501	int rflags = 0;
 502	if (flags & AT_REMOVEDIR)
 503		rflags |= P9_DOTL_AT_REMOVEDIR;
 504	return rflags;
 505}
 506
 507/**
 508 * v9fs_dec_count - helper functon to drop i_nlink.
 509 *
 510 * If a directory had nlink <= 2 (including . and ..), then we should not drop
 511 * the link count, which indicates the underlying exported fs doesn't maintain
 512 * nlink accurately. e.g.
 513 * - overlayfs sets nlink to 1 for merged dir
 514 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
 515 *   than EXT4_LINK_MAX (65000) links.
 516 *
 517 * @inode: inode whose nlink is being dropped
 518 */
 519static void v9fs_dec_count(struct inode *inode)
 520{
 521	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
 522		drop_nlink(inode);
 523}
 524
 525/**
 526 * v9fs_remove - helper function to remove files and directories
 527 * @dir: directory inode that is being deleted
 528 * @dentry:  dentry that is being deleted
 529 * @flags: removing a directory
 530 *
 531 */
 532
 533static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 534{
 535	struct inode *inode;
 536	int retval = -EOPNOTSUPP;
 537	struct p9_fid *v9fid, *dfid;
 538	struct v9fs_session_info *v9ses;
 539
 540	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 541		 dir, dentry, flags);
 542
 543	v9ses = v9fs_inode2v9ses(dir);
 544	inode = d_inode(dentry);
 545	dfid = v9fs_parent_fid(dentry);
 546	if (IS_ERR(dfid)) {
 547		retval = PTR_ERR(dfid);
 548		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 549		return retval;
 550	}
 551	if (v9fs_proto_dotl(v9ses))
 552		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 553					    v9fs_at_to_dotl_flags(flags));
 554	p9_client_clunk(dfid);
 555	if (retval == -EOPNOTSUPP) {
 556		/* Try the one based on path */
 557		v9fid = v9fs_fid_clone(dentry);
 558		if (IS_ERR(v9fid))
 559			return PTR_ERR(v9fid);
 560		retval = p9_client_remove(v9fid);
 561	}
 562	if (!retval) {
 563		/*
 564		 * directories on unlink should have zero
 565		 * link count
 566		 */
 567		if (flags & AT_REMOVEDIR) {
 568			clear_nlink(inode);
 569			v9fs_dec_count(dir);
 570		} else
 571			v9fs_dec_count(inode);
 572
 573		v9fs_invalidate_inode_attr(inode);
 574		v9fs_invalidate_inode_attr(dir);
 575
 576		/* invalidate all fids associated with dentry */
 577		/* NOTE: This will not include open fids */
 578		dentry->d_op->d_release(dentry);
 579	}
 580	return retval;
 581}
 582
 583/**
 584 * v9fs_create - Create a file
 585 * @v9ses: session information
 586 * @dir: directory that dentry is being created in
 587 * @dentry:  dentry that is being created
 588 * @extension: 9p2000.u extension string to support devices, etc.
 589 * @perm: create permissions
 590 * @mode: open mode
 591 *
 592 */
 593static struct p9_fid *
 594v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 595		struct dentry *dentry, char *extension, u32 perm, u8 mode)
 596{
 597	int err;
 598	const unsigned char *name;
 599	struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
 600	struct inode *inode;
 601
 602	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 603
 604	err = 0;
 605	name = dentry->d_name.name;
 606	dfid = v9fs_parent_fid(dentry);
 
 
 607	if (IS_ERR(dfid)) {
 608		err = PTR_ERR(dfid);
 609		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 610		return ERR_PTR(err);
 611	}
 612
 613	/* clone a fid to use for creation */
 614	ofid = clone_fid(dfid);
 615	if (IS_ERR(ofid)) {
 616		err = PTR_ERR(ofid);
 617		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 618		p9_client_clunk(dfid);
 619		return ERR_PTR(err);
 620	}
 621
 622	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 623	if (err < 0) {
 624		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 625		p9_client_clunk(dfid);
 626		goto error;
 627	}
 628
 629	if (!(perm & P9_DMLINK)) {
 630		/* now walk from the parent so we can get unopened fid */
 631		fid = p9_client_walk(dfid, 1, &name, 1);
 632		if (IS_ERR(fid)) {
 633			err = PTR_ERR(fid);
 634			p9_debug(P9_DEBUG_VFS,
 635				   "p9_client_walk failed %d\n", err);
 636			fid = NULL;
 637			p9_client_clunk(dfid);
 638			goto error;
 639		}
 640		/*
 641		 * instantiate inode and assign the unopened fid to the dentry
 642		 */
 643		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 644		if (IS_ERR(inode)) {
 645			err = PTR_ERR(inode);
 646			p9_debug(P9_DEBUG_VFS,
 647				   "inode creation failed %d\n", err);
 648			p9_client_clunk(dfid);
 649			goto error;
 650		}
 651		v9fs_fid_add(dentry, fid);
 652		d_instantiate(dentry, inode);
 653	}
 654	p9_client_clunk(dfid);
 655	return ofid;
 656error:
 657	if (ofid)
 658		p9_client_clunk(ofid);
 659
 660	if (fid)
 661		p9_client_clunk(fid);
 662
 663	return ERR_PTR(err);
 664}
 665
 666/**
 667 * v9fs_vfs_create - VFS hook to create a regular file
 668 *
 669 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 670 * for mknod(2).
 671 *
 672 * @dir: directory inode that is being created
 673 * @dentry:  dentry that is being deleted
 674 * @mode: create permissions
 675 *
 676 */
 677
 678static int
 679v9fs_vfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 680		struct dentry *dentry, umode_t mode, bool excl)
 681{
 682	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 683	u32 perm = unixmode2p9mode(v9ses, mode);
 684	struct p9_fid *fid;
 685
 686	/* P9_OEXCL? */
 687	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 688	if (IS_ERR(fid))
 689		return PTR_ERR(fid);
 690
 691	v9fs_invalidate_inode_attr(dir);
 692	p9_client_clunk(fid);
 693
 694	return 0;
 695}
 696
 697/**
 698 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 699 * @dir:  inode that is being unlinked
 700 * @dentry: dentry that is being unlinked
 701 * @mode: mode for new directory
 702 *
 703 */
 704
 705static int v9fs_vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 706			  struct dentry *dentry, umode_t mode)
 707{
 708	int err;
 709	u32 perm;
 710	struct p9_fid *fid;
 711	struct v9fs_session_info *v9ses;
 712
 713	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 714	err = 0;
 715	v9ses = v9fs_inode2v9ses(dir);
 716	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 717	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 718	if (IS_ERR(fid)) {
 719		err = PTR_ERR(fid);
 720		fid = NULL;
 721	} else {
 722		inc_nlink(dir);
 723		v9fs_invalidate_inode_attr(dir);
 724	}
 725
 726	if (fid)
 727		p9_client_clunk(fid);
 728
 729	return err;
 730}
 731
 732/**
 733 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 734 * @dir:  inode that is being walked from
 735 * @dentry: dentry that is being walked to?
 736 * @flags: lookup flags (unused)
 737 *
 738 */
 739
 740struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 741				      unsigned int flags)
 742{
 743	struct dentry *res;
 744	struct v9fs_session_info *v9ses;
 745	struct p9_fid *dfid, *fid;
 746	struct inode *inode;
 747	const unsigned char *name;
 748
 749	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
 750		 dir, dentry, dentry, flags);
 751
 752	if (dentry->d_name.len > NAME_MAX)
 753		return ERR_PTR(-ENAMETOOLONG);
 754
 755	v9ses = v9fs_inode2v9ses(dir);
 756	/* We can walk d_parent because we hold the dir->i_mutex */
 757	dfid = v9fs_parent_fid(dentry);
 758	if (IS_ERR(dfid))
 759		return ERR_CAST(dfid);
 760
 
 
 
 
 
 
 
 
 
 761	/*
 762	 * Make sure we don't use a wrong inode due to parallel
 763	 * unlink. For cached mode create calls request for new
 764	 * inode. But with cache disabled, lookup should do this.
 765	 */
 766	name = dentry->d_name.name;
 767	fid = p9_client_walk(dfid, 1, &name, 1);
 768	p9_client_clunk(dfid);
 769	if (fid == ERR_PTR(-ENOENT))
 770		inode = NULL;
 771	else if (IS_ERR(fid))
 772		inode = ERR_CAST(fid);
 773	else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 774		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 775	else
 776		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 
 
 
 
 777	/*
 778	 * If we had a rename on the server and a parallel lookup
 779	 * for the new name, then make sure we instantiate with
 780	 * the new name. ie look up for a/b, while on server somebody
 781	 * moved b under k and client parallely did a lookup for
 782	 * k/b.
 783	 */
 784	res = d_splice_alias(inode, dentry);
 785	if (!IS_ERR(fid)) {
 786		if (!res)
 787			v9fs_fid_add(dentry, fid);
 788		else if (!IS_ERR(res))
 789			v9fs_fid_add(res, fid);
 790		else
 791			p9_client_clunk(fid);
 792	}
 793	return res;
 794}
 795
 796static int
 797v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 798		     struct file *file, unsigned flags, umode_t mode)
 
 799{
 800	int err;
 801	u32 perm;
 802	struct v9fs_inode *v9inode;
 803	struct v9fs_session_info *v9ses;
 804	struct p9_fid *fid, *inode_fid;
 805	struct dentry *res = NULL;
 806	struct inode *inode;
 807
 808	if (d_in_lookup(dentry)) {
 809		res = v9fs_vfs_lookup(dir, dentry, 0);
 810		if (IS_ERR(res))
 811			return PTR_ERR(res);
 812
 813		if (res)
 814			dentry = res;
 815	}
 816
 817	/* Only creates */
 818	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
 819		return finish_no_open(file, res);
 820
 821	err = 0;
 822
 823	v9ses = v9fs_inode2v9ses(dir);
 824	perm = unixmode2p9mode(v9ses, mode);
 825	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 826				v9fs_uflags2omode(flags,
 827						v9fs_proto_dotu(v9ses)));
 828	if (IS_ERR(fid)) {
 829		err = PTR_ERR(fid);
 830		fid = NULL;
 831		goto error;
 832	}
 833
 834	v9fs_invalidate_inode_attr(dir);
 835	inode = d_inode(dentry);
 836	v9inode = V9FS_I(inode);
 837	mutex_lock(&v9inode->v_mutex);
 838	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
 839	    !v9inode->writeback_fid &&
 840	    ((flags & O_ACCMODE) != O_RDONLY)) {
 841		/*
 842		 * clone a fid and add it to writeback_fid
 843		 * we do it during open time instead of
 844		 * page dirty time via write_begin/page_mkwrite
 845		 * because we want write after unlink usecase
 846		 * to work.
 847		 */
 848		inode_fid = v9fs_writeback_fid(dentry);
 849		if (IS_ERR(inode_fid)) {
 850			err = PTR_ERR(inode_fid);
 851			mutex_unlock(&v9inode->v_mutex);
 852			goto error;
 853		}
 854		v9inode->writeback_fid = (void *) inode_fid;
 855	}
 856	mutex_unlock(&v9inode->v_mutex);
 857	err = finish_open(file, dentry, generic_file_open);
 858	if (err)
 859		goto error;
 860
 861	file->private_data = fid;
 862	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 863		v9fs_cache_inode_set_cookie(d_inode(dentry), file);
 864	v9fs_open_fid_add(inode, fid);
 865
 866	file->f_mode |= FMODE_CREATED;
 867out:
 868	dput(res);
 869	return err;
 870
 871error:
 872	if (fid)
 873		p9_client_clunk(fid);
 874	goto out;
 875}
 876
 877/**
 878 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 879 * @i:  inode that is being unlinked
 880 * @d: dentry that is being unlinked
 881 *
 882 */
 883
 884int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 885{
 886	return v9fs_remove(i, d, 0);
 887}
 888
 889/**
 890 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 891 * @i:  inode that is being unlinked
 892 * @d: dentry that is being unlinked
 893 *
 894 */
 895
 896int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 897{
 898	return v9fs_remove(i, d, AT_REMOVEDIR);
 899}
 900
 901/**
 902 * v9fs_vfs_rename - VFS hook to rename an inode
 903 * @old_dir:  old dir inode
 904 * @old_dentry: old dentry
 905 * @new_dir: new dir inode
 906 * @new_dentry: new dentry
 907 *
 908 */
 909
 910int
 911v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 912		struct dentry *old_dentry, struct inode *new_dir,
 913		struct dentry *new_dentry, unsigned int flags)
 914{
 915	int retval;
 916	struct inode *old_inode;
 917	struct inode *new_inode;
 918	struct v9fs_session_info *v9ses;
 919	struct p9_fid *oldfid, *dfid;
 920	struct p9_fid *olddirfid;
 921	struct p9_fid *newdirfid;
 922	struct p9_wstat wstat;
 923
 924	if (flags)
 925		return -EINVAL;
 926
 927	p9_debug(P9_DEBUG_VFS, "\n");
 928	retval = 0;
 929	old_inode = d_inode(old_dentry);
 930	new_inode = d_inode(new_dentry);
 931	v9ses = v9fs_inode2v9ses(old_inode);
 932	oldfid = v9fs_fid_lookup(old_dentry);
 933	if (IS_ERR(oldfid))
 934		return PTR_ERR(oldfid);
 935
 936	dfid = v9fs_parent_fid(old_dentry);
 937	olddirfid = clone_fid(dfid);
 938	if (dfid && !IS_ERR(dfid))
 939		p9_client_clunk(dfid);
 940
 941	if (IS_ERR(olddirfid)) {
 942		retval = PTR_ERR(olddirfid);
 943		goto done;
 944	}
 945
 946	dfid = v9fs_parent_fid(new_dentry);
 947	newdirfid = clone_fid(dfid);
 948	p9_client_clunk(dfid);
 949
 950	if (IS_ERR(newdirfid)) {
 951		retval = PTR_ERR(newdirfid);
 952		goto clunk_olddir;
 953	}
 954
 955	down_write(&v9ses->rename_sem);
 956	if (v9fs_proto_dotl(v9ses)) {
 957		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 958					    newdirfid, new_dentry->d_name.name);
 959		if (retval == -EOPNOTSUPP)
 960			retval = p9_client_rename(oldfid, newdirfid,
 961						  new_dentry->d_name.name);
 962		if (retval != -EOPNOTSUPP)
 963			goto clunk_newdir;
 964	}
 965	if (old_dentry->d_parent != new_dentry->d_parent) {
 966		/*
 967		 * 9P .u can only handle file rename in the same directory
 968		 */
 969
 970		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 971		retval = -EXDEV;
 972		goto clunk_newdir;
 973	}
 974	v9fs_blank_wstat(&wstat);
 975	wstat.muid = v9ses->uname;
 976	wstat.name = new_dentry->d_name.name;
 977	retval = p9_client_wstat(oldfid, &wstat);
 978
 979clunk_newdir:
 980	if (!retval) {
 981		if (new_inode) {
 982			if (S_ISDIR(new_inode->i_mode))
 983				clear_nlink(new_inode);
 984			else
 985				v9fs_dec_count(new_inode);
 986		}
 987		if (S_ISDIR(old_inode->i_mode)) {
 988			if (!new_inode)
 989				inc_nlink(new_dir);
 990			v9fs_dec_count(old_dir);
 991		}
 992		v9fs_invalidate_inode_attr(old_inode);
 993		v9fs_invalidate_inode_attr(old_dir);
 994		v9fs_invalidate_inode_attr(new_dir);
 995
 996		/* successful rename */
 997		d_move(old_dentry, new_dentry);
 998	}
 999	up_write(&v9ses->rename_sem);
1000	p9_client_clunk(newdirfid);
1001
1002clunk_olddir:
1003	p9_client_clunk(olddirfid);
1004
1005done:
1006	p9_client_clunk(oldfid);
1007	return retval;
1008}
1009
1010/**
1011 * v9fs_vfs_getattr - retrieve file metadata
1012 * @path: Object to query
 
1013 * @stat: metadata structure to populate
1014 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
1015 * @flags: AT_STATX_xxx setting
1016 *
1017 */
1018
1019static int
1020v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
1021		 struct kstat *stat, u32 request_mask, unsigned int flags)
1022{
1023	struct dentry *dentry = path->dentry;
1024	struct v9fs_session_info *v9ses;
1025	struct p9_fid *fid;
1026	struct p9_wstat *st;
1027
1028	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1029	v9ses = v9fs_dentry2v9ses(dentry);
1030	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1031		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1032		return 0;
1033	}
1034	fid = v9fs_fid_lookup(dentry);
1035	if (IS_ERR(fid))
1036		return PTR_ERR(fid);
1037
1038	st = p9_client_stat(fid);
1039	p9_client_clunk(fid);
1040	if (IS_ERR(st))
1041		return PTR_ERR(st);
1042
1043	v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1044	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1045
1046	p9stat_free(st);
1047	kfree(st);
1048	return 0;
1049}
1050
1051/**
1052 * v9fs_vfs_setattr - set file metadata
1053 * @dentry: file whose metadata to set
1054 * @iattr: metadata assignment structure
1055 *
1056 */
1057
1058static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
1059			    struct dentry *dentry, struct iattr *iattr)
1060{
1061	int retval, use_dentry = 0;
1062	struct v9fs_session_info *v9ses;
1063	struct p9_fid *fid = NULL;
1064	struct p9_wstat wstat;
1065
1066	p9_debug(P9_DEBUG_VFS, "\n");
1067	retval = setattr_prepare(&init_user_ns, dentry, iattr);
1068	if (retval)
1069		return retval;
1070
1071	retval = -EPERM;
1072	v9ses = v9fs_dentry2v9ses(dentry);
1073	if (iattr->ia_valid & ATTR_FILE) {
1074		fid = iattr->ia_file->private_data;
1075		WARN_ON(!fid);
1076	}
1077	if (!fid) {
1078		fid = v9fs_fid_lookup(dentry);
1079		use_dentry = 1;
1080	}
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 (d_is_reg(dentry))
1107		filemap_write_and_wait(d_inode(dentry)->i_mapping);
1108
1109	retval = p9_client_wstat(fid, &wstat);
1110
1111	if (use_dentry)
1112		p9_client_clunk(fid);
1113
1114	if (retval < 0)
1115		return retval;
1116
1117	if ((iattr->ia_valid & ATTR_SIZE) &&
1118	    iattr->ia_size != i_size_read(d_inode(dentry)))
1119		truncate_setsize(d_inode(dentry), iattr->ia_size);
1120
1121	v9fs_invalidate_inode_attr(d_inode(dentry));
1122
1123	setattr_copy(&init_user_ns, d_inode(dentry), iattr);
1124	mark_inode_dirty(d_inode(dentry));
1125	return 0;
1126}
1127
1128/**
1129 * v9fs_stat2inode - populate an inode structure with mistat info
1130 * @stat: Plan 9 metadata (mistat) structure
1131 * @inode: inode to populate
1132 * @sb: superblock of filesystem
1133 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1134 *
1135 */
1136
1137void
1138v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1139		 struct super_block *sb, unsigned int flags)
1140{
1141	umode_t mode;
 
 
 
1142	struct v9fs_session_info *v9ses = sb->s_fs_info;
1143	struct v9fs_inode *v9inode = V9FS_I(inode);
1144
1145	set_nlink(inode, 1);
1146
1147	inode->i_atime.tv_sec = stat->atime;
1148	inode->i_mtime.tv_sec = stat->mtime;
1149	inode->i_ctime.tv_sec = stat->mtime;
1150
1151	inode->i_uid = v9ses->dfltuid;
1152	inode->i_gid = v9ses->dfltgid;
1153
1154	if (v9fs_proto_dotu(v9ses)) {
1155		inode->i_uid = stat->n_uid;
1156		inode->i_gid = stat->n_gid;
1157	}
1158	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1159		if (v9fs_proto_dotu(v9ses)) {
1160			unsigned int i_nlink;
1161			/*
1162			 * Hadlink support got added later to the .u extension.
1163			 * So there can be a server out there that doesn't
1164			 * support this even with .u extension. That would
1165			 * just leave us with stat->extension being an empty
1166			 * string, though.
1167			 */
 
1168			/* HARDLINKCOUNT %u */
1169			if (sscanf(stat->extension,
1170				   " HARDLINKCOUNT %u", &i_nlink) == 1)
1171				set_nlink(inode, i_nlink);
1172		}
1173	}
1174	mode = p9mode2perm(v9ses, stat);
1175	mode |= inode->i_mode & ~S_IALLUGO;
1176	inode->i_mode = mode;
 
1177
1178	if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1179		v9fs_i_size_write(inode, stat->length);
1180	/* not real number of blocks, but 512 byte ones ... */
1181	inode->i_blocks = (stat->length + 512 - 1) >> 9;
1182	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1183}
1184
1185/**
1186 * v9fs_qid2ino - convert qid into inode number
1187 * @qid: qid to hash
1188 *
1189 * BUG: potential for inode number collisions?
1190 */
1191
1192ino_t v9fs_qid2ino(struct p9_qid *qid)
1193{
1194	u64 path = qid->path + 2;
1195	ino_t i = 0;
1196
1197	if (sizeof(ino_t) == sizeof(path))
1198		memcpy(&i, &path, sizeof(ino_t));
1199	else
1200		i = (ino_t) (path ^ (path >> 32));
1201
1202	return i;
1203}
1204
1205/**
1206 * v9fs_vfs_get_link - follow a symlink path
1207 * @dentry: dentry for symlink
1208 * @inode: inode for symlink
1209 * @done: delayed call for when we are done with the return value
1210 */
1211
1212static const char *v9fs_vfs_get_link(struct dentry *dentry,
1213				     struct inode *inode,
1214				     struct delayed_call *done)
1215{
1216	struct v9fs_session_info *v9ses;
1217	struct p9_fid *fid;
1218	struct p9_wstat *st;
1219	char *res;
1220
1221	if (!dentry)
1222		return ERR_PTR(-ECHILD);
1223
1224	v9ses = v9fs_dentry2v9ses(dentry);
1225	fid = v9fs_fid_lookup(dentry);
1226	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1227
1228	if (IS_ERR(fid))
1229		return ERR_CAST(fid);
1230
1231	if (!v9fs_proto_dotu(v9ses))
1232		return ERR_PTR(-EBADF);
1233
1234	st = p9_client_stat(fid);
1235	p9_client_clunk(fid);
1236	if (IS_ERR(st))
1237		return ERR_CAST(st);
1238
1239	if (!(st->mode & P9_DMSYMLINK)) {
1240		p9stat_free(st);
1241		kfree(st);
1242		return ERR_PTR(-EINVAL);
1243	}
1244	res = st->extension;
1245	st->extension = NULL;
1246	if (strlen(res) >= PATH_MAX)
1247		res[PATH_MAX - 1] = '\0';
1248
1249	p9stat_free(st);
1250	kfree(st);
1251	set_delayed_call(done, kfree_link, res);
1252	return res;
1253}
1254
1255/**
1256 * v9fs_vfs_mkspecial - create a special file
1257 * @dir: inode to create special file in
1258 * @dentry: dentry to create
1259 * @perm: mode to create special file
1260 * @extension: 9p2000.u format extension string representing special file
1261 *
1262 */
1263
1264static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1265	u32 perm, const char *extension)
1266{
1267	struct p9_fid *fid;
1268	struct v9fs_session_info *v9ses;
1269
1270	v9ses = v9fs_inode2v9ses(dir);
1271	if (!v9fs_proto_dotu(v9ses)) {
1272		p9_debug(P9_DEBUG_ERROR, "not extended\n");
1273		return -EPERM;
1274	}
1275
1276	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1277								P9_OREAD);
1278	if (IS_ERR(fid))
1279		return PTR_ERR(fid);
1280
1281	v9fs_invalidate_inode_attr(dir);
1282	p9_client_clunk(fid);
1283	return 0;
1284}
1285
1286/**
1287 * v9fs_vfs_symlink - helper function to create symlinks
1288 * @dir: directory inode containing symlink
1289 * @dentry: dentry for symlink
1290 * @symname: symlink data
1291 *
1292 * See Also: 9P2000.u RFC for more information
1293 *
1294 */
1295
1296static int
1297v9fs_vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
1298		 struct dentry *dentry, const char *symname)
1299{
1300	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1301		 dir->i_ino, dentry, symname);
1302
1303	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1304}
1305
1306#define U32_MAX_DIGITS 10
1307
1308/**
1309 * v9fs_vfs_link - create a hardlink
1310 * @old_dentry: dentry for file to link to
1311 * @dir: inode destination for new link
1312 * @dentry: dentry for link
1313 *
1314 */
1315
1316static int
1317v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1318	      struct dentry *dentry)
1319{
1320	int retval;
1321	char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1322	struct p9_fid *oldfid;
1323
1324	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1325		 dir->i_ino, dentry, old_dentry);
1326
1327	oldfid = v9fs_fid_clone(old_dentry);
1328	if (IS_ERR(oldfid))
1329		return PTR_ERR(oldfid);
1330
1331	sprintf(name, "%d\n", oldfid->fid);
1332	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1333	if (!retval) {
1334		v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1335		v9fs_invalidate_inode_attr(dir);
1336	}
1337	p9_client_clunk(oldfid);
1338	return retval;
1339}
1340
1341/**
1342 * v9fs_vfs_mknod - create a special file
1343 * @dir: inode destination for new link
1344 * @dentry: dentry for file
1345 * @mode: mode for creation
1346 * @rdev: device associated with special file
1347 *
1348 */
1349
1350static int
1351v9fs_vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
1352	       struct dentry *dentry, umode_t mode, dev_t rdev)
1353{
1354	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1355	int retval;
1356	char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1357	u32 perm;
1358
1359	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
1360		 dir->i_ino, dentry, mode,
1361		 MAJOR(rdev), MINOR(rdev));
1362
1363	/* build extension */
1364	if (S_ISBLK(mode))
1365		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1366	else if (S_ISCHR(mode))
1367		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1368	else
1369		*name = 0;
1370
1371	perm = unixmode2p9mode(v9ses, mode);
1372	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1373
1374	return retval;
1375}
1376
1377int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1378{
1379	int umode;
1380	dev_t rdev;
 
1381	struct p9_wstat *st;
1382	struct v9fs_session_info *v9ses;
1383	unsigned int flags;
1384
1385	v9ses = v9fs_inode2v9ses(inode);
1386	st = p9_client_stat(fid);
1387	if (IS_ERR(st))
1388		return PTR_ERR(st);
1389	/*
1390	 * Don't update inode if the file type is different
1391	 */
1392	umode = p9mode2unixmode(v9ses, st, &rdev);
1393	if (inode_wrong_type(inode, umode))
1394		goto out;
1395
 
1396	/*
1397	 * We don't want to refresh inode->i_size,
1398	 * because we may have cached data
1399	 */
1400	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1401		V9FS_STAT2INODE_KEEP_ISIZE : 0;
1402	v9fs_stat2inode(st, inode, inode->i_sb, flags);
 
 
1403out:
1404	p9stat_free(st);
1405	kfree(st);
1406	return 0;
1407}
1408
1409static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1410	.create = v9fs_vfs_create,
1411	.lookup = v9fs_vfs_lookup,
1412	.atomic_open = v9fs_vfs_atomic_open,
1413	.symlink = v9fs_vfs_symlink,
1414	.link = v9fs_vfs_link,
1415	.unlink = v9fs_vfs_unlink,
1416	.mkdir = v9fs_vfs_mkdir,
1417	.rmdir = v9fs_vfs_rmdir,
1418	.mknod = v9fs_vfs_mknod,
1419	.rename = v9fs_vfs_rename,
1420	.getattr = v9fs_vfs_getattr,
1421	.setattr = v9fs_vfs_setattr,
1422};
1423
1424static const struct inode_operations v9fs_dir_inode_operations = {
1425	.create = v9fs_vfs_create,
1426	.lookup = v9fs_vfs_lookup,
1427	.atomic_open = v9fs_vfs_atomic_open,
1428	.unlink = v9fs_vfs_unlink,
1429	.mkdir = v9fs_vfs_mkdir,
1430	.rmdir = v9fs_vfs_rmdir,
1431	.mknod = v9fs_vfs_mknod,
1432	.rename = v9fs_vfs_rename,
1433	.getattr = v9fs_vfs_getattr,
1434	.setattr = v9fs_vfs_setattr,
1435};
1436
1437static const struct inode_operations v9fs_file_inode_operations = {
1438	.getattr = v9fs_vfs_getattr,
1439	.setattr = v9fs_vfs_setattr,
1440};
1441
1442static const struct inode_operations v9fs_symlink_inode_operations = {
 
1443	.get_link = v9fs_vfs_get_link,
1444	.getattr = v9fs_vfs_getattr,
1445	.setattr = v9fs_vfs_setattr,
1446};
1447