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v3.5.6
 
   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		strncpy(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 (uflags & O_TRUNC)
 196		ret |= P9_OTRUNC;
 197
 198	if (extended) {
 199		if (uflags & O_EXCL)
 200			ret |= P9_OEXCL;
 201
 202		if (uflags & O_APPEND)
 203			ret |= P9_OAPPEND;
 204	}
 205
 206	return ret;
 207}
 208
 209/**
 210 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 211 * @wstat: structure to initialize
 212 *
 213 */
 214
 215void
 216v9fs_blank_wstat(struct p9_wstat *wstat)
 217{
 218	wstat->type = ~0;
 219	wstat->dev = ~0;
 220	wstat->qid.type = ~0;
 221	wstat->qid.version = ~0;
 222	*((long long *)&wstat->qid.path) = ~0;
 223	wstat->mode = ~0;
 224	wstat->atime = ~0;
 225	wstat->mtime = ~0;
 226	wstat->length = ~0;
 227	wstat->name = NULL;
 228	wstat->uid = NULL;
 229	wstat->gid = NULL;
 230	wstat->muid = NULL;
 231	wstat->n_uid = ~0;
 232	wstat->n_gid = ~0;
 233	wstat->n_muid = ~0;
 234	wstat->extension = NULL;
 235}
 236
 237/**
 238 * v9fs_alloc_inode - helper function to allocate an inode
 239 *
 240 */
 241struct inode *v9fs_alloc_inode(struct super_block *sb)
 242{
 243	struct v9fs_inode *v9inode;
 244	v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 245							GFP_KERNEL);
 246	if (!v9inode)
 247		return NULL;
 248#ifdef CONFIG_9P_FSCACHE
 249	v9inode->fscache = NULL;
 250	spin_lock_init(&v9inode->fscache_lock);
 251#endif
 252	v9inode->writeback_fid = NULL;
 253	v9inode->cache_validity = 0;
 254	mutex_init(&v9inode->v_mutex);
 255	return &v9inode->vfs_inode;
 256}
 257
 258/**
 259 * v9fs_destroy_inode - destroy an inode
 260 *
 261 */
 262
 263static void v9fs_i_callback(struct rcu_head *head)
 264{
 265	struct inode *inode = container_of(head, struct inode, i_rcu);
 266	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 267}
 268
 269void v9fs_destroy_inode(struct inode *inode)
 
 
 
 270{
 271	call_rcu(&inode->i_rcu, v9fs_i_callback);
 
 272}
 273
 274int v9fs_init_inode(struct v9fs_session_info *v9ses,
 275		    struct inode *inode, umode_t mode, dev_t rdev)
 276{
 277	int err = 0;
 278
 279	inode_init_owner(inode, NULL, mode);
 280	inode->i_blocks = 0;
 281	inode->i_rdev = rdev;
 282	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 283	inode->i_mapping->a_ops = &v9fs_addr_operations;
 
 284
 285	switch (mode & S_IFMT) {
 286	case S_IFIFO:
 287	case S_IFBLK:
 288	case S_IFCHR:
 289	case S_IFSOCK:
 290		if (v9fs_proto_dotl(v9ses)) {
 291			inode->i_op = &v9fs_file_inode_operations_dotl;
 292		} else if (v9fs_proto_dotu(v9ses)) {
 293			inode->i_op = &v9fs_file_inode_operations;
 294		} else {
 295			p9_debug(P9_DEBUG_ERROR,
 296				 "special files without extended mode\n");
 297			err = -EINVAL;
 298			goto error;
 299		}
 300		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 301		break;
 302	case S_IFREG:
 303		if (v9fs_proto_dotl(v9ses)) {
 304			inode->i_op = &v9fs_file_inode_operations_dotl;
 305			if (v9ses->cache)
 306				inode->i_fop =
 307					&v9fs_cached_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)
 313				inode->i_fop = &v9fs_cached_file_operations;
 314			else
 315				inode->i_fop = &v9fs_file_operations;
 316		}
 317
 318		break;
 319	case S_IFLNK:
 320		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 321			p9_debug(P9_DEBUG_ERROR,
 322				 "extended modes used with legacy protocol\n");
 323			err = -EINVAL;
 324			goto error;
 325		}
 326
 327		if (v9fs_proto_dotl(v9ses))
 328			inode->i_op = &v9fs_symlink_inode_operations_dotl;
 329		else
 330			inode->i_op = &v9fs_symlink_inode_operations;
 331
 332		break;
 333	case S_IFDIR:
 334		inc_nlink(inode);
 335		if (v9fs_proto_dotl(v9ses))
 336			inode->i_op = &v9fs_dir_inode_operations_dotl;
 337		else if (v9fs_proto_dotu(v9ses))
 338			inode->i_op = &v9fs_dir_inode_operations_dotu;
 339		else
 340			inode->i_op = &v9fs_dir_inode_operations;
 341
 342		if (v9fs_proto_dotl(v9ses))
 343			inode->i_fop = &v9fs_dir_operations_dotl;
 344		else
 345			inode->i_fop = &v9fs_dir_operations;
 346
 347		break;
 348	default:
 349		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 350			 mode, mode & S_IFMT);
 351		err = -EINVAL;
 352		goto error;
 353	}
 354error:
 355	return err;
 356
 357}
 358
 359/**
 360 * v9fs_get_inode - helper function to setup an inode
 361 * @sb: superblock
 362 * @mode: mode to setup inode with
 363 *
 364 */
 365
 366struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 367{
 368	int err;
 369	struct inode *inode;
 370	struct v9fs_session_info *v9ses = sb->s_fs_info;
 371
 372	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 373
 374	inode = new_inode(sb);
 375	if (!inode) {
 376		pr_warn("%s (%d): Problem allocating inode\n",
 377			__func__, task_pid_nr(current));
 378		return ERR_PTR(-ENOMEM);
 379	}
 380	err = v9fs_init_inode(v9ses, inode, mode, rdev);
 381	if (err) {
 382		iput(inode);
 383		return ERR_PTR(err);
 384	}
 
 385	return inode;
 386}
 387
 388/*
 389static struct v9fs_fid*
 390v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 391{
 392	int err;
 393	int nfid;
 394	struct v9fs_fid *ret;
 395	struct v9fs_fcall *fcall;
 396
 397	nfid = v9fs_get_idpool(&v9ses->fidpool);
 398	if (nfid < 0) {
 399		eprintk(KERN_WARNING, "no free fids available\n");
 400		return ERR_PTR(-ENOSPC);
 401	}
 402
 403	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 404		&fcall);
 405
 406	if (err < 0) {
 407		if (fcall && fcall->id == RWALK)
 408			goto clunk_fid;
 409
 410		PRINT_FCALL_ERROR("walk error", fcall);
 411		v9fs_put_idpool(nfid, &v9ses->fidpool);
 412		goto error;
 413	}
 414
 415	kfree(fcall);
 416	fcall = NULL;
 417	ret = v9fs_fid_create(v9ses, nfid);
 418	if (!ret) {
 419		err = -ENOMEM;
 420		goto clunk_fid;
 421	}
 422
 423	err = v9fs_fid_insert(ret, dentry);
 424	if (err < 0) {
 425		v9fs_fid_destroy(ret);
 426		goto clunk_fid;
 427	}
 428
 429	return ret;
 430
 431clunk_fid:
 432	v9fs_t_clunk(v9ses, nfid);
 433
 434error:
 435	kfree(fcall);
 436	return ERR_PTR(err);
 437}
 438*/
 439
 440
 441/**
 442 * v9fs_clear_inode - release an inode
 443 * @inode: inode to release
 444 *
 445 */
 446void v9fs_evict_inode(struct inode *inode)
 447{
 448	struct v9fs_inode *v9inode = V9FS_I(inode);
 
 
 
 
 
 
 449
 450	truncate_inode_pages(inode->i_mapping, 0);
 451	clear_inode(inode);
 452	filemap_fdatawrite(inode->i_mapping);
 453
 454#ifdef CONFIG_9P_FSCACHE
 455	v9fs_cache_inode_put_cookie(inode);
 456#endif
 457	/* clunk the fid stashed in writeback_fid */
 458	if (v9inode->writeback_fid) {
 459		p9_client_clunk(v9inode->writeback_fid);
 460		v9inode->writeback_fid = NULL;
 461	}
 462}
 463
 464static int v9fs_test_inode(struct inode *inode, void *data)
 465{
 466	int umode;
 467	dev_t rdev;
 468	struct v9fs_inode *v9inode = V9FS_I(inode);
 469	struct p9_wstat *st = (struct p9_wstat *)data;
 470	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 471
 472	umode = p9mode2unixmode(v9ses, st, &rdev);
 473	/* don't match inode of different type */
 474	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 475		return 0;
 476
 477	/* compare qid details */
 478	if (memcmp(&v9inode->qid.version,
 479		   &st->qid.version, sizeof(v9inode->qid.version)))
 480		return 0;
 481
 482	if (v9inode->qid.type != st->qid.type)
 483		return 0;
 
 
 
 484	return 1;
 485}
 486
 487static int v9fs_test_new_inode(struct inode *inode, void *data)
 488{
 489	return 0;
 490}
 491
 492static int v9fs_set_inode(struct inode *inode,  void *data)
 493{
 494	struct v9fs_inode *v9inode = V9FS_I(inode);
 495	struct p9_wstat *st = (struct p9_wstat *)data;
 496
 497	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 498	return 0;
 499}
 500
 501static struct inode *v9fs_qid_iget(struct super_block *sb,
 502				   struct p9_qid *qid,
 503				   struct p9_wstat *st,
 504				   int new)
 505{
 506	dev_t rdev;
 507	int retval;
 508	umode_t umode;
 509	unsigned long i_ino;
 510	struct inode *inode;
 511	struct v9fs_session_info *v9ses = sb->s_fs_info;
 512	int (*test)(struct inode *, void *);
 513
 514	if (new)
 515		test = v9fs_test_new_inode;
 516	else
 517		test = v9fs_test_inode;
 518
 519	i_ino = v9fs_qid2ino(qid);
 520	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 521	if (!inode)
 522		return ERR_PTR(-ENOMEM);
 523	if (!(inode->i_state & I_NEW))
 524		return inode;
 525	/*
 526	 * initialize the inode with the stat info
 527	 * FIXME!! we may need support for stale inodes
 528	 * later.
 529	 */
 530	inode->i_ino = i_ino;
 531	umode = p9mode2unixmode(v9ses, st, &rdev);
 532	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 533	if (retval)
 534		goto error;
 535
 536	v9fs_stat2inode(st, inode, sb);
 537#ifdef CONFIG_9P_FSCACHE
 538	v9fs_cache_inode_get_cookie(inode);
 539#endif
 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		err = v9fs_fid_add(dentry, fid);
 699		if (err < 0)
 700			goto error;
 701		d_instantiate(dentry, inode);
 702	}
 
 703	return ofid;
 704error:
 705	if (ofid)
 706		p9_client_clunk(ofid);
 707
 708	if (fid)
 709		p9_client_clunk(fid);
 710
 711	return ERR_PTR(err);
 712}
 713
 714/**
 715 * v9fs_vfs_create - VFS hook to create files
 716 * @dir: directory inode that is being created
 717 * @dentry:  dentry that is being deleted
 718 * @mode: create permissions
 719 * @nd: path information
 
 
 
 
 720 *
 721 */
 722
 723static int
 724v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 725		struct nameidata *nd)
 726{
 727	int err;
 728	u32 perm;
 729	int flags;
 730	struct file *filp;
 731	struct v9fs_inode *v9inode;
 732	struct v9fs_session_info *v9ses;
 733	struct p9_fid *fid, *inode_fid;
 734
 735	err = 0;
 736	fid = NULL;
 737	v9ses = v9fs_inode2v9ses(dir);
 738	perm = unixmode2p9mode(v9ses, mode);
 739	if (nd)
 740		flags = nd->intent.open.flags;
 741	else
 742		flags = O_RDWR;
 743
 744	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 745				v9fs_uflags2omode(flags,
 746						v9fs_proto_dotu(v9ses)));
 747	if (IS_ERR(fid)) {
 748		err = PTR_ERR(fid);
 749		fid = NULL;
 750		goto error;
 751	}
 752
 753	v9fs_invalidate_inode_attr(dir);
 754	/* if we are opening a file, assign the open fid to the file */
 755	if (nd) {
 756		v9inode = V9FS_I(dentry->d_inode);
 757		mutex_lock(&v9inode->v_mutex);
 758		if (v9ses->cache && !v9inode->writeback_fid &&
 759		    ((flags & O_ACCMODE) != O_RDONLY)) {
 760			/*
 761			 * clone a fid and add it to writeback_fid
 762			 * we do it during open time instead of
 763			 * page dirty time via write_begin/page_mkwrite
 764			 * because we want write after unlink usecase
 765			 * to work.
 766			 */
 767			inode_fid = v9fs_writeback_fid(dentry);
 768			if (IS_ERR(inode_fid)) {
 769				err = PTR_ERR(inode_fid);
 770				mutex_unlock(&v9inode->v_mutex);
 771				goto error;
 772			}
 773			v9inode->writeback_fid = (void *) inode_fid;
 774		}
 775		mutex_unlock(&v9inode->v_mutex);
 776		filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
 777		if (IS_ERR(filp)) {
 778			err = PTR_ERR(filp);
 779			goto error;
 780		}
 781
 782		filp->private_data = fid;
 783#ifdef CONFIG_9P_FSCACHE
 784		if (v9ses->cache)
 785			v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
 786#endif
 787	} else
 788		p9_client_clunk(fid);
 789
 790	return 0;
 791
 792error:
 793	if (fid)
 794		p9_client_clunk(fid);
 795
 796	return err;
 797}
 798
 799/**
 800 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 
 801 * @dir:  inode that is being unlinked
 802 * @dentry: dentry that is being unlinked
 803 * @mode: mode for new directory
 804 *
 805 */
 806
 807static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 
 808{
 809	int err;
 810	u32 perm;
 811	struct p9_fid *fid;
 812	struct v9fs_session_info *v9ses;
 813
 814	p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 815	err = 0;
 816	v9ses = v9fs_inode2v9ses(dir);
 817	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 818	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 819	if (IS_ERR(fid)) {
 820		err = PTR_ERR(fid);
 821		fid = NULL;
 822	} else {
 823		inc_nlink(dir);
 824		v9fs_invalidate_inode_attr(dir);
 825	}
 826
 827	if (fid)
 828		p9_client_clunk(fid);
 829
 830	return err;
 831}
 832
 833/**
 834 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 835 * @dir:  inode that is being walked from
 836 * @dentry: dentry that is being walked to?
 837 * @nameidata: path data
 838 *
 839 */
 840
 841struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 842				      struct nameidata *nameidata)
 843{
 844	struct dentry *res;
 845	struct super_block *sb;
 846	struct v9fs_session_info *v9ses;
 847	struct p9_fid *dfid, *fid;
 848	struct inode *inode;
 849	char *name;
 850	int result = 0;
 851
 852	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 853		 dir, dentry->d_name.name, dentry, nameidata);
 854
 855	if (dentry->d_name.len > NAME_MAX)
 856		return ERR_PTR(-ENAMETOOLONG);
 857
 858	sb = dir->i_sb;
 859	v9ses = v9fs_inode2v9ses(dir);
 860	/* We can walk d_parent because we hold the dir->i_mutex */
 861	dfid = v9fs_fid_lookup(dentry->d_parent);
 862	if (IS_ERR(dfid))
 863		return ERR_CAST(dfid);
 864
 865	name = (char *) dentry->d_name.name;
 866	fid = p9_client_walk(dfid, 1, &name, 1);
 867	if (IS_ERR(fid)) {
 868		result = PTR_ERR(fid);
 869		if (result == -ENOENT) {
 870			inode = NULL;
 871			goto inst_out;
 872		}
 873
 874		return ERR_PTR(result);
 875	}
 876	/*
 877	 * Make sure we don't use a wrong inode due to parallel
 878	 * unlink. For cached mode create calls request for new
 879	 * inode. But with cache disabled, lookup should do this.
 880	 */
 881	if (v9ses->cache)
 
 
 
 
 
 
 
 882		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 883	else
 884		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 885	if (IS_ERR(inode)) {
 886		result = PTR_ERR(inode);
 887		inode = NULL;
 888		goto error;
 889	}
 890	result = v9fs_fid_add(dentry, fid);
 891	if (result < 0)
 892		goto error_iput;
 893inst_out:
 894	/*
 895	 * If we had a rename on the server and a parallel lookup
 896	 * for the new name, then make sure we instantiate with
 897	 * the new name. ie look up for a/b, while on server somebody
 898	 * moved b under k and client parallely did a lookup for
 899	 * k/b.
 900	 */
 901	res = d_materialise_unique(dentry, inode);
 902	if (!IS_ERR(res))
 903		return res;
 904	result = PTR_ERR(res);
 905error_iput:
 906	iput(inode);
 907error:
 908	p9_client_clunk(fid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 909
 910	return ERR_PTR(result);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 911}
 912
 913/**
 914 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 915 * @i:  inode that is being unlinked
 916 * @d: dentry that is being unlinked
 917 *
 918 */
 919
 920int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 921{
 922	return v9fs_remove(i, d, 0);
 923}
 924
 925/**
 926 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 927 * @i:  inode that is being unlinked
 928 * @d: dentry that is being unlinked
 929 *
 930 */
 931
 932int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 933{
 934	return v9fs_remove(i, d, AT_REMOVEDIR);
 935}
 936
 937/**
 938 * v9fs_vfs_rename - VFS hook to rename an inode
 
 939 * @old_dir:  old dir inode
 940 * @old_dentry: old dentry
 941 * @new_dir: new dir inode
 942 * @new_dentry: new dentry
 
 943 *
 944 */
 945
 946int
 947v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 948		struct inode *new_dir, struct dentry *new_dentry)
 
 949{
 950	int retval;
 951	struct inode *old_inode;
 952	struct inode *new_inode;
 953	struct v9fs_session_info *v9ses;
 954	struct p9_fid *oldfid;
 955	struct p9_fid *olddirfid;
 956	struct p9_fid *newdirfid;
 957	struct p9_wstat wstat;
 958
 
 
 
 959	p9_debug(P9_DEBUG_VFS, "\n");
 960	retval = 0;
 961	old_inode = old_dentry->d_inode;
 962	new_inode = new_dentry->d_inode;
 963	v9ses = v9fs_inode2v9ses(old_inode);
 964	oldfid = v9fs_fid_lookup(old_dentry);
 965	if (IS_ERR(oldfid))
 966		return PTR_ERR(oldfid);
 967
 968	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 
 
 
 
 969	if (IS_ERR(olddirfid)) {
 970		retval = PTR_ERR(olddirfid);
 971		goto done;
 972	}
 973
 974	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 
 
 
 
 975	if (IS_ERR(newdirfid)) {
 976		retval = PTR_ERR(newdirfid);
 977		goto clunk_olddir;
 978	}
 979
 980	down_write(&v9ses->rename_sem);
 981	if (v9fs_proto_dotl(v9ses)) {
 982		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 983					    newdirfid, new_dentry->d_name.name);
 984		if (retval == -EOPNOTSUPP)
 985			retval = p9_client_rename(oldfid, newdirfid,
 986						  new_dentry->d_name.name);
 987		if (retval != -EOPNOTSUPP)
 988			goto clunk_newdir;
 989	}
 990	if (old_dentry->d_parent != new_dentry->d_parent) {
 991		/*
 992		 * 9P .u can only handle file rename in the same directory
 993		 */
 994
 995		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 996		retval = -EXDEV;
 997		goto clunk_newdir;
 998	}
 999	v9fs_blank_wstat(&wstat);
1000	wstat.muid = v9ses->uname;
1001	wstat.name = (char *) new_dentry->d_name.name;
1002	retval = p9_client_wstat(oldfid, &wstat);
1003
1004clunk_newdir:
1005	if (!retval) {
1006		if (new_inode) {
1007			if (S_ISDIR(new_inode->i_mode))
1008				clear_nlink(new_inode);
1009			else
1010				drop_nlink(new_inode);
1011		}
1012		if (S_ISDIR(old_inode->i_mode)) {
1013			if (!new_inode)
1014				inc_nlink(new_dir);
1015			drop_nlink(old_dir);
1016		}
1017		v9fs_invalidate_inode_attr(old_inode);
1018		v9fs_invalidate_inode_attr(old_dir);
1019		v9fs_invalidate_inode_attr(new_dir);
1020
1021		/* successful rename */
1022		d_move(old_dentry, new_dentry);
1023	}
1024	up_write(&v9ses->rename_sem);
1025	p9_client_clunk(newdirfid);
1026
1027clunk_olddir:
1028	p9_client_clunk(olddirfid);
1029
1030done:
 
 
 
1031	return retval;
1032}
1033
1034/**
1035 * v9fs_vfs_getattr - retrieve file metadata
1036 * @mnt: mount information
1037 * @dentry: file to get attributes on
1038 * @stat: metadata structure to populate
 
 
1039 *
1040 */
1041
1042static int
1043v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1044		 struct kstat *stat)
1045{
1046	int err;
 
1047	struct v9fs_session_info *v9ses;
1048	struct p9_fid *fid;
1049	struct p9_wstat *st;
1050
1051	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1052	err = -EPERM;
1053	v9ses = v9fs_dentry2v9ses(dentry);
1054	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1055		generic_fillattr(dentry->d_inode, stat);
1056		return 0;
 
 
 
 
 
 
 
 
1057	}
1058	fid = v9fs_fid_lookup(dentry);
1059	if (IS_ERR(fid))
1060		return PTR_ERR(fid);
1061
1062	st = p9_client_stat(fid);
 
1063	if (IS_ERR(st))
1064		return PTR_ERR(st);
1065
1066	v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1067	generic_fillattr(dentry->d_inode, stat);
1068
1069	p9stat_free(st);
1070	kfree(st);
1071	return 0;
1072}
1073
1074/**
1075 * v9fs_vfs_setattr - set file metadata
 
1076 * @dentry: file whose metadata to set
1077 * @iattr: metadata assignment structure
1078 *
1079 */
1080
1081static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 
1082{
1083	int retval;
 
1084	struct v9fs_session_info *v9ses;
1085	struct p9_fid *fid;
1086	struct p9_wstat wstat;
1087
1088	p9_debug(P9_DEBUG_VFS, "\n");
1089	retval = inode_change_ok(dentry->d_inode, iattr);
1090	if (retval)
1091		return retval;
1092
1093	retval = -EPERM;
1094	v9ses = v9fs_dentry2v9ses(dentry);
1095	fid = v9fs_fid_lookup(dentry);
1096	if(IS_ERR(fid))
 
 
 
 
 
 
 
1097		return PTR_ERR(fid);
1098
1099	v9fs_blank_wstat(&wstat);
1100	if (iattr->ia_valid & ATTR_MODE)
1101		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1102
1103	if (iattr->ia_valid & ATTR_MTIME)
1104		wstat.mtime = iattr->ia_mtime.tv_sec;
1105
1106	if (iattr->ia_valid & ATTR_ATIME)
1107		wstat.atime = iattr->ia_atime.tv_sec;
1108
1109	if (iattr->ia_valid & ATTR_SIZE)
1110		wstat.length = iattr->ia_size;
1111
1112	if (v9fs_proto_dotu(v9ses)) {
1113		if (iattr->ia_valid & ATTR_UID)
1114			wstat.n_uid = iattr->ia_uid;
1115
1116		if (iattr->ia_valid & ATTR_GID)
1117			wstat.n_gid = iattr->ia_gid;
1118	}
1119
1120	/* Write all dirty data */
1121	if (S_ISREG(dentry->d_inode->i_mode))
1122		filemap_write_and_wait(dentry->d_inode->i_mapping);
 
 
 
 
1123
1124	retval = p9_client_wstat(fid, &wstat);
 
 
 
 
1125	if (retval < 0)
1126		return retval;
1127
1128	if ((iattr->ia_valid & ATTR_SIZE) &&
1129	    iattr->ia_size != i_size_read(dentry->d_inode))
1130		truncate_setsize(dentry->d_inode, iattr->ia_size);
 
1131
1132	v9fs_invalidate_inode_attr(dentry->d_inode);
 
 
1133
1134	setattr_copy(dentry->d_inode, iattr);
1135	mark_inode_dirty(dentry->d_inode);
 
 
 
 
 
 
 
1136	return 0;
1137}
1138
1139/**
1140 * v9fs_stat2inode - populate an inode structure with mistat info
1141 * @stat: Plan 9 metadata (mistat) structure
1142 * @inode: inode to populate
1143 * @sb: superblock of filesystem
 
1144 *
1145 */
1146
1147void
1148v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1149	struct super_block *sb)
1150{
1151	umode_t mode;
1152	char ext[32];
1153	char tag_name[14];
1154	unsigned int i_nlink;
1155	struct v9fs_session_info *v9ses = sb->s_fs_info;
1156	struct v9fs_inode *v9inode = V9FS_I(inode);
1157
1158	set_nlink(inode, 1);
1159
1160	inode->i_atime.tv_sec = stat->atime;
1161	inode->i_mtime.tv_sec = stat->mtime;
1162	inode->i_ctime.tv_sec = stat->mtime;
1163
1164	inode->i_uid = v9ses->dfltuid;
1165	inode->i_gid = v9ses->dfltgid;
1166
1167	if (v9fs_proto_dotu(v9ses)) {
1168		inode->i_uid = stat->n_uid;
1169		inode->i_gid = stat->n_gid;
1170	}
1171	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1172		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
 
1173			/*
1174			 * Hadlink support got added later to
1175			 * to the .u extension. So there can be
1176			 * server out there that doesn't support
1177			 * this even with .u extension. So check
1178			 * for non NULL stat->extension
1179			 */
1180			strncpy(ext, stat->extension, sizeof(ext));
1181			/* HARDLINKCOUNT %u */
1182			sscanf(ext, "%13s %u", tag_name, &i_nlink);
1183			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1184				set_nlink(inode, i_nlink);
1185		}
1186	}
1187	mode = p9mode2perm(v9ses, stat);
1188	mode |= inode->i_mode & ~S_IALLUGO;
1189	inode->i_mode = mode;
1190	i_size_write(inode, stat->length);
1191
 
 
 
1192	/* not real number of blocks, but 512 byte ones ... */
1193	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1194	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1195}
1196
1197/**
1198 * v9fs_qid2ino - convert qid into inode number
1199 * @qid: qid to hash
1200 *
1201 * BUG: potential for inode number collisions?
1202 */
1203
1204ino_t v9fs_qid2ino(struct p9_qid *qid)
1205{
1206	u64 path = qid->path + 2;
1207	ino_t i = 0;
1208
1209	if (sizeof(ino_t) == sizeof(path))
1210		memcpy(&i, &path, sizeof(ino_t));
1211	else
1212		i = (ino_t) (path ^ (path >> 32));
1213
1214	return i;
1215}
1216
1217/**
1218 * v9fs_readlink - read a symlink's location (internal version)
1219 * @dentry: dentry for symlink
1220 * @buffer: buffer to load symlink location into
1221 * @buflen: length of buffer
1222 *
1223 */
1224
1225static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 
 
1226{
1227	int retval;
1228
1229	struct v9fs_session_info *v9ses;
1230	struct p9_fid *fid;
1231	struct p9_wstat *st;
 
 
 
 
1232
1233	p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1234	retval = -EPERM;
1235	v9ses = v9fs_dentry2v9ses(dentry);
 
 
 
 
1236	fid = v9fs_fid_lookup(dentry);
1237	if (IS_ERR(fid))
1238		return PTR_ERR(fid);
1239
1240	if (!v9fs_proto_dotu(v9ses))
1241		return -EBADF;
1242
1243	st = p9_client_stat(fid);
 
1244	if (IS_ERR(st))
1245		return PTR_ERR(st);
1246
1247	if (!(st->mode & P9_DMSYMLINK)) {
1248		retval = -EINVAL;
1249		goto done;
1250	}
1251
1252	/* copy extension buffer into buffer */
1253	strncpy(buffer, st->extension, buflen);
1254
1255	p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n",
1256		 dentry->d_name.name, st->extension, buffer);
1257
1258	retval = strnlen(buffer, buflen);
1259done:
1260	p9stat_free(st);
1261	kfree(st);
1262	return retval;
1263}
1264
1265/**
1266 * v9fs_vfs_follow_link - follow a symlink path
1267 * @dentry: dentry for symlink
1268 * @nd: nameidata
1269 *
1270 */
1271
1272static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1273{
1274	int len = 0;
1275	char *link = __getname();
1276
1277	p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
1278
1279	if (!link)
1280		link = ERR_PTR(-ENOMEM);
1281	else {
1282		len = v9fs_readlink(dentry, link, PATH_MAX);
1283
1284		if (len < 0) {
1285			__putname(link);
1286			link = ERR_PTR(len);
1287		} else
1288			link[min(len, PATH_MAX-1)] = 0;
1289	}
1290	nd_set_link(nd, link);
1291
1292	return NULL;
1293}
1294
1295/**
1296 * v9fs_vfs_put_link - release a symlink path
1297 * @dentry: dentry for symlink
1298 * @nd: nameidata
1299 * @p: unused
1300 *
1301 */
1302
1303void
1304v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1305{
1306	char *s = nd_get_link(nd);
1307
1308	p9_debug(P9_DEBUG_VFS, " %s %s\n",
1309		 dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
1310	if (!IS_ERR(s))
1311		__putname(s);
1312}
1313
1314/**
1315 * v9fs_vfs_mkspecial - create a special file
1316 * @dir: inode to create special file in
1317 * @dentry: dentry to create
1318 * @mode: mode to create special file
1319 * @extension: 9p2000.u format extension string representing special file
1320 *
1321 */
1322
1323static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1324	u32 perm, const char *extension)
1325{
1326	struct p9_fid *fid;
1327	struct v9fs_session_info *v9ses;
1328
1329	v9ses = v9fs_inode2v9ses(dir);
1330	if (!v9fs_proto_dotu(v9ses)) {
1331		p9_debug(P9_DEBUG_ERROR, "not extended\n");
1332		return -EPERM;
1333	}
1334
1335	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1336								P9_OREAD);
1337	if (IS_ERR(fid))
1338		return PTR_ERR(fid);
1339
1340	v9fs_invalidate_inode_attr(dir);
1341	p9_client_clunk(fid);
1342	return 0;
1343}
1344
1345/**
1346 * v9fs_vfs_symlink - helper function to create symlinks
 
1347 * @dir: directory inode containing symlink
1348 * @dentry: dentry for symlink
1349 * @symname: symlink data
1350 *
1351 * See Also: 9P2000.u RFC for more information
1352 *
1353 */
1354
1355static int
1356v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
 
1357{
1358	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1359		 dir->i_ino, dentry->d_name.name, symname);
1360
1361	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1362}
1363
 
 
1364/**
1365 * v9fs_vfs_link - create a hardlink
1366 * @old_dentry: dentry for file to link to
1367 * @dir: inode destination for new link
1368 * @dentry: dentry for link
1369 *
1370 */
1371
1372static int
1373v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1374	      struct dentry *dentry)
1375{
1376	int retval;
1377	char *name;
1378	struct p9_fid *oldfid;
1379
1380	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1381		 dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
1382
1383	oldfid = v9fs_fid_clone(old_dentry);
1384	if (IS_ERR(oldfid))
1385		return PTR_ERR(oldfid);
1386
1387	name = __getname();
1388	if (unlikely(!name)) {
1389		retval = -ENOMEM;
1390		goto clunk_fid;
1391	}
1392
1393	sprintf(name, "%d\n", oldfid->fid);
1394	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1395	__putname(name);
1396	if (!retval) {
1397		v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1398		v9fs_invalidate_inode_attr(dir);
1399	}
1400clunk_fid:
1401	p9_client_clunk(oldfid);
1402	return retval;
1403}
1404
1405/**
1406 * v9fs_vfs_mknod - create a special file
 
1407 * @dir: inode destination for new link
1408 * @dentry: dentry for file
1409 * @mode: mode for creation
1410 * @rdev: device associated with special file
1411 *
1412 */
1413
1414static int
1415v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
 
1416{
1417	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1418	int retval;
1419	char *name;
1420	u32 perm;
1421
1422	p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
1423		 dir->i_ino, dentry->d_name.name, mode,
1424		 MAJOR(rdev), MINOR(rdev));
1425
1426	if (!new_valid_dev(rdev))
1427		return -EINVAL;
1428
1429	name = __getname();
1430	if (!name)
1431		return -ENOMEM;
1432	/* build extension */
1433	if (S_ISBLK(mode))
1434		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1435	else if (S_ISCHR(mode))
1436		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1437	else if (S_ISFIFO(mode))
1438		*name = 0;
1439	else if (S_ISSOCK(mode))
1440		*name = 0;
1441	else {
1442		__putname(name);
1443		return -EINVAL;
1444	}
1445
1446	perm = unixmode2p9mode(v9ses, mode);
1447	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1448	__putname(name);
1449
1450	return retval;
1451}
1452
1453int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1454{
1455	int umode;
1456	dev_t rdev;
1457	loff_t i_size;
1458	struct p9_wstat *st;
1459	struct v9fs_session_info *v9ses;
 
1460
1461	v9ses = v9fs_inode2v9ses(inode);
1462	st = p9_client_stat(fid);
1463	if (IS_ERR(st))
1464		return PTR_ERR(st);
1465	/*
1466	 * Don't update inode if the file type is different
1467	 */
1468	umode = p9mode2unixmode(v9ses, st, &rdev);
1469	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1470		goto out;
1471
1472	spin_lock(&inode->i_lock);
1473	/*
1474	 * We don't want to refresh inode->i_size,
1475	 * because we may have cached data
1476	 */
1477	i_size = inode->i_size;
1478	v9fs_stat2inode(st, inode, inode->i_sb);
1479	if (v9ses->cache)
1480		inode->i_size = i_size;
1481	spin_unlock(&inode->i_lock);
1482out:
1483	p9stat_free(st);
1484	kfree(st);
1485	return 0;
1486}
1487
1488static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1489	.create = v9fs_vfs_create,
1490	.lookup = v9fs_vfs_lookup,
 
1491	.symlink = v9fs_vfs_symlink,
1492	.link = v9fs_vfs_link,
1493	.unlink = v9fs_vfs_unlink,
1494	.mkdir = v9fs_vfs_mkdir,
1495	.rmdir = v9fs_vfs_rmdir,
1496	.mknod = v9fs_vfs_mknod,
1497	.rename = v9fs_vfs_rename,
1498	.getattr = v9fs_vfs_getattr,
1499	.setattr = v9fs_vfs_setattr,
1500};
1501
1502static const struct inode_operations v9fs_dir_inode_operations = {
1503	.create = v9fs_vfs_create,
1504	.lookup = v9fs_vfs_lookup,
 
1505	.unlink = v9fs_vfs_unlink,
1506	.mkdir = v9fs_vfs_mkdir,
1507	.rmdir = v9fs_vfs_rmdir,
1508	.mknod = v9fs_vfs_mknod,
1509	.rename = v9fs_vfs_rename,
1510	.getattr = v9fs_vfs_getattr,
1511	.setattr = v9fs_vfs_setattr,
1512};
1513
1514static const struct inode_operations v9fs_file_inode_operations = {
1515	.getattr = v9fs_vfs_getattr,
1516	.setattr = v9fs_vfs_setattr,
1517};
1518
1519static const struct inode_operations v9fs_symlink_inode_operations = {
1520	.readlink = generic_readlink,
1521	.follow_link = v9fs_vfs_follow_link,
1522	.put_link = v9fs_vfs_put_link,
1523	.getattr = v9fs_vfs_getattr,
1524	.setattr = v9fs_vfs_setattr,
1525};
1526
v6.8
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
 
 
   3 * This file contains vfs inode ops for the 9P2000 protocol.
   4 *
   5 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   6 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   7 */
   8
   9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11#include <linux/module.h>
  12#include <linux/errno.h>
  13#include <linux/fs.h>
  14#include <linux/file.h>
  15#include <linux/pagemap.h>
  16#include <linux/stat.h>
  17#include <linux/string.h>
 
  18#include <linux/namei.h>
 
  19#include <linux/sched.h>
  20#include <linux/slab.h>
  21#include <linux/xattr.h>
  22#include <linux/posix_acl.h>
  23#include <net/9p/9p.h>
  24#include <net/9p/client.h>
  25
  26#include "v9fs.h"
  27#include "v9fs_vfs.h"
  28#include "fid.h"
  29#include "cache.h"
  30#include "xattr.h"
  31#include "acl.h"
  32
  33static const struct inode_operations v9fs_dir_inode_operations;
  34static const struct inode_operations v9fs_dir_inode_operations_dotu;
  35static const struct inode_operations v9fs_file_inode_operations;
  36static const struct inode_operations v9fs_symlink_inode_operations;
  37
  38/**
  39 * unixmode2p9mode - convert unix mode bits to plan 9
  40 * @v9ses: v9fs session information
  41 * @mode: mode to convert
  42 *
  43 */
  44
  45static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
  46{
  47	int res;
  48
  49	res = mode & 0777;
  50	if (S_ISDIR(mode))
  51		res |= P9_DMDIR;
  52	if (v9fs_proto_dotu(v9ses)) {
  53		if (v9ses->nodev == 0) {
  54			if (S_ISSOCK(mode))
  55				res |= P9_DMSOCKET;
  56			if (S_ISFIFO(mode))
  57				res |= P9_DMNAMEDPIPE;
  58			if (S_ISBLK(mode))
  59				res |= P9_DMDEVICE;
  60			if (S_ISCHR(mode))
  61				res |= P9_DMDEVICE;
  62		}
  63
  64		if ((mode & S_ISUID) == S_ISUID)
  65			res |= P9_DMSETUID;
  66		if ((mode & S_ISGID) == S_ISGID)
  67			res |= P9_DMSETGID;
  68		if ((mode & S_ISVTX) == S_ISVTX)
  69			res |= P9_DMSETVTX;
  70	}
  71	return res;
  72}
  73
  74/**
  75 * p9mode2perm- convert plan9 mode bits to unix permission bits
  76 * @v9ses: v9fs session information
  77 * @stat: p9_wstat from which mode need to be derived
  78 *
  79 */
  80static int p9mode2perm(struct v9fs_session_info *v9ses,
  81		       struct p9_wstat *stat)
  82{
  83	int res;
  84	int mode = stat->mode;
  85
  86	res = mode & S_IALLUGO;
  87	if (v9fs_proto_dotu(v9ses)) {
  88		if ((mode & P9_DMSETUID) == P9_DMSETUID)
  89			res |= S_ISUID;
  90
  91		if ((mode & P9_DMSETGID) == P9_DMSETGID)
  92			res |= S_ISGID;
  93
  94		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
  95			res |= S_ISVTX;
  96	}
  97	return res;
  98}
  99
 100/**
 101 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 102 * @v9ses: v9fs session information
 103 * @stat: p9_wstat from which mode need to be derived
 104 * @rdev: major number, minor number in case of device files.
 105 *
 106 */
 107static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 108			       struct p9_wstat *stat, dev_t *rdev)
 109{
 110	int res, r;
 111	u32 mode = stat->mode;
 112
 113	*rdev = 0;
 114	res = p9mode2perm(v9ses, stat);
 115
 116	if ((mode & P9_DMDIR) == P9_DMDIR)
 117		res |= S_IFDIR;
 118	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 119		res |= S_IFLNK;
 120	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 121		 && (v9ses->nodev == 0))
 122		res |= S_IFSOCK;
 123	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 124		 && (v9ses->nodev == 0))
 125		res |= S_IFIFO;
 126	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 127		 && (v9ses->nodev == 0)) {
 128		char type = 0;
 129		int major = -1, minor = -1;
 130
 131		r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
 132		if (r != 3) {
 133			p9_debug(P9_DEBUG_ERROR,
 134				 "invalid device string, umode will be bogus: %s\n",
 135				 stat->extension);
 136			return res;
 137		}
 138		switch (type) {
 139		case 'c':
 140			res |= S_IFCHR;
 141			break;
 142		case 'b':
 143			res |= S_IFBLK;
 144			break;
 145		default:
 146			p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 147				 type, stat->extension);
 148		}
 149		*rdev = MKDEV(major, minor);
 150	} else
 151		res |= S_IFREG;
 152
 153	return res;
 154}
 155
 156/**
 157 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 158 * @uflags: flags to convert
 159 * @extended: if .u extensions are active
 160 */
 161
 162int v9fs_uflags2omode(int uflags, int extended)
 163{
 164	int ret;
 165
 
 166	switch (uflags&3) {
 167	default:
 168	case O_RDONLY:
 169		ret = P9_OREAD;
 170		break;
 171
 172	case O_WRONLY:
 173		ret = P9_OWRITE;
 174		break;
 175
 176	case O_RDWR:
 177		ret = P9_ORDWR;
 178		break;
 179	}
 180
 
 
 
 181	if (extended) {
 182		if (uflags & O_EXCL)
 183			ret |= P9_OEXCL;
 184
 185		if (uflags & O_APPEND)
 186			ret |= P9_OAPPEND;
 187	}
 188
 189	return ret;
 190}
 191
 192/**
 193 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 194 * @wstat: structure to initialize
 195 *
 196 */
 197
 198void
 199v9fs_blank_wstat(struct p9_wstat *wstat)
 200{
 201	wstat->type = ~0;
 202	wstat->dev = ~0;
 203	wstat->qid.type = ~0;
 204	wstat->qid.version = ~0;
 205	*((long long *)&wstat->qid.path) = ~0;
 206	wstat->mode = ~0;
 207	wstat->atime = ~0;
 208	wstat->mtime = ~0;
 209	wstat->length = ~0;
 210	wstat->name = NULL;
 211	wstat->uid = NULL;
 212	wstat->gid = NULL;
 213	wstat->muid = NULL;
 214	wstat->n_uid = INVALID_UID;
 215	wstat->n_gid = INVALID_GID;
 216	wstat->n_muid = INVALID_UID;
 217	wstat->extension = NULL;
 218}
 219
 220/**
 221 * v9fs_alloc_inode - helper function to allocate an inode
 222 * @sb: The superblock to allocate the inode from
 223 */
 224struct inode *v9fs_alloc_inode(struct super_block *sb)
 225{
 226	struct v9fs_inode *v9inode;
 227
 228	v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL);
 229	if (!v9inode)
 230		return NULL;
 
 
 
 
 
 231	v9inode->cache_validity = 0;
 232	mutex_init(&v9inode->v_mutex);
 233	return &v9inode->netfs.inode;
 234}
 235
 236/**
 237 * v9fs_free_inode - destroy an inode
 238 * @inode: The inode to be freed
 239 */
 240
 241void v9fs_free_inode(struct inode *inode)
 242{
 
 243	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 244}
 245
 246/*
 247 * Set parameters for the netfs library
 248 */
 249void v9fs_set_netfs_context(struct inode *inode)
 250{
 251	struct v9fs_inode *v9inode = V9FS_I(inode);
 252	netfs_inode_init(&v9inode->netfs, &v9fs_req_ops, true);
 253}
 254
 255int v9fs_init_inode(struct v9fs_session_info *v9ses,
 256		    struct inode *inode, umode_t mode, dev_t rdev)
 257{
 258	int err = 0;
 259
 260	inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
 261	inode->i_blocks = 0;
 262	inode->i_rdev = rdev;
 263	simple_inode_init_ts(inode);
 264	inode->i_mapping->a_ops = &v9fs_addr_operations;
 265	inode->i_private = NULL;
 266
 267	switch (mode & S_IFMT) {
 268	case S_IFIFO:
 269	case S_IFBLK:
 270	case S_IFCHR:
 271	case S_IFSOCK:
 272		if (v9fs_proto_dotl(v9ses)) {
 273			inode->i_op = &v9fs_file_inode_operations_dotl;
 274		} else if (v9fs_proto_dotu(v9ses)) {
 275			inode->i_op = &v9fs_file_inode_operations;
 276		} else {
 277			p9_debug(P9_DEBUG_ERROR,
 278				 "special files without extended mode\n");
 279			err = -EINVAL;
 280			goto error;
 281		}
 282		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 283		break;
 284	case S_IFREG:
 285		if (v9fs_proto_dotl(v9ses)) {
 286			inode->i_op = &v9fs_file_inode_operations_dotl;
 287			inode->i_fop = &v9fs_file_operations_dotl;
 
 
 
 
 288		} else {
 289			inode->i_op = &v9fs_file_inode_operations;
 290			inode->i_fop = &v9fs_file_operations;
 
 
 
 291		}
 292
 293		break;
 294	case S_IFLNK:
 295		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 296			p9_debug(P9_DEBUG_ERROR,
 297				 "extended modes used with legacy protocol\n");
 298			err = -EINVAL;
 299			goto error;
 300		}
 301
 302		if (v9fs_proto_dotl(v9ses))
 303			inode->i_op = &v9fs_symlink_inode_operations_dotl;
 304		else
 305			inode->i_op = &v9fs_symlink_inode_operations;
 306
 307		break;
 308	case S_IFDIR:
 309		inc_nlink(inode);
 310		if (v9fs_proto_dotl(v9ses))
 311			inode->i_op = &v9fs_dir_inode_operations_dotl;
 312		else if (v9fs_proto_dotu(v9ses))
 313			inode->i_op = &v9fs_dir_inode_operations_dotu;
 314		else
 315			inode->i_op = &v9fs_dir_inode_operations;
 316
 317		if (v9fs_proto_dotl(v9ses))
 318			inode->i_fop = &v9fs_dir_operations_dotl;
 319		else
 320			inode->i_fop = &v9fs_dir_operations;
 321
 322		break;
 323	default:
 324		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 325			 mode, mode & S_IFMT);
 326		err = -EINVAL;
 327		goto error;
 328	}
 329error:
 330	return err;
 331
 332}
 333
 334/**
 335 * v9fs_get_inode - helper function to setup an inode
 336 * @sb: superblock
 337 * @mode: mode to setup inode with
 338 * @rdev: The device numbers to set
 339 */
 340
 341struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 342{
 343	int err;
 344	struct inode *inode;
 345	struct v9fs_session_info *v9ses = sb->s_fs_info;
 346
 347	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 348
 349	inode = new_inode(sb);
 350	if (!inode) {
 351		pr_warn("%s (%d): Problem allocating inode\n",
 352			__func__, task_pid_nr(current));
 353		return ERR_PTR(-ENOMEM);
 354	}
 355	err = v9fs_init_inode(v9ses, inode, mode, rdev);
 356	if (err) {
 357		iput(inode);
 358		return ERR_PTR(err);
 359	}
 360	v9fs_set_netfs_context(inode);
 361	return inode;
 362}
 363
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 364/**
 365 * v9fs_evict_inode - Remove an inode from the inode cache
 366 * @inode: inode to release
 367 *
 368 */
 369void v9fs_evict_inode(struct inode *inode)
 370{
 371	struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode);
 372	__le32 __maybe_unused version;
 373
 374	truncate_inode_pages_final(&inode->i_data);
 375
 376	version = cpu_to_le32(v9inode->qid.version);
 377	netfs_clear_inode_writeback(inode, &version);
 378
 
 379	clear_inode(inode);
 380	filemap_fdatawrite(&inode->i_data);
 381
 382#ifdef CONFIG_9P_FSCACHE
 383	fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
 384#endif
 
 
 
 
 
 385}
 386
 387static int v9fs_test_inode(struct inode *inode, void *data)
 388{
 389	int umode;
 390	dev_t rdev;
 391	struct v9fs_inode *v9inode = V9FS_I(inode);
 392	struct p9_wstat *st = (struct p9_wstat *)data;
 393	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 394
 395	umode = p9mode2unixmode(v9ses, st, &rdev);
 396	/* don't match inode of different type */
 397	if (inode_wrong_type(inode, umode))
 398		return 0;
 399
 400	/* compare qid details */
 401	if (memcmp(&v9inode->qid.version,
 402		   &st->qid.version, sizeof(v9inode->qid.version)))
 403		return 0;
 404
 405	if (v9inode->qid.type != st->qid.type)
 406		return 0;
 407
 408	if (v9inode->qid.path != st->qid.path)
 409		return 0;
 410	return 1;
 411}
 412
 413static int v9fs_test_new_inode(struct inode *inode, void *data)
 414{
 415	return 0;
 416}
 417
 418static int v9fs_set_inode(struct inode *inode,  void *data)
 419{
 420	struct v9fs_inode *v9inode = V9FS_I(inode);
 421	struct p9_wstat *st = (struct p9_wstat *)data;
 422
 423	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 424	return 0;
 425}
 426
 427static struct inode *v9fs_qid_iget(struct super_block *sb,
 428				   struct p9_qid *qid,
 429				   struct p9_wstat *st,
 430				   int new)
 431{
 432	dev_t rdev;
 433	int retval;
 434	umode_t umode;
 435	unsigned long i_ino;
 436	struct inode *inode;
 437	struct v9fs_session_info *v9ses = sb->s_fs_info;
 438	int (*test)(struct inode *inode, void *data);
 439
 440	if (new)
 441		test = v9fs_test_new_inode;
 442	else
 443		test = v9fs_test_inode;
 444
 445	i_ino = v9fs_qid2ino(qid);
 446	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 447	if (!inode)
 448		return ERR_PTR(-ENOMEM);
 449	if (!(inode->i_state & I_NEW))
 450		return inode;
 451	/*
 452	 * initialize the inode with the stat info
 453	 * FIXME!! we may need support for stale inodes
 454	 * later.
 455	 */
 456	inode->i_ino = i_ino;
 457	umode = p9mode2unixmode(v9ses, st, &rdev);
 458	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 459	if (retval)
 460		goto error;
 461
 462	v9fs_stat2inode(st, inode, sb, 0);
 463	v9fs_set_netfs_context(inode);
 464	v9fs_cache_inode_get_cookie(inode);
 
 465	unlock_new_inode(inode);
 466	return inode;
 467error:
 468	iget_failed(inode);
 
 469	return ERR_PTR(retval);
 470
 471}
 472
 473struct inode *
 474v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 475		    struct super_block *sb, int new)
 476{
 477	struct p9_wstat *st;
 478	struct inode *inode = NULL;
 479
 480	st = p9_client_stat(fid);
 481	if (IS_ERR(st))
 482		return ERR_CAST(st);
 483
 484	inode = v9fs_qid_iget(sb, &st->qid, st, new);
 485	p9stat_free(st);
 486	kfree(st);
 487	return inode;
 488}
 489
 490/**
 491 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 492 * plan 9 AT flag.
 493 * @flags: flags to convert
 494 */
 495static int v9fs_at_to_dotl_flags(int flags)
 496{
 497	int rflags = 0;
 498
 499	if (flags & AT_REMOVEDIR)
 500		rflags |= P9_DOTL_AT_REMOVEDIR;
 501
 502	return rflags;
 503}
 504
 505/**
 506 * v9fs_dec_count - helper functon to drop i_nlink.
 507 *
 508 * If a directory had nlink <= 2 (including . and ..), then we should not drop
 509 * the link count, which indicates the underlying exported fs doesn't maintain
 510 * nlink accurately. e.g.
 511 * - overlayfs sets nlink to 1 for merged dir
 512 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
 513 *   than EXT4_LINK_MAX (65000) links.
 514 *
 515 * @inode: inode whose nlink is being dropped
 516 */
 517static void v9fs_dec_count(struct inode *inode)
 518{
 519	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
 520		drop_nlink(inode);
 521}
 522
 523/**
 524 * v9fs_remove - helper function to remove files and directories
 525 * @dir: directory inode that is being deleted
 526 * @dentry:  dentry that is being deleted
 527 * @flags: removing a directory
 528 *
 529 */
 530
 531static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 532{
 533	struct inode *inode;
 534	int retval = -EOPNOTSUPP;
 535	struct p9_fid *v9fid, *dfid;
 536	struct v9fs_session_info *v9ses;
 537
 538	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 539		 dir, dentry, flags);
 540
 541	v9ses = v9fs_inode2v9ses(dir);
 542	inode = d_inode(dentry);
 543	dfid = v9fs_parent_fid(dentry);
 544	if (IS_ERR(dfid)) {
 545		retval = PTR_ERR(dfid);
 546		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 547		return retval;
 548	}
 549	if (v9fs_proto_dotl(v9ses))
 550		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 551					    v9fs_at_to_dotl_flags(flags));
 552	p9_fid_put(dfid);
 553	if (retval == -EOPNOTSUPP) {
 554		/* Try the one based on path */
 555		v9fid = v9fs_fid_clone(dentry);
 556		if (IS_ERR(v9fid))
 557			return PTR_ERR(v9fid);
 558		retval = p9_client_remove(v9fid);
 559	}
 560	if (!retval) {
 561		/*
 562		 * directories on unlink should have zero
 563		 * link count
 564		 */
 565		if (flags & AT_REMOVEDIR) {
 566			clear_nlink(inode);
 567			v9fs_dec_count(dir);
 568		} else
 569			v9fs_dec_count(inode);
 570
 571		v9fs_invalidate_inode_attr(inode);
 572		v9fs_invalidate_inode_attr(dir);
 573
 574		/* invalidate all fids associated with dentry */
 575		/* NOTE: This will not include open fids */
 576		dentry->d_op->d_release(dentry);
 577	}
 578	return retval;
 579}
 580
 581/**
 582 * v9fs_create - Create a file
 583 * @v9ses: session information
 584 * @dir: directory that dentry is being created in
 585 * @dentry:  dentry that is being created
 586 * @extension: 9p2000.u extension string to support devices, etc.
 587 * @perm: create permissions
 588 * @mode: open mode
 589 *
 590 */
 591static struct p9_fid *
 592v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 593		struct dentry *dentry, char *extension, u32 perm, u8 mode)
 594{
 595	int err;
 596	const unsigned char *name;
 597	struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
 598	struct inode *inode;
 599
 600	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 601
 602	name = dentry->d_name.name;
 603	dfid = v9fs_parent_fid(dentry);
 
 
 
 604	if (IS_ERR(dfid)) {
 605		err = PTR_ERR(dfid);
 606		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 607		return ERR_PTR(err);
 608	}
 609
 610	/* clone a fid to use for creation */
 611	ofid = clone_fid(dfid);
 612	if (IS_ERR(ofid)) {
 613		err = PTR_ERR(ofid);
 614		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 615		goto error;
 616	}
 617
 618	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 619	if (err < 0) {
 620		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 621		goto error;
 622	}
 623
 624	if (!(perm & P9_DMLINK)) {
 625		/* now walk from the parent so we can get unopened fid */
 626		fid = p9_client_walk(dfid, 1, &name, 1);
 627		if (IS_ERR(fid)) {
 628			err = PTR_ERR(fid);
 629			p9_debug(P9_DEBUG_VFS,
 630				   "p9_client_walk failed %d\n", err);
 
 631			goto error;
 632		}
 633		/*
 634		 * instantiate inode and assign the unopened fid to the dentry
 635		 */
 636		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 637		if (IS_ERR(inode)) {
 638			err = PTR_ERR(inode);
 639			p9_debug(P9_DEBUG_VFS,
 640				   "inode creation failed %d\n", err);
 641			goto error;
 642		}
 643		v9fs_fid_add(dentry, &fid);
 
 
 644		d_instantiate(dentry, inode);
 645	}
 646	p9_fid_put(dfid);
 647	return ofid;
 648error:
 649	p9_fid_put(dfid);
 650	p9_fid_put(ofid);
 651	p9_fid_put(fid);
 
 
 
 652	return ERR_PTR(err);
 653}
 654
 655/**
 656 * v9fs_vfs_create - VFS hook to create a regular file
 657 * @idmap: idmap of the mount
 658 * @dir: The parent directory
 659 * @dentry: The name of file to be created
 660 * @mode: The UNIX file mode to set
 661 * @excl: True if the file must not yet exist
 662 *
 663 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 664 * for mknod(2).
 665 *
 666 */
 667
 668static int
 669v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
 670		struct dentry *dentry, umode_t mode, bool excl)
 671{
 672	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 673	u32 perm = unixmode2p9mode(v9ses, mode);
 674	struct p9_fid *fid;
 
 
 
 
 
 
 
 
 
 
 
 
 
 675
 676	/* P9_OEXCL? */
 677	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 678	if (IS_ERR(fid))
 679		return PTR_ERR(fid);
 
 
 
 
 680
 681	v9fs_invalidate_inode_attr(dir);
 682	p9_fid_put(fid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 683
 684	return 0;
 
 
 
 
 
 
 685}
 686
 687/**
 688 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 689 * @idmap: idmap of the mount
 690 * @dir:  inode that is being unlinked
 691 * @dentry: dentry that is being unlinked
 692 * @mode: mode for new directory
 693 *
 694 */
 695
 696static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 697			  struct dentry *dentry, umode_t mode)
 698{
 699	int err;
 700	u32 perm;
 701	struct p9_fid *fid;
 702	struct v9fs_session_info *v9ses;
 703
 704	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 705	err = 0;
 706	v9ses = v9fs_inode2v9ses(dir);
 707	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 708	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 709	if (IS_ERR(fid)) {
 710		err = PTR_ERR(fid);
 711		fid = NULL;
 712	} else {
 713		inc_nlink(dir);
 714		v9fs_invalidate_inode_attr(dir);
 715	}
 716
 717	if (fid)
 718		p9_fid_put(fid);
 719
 720	return err;
 721}
 722
 723/**
 724 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 725 * @dir:  inode that is being walked from
 726 * @dentry: dentry that is being walked to?
 727 * @flags: lookup flags (unused)
 728 *
 729 */
 730
 731struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 732				      unsigned int flags)
 733{
 734	struct dentry *res;
 
 735	struct v9fs_session_info *v9ses;
 736	struct p9_fid *dfid, *fid;
 737	struct inode *inode;
 738	const unsigned char *name;
 
 739
 740	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
 741		 dir, dentry, dentry, flags);
 742
 743	if (dentry->d_name.len > NAME_MAX)
 744		return ERR_PTR(-ENAMETOOLONG);
 745
 
 746	v9ses = v9fs_inode2v9ses(dir);
 747	/* We can walk d_parent because we hold the dir->i_mutex */
 748	dfid = v9fs_parent_fid(dentry);
 749	if (IS_ERR(dfid))
 750		return ERR_CAST(dfid);
 751
 
 
 
 
 
 
 
 
 
 
 
 752	/*
 753	 * Make sure we don't use a wrong inode due to parallel
 754	 * unlink. For cached mode create calls request for new
 755	 * inode. But with cache disabled, lookup should do this.
 756	 */
 757	name = dentry->d_name.name;
 758	fid = p9_client_walk(dfid, 1, &name, 1);
 759	p9_fid_put(dfid);
 760	if (fid == ERR_PTR(-ENOENT))
 761		inode = NULL;
 762	else if (IS_ERR(fid))
 763		inode = ERR_CAST(fid);
 764	else if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
 765		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 766	else
 767		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 
 
 
 
 
 
 
 
 
 768	/*
 769	 * If we had a rename on the server and a parallel lookup
 770	 * for the new name, then make sure we instantiate with
 771	 * the new name. ie look up for a/b, while on server somebody
 772	 * moved b under k and client parallely did a lookup for
 773	 * k/b.
 774	 */
 775	res = d_splice_alias(inode, dentry);
 776	if (!IS_ERR(fid)) {
 777		if (!res)
 778			v9fs_fid_add(dentry, &fid);
 779		else if (!IS_ERR(res))
 780			v9fs_fid_add(res, &fid);
 781		else
 782			p9_fid_put(fid);
 783	}
 784	return res;
 785}
 786
 787static int
 788v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 789		     struct file *file, unsigned int flags, umode_t mode)
 790{
 791	int err;
 792	u32 perm;
 793	struct v9fs_inode __maybe_unused *v9inode;
 794	struct v9fs_session_info *v9ses;
 795	struct p9_fid *fid;
 796	struct dentry *res = NULL;
 797	struct inode *inode;
 798	int p9_omode;
 799
 800	if (d_in_lookup(dentry)) {
 801		res = v9fs_vfs_lookup(dir, dentry, 0);
 802		if (IS_ERR(res))
 803			return PTR_ERR(res);
 804
 805		if (res)
 806			dentry = res;
 807	}
 808
 809	/* Only creates */
 810	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
 811		return finish_no_open(file, res);
 812
 813	v9ses = v9fs_inode2v9ses(dir);
 814	perm = unixmode2p9mode(v9ses, mode);
 815	p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
 816
 817	if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
 818		p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
 819		p9_debug(P9_DEBUG_CACHE,
 820			"write-only file with writeback enabled, creating w/ O_RDWR\n");
 821	}
 822	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode);
 823	if (IS_ERR(fid)) {
 824		err = PTR_ERR(fid);
 825		goto error;
 826	}
 827
 828	v9fs_invalidate_inode_attr(dir);
 829	inode = d_inode(dentry);
 830	v9inode = V9FS_I(inode);
 831	err = finish_open(file, dentry, generic_file_open);
 832	if (err)
 833		goto error;
 834
 835	file->private_data = fid;
 836#ifdef CONFIG_9P_FSCACHE
 837	if (v9ses->cache & CACHE_FSCACHE)
 838		fscache_use_cookie(v9fs_inode_cookie(v9inode),
 839				   file->f_mode & FMODE_WRITE);
 840#endif
 841
 842	v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
 843	v9fs_open_fid_add(inode, &fid);
 844
 845	file->f_mode |= FMODE_CREATED;
 846out:
 847	dput(res);
 848	return err;
 849
 850error:
 851	p9_fid_put(fid);
 852	goto out;
 853}
 854
 855/**
 856 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 857 * @i:  inode that is being unlinked
 858 * @d: dentry that is being unlinked
 859 *
 860 */
 861
 862int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 863{
 864	return v9fs_remove(i, d, 0);
 865}
 866
 867/**
 868 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 869 * @i:  inode that is being unlinked
 870 * @d: dentry that is being unlinked
 871 *
 872 */
 873
 874int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 875{
 876	return v9fs_remove(i, d, AT_REMOVEDIR);
 877}
 878
 879/**
 880 * v9fs_vfs_rename - VFS hook to rename an inode
 881 * @idmap: The idmap of the mount
 882 * @old_dir:  old dir inode
 883 * @old_dentry: old dentry
 884 * @new_dir: new dir inode
 885 * @new_dentry: new dentry
 886 * @flags: RENAME_* flags
 887 *
 888 */
 889
 890int
 891v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 892		struct dentry *old_dentry, struct inode *new_dir,
 893		struct dentry *new_dentry, unsigned int flags)
 894{
 895	int retval;
 896	struct inode *old_inode;
 897	struct inode *new_inode;
 898	struct v9fs_session_info *v9ses;
 899	struct p9_fid *oldfid = NULL, *dfid = NULL;
 900	struct p9_fid *olddirfid = NULL;
 901	struct p9_fid *newdirfid = NULL;
 902	struct p9_wstat wstat;
 903
 904	if (flags)
 905		return -EINVAL;
 906
 907	p9_debug(P9_DEBUG_VFS, "\n");
 908	old_inode = d_inode(old_dentry);
 909	new_inode = d_inode(new_dentry);
 
 910	v9ses = v9fs_inode2v9ses(old_inode);
 911	oldfid = v9fs_fid_lookup(old_dentry);
 912	if (IS_ERR(oldfid))
 913		return PTR_ERR(oldfid);
 914
 915	dfid = v9fs_parent_fid(old_dentry);
 916	olddirfid = clone_fid(dfid);
 917	p9_fid_put(dfid);
 918	dfid = NULL;
 919
 920	if (IS_ERR(olddirfid)) {
 921		retval = PTR_ERR(olddirfid);
 922		goto error;
 923	}
 924
 925	dfid = v9fs_parent_fid(new_dentry);
 926	newdirfid = clone_fid(dfid);
 927	p9_fid_put(dfid);
 928	dfid = NULL;
 929
 930	if (IS_ERR(newdirfid)) {
 931		retval = PTR_ERR(newdirfid);
 932		goto error;
 933	}
 934
 935	down_write(&v9ses->rename_sem);
 936	if (v9fs_proto_dotl(v9ses)) {
 937		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 938					    newdirfid, new_dentry->d_name.name);
 939		if (retval == -EOPNOTSUPP)
 940			retval = p9_client_rename(oldfid, newdirfid,
 941						  new_dentry->d_name.name);
 942		if (retval != -EOPNOTSUPP)
 943			goto error_locked;
 944	}
 945	if (old_dentry->d_parent != new_dentry->d_parent) {
 946		/*
 947		 * 9P .u can only handle file rename in the same directory
 948		 */
 949
 950		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 951		retval = -EXDEV;
 952		goto error_locked;
 953	}
 954	v9fs_blank_wstat(&wstat);
 955	wstat.muid = v9ses->uname;
 956	wstat.name = new_dentry->d_name.name;
 957	retval = p9_client_wstat(oldfid, &wstat);
 958
 959error_locked:
 960	if (!retval) {
 961		if (new_inode) {
 962			if (S_ISDIR(new_inode->i_mode))
 963				clear_nlink(new_inode);
 964			else
 965				v9fs_dec_count(new_inode);
 966		}
 967		if (S_ISDIR(old_inode->i_mode)) {
 968			if (!new_inode)
 969				inc_nlink(new_dir);
 970			v9fs_dec_count(old_dir);
 971		}
 972		v9fs_invalidate_inode_attr(old_inode);
 973		v9fs_invalidate_inode_attr(old_dir);
 974		v9fs_invalidate_inode_attr(new_dir);
 975
 976		/* successful rename */
 977		d_move(old_dentry, new_dentry);
 978	}
 979	up_write(&v9ses->rename_sem);
 
 
 
 
 980
 981error:
 982	p9_fid_put(newdirfid);
 983	p9_fid_put(olddirfid);
 984	p9_fid_put(oldfid);
 985	return retval;
 986}
 987
 988/**
 989 * v9fs_vfs_getattr - retrieve file metadata
 990 * @idmap: idmap of the mount
 991 * @path: Object to query
 992 * @stat: metadata structure to populate
 993 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
 994 * @flags: AT_STATX_xxx setting
 995 *
 996 */
 997
 998static int
 999v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path,
1000		 struct kstat *stat, u32 request_mask, unsigned int flags)
1001{
1002	struct dentry *dentry = path->dentry;
1003	struct inode *inode = d_inode(dentry);
1004	struct v9fs_session_info *v9ses;
1005	struct p9_fid *fid;
1006	struct p9_wstat *st;
1007
1008	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 
1009	v9ses = v9fs_dentry2v9ses(dentry);
1010	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
1011		generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1012		return 0;
1013	} else if (v9ses->cache & CACHE_WRITEBACK) {
1014		if (S_ISREG(inode->i_mode)) {
1015			int retval = filemap_fdatawrite(inode->i_mapping);
1016
1017			if (retval)
1018				p9_debug(P9_DEBUG_ERROR,
1019				    "flushing writeback during getattr returned %d\n", retval);
1020		}
1021	}
1022	fid = v9fs_fid_lookup(dentry);
1023	if (IS_ERR(fid))
1024		return PTR_ERR(fid);
1025
1026	st = p9_client_stat(fid);
1027	p9_fid_put(fid);
1028	if (IS_ERR(st))
1029		return PTR_ERR(st);
1030
1031	v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1032	generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
1033
1034	p9stat_free(st);
1035	kfree(st);
1036	return 0;
1037}
1038
1039/**
1040 * v9fs_vfs_setattr - set file metadata
1041 * @idmap: idmap of the mount
1042 * @dentry: file whose metadata to set
1043 * @iattr: metadata assignment structure
1044 *
1045 */
1046
1047static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
1048			    struct dentry *dentry, struct iattr *iattr)
1049{
1050	int retval, use_dentry = 0;
1051	struct inode *inode = d_inode(dentry);
1052	struct v9fs_session_info *v9ses;
1053	struct p9_fid *fid = NULL;
1054	struct p9_wstat wstat;
1055
1056	p9_debug(P9_DEBUG_VFS, "\n");
1057	retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
1058	if (retval)
1059		return retval;
1060
 
1061	v9ses = v9fs_dentry2v9ses(dentry);
1062	if (iattr->ia_valid & ATTR_FILE) {
1063		fid = iattr->ia_file->private_data;
1064		WARN_ON(!fid);
1065	}
1066	if (!fid) {
1067		fid = v9fs_fid_lookup(dentry);
1068		use_dentry = 1;
1069	}
1070	if (IS_ERR(fid))
1071		return PTR_ERR(fid);
1072
1073	v9fs_blank_wstat(&wstat);
1074	if (iattr->ia_valid & ATTR_MODE)
1075		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1076
1077	if (iattr->ia_valid & ATTR_MTIME)
1078		wstat.mtime = iattr->ia_mtime.tv_sec;
1079
1080	if (iattr->ia_valid & ATTR_ATIME)
1081		wstat.atime = iattr->ia_atime.tv_sec;
1082
1083	if (iattr->ia_valid & ATTR_SIZE)
1084		wstat.length = iattr->ia_size;
1085
1086	if (v9fs_proto_dotu(v9ses)) {
1087		if (iattr->ia_valid & ATTR_UID)
1088			wstat.n_uid = iattr->ia_uid;
1089
1090		if (iattr->ia_valid & ATTR_GID)
1091			wstat.n_gid = iattr->ia_gid;
1092	}
1093
1094	/* Write all dirty data */
1095	if (d_is_reg(dentry)) {
1096		retval = filemap_fdatawrite(inode->i_mapping);
1097		if (retval)
1098			p9_debug(P9_DEBUG_ERROR,
1099			    "flushing writeback during setattr returned %d\n", retval);
1100	}
1101
1102	retval = p9_client_wstat(fid, &wstat);
1103
1104	if (use_dentry)
1105		p9_fid_put(fid);
1106
1107	if (retval < 0)
1108		return retval;
1109
1110	if ((iattr->ia_valid & ATTR_SIZE) &&
1111		 iattr->ia_size != i_size_read(inode)) {
1112		truncate_setsize(inode, iattr->ia_size);
1113		netfs_resize_file(netfs_inode(inode), iattr->ia_size, true);
1114
1115#ifdef CONFIG_9P_FSCACHE
1116		if (v9ses->cache & CACHE_FSCACHE) {
1117			struct v9fs_inode *v9inode = V9FS_I(inode);
1118
1119			fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1120		}
1121#endif
1122	}
1123
1124	v9fs_invalidate_inode_attr(inode);
1125
1126	setattr_copy(&nop_mnt_idmap, inode, iattr);
1127	mark_inode_dirty(inode);
1128	return 0;
1129}
1130
1131/**
1132 * v9fs_stat2inode - populate an inode structure with mistat info
1133 * @stat: Plan 9 metadata (mistat) structure
1134 * @inode: inode to populate
1135 * @sb: superblock of filesystem
1136 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1137 *
1138 */
1139
1140void
1141v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1142		 struct super_block *sb, unsigned int flags)
1143{
1144	umode_t mode;
 
 
 
1145	struct v9fs_session_info *v9ses = sb->s_fs_info;
1146	struct v9fs_inode *v9inode = V9FS_I(inode);
1147
1148	set_nlink(inode, 1);
1149
1150	inode_set_atime(inode, stat->atime, 0);
1151	inode_set_mtime(inode, stat->mtime, 0);
1152	inode_set_ctime(inode, stat->mtime, 0);
1153
1154	inode->i_uid = v9ses->dfltuid;
1155	inode->i_gid = v9ses->dfltgid;
1156
1157	if (v9fs_proto_dotu(v9ses)) {
1158		inode->i_uid = stat->n_uid;
1159		inode->i_gid = stat->n_gid;
1160	}
1161	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1162		if (v9fs_proto_dotu(v9ses)) {
1163			unsigned int i_nlink;
1164			/*
1165			 * Hadlink support got added later to the .u extension.
1166			 * So there can be a server out there that doesn't
1167			 * support this even with .u extension. That would
1168			 * just leave us with stat->extension being an empty
1169			 * string, though.
1170			 */
 
1171			/* HARDLINKCOUNT %u */
1172			if (sscanf(stat->extension,
1173				   " HARDLINKCOUNT %u", &i_nlink) == 1)
1174				set_nlink(inode, i_nlink);
1175		}
1176	}
1177	mode = p9mode2perm(v9ses, stat);
1178	mode |= inode->i_mode & ~S_IALLUGO;
1179	inode->i_mode = mode;
 
1180
1181	v9inode->netfs.remote_i_size = stat->length;
1182	if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1183		v9fs_i_size_write(inode, stat->length);
1184	/* not real number of blocks, but 512 byte ones ... */
1185	inode->i_blocks = (stat->length + 512 - 1) >> 9;
1186	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1187}
1188
1189/**
1190 * v9fs_qid2ino - convert qid into inode number
1191 * @qid: qid to hash
1192 *
1193 * BUG: potential for inode number collisions?
1194 */
1195
1196ino_t v9fs_qid2ino(struct p9_qid *qid)
1197{
1198	u64 path = qid->path + 2;
1199	ino_t i = 0;
1200
1201	if (sizeof(ino_t) == sizeof(path))
1202		memcpy(&i, &path, sizeof(ino_t));
1203	else
1204		i = (ino_t) (path ^ (path >> 32));
1205
1206	return i;
1207}
1208
1209/**
1210 * v9fs_vfs_get_link - follow a symlink path
1211 * @dentry: dentry for symlink
1212 * @inode: inode for symlink
1213 * @done: delayed call for when we are done with the return value
 
1214 */
1215
1216static const char *v9fs_vfs_get_link(struct dentry *dentry,
1217				     struct inode *inode,
1218				     struct delayed_call *done)
1219{
 
 
1220	struct v9fs_session_info *v9ses;
1221	struct p9_fid *fid;
1222	struct p9_wstat *st;
1223	char *res;
1224
1225	if (!dentry)
1226		return ERR_PTR(-ECHILD);
1227
 
 
1228	v9ses = v9fs_dentry2v9ses(dentry);
1229	if (!v9fs_proto_dotu(v9ses))
1230		return ERR_PTR(-EBADF);
1231
1232	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1233	fid = v9fs_fid_lookup(dentry);
 
 
1234
1235	if (IS_ERR(fid))
1236		return ERR_CAST(fid);
1237
1238	st = p9_client_stat(fid);
1239	p9_fid_put(fid);
1240	if (IS_ERR(st))
1241		return ERR_CAST(st);
1242
1243	if (!(st->mode & P9_DMSYMLINK)) {
1244		p9stat_free(st);
1245		kfree(st);
1246		return ERR_PTR(-EINVAL);
1247	}
1248	res = st->extension;
1249	st->extension = NULL;
1250	if (strlen(res) >= PATH_MAX)
1251		res[PATH_MAX - 1] = '\0';
 
1252
 
 
1253	p9stat_free(st);
1254	kfree(st);
1255	set_delayed_call(done, kfree_link, res);
1256	return res;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1257}
1258
1259/**
1260 * v9fs_vfs_mkspecial - create a special file
1261 * @dir: inode to create special file in
1262 * @dentry: dentry to create
1263 * @perm: mode to create special file
1264 * @extension: 9p2000.u format extension string representing special file
1265 *
1266 */
1267
1268static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1269	u32 perm, const char *extension)
1270{
1271	struct p9_fid *fid;
1272	struct v9fs_session_info *v9ses;
1273
1274	v9ses = v9fs_inode2v9ses(dir);
1275	if (!v9fs_proto_dotu(v9ses)) {
1276		p9_debug(P9_DEBUG_ERROR, "not extended\n");
1277		return -EPERM;
1278	}
1279
1280	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1281								P9_OREAD);
1282	if (IS_ERR(fid))
1283		return PTR_ERR(fid);
1284
1285	v9fs_invalidate_inode_attr(dir);
1286	p9_fid_put(fid);
1287	return 0;
1288}
1289
1290/**
1291 * v9fs_vfs_symlink - helper function to create symlinks
1292 * @idmap: idmap of the mount
1293 * @dir: directory inode containing symlink
1294 * @dentry: dentry for symlink
1295 * @symname: symlink data
1296 *
1297 * See Also: 9P2000.u RFC for more information
1298 *
1299 */
1300
1301static int
1302v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1303		 struct dentry *dentry, const char *symname)
1304{
1305	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1306		 dir->i_ino, dentry, symname);
1307
1308	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1309}
1310
1311#define U32_MAX_DIGITS 10
1312
1313/**
1314 * v9fs_vfs_link - create a hardlink
1315 * @old_dentry: dentry for file to link to
1316 * @dir: inode destination for new link
1317 * @dentry: dentry for link
1318 *
1319 */
1320
1321static int
1322v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1323	      struct dentry *dentry)
1324{
1325	int retval;
1326	char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1327	struct p9_fid *oldfid;
1328
1329	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1330		 dir->i_ino, dentry, old_dentry);
1331
1332	oldfid = v9fs_fid_clone(old_dentry);
1333	if (IS_ERR(oldfid))
1334		return PTR_ERR(oldfid);
1335
 
 
 
 
 
 
1336	sprintf(name, "%d\n", oldfid->fid);
1337	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
 
1338	if (!retval) {
1339		v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1340		v9fs_invalidate_inode_attr(dir);
1341	}
1342	p9_fid_put(oldfid);
 
1343	return retval;
1344}
1345
1346/**
1347 * v9fs_vfs_mknod - create a special file
1348 * @idmap: idmap of the mount
1349 * @dir: inode destination for new link
1350 * @dentry: dentry for file
1351 * @mode: mode for creation
1352 * @rdev: device associated with special file
1353 *
1354 */
1355
1356static int
1357v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1358	       struct dentry *dentry, umode_t mode, dev_t rdev)
1359{
1360	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1361	int retval;
1362	char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1363	u32 perm;
1364
1365	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1366		 dir->i_ino, dentry, mode,
1367		 MAJOR(rdev), MINOR(rdev));
1368
 
 
 
 
 
 
1369	/* build extension */
1370	if (S_ISBLK(mode))
1371		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1372	else if (S_ISCHR(mode))
1373		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1374	else
 
 
1375		*name = 0;
 
 
 
 
1376
1377	perm = unixmode2p9mode(v9ses, mode);
1378	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
 
1379
1380	return retval;
1381}
1382
1383int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1384{
1385	int umode;
1386	dev_t rdev;
 
1387	struct p9_wstat *st;
1388	struct v9fs_session_info *v9ses;
1389	unsigned int flags;
1390
1391	v9ses = v9fs_inode2v9ses(inode);
1392	st = p9_client_stat(fid);
1393	if (IS_ERR(st))
1394		return PTR_ERR(st);
1395	/*
1396	 * Don't update inode if the file type is different
1397	 */
1398	umode = p9mode2unixmode(v9ses, st, &rdev);
1399	if (inode_wrong_type(inode, umode))
1400		goto out;
1401
 
1402	/*
1403	 * We don't want to refresh inode->i_size,
1404	 * because we may have cached data
1405	 */
1406	flags = (v9ses->cache & CACHE_LOOSE) ?
1407		V9FS_STAT2INODE_KEEP_ISIZE : 0;
1408	v9fs_stat2inode(st, inode, inode->i_sb, flags);
 
 
1409out:
1410	p9stat_free(st);
1411	kfree(st);
1412	return 0;
1413}
1414
1415static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1416	.create = v9fs_vfs_create,
1417	.lookup = v9fs_vfs_lookup,
1418	.atomic_open = v9fs_vfs_atomic_open,
1419	.symlink = v9fs_vfs_symlink,
1420	.link = v9fs_vfs_link,
1421	.unlink = v9fs_vfs_unlink,
1422	.mkdir = v9fs_vfs_mkdir,
1423	.rmdir = v9fs_vfs_rmdir,
1424	.mknod = v9fs_vfs_mknod,
1425	.rename = v9fs_vfs_rename,
1426	.getattr = v9fs_vfs_getattr,
1427	.setattr = v9fs_vfs_setattr,
1428};
1429
1430static const struct inode_operations v9fs_dir_inode_operations = {
1431	.create = v9fs_vfs_create,
1432	.lookup = v9fs_vfs_lookup,
1433	.atomic_open = v9fs_vfs_atomic_open,
1434	.unlink = v9fs_vfs_unlink,
1435	.mkdir = v9fs_vfs_mkdir,
1436	.rmdir = v9fs_vfs_rmdir,
1437	.mknod = v9fs_vfs_mknod,
1438	.rename = v9fs_vfs_rename,
1439	.getattr = v9fs_vfs_getattr,
1440	.setattr = v9fs_vfs_setattr,
1441};
1442
1443static const struct inode_operations v9fs_file_inode_operations = {
1444	.getattr = v9fs_vfs_getattr,
1445	.setattr = v9fs_vfs_setattr,
1446};
1447
1448static const struct inode_operations v9fs_symlink_inode_operations = {
1449	.get_link = v9fs_vfs_get_link,
 
 
1450	.getattr = v9fs_vfs_getattr,
1451	.setattr = v9fs_vfs_setattr,
1452};
1453