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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
v6.2
   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/inet.h>
  19#include <linux/namei.h>
 
  20#include <linux/sched.h>
  21#include <linux/slab.h>
  22#include <linux/xattr.h>
  23#include <linux/posix_acl.h>
  24#include <net/9p/9p.h>
  25#include <net/9p/client.h>
  26
  27#include "v9fs.h"
  28#include "v9fs_vfs.h"
  29#include "fid.h"
  30#include "cache.h"
  31#include "xattr.h"
  32#include "acl.h"
  33
  34static const struct inode_operations v9fs_dir_inode_operations;
  35static const struct inode_operations v9fs_dir_inode_operations_dotu;
  36static const struct inode_operations v9fs_file_inode_operations;
  37static const struct inode_operations v9fs_symlink_inode_operations;
  38
  39/**
  40 * unixmode2p9mode - convert unix mode bits to plan 9
  41 * @v9ses: v9fs session information
  42 * @mode: mode to convert
  43 *
  44 */
  45
  46static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
  47{
  48	int res;
  49
  50	res = mode & 0777;
  51	if (S_ISDIR(mode))
  52		res |= P9_DMDIR;
  53	if (v9fs_proto_dotu(v9ses)) {
  54		if (v9ses->nodev == 0) {
  55			if (S_ISSOCK(mode))
  56				res |= P9_DMSOCKET;
  57			if (S_ISFIFO(mode))
  58				res |= P9_DMNAMEDPIPE;
  59			if (S_ISBLK(mode))
  60				res |= P9_DMDEVICE;
  61			if (S_ISCHR(mode))
  62				res |= P9_DMDEVICE;
  63		}
  64
  65		if ((mode & S_ISUID) == S_ISUID)
  66			res |= P9_DMSETUID;
  67		if ((mode & S_ISGID) == S_ISGID)
  68			res |= P9_DMSETGID;
  69		if ((mode & S_ISVTX) == S_ISVTX)
  70			res |= P9_DMSETVTX;
  71	}
  72	return res;
  73}
  74
  75/**
  76 * p9mode2perm- convert plan9 mode bits to unix permission bits
  77 * @v9ses: v9fs session information
  78 * @stat: p9_wstat from which mode need to be derived
  79 *
  80 */
  81static int p9mode2perm(struct v9fs_session_info *v9ses,
  82		       struct p9_wstat *stat)
  83{
  84	int res;
  85	int mode = stat->mode;
  86
  87	res = mode & S_IALLUGO;
  88	if (v9fs_proto_dotu(v9ses)) {
  89		if ((mode & P9_DMSETUID) == P9_DMSETUID)
  90			res |= S_ISUID;
  91
  92		if ((mode & P9_DMSETGID) == P9_DMSETGID)
  93			res |= S_ISGID;
  94
  95		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
  96			res |= S_ISVTX;
  97	}
  98	return res;
  99}
 100
 101/**
 102 * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 103 * @v9ses: v9fs session information
 104 * @stat: p9_wstat from which mode need to be derived
 105 * @rdev: major number, minor number in case of device files.
 106 *
 107 */
 108static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 109			       struct p9_wstat *stat, dev_t *rdev)
 110{
 111	int res, r;
 112	u32 mode = stat->mode;
 113
 114	*rdev = 0;
 115	res = p9mode2perm(v9ses, stat);
 116
 117	if ((mode & P9_DMDIR) == P9_DMDIR)
 118		res |= S_IFDIR;
 119	else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 120		res |= S_IFLNK;
 121	else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 122		 && (v9ses->nodev == 0))
 123		res |= S_IFSOCK;
 124	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 125		 && (v9ses->nodev == 0))
 126		res |= S_IFIFO;
 127	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 128		 && (v9ses->nodev == 0)) {
 129		char type = 0;
 130		int major = -1, minor = -1;
 131
 132		r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
 133		if (r != 3) {
 134			p9_debug(P9_DEBUG_ERROR,
 135				 "invalid device string, umode will be bogus: %s\n",
 136				 stat->extension);
 137			return res;
 138		}
 139		switch (type) {
 140		case 'c':
 141			res |= S_IFCHR;
 142			break;
 143		case 'b':
 144			res |= S_IFBLK;
 145			break;
 146		default:
 147			p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 148				 type, stat->extension);
 149		}
 150		*rdev = MKDEV(major, minor);
 151	} else
 152		res |= S_IFREG;
 153
 154	return res;
 155}
 156
 157/**
 158 * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 159 * @uflags: flags to convert
 160 * @extended: if .u extensions are active
 161 */
 162
 163int v9fs_uflags2omode(int uflags, int extended)
 164{
 165	int ret;
 166
 167	ret = 0;
 168	switch (uflags&3) {
 169	default:
 170	case O_RDONLY:
 171		ret = P9_OREAD;
 172		break;
 173
 174	case O_WRONLY:
 175		ret = P9_OWRITE;
 176		break;
 177
 178	case O_RDWR:
 179		ret = P9_ORDWR;
 180		break;
 181	}
 182
 
 
 
 183	if (extended) {
 184		if (uflags & O_EXCL)
 185			ret |= P9_OEXCL;
 186
 187		if (uflags & O_APPEND)
 188			ret |= P9_OAPPEND;
 189	}
 190
 191	return ret;
 192}
 193
 194/**
 195 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 196 * @wstat: structure to initialize
 197 *
 198 */
 199
 200void
 201v9fs_blank_wstat(struct p9_wstat *wstat)
 202{
 203	wstat->type = ~0;
 204	wstat->dev = ~0;
 205	wstat->qid.type = ~0;
 206	wstat->qid.version = ~0;
 207	*((long long *)&wstat->qid.path) = ~0;
 208	wstat->mode = ~0;
 209	wstat->atime = ~0;
 210	wstat->mtime = ~0;
 211	wstat->length = ~0;
 212	wstat->name = NULL;
 213	wstat->uid = NULL;
 214	wstat->gid = NULL;
 215	wstat->muid = NULL;
 216	wstat->n_uid = INVALID_UID;
 217	wstat->n_gid = INVALID_GID;
 218	wstat->n_muid = INVALID_UID;
 219	wstat->extension = NULL;
 220}
 221
 222/**
 223 * v9fs_alloc_inode - helper function to allocate an inode
 224 * @sb: The superblock to allocate the inode from
 225 */
 226struct inode *v9fs_alloc_inode(struct super_block *sb)
 227{
 228	struct v9fs_inode *v9inode;
 229
 230	v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL);
 231	if (!v9inode)
 232		return NULL;
 
 
 
 
 233	v9inode->writeback_fid = NULL;
 234	v9inode->cache_validity = 0;
 235	mutex_init(&v9inode->v_mutex);
 236	return &v9inode->netfs.inode;
 237}
 238
 239/**
 240 * v9fs_free_inode - destroy an inode
 241 * @inode: The inode to be freed
 242 */
 243
 244void v9fs_free_inode(struct inode *inode)
 245{
 
 246	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 247}
 248
 249/*
 250 * Set parameters for the netfs library
 251 */
 252static void v9fs_set_netfs_context(struct inode *inode)
 253{
 254	struct v9fs_inode *v9inode = V9FS_I(inode);
 255	netfs_inode_init(&v9inode->netfs, &v9fs_req_ops);
 256}
 257
 258int v9fs_init_inode(struct v9fs_session_info *v9ses,
 259		    struct inode *inode, umode_t mode, dev_t rdev)
 260{
 261	int err = 0;
 262
 263	inode_init_owner(&init_user_ns, inode, NULL, mode);
 264	inode->i_blocks = 0;
 265	inode->i_rdev = rdev;
 266	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 267	inode->i_mapping->a_ops = &v9fs_addr_operations;
 268	inode->i_private = NULL;
 269
 270	switch (mode & S_IFMT) {
 271	case S_IFIFO:
 272	case S_IFBLK:
 273	case S_IFCHR:
 274	case S_IFSOCK:
 275		if (v9fs_proto_dotl(v9ses)) {
 276			inode->i_op = &v9fs_file_inode_operations_dotl;
 277		} else if (v9fs_proto_dotu(v9ses)) {
 278			inode->i_op = &v9fs_file_inode_operations;
 279		} else {
 280			p9_debug(P9_DEBUG_ERROR,
 281				 "special files without extended mode\n");
 282			err = -EINVAL;
 283			goto error;
 284		}
 285		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 286		break;
 287	case S_IFREG:
 288		if (v9fs_proto_dotl(v9ses)) {
 289			inode->i_op = &v9fs_file_inode_operations_dotl;
 290			if (v9ses->cache == CACHE_LOOSE ||
 291			    v9ses->cache == CACHE_FSCACHE)
 292				inode->i_fop =
 293					&v9fs_cached_file_operations_dotl;
 294			else if (v9ses->cache == CACHE_MMAP)
 295				inode->i_fop = &v9fs_mmap_file_operations_dotl;
 296			else
 297				inode->i_fop = &v9fs_file_operations_dotl;
 298		} else {
 299			inode->i_op = &v9fs_file_inode_operations;
 300			if (v9ses->cache == CACHE_LOOSE ||
 301			    v9ses->cache == CACHE_FSCACHE)
 302				inode->i_fop =
 303					&v9fs_cached_file_operations;
 304			else if (v9ses->cache == CACHE_MMAP)
 305				inode->i_fop = &v9fs_mmap_file_operations;
 306			else
 307				inode->i_fop = &v9fs_file_operations;
 308		}
 309
 310		break;
 311	case S_IFLNK:
 312		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 313			p9_debug(P9_DEBUG_ERROR,
 314				 "extended modes used with legacy protocol\n");
 315			err = -EINVAL;
 316			goto error;
 317		}
 318
 319		if (v9fs_proto_dotl(v9ses))
 320			inode->i_op = &v9fs_symlink_inode_operations_dotl;
 321		else
 322			inode->i_op = &v9fs_symlink_inode_operations;
 323
 324		break;
 325	case S_IFDIR:
 326		inc_nlink(inode);
 327		if (v9fs_proto_dotl(v9ses))
 328			inode->i_op = &v9fs_dir_inode_operations_dotl;
 329		else if (v9fs_proto_dotu(v9ses))
 330			inode->i_op = &v9fs_dir_inode_operations_dotu;
 331		else
 332			inode->i_op = &v9fs_dir_inode_operations;
 333
 334		if (v9fs_proto_dotl(v9ses))
 335			inode->i_fop = &v9fs_dir_operations_dotl;
 336		else
 337			inode->i_fop = &v9fs_dir_operations;
 338
 339		break;
 340	default:
 341		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 342			 mode, mode & S_IFMT);
 343		err = -EINVAL;
 344		goto error;
 345	}
 346
 347	v9fs_set_netfs_context(inode);
 348error:
 349	return err;
 350
 351}
 352
 353/**
 354 * v9fs_get_inode - helper function to setup an inode
 355 * @sb: superblock
 356 * @mode: mode to setup inode with
 357 * @rdev: The device numbers to set
 358 */
 359
 360struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 361{
 362	int err;
 363	struct inode *inode;
 364	struct v9fs_session_info *v9ses = sb->s_fs_info;
 365
 366	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 367
 368	inode = new_inode(sb);
 369	if (!inode) {
 370		pr_warn("%s (%d): Problem allocating inode\n",
 371			__func__, task_pid_nr(current));
 372		return ERR_PTR(-ENOMEM);
 373	}
 374	err = v9fs_init_inode(v9ses, inode, mode, rdev);
 375	if (err) {
 376		iput(inode);
 377		return ERR_PTR(err);
 378	}
 379	return inode;
 380}
 381
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 382/**
 383 * v9fs_evict_inode - Remove an inode from the inode cache
 384 * @inode: inode to release
 385 *
 386 */
 387void v9fs_evict_inode(struct inode *inode)
 388{
 389	struct v9fs_inode *v9inode = V9FS_I(inode);
 390	__le32 version;
 391
 392	truncate_inode_pages_final(&inode->i_data);
 393	version = cpu_to_le32(v9inode->qid.version);
 394	fscache_clear_inode_writeback(v9fs_inode_cookie(v9inode), inode,
 395				      &version);
 396	clear_inode(inode);
 397	filemap_fdatawrite(&inode->i_data);
 398
 399	fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
 
 
 400	/* clunk the fid stashed in writeback_fid */
 401	p9_fid_put(v9inode->writeback_fid);
 402	v9inode->writeback_fid = NULL;
 
 
 403}
 404
 405static int v9fs_test_inode(struct inode *inode, void *data)
 406{
 407	int umode;
 408	dev_t rdev;
 409	struct v9fs_inode *v9inode = V9FS_I(inode);
 410	struct p9_wstat *st = (struct p9_wstat *)data;
 411	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 412
 413	umode = p9mode2unixmode(v9ses, st, &rdev);
 414	/* don't match inode of different type */
 415	if (inode_wrong_type(inode, umode))
 416		return 0;
 417
 418	/* compare qid details */
 419	if (memcmp(&v9inode->qid.version,
 420		   &st->qid.version, sizeof(v9inode->qid.version)))
 421		return 0;
 422
 423	if (v9inode->qid.type != st->qid.type)
 424		return 0;
 425
 426	if (v9inode->qid.path != st->qid.path)
 427		return 0;
 428	return 1;
 429}
 430
 431static int v9fs_test_new_inode(struct inode *inode, void *data)
 432{
 433	return 0;
 434}
 435
 436static int v9fs_set_inode(struct inode *inode,  void *data)
 437{
 438	struct v9fs_inode *v9inode = V9FS_I(inode);
 439	struct p9_wstat *st = (struct p9_wstat *)data;
 440
 441	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 442	return 0;
 443}
 444
 445static struct inode *v9fs_qid_iget(struct super_block *sb,
 446				   struct p9_qid *qid,
 447				   struct p9_wstat *st,
 448				   int new)
 449{
 450	dev_t rdev;
 451	int retval;
 452	umode_t umode;
 453	unsigned long i_ino;
 454	struct inode *inode;
 455	struct v9fs_session_info *v9ses = sb->s_fs_info;
 456	int (*test)(struct inode *inode, void *data);
 457
 458	if (new)
 459		test = v9fs_test_new_inode;
 460	else
 461		test = v9fs_test_inode;
 462
 463	i_ino = v9fs_qid2ino(qid);
 464	inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 465	if (!inode)
 466		return ERR_PTR(-ENOMEM);
 467	if (!(inode->i_state & I_NEW))
 468		return inode;
 469	/*
 470	 * initialize the inode with the stat info
 471	 * FIXME!! we may need support for stale inodes
 472	 * later.
 473	 */
 474	inode->i_ino = i_ino;
 475	umode = p9mode2unixmode(v9ses, st, &rdev);
 476	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 477	if (retval)
 478		goto error;
 479
 480	v9fs_stat2inode(st, inode, sb, 0);
 
 481	v9fs_cache_inode_get_cookie(inode);
 
 482	unlock_new_inode(inode);
 483	return inode;
 484error:
 485	iget_failed(inode);
 
 486	return ERR_PTR(retval);
 487
 488}
 489
 490struct inode *
 491v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 492		    struct super_block *sb, int new)
 493{
 494	struct p9_wstat *st;
 495	struct inode *inode = NULL;
 496
 497	st = p9_client_stat(fid);
 498	if (IS_ERR(st))
 499		return ERR_CAST(st);
 500
 501	inode = v9fs_qid_iget(sb, &st->qid, st, new);
 502	p9stat_free(st);
 503	kfree(st);
 504	return inode;
 505}
 506
 507/**
 508 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 509 * plan 9 AT flag.
 510 * @flags: flags to convert
 511 */
 512static int v9fs_at_to_dotl_flags(int flags)
 513{
 514	int rflags = 0;
 515
 516	if (flags & AT_REMOVEDIR)
 517		rflags |= P9_DOTL_AT_REMOVEDIR;
 518
 519	return rflags;
 520}
 521
 522/**
 523 * v9fs_dec_count - helper functon to drop i_nlink.
 524 *
 525 * If a directory had nlink <= 2 (including . and ..), then we should not drop
 526 * the link count, which indicates the underlying exported fs doesn't maintain
 527 * nlink accurately. e.g.
 528 * - overlayfs sets nlink to 1 for merged dir
 529 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
 530 *   than EXT4_LINK_MAX (65000) links.
 531 *
 532 * @inode: inode whose nlink is being dropped
 533 */
 534static void v9fs_dec_count(struct inode *inode)
 535{
 536	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
 537		drop_nlink(inode);
 538}
 539
 540/**
 541 * v9fs_remove - helper function to remove files and directories
 542 * @dir: directory inode that is being deleted
 543 * @dentry:  dentry that is being deleted
 544 * @flags: removing a directory
 545 *
 546 */
 547
 548static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 549{
 550	struct inode *inode;
 551	int retval = -EOPNOTSUPP;
 552	struct p9_fid *v9fid, *dfid;
 553	struct v9fs_session_info *v9ses;
 554
 555	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 556		 dir, dentry, flags);
 557
 558	v9ses = v9fs_inode2v9ses(dir);
 559	inode = d_inode(dentry);
 560	dfid = v9fs_parent_fid(dentry);
 561	if (IS_ERR(dfid)) {
 562		retval = PTR_ERR(dfid);
 563		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 564		return retval;
 565	}
 566	if (v9fs_proto_dotl(v9ses))
 567		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 568					    v9fs_at_to_dotl_flags(flags));
 569	p9_fid_put(dfid);
 570	if (retval == -EOPNOTSUPP) {
 571		/* Try the one based on path */
 572		v9fid = v9fs_fid_clone(dentry);
 573		if (IS_ERR(v9fid))
 574			return PTR_ERR(v9fid);
 575		retval = p9_client_remove(v9fid);
 576	}
 577	if (!retval) {
 578		/*
 579		 * directories on unlink should have zero
 580		 * link count
 581		 */
 582		if (flags & AT_REMOVEDIR) {
 583			clear_nlink(inode);
 584			v9fs_dec_count(dir);
 585		} else
 586			v9fs_dec_count(inode);
 587
 588		v9fs_invalidate_inode_attr(inode);
 589		v9fs_invalidate_inode_attr(dir);
 590
 591		/* invalidate all fids associated with dentry */
 592		/* NOTE: This will not include open fids */
 593		dentry->d_op->d_release(dentry);
 594	}
 595	return retval;
 596}
 597
 598/**
 599 * v9fs_create - Create a file
 600 * @v9ses: session information
 601 * @dir: directory that dentry is being created in
 602 * @dentry:  dentry that is being created
 603 * @extension: 9p2000.u extension string to support devices, etc.
 604 * @perm: create permissions
 605 * @mode: open mode
 606 *
 607 */
 608static struct p9_fid *
 609v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 610		struct dentry *dentry, char *extension, u32 perm, u8 mode)
 611{
 612	int err;
 613	const unsigned char *name;
 614	struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
 615	struct inode *inode;
 616
 617	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 618
 619	err = 0;
 620	name = dentry->d_name.name;
 621	dfid = v9fs_parent_fid(dentry);
 
 
 622	if (IS_ERR(dfid)) {
 623		err = PTR_ERR(dfid);
 624		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 625		return ERR_PTR(err);
 626	}
 627
 628	/* clone a fid to use for creation */
 629	ofid = clone_fid(dfid);
 630	if (IS_ERR(ofid)) {
 631		err = PTR_ERR(ofid);
 632		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 633		goto error;
 634	}
 635
 636	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 637	if (err < 0) {
 638		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 639		goto error;
 640	}
 641
 642	if (!(perm & P9_DMLINK)) {
 643		/* now walk from the parent so we can get unopened fid */
 644		fid = p9_client_walk(dfid, 1, &name, 1);
 645		if (IS_ERR(fid)) {
 646			err = PTR_ERR(fid);
 647			p9_debug(P9_DEBUG_VFS,
 648				   "p9_client_walk failed %d\n", err);
 
 649			goto error;
 650		}
 651		/*
 652		 * instantiate inode and assign the unopened fid to the dentry
 653		 */
 654		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 655		if (IS_ERR(inode)) {
 656			err = PTR_ERR(inode);
 657			p9_debug(P9_DEBUG_VFS,
 658				   "inode creation failed %d\n", err);
 659			goto error;
 660		}
 661		v9fs_fid_add(dentry, &fid);
 
 
 662		d_instantiate(dentry, inode);
 663	}
 664	p9_fid_put(dfid);
 665	return ofid;
 666error:
 667	p9_fid_put(dfid);
 668	p9_fid_put(ofid);
 669	p9_fid_put(fid);
 
 
 
 670	return ERR_PTR(err);
 671}
 672
 673/**
 674 * v9fs_vfs_create - VFS hook to create a regular file
 675 * @mnt_userns: The user namespace of the mount
 676 * @dir: The parent directory
 677 * @dentry: The name of file to be created
 678 * @mode: The UNIX file mode to set
 679 * @excl: True if the file must not yet exist
 680 *
 681 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 682 * for mknod(2).
 683 *
 684 */
 685
 686static int
 687v9fs_vfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 688		struct dentry *dentry, umode_t mode, bool excl)
 689{
 690	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 691	u32 perm = unixmode2p9mode(v9ses, mode);
 692	struct p9_fid *fid;
 
 
 
 
 
 
 
 
 
 
 
 
 
 693
 694	/* P9_OEXCL? */
 695	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 696	if (IS_ERR(fid))
 697		return PTR_ERR(fid);
 
 
 
 
 698
 699	v9fs_invalidate_inode_attr(dir);
 700	p9_fid_put(fid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 701
 702	return 0;
 
 
 
 
 
 
 703}
 704
 705/**
 706 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 707 * @mnt_userns: The user namespace of the mount
 708 * @dir:  inode that is being unlinked
 709 * @dentry: dentry that is being unlinked
 710 * @mode: mode for new directory
 711 *
 712 */
 713
 714static int v9fs_vfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 715			  struct dentry *dentry, umode_t mode)
 716{
 717	int err;
 718	u32 perm;
 719	struct p9_fid *fid;
 720	struct v9fs_session_info *v9ses;
 721
 722	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 723	err = 0;
 724	v9ses = v9fs_inode2v9ses(dir);
 725	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 726	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 727	if (IS_ERR(fid)) {
 728		err = PTR_ERR(fid);
 729		fid = NULL;
 730	} else {
 731		inc_nlink(dir);
 732		v9fs_invalidate_inode_attr(dir);
 733	}
 734
 735	if (fid)
 736		p9_fid_put(fid);
 737
 738	return err;
 739}
 740
 741/**
 742 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 743 * @dir:  inode that is being walked from
 744 * @dentry: dentry that is being walked to?
 745 * @flags: lookup flags (unused)
 746 *
 747 */
 748
 749struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 750				      unsigned int flags)
 751{
 752	struct dentry *res;
 
 753	struct v9fs_session_info *v9ses;
 754	struct p9_fid *dfid, *fid;
 755	struct inode *inode;
 756	const unsigned char *name;
 
 757
 758	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
 759		 dir, dentry, dentry, flags);
 760
 761	if (dentry->d_name.len > NAME_MAX)
 762		return ERR_PTR(-ENAMETOOLONG);
 763
 
 764	v9ses = v9fs_inode2v9ses(dir);
 765	/* We can walk d_parent because we hold the dir->i_mutex */
 766	dfid = v9fs_parent_fid(dentry);
 767	if (IS_ERR(dfid))
 768		return ERR_CAST(dfid);
 769
 
 
 
 
 
 
 
 
 
 
 
 770	/*
 771	 * Make sure we don't use a wrong inode due to parallel
 772	 * unlink. For cached mode create calls request for new
 773	 * inode. But with cache disabled, lookup should do this.
 774	 */
 775	name = dentry->d_name.name;
 776	fid = p9_client_walk(dfid, 1, &name, 1);
 777	p9_fid_put(dfid);
 778	if (fid == ERR_PTR(-ENOENT))
 779		inode = NULL;
 780	else if (IS_ERR(fid))
 781		inode = ERR_CAST(fid);
 782	else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 783		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 784	else
 785		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 
 
 
 
 
 
 
 
 
 786	/*
 787	 * If we had a rename on the server and a parallel lookup
 788	 * for the new name, then make sure we instantiate with
 789	 * the new name. ie look up for a/b, while on server somebody
 790	 * moved b under k and client parallely did a lookup for
 791	 * k/b.
 792	 */
 793	res = d_splice_alias(inode, dentry);
 794	if (!IS_ERR(fid)) {
 795		if (!res)
 796			v9fs_fid_add(dentry, &fid);
 797		else if (!IS_ERR(res))
 798			v9fs_fid_add(res, &fid);
 799		else
 800			p9_fid_put(fid);
 801	}
 802	return res;
 803}
 804
 805static int
 806v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 807		     struct file *file, unsigned int flags, umode_t mode)
 808{
 809	int err;
 810	u32 perm;
 811	struct v9fs_inode *v9inode;
 812	struct v9fs_session_info *v9ses;
 813	struct p9_fid *fid, *inode_fid;
 814	struct dentry *res = NULL;
 815	struct inode *inode;
 816
 817	if (d_in_lookup(dentry)) {
 818		res = v9fs_vfs_lookup(dir, dentry, 0);
 819		if (IS_ERR(res))
 820			return PTR_ERR(res);
 821
 822		if (res)
 823			dentry = res;
 824	}
 825
 826	/* Only creates */
 827	if (!(flags & O_CREAT) || d_really_is_positive(dentry))
 828		return finish_no_open(file, res);
 829
 830	err = 0;
 831
 832	v9ses = v9fs_inode2v9ses(dir);
 833	perm = unixmode2p9mode(v9ses, mode);
 834	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 835				v9fs_uflags2omode(flags,
 836						v9fs_proto_dotu(v9ses)));
 837	if (IS_ERR(fid)) {
 838		err = PTR_ERR(fid);
 839		goto error;
 840	}
 841
 842	v9fs_invalidate_inode_attr(dir);
 843	inode = d_inode(dentry);
 844	v9inode = V9FS_I(inode);
 845	mutex_lock(&v9inode->v_mutex);
 846	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
 847	    !v9inode->writeback_fid &&
 848	    ((flags & O_ACCMODE) != O_RDONLY)) {
 849		/*
 850		 * clone a fid and add it to writeback_fid
 851		 * we do it during open time instead of
 852		 * page dirty time via write_begin/page_mkwrite
 853		 * because we want write after unlink usecase
 854		 * to work.
 855		 */
 856		inode_fid = v9fs_writeback_fid(dentry);
 857		if (IS_ERR(inode_fid)) {
 858			err = PTR_ERR(inode_fid);
 859			mutex_unlock(&v9inode->v_mutex);
 860			goto error;
 861		}
 862		v9inode->writeback_fid = (void *) inode_fid;
 863	}
 864	mutex_unlock(&v9inode->v_mutex);
 865	err = finish_open(file, dentry, generic_file_open);
 866	if (err)
 867		goto error;
 868
 869	file->private_data = fid;
 870	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 871		fscache_use_cookie(v9fs_inode_cookie(v9inode),
 872				   file->f_mode & FMODE_WRITE);
 873	v9fs_open_fid_add(inode, &fid);
 874
 875	file->f_mode |= FMODE_CREATED;
 876out:
 877	dput(res);
 878	return err;
 879
 880error:
 881	p9_fid_put(fid);
 882	goto out;
 883}
 884
 885/**
 886 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 887 * @i:  inode that is being unlinked
 888 * @d: dentry that is being unlinked
 889 *
 890 */
 891
 892int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 893{
 894	return v9fs_remove(i, d, 0);
 895}
 896
 897/**
 898 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 899 * @i:  inode that is being unlinked
 900 * @d: dentry that is being unlinked
 901 *
 902 */
 903
 904int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 905{
 906	return v9fs_remove(i, d, AT_REMOVEDIR);
 907}
 908
 909/**
 910 * v9fs_vfs_rename - VFS hook to rename an inode
 911 * @mnt_userns: The user namespace of the mount
 912 * @old_dir:  old dir inode
 913 * @old_dentry: old dentry
 914 * @new_dir: new dir inode
 915 * @new_dentry: new dentry
 916 * @flags: RENAME_* flags
 917 *
 918 */
 919
 920int
 921v9fs_vfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 922		struct dentry *old_dentry, struct inode *new_dir,
 923		struct dentry *new_dentry, unsigned int flags)
 924{
 925	int retval;
 926	struct inode *old_inode;
 927	struct inode *new_inode;
 928	struct v9fs_session_info *v9ses;
 929	struct p9_fid *oldfid = NULL, *dfid = NULL;
 930	struct p9_fid *olddirfid = NULL;
 931	struct p9_fid *newdirfid = NULL;
 932	struct p9_wstat wstat;
 933
 934	if (flags)
 935		return -EINVAL;
 936
 937	p9_debug(P9_DEBUG_VFS, "\n");
 938	retval = 0;
 939	old_inode = d_inode(old_dentry);
 940	new_inode = d_inode(new_dentry);
 941	v9ses = v9fs_inode2v9ses(old_inode);
 942	oldfid = v9fs_fid_lookup(old_dentry);
 943	if (IS_ERR(oldfid))
 944		return PTR_ERR(oldfid);
 945
 946	dfid = v9fs_parent_fid(old_dentry);
 947	olddirfid = clone_fid(dfid);
 948	p9_fid_put(dfid);
 949	dfid = NULL;
 950
 951	if (IS_ERR(olddirfid)) {
 952		retval = PTR_ERR(olddirfid);
 953		goto error;
 954	}
 955
 956	dfid = v9fs_parent_fid(new_dentry);
 957	newdirfid = clone_fid(dfid);
 958	p9_fid_put(dfid);
 959	dfid = NULL;
 960
 961	if (IS_ERR(newdirfid)) {
 962		retval = PTR_ERR(newdirfid);
 963		goto error;
 964	}
 965
 966	down_write(&v9ses->rename_sem);
 967	if (v9fs_proto_dotl(v9ses)) {
 968		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 969					    newdirfid, new_dentry->d_name.name);
 970		if (retval == -EOPNOTSUPP)
 971			retval = p9_client_rename(oldfid, newdirfid,
 972						  new_dentry->d_name.name);
 973		if (retval != -EOPNOTSUPP)
 974			goto error_locked;
 975	}
 976	if (old_dentry->d_parent != new_dentry->d_parent) {
 977		/*
 978		 * 9P .u can only handle file rename in the same directory
 979		 */
 980
 981		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 982		retval = -EXDEV;
 983		goto error_locked;
 984	}
 985	v9fs_blank_wstat(&wstat);
 986	wstat.muid = v9ses->uname;
 987	wstat.name = new_dentry->d_name.name;
 988	retval = p9_client_wstat(oldfid, &wstat);
 989
 990error_locked:
 991	if (!retval) {
 992		if (new_inode) {
 993			if (S_ISDIR(new_inode->i_mode))
 994				clear_nlink(new_inode);
 995			else
 996				v9fs_dec_count(new_inode);
 997		}
 998		if (S_ISDIR(old_inode->i_mode)) {
 999			if (!new_inode)
1000				inc_nlink(new_dir);
1001			v9fs_dec_count(old_dir);
1002		}
1003		v9fs_invalidate_inode_attr(old_inode);
1004		v9fs_invalidate_inode_attr(old_dir);
1005		v9fs_invalidate_inode_attr(new_dir);
1006
1007		/* successful rename */
1008		d_move(old_dentry, new_dentry);
1009	}
1010	up_write(&v9ses->rename_sem);
 
 
 
 
1011
1012error:
1013	p9_fid_put(newdirfid);
1014	p9_fid_put(olddirfid);
1015	p9_fid_put(oldfid);
1016	return retval;
1017}
1018
1019/**
1020 * v9fs_vfs_getattr - retrieve file metadata
1021 * @mnt_userns: The user namespace of the mount
1022 * @path: Object to query
1023 * @stat: metadata structure to populate
1024 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
1025 * @flags: AT_STATX_xxx setting
1026 *
1027 */
1028
1029static int
1030v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
1031		 struct kstat *stat, u32 request_mask, unsigned int flags)
1032{
1033	struct dentry *dentry = path->dentry;
1034	struct v9fs_session_info *v9ses;
1035	struct p9_fid *fid;
1036	struct p9_wstat *st;
1037
1038	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 
1039	v9ses = v9fs_dentry2v9ses(dentry);
1040	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1041		generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1042		return 0;
1043	}
1044	fid = v9fs_fid_lookup(dentry);
1045	if (IS_ERR(fid))
1046		return PTR_ERR(fid);
1047
1048	st = p9_client_stat(fid);
1049	p9_fid_put(fid);
1050	if (IS_ERR(st))
1051		return PTR_ERR(st);
1052
1053	v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1054	generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1055
1056	p9stat_free(st);
1057	kfree(st);
1058	return 0;
1059}
1060
1061/**
1062 * v9fs_vfs_setattr - set file metadata
1063 * @mnt_userns: The user namespace of the mount
1064 * @dentry: file whose metadata to set
1065 * @iattr: metadata assignment structure
1066 *
1067 */
1068
1069static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
1070			    struct dentry *dentry, struct iattr *iattr)
1071{
1072	int retval, use_dentry = 0;
1073	struct inode *inode = d_inode(dentry);
1074	struct v9fs_inode *v9inode = V9FS_I(inode);
1075	struct v9fs_session_info *v9ses;
1076	struct p9_fid *fid = NULL;
1077	struct p9_wstat wstat;
1078
1079	p9_debug(P9_DEBUG_VFS, "\n");
1080	retval = setattr_prepare(&init_user_ns, dentry, iattr);
1081	if (retval)
1082		return retval;
1083
1084	retval = -EPERM;
1085	v9ses = v9fs_dentry2v9ses(dentry);
1086	if (iattr->ia_valid & ATTR_FILE) {
1087		fid = iattr->ia_file->private_data;
1088		WARN_ON(!fid);
1089	}
1090	if (!fid) {
1091		fid = v9fs_fid_lookup(dentry);
1092		use_dentry = 1;
1093	}
1094	if (IS_ERR(fid))
1095		return PTR_ERR(fid);
1096
1097	v9fs_blank_wstat(&wstat);
1098	if (iattr->ia_valid & ATTR_MODE)
1099		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1100
1101	if (iattr->ia_valid & ATTR_MTIME)
1102		wstat.mtime = iattr->ia_mtime.tv_sec;
1103
1104	if (iattr->ia_valid & ATTR_ATIME)
1105		wstat.atime = iattr->ia_atime.tv_sec;
1106
1107	if (iattr->ia_valid & ATTR_SIZE)
1108		wstat.length = iattr->ia_size;
1109
1110	if (v9fs_proto_dotu(v9ses)) {
1111		if (iattr->ia_valid & ATTR_UID)
1112			wstat.n_uid = iattr->ia_uid;
1113
1114		if (iattr->ia_valid & ATTR_GID)
1115			wstat.n_gid = iattr->ia_gid;
1116	}
1117
1118	/* Write all dirty data */
1119	if (d_is_reg(dentry))
1120		filemap_write_and_wait(inode->i_mapping);
1121
1122	retval = p9_client_wstat(fid, &wstat);
1123
1124	if (use_dentry)
1125		p9_fid_put(fid);
1126
1127	if (retval < 0)
1128		return retval;
1129
1130	if ((iattr->ia_valid & ATTR_SIZE) &&
1131	    iattr->ia_size != i_size_read(inode)) {
1132		truncate_setsize(inode, iattr->ia_size);
1133		fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1134	}
1135
1136	v9fs_invalidate_inode_attr(inode);
1137
1138	setattr_copy(&init_user_ns, inode, iattr);
1139	mark_inode_dirty(inode);
1140	return 0;
1141}
1142
1143/**
1144 * v9fs_stat2inode - populate an inode structure with mistat info
1145 * @stat: Plan 9 metadata (mistat) structure
1146 * @inode: inode to populate
1147 * @sb: superblock of filesystem
1148 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1149 *
1150 */
1151
1152void
1153v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1154		 struct super_block *sb, unsigned int flags)
1155{
1156	umode_t mode;
 
 
 
1157	struct v9fs_session_info *v9ses = sb->s_fs_info;
1158	struct v9fs_inode *v9inode = V9FS_I(inode);
1159
1160	set_nlink(inode, 1);
1161
1162	inode->i_atime.tv_sec = stat->atime;
1163	inode->i_mtime.tv_sec = stat->mtime;
1164	inode->i_ctime.tv_sec = stat->mtime;
1165
1166	inode->i_uid = v9ses->dfltuid;
1167	inode->i_gid = v9ses->dfltgid;
1168
1169	if (v9fs_proto_dotu(v9ses)) {
1170		inode->i_uid = stat->n_uid;
1171		inode->i_gid = stat->n_gid;
1172	}
1173	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1174		if (v9fs_proto_dotu(v9ses)) {
1175			unsigned int i_nlink;
1176			/*
1177			 * Hadlink support got added later to the .u extension.
1178			 * So there can be a server out there that doesn't
1179			 * support this even with .u extension. That would
1180			 * just leave us with stat->extension being an empty
1181			 * string, though.
1182			 */
 
1183			/* HARDLINKCOUNT %u */
1184			if (sscanf(stat->extension,
1185				   " HARDLINKCOUNT %u", &i_nlink) == 1)
1186				set_nlink(inode, i_nlink);
1187		}
1188	}
1189	mode = p9mode2perm(v9ses, stat);
1190	mode |= inode->i_mode & ~S_IALLUGO;
1191	inode->i_mode = mode;
 
1192
1193	if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1194		v9fs_i_size_write(inode, stat->length);
1195	/* not real number of blocks, but 512 byte ones ... */
1196	inode->i_blocks = (stat->length + 512 - 1) >> 9;
1197	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1198}
1199
1200/**
1201 * v9fs_qid2ino - convert qid into inode number
1202 * @qid: qid to hash
1203 *
1204 * BUG: potential for inode number collisions?
1205 */
1206
1207ino_t v9fs_qid2ino(struct p9_qid *qid)
1208{
1209	u64 path = qid->path + 2;
1210	ino_t i = 0;
1211
1212	if (sizeof(ino_t) == sizeof(path))
1213		memcpy(&i, &path, sizeof(ino_t));
1214	else
1215		i = (ino_t) (path ^ (path >> 32));
1216
1217	return i;
1218}
1219
1220/**
1221 * v9fs_vfs_get_link - follow a symlink path
1222 * @dentry: dentry for symlink
1223 * @inode: inode for symlink
1224 * @done: delayed call for when we are done with the return value
 
1225 */
1226
1227static const char *v9fs_vfs_get_link(struct dentry *dentry,
1228				     struct inode *inode,
1229				     struct delayed_call *done)
1230{
 
 
1231	struct v9fs_session_info *v9ses;
1232	struct p9_fid *fid;
1233	struct p9_wstat *st;
1234	char *res;
1235
1236	if (!dentry)
1237		return ERR_PTR(-ECHILD);
1238
 
 
1239	v9ses = v9fs_dentry2v9ses(dentry);
1240	if (!v9fs_proto_dotu(v9ses))
1241		return ERR_PTR(-EBADF);
1242
1243	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1244	fid = v9fs_fid_lookup(dentry);
 
 
1245
1246	if (IS_ERR(fid))
1247		return ERR_CAST(fid);
1248
1249	st = p9_client_stat(fid);
1250	p9_fid_put(fid);
1251	if (IS_ERR(st))
1252		return ERR_CAST(st);
1253
1254	if (!(st->mode & P9_DMSYMLINK)) {
1255		p9stat_free(st);
1256		kfree(st);
1257		return ERR_PTR(-EINVAL);
1258	}
1259	res = st->extension;
1260	st->extension = NULL;
1261	if (strlen(res) >= PATH_MAX)
1262		res[PATH_MAX - 1] = '\0';
1263
 
 
 
 
 
 
 
 
1264	p9stat_free(st);
1265	kfree(st);
1266	set_delayed_call(done, kfree_link, res);
1267	return res;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1268}
1269
1270/**
1271 * v9fs_vfs_mkspecial - create a special file
1272 * @dir: inode to create special file in
1273 * @dentry: dentry to create
1274 * @perm: mode to create special file
1275 * @extension: 9p2000.u format extension string representing special file
1276 *
1277 */
1278
1279static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1280	u32 perm, const char *extension)
1281{
1282	struct p9_fid *fid;
1283	struct v9fs_session_info *v9ses;
1284
1285	v9ses = v9fs_inode2v9ses(dir);
1286	if (!v9fs_proto_dotu(v9ses)) {
1287		p9_debug(P9_DEBUG_ERROR, "not extended\n");
1288		return -EPERM;
1289	}
1290
1291	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1292								P9_OREAD);
1293	if (IS_ERR(fid))
1294		return PTR_ERR(fid);
1295
1296	v9fs_invalidate_inode_attr(dir);
1297	p9_fid_put(fid);
1298	return 0;
1299}
1300
1301/**
1302 * v9fs_vfs_symlink - helper function to create symlinks
1303 * @mnt_userns: The user namespace of the mount
1304 * @dir: directory inode containing symlink
1305 * @dentry: dentry for symlink
1306 * @symname: symlink data
1307 *
1308 * See Also: 9P2000.u RFC for more information
1309 *
1310 */
1311
1312static int
1313v9fs_vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
1314		 struct dentry *dentry, const char *symname)
1315{
1316	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1317		 dir->i_ino, dentry, symname);
1318
1319	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1320}
1321
1322#define U32_MAX_DIGITS 10
1323
1324/**
1325 * v9fs_vfs_link - create a hardlink
1326 * @old_dentry: dentry for file to link to
1327 * @dir: inode destination for new link
1328 * @dentry: dentry for link
1329 *
1330 */
1331
1332static int
1333v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1334	      struct dentry *dentry)
1335{
1336	int retval;
1337	char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1338	struct p9_fid *oldfid;
1339
1340	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1341		 dir->i_ino, dentry, old_dentry);
1342
1343	oldfid = v9fs_fid_clone(old_dentry);
1344	if (IS_ERR(oldfid))
1345		return PTR_ERR(oldfid);
1346
 
 
 
 
 
 
1347	sprintf(name, "%d\n", oldfid->fid);
1348	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
 
1349	if (!retval) {
1350		v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1351		v9fs_invalidate_inode_attr(dir);
1352	}
1353	p9_fid_put(oldfid);
 
1354	return retval;
1355}
1356
1357/**
1358 * v9fs_vfs_mknod - create a special file
1359 * @mnt_userns: The user namespace of the mount
1360 * @dir: inode destination for new link
1361 * @dentry: dentry for file
1362 * @mode: mode for creation
1363 * @rdev: device associated with special file
1364 *
1365 */
1366
1367static int
1368v9fs_vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
1369	       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: %x 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	struct p9_wstat *st;
1399	struct v9fs_session_info *v9ses;
1400	unsigned int flags;
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_wrong_type(inode, umode))
1411		goto out;
1412
 
1413	/*
1414	 * We don't want to refresh inode->i_size,
1415	 * because we may have cached data
1416	 */
1417	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1418		V9FS_STAT2INODE_KEEP_ISIZE : 0;
1419	v9fs_stat2inode(st, inode, inode->i_sb, flags);
 
 
1420out:
1421	p9stat_free(st);
1422	kfree(st);
1423	return 0;
1424}
1425
1426static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1427	.create = v9fs_vfs_create,
1428	.lookup = v9fs_vfs_lookup,
1429	.atomic_open = v9fs_vfs_atomic_open,
1430	.symlink = v9fs_vfs_symlink,
1431	.link = v9fs_vfs_link,
1432	.unlink = v9fs_vfs_unlink,
1433	.mkdir = v9fs_vfs_mkdir,
1434	.rmdir = v9fs_vfs_rmdir,
1435	.mknod = v9fs_vfs_mknod,
1436	.rename = v9fs_vfs_rename,
1437	.getattr = v9fs_vfs_getattr,
1438	.setattr = v9fs_vfs_setattr,
1439};
1440
1441static const struct inode_operations v9fs_dir_inode_operations = {
1442	.create = v9fs_vfs_create,
1443	.lookup = v9fs_vfs_lookup,
1444	.atomic_open = v9fs_vfs_atomic_open,
1445	.unlink = v9fs_vfs_unlink,
1446	.mkdir = v9fs_vfs_mkdir,
1447	.rmdir = v9fs_vfs_rmdir,
1448	.mknod = v9fs_vfs_mknod,
1449	.rename = v9fs_vfs_rename,
1450	.getattr = v9fs_vfs_getattr,
1451	.setattr = v9fs_vfs_setattr,
1452};
1453
1454static const struct inode_operations v9fs_file_inode_operations = {
1455	.getattr = v9fs_vfs_getattr,
1456	.setattr = v9fs_vfs_setattr,
1457};
1458
1459static const struct inode_operations v9fs_symlink_inode_operations = {
1460	.get_link = v9fs_vfs_get_link,
 
 
1461	.getattr = v9fs_vfs_getattr,
1462	.setattr = v9fs_vfs_setattr,
1463};
1464