vfs_inode.c

   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 & 0777; /* S_IRWXUGO */
  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 (uflags & O_TRUNC)
 182		ret |= P9_OTRUNC;
 183
 184	if (extended) {
 185		if (uflags & O_EXCL)
 186			ret |= P9_OEXCL;
 187
 188		if (uflags & O_APPEND)
 189			ret |= P9_OAPPEND;
 190	}
 191
 192	return ret;
 193}
 194
 195/**
 196 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 197 * @wstat: structure to initialize
 198 *
 199 */
 200
 201void
 202v9fs_blank_wstat(struct p9_wstat *wstat)
 203{
 204	wstat->type = ~0;
 205	wstat->dev = ~0;
 206	wstat->qid.type = ~0;
 207	wstat->qid.version = ~0;
 208	*((long long *)&wstat->qid.path) = ~0;
 209	wstat->mode = ~0;
 210	wstat->atime = ~0;
 211	wstat->mtime = ~0;
 212	wstat->length = ~0;
 213	wstat->name = NULL;
 214	wstat->uid = NULL;
 215	wstat->gid = NULL;
 216	wstat->muid = NULL;
 217	wstat->n_uid = INVALID_UID;
 218	wstat->n_gid = INVALID_GID;
 219	wstat->n_muid = INVALID_UID;
 220	wstat->extension = NULL;
 221}
 222
 223/**
 224 * v9fs_alloc_inode - helper function to allocate an inode
 225 * @sb: The superblock to allocate the inode from
 226 */
 227struct inode *v9fs_alloc_inode(struct super_block *sb)
 228{
 229	struct v9fs_inode *v9inode;
 230
 231	v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL);
 232	if (!v9inode)
 233		return 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 */
 252void 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, true);
 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(&nop_mnt_idmap, inode, NULL, mode);
 264	inode->i_blocks = 0;
 265	inode->i_rdev = rdev;
 266	simple_inode_init_ts(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			inode->i_fop = &v9fs_file_operations_dotl;
 291		} else {
 292			inode->i_op = &v9fs_file_inode_operations;
 293			inode->i_fop = &v9fs_file_operations;
 294		}
 295
 296		break;
 297	case S_IFLNK:
 298		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 299			p9_debug(P9_DEBUG_ERROR,
 300				 "extended modes used with legacy protocol\n");
 301			err = -EINVAL;
 302			goto error;
 303		}
 304
 305		if (v9fs_proto_dotl(v9ses))
 306			inode->i_op = &v9fs_symlink_inode_operations_dotl;
 307		else
 308			inode->i_op = &v9fs_symlink_inode_operations;
 309
 310		break;
 311	case S_IFDIR:
 312		inc_nlink(inode);
 313		if (v9fs_proto_dotl(v9ses))
 314			inode->i_op = &v9fs_dir_inode_operations_dotl;
 315		else if (v9fs_proto_dotu(v9ses))
 316			inode->i_op = &v9fs_dir_inode_operations_dotu;
 317		else
 318			inode->i_op = &v9fs_dir_inode_operations;
 319
 320		if (v9fs_proto_dotl(v9ses))
 321			inode->i_fop = &v9fs_dir_operations_dotl;
 322		else
 323			inode->i_fop = &v9fs_dir_operations;
 324
 325		break;
 326	default:
 327		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 328			 mode, mode & S_IFMT);
 329		err = -EINVAL;
 330		goto error;
 331	}
 332error:
 333	return err;
 334
 335}
 336
 337/**
 338 * v9fs_evict_inode - Remove an inode from the inode cache
 339 * @inode: inode to release
 340 *
 341 */
 342void v9fs_evict_inode(struct inode *inode)
 343{
 344	struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode);
 345	__le32 __maybe_unused version;
 346
 347	if (!is_bad_inode(inode)) {
 348		netfs_wait_for_outstanding_io(inode);
 349		truncate_inode_pages_final(&inode->i_data);
 350
 351		version = cpu_to_le32(v9inode->qid.version);
 352		netfs_clear_inode_writeback(inode, &version);
 353
 354		clear_inode(inode);
 355		filemap_fdatawrite(&inode->i_data);
 356
 357#ifdef CONFIG_9P_FSCACHE
 358		if (v9fs_inode_cookie(v9inode))
 359			fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
 360#endif
 361	} else
 362		clear_inode(inode);
 363}
 364
 365static int v9fs_test_inode(struct inode *inode, void *data)
 366{
 367	int umode;
 368	dev_t rdev;
 369	struct v9fs_inode *v9inode = V9FS_I(inode);
 370	struct p9_wstat *st = (struct p9_wstat *)data;
 371	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 372
 373	umode = p9mode2unixmode(v9ses, st, &rdev);
 374	/* don't match inode of different type */
 375	if (inode_wrong_type(inode, umode))
 376		return 0;
 377
 378	/* compare qid details */
 379	if (memcmp(&v9inode->qid.version,
 380		   &st->qid.version, sizeof(v9inode->qid.version)))
 381		return 0;
 382
 383	if (v9inode->qid.type != st->qid.type)
 384		return 0;
 385
 386	if (v9inode->qid.path != st->qid.path)
 387		return 0;
 388	return 1;
 389}
 390
 391static int v9fs_test_new_inode(struct inode *inode, void *data)
 392{
 393	return 0;
 394}
 395
 396static int v9fs_set_inode(struct inode *inode,  void *data)
 397{
 398	struct v9fs_inode *v9inode = V9FS_I(inode);
 399	struct p9_wstat *st = (struct p9_wstat *)data;
 400
 401	memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 402	return 0;
 403}
 404
 405static struct inode *v9fs_qid_iget(struct super_block *sb,
 406				   struct p9_qid *qid,
 407				   struct p9_wstat *st,
 408				   int new)
 409{
 410	dev_t rdev;
 411	int retval;
 412	umode_t umode;
 413	struct inode *inode;
 414	struct v9fs_session_info *v9ses = sb->s_fs_info;
 415	int (*test)(struct inode *inode, void *data);
 416
 417	if (new)
 418		test = v9fs_test_new_inode;
 419	else
 420		test = v9fs_test_inode;
 421
 422	inode = iget5_locked(sb, QID2INO(qid), test, v9fs_set_inode, st);
 423	if (!inode)
 424		return ERR_PTR(-ENOMEM);
 425	if (!(inode_state_read_once(inode) & I_NEW))
 426		return inode;
 427	/*
 428	 * initialize the inode with the stat info
 429	 * FIXME!! we may need support for stale inodes
 430	 * later.
 431	 */
 432	inode->i_ino = QID2INO(qid);
 433	umode = p9mode2unixmode(v9ses, st, &rdev);
 434	retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 435	if (retval)
 436		goto error;
 437
 438	v9fs_stat2inode(st, inode, sb, 0);
 439	v9fs_set_netfs_context(inode);
 440	v9fs_cache_inode_get_cookie(inode);
 441	unlock_new_inode(inode);
 442	return inode;
 443error:
 444	iget_failed(inode);
 445	return ERR_PTR(retval);
 446
 447}
 448
 449struct inode *
 450v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 451		    struct super_block *sb, int new)
 452{
 453	struct p9_wstat *st;
 454	struct inode *inode = NULL;
 455
 456	st = p9_client_stat(fid);
 457	if (IS_ERR(st))
 458		return ERR_CAST(st);
 459
 460	inode = v9fs_qid_iget(sb, &st->qid, st, new);
 461	p9stat_free(st);
 462	kfree(st);
 463	return inode;
 464}
 465
 466/**
 467 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 468 * plan 9 AT flag.
 469 * @flags: flags to convert
 470 */
 471static int v9fs_at_to_dotl_flags(int flags)
 472{
 473	int rflags = 0;
 474
 475	if (flags & AT_REMOVEDIR)
 476		rflags |= P9_DOTL_AT_REMOVEDIR;
 477
 478	return rflags;
 479}
 480
 481/**
 482 * v9fs_dec_count - helper functon to drop i_nlink.
 483 *
 484 * If a directory had nlink <= 2 (including . and ..), then we should not drop
 485 * the link count, which indicates the underlying exported fs doesn't maintain
 486 * nlink accurately. e.g.
 487 * - overlayfs sets nlink to 1 for merged dir
 488 * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
 489 *   than EXT4_LINK_MAX (65000) links.
 490 *
 491 * @inode: inode whose nlink is being dropped
 492 */
 493static void v9fs_dec_count(struct inode *inode)
 494{
 495	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
 496		drop_nlink(inode);
 497}
 498
 499/**
 500 * v9fs_remove - helper function to remove files and directories
 501 * @dir: directory inode that is being deleted
 502 * @dentry:  dentry that is being deleted
 503 * @flags: removing a directory
 504 *
 505 */
 506
 507static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 508{
 509	struct inode *inode;
 510	int retval = -EOPNOTSUPP;
 511	struct p9_fid *v9fid, *dfid;
 512	struct v9fs_session_info *v9ses;
 513
 514	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 515		 dir, dentry, flags);
 516
 517	v9ses = v9fs_inode2v9ses(dir);
 518	inode = d_inode(dentry);
 519	dfid = v9fs_parent_fid(dentry);
 520	if (IS_ERR(dfid)) {
 521		retval = PTR_ERR(dfid);
 522		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 523		return retval;
 524	}
 525	if (v9fs_proto_dotl(v9ses))
 526		retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 527					    v9fs_at_to_dotl_flags(flags));
 528	p9_fid_put(dfid);
 529	if (retval == -EOPNOTSUPP) {
 530		/* Try the one based on path */
 531		v9fid = v9fs_fid_clone(dentry);
 532		if (IS_ERR(v9fid))
 533			return PTR_ERR(v9fid);
 534		retval = p9_client_remove(v9fid);
 535	}
 536	if (!retval) {
 537		/*
 538		 * directories on unlink should have zero
 539		 * link count
 540		 */
 541		if (flags & AT_REMOVEDIR) {
 542			clear_nlink(inode);
 543			v9fs_dec_count(dir);
 544		} else
 545			v9fs_dec_count(inode);
 546
 547		v9fs_invalidate_inode_attr(inode);
 548		v9fs_invalidate_inode_attr(dir);
 549
 550		/* invalidate all fids associated with dentry */
 551		/* NOTE: This will not include open fids */
 552		dentry->d_op->d_release(dentry);
 553	}
 554	return retval;
 555}
 556
 557/**
 558 * v9fs_create - Create a file
 559 * @v9ses: session information
 560 * @dir: directory that dentry is being created in
 561 * @dentry:  dentry that is being created
 562 * @extension: 9p2000.u extension string to support devices, etc.
 563 * @perm: create permissions
 564 * @mode: open mode
 565 *
 566 */
 567static struct p9_fid *
 568v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 569		struct dentry *dentry, char *extension, u32 perm, u8 mode)
 570{
 571	int err;
 572	const unsigned char *name;
 573	struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
 574	struct inode *inode;
 575
 576	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 577
 578	name = dentry->d_name.name;
 579	dfid = v9fs_parent_fid(dentry);
 580	if (IS_ERR(dfid)) {
 581		err = PTR_ERR(dfid);
 582		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 583		return ERR_PTR(err);
 584	}
 585
 586	/* clone a fid to use for creation */
 587	ofid = clone_fid(dfid);
 588	if (IS_ERR(ofid)) {
 589		err = PTR_ERR(ofid);
 590		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 591		goto error;
 592	}
 593
 594	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 595	if (err < 0) {
 596		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 597		goto error;
 598	}
 599
 600	if (!(perm & P9_DMLINK)) {
 601		/* now walk from the parent so we can get unopened fid */
 602		fid = p9_client_walk(dfid, 1, &name, 1);
 603		if (IS_ERR(fid)) {
 604			err = PTR_ERR(fid);
 605			p9_debug(P9_DEBUG_VFS,
 606				   "p9_client_walk failed %d\n", err);
 607			goto error;
 608		}
 609		/*
 610		 * instantiate inode and assign the unopened fid to the dentry
 611		 */
 612		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 613		if (IS_ERR(inode)) {
 614			err = PTR_ERR(inode);
 615			p9_debug(P9_DEBUG_VFS,
 616				   "inode creation failed %d\n", err);
 617			goto error;
 618		}
 619		v9fs_fid_add(dentry, &fid);
 620		d_instantiate(dentry, inode);
 621	}
 622	p9_fid_put(dfid);
 623	return ofid;
 624error:
 625	p9_fid_put(dfid);
 626	p9_fid_put(ofid);
 627	p9_fid_put(fid);
 628	return ERR_PTR(err);
 629}
 630
 631/**
 632 * v9fs_vfs_create - VFS hook to create a regular file
 633 * @idmap: idmap of the mount
 634 * @dir: The parent directory
 635 * @dentry: The name of file to be created
 636 * @mode: The UNIX file mode to set
 637 * @excl: True if the file must not yet exist
 638 *
 639 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 640 * for mknod(2).
 641 *
 642 */
 643
 644static int
 645v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
 646		struct dentry *dentry, umode_t mode, bool excl)
 647{
 648	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 649	u32 perm = unixmode2p9mode(v9ses, mode);
 650	struct p9_fid *fid;
 651
 652	/* P9_OEXCL? */
 653	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 654	if (IS_ERR(fid))
 655		return PTR_ERR(fid);
 656
 657	v9fs_invalidate_inode_attr(dir);
 658	p9_fid_put(fid);
 659
 660	return 0;
 661}
 662
 663/**
 664 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 665 * @idmap: idmap of the mount
 666 * @dir:  inode that is being unlinked
 667 * @dentry: dentry that is being unlinked
 668 * @mode: mode for new directory
 669 *
 670 */
 671
 672static struct dentry *v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 673				     struct dentry *dentry, umode_t mode)
 674{
 675	int err;
 676	u32 perm;
 677	struct p9_fid *fid;
 678	struct v9fs_session_info *v9ses;
 679
 680	p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 681	err = 0;
 682	v9ses = v9fs_inode2v9ses(dir);
 683	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 684	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 685	if (IS_ERR(fid)) {
 686		err = PTR_ERR(fid);
 687		fid = NULL;
 688	} else {
 689		inc_nlink(dir);
 690		v9fs_invalidate_inode_attr(dir);
 691	}
 692
 693	if (fid)
 694		p9_fid_put(fid);
 695	return ERR_PTR(err);
 696}
 697
 698/**
 699 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 700 * @dir:  inode that is being walked from
 701 * @dentry: dentry that is being walked to?
 702 * @flags: lookup flags (unused)
 703 *
 704 */
 705
 706struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 707				      unsigned int flags)
 708{
 709	struct dentry *res;
 710	struct v9fs_session_info *v9ses;
 711	struct p9_fid *dfid, *fid;
 712	struct inode *inode;
 713	const unsigned char *name;
 714
 715	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
 716		 dir, dentry, dentry, flags);
 717
 718	if (dentry->d_name.len > NAME_MAX)
 719		return ERR_PTR(-ENAMETOOLONG);
 720
 721	v9ses = v9fs_inode2v9ses(dir);
 722	/* We can walk d_parent because we hold the dir->i_mutex */
 723	dfid = v9fs_parent_fid(dentry);
 724	if (IS_ERR(dfid))
 725		return ERR_CAST(dfid);
 726
 727	/*
 728	 * Make sure we don't use a wrong inode due to parallel
 729	 * unlink. For cached mode create calls request for new
 730	 * inode. But with cache disabled, lookup should do this.
 731	 */
 732	name = dentry->d_name.name;
 733	fid = p9_client_walk(dfid, 1, &name, 1);
 734	p9_fid_put(dfid);
 735	if (fid == ERR_PTR(-ENOENT))
 736		inode = NULL;
 737	else if (IS_ERR(fid))
 738		inode = ERR_CAST(fid);
 739	else if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
 740		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 741	else
 742		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 743	/*
 744	 * If we had a rename on the server and a parallel lookup
 745	 * for the new name, then make sure we instantiate with
 746	 * the new name. ie look up for a/b, while on server somebody
 747	 * moved b under k and client parallely did a lookup for
 748	 * k/b.
 749	 */
 750	res = d_splice_alias(inode, dentry);
 751	if (!IS_ERR(fid)) {
 752		if (!res)
 753			v9fs_fid_add(dentry, &fid);
 754		else if (!IS_ERR(res))
 755			v9fs_fid_add(res, &fid);
 756		else
 757			p9_fid_put(fid);
 758	}
 759	return res;
 760}
 761
 762static int
 763v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 764		     struct file *file, unsigned int flags, umode_t mode)
 765{
 766	int err;
 767	u32 perm;
 768	struct v9fs_inode __maybe_unused *v9inode;
 769	struct v9fs_session_info *v9ses;
 770	struct p9_fid *fid;
 771	struct inode *inode;
 772	int p9_omode;
 773
 774	if (d_in_lookup(dentry)) {
 775		struct dentry *res = v9fs_vfs_lookup(dir, dentry, 0);
 776		if (res || d_really_is_positive(dentry))
 777			return finish_no_open(file, res);
 778	}
 779
 780	/* Only creates */
 781	if (!(flags & O_CREAT))
 782		return finish_no_open(file, NULL);
 783
 784	v9ses = v9fs_inode2v9ses(dir);
 785	perm = unixmode2p9mode(v9ses, mode);
 786	p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
 787
 788	if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
 789		p9_omode = (p9_omode & ~(P9_OWRITE | P9_OAPPEND)) | P9_ORDWR;
 790		p9_debug(P9_DEBUG_CACHE,
 791			"write-only file with writeback enabled, creating w/ O_RDWR\n");
 792	}
 793	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode);
 794	if (IS_ERR(fid))
 795		return PTR_ERR(fid);
 796
 797	v9fs_invalidate_inode_attr(dir);
 798	inode = d_inode(dentry);
 799	v9inode = V9FS_I(inode);
 800	err = finish_open(file, dentry, generic_file_open);
 801	if (unlikely(err)) {
 802		p9_fid_put(fid);
 803		return err;
 804	}
 805
 806	file->private_data = fid;
 807#ifdef CONFIG_9P_FSCACHE
 808	if (v9ses->cache & CACHE_FSCACHE)
 809		fscache_use_cookie(v9fs_inode_cookie(v9inode),
 810				   file->f_mode & FMODE_WRITE);
 811#endif
 812
 813	v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
 814	v9fs_open_fid_add(inode, &fid);
 815
 816	file->f_mode |= FMODE_CREATED;
 817	return 0;
 818}
 819
 820/**
 821 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 822 * @i:  inode that is being unlinked
 823 * @d: dentry that is being unlinked
 824 *
 825 */
 826
 827int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 828{
 829	return v9fs_remove(i, d, 0);
 830}
 831
 832/**
 833 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 834 * @i:  inode that is being unlinked
 835 * @d: dentry that is being unlinked
 836 *
 837 */
 838
 839int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 840{
 841	return v9fs_remove(i, d, AT_REMOVEDIR);
 842}
 843
 844/**
 845 * v9fs_vfs_rename - VFS hook to rename an inode
 846 * @idmap: The idmap of the mount
 847 * @old_dir:  old dir inode
 848 * @old_dentry: old dentry
 849 * @new_dir: new dir inode
 850 * @new_dentry: new dentry
 851 * @flags: RENAME_* flags
 852 *
 853 */
 854
 855int
 856v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 857		struct dentry *old_dentry, struct inode *new_dir,
 858		struct dentry *new_dentry, unsigned int flags)
 859{
 860	int retval;
 861	struct inode *old_inode;
 862	struct inode *new_inode;
 863	struct v9fs_session_info *v9ses;
 864	struct p9_fid *oldfid = NULL, *dfid = NULL;
 865	struct p9_fid *olddirfid = NULL;
 866	struct p9_fid *newdirfid = NULL;
 867	struct p9_wstat wstat;
 868
 869	if (flags)
 870		return -EINVAL;
 871
 872	p9_debug(P9_DEBUG_VFS, "\n");
 873	old_inode = d_inode(old_dentry);
 874	new_inode = d_inode(new_dentry);
 875	v9ses = v9fs_inode2v9ses(old_inode);
 876	oldfid = v9fs_fid_lookup(old_dentry);
 877	if (IS_ERR(oldfid))
 878		return PTR_ERR(oldfid);
 879
 880	dfid = v9fs_parent_fid(old_dentry);
 881	olddirfid = clone_fid(dfid);
 882	p9_fid_put(dfid);
 883	dfid = NULL;
 884
 885	if (IS_ERR(olddirfid)) {
 886		retval = PTR_ERR(olddirfid);
 887		goto error;
 888	}
 889
 890	dfid = v9fs_parent_fid(new_dentry);
 891	newdirfid = clone_fid(dfid);
 892	p9_fid_put(dfid);
 893	dfid = NULL;
 894
 895	if (IS_ERR(newdirfid)) {
 896		retval = PTR_ERR(newdirfid);
 897		goto error;
 898	}
 899
 900	down_write(&v9ses->rename_sem);
 901	if (v9fs_proto_dotl(v9ses)) {
 902		retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 903					    newdirfid, new_dentry->d_name.name);
 904		if (retval == -EOPNOTSUPP)
 905			retval = p9_client_rename(oldfid, newdirfid,
 906						  new_dentry->d_name.name);
 907		if (retval != -EOPNOTSUPP)
 908			goto error_locked;
 909	}
 910	if (old_dentry->d_parent != new_dentry->d_parent) {
 911		/*
 912		 * 9P .u can only handle file rename in the same directory
 913		 */
 914
 915		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 916		retval = -EXDEV;
 917		goto error_locked;
 918	}
 919	v9fs_blank_wstat(&wstat);
 920	wstat.muid = v9ses->uname;
 921	wstat.name = new_dentry->d_name.name;
 922	retval = p9_client_wstat(oldfid, &wstat);
 923
 924error_locked:
 925	if (!retval) {
 926		if (new_inode) {
 927			if (S_ISDIR(new_inode->i_mode))
 928				clear_nlink(new_inode);
 929			else
 930				v9fs_dec_count(new_inode);
 931		}
 932		if (S_ISDIR(old_inode->i_mode)) {
 933			if (!new_inode)
 934				inc_nlink(new_dir);
 935			v9fs_dec_count(old_dir);
 936		}
 937		v9fs_invalidate_inode_attr(old_inode);
 938		v9fs_invalidate_inode_attr(old_dir);
 939		v9fs_invalidate_inode_attr(new_dir);
 940
 941		/* successful rename */
 942		d_move(old_dentry, new_dentry);
 943	}
 944	up_write(&v9ses->rename_sem);
 945
 946error:
 947	p9_fid_put(newdirfid);
 948	p9_fid_put(olddirfid);
 949	p9_fid_put(oldfid);
 950	return retval;
 951}
 952
 953/**
 954 * v9fs_vfs_getattr - retrieve file metadata
 955 * @idmap: idmap of the mount
 956 * @path: Object to query
 957 * @stat: metadata structure to populate
 958 * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
 959 * @flags: AT_STATX_xxx setting
 960 *
 961 */
 962
 963static int
 964v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 965		 struct kstat *stat, u32 request_mask, unsigned int flags)
 966{
 967	struct dentry *dentry = path->dentry;
 968	struct inode *inode = d_inode(dentry);
 969	struct v9fs_session_info *v9ses;
 970	struct p9_fid *fid;
 971	struct p9_wstat *st;
 972
 973	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 974	v9ses = v9fs_dentry2v9ses(dentry);
 975	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
 976		generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
 977		return 0;
 978	} else if (v9ses->cache & CACHE_WRITEBACK) {
 979		if (S_ISREG(inode->i_mode)) {
 980			int retval = filemap_fdatawrite(inode->i_mapping);
 981
 982			if (retval)
 983				p9_debug(P9_DEBUG_ERROR,
 984				    "flushing writeback during getattr returned %d\n", retval);
 985		}
 986	}
 987	fid = v9fs_fid_lookup(dentry);
 988	if (IS_ERR(fid))
 989		return PTR_ERR(fid);
 990
 991	st = p9_client_stat(fid);
 992	p9_fid_put(fid);
 993	if (IS_ERR(st))
 994		return PTR_ERR(st);
 995
 996	v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
 997	generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
 998
 999	p9stat_free(st);
1000	kfree(st);
1001	return 0;
1002}
1003
1004/**
1005 * v9fs_vfs_setattr - set file metadata
1006 * @idmap: idmap of the mount
1007 * @dentry: file whose metadata to set
1008 * @iattr: metadata assignment structure
1009 *
1010 */
1011
1012static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
1013			    struct dentry *dentry, struct iattr *iattr)
1014{
1015	int retval, use_dentry = 0;
1016	struct inode *inode = d_inode(dentry);
1017	struct v9fs_session_info *v9ses;
1018	struct p9_fid *fid = NULL;
1019	struct p9_wstat wstat;
1020
1021	p9_debug(P9_DEBUG_VFS, "\n");
1022	retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
1023	if (retval)
1024		return retval;
1025
1026	v9ses = v9fs_dentry2v9ses(dentry);
1027	if (iattr->ia_valid & ATTR_FILE) {
1028		fid = iattr->ia_file->private_data;
1029		WARN_ON(!fid);
1030	}
1031	if (!fid) {
1032		fid = v9fs_fid_lookup(dentry);
1033		use_dentry = 1;
1034	}
1035	if (IS_ERR(fid))
1036		return PTR_ERR(fid);
1037
1038	v9fs_blank_wstat(&wstat);
1039	if (iattr->ia_valid & ATTR_MODE)
1040		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1041
1042	if (iattr->ia_valid & ATTR_MTIME)
1043		wstat.mtime = iattr->ia_mtime.tv_sec;
1044
1045	if (iattr->ia_valid & ATTR_ATIME)
1046		wstat.atime = iattr->ia_atime.tv_sec;
1047
1048	if (iattr->ia_valid & ATTR_SIZE)
1049		wstat.length = iattr->ia_size;
1050
1051	if (v9fs_proto_dotu(v9ses)) {
1052		if (iattr->ia_valid & ATTR_UID)
1053			wstat.n_uid = iattr->ia_uid;
1054
1055		if (iattr->ia_valid & ATTR_GID)
1056			wstat.n_gid = iattr->ia_gid;
1057	}
1058
1059	/* Write all dirty data */
1060	if (d_is_reg(dentry)) {
1061		retval = filemap_fdatawrite(inode->i_mapping);
1062		if (retval)
1063			p9_debug(P9_DEBUG_ERROR,
1064			    "flushing writeback during setattr returned %d\n", retval);
1065	}
1066
1067	retval = p9_client_wstat(fid, &wstat);
1068
1069	if (use_dentry)
1070		p9_fid_put(fid);
1071
1072	if (retval < 0)
1073		return retval;
1074
1075	if ((iattr->ia_valid & ATTR_SIZE) &&
1076		 iattr->ia_size != i_size_read(inode)) {
1077		truncate_setsize(inode, iattr->ia_size);
1078		netfs_resize_file(netfs_inode(inode), iattr->ia_size, true);
1079
1080#ifdef CONFIG_9P_FSCACHE
1081		if (v9ses->cache & CACHE_FSCACHE) {
1082			struct v9fs_inode *v9inode = V9FS_I(inode);
1083
1084			fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1085		}
1086#endif
1087	}
1088
1089	v9fs_invalidate_inode_attr(inode);
1090
1091	setattr_copy(&nop_mnt_idmap, inode, iattr);
1092	mark_inode_dirty(inode);
1093	return 0;
1094}
1095
1096/**
1097 * v9fs_stat2inode - populate an inode structure with mistat info
1098 * @stat: Plan 9 metadata (mistat) structure
1099 * @inode: inode to populate
1100 * @sb: superblock of filesystem
1101 * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1102 *
1103 */
1104
1105void
1106v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1107		 struct super_block *sb, unsigned int flags)
1108{
1109	umode_t mode;
1110	struct v9fs_session_info *v9ses = sb->s_fs_info;
1111	struct v9fs_inode *v9inode = V9FS_I(inode);
1112
1113	inode_set_atime(inode, stat->atime, 0);
1114	inode_set_mtime(inode, stat->mtime, 0);
1115	inode_set_ctime(inode, stat->mtime, 0);
1116
1117	inode->i_uid = v9ses->dfltuid;
1118	inode->i_gid = v9ses->dfltgid;
1119
1120	if (v9fs_proto_dotu(v9ses)) {
1121		inode->i_uid = stat->n_uid;
1122		inode->i_gid = stat->n_gid;
1123	}
1124	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1125		if (v9fs_proto_dotu(v9ses)) {
1126			unsigned int i_nlink;
1127			/*
1128			 * Hadlink support got added later to the .u extension.
1129			 * So there can be a server out there that doesn't
1130			 * support this even with .u extension. That would
1131			 * just leave us with stat->extension being an empty
1132			 * string, though.
1133			 */
1134			/* HARDLINKCOUNT %u */
1135			if (sscanf(stat->extension,
1136				   " HARDLINKCOUNT %u", &i_nlink) == 1)
1137				set_nlink(inode, i_nlink);
1138		}
1139	}
1140	mode = p9mode2perm(v9ses, stat);
1141	mode |= inode->i_mode & ~S_IALLUGO;
1142	inode->i_mode = mode;
1143
1144	v9inode->netfs.remote_i_size = stat->length;
1145	if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1146		v9fs_i_size_write(inode, stat->length);
1147	/* not real number of blocks, but 512 byte ones ... */
1148	inode->i_blocks = (stat->length + 512 - 1) >> 9;
1149	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1150}
1151
1152/**
1153 * v9fs_vfs_get_link - follow a symlink path
1154 * @dentry: dentry for symlink
1155 * @inode: inode for symlink
1156 * @done: delayed call for when we are done with the return value
1157 */
1158
1159static const char *v9fs_vfs_get_link(struct dentry *dentry,
1160				     struct inode *inode,
1161				     struct delayed_call *done)
1162{
1163	struct v9fs_session_info *v9ses;
1164	struct p9_fid *fid;
1165	struct p9_wstat *st;
1166	char *res;
1167
1168	if (!dentry)
1169		return ERR_PTR(-ECHILD);
1170
1171	v9ses = v9fs_dentry2v9ses(dentry);
1172	if (!v9fs_proto_dotu(v9ses))
1173		return ERR_PTR(-EBADF);
1174
1175	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1176	fid = v9fs_fid_lookup(dentry);
1177
1178	if (IS_ERR(fid))
1179		return ERR_CAST(fid);
1180
1181	st = p9_client_stat(fid);
1182	p9_fid_put(fid);
1183	if (IS_ERR(st))
1184		return ERR_CAST(st);
1185
1186	if (!(st->mode & P9_DMSYMLINK)) {
1187		p9stat_free(st);
1188		kfree(st);
1189		return ERR_PTR(-EINVAL);
1190	}
1191	res = st->extension;
1192	st->extension = NULL;
1193	if (strlen(res) >= PATH_MAX)
1194		res[PATH_MAX - 1] = '\0';
1195
1196	p9stat_free(st);
1197	kfree(st);
1198	set_delayed_call(done, kfree_link, res);
1199	return res;
1200}
1201
1202/**
1203 * v9fs_vfs_mkspecial - create a special file
1204 * @dir: inode to create special file in
1205 * @dentry: dentry to create
1206 * @perm: mode to create special file
1207 * @extension: 9p2000.u format extension string representing special file
1208 *
1209 */
1210
1211static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1212	u32 perm, const char *extension)
1213{
1214	struct p9_fid *fid;
1215	struct v9fs_session_info *v9ses;
1216
1217	v9ses = v9fs_inode2v9ses(dir);
1218	if (!v9fs_proto_dotu(v9ses)) {
1219		p9_debug(P9_DEBUG_ERROR, "not extended\n");
1220		return -EPERM;
1221	}
1222
1223	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1224								P9_OREAD);
1225	if (IS_ERR(fid))
1226		return PTR_ERR(fid);
1227
1228	v9fs_invalidate_inode_attr(dir);
1229	p9_fid_put(fid);
1230	return 0;
1231}
1232
1233/**
1234 * v9fs_vfs_symlink - helper function to create symlinks
1235 * @idmap: idmap of the mount
1236 * @dir: directory inode containing symlink
1237 * @dentry: dentry for symlink
1238 * @symname: symlink data
1239 *
1240 * See Also: 9P2000.u RFC for more information
1241 *
1242 */
1243
1244static int
1245v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1246		 struct dentry *dentry, const char *symname)
1247{
1248	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1249		 dir->i_ino, dentry, symname);
1250
1251	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1252}
1253
1254#define U32_MAX_DIGITS 10
1255
1256/**
1257 * v9fs_vfs_link - create a hardlink
1258 * @old_dentry: dentry for file to link to
1259 * @dir: inode destination for new link
1260 * @dentry: dentry for link
1261 *
1262 */
1263
1264static int
1265v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1266	      struct dentry *dentry)
1267{
1268	int retval;
1269	char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1270	struct p9_fid *oldfid;
1271
1272	p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1273		 dir->i_ino, dentry, old_dentry);
1274
1275	oldfid = v9fs_fid_clone(old_dentry);
1276	if (IS_ERR(oldfid))
1277		return PTR_ERR(oldfid);
1278
1279	sprintf(name, "%d\n", oldfid->fid);
1280	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1281	if (!retval) {
1282		v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1283		v9fs_invalidate_inode_attr(dir);
1284	}
1285	p9_fid_put(oldfid);
1286	return retval;
1287}
1288
1289/**
1290 * v9fs_vfs_mknod - create a special file
1291 * @idmap: idmap of the mount
1292 * @dir: inode destination for new link
1293 * @dentry: dentry for file
1294 * @mode: mode for creation
1295 * @rdev: device associated with special file
1296 *
1297 */
1298
1299static int
1300v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1301	       struct dentry *dentry, umode_t mode, dev_t rdev)
1302{
1303	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1304	int retval;
1305	char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1306	u32 perm;
1307
1308	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1309		 dir->i_ino, dentry, mode,
1310		 MAJOR(rdev), MINOR(rdev));
1311
1312	/* build extension */
1313	if (S_ISBLK(mode))
1314		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1315	else if (S_ISCHR(mode))
1316		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1317	else
1318		*name = 0;
1319
1320	perm = unixmode2p9mode(v9ses, mode);
1321	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1322
1323	return retval;
1324}
1325
1326int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1327{
1328	int umode;
1329	dev_t rdev;
1330	struct p9_wstat *st;
1331	struct v9fs_session_info *v9ses;
1332	unsigned int flags;
1333
1334	v9ses = v9fs_inode2v9ses(inode);
1335	st = p9_client_stat(fid);
1336	if (IS_ERR(st))
1337		return PTR_ERR(st);
1338	/*
1339	 * Don't update inode if the file type is different
1340	 */
1341	umode = p9mode2unixmode(v9ses, st, &rdev);
1342	if (inode_wrong_type(inode, umode))
1343		goto out;
1344
1345	/*
1346	 * We don't want to refresh inode->i_size,
1347	 * because we may have cached data
1348	 */
1349	flags = (v9ses->cache & CACHE_LOOSE) ?
1350		V9FS_STAT2INODE_KEEP_ISIZE : 0;
1351	v9fs_stat2inode(st, inode, inode->i_sb, flags);
1352out:
1353	p9stat_free(st);
1354	kfree(st);
1355	return 0;
1356}
1357
1358static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1359	.create = v9fs_vfs_create,
1360	.lookup = v9fs_vfs_lookup,
1361	.atomic_open = v9fs_vfs_atomic_open,
1362	.symlink = v9fs_vfs_symlink,
1363	.link = v9fs_vfs_link,
1364	.unlink = v9fs_vfs_unlink,
1365	.mkdir = v9fs_vfs_mkdir,
1366	.rmdir = v9fs_vfs_rmdir,
1367	.mknod = v9fs_vfs_mknod,
1368	.rename = v9fs_vfs_rename,
1369	.getattr = v9fs_vfs_getattr,
1370	.setattr = v9fs_vfs_setattr,
1371};
1372
1373static const struct inode_operations v9fs_dir_inode_operations = {
1374	.create = v9fs_vfs_create,
1375	.lookup = v9fs_vfs_lookup,
1376	.atomic_open = v9fs_vfs_atomic_open,
1377	.unlink = v9fs_vfs_unlink,
1378	.mkdir = v9fs_vfs_mkdir,
1379	.rmdir = v9fs_vfs_rmdir,
1380	.mknod = v9fs_vfs_mknod,
1381	.rename = v9fs_vfs_rename,
1382	.getattr = v9fs_vfs_getattr,
1383	.setattr = v9fs_vfs_setattr,
1384};
1385
1386static const struct inode_operations v9fs_file_inode_operations = {
1387	.getattr = v9fs_vfs_getattr,
1388	.setattr = v9fs_vfs_setattr,
1389};
1390
1391static const struct inode_operations v9fs_symlink_inode_operations = {
1392	.get_link = v9fs_vfs_get_link,
1393	.getattr = v9fs_vfs_getattr,
1394	.setattr = v9fs_vfs_setattr,
1395};