linux/fs/9p/vfs_inode.c
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   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 (extended) {
 196                if (uflags & O_EXCL)
 197                        ret |= P9_OEXCL;
 198
 199                if (uflags & O_APPEND)
 200                        ret |= P9_OAPPEND;
 201        }
 202
 203        return ret;
 204}
 205
 206/**
 207 * v9fs_blank_wstat - helper function to setup a 9P stat structure
 208 * @wstat: structure to initialize
 209 *
 210 */
 211
 212void
 213v9fs_blank_wstat(struct p9_wstat *wstat)
 214{
 215        wstat->type = ~0;
 216        wstat->dev = ~0;
 217        wstat->qid.type = ~0;
 218        wstat->qid.version = ~0;
 219        *((long long *)&wstat->qid.path) = ~0;
 220        wstat->mode = ~0;
 221        wstat->atime = ~0;
 222        wstat->mtime = ~0;
 223        wstat->length = ~0;
 224        wstat->name = NULL;
 225        wstat->uid = NULL;
 226        wstat->gid = NULL;
 227        wstat->muid = NULL;
 228        wstat->n_uid = INVALID_UID;
 229        wstat->n_gid = INVALID_GID;
 230        wstat->n_muid = INVALID_UID;
 231        wstat->extension = NULL;
 232}
 233
 234/**
 235 * v9fs_alloc_inode - helper function to allocate an inode
 236 *
 237 */
 238struct inode *v9fs_alloc_inode(struct super_block *sb)
 239{
 240        struct v9fs_inode *v9inode;
 241        v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 242                                                        GFP_KERNEL);
 243        if (!v9inode)
 244                return NULL;
 245#ifdef CONFIG_9P_FSCACHE
 246        v9inode->fscache = NULL;
 247        spin_lock_init(&v9inode->fscache_lock);
 248#endif
 249        v9inode->writeback_fid = NULL;
 250        v9inode->cache_validity = 0;
 251        mutex_init(&v9inode->v_mutex);
 252        return &v9inode->vfs_inode;
 253}
 254
 255/**
 256 * v9fs_destroy_inode - destroy an inode
 257 *
 258 */
 259
 260static void v9fs_i_callback(struct rcu_head *head)
 261{
 262        struct inode *inode = container_of(head, struct inode, i_rcu);
 263        kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 264}
 265
 266void v9fs_destroy_inode(struct inode *inode)
 267{
 268        call_rcu(&inode->i_rcu, v9fs_i_callback);
 269}
 270
 271int v9fs_init_inode(struct v9fs_session_info *v9ses,
 272                    struct inode *inode, umode_t mode, dev_t rdev)
 273{
 274        int err = 0;
 275
 276        inode_init_owner(inode, NULL, mode);
 277        inode->i_blocks = 0;
 278        inode->i_rdev = rdev;
 279        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 280        inode->i_mapping->a_ops = &v9fs_addr_operations;
 281
 282        switch (mode & S_IFMT) {
 283        case S_IFIFO:
 284        case S_IFBLK:
 285        case S_IFCHR:
 286        case S_IFSOCK:
 287                if (v9fs_proto_dotl(v9ses)) {
 288                        inode->i_op = &v9fs_file_inode_operations_dotl;
 289                } else if (v9fs_proto_dotu(v9ses)) {
 290                        inode->i_op = &v9fs_file_inode_operations;
 291                } else {
 292                        p9_debug(P9_DEBUG_ERROR,
 293                                 "special files without extended mode\n");
 294                        err = -EINVAL;
 295                        goto error;
 296                }
 297                init_special_inode(inode, inode->i_mode, inode->i_rdev);
 298                break;
 299        case S_IFREG:
 300                if (v9fs_proto_dotl(v9ses)) {
 301                        inode->i_op = &v9fs_file_inode_operations_dotl;
 302                        if (v9ses->cache)
 303                                inode->i_fop =
 304                                        &v9fs_cached_file_operations_dotl;
 305                        else
 306                                inode->i_fop = &v9fs_file_operations_dotl;
 307                } else {
 308                        inode->i_op = &v9fs_file_inode_operations;
 309                        if (v9ses->cache)
 310                                inode->i_fop = &v9fs_cached_file_operations;
 311                        else
 312                                inode->i_fop = &v9fs_file_operations;
 313                }
 314
 315                break;
 316        case S_IFLNK:
 317                if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 318                        p9_debug(P9_DEBUG_ERROR,
 319                                 "extended modes used with legacy protocol\n");
 320                        err = -EINVAL;
 321                        goto error;
 322                }
 323
 324                if (v9fs_proto_dotl(v9ses))
 325                        inode->i_op = &v9fs_symlink_inode_operations_dotl;
 326                else
 327                        inode->i_op = &v9fs_symlink_inode_operations;
 328
 329                break;
 330        case S_IFDIR:
 331                inc_nlink(inode);
 332                if (v9fs_proto_dotl(v9ses))
 333                        inode->i_op = &v9fs_dir_inode_operations_dotl;
 334                else if (v9fs_proto_dotu(v9ses))
 335                        inode->i_op = &v9fs_dir_inode_operations_dotu;
 336                else
 337                        inode->i_op = &v9fs_dir_inode_operations;
 338
 339                if (v9fs_proto_dotl(v9ses))
 340                        inode->i_fop = &v9fs_dir_operations_dotl;
 341                else
 342                        inode->i_fop = &v9fs_dir_operations;
 343
 344                break;
 345        default:
 346                p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 347                         mode, mode & S_IFMT);
 348                err = -EINVAL;
 349                goto error;
 350        }
 351error:
 352        return err;
 353
 354}
 355
 356/**
 357 * v9fs_get_inode - helper function to setup an inode
 358 * @sb: superblock
 359 * @mode: mode to setup inode with
 360 *
 361 */
 362
 363struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 364{
 365        int err;
 366        struct inode *inode;
 367        struct v9fs_session_info *v9ses = sb->s_fs_info;
 368
 369        p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 370
 371        inode = new_inode(sb);
 372        if (!inode) {
 373                pr_warn("%s (%d): Problem allocating inode\n",
 374                        __func__, task_pid_nr(current));
 375                return ERR_PTR(-ENOMEM);
 376        }
 377        err = v9fs_init_inode(v9ses, inode, mode, rdev);
 378        if (err) {
 379                iput(inode);
 380                return ERR_PTR(err);
 381        }
 382        return inode;
 383}
 384
 385/*
 386static struct v9fs_fid*
 387v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 388{
 389        int err;
 390        int nfid;
 391        struct v9fs_fid *ret;
 392        struct v9fs_fcall *fcall;
 393
 394        nfid = v9fs_get_idpool(&v9ses->fidpool);
 395        if (nfid < 0) {
 396                eprintk(KERN_WARNING, "no free fids available\n");
 397                return ERR_PTR(-ENOSPC);
 398        }
 399
 400        err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 401                &fcall);
 402
 403        if (err < 0) {
 404                if (fcall && fcall->id == RWALK)
 405                        goto clunk_fid;
 406
 407                PRINT_FCALL_ERROR("walk error", fcall);
 408                v9fs_put_idpool(nfid, &v9ses->fidpool);
 409                goto error;
 410        }
 411
 412        kfree(fcall);
 413        fcall = NULL;
 414        ret = v9fs_fid_create(v9ses, nfid);
 415        if (!ret) {
 416                err = -ENOMEM;
 417                goto clunk_fid;
 418        }
 419
 420        err = v9fs_fid_insert(ret, dentry);
 421        if (err < 0) {
 422                v9fs_fid_destroy(ret);
 423                goto clunk_fid;
 424        }
 425
 426        return ret;
 427
 428clunk_fid:
 429        v9fs_t_clunk(v9ses, nfid);
 430
 431error:
 432        kfree(fcall);
 433        return ERR_PTR(err);
 434}
 435*/
 436
 437
 438/**
 439 * v9fs_clear_inode - release an inode
 440 * @inode: inode to release
 441 *
 442 */
 443void v9fs_evict_inode(struct inode *inode)
 444{
 445        struct v9fs_inode *v9inode = V9FS_I(inode);
 446
 447        truncate_inode_pages(inode->i_mapping, 0);
 448        clear_inode(inode);
 449        filemap_fdatawrite(inode->i_mapping);
 450
 451#ifdef CONFIG_9P_FSCACHE
 452        v9fs_cache_inode_put_cookie(inode);
 453#endif
 454        /* clunk the fid stashed in writeback_fid */
 455        if (v9inode->writeback_fid) {
 456                p9_client_clunk(v9inode->writeback_fid);
 457                v9inode->writeback_fid = NULL;
 458        }
 459}
 460
 461static int v9fs_test_inode(struct inode *inode, void *data)
 462{
 463        int umode;
 464        dev_t rdev;
 465        struct v9fs_inode *v9inode = V9FS_I(inode);
 466        struct p9_wstat *st = (struct p9_wstat *)data;
 467        struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 468
 469        umode = p9mode2unixmode(v9ses, st, &rdev);
 470        /* don't match inode of different type */
 471        if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 472                return 0;
 473
 474        /* compare qid details */
 475        if (memcmp(&v9inode->qid.version,
 476                   &st->qid.version, sizeof(v9inode->qid.version)))
 477                return 0;
 478
 479        if (v9inode->qid.type != st->qid.type)
 480                return 0;
 481        return 1;
 482}
 483
 484static int v9fs_test_new_inode(struct inode *inode, void *data)
 485{
 486        return 0;
 487}
 488
 489static int v9fs_set_inode(struct inode *inode,  void *data)
 490{
 491        struct v9fs_inode *v9inode = V9FS_I(inode);
 492        struct p9_wstat *st = (struct p9_wstat *)data;
 493
 494        memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 495        return 0;
 496}
 497
 498static struct inode *v9fs_qid_iget(struct super_block *sb,
 499                                   struct p9_qid *qid,
 500                                   struct p9_wstat *st,
 501                                   int new)
 502{
 503        dev_t rdev;
 504        int retval;
 505        umode_t umode;
 506        unsigned long i_ino;
 507        struct inode *inode;
 508        struct v9fs_session_info *v9ses = sb->s_fs_info;
 509        int (*test)(struct inode *, void *);
 510
 511        if (new)
 512                test = v9fs_test_new_inode;
 513        else
 514                test = v9fs_test_inode;
 515
 516        i_ino = v9fs_qid2ino(qid);
 517        inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 518        if (!inode)
 519                return ERR_PTR(-ENOMEM);
 520        if (!(inode->i_state & I_NEW))
 521                return inode;
 522        /*
 523         * initialize the inode with the stat info
 524         * FIXME!! we may need support for stale inodes
 525         * later.
 526         */
 527        inode->i_ino = i_ino;
 528        umode = p9mode2unixmode(v9ses, st, &rdev);
 529        retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 530        if (retval)
 531                goto error;
 532
 533        v9fs_stat2inode(st, inode, sb);
 534#ifdef CONFIG_9P_FSCACHE
 535        v9fs_cache_inode_get_cookie(inode);
 536#endif
 537        unlock_new_inode(inode);
 538        return inode;
 539error:
 540        unlock_new_inode(inode);
 541        iput(inode);
 542        return ERR_PTR(retval);
 543
 544}
 545
 546struct inode *
 547v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 548                    struct super_block *sb, int new)
 549{
 550        struct p9_wstat *st;
 551        struct inode *inode = NULL;
 552
 553        st = p9_client_stat(fid);
 554        if (IS_ERR(st))
 555                return ERR_CAST(st);
 556
 557        inode = v9fs_qid_iget(sb, &st->qid, st, new);
 558        p9stat_free(st);
 559        kfree(st);
 560        return inode;
 561}
 562
 563/**
 564 * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 565 * plan 9 AT flag.
 566 * @flags: flags to convert
 567 */
 568static int v9fs_at_to_dotl_flags(int flags)
 569{
 570        int rflags = 0;
 571        if (flags & AT_REMOVEDIR)
 572                rflags |= P9_DOTL_AT_REMOVEDIR;
 573        return rflags;
 574}
 575
 576/**
 577 * v9fs_remove - helper function to remove files and directories
 578 * @dir: directory inode that is being deleted
 579 * @dentry:  dentry that is being deleted
 580 * @rmdir: removing a directory
 581 *
 582 */
 583
 584static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 585{
 586        struct inode *inode;
 587        int retval = -EOPNOTSUPP;
 588        struct p9_fid *v9fid, *dfid;
 589        struct v9fs_session_info *v9ses;
 590
 591        p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 592                 dir, dentry, flags);
 593
 594        v9ses = v9fs_inode2v9ses(dir);
 595        inode = dentry->d_inode;
 596        dfid = v9fs_fid_lookup(dentry->d_parent);
 597        if (IS_ERR(dfid)) {
 598                retval = PTR_ERR(dfid);
 599                p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 600                return retval;
 601        }
 602        if (v9fs_proto_dotl(v9ses))
 603                retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 604                                            v9fs_at_to_dotl_flags(flags));
 605        if (retval == -EOPNOTSUPP) {
 606                /* Try the one based on path */
 607                v9fid = v9fs_fid_clone(dentry);
 608                if (IS_ERR(v9fid))
 609                        return PTR_ERR(v9fid);
 610                retval = p9_client_remove(v9fid);
 611        }
 612        if (!retval) {
 613                /*
 614                 * directories on unlink should have zero
 615                 * link count
 616                 */
 617                if (flags & AT_REMOVEDIR) {
 618                        clear_nlink(inode);
 619                        drop_nlink(dir);
 620                } else
 621                        drop_nlink(inode);
 622
 623                v9fs_invalidate_inode_attr(inode);
 624                v9fs_invalidate_inode_attr(dir);
 625        }
 626        return retval;
 627}
 628
 629/**
 630 * v9fs_create - Create a file
 631 * @v9ses: session information
 632 * @dir: directory that dentry is being created in
 633 * @dentry:  dentry that is being created
 634 * @extension: 9p2000.u extension string to support devices, etc.
 635 * @perm: create permissions
 636 * @mode: open mode
 637 *
 638 */
 639static struct p9_fid *
 640v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 641                struct dentry *dentry, char *extension, u32 perm, u8 mode)
 642{
 643        int err;
 644        char *name;
 645        struct p9_fid *dfid, *ofid, *fid;
 646        struct inode *inode;
 647
 648        p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 649
 650        err = 0;
 651        ofid = NULL;
 652        fid = NULL;
 653        name = (char *) dentry->d_name.name;
 654        dfid = v9fs_fid_lookup(dentry->d_parent);
 655        if (IS_ERR(dfid)) {
 656                err = PTR_ERR(dfid);
 657                p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 658                return ERR_PTR(err);
 659        }
 660
 661        /* clone a fid to use for creation */
 662        ofid = p9_client_walk(dfid, 0, NULL, 1);
 663        if (IS_ERR(ofid)) {
 664                err = PTR_ERR(ofid);
 665                p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 666                return ERR_PTR(err);
 667        }
 668
 669        err = p9_client_fcreate(ofid, name, perm, mode, extension);
 670        if (err < 0) {
 671                p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 672                goto error;
 673        }
 674
 675        if (!(perm & P9_DMLINK)) {
 676                /* now walk from the parent so we can get unopened fid */
 677                fid = p9_client_walk(dfid, 1, &name, 1);
 678                if (IS_ERR(fid)) {
 679                        err = PTR_ERR(fid);
 680                        p9_debug(P9_DEBUG_VFS,
 681                                   "p9_client_walk failed %d\n", err);
 682                        fid = NULL;
 683                        goto error;
 684                }
 685                /*
 686                 * instantiate inode and assign the unopened fid to the dentry
 687                 */
 688                inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 689                if (IS_ERR(inode)) {
 690                        err = PTR_ERR(inode);
 691                        p9_debug(P9_DEBUG_VFS,
 692                                   "inode creation failed %d\n", err);
 693                        goto error;
 694                }
 695                v9fs_fid_add(dentry, fid);
 696                d_instantiate(dentry, inode);
 697        }
 698        return ofid;
 699error:
 700        if (ofid)
 701                p9_client_clunk(ofid);
 702
 703        if (fid)
 704                p9_client_clunk(fid);
 705
 706        return ERR_PTR(err);
 707}
 708
 709/**
 710 * v9fs_vfs_create - VFS hook to create a regular file
 711 *
 712 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 713 * for mknod(2).
 714 *
 715 * @dir: directory inode that is being created
 716 * @dentry:  dentry that is being deleted
 717 * @mode: create permissions
 718 *
 719 */
 720
 721static int
 722v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 723                bool excl)
 724{
 725        struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 726        u32 perm = unixmode2p9mode(v9ses, mode);
 727        struct p9_fid *fid;
 728
 729        /* P9_OEXCL? */
 730        fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 731        if (IS_ERR(fid))
 732                return PTR_ERR(fid);
 733
 734        v9fs_invalidate_inode_attr(dir);
 735        p9_client_clunk(fid);
 736
 737        return 0;
 738}
 739
 740/**
 741 * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 742 * @dir:  inode that is being unlinked
 743 * @dentry: dentry that is being unlinked
 744 * @mode: mode for new directory
 745 *
 746 */
 747
 748static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 749{
 750        int err;
 751        u32 perm;
 752        struct p9_fid *fid;
 753        struct v9fs_session_info *v9ses;
 754
 755        p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 756        err = 0;
 757        v9ses = v9fs_inode2v9ses(dir);
 758        perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 759        fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 760        if (IS_ERR(fid)) {
 761                err = PTR_ERR(fid);
 762                fid = NULL;
 763        } else {
 764                inc_nlink(dir);
 765                v9fs_invalidate_inode_attr(dir);
 766        }
 767
 768        if (fid)
 769                p9_client_clunk(fid);
 770
 771        return err;
 772}
 773
 774/**
 775 * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 776 * @dir:  inode that is being walked from
 777 * @dentry: dentry that is being walked to?
 778 * @nameidata: path data
 779 *
 780 */
 781
 782struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 783                                      unsigned int flags)
 784{
 785        struct dentry *res;
 786        struct super_block *sb;
 787        struct v9fs_session_info *v9ses;
 788        struct p9_fid *dfid, *fid;
 789        struct inode *inode;
 790        char *name;
 791
 792        p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p flags: %x\n",
 793                 dir, dentry->d_name.name, dentry, flags);
 794
 795        if (dentry->d_name.len > NAME_MAX)
 796                return ERR_PTR(-ENAMETOOLONG);
 797
 798        sb = dir->i_sb;
 799        v9ses = v9fs_inode2v9ses(dir);
 800        /* We can walk d_parent because we hold the dir->i_mutex */
 801        dfid = v9fs_fid_lookup(dentry->d_parent);
 802        if (IS_ERR(dfid))
 803                return ERR_CAST(dfid);
 804
 805        name = (char *) dentry->d_name.name;
 806        fid = p9_client_walk(dfid, 1, &name, 1);
 807        if (IS_ERR(fid)) {
 808                if (fid == ERR_PTR(-ENOENT)) {
 809                        d_add(dentry, NULL);
 810                        return NULL;
 811                }
 812                return ERR_CAST(fid);
 813        }
 814        /*
 815         * Make sure we don't use a wrong inode due to parallel
 816         * unlink. For cached mode create calls request for new
 817         * inode. But with cache disabled, lookup should do this.
 818         */
 819        if (v9ses->cache)
 820                inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 821        else
 822                inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 823        if (IS_ERR(inode)) {
 824                p9_client_clunk(fid);
 825                return ERR_CAST(inode);
 826        }
 827        /*
 828         * If we had a rename on the server and a parallel lookup
 829         * for the new name, then make sure we instantiate with
 830         * the new name. ie look up for a/b, while on server somebody
 831         * moved b under k and client parallely did a lookup for
 832         * k/b.
 833         */
 834        res = d_materialise_unique(dentry, inode);
 835        if (!res)
 836                v9fs_fid_add(dentry, fid);
 837        else if (!IS_ERR(res))
 838                v9fs_fid_add(res, fid);
 839        else
 840                p9_client_clunk(fid);
 841        return res;
 842}
 843
 844static int
 845v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 846                     struct file *file, unsigned flags, umode_t mode,
 847                     int *opened)
 848{
 849        int err;
 850        u32 perm;
 851        struct v9fs_inode *v9inode;
 852        struct v9fs_session_info *v9ses;
 853        struct p9_fid *fid, *inode_fid;
 854        struct dentry *res = NULL;
 855
 856        if (d_unhashed(dentry)) {
 857                res = v9fs_vfs_lookup(dir, dentry, 0);
 858                if (IS_ERR(res))
 859                        return PTR_ERR(res);
 860
 861                if (res)
 862                        dentry = res;
 863        }
 864
 865        /* Only creates */
 866        if (!(flags & O_CREAT) || dentry->d_inode)
 867                return finish_no_open(file, res);
 868
 869        err = 0;
 870        fid = NULL;
 871        v9ses = v9fs_inode2v9ses(dir);
 872        perm = unixmode2p9mode(v9ses, mode);
 873        fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 874                                v9fs_uflags2omode(flags,
 875                                                v9fs_proto_dotu(v9ses)));
 876        if (IS_ERR(fid)) {
 877                err = PTR_ERR(fid);
 878                fid = NULL;
 879                goto error;
 880        }
 881
 882        v9fs_invalidate_inode_attr(dir);
 883        v9inode = V9FS_I(dentry->d_inode);
 884        mutex_lock(&v9inode->v_mutex);
 885        if (v9ses->cache && !v9inode->writeback_fid &&
 886            ((flags & O_ACCMODE) != O_RDONLY)) {
 887                /*
 888                 * clone a fid and add it to writeback_fid
 889                 * we do it during open time instead of
 890                 * page dirty time via write_begin/page_mkwrite
 891                 * because we want write after unlink usecase
 892                 * to work.
 893                 */
 894                inode_fid = v9fs_writeback_fid(dentry);
 895                if (IS_ERR(inode_fid)) {
 896                        err = PTR_ERR(inode_fid);
 897                        mutex_unlock(&v9inode->v_mutex);
 898                        goto error;
 899                }
 900                v9inode->writeback_fid = (void *) inode_fid;
 901        }
 902        mutex_unlock(&v9inode->v_mutex);
 903        err = finish_open(file, dentry, generic_file_open, opened);
 904        if (err)
 905                goto error;
 906
 907        file->private_data = fid;
 908#ifdef CONFIG_9P_FSCACHE
 909        if (v9ses->cache)
 910                v9fs_cache_inode_set_cookie(dentry->d_inode, file);
 911#endif
 912
 913        *opened |= FILE_CREATED;
 914out:
 915        dput(res);
 916        return err;
 917
 918error:
 919        if (fid)
 920                p9_client_clunk(fid);
 921        goto out;
 922}
 923
 924/**
 925 * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 926 * @i:  inode that is being unlinked
 927 * @d: dentry that is being unlinked
 928 *
 929 */
 930
 931int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 932{
 933        return v9fs_remove(i, d, 0);
 934}
 935
 936/**
 937 * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 938 * @i:  inode that is being unlinked
 939 * @d: dentry that is being unlinked
 940 *
 941 */
 942
 943int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 944{
 945        return v9fs_remove(i, d, AT_REMOVEDIR);
 946}
 947
 948/**
 949 * v9fs_vfs_rename - VFS hook to rename an inode
 950 * @old_dir:  old dir inode
 951 * @old_dentry: old dentry
 952 * @new_dir: new dir inode
 953 * @new_dentry: new dentry
 954 *
 955 */
 956
 957int
 958v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 959                struct inode *new_dir, struct dentry *new_dentry)
 960{
 961        int retval;
 962        struct inode *old_inode;
 963        struct inode *new_inode;
 964        struct v9fs_session_info *v9ses;
 965        struct p9_fid *oldfid;
 966        struct p9_fid *olddirfid;
 967        struct p9_fid *newdirfid;
 968        struct p9_wstat wstat;
 969
 970        p9_debug(P9_DEBUG_VFS, "\n");
 971        retval = 0;
 972        old_inode = old_dentry->d_inode;
 973        new_inode = new_dentry->d_inode;
 974        v9ses = v9fs_inode2v9ses(old_inode);
 975        oldfid = v9fs_fid_lookup(old_dentry);
 976        if (IS_ERR(oldfid))
 977                return PTR_ERR(oldfid);
 978
 979        olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 980        if (IS_ERR(olddirfid)) {
 981                retval = PTR_ERR(olddirfid);
 982                goto done;
 983        }
 984
 985        newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 986        if (IS_ERR(newdirfid)) {
 987                retval = PTR_ERR(newdirfid);
 988                goto clunk_olddir;
 989        }
 990
 991        down_write(&v9ses->rename_sem);
 992        if (v9fs_proto_dotl(v9ses)) {
 993                retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 994                                            newdirfid, new_dentry->d_name.name);
 995                if (retval == -EOPNOTSUPP)
 996                        retval = p9_client_rename(oldfid, newdirfid,
 997                                                  new_dentry->d_name.name);
 998                if (retval != -EOPNOTSUPP)
 999                        goto clunk_newdir;
1000        }
1001        if (old_dentry->d_parent != new_dentry->d_parent) {
1002                /*
1003                 * 9P .u can only handle file rename in the same directory
1004                 */
1005
1006                p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1007                retval = -EXDEV;
1008                goto clunk_newdir;
1009        }
1010        v9fs_blank_wstat(&wstat);
1011        wstat.muid = v9ses->uname;
1012        wstat.name = (char *) new_dentry->d_name.name;
1013        retval = p9_client_wstat(oldfid, &wstat);
1014
1015clunk_newdir:
1016        if (!retval) {
1017                if (new_inode) {
1018                        if (S_ISDIR(new_inode->i_mode))
1019                                clear_nlink(new_inode);
1020                        else
1021                                drop_nlink(new_inode);
1022                }
1023                if (S_ISDIR(old_inode->i_mode)) {
1024                        if (!new_inode)
1025                                inc_nlink(new_dir);
1026                        drop_nlink(old_dir);
1027                }
1028                v9fs_invalidate_inode_attr(old_inode);
1029                v9fs_invalidate_inode_attr(old_dir);
1030                v9fs_invalidate_inode_attr(new_dir);
1031
1032                /* successful rename */
1033                d_move(old_dentry, new_dentry);
1034        }
1035        up_write(&v9ses->rename_sem);
1036        p9_client_clunk(newdirfid);
1037
1038clunk_olddir:
1039        p9_client_clunk(olddirfid);
1040
1041done:
1042        return retval;
1043}
1044
1045/**
1046 * v9fs_vfs_getattr - retrieve file metadata
1047 * @mnt: mount information
1048 * @dentry: file to get attributes on
1049 * @stat: metadata structure to populate
1050 *
1051 */
1052
1053static int
1054v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1055                 struct kstat *stat)
1056{
1057        struct v9fs_session_info *v9ses;
1058        struct p9_fid *fid;
1059        struct p9_wstat *st;
1060
1061        p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1062        v9ses = v9fs_dentry2v9ses(dentry);
1063        if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1064                generic_fillattr(dentry->d_inode, stat);
1065                return 0;
1066        }
1067        fid = v9fs_fid_lookup(dentry);
1068        if (IS_ERR(fid))
1069                return PTR_ERR(fid);
1070
1071        st = p9_client_stat(fid);
1072        if (IS_ERR(st))
1073                return PTR_ERR(st);
1074
1075        v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1076        generic_fillattr(dentry->d_inode, stat);
1077
1078        p9stat_free(st);
1079        kfree(st);
1080        return 0;
1081}
1082
1083/**
1084 * v9fs_vfs_setattr - set file metadata
1085 * @dentry: file whose metadata to set
1086 * @iattr: metadata assignment structure
1087 *
1088 */
1089
1090static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1091{
1092        int retval;
1093        struct v9fs_session_info *v9ses;
1094        struct p9_fid *fid;
1095        struct p9_wstat wstat;
1096
1097        p9_debug(P9_DEBUG_VFS, "\n");
1098        retval = inode_change_ok(dentry->d_inode, iattr);
1099        if (retval)
1100                return retval;
1101
1102        retval = -EPERM;
1103        v9ses = v9fs_dentry2v9ses(dentry);
1104        fid = v9fs_fid_lookup(dentry);
1105        if(IS_ERR(fid))
1106                return PTR_ERR(fid);
1107
1108        v9fs_blank_wstat(&wstat);
1109        if (iattr->ia_valid & ATTR_MODE)
1110                wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1111
1112        if (iattr->ia_valid & ATTR_MTIME)
1113                wstat.mtime = iattr->ia_mtime.tv_sec;
1114
1115        if (iattr->ia_valid & ATTR_ATIME)
1116                wstat.atime = iattr->ia_atime.tv_sec;
1117
1118        if (iattr->ia_valid & ATTR_SIZE)
1119                wstat.length = iattr->ia_size;
1120
1121        if (v9fs_proto_dotu(v9ses)) {
1122                if (iattr->ia_valid & ATTR_UID)
1123                        wstat.n_uid = iattr->ia_uid;
1124
1125                if (iattr->ia_valid & ATTR_GID)
1126                        wstat.n_gid = iattr->ia_gid;
1127        }
1128
1129        /* Write all dirty data */
1130        if (S_ISREG(dentry->d_inode->i_mode))
1131                filemap_write_and_wait(dentry->d_inode->i_mapping);
1132
1133        retval = p9_client_wstat(fid, &wstat);
1134        if (retval < 0)
1135                return retval;
1136
1137        if ((iattr->ia_valid & ATTR_SIZE) &&
1138            iattr->ia_size != i_size_read(dentry->d_inode))
1139                truncate_setsize(dentry->d_inode, iattr->ia_size);
1140
1141        v9fs_invalidate_inode_attr(dentry->d_inode);
1142
1143        setattr_copy(dentry->d_inode, iattr);
1144        mark_inode_dirty(dentry->d_inode);
1145        return 0;
1146}
1147
1148/**
1149 * v9fs_stat2inode - populate an inode structure with mistat info
1150 * @stat: Plan 9 metadata (mistat) structure
1151 * @inode: inode to populate
1152 * @sb: superblock of filesystem
1153 *
1154 */
1155
1156void
1157v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1158        struct super_block *sb)
1159{
1160        umode_t mode;
1161        char ext[32];
1162        char tag_name[14];
1163        unsigned int i_nlink;
1164        struct v9fs_session_info *v9ses = sb->s_fs_info;
1165        struct v9fs_inode *v9inode = V9FS_I(inode);
1166
1167        set_nlink(inode, 1);
1168
1169        inode->i_atime.tv_sec = stat->atime;
1170        inode->i_mtime.tv_sec = stat->mtime;
1171        inode->i_ctime.tv_sec = stat->mtime;
1172
1173        inode->i_uid = v9ses->dfltuid;
1174        inode->i_gid = v9ses->dfltgid;
1175
1176        if (v9fs_proto_dotu(v9ses)) {
1177                inode->i_uid = stat->n_uid;
1178                inode->i_gid = stat->n_gid;
1179        }
1180        if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1181                if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1182                        /*
1183                         * Hadlink support got added later to
1184                         * to the .u extension. So there can be
1185                         * server out there that doesn't support
1186                         * this even with .u extension. So check
1187                         * for non NULL stat->extension
1188                         */
1189                        strncpy(ext, stat->extension, sizeof(ext));
1190                        /* HARDLINKCOUNT %u */
1191                        sscanf(ext, "%13s %u", tag_name, &i_nlink);
1192                        if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1193                                set_nlink(inode, i_nlink);
1194                }
1195        }
1196        mode = p9mode2perm(v9ses, stat);
1197        mode |= inode->i_mode & ~S_IALLUGO;
1198        inode->i_mode = mode;
1199        i_size_write(inode, stat->length);
1200
1201        /* not real number of blocks, but 512 byte ones ... */
1202        inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1203        v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1204}
1205
1206/**
1207 * v9fs_qid2ino - convert qid into inode number
1208 * @qid: qid to hash
1209 *
1210 * BUG: potential for inode number collisions?
1211 */
1212
1213ino_t v9fs_qid2ino(struct p9_qid *qid)
1214{
1215        u64 path = qid->path + 2;
1216        ino_t i = 0;
1217
1218        if (sizeof(ino_t) == sizeof(path))
1219                memcpy(&i, &path, sizeof(ino_t));
1220        else
1221                i = (ino_t) (path ^ (path >> 32));
1222
1223        return i;
1224}
1225
1226/**
1227 * v9fs_readlink - read a symlink's location (internal version)
1228 * @dentry: dentry for symlink
1229 * @buffer: buffer to load symlink location into
1230 * @buflen: length of buffer
1231 *
1232 */
1233
1234static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1235{
1236        int retval;
1237
1238        struct v9fs_session_info *v9ses;
1239        struct p9_fid *fid;
1240        struct p9_wstat *st;
1241
1242        p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1243        retval = -EPERM;
1244        v9ses = v9fs_dentry2v9ses(dentry);
1245        fid = v9fs_fid_lookup(dentry);
1246        if (IS_ERR(fid))
1247                return PTR_ERR(fid);
1248
1249        if (!v9fs_proto_dotu(v9ses))
1250                return -EBADF;
1251
1252        st = p9_client_stat(fid);
1253        if (IS_ERR(st))
1254                return PTR_ERR(st);
1255
1256        if (!(st->mode & P9_DMSYMLINK)) {
1257                retval = -EINVAL;
1258                goto done;
1259        }
1260
1261        /* copy extension buffer into buffer */
1262        retval = min(strlen(st->extension)+1, (size_t)buflen);
1263        memcpy(buffer, st->extension, retval);
1264
1265        p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n",
1266                 dentry->d_name.name, st->extension, buflen, buffer);
1267
1268done:
1269        p9stat_free(st);
1270        kfree(st);
1271        return retval;
1272}
1273
1274/**
1275 * v9fs_vfs_follow_link - follow a symlink path
1276 * @dentry: dentry for symlink
1277 * @nd: nameidata
1278 *
1279 */
1280
1281static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1282{
1283        int len = 0;
1284        char *link = __getname();
1285
1286        p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
1287
1288        if (!link)
1289                link = ERR_PTR(-ENOMEM);
1290        else {
1291                len = v9fs_readlink(dentry, link, PATH_MAX);
1292
1293                if (len < 0) {
1294                        __putname(link);
1295                        link = ERR_PTR(len);
1296                } else
1297                        link[min(len, PATH_MAX-1)] = 0;
1298        }
1299        nd_set_link(nd, link);
1300
1301        return NULL;
1302}
1303
1304/**
1305 * v9fs_vfs_put_link - release a symlink path
1306 * @dentry: dentry for symlink
1307 * @nd: nameidata
1308 * @p: unused
1309 *
1310 */
1311
1312void
1313v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1314{
1315        char *s = nd_get_link(nd);
1316
1317        p9_debug(P9_DEBUG_VFS, " %s %s\n",
1318                 dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
1319        if (!IS_ERR(s))
1320                __putname(s);
1321}
1322
1323/**
1324 * v9fs_vfs_mkspecial - create a special file
1325 * @dir: inode to create special file in
1326 * @dentry: dentry to create
1327 * @mode: mode to create special file
1328 * @extension: 9p2000.u format extension string representing special file
1329 *
1330 */
1331
1332static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1333        u32 perm, const char *extension)
1334{
1335        struct p9_fid *fid;
1336        struct v9fs_session_info *v9ses;
1337
1338        v9ses = v9fs_inode2v9ses(dir);
1339        if (!v9fs_proto_dotu(v9ses)) {
1340                p9_debug(P9_DEBUG_ERROR, "not extended\n");
1341                return -EPERM;
1342        }
1343
1344        fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1345                                                                P9_OREAD);
1346        if (IS_ERR(fid))
1347                return PTR_ERR(fid);
1348
1349        v9fs_invalidate_inode_attr(dir);
1350        p9_client_clunk(fid);
1351        return 0;
1352}
1353
1354/**
1355 * v9fs_vfs_symlink - helper function to create symlinks
1356 * @dir: directory inode containing symlink
1357 * @dentry: dentry for symlink
1358 * @symname: symlink data
1359 *
1360 * See Also: 9P2000.u RFC for more information
1361 *
1362 */
1363
1364static int
1365v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1366{
1367        p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1368                 dir->i_ino, dentry->d_name.name, symname);
1369
1370        return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1371}
1372
1373/**
1374 * v9fs_vfs_link - create a hardlink
1375 * @old_dentry: dentry for file to link to
1376 * @dir: inode destination for new link
1377 * @dentry: dentry for link
1378 *
1379 */
1380
1381static int
1382v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1383              struct dentry *dentry)
1384{
1385        int retval;
1386        char *name;
1387        struct p9_fid *oldfid;
1388
1389        p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1390                 dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
1391
1392        oldfid = v9fs_fid_clone(old_dentry);
1393        if (IS_ERR(oldfid))
1394                return PTR_ERR(oldfid);
1395
1396        name = __getname();
1397        if (unlikely(!name)) {
1398                retval = -ENOMEM;
1399                goto clunk_fid;
1400        }
1401
1402        sprintf(name, "%d\n", oldfid->fid);
1403        retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1404        __putname(name);
1405        if (!retval) {
1406                v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1407                v9fs_invalidate_inode_attr(dir);
1408        }
1409clunk_fid:
1410        p9_client_clunk(oldfid);
1411        return retval;
1412}
1413
1414/**
1415 * v9fs_vfs_mknod - create a special file
1416 * @dir: inode destination for new link
1417 * @dentry: dentry for file
1418 * @mode: mode for creation
1419 * @rdev: device associated with special file
1420 *
1421 */
1422
1423static int
1424v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1425{
1426        struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1427        int retval;
1428        char *name;
1429        u32 perm;
1430
1431        p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
1432                 dir->i_ino, dentry->d_name.name, mode,
1433                 MAJOR(rdev), MINOR(rdev));
1434
1435        if (!new_valid_dev(rdev))
1436                return -EINVAL;
1437
1438        name = __getname();
1439        if (!name)
1440                return -ENOMEM;
1441        /* build extension */
1442        if (S_ISBLK(mode))
1443                sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1444        else if (S_ISCHR(mode))
1445                sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1446        else if (S_ISFIFO(mode))
1447                *name = 0;
1448        else if (S_ISSOCK(mode))
1449                *name = 0;
1450        else {
1451                __putname(name);
1452                return -EINVAL;
1453        }
1454
1455        perm = unixmode2p9mode(v9ses, mode);
1456        retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1457        __putname(name);
1458
1459        return retval;
1460}
1461
1462int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1463{
1464        int umode;
1465        dev_t rdev;
1466        loff_t i_size;
1467        struct p9_wstat *st;
1468        struct v9fs_session_info *v9ses;
1469
1470        v9ses = v9fs_inode2v9ses(inode);
1471        st = p9_client_stat(fid);
1472        if (IS_ERR(st))
1473                return PTR_ERR(st);
1474        /*
1475         * Don't update inode if the file type is different
1476         */
1477        umode = p9mode2unixmode(v9ses, st, &rdev);
1478        if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1479                goto out;
1480
1481        spin_lock(&inode->i_lock);
1482        /*
1483         * We don't want to refresh inode->i_size,
1484         * because we may have cached data
1485         */
1486        i_size = inode->i_size;
1487        v9fs_stat2inode(st, inode, inode->i_sb);
1488        if (v9ses->cache)
1489                inode->i_size = i_size;
1490        spin_unlock(&inode->i_lock);
1491out:
1492        p9stat_free(st);
1493        kfree(st);
1494        return 0;
1495}
1496
1497static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1498        .create = v9fs_vfs_create,
1499        .lookup = v9fs_vfs_lookup,
1500        .atomic_open = v9fs_vfs_atomic_open,
1501        .symlink = v9fs_vfs_symlink,
1502        .link = v9fs_vfs_link,
1503        .unlink = v9fs_vfs_unlink,
1504        .mkdir = v9fs_vfs_mkdir,
1505        .rmdir = v9fs_vfs_rmdir,
1506        .mknod = v9fs_vfs_mknod,
1507        .rename = v9fs_vfs_rename,
1508        .getattr = v9fs_vfs_getattr,
1509        .setattr = v9fs_vfs_setattr,
1510};
1511
1512static const struct inode_operations v9fs_dir_inode_operations = {
1513        .create = v9fs_vfs_create,
1514        .lookup = v9fs_vfs_lookup,
1515        .atomic_open = v9fs_vfs_atomic_open,
1516        .unlink = v9fs_vfs_unlink,
1517        .mkdir = v9fs_vfs_mkdir,
1518        .rmdir = v9fs_vfs_rmdir,
1519        .mknod = v9fs_vfs_mknod,
1520        .rename = v9fs_vfs_rename,
1521        .getattr = v9fs_vfs_getattr,
1522        .setattr = v9fs_vfs_setattr,
1523};
1524
1525static const struct inode_operations v9fs_file_inode_operations = {
1526        .getattr = v9fs_vfs_getattr,
1527        .setattr = v9fs_vfs_setattr,
1528};
1529
1530static const struct inode_operations v9fs_symlink_inode_operations = {
1531        .readlink = generic_readlink,
1532        .follow_link = v9fs_vfs_follow_link,
1533        .put_link = v9fs_vfs_put_link,
1534        .getattr = v9fs_vfs_getattr,
1535        .setattr = v9fs_vfs_setattr,
1536};
1537
1538
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