linux/fs/hfsplus/dir.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/hfsplus/dir.c
   4 *
   5 * Copyright (C) 2001
   6 * Brad Boyer (flar@allandria.com)
   7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
   8 *
   9 * Handling of directories
  10 */
  11
  12#include <linux/errno.h>
  13#include <linux/fs.h>
  14#include <linux/slab.h>
  15#include <linux/random.h>
  16#include <linux/nls.h>
  17
  18#include "hfsplus_fs.h"
  19#include "hfsplus_raw.h"
  20#include "xattr.h"
  21
  22static inline void hfsplus_instantiate(struct dentry *dentry,
  23                                       struct inode *inode, u32 cnid)
  24{
  25        dentry->d_fsdata = (void *)(unsigned long)cnid;
  26        d_instantiate(dentry, inode);
  27}
  28
  29/* Find the entry inside dir named dentry->d_name */
  30static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
  31                                     unsigned int flags)
  32{
  33        struct inode *inode = NULL;
  34        struct hfs_find_data fd;
  35        struct super_block *sb;
  36        hfsplus_cat_entry entry;
  37        int err;
  38        u32 cnid, linkid = 0;
  39        u16 type;
  40
  41        sb = dir->i_sb;
  42
  43        dentry->d_fsdata = NULL;
  44        err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
  45        if (err)
  46                return ERR_PTR(err);
  47        err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
  48                        &dentry->d_name);
  49        if (unlikely(err < 0))
  50                goto fail;
  51again:
  52        err = hfs_brec_read(&fd, &entry, sizeof(entry));
  53        if (err) {
  54                if (err == -ENOENT) {
  55                        hfs_find_exit(&fd);
  56                        /* No such entry */
  57                        inode = NULL;
  58                        goto out;
  59                }
  60                goto fail;
  61        }
  62        type = be16_to_cpu(entry.type);
  63        if (type == HFSPLUS_FOLDER) {
  64                if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
  65                        err = -EIO;
  66                        goto fail;
  67                }
  68                cnid = be32_to_cpu(entry.folder.id);
  69                dentry->d_fsdata = (void *)(unsigned long)cnid;
  70        } else if (type == HFSPLUS_FILE) {
  71                if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
  72                        err = -EIO;
  73                        goto fail;
  74                }
  75                cnid = be32_to_cpu(entry.file.id);
  76                if (entry.file.user_info.fdType ==
  77                                cpu_to_be32(HFSP_HARDLINK_TYPE) &&
  78                                entry.file.user_info.fdCreator ==
  79                                cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
  80                                HFSPLUS_SB(sb)->hidden_dir &&
  81                                (entry.file.create_date ==
  82                                        HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
  83                                                create_date ||
  84                                entry.file.create_date ==
  85                                        HFSPLUS_I(d_inode(sb->s_root))->
  86                                                create_date)) {
  87                        struct qstr str;
  88                        char name[32];
  89
  90                        if (dentry->d_fsdata) {
  91                                /*
  92                                 * We found a link pointing to another link,
  93                                 * so ignore it and treat it as regular file.
  94                                 */
  95                                cnid = (unsigned long)dentry->d_fsdata;
  96                                linkid = 0;
  97                        } else {
  98                                dentry->d_fsdata = (void *)(unsigned long)cnid;
  99                                linkid =
 100                                        be32_to_cpu(entry.file.permissions.dev);
 101                                str.len = sprintf(name, "iNode%d", linkid);
 102                                str.name = name;
 103                                err = hfsplus_cat_build_key(sb, fd.search_key,
 104                                        HFSPLUS_SB(sb)->hidden_dir->i_ino,
 105                                        &str);
 106                                if (unlikely(err < 0))
 107                                        goto fail;
 108                                goto again;
 109                        }
 110                } else if (!dentry->d_fsdata)
 111                        dentry->d_fsdata = (void *)(unsigned long)cnid;
 112        } else {
 113                pr_err("invalid catalog entry type in lookup\n");
 114                err = -EIO;
 115                goto fail;
 116        }
 117        hfs_find_exit(&fd);
 118        inode = hfsplus_iget(dir->i_sb, cnid);
 119        if (IS_ERR(inode))
 120                return ERR_CAST(inode);
 121        if (S_ISREG(inode->i_mode))
 122                HFSPLUS_I(inode)->linkid = linkid;
 123out:
 124        return d_splice_alias(inode, dentry);
 125fail:
 126        hfs_find_exit(&fd);
 127        return ERR_PTR(err);
 128}
 129
 130static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
 131{
 132        struct inode *inode = file_inode(file);
 133        struct super_block *sb = inode->i_sb;
 134        int len, err;
 135        char *strbuf;
 136        hfsplus_cat_entry entry;
 137        struct hfs_find_data fd;
 138        struct hfsplus_readdir_data *rd;
 139        u16 type;
 140
 141        if (file->f_pos >= inode->i_size)
 142                return 0;
 143
 144        err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
 145        if (err)
 146                return err;
 147        strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
 148        if (!strbuf) {
 149                err = -ENOMEM;
 150                goto out;
 151        }
 152        hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
 153        err = hfs_brec_find(&fd, hfs_find_rec_by_key);
 154        if (err)
 155                goto out;
 156
 157        if (ctx->pos == 0) {
 158                /* This is completely artificial... */
 159                if (!dir_emit_dot(file, ctx))
 160                        goto out;
 161                ctx->pos = 1;
 162        }
 163        if (ctx->pos == 1) {
 164                if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
 165                        err = -EIO;
 166                        goto out;
 167                }
 168
 169                hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
 170                        fd.entrylength);
 171                if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
 172                        pr_err("bad catalog folder thread\n");
 173                        err = -EIO;
 174                        goto out;
 175                }
 176                if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
 177                        pr_err("truncated catalog thread\n");
 178                        err = -EIO;
 179                        goto out;
 180                }
 181                if (!dir_emit(ctx, "..", 2,
 182                            be32_to_cpu(entry.thread.parentID), DT_DIR))
 183                        goto out;
 184                ctx->pos = 2;
 185        }
 186        if (ctx->pos >= inode->i_size)
 187                goto out;
 188        err = hfs_brec_goto(&fd, ctx->pos - 1);
 189        if (err)
 190                goto out;
 191        for (;;) {
 192                if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
 193                        pr_err("walked past end of dir\n");
 194                        err = -EIO;
 195                        goto out;
 196                }
 197
 198                if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
 199                        err = -EIO;
 200                        goto out;
 201                }
 202
 203                hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
 204                        fd.entrylength);
 205                type = be16_to_cpu(entry.type);
 206                len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
 207                err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
 208                if (err)
 209                        goto out;
 210                if (type == HFSPLUS_FOLDER) {
 211                        if (fd.entrylength <
 212                                        sizeof(struct hfsplus_cat_folder)) {
 213                                pr_err("small dir entry\n");
 214                                err = -EIO;
 215                                goto out;
 216                        }
 217                        if (HFSPLUS_SB(sb)->hidden_dir &&
 218                            HFSPLUS_SB(sb)->hidden_dir->i_ino ==
 219                                        be32_to_cpu(entry.folder.id))
 220                                goto next;
 221                        if (!dir_emit(ctx, strbuf, len,
 222                                    be32_to_cpu(entry.folder.id), DT_DIR))
 223                                break;
 224                } else if (type == HFSPLUS_FILE) {
 225                        u16 mode;
 226                        unsigned type = DT_UNKNOWN;
 227
 228                        if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
 229                                pr_err("small file entry\n");
 230                                err = -EIO;
 231                                goto out;
 232                        }
 233
 234                        mode = be16_to_cpu(entry.file.permissions.mode);
 235                        if (S_ISREG(mode))
 236                                type = DT_REG;
 237                        else if (S_ISLNK(mode))
 238                                type = DT_LNK;
 239                        else if (S_ISFIFO(mode))
 240                                type = DT_FIFO;
 241                        else if (S_ISCHR(mode))
 242                                type = DT_CHR;
 243                        else if (S_ISBLK(mode))
 244                                type = DT_BLK;
 245                        else if (S_ISSOCK(mode))
 246                                type = DT_SOCK;
 247
 248                        if (!dir_emit(ctx, strbuf, len,
 249                                      be32_to_cpu(entry.file.id), type))
 250                                break;
 251                } else {
 252                        pr_err("bad catalog entry type\n");
 253                        err = -EIO;
 254                        goto out;
 255                }
 256next:
 257                ctx->pos++;
 258                if (ctx->pos >= inode->i_size)
 259                        goto out;
 260                err = hfs_brec_goto(&fd, 1);
 261                if (err)
 262                        goto out;
 263        }
 264        rd = file->private_data;
 265        if (!rd) {
 266                rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
 267                if (!rd) {
 268                        err = -ENOMEM;
 269                        goto out;
 270                }
 271                file->private_data = rd;
 272                rd->file = file;
 273                spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
 274                list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
 275                spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
 276        }
 277        /*
 278         * Can be done after the list insertion; exclusion with
 279         * hfsplus_delete_cat() is provided by directory lock.
 280         */
 281        memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
 282out:
 283        kfree(strbuf);
 284        hfs_find_exit(&fd);
 285        return err;
 286}
 287
 288static int hfsplus_dir_release(struct inode *inode, struct file *file)
 289{
 290        struct hfsplus_readdir_data *rd = file->private_data;
 291        if (rd) {
 292                spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
 293                list_del(&rd->list);
 294                spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
 295                kfree(rd);
 296        }
 297        return 0;
 298}
 299
 300static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
 301                        struct dentry *dst_dentry)
 302{
 303        struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
 304        struct inode *inode = d_inode(src_dentry);
 305        struct inode *src_dir = d_inode(src_dentry->d_parent);
 306        struct qstr str;
 307        char name[32];
 308        u32 cnid, id;
 309        int res;
 310
 311        if (HFSPLUS_IS_RSRC(inode))
 312                return -EPERM;
 313        if (!S_ISREG(inode->i_mode))
 314                return -EPERM;
 315
 316        mutex_lock(&sbi->vh_mutex);
 317        if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
 318                for (;;) {
 319                        get_random_bytes(&id, sizeof(cnid));
 320                        id &= 0x3fffffff;
 321                        str.name = name;
 322                        str.len = sprintf(name, "iNode%d", id);
 323                        res = hfsplus_rename_cat(inode->i_ino,
 324                                                 src_dir, &src_dentry->d_name,
 325                                                 sbi->hidden_dir, &str);
 326                        if (!res)
 327                                break;
 328                        if (res != -EEXIST)
 329                                goto out;
 330                }
 331                HFSPLUS_I(inode)->linkid = id;
 332                cnid = sbi->next_cnid++;
 333                src_dentry->d_fsdata = (void *)(unsigned long)cnid;
 334                res = hfsplus_create_cat(cnid, src_dir,
 335                        &src_dentry->d_name, inode);
 336                if (res)
 337                        /* panic? */
 338                        goto out;
 339                sbi->file_count++;
 340        }
 341        cnid = sbi->next_cnid++;
 342        res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
 343        if (res)
 344                goto out;
 345
 346        inc_nlink(inode);
 347        hfsplus_instantiate(dst_dentry, inode, cnid);
 348        ihold(inode);
 349        inode->i_ctime = current_time(inode);
 350        mark_inode_dirty(inode);
 351        sbi->file_count++;
 352        hfsplus_mark_mdb_dirty(dst_dir->i_sb);
 353out:
 354        mutex_unlock(&sbi->vh_mutex);
 355        return res;
 356}
 357
 358static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
 359{
 360        struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 361        struct inode *inode = d_inode(dentry);
 362        struct qstr str;
 363        char name[32];
 364        u32 cnid;
 365        int res;
 366
 367        if (HFSPLUS_IS_RSRC(inode))
 368                return -EPERM;
 369
 370        mutex_lock(&sbi->vh_mutex);
 371        cnid = (u32)(unsigned long)dentry->d_fsdata;
 372        if (inode->i_ino == cnid &&
 373            atomic_read(&HFSPLUS_I(inode)->opencnt)) {
 374                str.name = name;
 375                str.len = sprintf(name, "temp%lu", inode->i_ino);
 376                res = hfsplus_rename_cat(inode->i_ino,
 377                                         dir, &dentry->d_name,
 378                                         sbi->hidden_dir, &str);
 379                if (!res) {
 380                        inode->i_flags |= S_DEAD;
 381                        drop_nlink(inode);
 382                }
 383                goto out;
 384        }
 385        res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
 386        if (res)
 387                goto out;
 388
 389        if (inode->i_nlink > 0)
 390                drop_nlink(inode);
 391        if (inode->i_ino == cnid)
 392                clear_nlink(inode);
 393        if (!inode->i_nlink) {
 394                if (inode->i_ino != cnid) {
 395                        sbi->file_count--;
 396                        if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
 397                                res = hfsplus_delete_cat(inode->i_ino,
 398                                                         sbi->hidden_dir,
 399                                                         NULL);
 400                                if (!res)
 401                                        hfsplus_delete_inode(inode);
 402                        } else
 403                                inode->i_flags |= S_DEAD;
 404                } else
 405                        hfsplus_delete_inode(inode);
 406        } else
 407                sbi->file_count--;
 408        inode->i_ctime = current_time(inode);
 409        mark_inode_dirty(inode);
 410out:
 411        mutex_unlock(&sbi->vh_mutex);
 412        return res;
 413}
 414
 415static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
 416{
 417        struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 418        struct inode *inode = d_inode(dentry);
 419        int res;
 420
 421        if (inode->i_size != 2)
 422                return -ENOTEMPTY;
 423
 424        mutex_lock(&sbi->vh_mutex);
 425        res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
 426        if (res)
 427                goto out;
 428        clear_nlink(inode);
 429        inode->i_ctime = current_time(inode);
 430        hfsplus_delete_inode(inode);
 431        mark_inode_dirty(inode);
 432out:
 433        mutex_unlock(&sbi->vh_mutex);
 434        return res;
 435}
 436
 437static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
 438                           const char *symname)
 439{
 440        struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 441        struct inode *inode;
 442        int res = -ENOMEM;
 443
 444        mutex_lock(&sbi->vh_mutex);
 445        inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
 446        if (!inode)
 447                goto out;
 448
 449        res = page_symlink(inode, symname, strlen(symname) + 1);
 450        if (res)
 451                goto out_err;
 452
 453        res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
 454        if (res)
 455                goto out_err;
 456
 457        res = hfsplus_init_security(inode, dir, &dentry->d_name);
 458        if (res == -EOPNOTSUPP)
 459                res = 0; /* Operation is not supported. */
 460        else if (res) {
 461                /* Try to delete anyway without error analysis. */
 462                hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
 463                goto out_err;
 464        }
 465
 466        hfsplus_instantiate(dentry, inode, inode->i_ino);
 467        mark_inode_dirty(inode);
 468        goto out;
 469
 470out_err:
 471        clear_nlink(inode);
 472        hfsplus_delete_inode(inode);
 473        iput(inode);
 474out:
 475        mutex_unlock(&sbi->vh_mutex);
 476        return res;
 477}
 478
 479static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
 480                         umode_t mode, dev_t rdev)
 481{
 482        struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 483        struct inode *inode;
 484        int res = -ENOMEM;
 485
 486        mutex_lock(&sbi->vh_mutex);
 487        inode = hfsplus_new_inode(dir->i_sb, dir, mode);
 488        if (!inode)
 489                goto out;
 490
 491        if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
 492                init_special_inode(inode, mode, rdev);
 493
 494        res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
 495        if (res)
 496                goto failed_mknod;
 497
 498        res = hfsplus_init_security(inode, dir, &dentry->d_name);
 499        if (res == -EOPNOTSUPP)
 500                res = 0; /* Operation is not supported. */
 501        else if (res) {
 502                /* Try to delete anyway without error analysis. */
 503                hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
 504                goto failed_mknod;
 505        }
 506
 507        hfsplus_instantiate(dentry, inode, inode->i_ino);
 508        mark_inode_dirty(inode);
 509        goto out;
 510
 511failed_mknod:
 512        clear_nlink(inode);
 513        hfsplus_delete_inode(inode);
 514        iput(inode);
 515out:
 516        mutex_unlock(&sbi->vh_mutex);
 517        return res;
 518}
 519
 520static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 521                          bool excl)
 522{
 523        return hfsplus_mknod(dir, dentry, mode, 0);
 524}
 525
 526static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 527{
 528        return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
 529}
 530
 531static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
 532                          struct inode *new_dir, struct dentry *new_dentry,
 533                          unsigned int flags)
 534{
 535        int res;
 536
 537        if (flags & ~RENAME_NOREPLACE)
 538                return -EINVAL;
 539
 540        /* Unlink destination if it already exists */
 541        if (d_really_is_positive(new_dentry)) {
 542                if (d_is_dir(new_dentry))
 543                        res = hfsplus_rmdir(new_dir, new_dentry);
 544                else
 545                        res = hfsplus_unlink(new_dir, new_dentry);
 546                if (res)
 547                        return res;
 548        }
 549
 550        res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
 551                                 old_dir, &old_dentry->d_name,
 552                                 new_dir, &new_dentry->d_name);
 553        if (!res)
 554                new_dentry->d_fsdata = old_dentry->d_fsdata;
 555        return res;
 556}
 557
 558const struct inode_operations hfsplus_dir_inode_operations = {
 559        .lookup                 = hfsplus_lookup,
 560        .create                 = hfsplus_create,
 561        .link                   = hfsplus_link,
 562        .unlink                 = hfsplus_unlink,
 563        .mkdir                  = hfsplus_mkdir,
 564        .rmdir                  = hfsplus_rmdir,
 565        .symlink                = hfsplus_symlink,
 566        .mknod                  = hfsplus_mknod,
 567        .rename                 = hfsplus_rename,
 568        .getattr                = hfsplus_getattr,
 569        .listxattr              = hfsplus_listxattr,
 570};
 571
 572const struct file_operations hfsplus_dir_operations = {
 573        .fsync          = hfsplus_file_fsync,
 574        .read           = generic_read_dir,
 575        .iterate_shared = hfsplus_readdir,
 576        .unlocked_ioctl = hfsplus_ioctl,
 577        .llseek         = generic_file_llseek,
 578        .release        = hfsplus_dir_release,
 579};
 580