LXR linux/fs/hpfs/dir.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/hpfs/dir.c
   4 *
   5 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
   6 *
   7 *  directory VFS functions
   8 */
   9
  10#include <linux/slab.h>
  11#include "hpfs_fn.h"
  12
  13static int hpfs_dir_release(struct inode *inode, struct file *filp)
  14{
  15        hpfs_lock(inode->i_sb);
  16        hpfs_del_pos(inode, &filp->f_pos);
  17        /*hpfs_write_if_changed(inode);*/
  18        hpfs_unlock(inode->i_sb);
  19        return 0;
  20}
  21
  22/* This is slow, but it's not used often */
  23
  24static loff_t hpfs_dir_lseek(struct file *filp, loff_t off, int whence)
  25{
  26        loff_t new_off = off + (whence == 1 ? filp->f_pos : 0);
  27        loff_t pos;
  28        struct quad_buffer_head qbh;
  29        struct inode *i = file_inode(filp);
  30        struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
  31        struct super_block *s = i->i_sb;
  32
  33        /* Somebody else will have to figure out what to do here */
  34        if (whence == SEEK_DATA || whence == SEEK_HOLE)
  35                return -EINVAL;
  36
  37        inode_lock(i);
  38        hpfs_lock(s);
  39
  40        /*pr_info("dir lseek\n");*/
  41        if (new_off == 0 || new_off == 1 || new_off == 11 || new_off == 12 || new_off == 13) goto ok;
  42        pos = ((loff_t) hpfs_de_as_down_as_possible(s, hpfs_inode->i_dno) << 4) + 1;
  43        while (pos != new_off) {
  44                if (map_pos_dirent(i, &pos, &qbh)) hpfs_brelse4(&qbh);
  45                else goto fail;
  46                if (pos == 12) goto fail;
  47        }
  48        if (unlikely(hpfs_add_pos(i, &filp->f_pos) < 0)) {
  49                hpfs_unlock(s);
  50                inode_unlock(i);
  51                return -ENOMEM;
  52        }
  53ok:
  54        filp->f_pos = new_off;
  55        hpfs_unlock(s);
  56        inode_unlock(i);
  57        return new_off;
  58fail:
  59        /*pr_warn("illegal lseek: %016llx\n", new_off);*/
  60        hpfs_unlock(s);
  61        inode_unlock(i);
  62        return -ESPIPE;
  63}
  64
  65static int hpfs_readdir(struct file *file, struct dir_context *ctx)
  66{
  67        struct inode *inode = file_inode(file);
  68        struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
  69        struct quad_buffer_head qbh;
  70        struct hpfs_dirent *de;
  71        int lc;
  72        loff_t next_pos;
  73        unsigned char *tempname;
  74        int c1, c2 = 0;
  75        int ret = 0;
  76
  77        hpfs_lock(inode->i_sb);
  78
  79        if (hpfs_sb(inode->i_sb)->sb_chk) {
  80                if (hpfs_chk_sectors(inode->i_sb, inode->i_ino, 1, "dir_fnode")) {
  81                        ret = -EFSERROR;
  82                        goto out;
  83                }
  84                if (hpfs_chk_sectors(inode->i_sb, hpfs_inode->i_dno, 4, "dir_dnode")) {
  85                        ret = -EFSERROR;
  86                        goto out;
  87                }
  88        }
  89        if (hpfs_sb(inode->i_sb)->sb_chk >= 2) {
  90                struct buffer_head *bh;
  91                struct fnode *fno;
  92                int e = 0;
  93                if (!(fno = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) {
  94                        ret = -EIOERROR;
  95                        goto out;
  96                }
  97                if (!fnode_is_dir(fno)) {
  98                        e = 1;
  99                        hpfs_error(inode->i_sb, "not a directory, fnode %08lx",
 100                                        (unsigned long)inode->i_ino);
 101                }
 102                if (hpfs_inode->i_dno != le32_to_cpu(fno->u.external[0].disk_secno)) {
 103                        e = 1;
 104                        hpfs_error(inode->i_sb, "corrupted inode: i_dno == %08x, fnode -> dnode == %08x", hpfs_inode->i_dno, le32_to_cpu(fno->u.external[0].disk_secno));
 105                }
 106                brelse(bh);
 107                if (e) {
 108                        ret = -EFSERROR;
 109                        goto out;
 110                }
 111        }
 112        lc = hpfs_sb(inode->i_sb)->sb_lowercase;
 113        if (ctx->pos == 12) { /* diff -r requires this (note, that diff -r */
 114                ctx->pos = 13; /* also fails on msdos filesystem in 2.0) */
 115                goto out;
 116        }
 117        if (ctx->pos == 13) {
 118                ret = -ENOENT;
 119                goto out;
 120        }
 121        
 122        while (1) {
 123                again:
 124                /* This won't work when cycle is longer than number of dirents
 125                   accepted by filldir, but what can I do?
 126                   maybe killall -9 ls helps */
 127                if (hpfs_sb(inode->i_sb)->sb_chk)
 128                        if (hpfs_stop_cycles(inode->i_sb, ctx->pos, &c1, &c2, "hpfs_readdir")) {
 129                                ret = -EFSERROR;
 130                                goto out;
 131                        }
 132                if (ctx->pos == 12)
 133                        goto out;
 134                if (ctx->pos == 3 || ctx->pos == 4 || ctx->pos == 5) {
 135                        pr_err("pos==%d\n", (int)ctx->pos);
 136                        goto out;
 137                }
 138                if (ctx->pos == 0) {
 139                        if (!dir_emit_dot(file, ctx))
 140                                goto out;
 141                        ctx->pos = 11;
 142                }
 143                if (ctx->pos == 11) {
 144                        if (!dir_emit(ctx, "..", 2, hpfs_inode->i_parent_dir, DT_DIR))
 145                                goto out;
 146                        ctx->pos = 1;
 147                }
 148                if (ctx->pos == 1) {
 149                        ret = hpfs_add_pos(inode, &file->f_pos);
 150                        if (unlikely(ret < 0))
 151                                goto out;
 152                        ctx->pos = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, hpfs_inode->i_dno) << 4) + 1;
 153                }
 154                next_pos = ctx->pos;
 155                if (!(de = map_pos_dirent(inode, &next_pos, &qbh))) {
 156                        ctx->pos = next_pos;
 157                        ret = -EIOERROR;
 158                        goto out;
 159                }
 160                if (de->first || de->last) {
 161                        if (hpfs_sb(inode->i_sb)->sb_chk) {
 162                                if (de->first && !de->last && (de->namelen != 2
 163                                    || de ->name[0] != 1 || de->name[1] != 1))
 164                                        hpfs_error(inode->i_sb, "hpfs_readdir: bad ^A^A entry; pos = %08lx", (unsigned long)ctx->pos);
 165                                if (de->last && (de->namelen != 1 || de ->name[0] != 255))
 166                                        hpfs_error(inode->i_sb, "hpfs_readdir: bad \\377 entry; pos = %08lx", (unsigned long)ctx->pos);
 167                        }
 168                        hpfs_brelse4(&qbh);
 169                        ctx->pos = next_pos;
 170                        goto again;
 171                }
 172                tempname = hpfs_translate_name(inode->i_sb, de->name, de->namelen, lc, de->not_8x3);
 173                if (!dir_emit(ctx, tempname, de->namelen, le32_to_cpu(de->fnode), DT_UNKNOWN)) {
 174                        if (tempname != de->name) kfree(tempname);
 175                        hpfs_brelse4(&qbh);
 176                        goto out;
 177                }
 178                ctx->pos = next_pos;
 179                if (tempname != de->name) kfree(tempname);
 180                hpfs_brelse4(&qbh);
 181        }
 182out:
 183        hpfs_unlock(inode->i_sb);
 184        return ret;
 185}
 186
 187/*
 188 * lookup.  Search the specified directory for the specified name, set
 189 * *result to the corresponding inode.
 190 *
 191 * lookup uses the inode number to tell read_inode whether it is reading
 192 * the inode of a directory or a file -- file ino's are odd, directory
 193 * ino's are even.  read_inode avoids i/o for file inodes; everything
 194 * needed is up here in the directory.  (And file fnodes are out in
 195 * the boondocks.)
 196 *
 197 *    - M.P.: this is over, sometimes we've got to read file's fnode for eas
 198 *            inode numbers are just fnode sector numbers; iget lock is used
 199 *            to tell read_inode to read fnode or not.
 200 */
 201
 202struct dentry *hpfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 203{
 204        const unsigned char *name = dentry->d_name.name;
 205        unsigned len = dentry->d_name.len;
 206        struct quad_buffer_head qbh;
 207        struct hpfs_dirent *de;
 208        ino_t ino;
 209        int err;
 210        struct inode *result = NULL;
 211        struct hpfs_inode_info *hpfs_result;
 212
 213        hpfs_lock(dir->i_sb);
 214        if ((err = hpfs_chk_name(name, &len))) {
 215                if (err == -ENAMETOOLONG) {
 216                        hpfs_unlock(dir->i_sb);
 217                        return ERR_PTR(-ENAMETOOLONG);
 218                }
 219                goto end_add;
 220        }
 221
 222        /*
 223         * '.' and '..' will never be passed here.
 224         */
 225
 226        de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, NULL, &qbh);
 227
 228        /*
 229         * This is not really a bailout, just means file not found.
 230         */
 231
 232        if (!de) goto end;
 233
 234        /*
 235         * Get inode number, what we're after.
 236         */
 237
 238        ino = le32_to_cpu(de->fnode);
 239
 240        /*
 241         * Go find or make an inode.
 242         */
 243
 244        result = iget_locked(dir->i_sb, ino);
 245        if (!result) {
 246                hpfs_error(dir->i_sb, "hpfs_lookup: can't get inode");
 247                result = ERR_PTR(-ENOMEM);
 248                goto bail1;
 249        }
 250        if (result->i_state & I_NEW) {
 251                hpfs_init_inode(result);
 252                if (de->directory)
 253                        hpfs_read_inode(result);
 254                else if (le32_to_cpu(de->ea_size) && hpfs_sb(dir->i_sb)->sb_eas)
 255                        hpfs_read_inode(result);
 256                else {
 257                        result->i_mode |= S_IFREG;
 258                        result->i_mode &= ~0111;
 259                        result->i_op = &hpfs_file_iops;
 260                        result->i_fop = &hpfs_file_ops;
 261                        set_nlink(result, 1);
 262                }
 263                unlock_new_inode(result);
 264        }
 265        hpfs_result = hpfs_i(result);
 266        if (!de->directory) hpfs_result->i_parent_dir = dir->i_ino;
 267
 268        if (de->has_acl || de->has_xtd_perm) if (!sb_rdonly(dir->i_sb)) {
 269                hpfs_error(result->i_sb, "ACLs or XPERM found. This is probably HPFS386. This driver doesn't support it now. Send me some info on these structures");
 270                iput(result);
 271                result = ERR_PTR(-EINVAL);
 272                goto bail1;
 273        }
 274
 275        /*
 276         * Fill in the info from the directory if this is a newly created
 277         * inode.
 278         */
 279
 280        if (!result->i_ctime.tv_sec) {
 281                if (!(result->i_ctime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->creation_date))))
 282                        result->i_ctime.tv_sec = 1;
 283                result->i_ctime.tv_nsec = 0;
 284                result->i_mtime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->write_date));
 285                result->i_mtime.tv_nsec = 0;
 286                result->i_atime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->read_date));
 287                result->i_atime.tv_nsec = 0;
 288                hpfs_result->i_ea_size = le32_to_cpu(de->ea_size);
 289                if (!hpfs_result->i_ea_mode && de->read_only)
 290                        result->i_mode &= ~0222;
 291                if (!de->directory) {
 292                        if (result->i_size == -1) {
 293                                result->i_size = le32_to_cpu(de->file_size);
 294                                result->i_data.a_ops = &hpfs_aops;
 295                                hpfs_i(result)->mmu_private = result->i_size;
 296                        /*
 297                         * i_blocks should count the fnode and any anodes.
 298                         * We count 1 for the fnode and don't bother about
 299                         * anodes -- the disk heads are on the directory band
 300                         * and we want them to stay there.
 301                         */
 302                                result->i_blocks = 1 + ((result->i_size + 511) >> 9);
 303                        }
 304                }
 305        }
 306
 307bail1:
 308        hpfs_brelse4(&qbh);
 309
 310        /*
 311         * Made it.
 312         */
 313
 314end:
 315end_add:
 316        hpfs_unlock(dir->i_sb);
 317        return d_splice_alias(result, dentry);
 318}
 319
 320const struct file_operations hpfs_dir_ops =
 321{
 322        .llseek         = hpfs_dir_lseek,
 323        .read           = generic_read_dir,
 324        .iterate_shared = hpfs_readdir,
 325        .release        = hpfs_dir_release,
 326        .fsync          = hpfs_file_fsync,
 327        .unlocked_ioctl = hpfs_ioctl,
 328        .compat_ioctl   = compat_ptr_ioctl,
 329};
 330