root/fs/hpfs/dir.c

DEFINITIONS

1. hpfs_dir_release
2. hpfs_dir_lseek
3. hpfs_readdir
4. hpfs_lookup

   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 
  13 static 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 
  24 static 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         }
  53 ok:
  54         filp->f_pos = new_off;
  55         hpfs_unlock(s);
  56         inode_unlock(i);
  57         return new_off;
  58 fail:
  59         /*pr_warn("illegal lseek: %016llx\n", new_off);*/
  60         hpfs_unlock(s);
  61         inode_unlock(i);
  62         return -ESPIPE;
  63 }
  64 
  65 static 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         }
 182 out:
 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 
 202 struct 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 
 307 bail1:
 308         hpfs_brelse4(&qbh);
 309 
 310         /*
 311          * Made it.
 312          */
 313 
 314 end:
 315 end_add:
 316         hpfs_unlock(dir->i_sb);
 317         return d_splice_alias(result, dentry);
 318 }
 319 
 320 const 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 };