fs/qnx4/dir.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * QNX4 file system, Linux implementation.
   4  *
   5  * Version : 0.2.1
   6  *
   7  * Using parts of the xiafs filesystem.
   8  *
   9  * History :
  10  *
  11  * 28-05-1998 by Richard Frowijn : first release.
  12  * 20-06-1998 by Frank Denis : Linux 2.1.99+ & dcache support.
  13  */
  14
  15 #include <linux/buffer_head.h>
  16 #include "qnx4.h"
  17
  18 static int qnx4_readdir(struct file *file, struct dir_context *ctx)
  19 {
  20         struct inode *inode = file_inode(file);
  21         unsigned int offset;
  22         struct buffer_head *bh;
  23         struct qnx4_inode_entry *de;
  24         struct qnx4_link_info *le;
  25         unsigned long blknum;
  26         int ix, ino;
  27         int size;
  28
  29         QNX4DEBUG((KERN_INFO "qnx4_readdir:i_size = %ld\n", (long) inode->i_size));
  30         QNX4DEBUG((KERN_INFO "pos                 = %ld\n", (long) ctx->pos));
  31
  32         while (ctx->pos < inode->i_size) {
  33                 blknum = qnx4_block_map(inode, ctx->pos >> QNX4_BLOCK_SIZE_BITS);
  34                 bh = sb_bread(inode->i_sb, blknum);
  35                 if (bh == NULL) {
  36                         printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", blknum);
  37                         return 0;
  38                 }
  39                 ix = (ctx->pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
  40                 for (; ix < QNX4_INODES_PER_BLOCK; ix++, ctx->pos += QNX4_DIR_ENTRY_SIZE) {
  41                         offset = ix * QNX4_DIR_ENTRY_SIZE;
  42                         de = (struct qnx4_inode_entry *) (bh->b_data + offset);
  43                         if (!de->di_fname[0])
  44                                 continue;
  45                         if (!(de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)))
  46                                 continue;
  47                         if (!(de->di_status & QNX4_FILE_LINK))
  48                                 size = QNX4_SHORT_NAME_MAX;
  49                         else
  50                                 size = QNX4_NAME_MAX;
  51                         size = strnlen(de->di_fname, size);
  52                         QNX4DEBUG((KERN_INFO "qnx4_readdir:%.*s\n", size, de->di_fname));
  53                         if (!(de->di_status & QNX4_FILE_LINK))
  54                                 ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
  55                         else {
  56                                 le  = (struct qnx4_link_info*)de;
  57                                 ino = ( le32_to_cpu(le->dl_inode_blk) - 1 ) *
  58                                         QNX4_INODES_PER_BLOCK +
  59                                         le->dl_inode_ndx;
  60                         }
  61                         if (!dir_emit(ctx, de->di_fname, size, ino, DT_UNKNOWN)) {
  62                                 brelse(bh);
  63                                 return 0;
  64                         }
  65                 }
  66                 brelse(bh);
  67         }
  68         return 0;
  69 }
  70
  71 const struct file_operations qnx4_dir_operations =
  72 {
  73         .llseek         = generic_file_llseek,
  74         .read           = generic_read_dir,
  75         .iterate_shared = qnx4_readdir,
  76         .fsync          = generic_file_fsync,
  77 };
  78
  79 const struct inode_operations qnx4_dir_inode_operations =
  80 {
  81         .lookup         = qnx4_lookup,
  82 };