LXR linux/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
  18static 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
  71const 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
  79const struct inode_operations qnx4_dir_inode_operations =
  80{
  81        .lookup         = qnx4_lookup,
  82};
  83