LXR linux/fs/qnx4/dir.c

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