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
  17 static 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
  70 const struct file_operations qnx4_dir_operations =
  71 {
  72         .llseek         = generic_file_llseek,
  73         .read           = generic_read_dir,
  74         .iterate        = qnx4_readdir,
  75         .fsync          = generic_file_fsync,
  76 };
  77
  78 const struct inode_operations qnx4_dir_inode_operations =
  79 {
  80         .lookup         = qnx4_lookup,
  81 };