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/smp_lock.h>
  15#include <linux/buffer_head.h>
  16#include "qnx4.h"
  17
  18static int qnx4_readdir(struct file *filp, void *dirent, filldir_t filldir)
  19{
  20        struct inode *inode = filp->f_path.dentry->d_inode;
  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(("qnx4_readdir:i_size = %ld\n", (long) inode->i_size));
  30        QNX4DEBUG(("filp->f_pos         = %ld\n", (long) filp->f_pos));
  31
  32        lock_kernel();
  33
  34        while (filp->f_pos < inode->i_size) {
  35                blknum = qnx4_block_map( inode, filp->f_pos >> QNX4_BLOCK_SIZE_BITS );
  36                bh = sb_bread(inode->i_sb, blknum);
  37                if(bh==NULL) {
  38                        printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", blknum);
  39                        break;
  40                }
  41                ix = (int)(filp->f_pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
  42                while (ix < QNX4_INODES_PER_BLOCK) {
  43                        offset = ix * QNX4_DIR_ENTRY_SIZE;
  44                        de = (struct qnx4_inode_entry *) (bh->b_data + offset);
  45                        size = strlen(de->di_fname);
  46                        if (size) {
  47                                if ( !( de->di_status & QNX4_FILE_LINK ) && size > QNX4_SHORT_NAME_MAX )
  48                                        size = QNX4_SHORT_NAME_MAX;
  49                                else if ( size > QNX4_NAME_MAX )
  50                                        size = QNX4_NAME_MAX;
  51
  52                                if ( ( de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK) ) != 0 ) {
  53                                        QNX4DEBUG(("qnx4_readdir:%.*s\n", size, de->di_fname));
  54                                        if ( ( de->di_status & QNX4_FILE_LINK ) == 0 )
  55                                                ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
  56                                        else {
  57                                                le  = (struct qnx4_link_info*)de;
  58                                                ino = ( le32_to_cpu(le->dl_inode_blk) - 1 ) *
  59                                                        QNX4_INODES_PER_BLOCK +
  60                                                        le->dl_inode_ndx;
  61                                        }
  62                                        if (filldir(dirent, de->di_fname, size, filp->f_pos, ino, DT_UNKNOWN) < 0) {
  63                                                brelse(bh);
  64                                                goto out;
  65                                        }
  66                                }
  67                        }
  68                        ix++;
  69                        filp->f_pos += QNX4_DIR_ENTRY_SIZE;
  70                }
  71                brelse(bh);
  72        }
  73out:
  74        unlock_kernel();
  75        return 0;
  76}
  77
  78const struct file_operations qnx4_dir_operations =
  79{
  80        .read           = generic_read_dir,
  81        .readdir        = qnx4_readdir,
  82        .fsync          = simple_fsync,
  83};
  84
  85const struct inode_operations qnx4_dir_inode_operations =
  86{
  87        .lookup         = qnx4_lookup,
  88};
  89