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/*
* dir.c
*
* Copyright (c) 1999 Al Smith
*
* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
*/
#include <linux/efs.h>
static int efs_readdir(struct file *, void *, filldir_t);
static struct file_operations efs_dir_operations = {
NULL, /* lseek */
NULL, /* read */
NULL, /* write */
efs_readdir,
NULL, /* poll */
NULL, /* ioctl */
NULL, /* no special open code */
NULL, /* flush */
NULL, /* no special release code */
NULL /* fsync */
};
struct inode_operations efs_dir_inode_operations = {
&efs_dir_operations,
NULL, /* create */
efs_lookup,
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
NULL, /* readlink */
NULL, /* follow_link */
NULL, /* readpage */
NULL, /* writepage */
efs_bmap,
NULL, /* truncate */
NULL /* permission */
};
/* read the next entry for a given directory */
static int efs_readdir(struct file *filp, void *dirent, filldir_t filldir) {
struct inode *inode = filp->f_dentry->d_inode;
struct efs_in_info *ini = (struct efs_in_info *) &inode->u.generic_ip;
struct buffer_head *bh;
struct efs_dir *dirblock;
struct efs_dentry *dirslot;
efs_ino_t inodenum;
efs_block_t block;
int slot, namelen, numslots;
char *nameptr;
if (!inode || !S_ISDIR(inode->i_mode))
return -EBADF;
if (ini->numextents != 1)
printk("EFS: WARNING: readdir(): more than one extent\n");
if (inode->i_size & (EFS_BLOCKSIZE-1))
printk("EFS: WARNING: readdir(): directory size not a multiple of EFS_BLOCKSIZE\n");
/* work out the block where this entry can be found */
block = filp->f_pos >> EFS_BLOCKSIZE_BITS;
/* don't read past last entry */
if (block > inode->i_blocks) return 0;
/* read the dir block */
bh = bread(inode->i_dev, efs_bmap(inode, block), EFS_BLOCKSIZE);
if (!bh) {
printk("EFS: readdir(): failed to read dir block %d\n", block);
return 0;
}
dirblock = (struct efs_dir *) bh->b_data;
if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
printk("EFS: readdir(): invalid directory block\n");
brelse(bh);
return(0);
}
slot = filp->f_pos & 0xff;
dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
numslots = dirblock->slots;
inodenum = be32_to_cpu(dirslot->inode);
namelen = dirslot->namelen;
nameptr = dirslot->name;
#ifdef DEBUG
printk("EFS: dent #%d: inode %u, name \"%s\", namelen %u\n", slot, inodenum, nameptr, namelen);
#endif
/* copy filename and data in dirslot */
filldir(dirent, nameptr, namelen, filp->f_pos, inodenum);
brelse(bh);
/* store position of next slot */
if (++slot == numslots) {
slot = 0;
block++;
}
filp->f_pos = (block << EFS_BLOCKSIZE_BITS) | slot;
return 0;
}
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