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/*
* dir.c
*
* Copyright (c) 1999 Al Smith
*/
#include <linux/buffer_head.h>
#include <linux/smp_lock.h>
#include "efs.h"
static int efs_readdir(struct file *, void *, filldir_t);
const struct file_operations efs_dir_operations = {
.read = generic_read_dir,
.readdir = efs_readdir,
};
const struct inode_operations efs_dir_inode_operations = {
.lookup = efs_lookup,
};
static int efs_readdir(struct file *filp, void *dirent, filldir_t filldir) {
struct inode *inode = filp->f_path.dentry->d_inode;
struct buffer_head *bh;
struct efs_dir *dirblock;
struct efs_dentry *dirslot;
efs_ino_t inodenum;
efs_block_t block;
int slot, namelen;
char *nameptr;
if (inode->i_size & (EFS_DIRBSIZE-1))
printk(KERN_WARNING "EFS: WARNING: readdir(): directory size not a multiple of EFS_DIRBSIZE\n");
lock_kernel();
/* work out where this entry can be found */
block = filp->f_pos >> EFS_DIRBSIZE_BITS;
/* each block contains at most 256 slots */
slot = filp->f_pos & 0xff;
/* look at all blocks */
while (block < inode->i_blocks) {
/* read the dir block */
bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
if (!bh) {
printk(KERN_ERR "EFS: readdir(): failed to read dir block %d\n", block);
break;
}
dirblock = (struct efs_dir *) bh->b_data;
if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
printk(KERN_ERR "EFS: readdir(): invalid directory block\n");
brelse(bh);
break;
}
while (slot < dirblock->slots) {
if (dirblock->space[slot] == 0) {
slot++;
continue;
}
dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
inodenum = be32_to_cpu(dirslot->inode);
namelen = dirslot->namelen;
nameptr = dirslot->name;
#ifdef DEBUG
printk(KERN_DEBUG "EFS: readdir(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", block, slot, dirblock->slots-1, inodenum, nameptr, namelen);
#endif
if (namelen > 0) {
/* found the next entry */
filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
/* copy filename and data in dirslot */
filldir(dirent, nameptr, namelen, filp->f_pos, inodenum, DT_UNKNOWN);
/* sanity check */
if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
printk(KERN_WARNING "EFS: directory entry %d exceeds directory block\n", slot);
slot++;
continue;
}
/* store position of next slot */
if (++slot == dirblock->slots) {
slot = 0;
block++;
}
brelse(bh);
filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
goto out;
}
slot++;
}
brelse(bh);
slot = 0;
block++;
}
filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;
out:
unlock_kernel();
return 0;
}
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