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/*
* linux/fs/sysv/dir.c
*
* minix/dir.c
* Copyright (C) 1991, 1992 Linus Torvalds
*
* coh/dir.c
* Copyright (C) 1993 Pascal Haible, Bruno Haible
*
* sysv/dir.c
* Copyright (C) 1993 Bruno Haible
*
* SystemV/Coherent directory handling functions
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/sysv_fs.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <asm/uaccess.h>
static long sysv_dir_read(struct inode * inode, struct file * filp,
char * buf, unsigned long count)
{
return -EISDIR;
}
static int sysv_readdir(struct file *, void *, filldir_t);
static struct file_operations sysv_dir_operations = {
NULL, /* lseek - default */
sysv_dir_read, /* read */
NULL, /* write - bad */
sysv_readdir, /* readdir */
NULL, /* poll - default */
NULL, /* ioctl - default */
NULL, /* mmap */
NULL, /* no special open code */
NULL, /* no special release code */
file_fsync /* default fsync */
};
/*
* directories can handle most operations...
*/
struct inode_operations sysv_dir_inode_operations = {
&sysv_dir_operations, /* default directory file-ops */
sysv_create, /* create */
sysv_lookup, /* lookup */
sysv_link, /* link */
sysv_unlink, /* unlink */
sysv_symlink, /* symlink */
sysv_mkdir, /* mkdir */
sysv_rmdir, /* rmdir */
sysv_mknod, /* mknod */
sysv_rename, /* rename */
NULL, /* readlink */
NULL, /* follow_link */
NULL, /* readpage */
NULL, /* writepage */
NULL, /* bmap */
sysv_truncate, /* truncate */
NULL /* permission */
};
static int sysv_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
struct inode *inode = filp->f_dentry->d_inode;
struct super_block * sb;
unsigned int offset,i;
struct buffer_head * bh;
char* bh_data;
struct sysv_dir_entry * de, sde;
if (!inode || !(sb = inode->i_sb) || !S_ISDIR(inode->i_mode))
return -EBADF;
if ((unsigned long)(filp->f_pos) % SYSV_DIRSIZE)
return -EBADF;
while (filp->f_pos < inode->i_size) {
offset = filp->f_pos & sb->sv_block_size_1;
bh = sysv_file_bread(inode, filp->f_pos >> sb->sv_block_size_bits, 0);
if (!bh) {
filp->f_pos += sb->sv_block_size - offset;
continue;
}
bh_data = bh->b_data;
while (offset < sb->sv_block_size && filp->f_pos < inode->i_size) {
de = (struct sysv_dir_entry *) (offset + bh_data);
if (de->inode) {
/* Copy the directory entry first, because the directory
* might be modified while we sleep in filldir()...
*/
memcpy(&sde, de, sizeof(struct sysv_dir_entry));
if (sde.inode > inode->i_sb->sv_ninodes)
printk("sysv_readdir: Bad inode number on dev "
"%s, ino %ld, offset 0x%04lx: %d is out of range\n",
kdevname(inode->i_dev),
inode->i_ino, (off_t) filp->f_pos, sde.inode);
i = strnlen(sde.name, SYSV_NAMELEN);
if (filldir(dirent, sde.name, i, filp->f_pos, sde.inode) < 0) {
brelse(bh);
return 0;
}
}
offset += SYSV_DIRSIZE;
filp->f_pos += SYSV_DIRSIZE;
}
brelse(bh);
}
return 0;
}
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