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/*
* linux/fs/ufs/ufs_dir.c
*
* Copyright (C) 1996
* Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
* Laboratory for Computer Science Research Computing Facility
* Rutgers, The State University of New Jersey
*
* swab support by Francois-Rene Rideau <rideau@ens.fr> 19970406
*
*/
#include <linux/fs.h>
#include "ufs_swab.h"
/*
* This is blatantly stolen from ext2fs
*/
static int
ufs_readdir (struct file * filp, void * dirent, filldir_t filldir)
{
struct inode *inode = filp->f_dentry->d_inode;
int error = 0;
unsigned long offset, lblk, blk;
int i, stored;
struct buffer_head * bh;
struct ufs_direct * de;
struct super_block * sb;
int de_reclen;
__u32 s_flags, bytesex;
/* Isn't that already done but the upper layer??? */
if (!inode || !S_ISDIR(inode->i_mode))
return -EBADF;
sb = inode->i_sb;
s_flags = sb->u.ufs_sb.s_flags;
bytesex = s_flags & UFS_BYTESEX;
if (s_flags & UFS_DEBUG) {
printk("ufs_readdir: ino %lu f_pos %lu\n",
inode->i_ino, (unsigned long) filp->f_pos);
ufs_print_inode(inode);
}
stored = 0;
bh = NULL;
offset = filp->f_pos & (sb->s_blocksize - 1);
while (!error && !stored && filp->f_pos < inode->i_size) {
lblk = (filp->f_pos) >> sb->s_blocksize_bits;
/* XXX - ufs_bmap() call needs error checking */
blk = ufs_bmap(inode, lblk);
bh = bread (sb->s_dev, blk, sb->s_blocksize);
if (!bh) {
/* XXX - error - skip to the next block */
printk("ufs_readdir: "
"dir inode %lu has a hole at offset %lu\n",
inode->i_ino, (unsigned long int)filp->f_pos);
filp->f_pos += sb->s_blocksize - offset;
continue;
}
revalidate:
/* If the dir block has changed since the last call to
* readdir(2), then we might be pointing to an invalid
* dirent right now. Scan from the start of the block
* to make sure. */
if (filp->f_version != inode->i_version) {
for (i = 0; i < sb->s_blocksize && i < offset; ) {
de = (struct ufs_direct *)
(bh->b_data + i);
/* It's too expensive to do a full
* dirent test each time round this
* loop, but we do have to test at
* least that it is non-zero. A
* failure will be detected in the
* dirent test below. */
de_reclen = SWAB16(de->d_reclen);
if (de_reclen < 1)
break;
i += de_reclen;
}
offset = i;
filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
| offset;
filp->f_version = inode->i_version;
}
while (!error && filp->f_pos < inode->i_size
&& offset < sb->s_blocksize) {
de = (struct ufs_direct *) (bh->b_data + offset);
/* XXX - put in a real ufs_check_dir_entry() */
if ((de->d_reclen == 0) || (de->d_namlen == 0)) {
/* SWAB16() was unneeded -- compare to 0 */
filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1)) + sb->s_blocksize;
brelse(bh);
return stored;
}
#if 0
if (!ext2_check_dir_entry ("ext2_readdir", inode, de,
/* XXX - beware about de having to be swabped somehow */
bh, offset)) {
/* On error, skip the f_pos to the
next block. */
filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1))
+ sb->s_blocksize;
brelse (bh);
return stored;
}
#endif /* XXX */
offset += SWAB16(de->d_reclen);
if (de->d_ino) {
/* SWAB16() was unneeded -- compare to 0 */
/* We might block in the next section
* if the data destination is
* currently swapped out. So, use a
* version stamp to detect whether or
* not the directory has been modified
* during the copy operation. */
unsigned long version = inode->i_version;
if (s_flags & UFS_DEBUG) {
printk("ufs_readdir: filldir(%s,%u)\n",
de->d_name, SWAB32(de->d_ino));
}
error = filldir(dirent, de->d_name, SWAB16(de->d_namlen), filp->f_pos, SWAB32(de->d_ino));
if (error)
break;
if (version != inode->i_version)
goto revalidate;
stored ++;
}
filp->f_pos += SWAB16(de->d_reclen);
}
offset = 0;
brelse (bh);
}
#if 0 /* XXX */
if (!IS_RDONLY(inode)) {
inode->i_atime = CURRENT_TIME;
inode->i_dirt = 1;
}
#endif /* XXX */
return 0;
}
static struct file_operations ufs_dir_operations = {
NULL, /* lseek */
NULL, /* read */
NULL, /* write */
ufs_readdir, /* readdir */
NULL, /* select */
NULL, /* ioctl */
NULL, /* mmap */
NULL, /* open */
NULL, /* release */
file_fsync, /* fsync */
NULL, /* fasync */
NULL, /* check_media_change */
NULL, /* revalidate */
};
struct inode_operations ufs_dir_inode_operations = {
&ufs_dir_operations, /* default directory file operations */
NULL, /* create */
ufs_lookup, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
NULL, /* readlink */
NULL, /* readpage */
NULL, /* writepage */
NULL, /* bmap */
NULL, /* truncate */
NULL, /* permission */
NULL, /* smap */
};
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