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/*
* linux/fs/ufs/ufs_namei.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
*
* Clean swab support by Francois-Rene Rideau <rideau@ens.fr> 19970406
* Ported to 2.1.62 by Francois-Rene Rideau <rideau@ens.fr> 19971109
*
* 4.4BSD (FreeBSD) support added on February 1st 1998 by
* Niels Kristian Bech Jensen <nkbj@image.dk> partially based
* on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
*/
#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include <linux/string.h>
#include "ufs_swab.h"
/*
* NOTE1: unlike strncmp, ufs_match returns 1 for success, 0 for failure
* (stolen from ext2fs.)
* NOTE2: flags *is* used, though this is hidden by macros like NAMLEN.
*/
static int ufs_match (int len, const char * const name, struct ufs_direct * d, __u32 flags)
{
if (!d || len > UFS_MAXNAMLEN) /* XXX - name space */
return 0;
/*
* "" means "." ---> so paths like "/usr/lib//libc.a" work
*/
if (!len && (NAMLEN(d) == 1) && (d->d_name[0] == '.') &&
(d->d_name[1] == '\0'))
return 1;
if (len != NAMLEN(d))
return 0;
return !memcmp(name, d->d_name, len);
}
int ufs_lookup (struct inode *dir, struct dentry *dentry)
{
/* XXX - this is all fucked up! */
unsigned long int lfragno, fragno;
struct buffer_head * bh;
struct ufs_direct * d;
struct super_block * sb = dir->i_sb;
const char *name = dentry->d_name.name;
int len = dentry->d_name.len;
__u32 flags;
struct inode *inode;
/* XXX - isn't that already done by the upper layer? */
if (!dir || !S_ISDIR(dir->i_mode))
return -EBADF;
flags = sb->u.ufs_sb.s_flags;
if (flags & UFS_DEBUG)
printk("Passed name: %s\nPassed length: %d\n", name, len);
/* debugging hacks:
* Touching /xyzzy in a filesystem toggles debugging messages.
*/
if ((len == 5) && !(memcmp(name, "xyzzy", len)) &&
(dir->i_ino == UFS_ROOTINO)) {
sb->u.ufs_sb.s_flags ^= UFS_DEBUG;
printk("UFS debugging %s\n",
(sb->u.ufs_sb.s_flags & UFS_DEBUG) ?
"on": "off");
goto not_found;
/*return(-ENOENT);*/
}
/*
* Touching /xyzzy.i in a filesystem toggles debugging for ufs_inode.c
*/
if ((len == 7) && !(memcmp(name, "xyzzy.i", len)) &&
(dir->i_ino == UFS_ROOTINO)) {
sb->u.ufs_sb.s_flags ^= UFS_DEBUG_INODE;
printk("UFS inode debugging %s\n",
(sb->u.ufs_sb.s_flags & UFS_DEBUG_INODE) ?
"on": "off");
goto not_found;
/*return(-ENOENT);*/
}
/*
* Touching /xyzzy.n in a filesystem toggles debugging for ufs_namei.c
*/
if ((len == 7) && !(memcmp(name, "xyzzy.n", len)) &&
(dir->i_ino == UFS_ROOTINO)) {
sb->u.ufs_sb.s_flags ^= UFS_DEBUG_NAMEI;
printk("UFS namei debugging %s\n",
(sb->u.ufs_sb.s_flags & UFS_DEBUG_NAMEI) ?
"on": "off");
goto not_found;
/*return(-ENOENT);*/
}
/*
* Touching /xyzzy.l in a filesystem toggles debugging for ufs_symlink.c
*/
if ((len == 7) && !(memcmp(name, "xyzzy.l", len)) &&
(dir->i_ino == UFS_ROOTINO)) {
sb->u.ufs_sb.s_flags ^= UFS_DEBUG_LINKS;
printk("UFS symlink debugging %s\n",
(sb->u.ufs_sb.s_flags & UFS_DEBUG_LINKS) ?
"on": "off");
goto not_found;
/*return(-ENOENT);*/
}
/* Now for the real thing */
if (flags & (UFS_DEBUG|UFS_DEBUG_NAMEI)) {
printk("ufs_lookup: called for ino %lu name %s\n",
dir->i_ino, name);
}
for (lfragno = 0; lfragno < dir->i_blocks; lfragno++) {
fragno = ufs_bmap(dir, lfragno);
/* ufs_bmap() reads the block (frag) size in s_blocksize */
/* XXX - ufs_bmap() call needs error checking */
if (flags & UFS_DEBUG) {
printk("ufs_lookup: ino %lu lfragno %lu fragno %lu\n",
dir->i_ino, lfragno, fragno);
}
if (fragno == 0) {
/* XXX - bug bug bug */
goto not_found;
/*return(-ENOENT);*/
}
bh = bread(dir->i_dev, fragno, sb->s_blocksize);
if (bh == NULL) {
printk("ufs_lookup: bread failed: "
"ino %lu, lfragno %lu",
dir->i_ino, lfragno);
return(-EIO);
}
d = (struct ufs_direct *)(bh->b_data);
while (((char *)d - bh->b_data + SWAB16(d->d_reclen)) <=
sb->s_blocksize) {
/* XXX - skip block if d_reclen or d_namlen is 0 */
if ((d->d_reclen == 0) || (NAMLEN(d) == 0)) {
/* no need to SWAB16(): test against 0 */
if (flags & UFS_DEBUG) {
printk("ufs_lookup: skipped space in directory, ino %lu\n",
dir->i_ino);
}
break;
}
if (flags & UFS_DEBUG) {
printk("lfragno 0x%lx "
"direct d 0x%x "
"d_ino %u "
"d_reclen %u "
"d_namlen %u d_name `%s'\n",
lfragno,
(unsigned int)((unsigned long)d),
SWAB32(d->d_ino),
SWAB16(d->d_reclen),
NAMLEN(d),d->d_name);
}
if ((NAMLEN(d) == len) &&
/* XXX - don't use strncmp() - see ext2fs */
(ufs_match(len, name, d, flags))) {
/* We have a match */
/* XXX - I only superficially understand how things work,
* so use at your own risk... -- Fare'
*/
inode = iget(sb, SWAB32(d->d_ino));
brelse(bh);
if(!inode) { return -EACCES; }
d_add(dentry,inode);
return(0);
} else {
/* XXX - bounds checking */
if (flags & UFS_DEBUG) {
printk("ufs_lookup: "
"wanted (%s,%d) got (%s,%d)\n",
name, len,
d->d_name, NAMLEN(d));
}
}
d = (struct ufs_direct *)((char *)d +
SWAB16(d->d_reclen));
}
brelse(bh);
}
not_found:
d_add(dentry,NULL);
return(0);
}
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