/* $NetBSD: readufs_lfs.c,v 1.3 2015/08/20 07:50:08 christos Exp $ */

/* $NetBSD: readufs_lfs.c,v 1.3 2015/08/20 07:50:08 christos Exp $ */
/* from Id: readufs_lfs.c,v 1.8 2003/12/16 13:54:11 itohy Exp */

/*
* FS specific support for 4.4BSD Log-structured Filesystem
*
* Written in 1999, 2002, 2003 by ITOH Yasufumi.
* Public domain.
*
* Intended to be used for boot programs (first stage).
* DON'T ADD ANY FANCY FEATURE. THIS SHALL BE COMPACT.
*/

#include "readufs.h"

#include <sys/mount.h>
#include <ufs/lfs/lfs.h>

#ifndef USE_UFS1
#error LFS currently requires USE_UFS1
#endif

static struct lfs32_dinode ifile_dinode;

#define fsi (*ufsinfo)
#define fsi_lfs fsi.fs_u.u_lfs

/*
* Read and check superblock.
* If it is an LFS, save information from the superblock.
*/
int
try_lfs(void)
{
struct ufs_info *ufsinfo = &ufs_info;
struct dlfs sblk, sblk2;
struct dlfs *s = &sblk;
daddr_t sbpos;
int fsbshift;

#ifdef DEBUG_WITH_STDIO
printf("trying LFS\n");
#endif
sbpos = btodb(LFS_LABELPAD);

/* read primary superblock */
for (;;) {
#ifdef DEBUG_WITH_STDIO
printf("LFS: reading primary sblk at: 0x%x\n", (unsigned)sbpos);
#endif
RAW_READ(&sblk, sbpos, sizeof sblk);

#ifdef DEBUG_WITH_STDIO
printf("LFS: sblk: magic: 0x%x, version: %d\n",
sblk.dlfs_magic, sblk.dlfs_version);
#endif

if (sblk.dlfs_magic != LFS_MAGIC)
return 1;

#ifdef DEBUG_WITH_STDIO
printf("LFS: bsize %d, fsize %d, bshift %d, blktodb %d, fsbtodb %d, inopf %d, inopb %d\n",
sblk.dlfs_bsize, sblk.dlfs_fsize,
sblk.dlfs_bshift, sblk.dlfs_blktodb, sblk.dlfs_fsbtodb,
sblk.dlfs_inopf, sblk.dlfs_inopb);
#endif
if ((fsi_lfs.version = sblk.dlfs_version) == 1) {
fsbshift = 0;
break;
} else {
daddr_t sbpos1;
#if 0
fsbshift = sblk.dlfs_bshift - sblk.dlfs_blktodb + sblk.dlfs_fsbtodb - DEV_BSHIFT;
#endif
fsbshift = sblk.dlfs_fsbtodb;
sbpos1 = sblk.dlfs_sboffs[0] << fsbshift;
if (sbpos == sbpos1)
break;
#ifdef DEBUG_WITH_STDIO
printf("LFS: correcting primary sblk location\n");
#endif
sbpos = sbpos1;
}
}

#ifdef DEBUG_WITH_STDIO
printf("fsbshift: %d\n", fsbshift);
printf("sboff[1]: %d\n", sblk.dlfs_sboffs[1]);
#endif

if (sblk.dlfs_sboffs[1] > 0) {
#ifdef DEBUG_WITH_STDIO
printf("LFS: reading secondary sblk at: 0x%x\n",
sblk.dlfs_sboffs[1] << fsbshift);
#endif
/* read secondary superblock */
RAW_READ(&sblk2, (daddr_t) sblk.dlfs_sboffs[1] << fsbshift,
sizeof sblk2);

#ifdef DEBUG_WITH_STDIO
printf("LFS: sblk2: magic: 0x%x, version: %d\n",
sblk2.dlfs_magic, sblk2.dlfs_version);
#endif

if (sblk2.dlfs_magic == LFS_MAGIC) {
if (fsi_lfs.version == 1) {
if (sblk.dlfs_inopf > sblk2.dlfs_inopf)
s = &sblk2;
} else {
if (sblk.dlfs_serial > sblk2.dlfs_serial)
s = &sblk2;
}
}
}

/* This partition looks like an LFS. */
#if 0
fsi.get_inode = get_lfs_inode;
#endif
/*
* version 1: disk addr is in disk sector --- no shifting
* version 2: disk addr is in fragment
*/
fsi.fsbtodb = fsbshift;

/* Get information from the superblock. */
fsi.bsize = s->dlfs_bsize;
fsi.nindir = s->dlfs_nindir;
fsi_lfs.idaddr = s->dlfs_idaddr;
fsi_lfs.ibsize = (fsi_lfs.version == 1) ? s->dlfs_bsize : s->dlfs_fsize;

/*
* version 1: number of inode per block
* version 2: number of inode per fragment (but in dlfs_inopb)
*/
fsi_lfs.inopb = s->dlfs_inopb;

fsi_lfs.ifpb = s->dlfs_ifpb;
fsi_lfs.ioffset = s->dlfs_cleansz + s->dlfs_segtabsz;

/* ifile is always used to look-up other inodes, so keep its inode. */
if (get_lfs_inode(LFS_IFILE_INUM, (union ufs_dinode *)&ifile_dinode))
return 1; /* OOPS, failed to find inode of ifile! */

fsi.fstype = UFSTYPE_LFS;

return 0;
}

/*
* Get inode from disk.
*/
int
get_lfs_inode(ino32_t ino, union ufs_dinode *dibuf)
{
struct ufs_info *ufsinfo = &ufs_info;
daddr_t daddr;
char *buf = alloca(fsi.bsize);
struct lfs32_dinode *di, *diend;
int i;

/* Get fs block which contains the specified inode. */
if (ino == LFS_IFILE_INUM)
daddr = fsi_lfs.idaddr;
else {
#ifdef DEBUG_WITH_STDIO
printf("LFS: ino: %d\nifpb: %d, bsize: %d\n",
ino, fsi_lfs.ifpb, fsi.bsize);
#endif
ufs_read((union ufs_dinode *) &ifile_dinode, buf,
ino / fsi_lfs.ifpb + fsi_lfs.ioffset,
fsi.bsize);
i = ino % fsi_lfs.ifpb;
daddr = (fsi_lfs.version == 1) ?
((IFILE_V1 *) buf + i)->if_daddr
: ((IFILE32 *) buf + i)->if_daddr;
}
#ifdef DEBUG_WITH_STDIO
printf("LFS(%d): daddr: %d\n", ino, (int) daddr);
#endif

if (daddr == LFS_UNUSED_DADDR)
return 1;

/* Read the inode block. */
RAW_READ(buf, daddr << fsi.fsbtodb, fsi_lfs.ibsize);

/* Search for the inode. */
di = (struct lfs32_dinode *) buf;
diend = di + fsi_lfs.inopb;

for ( ; di < diend; di++)
if (di->di_inumber == ino)
goto found;
/* not found */
return 1;

found:
#ifdef DEBUG_WITH_STDIO
printf("LFS: dinode(%d): mode 0%o, nlink %d, inumber %d, size %d, uid %d, db[0] %d\n",
ino, di->di_mode, di->di_nlink, di->di_inumber,
(int) di->di_size, di->di_uid, di->di_db[0]);
#endif

#if 0 /* currently UFS1 only */
#if defined(USE_UFS1) && defined(USE_UFS2)
/* XXX for DI_SIZE() macro */
if (ufsinfo->ufstype != UFSTYPE_UFS1)
di->di1.di_size = di->si2.di_size;
#endif
#endif

dibuf->dil32 = *di;

return 0;
}