111 lines
2.4 KiB
C
111 lines
2.4 KiB
C
/* from Id: readufs_ffs.c,v 1.5 2002/01/26 16:26:44 itohy Exp */
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/*
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* FS specific support for 4.2BSD Fast Filesystem
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*
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* Written by ITOH, Yasufumi (itohy@netbsd.org).
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* Public domain.
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*
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* Intended to be used for boot programs (first stage).
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* DON'T ADD ANY FANCY FEATURE. THIS SHALL BE COMPACT.
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*/
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#include <sys/types.h>
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#include <sys/param.h>
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#include <ufs/ufs/dinode.h>
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#include <ufs/ffs/fs.h>
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#include "readufs.h"
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static int get_ffs_inode __P((ino_t ino, struct dinode *dibuf));
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#define fsi (*ufsinfo)
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#define fsi_ffs fsi.fs_u.u_ffs
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/*
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* Read and check superblock.
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* If it is an FFS, save information from the superblock.
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*/
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int
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try_ffs()
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{
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union {
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struct fs sblk;
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unsigned char pad[SBSIZE];
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} buf;
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struct ufs_info *ufsinfo = &ufs_info;
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#ifdef DEBUG_WITH_STDIO
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printf("trying FFS\n");
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#endif
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/* read FFS superblock */
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RAW_READ(&buf, SBLOCK, SBSIZE);
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#ifdef DEBUG_WITH_STDIO
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printf("FFS: sblk: magic: 0x%x\n", buf.sblk.fs_magic);
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#endif
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if (buf.sblk.fs_magic != FS_MAGIC)
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return 1;
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/* This partition looks like an FFS. */
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fsi.fstype = UFSTYPE_FFS;
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fsi.get_inode = get_ffs_inode;
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/* Get information from the superblock. */
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fsi.bsize = buf.sblk.fs_bsize;
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fsi.fsbtodb = buf.sblk.fs_fsbtodb;
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fsi.nindir = buf.sblk.fs_nindir;
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fsi_ffs.iblkno = buf.sblk.fs_iblkno;
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fsi_ffs.cgoffset = buf.sblk.fs_cgoffset;
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fsi_ffs.cgmask = buf.sblk.fs_cgmask;
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fsi_ffs.fragshift = buf.sblk.fs_fragshift;
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fsi_ffs.inopb = buf.sblk.fs_inopb;
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fsi_ffs.ipg = buf.sblk.fs_ipg;
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fsi_ffs.fpg = buf.sblk.fs_fpg;
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return 0;
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}
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/* for inode macros */
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#define fs_ipg fs_u.u_ffs.ipg
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#define fs_iblkno fs_u.u_ffs.iblkno
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#define fs_cgoffset fs_u.u_ffs.cgoffset
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#define fs_cgmask fs_u.u_ffs.cgmask
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#define fs_fpg fs_u.u_ffs.fpg
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#define fs_inopb fs_u.u_ffs.inopb
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#define fs_fragshift fs_u.u_ffs.fragshift
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#define fs_fsbtodb fsbtodb
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/*
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* Get inode from disk.
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*/
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static int
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get_ffs_inode(ino, dibuf)
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ino_t ino;
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struct dinode *dibuf;
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{
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struct ufs_info *ufsinfo = &ufs_info;
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struct dinode *buf = alloca((size_t) fsi.bsize);
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struct dinode *di;
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RAW_READ(buf, fsbtodb(&fsi, ino_to_fsba(&fsi, ino)),
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(size_t) fsi.bsize);
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di = &buf[ino_to_fsbo(&fsi, ino)];
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#ifdef DEBUG_WITH_STDIO
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printf("FFS: dinode(%d): mode 0%o, nlink %d, size %d, uid %d, gid %d, db[0] %d\n",
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ino, di->di_mode, di->di_nlink, (int)di->di_size,
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di->di_uid, di->di_gid, di->di_db[0]);
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#endif
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if (di->di_mode == 0)
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return 1; /* unused inode (file is not found) */
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*dibuf = *di;
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return 0;
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}
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