/*
* modified for EXT2FS support in Lites 1.1
*
* Aug 1995, Godmar Back (gback@cs.utah.edu)
* University of Utah, Department of Computer Science
*/
/*
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)fs.h 8.7 (Berkeley) 4/19/94
* $FreeBSD$
*/
/*
* Each disk drive contains some number of file systems.
* A file system consists of a number of cylinder groups.
* Each cylinder group has inodes and data.
*
* A file system is described by its super-block, which in turn
* describes the cylinder groups. The super-block is critical
* data and is replicated in each cylinder group to protect against
* catastrophic loss. This is done at `newfs' time and the critical
* super-block data does not change, so the copies need not be
* referenced further unless disaster strikes.
*
* The first boot and super blocks are given in absolute disk addresses.
* The byte-offset forms are preferred, as they don't imply a sector size.
*/
#define SBSIZE 1024
#define SBLOCK 2
/*
* The path name on which the file system is mounted is maintained
* in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
* the super block for this name.
*/
#define MAXMNTLEN 512
/*
* Macros for access to superblock array structures
*/
/*
* Convert cylinder group to base address of its global summary info.
*/
#define fs_cs(fs, cgindx) (((struct ext2_group_desc *) \
(fs->s_group_desc[cgindx / EXT2_DESC_PER_BLOCK(fs)]->b_data)) \
[cgindx % EXT2_DESC_PER_BLOCK(fs)])
/*
* Turn file system block numbers into disk block addresses.
* This maps file system blocks to device size blocks.
*/
#define fsbtodb(fs, b) ((b) << ((fs)->s_fsbtodb))
#define dbtofsb(fs, b) ((b) >> ((fs)->s_fsbtodb))
/* get group containing inode */
#define ino_to_cg(fs, x) (((x) - 1) / EXT2_INODES_PER_GROUP(fs))
/* get block containing inode from its number x */
#define ino_to_fsba(fs, x) fs_cs(fs, ino_to_cg(fs, x)).bg_inode_table + \
(((x)-1) % EXT2_INODES_PER_GROUP(fs))/EXT2_INODES_PER_BLOCK(fs)
/* get offset for inode in block */
#define ino_to_fsbo(fs, x) ((x-1) % EXT2_INODES_PER_BLOCK(fs))
/*
* Give cylinder group number for a file system block.
* Give cylinder group block number for a file system block.
*/
#define dtog(fs, d) (((d) - fs->s_es->s_first_data_block) / \
EXT2_BLOCKS_PER_GROUP(fs))
#define dtogd(fs, d) (((d) - fs->s_es->s_first_data_block) % \
EXT2_BLOCKS_PER_GROUP(fs))
/*
* The following macros optimize certain frequently calculated
* quantities by using shifts and masks in place of divisions
* modulos and multiplications.
*/
#define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
((loc) & (fs)->s_qbmask)
#define lblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
((blk) << (fs->s_bshift))
#define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
((loc) >> (fs->s_bshift))
/* no fragments -> logical block number equal # of frags */
#define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
((loc) >> (fs->s_bshift))
#define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
roundup(size, fs->s_frag_size)
/* was (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask) */
/*
* Determining the size of a file block in the file system.
* easy w/o fragments
*/
#define blksize(fs, ip, lbn) ((fs)->s_frag_size)
/*
* INOPB is the number of inodes in a secondary storage block.
*/
#define INOPB(fs) EXT2_INODES_PER_BLOCK(fs)
/*
* NINDIR is the number of indirects in a file system block.
*/
#define NINDIR(fs) (EXT2_ADDR_PER_BLOCK(fs))
extern int inside[], around[];
extern u_char *fragtbl[];
/* a few remarks about superblock locking/unlocking
* Linux provides special routines for doing so
* I haven't figured out yet what BSD does
* I think I'll try a VOP_LOCK/VOP_UNLOCK on the device vnode
*/
#define DEVVP(inode) (VFSTOEXT2(ITOV(inode)->v_mount)->um_devvp)
#define lock_super(devvp) vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, curthread)
#define unlock_super(devvp) VOP_UNLOCK(devvp, 0, curthread)
/*
* To lock a buffer, set the B_LOCKED flag and then brelse() it. To unlock,
* reset the B_LOCKED flag and brelse() the buffer back on the LRU list
*/
#define LCK_BUF(bp) BUF_KERNPROC(bp);
#define ULCK_BUF(bp) { \
long flags; \
int s; \
s = splbio(); \
flags = (bp)->b_flags; \
(bp)->b_flags &= ~(B_DIRTY); \
splx(s); \
if (flags & B_DIRTY) \
bwrite(bp); \
else \
brelse(bp); \
}
