freebsd-skq/sys/fs/ext2fs/ext2_subr.c
fsu 1c4853adf6 Add metadata_csum feature support.
Reviewed by:   pfg (mentor)
Approved by:   pfg (mentor)
MFC after:     6 months

Differential Revision:    https://reviews.freebsd.org/D13810
2018-01-14 20:46:39 +00:00

200 lines
5.1 KiB
C

/*-
* modified for Lites 1.1
*
* Aug 1995, Godmar Back (gback@cs.utah.edu)
* University of Utah, Department of Computer Science
*/
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1989, 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. 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.
*
* @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/lock.h>
#include <sys/ucred.h>
#include <sys/vnode.h>
#include <fs/ext2fs/inode.h>
#include <fs/ext2fs/ext2fs.h>
#include <fs/ext2fs/ext2_extern.h>
#include <fs/ext2fs/fs.h>
#include <fs/ext2fs/ext2_extents.h>
#include <fs/ext2fs/ext2_mount.h>
#include <fs/ext2fs/ext2_dinode.h>
/*
* Return buffer with the contents of block "offset" from the beginning of
* directory "ip". If "res" is non-zero, fill it in with a pointer to the
* remaining space in the directory.
*/
int
ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
{
struct inode *ip;
struct m_ext2fs *fs;
struct buf *bp;
e2fs_lbn_t lbn;
int error, bsize;
ip = VTOI(vp);
fs = ip->i_e2fs;
lbn = lblkno(fs, offset);
bsize = blksize(fs, ip, lbn);
if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
brelse(bp);
return (error);
}
error = ext2_dir_blk_csum_verify(ip, bp);
if (error != 0) {
brelse(bp);
return (error);
}
if (res)
*res = (char *)bp->b_data + blkoff(fs, offset);
*bpp = bp;
return (0);
}
/*
* Update the cluster map because of an allocation of free like ffs.
*
* Cnt == 1 means free; cnt == -1 means allocating.
*/
void
ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, e4fs_daddr_t bno, int cnt)
{
int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
int32_t *lp;
e4fs_daddr_t start, end, loc, forw, back;
int bit, i;
/* Initialize the cluster summary array. */
if (fs->e2fs_clustersum[cg].cs_init == 0) {
int run = 0;
bit = 1;
loc = 0;
for (i = 0; i < fs->e2fs->e2fs_fpg; i++) {
if ((bbp[loc] & bit) == 0)
run++;
else if (run != 0) {
if (run > fs->e2fs_contigsumsize)
run = fs->e2fs_contigsumsize;
sump[run]++;
run = 0;
}
if ((i & (NBBY - 1)) != (NBBY - 1))
bit <<= 1;
else {
loc++;
bit = 1;
}
}
if (run != 0) {
if (run > fs->e2fs_contigsumsize)
run = fs->e2fs_contigsumsize;
sump[run]++;
}
fs->e2fs_clustersum[cg].cs_init = 1;
}
if (fs->e2fs_contigsumsize <= 0)
return;
/* Find the size of the cluster going forward. */
start = bno + 1;
end = start + fs->e2fs_contigsumsize;
if (end > fs->e2fs->e2fs_fpg)
end = fs->e2fs->e2fs_fpg;
loc = start / NBBY;
bit = 1 << (start % NBBY);
for (i = start; i < end; i++) {
if ((bbp[loc] & bit) != 0)
break;
if ((i & (NBBY - 1)) != (NBBY - 1))
bit <<= 1;
else {
loc++;
bit = 1;
}
}
forw = i - start;
/* Find the size of the cluster going backward. */
start = bno - 1;
end = start - fs->e2fs_contigsumsize;
if (end < 0)
end = -1;
loc = start / NBBY;
bit = 1 << (start % NBBY);
for (i = start; i > end; i--) {
if ((bbp[loc] & bit) != 0)
break;
if ((i & (NBBY - 1)) != 0)
bit >>= 1;
else {
loc--;
bit = 1 << (NBBY - 1);
}
}
back = start - i;
/*
* Account for old cluster and the possibly new forward and
* back clusters.
*/
i = back + forw + 1;
if (i > fs->e2fs_contigsumsize)
i = fs->e2fs_contigsumsize;
sump[i] += cnt;
if (back > 0)
sump[back] -= cnt;
if (forw > 0)
sump[forw] -= cnt;
/* Update cluster summary information. */
lp = &sump[fs->e2fs_contigsumsize];
for (i = fs->e2fs_contigsumsize; i > 0; i--)
if (*lp-- > 0)
break;
fs->e2fs_maxcluster[cg] = i;
}