freebsd-nq/sys/fs/ext2fs/ext2_subr.c
Pedro F. Giffuni 70097aac13 Define ext2fs local types and use them.
Add definitions for e2fs_daddr_t, e4fs_daddr_t in addition
to the already existing e2fs_lbn_t and adjust them for ext4.
Other than making the code more readable these changes should
fix problems related to big filesystems.

Setting the proper types can be tricky so the process was
helped by looking at UFS. In our implementation, logical block
numbers can be negative and the code depends on it. In ext2,
block numbers are unsigned so it is convenient to keep
e2fs_daddr_t unsigned and use the complete 32 bits. In the
case of e4fs_daddr_t, while the value should be unsigned, for
ext4 we only need to support 48 bits so preserving an extra
bit from the sign is not an issue.

While here also drop the ext2_setblock() prototype that was
never used.

Discussed with:	mckusick, bde
MFC after:	3 weeks
2013-08-13 15:40:43 +00:00

264 lines
6.6 KiB
C

/*-
* modified for Lites 1.1
*
* Aug 1995, Godmar Back (gback@cs.utah.edu)
* University of Utah, Department of Computer Science
*/
/*-
* 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.
* 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.
*
* @(#)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/ext2_extern.h>
#include <fs/ext2fs/ext2fs.h>
#include <fs/ext2fs/fs.h>
#include <fs/ext2fs/ext2_extents.h>
#include <fs/ext2fs/ext2_mount.h>
#include <fs/ext2fs/ext2_dinode.h>
#ifdef KDB
void ext2_checkoverlap(struct buf *, struct inode *);
#endif
/*
* 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 bsize, error;
daddr_t newblk;
struct ext4_extent *ep;
struct ext4_extent_path path;
ip = VTOI(vp);
fs = ip->i_e2fs;
lbn = lblkno(fs, offset);
bsize = blksize(fs, ip, lbn);
*bpp = NULL;
/*
* The EXT4_EXTENTS requires special treatment, otherwise we can
* fall back to the normal path.
*/
if (!(ip->i_flags & EXT4_EXTENTS))
goto normal;
memset(&path, 0, sizeof(path));
if (ext4_ext_find_extent(fs, ip, lbn, &path) == NULL)
goto normal;
ep = path.ep_ext;
if (ep == NULL)
goto normal;
newblk = lbn - ep->e_blk +
(ep->e_start_lo | (daddr_t)ep->e_start_hi << 32);
if (path.ep_bp != NULL) {
brelse(path.ep_bp);
path.ep_bp = NULL;
}
error = bread(ip->i_devvp, fsbtodb(fs, newblk), bsize, NOCRED, &bp);
if (error != 0) {
brelse(bp);
return (error);
}
if (res)
*res = (char *)bp->b_data + blkoff(fs, offset);
/*
* If EXT4_EXTENTS is enabled we would get a wrong offset so
* reset b_offset here.
*/
bp->b_offset = lbn * bsize;
*bpp = bp;
return (0);
normal:
if (*bpp == NULL) {
if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
brelse(bp);
return (error);
}
if (res)
*res = (char *)bp->b_data + blkoff(fs, offset);
*bpp = bp;
}
return (0);
}
#ifdef KDB
void
ext2_checkoverlap(struct buf *bp, struct inode *ip)
{
struct buf *ebp, *ep;
e4fs_daddr_t start, last;
struct vnode *vp;
ebp = &buf[nbuf];
start = bp->b_blkno;
last = start + btodb(bp->b_bcount) - 1;
for (ep = buf; ep < ebp; ep++) {
if (ep == bp || (ep->b_flags & B_INVAL))
continue;
vp = ip->i_ump->um_devvp;
/* look for overlap */
if (ep->b_bcount == 0 || ep->b_blkno > last ||
ep->b_blkno + btodb(ep->b_bcount) <= start)
continue;
vprint("Disk overlap", vp);
(void)printf("\tstart %d, end %d overlap start %lld, end %ld\n",
start, last, (long long)ep->b_blkno,
(long)(ep->b_blkno + btodb(ep->b_bcount) - 1));
panic("Disk buffer overlap");
}
}
#endif /* KDB */
/*
* 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, daddr_t bno, int cnt)
{
int32_t *sump = fs->e2fs_clustersum[cg].cs_sum;
int32_t *lp;
int back, bit, end, forw, i, loc, start;
/* 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;
}