NetBSD/sys/ufs/ffs/ffs_subr.c
pk 70f20a1217 Replace the traditional buffer memory management -- based on fixed per buffer
virtual memory reservation and a private pool of memory pages -- by a scheme
based on memory pools.

This allows better utilization of memory because buffers can now be allocated
with a granularity finer than the system's native page size (useful for
filesystems with e.g. 1k or 2k fragment sizes).  It also avoids fragmentation
of virtual to physical memory mappings (due to the former fixed virtual
address reservation) resulting in better utilization of MMU resources on some
platforms.  Finally, the scheme is more flexible by allowing run-time decisions
on the amount of memory to be used for buffers.

On the other hand, the effectiveness of the LRU queue for buffer recycling
may be somewhat reduced compared to the traditional method since, due to the
nature of the pool based memory allocation, the actual least recently used
buffer may release its memory to a pool different from the one needed by a
newly allocated buffer. However, this effect will kick in only if the
system is under memory pressure.
2003-12-30 12:33:13 +00:00

352 lines
8.3 KiB
C

/* $NetBSD: ffs_subr.c,v 1.32 2003/12/30 12:33:24 pk Exp $ */
/*
* 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 8.5 (Berkeley) 3/21/95
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ffs_subr.c,v 1.32 2003/12/30 12:33:24 pk Exp $");
#include <sys/param.h>
/* in ffs_tables.c */
extern const int inside[], around[];
extern const u_char * const fragtbl[];
#ifndef _KERNEL
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
#include <ufs/ufs/ufs_bswap.h>
void panic __P((const char *, ...))
__attribute__((__noreturn__,__format__(__printf__,1,2)));
#else /* _KERNEL */
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/inttypes.h>
#include <sys/pool.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
#include <ufs/ufs/ufs_bswap.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
ffs_blkatoff(v)
void *v;
{
struct vop_blkatoff_args /* {
struct vnode *a_vp;
off_t a_offset;
char **a_res;
struct buf **a_bpp;
} */ *ap = v;
struct inode *ip;
struct fs *fs;
struct buf *bp;
daddr_t lbn;
int bsize, error;
ip = VTOI(ap->a_vp);
fs = ip->i_fs;
lbn = lblkno(fs, ap->a_offset);
bsize = blksize(fs, ip, lbn);
*ap->a_bpp = NULL;
if ((error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) != 0) {
brelse(bp);
return (error);
}
if (ap->a_res)
*ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset);
*ap->a_bpp = bp;
return (0);
}
/*
* Load up the contents of an inode and copy the appropriate pieces
* to the incore copy.
*/
void
ffs_load_inode(bp, ip, fs, ino)
struct buf *bp;
struct inode *ip;
struct fs *fs;
ino_t ino;
{
struct ufs1_dinode *dp1;
struct ufs2_dinode *dp2;
if (ip->i_ump->um_fstype == UFS1) {
dp1 = (struct ufs1_dinode *)bp->b_data + ino_to_fsbo(fs, ino);
#ifdef FFS_EI
if (UFS_FSNEEDSWAP(fs))
ffs_dinode1_swap(dp1, ip->i_din.ffs1_din);
else
#endif
*ip->i_din.ffs1_din = *dp1;
ip->i_mode = ip->i_ffs1_mode;
ip->i_nlink = ip->i_ffs1_nlink;
ip->i_size = ip->i_ffs1_size;
ip->i_flags = ip->i_ffs1_flags;
ip->i_gen = ip->i_ffs1_gen;
ip->i_uid = ip->i_ffs1_uid;
ip->i_gid = ip->i_ffs1_gid;
} else {
dp2 = (struct ufs2_dinode *)bp->b_data + ino_to_fsbo(fs, ino);
#ifdef FFS_EI
if (UFS_FSNEEDSWAP(fs))
ffs_dinode2_swap(dp2, ip->i_din.ffs2_din);
else
#endif
*ip->i_din.ffs2_din = *dp2;
ip->i_mode = ip->i_ffs2_mode;
ip->i_nlink = ip->i_ffs2_nlink;
ip->i_size = ip->i_ffs2_size;
ip->i_flags = ip->i_ffs2_flags;
ip->i_gen = ip->i_ffs2_gen;
ip->i_uid = ip->i_ffs2_uid;
ip->i_gid = ip->i_ffs2_gid;
}
}
#endif /* _KERNEL */
/*
* Update the frsum fields to reflect addition or deletion
* of some frags.
*/
void
ffs_fragacct(fs, fragmap, fraglist, cnt, needswap)
struct fs *fs;
int fragmap;
int32_t fraglist[];
int cnt;
int needswap;
{
int inblk;
int field, subfield;
int siz, pos;
inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
fragmap <<= 1;
for (siz = 1; siz < fs->fs_frag; siz++) {
if ((inblk & (1 << (siz + (fs->fs_frag & (NBBY - 1))))) == 0)
continue;
field = around[siz];
subfield = inside[siz];
for (pos = siz; pos <= fs->fs_frag; pos++) {
if ((fragmap & field) == subfield) {
fraglist[siz] = ufs_rw32(
ufs_rw32(fraglist[siz], needswap) + cnt,
needswap);
pos += siz;
field <<= siz;
subfield <<= siz;
}
field <<= 1;
subfield <<= 1;
}
}
}
#if defined(_KERNEL) && defined(DIAGNOSTIC)
void
ffs_checkoverlap(bp, ip)
struct buf *bp;
struct inode *ip;
{
#if 0
struct buf *ebp, *ep;
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) ||
ep->b_vp == NULLVP)
continue;
if (VOP_BMAP(ep->b_vp, (daddr_t)0, &vp, (daddr_t)0, NULL))
continue;
if (vp != ip->i_devvp)
continue;
/* 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);
printf("\tstart %" PRId64 ", end %" PRId64 " overlap start "
"%" PRId64 ", end %" PRId64 "\n",
start, last, ep->b_blkno,
ep->b_blkno + btodb(ep->b_bcount) - 1);
panic("Disk buffer overlap");
}
#else
printf("ffs_checkoverlap disabled due to buffer cache implementation changes\n");
#endif
}
#endif /* _KERNEL && DIAGNOSTIC */
/*
* block operations
*
* check if a block is available
* returns true if all the correponding bits in the free map are 1
* returns false if any corresponding bit in the free map is 0
*/
int
ffs_isblock(fs, cp, h)
struct fs *fs;
u_char *cp;
int32_t h;
{
u_char mask;
switch ((int)fs->fs_fragshift) {
case 3:
return (cp[h] == 0xff);
case 2:
mask = 0x0f << ((h & 0x1) << 2);
return ((cp[h >> 1] & mask) == mask);
case 1:
mask = 0x03 << ((h & 0x3) << 1);
return ((cp[h >> 2] & mask) == mask);
case 0:
mask = 0x01 << (h & 0x7);
return ((cp[h >> 3] & mask) == mask);
default:
panic("ffs_isblock: unknown fs_fragshift %d",
(int)fs->fs_fragshift);
}
}
/*
* check if a block is completely allocated
* returns true if all the corresponding bits in the free map are 0
* returns false if any corresponding bit in the free map is 1
*/
int
ffs_isfreeblock(fs, cp, h)
struct fs *fs;
u_char *cp;
int32_t h;
{
switch ((int)fs->fs_fragshift) {
case 3:
return (cp[h] == 0);
case 2:
return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
case 1:
return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
case 0:
return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
default:
panic("ffs_isfreeblock: unknown fs_fragshift %d",
(int)fs->fs_fragshift);
}
}
/*
* take a block out of the map
*/
void
ffs_clrblock(fs, cp, h)
struct fs *fs;
u_char *cp;
int32_t h;
{
switch ((int)fs->fs_fragshift) {
case 3:
cp[h] = 0;
return;
case 2:
cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
return;
case 1:
cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
return;
case 0:
cp[h >> 3] &= ~(0x01 << (h & 0x7));
return;
default:
panic("ffs_clrblock: unknown fs_fragshift %d",
(int)fs->fs_fragshift);
}
}
/*
* put a block into the map
*/
void
ffs_setblock(fs, cp, h)
struct fs *fs;
u_char *cp;
int32_t h;
{
switch ((int)fs->fs_fragshift) {
case 3:
cp[h] = 0xff;
return;
case 2:
cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
return;
case 1:
cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
return;
case 0:
cp[h >> 3] |= (0x01 << (h & 0x7));
return;
default:
panic("ffs_setblock: unknown fs_fragshift %d",
(int)fs->fs_fragshift);
}
}