NetBSD-5.0.2/sys/ufs/ext2fs/ext2fs_alloc.c
/* $NetBSD: ext2fs_alloc.c,v 1.36.8.1 2008/11/29 23:10:18 snj 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_alloc.c 8.11 (Berkeley) 10/27/94
* Modified for ext2fs by Manuel Bouyer.
*/
/*
* Copyright (c) 1997 Manuel Bouyer.
*
* 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 Manuel Bouyer.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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_alloc.c 8.11 (Berkeley) 10/27/94
* Modified for ext2fs by Manuel Bouyer.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ext2fs_alloc.c,v 1.36.8.1 2008/11/29 23:10:18 snj Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/kauth.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ext2fs/ext2fs.h>
#include <ufs/ext2fs/ext2fs_extern.h>
u_long ext2gennumber;
static daddr_t ext2fs_alloccg(struct inode *, int, daddr_t, int);
static u_long ext2fs_dirpref(struct m_ext2fs *);
static void ext2fs_fserr(struct m_ext2fs *, u_int, const char *);
static u_long ext2fs_hashalloc(struct inode *, int, long, int,
daddr_t (*)(struct inode *, int, daddr_t,
int));
static daddr_t ext2fs_nodealloccg(struct inode *, int, daddr_t, int);
static daddr_t ext2fs_mapsearch(struct m_ext2fs *, char *, daddr_t);
/*
* Allocate a block in the file system.
*
* A preference may be optionally specified. If a preference is given
* the following hierarchy is used to allocate a block:
* 1) allocate the requested block.
* 2) allocate a rotationally optimal block in the same cylinder.
* 3) allocate a block in the same cylinder group.
* 4) quadradically rehash into other cylinder groups, until an
* available block is located.
* If no block preference is given the following hierarchy is used
* to allocate a block:
* 1) allocate a block in the cylinder group that contains the
* inode for the file.
* 2) quadradically rehash into other cylinder groups, until an
* available block is located.
*/
int
ext2fs_alloc(struct inode *ip, daddr_t lbn, daddr_t bpref,
kauth_cred_t cred, daddr_t *bnp)
{
struct m_ext2fs *fs;
daddr_t bno;
int cg;
*bnp = 0;
fs = ip->i_e2fs;
#ifdef DIAGNOSTIC
if (cred == NOCRED)
panic("ext2fs_alloc: missing credential");
#endif /* DIAGNOSTIC */
if (fs->e2fs.e2fs_fbcount == 0)
goto nospace;
if (kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, NULL) != 0 &&
freespace(fs) <= 0)
goto nospace;
if (bpref >= fs->e2fs.e2fs_bcount)
bpref = 0;
if (bpref == 0)
cg = ino_to_cg(fs, ip->i_number);
else
cg = dtog(fs, bpref);
bno = (daddr_t)ext2fs_hashalloc(ip, cg, bpref, fs->e2fs_bsize,
ext2fs_alloccg);
if (bno > 0) {
ip->i_e2fs_nblock += btodb(fs->e2fs_bsize);
ip->i_flag |= IN_CHANGE | IN_UPDATE;
*bnp = bno;
return (0);
}
nospace:
ext2fs_fserr(fs, kauth_cred_geteuid(cred), "file system full");
uprintf("\n%s: write failed, file system is full\n", fs->e2fs_fsmnt);
return (ENOSPC);
}
/*
* Allocate an inode in the file system.
*
* If allocating a directory, use ext2fs_dirpref to select the inode.
* If allocating in a directory, the following hierarchy is followed:
* 1) allocate the preferred inode.
* 2) allocate an inode in the same cylinder group.
* 3) quadradically rehash into other cylinder groups, until an
* available inode is located.
* If no inode preference is given the following hierarchy is used
* to allocate an inode:
* 1) allocate an inode in cylinder group 0.
* 2) quadradically rehash into other cylinder groups, until an
* available inode is located.
*/
int
ext2fs_valloc(struct vnode *pvp, int mode, kauth_cred_t cred,
struct vnode **vpp)
{
struct inode *pip;
struct m_ext2fs *fs;
struct inode *ip;
ino_t ino, ipref;
int cg, error;
*vpp = NULL;
pip = VTOI(pvp);
fs = pip->i_e2fs;
if (fs->e2fs.e2fs_ficount == 0)
goto noinodes;
if ((mode & IFMT) == IFDIR)
cg = ext2fs_dirpref(fs);
else
cg = ino_to_cg(fs, pip->i_number);
ipref = cg * fs->e2fs.e2fs_ipg + 1;
ino = (ino_t)ext2fs_hashalloc(pip, cg, (long)ipref, mode, ext2fs_nodealloccg);
if (ino == 0)
goto noinodes;
error = VFS_VGET(pvp->v_mount, ino, vpp);
if (error) {
ext2fs_vfree(pvp, ino, mode);
return (error);
}
ip = VTOI(*vpp);
if (ip->i_e2fs_mode && ip->i_e2fs_nlink != 0) {
printf("mode = 0%o, nlinks %d, inum = %llu, fs = %s\n",
ip->i_e2fs_mode, ip->i_e2fs_nlink,
(unsigned long long)ip->i_number, fs->e2fs_fsmnt);
panic("ext2fs_valloc: dup alloc");
}
memset(ip->i_din.e2fs_din, 0, sizeof(struct ext2fs_dinode));
/*
* Set up a new generation number for this inode.
*/
if (++ext2gennumber < time_second)
ext2gennumber = time_second;
ip->i_e2fs_gen = ext2gennumber;
return (0);
noinodes:
ext2fs_fserr(fs, kauth_cred_geteuid(cred), "out of inodes");
uprintf("\n%s: create/symlink failed, no inodes free\n", fs->e2fs_fsmnt);
return (ENOSPC);
}
/*
* Find a cylinder to place a directory.
*
* The policy implemented by this algorithm is to select from
* among those cylinder groups with above the average number of
* free inodes, the one with the smallest number of directories.
*/
static u_long
ext2fs_dirpref(struct m_ext2fs *fs)
{
int cg, maxspace, mincg, avgifree;
avgifree = fs->e2fs.e2fs_ficount / fs->e2fs_ncg;
maxspace = 0;
mincg = -1;
for (cg = 0; cg < fs->e2fs_ncg; cg++)
if ( fs->e2fs_gd[cg].ext2bgd_nifree >= avgifree) {
if (mincg == -1 || fs->e2fs_gd[cg].ext2bgd_nbfree > maxspace) {
mincg = cg;
maxspace = fs->e2fs_gd[cg].ext2bgd_nbfree;
}
}
return mincg;
}
/*
* Select the desired position for the next block in a file. The file is
* logically divided into sections. The first section is composed of the
* direct blocks. Each additional section contains fs_maxbpg blocks.
*
* If no blocks have been allocated in the first section, the policy is to
* request a block in the same cylinder group as the inode that describes
* the file. Otherwise, the policy is to try to allocate the blocks
* contigously. The two fields of the ext2 inode extension (see
* ufs/ufs/inode.h) help this.
*/
daddr_t
ext2fs_blkpref(struct inode *ip, daddr_t lbn, int indx,
int32_t *bap /* XXX ondisk32 */)
{
struct m_ext2fs *fs;
int cg, i;
fs = ip->i_e2fs;
/*
* if we are doing contigous lbn allocation, try to alloc blocks
* contigously on disk
*/
if ( ip->i_e2fs_last_blk && lbn == ip->i_e2fs_last_lblk + 1) {
return ip->i_e2fs_last_blk + 1;
}
/*
* bap, if provided, gives us a list of blocks to which we want to
* stay close
*/
if (bap) {
for (i = indx; i >= 0 ; i--) {
if (bap[i]) {
return fs2h32(bap[i]) + 1;
}
}
}
/* fall back to the first block of the cylinder containing the inode */
cg = ino_to_cg(fs, ip->i_number);
return fs->e2fs.e2fs_bpg * cg + fs->e2fs.e2fs_first_dblock + 1;
}
/*
* Implement the cylinder overflow algorithm.
*
* The policy implemented by this algorithm is:
* 1) allocate the block in its requested cylinder group.
* 2) quadradically rehash on the cylinder group number.
* 3) brute force search for a free block.
*/
static u_long
ext2fs_hashalloc(struct inode *ip, int cg, long pref, int size,
daddr_t (*allocator)(struct inode *, int, daddr_t, int))
{
struct m_ext2fs *fs;
long result;
int i, icg = cg;
fs = ip->i_e2fs;
/*
* 1: preferred cylinder group
*/
result = (*allocator)(ip, cg, pref, size);
if (result)
return (result);
/*
* 2: quadratic rehash
*/
for (i = 1; i < fs->e2fs_ncg; i *= 2) {
cg += i;
if (cg >= fs->e2fs_ncg)
cg -= fs->e2fs_ncg;
result = (*allocator)(ip, cg, 0, size);
if (result)
return (result);
}
/*
* 3: brute force search
* Note that we start at i == 2, since 0 was checked initially,
* and 1 is always checked in the quadratic rehash.
*/
cg = (icg + 2) % fs->e2fs_ncg;
for (i = 2; i < fs->e2fs_ncg; i++) {
result = (*allocator)(ip, cg, 0, size);
if (result)
return (result);
cg++;
if (cg == fs->e2fs_ncg)
cg = 0;
}
return (0);
}
/*
* Determine whether a block can be allocated.
*
* Check to see if a block of the appropriate size is available,
* and if it is, allocate it.
*/
static daddr_t
ext2fs_alloccg(struct inode *ip, int cg, daddr_t bpref, int size)
{
struct m_ext2fs *fs;
char *bbp;
struct buf *bp;
/* XXX ondisk32 */
int error, bno, start, end, loc;
fs = ip->i_e2fs;
if (fs->e2fs_gd[cg].ext2bgd_nbfree == 0)
return (0);
error = bread(ip->i_devvp, fsbtodb(fs,
fs->e2fs_gd[cg].ext2bgd_b_bitmap),
(int)fs->e2fs_bsize, NOCRED, B_MODIFY, &bp);
if (error) {
brelse(bp, 0);
return (0);
}
bbp = (char *)bp->b_data;
if (dtog(fs, bpref) != cg)
bpref = 0;
if (bpref != 0) {
bpref = dtogd(fs, bpref);
/*
* if the requested block is available, use it
*/
if (isclr(bbp, bpref)) {
bno = bpref;
goto gotit;
}
}
/*
* no blocks in the requested cylinder, so take next
* available one in this cylinder group.
* first try to get 8 contigous blocks, then fall back to a single
* block.
*/
if (bpref)
start = dtogd(fs, bpref) / NBBY;
else
start = 0;
end = howmany(fs->e2fs.e2fs_fpg, NBBY) - start;
for (loc = start; loc < end; loc++) {
if (bbp[loc] == 0) {
bno = loc * NBBY;
goto gotit;
}
}
for (loc = 0; loc < start; loc++) {
if (bbp[loc] == 0) {
bno = loc * NBBY;
goto gotit;
}
}
bno = ext2fs_mapsearch(fs, bbp, bpref);
if (bno < 0)
return (0);
gotit:
#ifdef DIAGNOSTIC
if (isset(bbp, (daddr_t)bno)) {
printf("ext2fs_alloccgblk: cg=%d bno=%d fs=%s\n",
cg, bno, fs->e2fs_fsmnt);
panic("ext2fs_alloccg: dup alloc");
}
#endif
setbit(bbp, (daddr_t)bno);
fs->e2fs.e2fs_fbcount--;
fs->e2fs_gd[cg].ext2bgd_nbfree--;
fs->e2fs_fmod = 1;
bdwrite(bp);
return (cg * fs->e2fs.e2fs_fpg + fs->e2fs.e2fs_first_dblock + bno);
}
/*
* Determine whether an inode can be allocated.
*
* Check to see if an inode is available, and if it is,
* allocate it using the following policy:
* 1) allocate the requested inode.
* 2) allocate the next available inode after the requested
* inode in the specified cylinder group.
*/
static daddr_t
ext2fs_nodealloccg(struct inode *ip, int cg, daddr_t ipref, int mode)
{
struct m_ext2fs *fs;
char *ibp;
struct buf *bp;
int error, start, len, loc, map, i;
ipref--; /* to avoid a lot of (ipref -1) */
if (ipref == -1)
ipref = 0;
fs = ip->i_e2fs;
if (fs->e2fs_gd[cg].ext2bgd_nifree == 0)
return (0);
error = bread(ip->i_devvp, fsbtodb(fs,
fs->e2fs_gd[cg].ext2bgd_i_bitmap),
(int)fs->e2fs_bsize, NOCRED, B_MODIFY, &bp);
if (error) {
brelse(bp, 0);
return (0);
}
ibp = (char *)bp->b_data;
if (ipref) {
ipref %= fs->e2fs.e2fs_ipg;
if (isclr(ibp, ipref))
goto gotit;
}
start = ipref / NBBY;
len = howmany(fs->e2fs.e2fs_ipg - ipref, NBBY);
loc = skpc(0xff, len, &ibp[start]);
if (loc == 0) {
len = start + 1;
start = 0;
loc = skpc(0xff, len, &ibp[0]);
if (loc == 0) {
printf("cg = %d, ipref = %lld, fs = %s\n",
cg, (long long)ipref, fs->e2fs_fsmnt);
panic("ext2fs_nodealloccg: map corrupted");
/* NOTREACHED */
}
}
i = start + len - loc;
map = ibp[i];
ipref = i * NBBY;
for (i = 1; i < (1 << NBBY); i <<= 1, ipref++) {
if ((map & i) == 0) {
goto gotit;
}
}
printf("fs = %s\n", fs->e2fs_fsmnt);
panic("ext2fs_nodealloccg: block not in map");
/* NOTREACHED */
gotit:
setbit(ibp, ipref);
fs->e2fs.e2fs_ficount--;
fs->e2fs_gd[cg].ext2bgd_nifree--;
fs->e2fs_fmod = 1;
if ((mode & IFMT) == IFDIR) {
fs->e2fs_gd[cg].ext2bgd_ndirs++;
}
bdwrite(bp);
return (cg * fs->e2fs.e2fs_ipg + ipref +1);
}
/*
* Free a block.
*
* The specified block is placed back in the
* free map.
*/
void
ext2fs_blkfree(struct inode *ip, daddr_t bno)
{
struct m_ext2fs *fs;
char *bbp;
struct buf *bp;
int error, cg;
fs = ip->i_e2fs;
cg = dtog(fs, bno);
if ((u_int)bno >= fs->e2fs.e2fs_bcount) {
printf("bad block %lld, ino %llu\n", (long long)bno,
(unsigned long long)ip->i_number);
ext2fs_fserr(fs, ip->i_uid, "bad block");
return;
}
error = bread(ip->i_devvp,
fsbtodb(fs, fs->e2fs_gd[cg].ext2bgd_b_bitmap),
(int)fs->e2fs_bsize, NOCRED, B_MODIFY, &bp);
if (error) {
brelse(bp, 0);
return;
}
bbp = (char *)bp->b_data;
bno = dtogd(fs, bno);
if (isclr(bbp, bno)) {
printf("dev = 0x%x, block = %lld, fs = %s\n",
ip->i_dev, (long long)bno, fs->e2fs_fsmnt);
panic("blkfree: freeing free block");
}
clrbit(bbp, bno);
fs->e2fs.e2fs_fbcount++;
fs->e2fs_gd[cg].ext2bgd_nbfree++;
fs->e2fs_fmod = 1;
bdwrite(bp);
}
/*
* Free an inode.
*
* The specified inode is placed back in the free map.
*/
int
ext2fs_vfree(struct vnode *pvp, ino_t ino, int mode)
{
struct m_ext2fs *fs;
char *ibp;
struct inode *pip;
struct buf *bp;
int error, cg;
pip = VTOI(pvp);
fs = pip->i_e2fs;
if ((u_int)ino > fs->e2fs.e2fs_icount || (u_int)ino < EXT2_FIRSTINO)
panic("ifree: range: dev = 0x%x, ino = %llu, fs = %s",
pip->i_dev, (unsigned long long)ino, fs->e2fs_fsmnt);
cg = ino_to_cg(fs, ino);
error = bread(pip->i_devvp,
fsbtodb(fs, fs->e2fs_gd[cg].ext2bgd_i_bitmap),
(int)fs->e2fs_bsize, NOCRED, B_MODIFY, &bp);
if (error) {
brelse(bp, 0);
return (0);
}
ibp = (char *)bp->b_data;
ino = (ino - 1) % fs->e2fs.e2fs_ipg;
if (isclr(ibp, ino)) {
printf("dev = 0x%x, ino = %llu, fs = %s\n",
pip->i_dev, (unsigned long long)ino, fs->e2fs_fsmnt);
if (fs->e2fs_ronly == 0)
panic("ifree: freeing free inode");
}
clrbit(ibp, ino);
fs->e2fs.e2fs_ficount++;
fs->e2fs_gd[cg].ext2bgd_nifree++;
if ((mode & IFMT) == IFDIR) {
fs->e2fs_gd[cg].ext2bgd_ndirs--;
}
fs->e2fs_fmod = 1;
bdwrite(bp);
return (0);
}
/*
* Find a block in the specified cylinder group.
*
* It is a panic if a request is made to find a block if none are
* available.
*/
static daddr_t
ext2fs_mapsearch(struct m_ext2fs *fs, char *bbp, daddr_t bpref)
{
daddr_t bno;
int start, len, loc, i, map;
/*
* find the fragment by searching through the free block
* map for an appropriate bit pattern
*/
if (bpref)
start = dtogd(fs, bpref) / NBBY;
else
start = 0;
len = howmany(fs->e2fs.e2fs_fpg, NBBY) - start;
loc = skpc(0xff, len, &bbp[start]);
if (loc == 0) {
len = start + 1;
start = 0;
loc = skpc(0xff, len, &bbp[start]);
if (loc == 0) {
printf("start = %d, len = %d, fs = %s\n",
start, len, fs->e2fs_fsmnt);
panic("ext2fs_alloccg: map corrupted");
/* NOTREACHED */
}
}
i = start + len - loc;
map = bbp[i];
bno = i * NBBY;
for (i = 1; i < (1 << NBBY); i <<= 1, bno++) {
if ((map & i) == 0)
return (bno);
}
printf("fs = %s\n", fs->e2fs_fsmnt);
panic("ext2fs_mapsearch: block not in map");
/* NOTREACHED */
}
/*
* Fserr prints the name of a file system with an error diagnostic.
*
* The form of the error message is:
* fs: error message
*/
static void
ext2fs_fserr(struct m_ext2fs *fs, u_int uid, const char *cp)
{
log(LOG_ERR, "uid %d on %s: %s\n", uid, fs->e2fs_fsmnt, cp);
}