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NetBSD/sys/ufs/ext2fs/ext2fs_alloc.c

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/* $NetBSD: ext2fs_alloc.c,v 1.9 2000/06/28 14:16:37 mrg Exp $ */
/*
* Copyright (c) 1997 Manuel Bouyer.
* 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. 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.
*
* @(#)ffs_alloc.c 8.11 (Berkeley) 10/27/94
* Modified for ext2fs by Manuel Bouyer.
*/
#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 <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ext2fs/ext2fs.h>
#include <ufs/ext2fs/ext2fs_extern.h>
u_long ext2gennumber;
static ufs_daddr_t ext2fs_alloccg __P((struct inode *, int, ufs_daddr_t, int));
static u_long ext2fs_dirpref __P((struct m_ext2fs *));
static void ext2fs_fserr __P((struct m_ext2fs *, u_int, char *));
static u_long ext2fs_hashalloc __P((struct inode *, int, long, int,
ufs_daddr_t (*)(struct inode *, int, ufs_daddr_t,
int)));
static ufs_daddr_t ext2fs_nodealloccg __P((struct inode *, int, ufs_daddr_t, int));
static ufs_daddr_t ext2fs_mapsearch __P((struct m_ext2fs *, char *, ufs_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 heirarchy 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(ip, lbn, bpref, cred, bnp)
struct inode *ip;
ufs_daddr_t lbn, bpref;
struct ucred *cred;
ufs_daddr_t *bnp;
{
struct m_ext2fs *fs;
ufs_daddr_t bno;
int cg;
*bnp = 0;
fs = ip->i_e2fs;
#ifdef DIAGNOSTIC
if (cred == NOCRED)
panic("ext2fs_alloc: missing credential\n");
#endif /* DIAGNOSTIC */
if (fs->e2fs.e2fs_fbcount == 0)
goto nospace;
if (cred->cr_uid != 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 = (ufs_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, cred->cr_uid, "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 heirarchy 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(v)
void *v;
{
struct vop_valloc_args /* {
struct vnode *a_pvp;
int a_mode;
struct ucred *a_cred;
struct vnode **a_vpp;
} */ *ap = v;
struct vnode *pvp = ap->a_pvp;
struct inode *pip;
struct m_ext2fs *fs;
struct inode *ip;
mode_t mode = ap->a_mode;
ino_t ino, ipref;
int cg, error;
*ap->a_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, ap->a_vpp);
if (error) {
VOP_VFREE(pvp, ino, mode);
return (error);
}
ip = VTOI(*ap->a_vpp);
if (ip->i_e2fs_mode && ip->i_e2fs_nlink != 0) {
printf("mode = 0%o, nlinks %d, inum = %d, fs = %s\n",
ip->i_e2fs_mode, ip->i_e2fs_nlink, ip->i_number, fs->e2fs_fsmnt);
panic("ext2fs_valloc: dup alloc");
}
memset(&ip->i_din, 0, sizeof(ip->i_din));
/*
* Set up a new generation number for this inode.
*/
if (++ext2gennumber < (u_long)time.tv_sec)
ext2gennumber = time.tv_sec;
ip->i_e2fs_gen = ext2gennumber;
return (0);
noinodes:
ext2fs_fserr(fs, ap->a_cred->cr_uid, "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(fs)
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 extention (see
* ufs/ufs/inode.h) help this.
*/
ufs_daddr_t
ext2fs_blkpref(ip, lbn, indx, bap)
struct inode *ip;
ufs_daddr_t lbn;
int indx;
ufs_daddr_t *bap;
{
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(ip, cg, pref, size, allocator)
struct inode *ip;
int cg;
long pref;
int size; /* size for data blocks, mode for inodes */
ufs_daddr_t (*allocator) __P((struct inode *, int, ufs_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 ufs_daddr_t
ext2fs_alloccg(ip, cg, bpref, size)
struct inode *ip;
int cg;
ufs_daddr_t bpref;
int size;
{
struct m_ext2fs *fs;
char *bbp;
struct buf *bp;
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, &bp);
if (error) {
brelse(bp);
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, (long)bno)) {
printf("ext2fs_alloccgblk: cg=%d bno=%d fs=%s\n",
cg, bno, fs->e2fs_fsmnt);
panic("ext2fs_alloccg: dup alloc");
}
#endif
setbit(bbp, (long)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 ufs_daddr_t
ext2fs_nodealloccg(ip, cg, ipref, mode)
struct inode *ip;
int cg;
ufs_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) */
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, &bp);
if (error) {
brelse(bp);
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 = %d, fs = %s\n",
cg, 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(ip, bno)
struct inode *ip;
ufs_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 %d, ino %d\n", bno, ip->i_number);
ext2fs_fserr(fs, ip->i_e2fs_uid, "bad block");
return;
}
error = bread(ip->i_devvp,
fsbtodb(fs, fs->e2fs_gd[cg].ext2bgd_b_bitmap),
(int)fs->e2fs_bsize, NOCRED, &bp);
if (error) {
brelse(bp);
return;
}
bbp = (char *)bp->b_data;
bno = dtogd(fs, bno);
if (isclr(bbp, bno)) {
printf("dev = 0x%x, block = %d, fs = %s\n",
ip->i_dev, 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(v)
void *v;
{
struct vop_vfree_args /* {
struct vnode *a_pvp;
ino_t a_ino;
int a_mode;
} */ *ap = v;
struct m_ext2fs *fs;
char *ibp;
struct inode *pip;
ino_t ino = ap->a_ino;
struct buf *bp;
int error, cg;
pip = VTOI(ap->a_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 = %d, fs = %s\n",
pip->i_dev, 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, &bp);
if (error) {
brelse(bp);
return (0);
}
ibp = (char *)bp->b_data;
ino = (ino - 1) % fs->e2fs.e2fs_ipg;
if (isclr(ibp, ino)) {
printf("dev = 0x%x, ino = %d, fs = %s\n",
pip->i_dev, 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 ((ap->a_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 ufs_daddr_t
ext2fs_mapsearch(fs, bbp, bpref)
struct m_ext2fs *fs;
char *bbp;
ufs_daddr_t bpref;
{
ufs_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(fs, uid, cp)
struct m_ext2fs *fs;
u_int uid;
char *cp;
{
log(LOG_ERR, "uid %d on %s: %s\n", uid, fs->e2fs_fsmnt, cp);
}
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