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BSD 4_3 release
[unix-history] / usr / src / sys / sys / ufs_alloc.c
/*
* Copyright (c) 1982, 1986 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
* @(#)ufs_alloc.c 7.1 (Berkeley) 6/5/86
*/
#include "param.h"
#include "systm.h"
#include "mount.h"
#include "fs.h"
#include "buf.h"
#include "inode.h"
#include "dir.h"
#include "user.h"
#include "quota.h"
#include "kernel.h"
#include "syslog.h"
#include "cmap.h"
extern u_long hashalloc();
extern ino_t ialloccg();
extern daddr_t alloccg();
extern daddr_t alloccgblk();
extern daddr_t fragextend();
extern daddr_t blkpref();
extern daddr_t mapsearch();
extern int inside[], around[];
extern unsigned char *fragtbl[];
/*
* Allocate a block in the file system.
*
* The size of the requested block is given, which must be some
* multiple of fs_fsize and <= fs_bsize.
* 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.
*/
struct buf *
alloc(ip, bpref, size)
register struct inode *ip;
daddr_t bpref;
int size;
{
daddr_t bno;
register struct fs *fs;
register struct buf *bp;
int cg;
fs = ip->i_fs;
if ((unsigned)size > fs->fs_bsize || fragoff(fs, size) != 0) {
printf("dev = 0x%x, bsize = %d, size = %d, fs = %s\n",
ip->i_dev, fs->fs_bsize, size, fs->fs_fsmnt);
panic("alloc: bad size");
}
if (size == fs->fs_bsize && fs->fs_cstotal.cs_nbfree == 0)
goto nospace;
if (u.u_uid != 0 && freespace(fs, fs->fs_minfree) <= 0)
goto nospace;
#ifdef QUOTA
u.u_error = chkdq(ip, (long)btodb(size), 0);
if (u.u_error)
return (NULL);
#endif
if (bpref >= fs->fs_size)
bpref = 0;
if (bpref == 0)
cg = itog(fs, ip->i_number);
else
cg = dtog(fs, bpref);
bno = (daddr_t)hashalloc(ip, cg, (long)bpref, size,
(u_long (*)())alloccg);
if (bno <= 0)
goto nospace;
ip->i_blocks += btodb(size);
ip->i_flag |= IUPD|ICHG;
bp = getblk(ip->i_dev, fsbtodb(fs, bno), size);
clrbuf(bp);
return (bp);
nospace:
fserr(fs, "file system full");
uprintf("\n%s: write failed, file system is full\n", fs->fs_fsmnt);
u.u_error = ENOSPC;
return (NULL);
}
/*
* Reallocate a fragment to a bigger size
*
* The number and size of the old block is given, and a preference
* and new size is also specified. The allocator attempts to extend
* the original block. Failing that, the regular block allocator is
* invoked to get an appropriate block.
*/
struct buf *
realloccg(ip, bprev, bpref, osize, nsize)
register struct inode *ip;
daddr_t bprev, bpref;
int osize, nsize;
{
register struct fs *fs;
register struct buf *bp, *obp;
int cg, request;
daddr_t bno, bn;
int i, count, s;
extern struct cmap *mfind();
fs = ip->i_fs;
if ((unsigned)osize > fs->fs_bsize || fragoff(fs, osize) != 0 ||
(unsigned)nsize > fs->fs_bsize || fragoff(fs, nsize) != 0) {
printf("dev = 0x%x, bsize = %d, osize = %d, nsize = %d, fs = %s\n",
ip->i_dev, fs->fs_bsize, osize, nsize, fs->fs_fsmnt);
panic("realloccg: bad size");
}
if (u.u_uid != 0 && freespace(fs, fs->fs_minfree) <= 0)
goto nospace;
if (bprev == 0) {
printf("dev = 0x%x, bsize = %d, bprev = %d, fs = %s\n",
ip->i_dev, fs->fs_bsize, bprev, fs->fs_fsmnt);
panic("realloccg: bad bprev");
}
#ifdef QUOTA
u.u_error = chkdq(ip, (long)btodb(nsize - osize), 0);
if (u.u_error)
return (NULL);
#endif
cg = dtog(fs, bprev);
bno = fragextend(ip, cg, (long)bprev, osize, nsize);
if (bno != 0) {
do {
bp = bread(ip->i_dev, fsbtodb(fs, bno), osize);
if (bp->b_flags & B_ERROR) {
brelse(bp);
return (NULL);
}
} while (brealloc(bp, nsize) == 0);
bp->b_flags |= B_DONE;
bzero(bp->b_un.b_addr + osize, (unsigned)nsize - osize);
ip->i_blocks += btodb(nsize - osize);
ip->i_flag |= IUPD|ICHG;
return (bp);
}
if (bpref >= fs->fs_size)
bpref = 0;
switch ((int)fs->fs_optim) {
case FS_OPTSPACE:
/*
* Allocate an exact sized fragment. Although this makes
* best use of space, we will waste time relocating it if
* the file continues to grow. If the fragmentation is
* less than half of the minimum free reserve, we choose
* to begin optimizing for time.
*/
request = nsize;
if (fs->fs_minfree < 5 ||
fs->fs_cstotal.cs_nffree >
fs->fs_dsize * fs->fs_minfree / (2 * 100))
break;
log(LOG_NOTICE, "%s: optimization changed from SPACE to TIME\n",
fs->fs_fsmnt);
fs->fs_optim = FS_OPTTIME;
break;
case FS_OPTTIME:
/*
* At this point we have discovered a file that is trying
* to grow a small fragment to a larger fragment. To save
* time, we allocate a full sized block, then free the
* unused portion. If the file continues to grow, the
* `fragextend' call above will be able to grow it in place
* without further copying. If aberrant programs cause
* disk fragmentation to grow within 2% of the free reserve,
* we choose to begin optimizing for space.
*/
request = fs->fs_bsize;
if (fs->fs_cstotal.cs_nffree <
fs->fs_dsize * (fs->fs_minfree - 2) / 100)
break;
log(LOG_NOTICE, "%s: optimization changed from TIME to SPACE\n",
fs->fs_fsmnt);
fs->fs_optim = FS_OPTSPACE;
break;
default:
printf("dev = 0x%x, optim = %d, fs = %s\n",
ip->i_dev, fs->fs_optim, fs->fs_fsmnt);
panic("realloccg: bad optim");
/* NOTREACHED */
}
bno = (daddr_t)hashalloc(ip, cg, (long)bpref, request,
(u_long (*)())alloccg);
if (bno > 0) {
obp = bread(ip->i_dev, fsbtodb(fs, bprev), osize);
if (obp->b_flags & B_ERROR) {
brelse(obp);
return (NULL);
}
bn = fsbtodb(fs, bno);
bp = getblk(ip->i_dev, bn, nsize);
bcopy(obp->b_un.b_addr, bp->b_un.b_addr, (u_int)osize);
count = howmany(osize, DEV_BSIZE);
s = splimp();
for (i = 0; i < count; i += CLBYTES / DEV_BSIZE)
if (mfind(ip->i_dev, bn + i))
munhash(ip->i_dev, bn + i);
splx(s);
bzero(bp->b_un.b_addr + osize, (unsigned)nsize - osize);
if (obp->b_flags & B_DELWRI) {
obp->b_flags &= ~B_DELWRI;
u.u_ru.ru_oublock--; /* delete charge */
}
brelse(obp);
free(ip, bprev, (off_t)osize);
if (nsize < request)
free(ip, bno + numfrags(fs, nsize),
(off_t)(request - nsize));
ip->i_blocks += btodb(nsize - osize);
ip->i_flag |= IUPD|ICHG;
return (bp);
}
nospace:
/*
* no space available
*/
fserr(fs, "file system full");
uprintf("\n%s: write failed, file system is full\n", fs->fs_fsmnt);
u.u_error = ENOSPC;
return (NULL);
}
/*
* Allocate an inode in the file system.
*
* A preference may be optionally specified. If a preference is given
* the following hierarchy is used to allocate an inode:
* 1) allocate the requested 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.
*/
struct inode *
ialloc(pip, ipref, mode)
register struct inode *pip;
ino_t ipref;
int mode;
{
ino_t ino;
register struct fs *fs;
register struct inode *ip;
int cg;
fs = pip->i_fs;
if (fs->fs_cstotal.cs_nifree == 0)
goto noinodes;
#ifdef QUOTA
u.u_error = chkiq(pip->i_dev, (struct inode *)NULL, u.u_uid, 0);
if (u.u_error)
return (NULL);
#endif
if (ipref >= fs->fs_ncg * fs->fs_ipg)
ipref = 0;
cg = itog(fs, ipref);
ino = (ino_t)hashalloc(pip, cg, (long)ipref, mode, ialloccg);
if (ino == 0)
goto noinodes;
ip = iget(pip->i_dev, pip->i_fs, ino);
if (ip == NULL) {
ifree(pip, ino, 0);
return (NULL);
}
if (ip->i_mode) {
printf("mode = 0%o, inum = %d, fs = %s\n",
ip->i_mode, ip->i_number, fs->fs_fsmnt);
panic("ialloc: dup alloc");
}
if (ip->i_blocks) { /* XXX */
printf("free inode %s/%d had %d blocks\n",
fs->fs_fsmnt, ino, ip->i_blocks);
ip->i_blocks = 0;
}
return (ip);
noinodes:
fserr(fs, "out of inodes");
uprintf("\n%s: create/symlink failed, no inodes free\n", fs->fs_fsmnt);
u.u_error = ENOSPC;
return (NULL);
}
/*
* 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.
*/
ino_t
dirpref(fs)
register struct fs *fs;
{
int cg, minndir, mincg, avgifree;
avgifree = fs->fs_cstotal.cs_nifree / fs->fs_ncg;
minndir = fs->fs_ipg;
mincg = 0;
for (cg = 0; cg < fs->fs_ncg; cg++)
if (fs->fs_cs(fs, cg).cs_ndir < minndir &&
fs->fs_cs(fs, cg).cs_nifree >= avgifree) {
mincg = cg;
minndir = fs->fs_cs(fs, cg).cs_ndir;
}
return ((ino_t)(fs->fs_ipg * 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. If no blocks have been allocated in any other section, the
* policy is to place the section in a cylinder group with a greater than
* average number of free blocks. An appropriate cylinder group is found
* by using a rotor that sweeps the cylinder groups. When a new group of
* blocks is needed, the sweep begins in the cylinder group following the
* cylinder group from which the previous allocation was made. The sweep
* continues until a cylinder group with greater than the average number
* of free blocks is found. If the allocation is for the first block in an
* indirect block, the information on the previous allocation is unavailable;
* here a best guess is made based upon the logical block number being
* allocated.
*
* If a section is already partially allocated, the policy is to
* contiguously allocate fs_maxcontig blocks. The end of one of these
* contiguous blocks and the beginning of the next is physically separated
* so that the disk head will be in transit between them for at least
* fs_rotdelay milliseconds. This is to allow time for the processor to
* schedule another I/O transfer.
*/
daddr_t
blkpref(ip, lbn, indx, bap)
struct inode *ip;
daddr_t lbn;
int indx;
daddr_t *bap;
{
register struct fs *fs;
register int cg;
int avgbfree, startcg;
daddr_t nextblk;
fs = ip->i_fs;
if (indx % fs->fs_maxbpg == 0 || bap[indx - 1] == 0) {
if (lbn < NDADDR) {
cg = itog(fs, ip->i_number);
return (fs->fs_fpg * cg + fs->fs_frag);
}
/*
* Find a cylinder with greater than average number of
* unused data blocks.
*/
if (indx == 0 || bap[indx - 1] == 0)
startcg = itog(fs, ip->i_number) + lbn / fs->fs_maxbpg;
else
startcg = dtog(fs, bap[indx - 1]) + 1;
startcg %= fs->fs_ncg;
avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
for (cg = startcg; cg < fs->fs_ncg; cg++)
if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
fs->fs_cgrotor = cg;
return (fs->fs_fpg * cg + fs->fs_frag);
}
for (cg = 0; cg <= startcg; cg++)
if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
fs->fs_cgrotor = cg;
return (fs->fs_fpg * cg + fs->fs_frag);
}
return (NULL);
}
/*
* One or more previous blocks have been laid out. If less
* than fs_maxcontig previous blocks are contiguous, the
* next block is requested contiguously, otherwise it is
* requested rotationally delayed by fs_rotdelay milliseconds.
*/
nextblk = bap[indx - 1] + fs->fs_frag;
if (indx > fs->fs_maxcontig &&
bap[indx - fs->fs_maxcontig] + blkstofrags(fs, fs->fs_maxcontig)
!= nextblk)
return (nextblk);
if (fs->fs_rotdelay != 0)
/*
* Here we convert ms of delay to frags as:
* (frags) = (ms) * (rev/sec) * (sect/rev) /
* ((sect/frag) * (ms/sec))
* then round up to the next block.
*/
nextblk += roundup(fs->fs_rotdelay * fs->fs_rps * fs->fs_nsect /
(NSPF(fs) * 1000), fs->fs_frag);
return (nextblk);
}
/*
* 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.
*/
/*VARARGS5*/
u_long
hashalloc(ip, cg, pref, size, allocator)
struct inode *ip;
int cg;
long pref;
int size; /* size for data blocks, mode for inodes */
u_long (*allocator)();
{
register struct fs *fs;
long result;
int i, icg = cg;
fs = ip->i_fs;
/*
* 1: preferred cylinder group
*/
result = (*allocator)(ip, cg, pref, size);
if (result)
return (result);
/*
* 2: quadratic rehash
*/
for (i = 1; i < fs->fs_ncg; i *= 2) {
cg += i;
if (cg >= fs->fs_ncg)
cg -= fs->fs_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->fs_ncg;
for (i = 2; i < fs->fs_ncg; i++) {
result = (*allocator)(ip, cg, 0, size);
if (result)
return (result);
cg++;
if (cg == fs->fs_ncg)
cg = 0;
}
return (NULL);
}
/*
* Determine whether a fragment can be extended.
*
* Check to see if the necessary fragments are available, and
* if they are, allocate them.
*/
daddr_t
fragextend(ip, cg, bprev, osize, nsize)
struct inode *ip;
int cg;
long bprev;
int osize, nsize;
{
register struct fs *fs;
register struct buf *bp;
register struct cg *cgp;
long bno;
int frags, bbase;
int i;
fs = ip->i_fs;
if (fs->fs_cs(fs, cg).cs_nffree < numfrags(fs, nsize - osize))
return (NULL);
frags = numfrags(fs, nsize);
bbase = fragnum(fs, bprev);
if (bbase > fragnum(fs, (bprev + frags - 1))) {
/* cannot extend across a block boundry */
return (NULL);
}
bp = bread(ip->i_dev, fsbtodb(fs, cgtod(fs, cg)), (int)fs->fs_cgsize);
cgp = bp->b_un.b_cg;
if (bp->b_flags & B_ERROR || cgp->cg_magic != CG_MAGIC) {
brelse(bp);
return (NULL);
}
cgp->cg_time = time.tv_sec;
bno = dtogd(fs, bprev);
for (i = numfrags(fs, osize); i < frags; i++)
if (isclr(cgp->cg_free, bno + i)) {
brelse(bp);
return (NULL);
}
/*
* the current fragment can be extended
* deduct the count on fragment being extended into
* increase the count on the remaining fragment (if any)
* allocate the extended piece
*/
for (i = frags; i < fs->fs_frag - bbase; i++)
if (isclr(cgp->cg_free, bno + i))
break;
cgp->cg_frsum[i - numfrags(fs, osize)]--;
if (i != frags)
cgp->cg_frsum[i - frags]++;
for (i = numfrags(fs, osize); i < frags; i++) {
clrbit(cgp->cg_free, bno + i);
cgp->cg_cs.cs_nffree--;
fs->fs_cstotal.cs_nffree--;
fs->fs_cs(fs, cg).cs_nffree--;
}
fs->fs_fmod++;
bdwrite(bp);
return (bprev);
}
/*
* Determine whether a block can be allocated.
*
* Check to see if a block of the apprpriate size is available,
* and if it is, allocate it.
*/
daddr_t
alloccg(ip, cg, bpref, size)
struct inode *ip;
int cg;
daddr_t bpref;
int size;
{
register struct fs *fs;
register struct buf *bp;
register struct cg *cgp;
int bno, frags;
int allocsiz;
register int i;
fs = ip->i_fs;
if (fs->fs_cs(fs, cg).cs_nbfree == 0 && size == fs->fs_bsize)
return (NULL);
bp = bread(ip->i_dev, fsbtodb(fs, cgtod(fs, cg)), (int)fs->fs_cgsize);
cgp = bp->b_un.b_cg;
if (bp->b_flags & B_ERROR || cgp->cg_magic != CG_MAGIC ||
(cgp->cg_cs.cs_nbfree == 0 && size == fs->fs_bsize)) {
brelse(bp);
return (NULL);
}
cgp->cg_time = time.tv_sec;
if (size == fs->fs_bsize) {
bno = alloccgblk(fs, cgp, bpref);
bdwrite(bp);
return (bno);
}
/*
* check to see if any fragments are already available
* allocsiz is the size which will be allocated, hacking
* it down to a smaller size if necessary
*/
frags = numfrags(fs, size);
for (allocsiz = frags; allocsiz < fs->fs_frag; allocsiz++)
if (cgp->cg_frsum[allocsiz] != 0)
break;
if (allocsiz == fs->fs_frag) {
/*
* no fragments were available, so a block will be
* allocated, and hacked up
*/
if (cgp->cg_cs.cs_nbfree == 0) {
brelse(bp);
return (NULL);
}
bno = alloccgblk(fs, cgp, bpref);
bpref = dtogd(fs, bno);
for (i = frags; i < fs->fs_frag; i++)
setbit(cgp->cg_free, bpref + i);
i = fs->fs_frag - frags;
cgp->cg_cs.cs_nffree += i;
fs->fs_cstotal.cs_nffree += i;
fs->fs_cs(fs, cg).cs_nffree += i;
fs->fs_fmod++;
cgp->cg_frsum[i]++;
bdwrite(bp);
return (bno);
}
bno = mapsearch(fs, cgp, bpref, allocsiz);
if (bno < 0) {
brelse(bp);
return (NULL);
}
for (i = 0; i < frags; i++)
clrbit(cgp->cg_free, bno + i);
cgp->cg_cs.cs_nffree -= frags;
fs->fs_cstotal.cs_nffree -= frags;
fs->fs_cs(fs, cg).cs_nffree -= frags;
fs->fs_fmod++;
cgp->cg_frsum[allocsiz]--;
if (frags != allocsiz)
cgp->cg_frsum[allocsiz - frags]++;
bdwrite(bp);
return (cg * fs->fs_fpg + bno);
}
/*
* Allocate a block in a cylinder group.
*
* This algorithm implements the following policy:
* 1) allocate the requested block.
* 2) allocate a rotationally optimal block in the same cylinder.
* 3) allocate the next available block on the block rotor for the
* specified cylinder group.
* Note that this routine only allocates fs_bsize blocks; these
* blocks may be fragmented by the routine that allocates them.
*/
daddr_t
alloccgblk(fs, cgp, bpref)
register struct fs *fs;
register struct cg *cgp;
daddr_t bpref;
{
daddr_t bno;
int cylno, pos, delta;
short *cylbp;
register int i;
if (bpref == 0) {
bpref = cgp->cg_rotor;
goto norot;
}
bpref = blknum(fs, bpref);
bpref = dtogd(fs, bpref);
/*
* if the requested block is available, use it
*/
if (isblock(fs, cgp->cg_free, fragstoblks(fs, bpref))) {
bno = bpref;
goto gotit;
}
/*
* check for a block available on the same cylinder
*/
cylno = cbtocylno(fs, bpref);
if (cgp->cg_btot[cylno] == 0)
goto norot;
if (fs->fs_cpc == 0) {
/*
* block layout info is not available, so just have
* to take any block in this cylinder.
*/
bpref = howmany(fs->fs_spc * cylno, NSPF(fs));
goto norot;
}
/*
* check the summary information to see if a block is
* available in the requested cylinder starting at the
* requested rotational position and proceeding around.
*/
cylbp = cgp->cg_b[cylno];
pos = cbtorpos(fs, bpref);
for (i = pos; i < NRPOS; i++)
if (cylbp[i] > 0)
break;
if (i == NRPOS)
for (i = 0; i < pos; i++)
if (cylbp[i] > 0)
break;
if (cylbp[i] > 0) {
/*
* found a rotational position, now find the actual
* block. A panic if none is actually there.
*/
pos = cylno % fs->fs_cpc;
bno = (cylno - pos) * fs->fs_spc / NSPB(fs);
if (fs->fs_postbl[pos][i] == -1) {
printf("pos = %d, i = %d, fs = %s\n",
pos, i, fs->fs_fsmnt);
panic("alloccgblk: cyl groups corrupted");
}
for (i = fs->fs_postbl[pos][i];; ) {
if (isblock(fs, cgp->cg_free, bno + i)) {
bno = blkstofrags(fs, (bno + i));
goto gotit;
}
delta = fs->fs_rotbl[i];
if (delta <= 0 || delta > MAXBPC - i)
break;
i += delta;
}
printf("pos = %d, i = %d, fs = %s\n", pos, i, fs->fs_fsmnt);
panic("alloccgblk: can't find blk in cyl");
}
norot:
/*
* no blocks in the requested cylinder, so take next
* available one in this cylinder group.
*/
bno = mapsearch(fs, cgp, bpref, (int)fs->fs_frag);
if (bno < 0)
return (NULL);
cgp->cg_rotor = bno;
gotit:
clrblock(fs, cgp->cg_free, (long)fragstoblks(fs, bno));
cgp->cg_cs.cs_nbfree--;
fs->fs_cstotal.cs_nbfree--;
fs->fs_cs(fs, cgp->cg_cgx).cs_nbfree--;
cylno = cbtocylno(fs, bno);
cgp->cg_b[cylno][cbtorpos(fs, bno)]--;
cgp->cg_btot[cylno]--;
fs->fs_fmod++;
return (cgp->cg_cgx * fs->fs_fpg + 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.
*/
ino_t
ialloccg(ip, cg, ipref, mode)
struct inode *ip;
int cg;
daddr_t ipref;
int mode;
{
register struct fs *fs;
register struct cg *cgp;
struct buf *bp;
int start, len, loc, map, i;
fs = ip->i_fs;
if (fs->fs_cs(fs, cg).cs_nifree == 0)
return (NULL);
bp = bread(ip->i_dev, fsbtodb(fs, cgtod(fs, cg)), (int)fs->fs_cgsize);
cgp = bp->b_un.b_cg;
if (bp->b_flags & B_ERROR || cgp->cg_magic != CG_MAGIC ||
cgp->cg_cs.cs_nifree == 0) {
brelse(bp);
return (NULL);
}
cgp->cg_time = time.tv_sec;
if (ipref) {
ipref %= fs->fs_ipg;
if (isclr(cgp->cg_iused, ipref))
goto gotit;
}
start = cgp->cg_irotor / NBBY;
len = howmany(fs->fs_ipg - cgp->cg_irotor, NBBY);
loc = skpc(0xff, len, &cgp->cg_iused[start]);
if (loc == 0) {
len = start + 1;
start = 0;
loc = skpc(0xff, len, &cgp->cg_iused[0]);
if (loc == 0) {
printf("cg = %s, irotor = %d, fs = %s\n",
cg, cgp->cg_irotor, fs->fs_fsmnt);
panic("ialloccg: map corrupted");
/* NOTREACHED */
}
}
i = start + len - loc;
map = cgp->cg_iused[i];
ipref = i * NBBY;
for (i = 1; i < (1 << NBBY); i <<= 1, ipref++) {
if ((map & i) == 0) {
cgp->cg_irotor = ipref;
goto gotit;
}
}
printf("fs = %s\n", fs->fs_fsmnt);
panic("ialloccg: block not in map");
/* NOTREACHED */
gotit:
setbit(cgp->cg_iused, ipref);
cgp->cg_cs.cs_nifree--;
fs->fs_cstotal.cs_nifree--;
fs->fs_cs(fs, cg).cs_nifree--;
fs->fs_fmod++;
if ((mode & IFMT) == IFDIR) {
cgp->cg_cs.cs_ndir++;
fs->fs_cstotal.cs_ndir++;
fs->fs_cs(fs, cg).cs_ndir++;
}
bdwrite(bp);
return (cg * fs->fs_ipg + ipref);
}
/*
* Free a block or fragment.
*
* The specified block or fragment is placed back in the
* free map. If a fragment is deallocated, a possible
* block reassembly is checked.
*/
free(ip, bno, size)
register struct inode *ip;
daddr_t bno;
off_t size;
{
register struct fs *fs;
register struct cg *cgp;
register struct buf *bp;
int cg, blk, frags, bbase;
register int i;
fs = ip->i_fs;
if ((unsigned)size > fs->fs_bsize || fragoff(fs, size) != 0) {
printf("dev = 0x%x, bsize = %d, size = %d, fs = %s\n",
ip->i_dev, fs->fs_bsize, size, fs->fs_fsmnt);
panic("free: bad size");
}
cg = dtog(fs, bno);
if (badblock(fs, bno)) {
printf("bad block %d, ino %d\n", bno, ip->i_number);
return;
}
bp = bread(ip->i_dev, fsbtodb(fs, cgtod(fs, cg)), (int)fs->fs_cgsize);
cgp = bp->b_un.b_cg;
if (bp->b_flags & B_ERROR || cgp->cg_magic != CG_MAGIC) {
brelse(bp);
return;
}
cgp->cg_time = time.tv_sec;
bno = dtogd(fs, bno);
if (size == fs->fs_bsize) {
if (isblock(fs, cgp->cg_free, fragstoblks(fs, bno))) {
printf("dev = 0x%x, block = %d, fs = %s\n",
ip->i_dev, bno, fs->fs_fsmnt);
panic("free: freeing free block");
}
setblock(fs, cgp->cg_free, fragstoblks(fs, bno));
cgp->cg_cs.cs_nbfree++;
fs->fs_cstotal.cs_nbfree++;
fs->fs_cs(fs, cg).cs_nbfree++;
i = cbtocylno(fs, bno);
cgp->cg_b[i][cbtorpos(fs, bno)]++;
cgp->cg_btot[i]++;
} else {
bbase = bno - fragnum(fs, bno);
/*
* decrement the counts associated with the old frags
*/
blk = blkmap(fs, cgp->cg_free, bbase);
fragacct(fs, blk, cgp->cg_frsum, -1);
/*
* deallocate the fragment
*/
frags = numfrags(fs, size);
for (i = 0; i < frags; i++) {
if (isset(cgp->cg_free, bno + i)) {
printf("dev = 0x%x, block = %d, fs = %s\n",
ip->i_dev, bno + i, fs->fs_fsmnt);
panic("free: freeing free frag");
}
setbit(cgp->cg_free, bno + i);
}
cgp->cg_cs.cs_nffree += i;
fs->fs_cstotal.cs_nffree += i;
fs->fs_cs(fs, cg).cs_nffree += i;
/*
* add back in counts associated with the new frags
*/
blk = blkmap(fs, cgp->cg_free, bbase);
fragacct(fs, blk, cgp->cg_frsum, 1);
/*
* if a complete block has been reassembled, account for it
*/
if (isblock(fs, cgp->cg_free, fragstoblks(fs, bbase))) {
cgp->cg_cs.cs_nffree -= fs->fs_frag;
fs->fs_cstotal.cs_nffree -= fs->fs_frag;
fs->fs_cs(fs, cg).cs_nffree -= fs->fs_frag;
cgp->cg_cs.cs_nbfree++;
fs->fs_cstotal.cs_nbfree++;
fs->fs_cs(fs, cg).cs_nbfree++;
i = cbtocylno(fs, bbase);
cgp->cg_b[i][cbtorpos(fs, bbase)]++;
cgp->cg_btot[i]++;
}
}
fs->fs_fmod++;
bdwrite(bp);
}
/*
* Free an inode.
*
* The specified inode is placed back in the free map.
*/
ifree(ip, ino, mode)
struct inode *ip;
ino_t ino;
int mode;
{
register struct fs *fs;
register struct cg *cgp;
register struct buf *bp;
int cg;
fs = ip->i_fs;
if ((unsigned)ino >= fs->fs_ipg*fs->fs_ncg) {
printf("dev = 0x%x, ino = %d, fs = %s\n",
ip->i_dev, ino, fs->fs_fsmnt);
panic("ifree: range");
}
cg = itog(fs, ino);
bp = bread(ip->i_dev, fsbtodb(fs, cgtod(fs, cg)), (int)fs->fs_cgsize);
cgp = bp->b_un.b_cg;
if (bp->b_flags & B_ERROR || cgp->cg_magic != CG_MAGIC) {
brelse(bp);
return;
}
cgp->cg_time = time.tv_sec;
ino %= fs->fs_ipg;
if (isclr(cgp->cg_iused, ino)) {
printf("dev = 0x%x, ino = %d, fs = %s\n",
ip->i_dev, ino, fs->fs_fsmnt);
panic("ifree: freeing free inode");
}
clrbit(cgp->cg_iused, ino);
if (ino < cgp->cg_irotor)
cgp->cg_irotor = ino;
cgp->cg_cs.cs_nifree++;
fs->fs_cstotal.cs_nifree++;
fs->fs_cs(fs, cg).cs_nifree++;
if ((mode & IFMT) == IFDIR) {
cgp->cg_cs.cs_ndir--;
fs->fs_cstotal.cs_ndir--;
fs->fs_cs(fs, cg).cs_ndir--;
}
fs->fs_fmod++;
bdwrite(bp);
}
/*
* Find a block of the specified size in the specified cylinder group.
*
* It is a panic if a request is made to find a block if none are
* available.
*/
daddr_t
mapsearch(fs, cgp, bpref, allocsiz)
register struct fs *fs;
register struct cg *cgp;
daddr_t bpref;
int allocsiz;
{
daddr_t bno;
int start, len, loc, i;
int blk, field, subfield, pos;
/*
* find the fragment by searching through the free block
* map for an appropriate bit pattern
*/
if (bpref)
start = dtogd(fs, bpref) / NBBY;
else
start = cgp->cg_frotor / NBBY;
len = howmany(fs->fs_fpg, NBBY) - start;
loc = scanc((unsigned)len, (caddr_t)&cgp->cg_free[start],
(caddr_t)fragtbl[fs->fs_frag],
(int)(1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
if (loc == 0) {
len = start + 1;
start = 0;
loc = scanc((unsigned)len, (caddr_t)&cgp->cg_free[0],
(caddr_t)fragtbl[fs->fs_frag],
(int)(1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
if (loc == 0) {
printf("start = %d, len = %d, fs = %s\n",
start, len, fs->fs_fsmnt);
panic("alloccg: map corrupted");
/* NOTREACHED */
}
}
bno = (start + len - loc) * NBBY;
cgp->cg_frotor = bno;
/*
* found the byte in the map
* sift through the bits to find the selected frag
*/
for (i = bno + NBBY; bno < i; bno += fs->fs_frag) {
blk = blkmap(fs, cgp->cg_free, bno);
blk <<= 1;
field = around[allocsiz];
subfield = inside[allocsiz];
for (pos = 0; pos <= fs->fs_frag - allocsiz; pos++) {
if ((blk & field) == subfield)
return (bno + pos);
field <<= 1;
subfield <<= 1;
}
}
printf("bno = %d, fs = %s\n", bno, fs->fs_fsmnt);
panic("alloccg: block not in map");
return (-1);
}
/*
* Fserr prints the name of a file system with an error diagnostic.
*
* The form of the error message is:
* fs: error message
*/
fserr(fs, cp)
struct fs *fs;
char *cp;
{
log(LOG_ERR, "%s: %s\n", fs->fs_fsmnt, cp);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.