/*
* 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.
*/
static daddr_t
ffs_alloccgblk(struct inode *ip, struct buf *bp, daddr_t bpref)
{
struct cg *cgp;
daddr_t blkno;
int32_t bno;
struct fs *fs = ip->i_fs;
const int needswap = UFS_FSNEEDSWAP(fs);
u_int8_t *blksfree_swap;
cgp = (struct cg *)bp->b_data;
blksfree_swap = cg_blksfree_swap(cgp, needswap);
if (bpref == 0 || (uint32_t)dtog(fs, bpref) != ufs_rw32(cgp->cg_cgx, needswap)) {
bpref = ufs_rw32(cgp->cg_rotor, needswap);
} else {
bpref = blknum(fs, bpref);
bno = dtogd(fs, bpref);
/*
* if the requested block is available, use it
*/
if (ffs_isblock(fs, blksfree_swap, fragstoblks(fs, bno)))
goto gotit;
}
/*
* Take the next available one in this cylinder group.
*/
bno = ffs_mapsearch(fs, cgp, bpref, (int)fs->fs_frag);
if (bno < 0)
return (0);
cgp->cg_rotor = ufs_rw32(bno, needswap);
gotit:
blkno = fragstoblks(fs, bno);
ffs_clrblock(fs, blksfree_swap, (long)blkno);
ffs_clusteracct(fs, cgp, blkno, -1);
ufs_add32(cgp->cg_cs.cs_nbfree, -1, needswap);
fs->fs_cstotal.cs_nbfree--;
fs->fs_cs(fs, ufs_rw32(cgp->cg_cgx, needswap)).cs_nbfree--;
fs->fs_fmod = 1;
blkno = ufs_rw32(cgp->cg_cgx, needswap) * fs->fs_fpg + bno;
return (blkno);
}
/*
* Initialize a cylinder group.
*/
static void
initcg(int cylno, time_t utime, const fsinfo_t *fsopts)
{
daddr_t cbase, dmax;
int32_t i, j, d, dlower, dupper, blkno;
struct ufs1_dinode *dp1;
struct ufs2_dinode *dp2;
int start;
/*
* Determine block bounds for cylinder group.
* Allow space for super block summary information in first
* cylinder group.
*/
cbase = cgbase(&sblock, cylno);
dmax = cbase + sblock.fs_fpg;
if (dmax > sblock.fs_size)
dmax = sblock.fs_size;
dlower = cgsblock(&sblock, cylno) - cbase;
dupper = cgdmin(&sblock, cylno) - cbase;
if (cylno == 0)
dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
memset(&acg, 0, sblock.fs_cgsize);
acg.cg_time = utime;
acg.cg_magic = CG_MAGIC;
acg.cg_cgx = cylno;
acg.cg_niblk = sblock.fs_ipg;
acg.cg_initediblk = MIN(sblock.fs_ipg, 2 * INOPB(&sblock));
acg.cg_ndblk = dmax - cbase;
if (sblock.fs_contigsumsize > 0)
acg.cg_nclusterblks = acg.cg_ndblk >> sblock.fs_fragshift;
start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
if (Oflag == 2) {
acg.cg_iusedoff = start;
} else {
if (cylno == sblock.fs_ncg - 1)
acg.cg_old_ncyl = howmany(acg.cg_ndblk,
sblock.fs_fpg / sblock.fs_old_cpg);
else
acg.cg_old_ncyl = sblock.fs_old_cpg;
acg.cg_old_time = acg.cg_time;
acg.cg_time = 0;
acg.cg_old_niblk = acg.cg_niblk;
acg.cg_niblk = 0;
acg.cg_initediblk = 0;
acg.cg_old_btotoff = start;
acg.cg_old_boff = acg.cg_old_btotoff +
sblock.fs_old_cpg * sizeof(int32_t);
acg.cg_iusedoff = acg.cg_old_boff +
sblock.fs_old_cpg * sizeof(u_int16_t);
}
acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
if (sblock.fs_contigsumsize <= 0) {
acg.cg_nextfreeoff = acg.cg_freeoff +
howmany(sblock.fs_fpg, CHAR_BIT);
} else {
acg.cg_clustersumoff = acg.cg_freeoff +
howmany(sblock.fs_fpg, CHAR_BIT) - sizeof(int32_t);
acg.cg_clustersumoff =
roundup(acg.cg_clustersumoff, sizeof(int32_t));
acg.cg_clusteroff = acg.cg_clustersumoff +
(sblock.fs_contigsumsize + 1) * sizeof(int32_t);
acg.cg_nextfreeoff = acg.cg_clusteroff +
howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
}
if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
printf("Panic: cylinder group too big\n");
exit(37);
}
acg.cg_cs.cs_nifree += sblock.fs_ipg;
if (cylno == 0)
for (i = 0; i < ROOTINO; i++) {
setbit(cg_inosused_swap(&acg, 0), i);
acg.cg_cs.cs_nifree--;
}
if (cylno > 0) {
/*
* In cylno 0, beginning space is reserved
* for boot and super blocks.
*/
for (d = 0, blkno = 0; d < dlower;) {
ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
if (sblock.fs_contigsumsize > 0)
setbit(cg_clustersfree_swap(&acg, 0), blkno);
acg.cg_cs.cs_nbfree++;
d += sblock.fs_frag;
blkno++;
}
}
if ((i = (dupper & (sblock.fs_frag - 1))) != 0) {
acg.cg_frsum[sblock.fs_frag - i]++;
for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
setbit(cg_blksfree_swap(&acg, 0), dupper);
acg.cg_cs.cs_nffree++;
}
}
for (d = dupper, blkno = dupper >> sblock.fs_fragshift;
d + sblock.fs_frag <= acg.cg_ndblk; ) {
setbit(cg_clustersfree_swap(&acg, 0), blkno);
acg.cg_cs.cs_nbfree++;
d += sblock.fs_frag;
blkno++;
}
}
if ((i = (dupper & (sblock.fs_frag - 1))) != 0) {
acg.cg_frsum[sblock.fs_frag - i]++;
for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
setbit(cg_blksfree_swap(&acg, 0), dupper);
acg.cg_cs.cs_nffree++;
}
}
for (d = dupper, blkno = dupper >> sblock.fs_fragshift;
d + sblock.fs_frag <= acg.cg_ndblk; ) {
ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
if (sblock.fs_contigsumsize > 0)
setbit(cg_clustersfree_swap(&acg, 0), blkno);
acg.cg_cs.cs_nbfree++;
d += sblock.fs_frag;
blkno++;
}
if (d < acg.cg_ndblk) {
acg.cg_frsum[acg.cg_ndblk - d]++;
for (; d < acg.cg_ndblk; d++) {
setbit(cg_blksfree_swap(&acg, 0), d);
acg.cg_cs.cs_nffree++;
}
}
if (sblock.fs_contigsumsize > 0) {
int32_t *sump = cg_clustersum_swap(&acg, 0);
/*
* 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.
*/
static int32_t
ffs_mapsearch(struct fs *fs, struct cg *cgp, daddr_t bpref, int allocsiz)
{
int32_t bno;
int start, len, loc, i;
int blk, field, subfield, pos;
int ostart, olen;
const int needswap = UFS_FSNEEDSWAP(fs);
/*
* find the fragment by searching through the free block
* map for an appropriate bit pattern
*/
if (bpref)
start = dtogd(fs, bpref) / NBBY;
else
start = ufs_rw32(cgp->cg_frotor, needswap) / NBBY;
len = howmany(fs->fs_fpg, NBBY) - start;
ostart = start;
olen = len;
loc = scanc((u_int)len,
(const u_char *)&cg_blksfree_swap(cgp, needswap)[start],
(const u_char *)fragtbl[fs->fs_frag],
(1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
if (loc == 0) {
len = start + 1;
start = 0;
loc = scanc((u_int)len,
(const u_char *)&cg_blksfree_swap(cgp, needswap)[0],
(const u_char *)fragtbl[fs->fs_frag],
(1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
if (loc == 0) {
errx(1,
"ffs_alloccg: map corrupted: start %d len %d offset %d %ld",
ostart, olen,
ufs_rw32(cgp->cg_freeoff, needswap),
(long)cg_blksfree_swap(cgp, needswap) - (long)cgp);
/* NOTREACHED */
}
}
bno = (start + len - loc) * NBBY;
cgp->cg_frotor = ufs_rw32(bno, needswap);
/*
* 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, cg_blksfree_swap(cgp, needswap), 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;
}
}
errx(1, "ffs_alloccg: block not in map: bno %lld", (long long)bno);
return (-1);
}
/*
* 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.
*/
void
ffs_blkfree(struct inode *ip, daddr_t bno, long size)
{
struct cg *cgp;
struct buf *bp;
int32_t fragno, cgbno;
int i, error, cg, blk, frags, bbase;
struct fs *fs = ip->i_fs;
const int needswap = UFS_FSNEEDSWAP(fs);
if (size > fs->fs_bsize || fragoff(fs, size) != 0 ||
fragnum(fs, bno) + numfrags(fs, size) > fs->fs_frag) {
errx(1, "blkfree: bad size: bno %lld bsize %d size %ld",
(long long)bno, fs->fs_bsize, size);
}
cg = dtog(fs, bno);
if (bno >= fs->fs_size) {
warnx("bad block %lld, ino %ju", (long long)bno,
(uintmax_t)ip->i_number);
return;
}
error = bread(ip->i_fd, ip->i_fs, fsbtodb(fs, cgtod(fs, cg)),
(int)fs->fs_cgsize, &bp);
if (error) {
brelse(bp);
return;
}
cgp = (struct cg *)bp->b_data;
if (!cg_chkmagic_swap(cgp, needswap)) {
brelse(bp);
return;
}
cgbno = dtogd(fs, bno);
if (size == fs->fs_bsize) {
fragno = fragstoblks(fs, cgbno);
if (!ffs_isfreeblock(fs, cg_blksfree_swap(cgp, needswap), fragno)) {
errx(1, "blkfree: freeing free block %lld",
(long long)bno);
}
ffs_setblock(fs, cg_blksfree_swap(cgp, needswap), fragno);
ffs_clusteracct(fs, cgp, fragno, 1);
ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap);
fs->fs_cstotal.cs_nbfree++;
fs->fs_cs(fs, cg).cs_nbfree++;
} else {
bbase = cgbno - fragnum(fs, cgbno);
/*
* decrement the counts associated with the old frags
*/
blk = blkmap(fs, cg_blksfree_swap(cgp, needswap), bbase);
ffs_fragacct_swap(fs, blk, cgp->cg_frsum, -1, needswap);
/*
* deallocate the fragment
*/
frags = numfrags(fs, size);
for (i = 0; i < frags; i++) {
if (isset(cg_blksfree_swap(cgp, needswap), cgbno + i)) {
errx(1, "blkfree: freeing free frag: block %lld",
(long long)(cgbno + i));
}
setbit(cg_blksfree_swap(cgp, needswap), cgbno + i);
}
ufs_add32(cgp->cg_cs.cs_nffree, i, needswap);
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, cg_blksfree_swap(cgp, needswap), bbase);
ffs_fragacct_swap(fs, blk, cgp->cg_frsum, 1, needswap);
/*
* if a complete block has been reassembled, account for it
*/
fragno = fragstoblks(fs, bbase);
if (ffs_isblock(fs, cg_blksfree_swap(cgp, needswap), fragno)) {
ufs_add32(cgp->cg_cs.cs_nffree, -fs->fs_frag, needswap);
fs->fs_cstotal.cs_nffree -= fs->fs_frag;
fs->fs_cs(fs, cg).cs_nffree -= fs->fs_frag;
ffs_clusteracct(fs, cgp, fragno, 1);
ufs_add32(cgp->cg_cs.cs_nbfree, 1, needswap);
fs->fs_cstotal.cs_nbfree++;
fs->fs_cs(fs, cg).cs_nbfree++;
}
}
fs->fs_fmod = 1;
bdwrite(bp);
}
/*
* 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
ffs_alloccg(struct inode *ip, int cg, daddr_t bpref, int size)
{
struct cg *cgp;
struct buf *bp;
daddr_t bno, blkno;
int error, frags, allocsiz, i;
struct fs *fs = ip->i_fs;
const int needswap = UFS_FSNEEDSWAP(fs);
if (fs->fs_cs(fs, cg).cs_nbfree == 0 && size == fs->fs_bsize)
return (0);
error = bread(ip->i_fd, ip->i_fs, fsbtodb(fs, cgtod(fs, cg)),
(int)fs->fs_cgsize, &bp);
if (error) {
brelse(bp);
return (0);
}
cgp = (struct cg *)bp->b_data;
if (!cg_chkmagic_swap(cgp, needswap) ||
(cgp->cg_cs.cs_nbfree == 0 && size == fs->fs_bsize)) {
brelse(bp);
return (0);
}
if (size == fs->fs_bsize) {
bno = ffs_alloccgblk(ip, bp, 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 (0);
}
bno = ffs_alloccgblk(ip, bp, bpref);
bpref = dtogd(fs, bno);
for (i = frags; i < fs->fs_frag; i++)
setbit(cg_blksfree_swap(cgp, needswap), bpref + i);
i = fs->fs_frag - frags;
ufs_add32(cgp->cg_cs.cs_nffree, i, needswap);
fs->fs_cstotal.cs_nffree += i;
fs->fs_cs(fs, cg).cs_nffree += i;
fs->fs_fmod = 1;
ufs_add32(cgp->cg_frsum[i], 1, needswap);
bdwrite(bp);
return (bno);
}
bno = ffs_mapsearch(fs, cgp, bpref, allocsiz);
for (i = 0; i < frags; i++)
clrbit(cg_blksfree_swap(cgp, needswap), bno + i);
ufs_add32(cgp->cg_cs.cs_nffree, -frags, needswap);
fs->fs_cstotal.cs_nffree -= frags;
fs->fs_cs(fs, cg).cs_nffree -= frags;
fs->fs_fmod = 1;
ufs_add32(cgp->cg_frsum[allocsiz], -1, needswap);
if (frags != allocsiz)
ufs_add32(cgp->cg_frsum[allocsiz - frags], 1, needswap);
blkno = cg * fs->fs_fpg + bno;
bdwrite(bp);
return blkno;
}
