+/* ufs_alloc.c 6.2 83/09/28 */
+
+#include "../h/param.h"
+#include "../h/systm.h"
+#include "../h/mount.h"
+#include "../h/fs.h"
+#include "../h/conf.h"
+#include "../h/buf.h"
+#include "../h/inode.h"
+#include "../h/dir.h"
+#include "../h/user.h"
+#include "../h/quota.h"
+#include "../h/kernel.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;
+{
+ daddr_t bno;
+ register struct fs *fs;
+ register struct buf *bp, *obp;
+ int cg;
+
+ 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;
+ bno = (daddr_t)hashalloc(ip, cg, (long)bpref, nsize,
+ (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);
+ }
+ bp = getblk(ip->i_dev, fsbtodb(fs, bno), nsize);
+ bcopy(obp->b_un.b_addr, bp->b_un.b_addr, (u_int)osize);
+ bzero(bp->b_un.b_addr + osize, (unsigned)nsize - osize);
+ brelse(obp);
+ free(ip, bprev, (off_t)osize);
+ 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 maintaining a rotor that sweeps the cylinder groups. When a new
+ * group of blocks is needed, the rotor is advanced until a cylinder group
+ * with greater than the average number of free blocks is found.
+ *
+ * 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;
+ int cg, avgbfree;
+ 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.
+ */
+ avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
+ for (cg = fs->fs_cgrotor + 1; 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 <= fs->fs_cgrotor; 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 < nsize - osize)
+ return (NULL);
+ frags = numfrags(fs, nsize);
+ bbase = fragoff(fs, bprev);
+ if (bbase > (bprev + frags - 1) % fs->fs_frag) {
+ /* 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) {
+ brelse(bp);
+ return (NULL);
+ }
+ if (cgp->cg_cs.cs_nbfree == 0 && size == fs->fs_bsize)
+ 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)
+ 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 &= ~(fs->fs_frag - 1);
+ 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 buf *bp;
+ register struct cg *cgp;
+ int 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) {
+ brelse(bp);
+ return (NULL);
+ }
+ if (cgp->cg_cs.cs_nifree == 0)
+ return (NULL);
+ cgp->cg_time = time.tv_sec;
+ if (ipref) {
+ ipref %= fs->fs_ipg;
+ if (isclr(cgp->cg_iused, ipref))
+ goto gotit;
+ } else
+ ipref = cgp->cg_irotor;
+ for (i = 0; i < fs->fs_ipg; i++) {
+ ipref++;
+ if (ipref >= fs->fs_ipg)
+ ipref = 0;
+ if (isclr(cgp->cg_iused, ipref)) {
+ cgp->cg_irotor = ipref;
+ goto gotit;
+ }
+ }
+ brelse(bp);
+ return (NULL);
+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 - (bno % fs->fs_frag);
+ /*
+ * 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);
+ 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[start],
+ (caddr_t)fragtbl[fs->fs_frag],
+ (int)(1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
+ if (loc == 0)
+ return (-1);
+ }
+ 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;
+{
+
+ printf("%s: %s\n", fs->fs_fsmnt, cp);
+}
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