/*- * modified for Lites 1.1 * * Aug 1995, Godmar Back (gback@cs.utah.edu) * University of Utah, Department of Computer Science */ /*- * 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. * 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 8.8 (Berkeley) 2/21/94 * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include static daddr_t ext2_alloccg(struct inode *, int, daddr_t, int); static daddr_t ext2_clusteralloc(struct inode *, int, daddr_t, int); static u_long ext2_dirpref(struct inode *); static void ext2_fserr(struct m_ext2fs *, uid_t, char *); static u_long ext2_hashalloc(struct inode *, int, long, int, daddr_t (*)(struct inode *, int, daddr_t, int)); static daddr_t ext2_nodealloccg(struct inode *, int, daddr_t, int); static daddr_t ext2_mapsearch(struct m_ext2fs *, char *, daddr_t); /* * Allocate a block in the filesystem. * * 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 ext2_alloc(struct inode *ip, int32_t lbn, int32_t bpref, int size, struct ucred *cred, int32_t *bnp) { struct m_ext2fs *fs; struct ext2mount *ump; int32_t bno; int cg; *bnp = 0; fs = ip->i_e2fs; ump = ip->i_ump; mtx_assert(EXT2_MTX(ump), MA_OWNED); #ifdef INVARIANTS if ((u_int)size > fs->e2fs_bsize || blkoff(fs, size) != 0) { vn_printf(ip->i_devvp, "bsize = %lu, size = %d, fs = %s\n", (long unsigned int)fs->e2fs_bsize, size, fs->e2fs_fsmnt); panic("ext2_alloc: bad size"); } if (cred == NOCRED) panic("ext2_alloc: missing credential"); #endif /* INVARIANTS */ if (size == fs->e2fs_bsize && fs->e2fs->e2fs_fbcount == 0) goto nospace; if (cred->cr_uid != 0 && fs->e2fs->e2fs_fbcount < fs->e2fs->e2fs_rbcount) 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)ext2_hashalloc(ip, cg, bpref, fs->e2fs_bsize, ext2_alloccg); if (bno > 0) { /* set next_alloc fields as done in block_getblk */ ip->i_next_alloc_block = lbn; ip->i_next_alloc_goal = bno; ip->i_blocks += btodb(fs->e2fs_bsize); ip->i_flag |= IN_CHANGE | IN_UPDATE; *bnp = bno; return (0); } nospace: EXT2_UNLOCK(ump); ext2_fserr(fs, cred->cr_uid, "filesystem full"); uprintf("\n%s: write failed, filesystem is full\n", fs->e2fs_fsmnt); return (ENOSPC); } /* * Reallocate a sequence of blocks into a contiguous sequence of blocks. * * The vnode and an array of buffer pointers for a range of sequential * logical blocks to be made contiguous is given. The allocator attempts * to find a range of sequential blocks starting as close as possible to * an fs_rotdelay offset from the end of the allocation for the logical * block immediately preceding the current range. If successful, the * physical block numbers in the buffer pointers and in the inode are * changed to reflect the new allocation. If unsuccessful, the allocation * is left unchanged. The success in doing the reallocation is returned. * Note that the error return is not reflected back to the user. Rather * the previous block allocation will be used. */ static SYSCTL_NODE(_vfs, OID_AUTO, ext2fs, CTLFLAG_RW, 0, "EXT2FS filesystem"); static int doasyncfree = 0; SYSCTL_INT(_vfs_ext2fs, OID_AUTO, doasyncfree, CTLFLAG_RW, &doasyncfree, 0, "Use asychronous writes to update block pointers when freeing blocks"); static int doreallocblks = 0; SYSCTL_INT(_vfs_ext2fs, OID_AUTO, doreallocblks, CTLFLAG_RW, &doreallocblks, 0, ""); int ext2_reallocblks(struct vop_reallocblks_args *ap) { struct m_ext2fs *fs; struct inode *ip; struct vnode *vp; struct buf *sbp, *ebp; uint32_t *bap, *sbap, *ebap = 0; struct ext2mount *ump; struct cluster_save *buflist; struct indir start_ap[NIADDR + 1], end_ap[NIADDR + 1], *idp; int32_t start_lbn, end_lbn, soff, newblk, blkno; int i, len, start_lvl, end_lvl, pref, ssize; if (doreallocblks == 0) return (ENOSPC); vp = ap->a_vp; ip = VTOI(vp); fs = ip->i_e2fs; ump = ip->i_ump; if (fs->e2fs_contigsumsize <= 0) return (ENOSPC); buflist = ap->a_buflist; len = buflist->bs_nchildren; start_lbn = buflist->bs_children[0]->b_lblkno; end_lbn = start_lbn + len - 1; #ifdef INVARIANTS for (i = 1; i < len; i++) if (buflist->bs_children[i]->b_lblkno != start_lbn + i) panic("ext2_reallocblks: non-cluster"); #endif /* * If the cluster crosses the boundary for the first indirect * block, leave space for the indirect block. Indirect blocks * are initially laid out in a position after the last direct * block. Block reallocation would usually destroy locality by * moving the indirect block out of the way to make room for * data blocks if we didn't compensate here. We should also do * this for other indirect block boundaries, but it is only * important for the first one. */ if (start_lbn < NDADDR && end_lbn >= NDADDR) return (ENOSPC); /* * If the latest allocation is in a new cylinder group, assume that * the filesystem has decided to move and do not force it back to * the previous cylinder group. */ if (dtog(fs, dbtofsb(fs, buflist->bs_children[0]->b_blkno)) != dtog(fs, dbtofsb(fs, buflist->bs_children[len - 1]->b_blkno))) return (ENOSPC); if (ext2_getlbns(vp, start_lbn, start_ap, &start_lvl) || ext2_getlbns(vp, end_lbn, end_ap, &end_lvl)) return (ENOSPC); /* * Get the starting offset and block map for the first block. */ if (start_lvl == 0) { sbap = &ip->i_db[0]; soff = start_lbn; } else { idp = &start_ap[start_lvl - 1]; if (bread(vp, idp->in_lbn, (int)fs->e2fs_bsize, NOCRED, &sbp)) { brelse(sbp); return (ENOSPC); } sbap = (int32_t *)sbp->b_data; soff = idp->in_off; } /* * If the block range spans two block maps, get the second map. */ if (end_lvl == 0 || (idp = &end_ap[end_lvl - 1])->in_off + 1 >= len) { ssize = len; } else { #ifdef INVARIANTS if (start_ap[start_lvl-1].in_lbn == idp->in_lbn) panic("ext2_reallocblks: start == end"); #endif ssize = len - (idp->in_off + 1); if (bread(vp, idp->in_lbn, (int)fs->e2fs_bsize, NOCRED, &ebp)) goto fail; ebap = (int32_t *)ebp->b_data; } /* * Find the preferred location for the cluster. */ EXT2_LOCK(ump); pref = ext2_blkpref(ip, start_lbn, soff, sbap, 0); /* * Search the block map looking for an allocation of the desired size. */ if ((newblk = (int32_t)ext2_hashalloc(ip, dtog(fs, pref), pref, len, ext2_clusteralloc)) == 0){ EXT2_UNLOCK(ump); goto fail; } /* * We have found a new contiguous block. * * First we have to replace the old block pointers with the new * block pointers in the inode and indirect blocks associated * with the file. */ #ifdef DEBUG printf("realloc: ino %d, lbns %jd-%jd\n\told:", ip->i_number, (intmax_t)start_lbn, (intmax_t)end_lbn); #endif /* DEBUG */ blkno = newblk; for (bap = &sbap[soff], i = 0; i < len; i++, blkno += fs->e2fs_fpb) { if (i == ssize) { bap = ebap; soff = -i; } #ifdef INVARIANTS if (buflist->bs_children[i]->b_blkno != fsbtodb(fs, *bap)) panic("ext2_reallocblks: alloc mismatch"); #endif #ifdef DEBUG printf(" %d,", *bap); #endif /* DEBUG */ *bap++ = blkno; } /* * Next we must write out the modified inode and indirect blocks. * For strict correctness, the writes should be synchronous since * the old block values may have been written to disk. In practise * they are almost never written, but if we are concerned about * strict correctness, the `doasyncfree' flag should be set to zero. * * The test on `doasyncfree' should be changed to test a flag * that shows whether the associated buffers and inodes have * been written. The flag should be set when the cluster is * started and cleared whenever the buffer or inode is flushed. * We can then check below to see if it is set, and do the * synchronous write only when it has been cleared. */ if (sbap != &ip->i_db[0]) { if (doasyncfree) bdwrite(sbp); else bwrite(sbp); } else { ip->i_flag |= IN_CHANGE | IN_UPDATE; if (!doasyncfree) ext2_update(vp, 1); } if (ssize < len) { if (doasyncfree) bdwrite(ebp); else bwrite(ebp); } /* * Last, free the old blocks and assign the new blocks to the buffers. */ #ifdef DEBUG printf("\n\tnew:"); #endif /* DEBUG */ for (blkno = newblk, i = 0; i < len; i++, blkno += fs->e2fs_fpb) { ext2_blkfree(ip, dbtofsb(fs, buflist->bs_children[i]->b_blkno), fs->e2fs_bsize); buflist->bs_children[i]->b_blkno = fsbtodb(fs, blkno); #ifdef DEBUG printf(" %d,", blkno); #endif /* DEBUG */ } #ifdef DEBUG printf("\n"); #endif /* DEBUG */ return (0); fail: if (ssize < len) brelse(ebp); if (sbap != &ip->i_db[0]) brelse(sbp); return (ENOSPC); } /* * Allocate an inode in the filesystem. * */ int ext2_valloc(struct vnode *pvp, int mode, struct ucred *cred, struct vnode **vpp) { struct timespec ts; struct inode *pip; struct m_ext2fs *fs; struct inode *ip; struct ext2mount *ump; ino_t ino, ipref; int i, error, cg; *vpp = NULL; pip = VTOI(pvp); fs = pip->i_e2fs; ump = pip->i_ump; EXT2_LOCK(ump); if (fs->e2fs->e2fs_ficount == 0) goto noinodes; /* * If it is a directory then obtain a cylinder group based on * ext2_dirpref else obtain it using ino_to_cg. The preferred inode is * always the next inode. */ if ((mode & IFMT) == IFDIR) { cg = ext2_dirpref(pip); if (fs->e2fs_contigdirs[cg] < 255) fs->e2fs_contigdirs[cg]++; } else { cg = ino_to_cg(fs, pip->i_number); if (fs->e2fs_contigdirs[cg] > 0) fs->e2fs_contigdirs[cg]--; } ipref = cg * fs->e2fs->e2fs_ipg + 1; ino = (ino_t)ext2_hashalloc(pip, cg, (long)ipref, mode, ext2_nodealloccg); if (ino == 0) goto noinodes; error = VFS_VGET(pvp->v_mount, ino, LK_EXCLUSIVE, vpp); if (error) { ext2_vfree(pvp, ino, mode); return (error); } ip = VTOI(*vpp); /* * The question is whether using VGET was such good idea at all: * Linux doesn't read the old inode in when it is allocating a * new one. I will set at least i_size and i_blocks to zero. */ ip->i_size = 0; ip->i_blocks = 0; ip->i_mode = 0; ip->i_flags = 0; /* now we want to make sure that the block pointers are zeroed out */ for (i = 0; i < NDADDR; i++) ip->i_db[i] = 0; for (i = 0; i < NIADDR; i++) ip->i_ib[i] = 0; /* * Set up a new generation number for this inode. * XXX check if this makes sense in ext2 */ if (ip->i_gen == 0 || ++ip->i_gen == 0) ip->i_gen = random() / 2 + 1; vfs_timestamp(&ts); ip->i_birthtime = ts.tv_sec; ip->i_birthnsec = ts.tv_nsec; /* printf("ext2_valloc: allocated inode %d\n", ino); */ return (0); noinodes: EXT2_UNLOCK(ump); ext2_fserr(fs, 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 allocate a * directory inode in the same cylinder group as its parent * directory, but also to reserve space for its files inodes * and data. Restrict the number of directories which may be * allocated one after another in the same cylinder group * without intervening allocation of files. * * If we allocate a first level directory then force allocation * in another cylinder group. * */ static u_long ext2_dirpref(struct inode *pip) { struct m_ext2fs *fs; int cg, prefcg, dirsize, cgsize; int avgifree, avgbfree, avgndir, curdirsize; int minifree, minbfree, maxndir; int mincg, minndir; int maxcontigdirs; mtx_assert(EXT2_MTX(pip->i_ump), MA_OWNED); fs = pip->i_e2fs; avgifree = fs->e2fs->e2fs_ficount / fs->e2fs_gcount; avgbfree = fs->e2fs->e2fs_fbcount / fs->e2fs_gcount; avgndir = fs->e2fs_total_dir / fs->e2fs_gcount; /* * Force allocation in another cg if creating a first level dir. */ ASSERT_VOP_LOCKED(ITOV(pip), "ext2fs_dirpref"); if (ITOV(pip)->v_vflag & VV_ROOT) { prefcg = arc4random() % fs->e2fs_gcount; mincg = prefcg; minndir = fs->e2fs_ipg; for (cg = prefcg; cg < fs->e2fs_gcount; cg++) if (fs->e2fs_gd[cg].ext2bgd_ndirs < minndir && fs->e2fs_gd[cg].ext2bgd_nifree >= avgifree && fs->e2fs_gd[cg].ext2bgd_nbfree >= avgbfree) { mincg = cg; minndir = fs->e2fs_gd[cg].ext2bgd_ndirs; } for (cg = 0; cg < prefcg; cg++) if (fs->e2fs_gd[cg].ext2bgd_ndirs < minndir && fs->e2fs_gd[cg].ext2bgd_nifree >= avgifree && fs->e2fs_gd[cg].ext2bgd_nbfree >= avgbfree) { mincg = cg; minndir = fs->e2fs_gd[cg].ext2bgd_ndirs; } return (mincg); } /* * Count various limits which used for * optimal allocation of a directory inode. */ maxndir = min(avgndir + fs->e2fs_ipg / 16, fs->e2fs_ipg); minifree = avgifree - avgifree / 4; if (minifree < 1) minifree = 1; minbfree = avgbfree - avgbfree / 4; if (minbfree < 1) minbfree = 1; cgsize = fs->e2fs_fsize * fs->e2fs_fpg; dirsize = AVGDIRSIZE; curdirsize = avgndir ? (cgsize - avgbfree * fs->e2fs_bsize) / avgndir : 0; if (dirsize < curdirsize) dirsize = curdirsize; if (dirsize <= 0) maxcontigdirs = 0; /* dirsize overflowed */ else maxcontigdirs = min((avgbfree * fs->e2fs_bsize) / dirsize, 255); maxcontigdirs = min(maxcontigdirs, fs->e2fs_ipg / AFPDIR); if (maxcontigdirs == 0) maxcontigdirs = 1; /* * Limit number of dirs in one cg and reserve space for * regular files, but only if we have no deficit in * inodes or space. */ prefcg = ino_to_cg(fs, pip->i_number); for (cg = prefcg; cg < fs->e2fs_gcount; cg++) if (fs->e2fs_gd[cg].ext2bgd_ndirs < maxndir && fs->e2fs_gd[cg].ext2bgd_nifree >= minifree && fs->e2fs_gd[cg].ext2bgd_nbfree >= minbfree) { if (fs->e2fs_contigdirs[cg] < maxcontigdirs) return (cg); } for (cg = 0; cg < prefcg; cg++) if (fs->e2fs_gd[cg].ext2bgd_ndirs < maxndir && fs->e2fs_gd[cg].ext2bgd_nifree >= minifree && fs->e2fs_gd[cg].ext2bgd_nbfree >= minbfree) { if (fs->e2fs_contigdirs[cg] < maxcontigdirs) return (cg); } /* * This is a backstop when we have deficit in space. */ for (cg = prefcg; cg < fs->e2fs_gcount; cg++) if (fs->e2fs_gd[cg].ext2bgd_nifree >= avgifree) return (cg); for (cg = 0; cg < prefcg; cg++) if (fs->e2fs_gd[cg].ext2bgd_nifree >= avgifree) break; return (cg); } /* * Select the desired position for the next block in a file. * * we try to mimic what Remy does in inode_getblk/block_getblk * * we note: blocknr == 0 means that we're about to allocate either * a direct block or a pointer block at the first level of indirection * (In other words, stuff that will go in i_db[] or i_ib[]) * * blocknr != 0 means that we're allocating a block that is none * of the above. Then, blocknr tells us the number of the block * that will hold the pointer */ int32_t ext2_blkpref(struct inode *ip, int32_t lbn, int indx, int32_t *bap, int32_t blocknr) { int tmp; mtx_assert(EXT2_MTX(ip->i_ump), MA_OWNED); /* if the next block is actually what we thought it is, then set the goal to what we thought it should be */ if (ip->i_next_alloc_block == lbn && ip->i_next_alloc_goal != 0) return ip->i_next_alloc_goal; /* now check whether we were provided with an array that basically tells us previous blocks to which we want to stay closeby */ if (bap) for (tmp = indx - 1; tmp >= 0; tmp--) if (bap[tmp]) return bap[tmp]; /* else let's fall back to the blocknr, or, if there is none, follow the rule that a block should be allocated near its inode */ return blocknr ? blocknr : (int32_t)(ip->i_block_group * EXT2_BLOCKS_PER_GROUP(ip->i_e2fs)) + ip->i_e2fs->e2fs->e2fs_first_dblock; } /* * 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 ext2_hashalloc(struct inode *ip, int cg, long pref, int size, daddr_t (*allocator)(struct inode *, int, daddr_t, int)) { struct m_ext2fs *fs; ino_t result; int i, icg = cg; mtx_assert(EXT2_MTX(ip->i_ump), MA_OWNED); 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_gcount; i *= 2) { cg += i; if (cg >= fs->e2fs_gcount) cg -= fs->e2fs_gcount; 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_gcount; for (i = 2; i < fs->e2fs_gcount; i++) { result = (*allocator)(ip, cg, 0, size); if (result) return (result); cg++; if (cg == fs->e2fs_gcount) 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 ext2_alloccg(struct inode *ip, int cg, daddr_t bpref, int size) { struct m_ext2fs *fs; struct buf *bp; struct ext2mount *ump; daddr_t bno, runstart, runlen; int bit, loc, end, error, start; char *bbp; /* XXX ondisk32 */ fs = ip->i_e2fs; ump = ip->i_ump; if (fs->e2fs_gd[cg].ext2bgd_nbfree == 0) return (0); EXT2_UNLOCK(ump); error = bread(ip->i_devvp, fsbtodb(fs, fs->e2fs_gd[cg].ext2bgd_b_bitmap), (int)fs->e2fs_bsize, NOCRED, &bp); if (error) { brelse(bp); EXT2_LOCK(ump); return (0); } if (fs->e2fs_gd[cg].ext2bgd_nbfree == 0) { /* * Another thread allocated the last block in this * group while we were waiting for the buffer. */ brelse(bp); EXT2_LOCK(ump); 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; retry: runlen = 0; runstart = 0; for (loc = start; loc < end; loc++) { if (bbp[loc] == (char)0xff) { runlen = 0; continue; } /* Start of a run, find the number of high clear bits. */ if (runlen == 0) { bit = fls(bbp[loc]); runlen = NBBY - bit; runstart = loc * NBBY + bit; } else if (bbp[loc] == 0) { /* Continue a run. */ runlen += NBBY; } else { /* * Finish the current run. If it isn't long * enough, start a new one. */ bit = ffs(bbp[loc]) - 1; runlen += bit; if (runlen >= 8) { bno = runstart; goto gotit; } /* Run was too short, start a new one. */ bit = fls(bbp[loc]); runlen = NBBY - bit; runstart = loc * NBBY + bit; } /* If the current run is long enough, use it. */ if (runlen >= 8) { bno = runstart; goto gotit; } } if (start != 0) { end = start; start = 0; goto retry; } bno = ext2_mapsearch(fs, bbp, bpref); if (bno < 0){ brelse(bp); EXT2_LOCK(ump); return (0); } gotit: #ifdef INVARIANTS if (isset(bbp, bno)) { printf("ext2fs_alloccgblk: cg=%d bno=%jd fs=%s\n", cg, (intmax_t)bno, fs->e2fs_fsmnt); panic("ext2fs_alloccg: dup alloc"); } #endif setbit(bbp, bno); EXT2_LOCK(ump); ext2_clusteracct(fs, bbp, cg, bno, -1); fs->e2fs->e2fs_fbcount--; fs->e2fs_gd[cg].ext2bgd_nbfree--; fs->e2fs_fmod = 1; EXT2_UNLOCK(ump); bdwrite(bp); return (cg * fs->e2fs->e2fs_fpg + fs->e2fs->e2fs_first_dblock + bno); } /* * Determine whether a cluster can be allocated. */ static daddr_t ext2_clusteralloc(struct inode *ip, int cg, daddr_t bpref, int len) { struct m_ext2fs *fs; struct ext2mount *ump; struct buf *bp; char *bbp; int bit, error, got, i, loc, run; int32_t *lp; daddr_t bno; fs = ip->i_e2fs; ump = ip->i_ump; if (fs->e2fs_maxcluster[cg] < len) return (0); EXT2_UNLOCK(ump); error = bread(ip->i_devvp, fsbtodb(fs, fs->e2fs_gd[cg].ext2bgd_b_bitmap), (int)fs->e2fs_bsize, NOCRED, &bp); if (error) goto fail_lock; bbp = (char *)bp->b_data; EXT2_LOCK(ump); /* * Check to see if a cluster of the needed size (or bigger) is * available in this cylinder group. */ lp = &fs->e2fs_clustersum[cg].cs_sum[len]; for (i = len; i <= fs->e2fs_contigsumsize; i++) if (*lp++ > 0) break; if (i > fs->e2fs_contigsumsize) { /* * Update the cluster summary information to reflect * the true maximum-sized cluster so that future cluster * allocation requests can avoid reading the bitmap only * to find no cluster. */ lp = &fs->e2fs_clustersum[cg].cs_sum[len - 1]; for (i = len - 1; i > 0; i--) if (*lp-- > 0) break; fs->e2fs_maxcluster[cg] = i; goto fail; } EXT2_UNLOCK(ump); /* Search the bitmap to find a big enough cluster like in FFS. */ if (dtog(fs, bpref) != cg) bpref = 0; if (bpref != 0) bpref = dtogd(fs, bpref); loc = bpref / NBBY; bit = 1 << (bpref % NBBY); for (run = 0, got = bpref; got < fs->e2fs->e2fs_fpg; got++) { if ((bbp[loc] & bit) != 0) run = 0; else { run++; if (run == len) break; } if ((got & (NBBY - 1)) != (NBBY - 1)) bit <<= 1; else { loc++; bit = 1; } } if (got >= fs->e2fs->e2fs_fpg) goto fail_lock; /* Allocate the cluster that we found. */ for (i = 1; i < len; i++) if (!isclr(bbp, got - run + i)) panic("ext2_clusteralloc: map mismatch"); bno = got - run + 1; if (bno >= fs->e2fs->e2fs_fpg) panic("ext2_clusteralloc: allocated out of group"); EXT2_LOCK(ump); for (i = 0; i < len; i += fs->e2fs_fpb) { setbit(bbp, bno + i); ext2_clusteracct(fs, bbp, cg, bno + i, -1); fs->e2fs->e2fs_fbcount--; fs->e2fs_gd[cg].ext2bgd_nbfree--; } fs->e2fs_fmod = 1; EXT2_UNLOCK(ump); bdwrite(bp); return (cg * fs->e2fs->e2fs_fpg + fs->e2fs->e2fs_first_dblock + bno); fail_lock: EXT2_LOCK(ump); fail: brelse(bp); return (0); } /* * Determine whether an inode can be allocated. * * Check to see if an inode is available, and if it is, * allocate it using tode in the specified cylinder group. */ static daddr_t ext2_nodealloccg(struct inode *ip, int cg, daddr_t ipref, int mode) { struct m_ext2fs *fs; struct buf *bp; struct ext2mount *ump; int error, start, len; char *ibp, *loc; ipref--; /* to avoid a lot of (ipref -1) */ if (ipref == -1) ipref = 0; fs = ip->i_e2fs; ump = ip->i_ump; if (fs->e2fs_gd[cg].ext2bgd_nifree == 0) return (0); EXT2_UNLOCK(ump); error = bread(ip->i_devvp, fsbtodb(fs, fs->e2fs_gd[cg].ext2bgd_i_bitmap), (int)fs->e2fs_bsize, NOCRED, &bp); if (error) { brelse(bp); EXT2_LOCK(ump); return (0); } if (fs->e2fs_gd[cg].ext2bgd_nifree == 0) { /* * Another thread allocated the last i-node in this * group while we were waiting for the buffer. */ brelse(bp); EXT2_LOCK(ump); 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 = memcchr(&ibp[start], 0xff, len); if (loc == NULL) { len = start + 1; start = 0; loc = memcchr(&ibp[start], 0xff, len); if (loc == NULL) { printf("cg = %d, ipref = %lld, fs = %s\n", cg, (long long)ipref, fs->e2fs_fsmnt); panic("ext2fs_nodealloccg: map corrupted"); /* NOTREACHED */ } } ipref = (loc - ibp) * NBBY + ffs(~*loc) - 1; gotit: setbit(ibp, ipref); EXT2_LOCK(ump); fs->e2fs_gd[cg].ext2bgd_nifree--; fs->e2fs->e2fs_ficount--; fs->e2fs_fmod = 1; if ((mode & IFMT) == IFDIR) { fs->e2fs_gd[cg].ext2bgd_ndirs++; fs->e2fs_total_dir++; } EXT2_UNLOCK(ump); bdwrite(bp); return (cg * fs->e2fs->e2fs_ipg + ipref +1); } /* * Free a block or fragment. * */ void ext2_blkfree(struct inode *ip, int32_t bno, long size) { struct m_ext2fs *fs; struct buf *bp; struct ext2mount *ump; int cg, error; char *bbp; fs = ip->i_e2fs; ump = ip->i_ump; 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); ext2_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, &bp); if (error) { brelse(bp); return; } bbp = (char *)bp->b_data; bno = dtogd(fs, bno); if (isclr(bbp, bno)) { printf("block = %lld, fs = %s\n", (long long)bno, fs->e2fs_fsmnt); panic("ext2_blkfree: freeing free block"); } clrbit(bbp, bno); EXT2_LOCK(ump); ext2_clusteracct(fs, bbp, cg, bno, 1); fs->e2fs->e2fs_fbcount++; fs->e2fs_gd[cg].ext2bgd_nbfree++; fs->e2fs_fmod = 1; EXT2_UNLOCK(ump); bdwrite(bp); } /* * Free an inode. * */ int ext2_vfree(struct vnode *pvp, ino_t ino, int mode) { struct m_ext2fs *fs; struct inode *pip; struct buf *bp; struct ext2mount *ump; int error, cg; char * ibp; pip = VTOI(pvp); fs = pip->i_e2fs; ump = pip->i_ump; if ((u_int)ino > fs->e2fs_ipg * fs->e2fs_gcount) panic("ext2_vfree: range: devvp = %p, ino = %ju, fs = %s", pip->i_devvp, (uintmax_t)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("ino = %llu, fs = %s\n", (unsigned long long)ino, fs->e2fs_fsmnt); if (fs->e2fs_ronly == 0) panic("ext2_vfree: freeing free inode"); } clrbit(ibp, ino); EXT2_LOCK(ump); fs->e2fs->e2fs_ficount++; fs->e2fs_gd[cg].ext2bgd_nifree++; if ((mode & IFMT) == IFDIR) { fs->e2fs_gd[cg].ext2bgd_ndirs--; fs->e2fs_total_dir--; } fs->e2fs_fmod = 1; EXT2_UNLOCK(ump); 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 ext2_mapsearch(struct m_ext2fs *fs, char *bbp, daddr_t bpref) { char *loc; int start, len; /* * 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 = memcchr(&bbp[start], 0xff, len); if (loc == NULL) { len = start + 1; start = 0; loc = memcchr(&bbp[start], 0xff, len); if (loc == NULL) { printf("start = %d, len = %d, fs = %s\n", start, len, fs->e2fs_fsmnt); panic("ext2_mapsearch: map corrupted"); /* NOTREACHED */ } } return ((loc - bbp) * NBBY + ffs(~*loc) - 1); } /* * Fserr prints the name of a filesystem with an error diagnostic. * * The form of the error message is: * fs: error message */ static void ext2_fserr(struct m_ext2fs *fs, uid_t uid, char *cp) { log(LOG_ERR, "uid %u on %s: %s\n", uid, fs->e2fs_fsmnt, cp); } int cg_has_sb(int i) { int a3, a5, a7; if (i == 0 || i == 1) return 1; for (a3 = 3, a5 = 5, a7 = 7; a3 <= i || a5 <= i || a7 <= i; a3 *= 3, a5 *= 5, a7 *= 7) if (i == a3 || i == a5 || i == a7) return 1; return 0; }