/* $NetBSD: resize_ffs.c,v 1.1 2003/02/21 04:08:55 jtk Exp $ */ /* From sources sent on February 17, 2003 */ /*- * As its sole author, I explicitly place this code in the public * domain. Anyone may use it for any purpose (though I would * appreciate credit where it is due). * * der Mouse * * mouse@rodents.montreal.qc.ca * 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B */ /* * ffs_resize: * * Resize a filesystem. Is capable of both growing and shrinking. * * Usage: fsresize filesystem newsize * * Example: fsresize /dev/rsd1e 29574 * * newsize is in DEV_BSIZE units (ie, disk sectors, usually 512 bytes * each). * * Note: this currently requires gcc to build, since it is written * depending on gcc-specific features, notably nested function * definitions (which in at least a few cases depend on the lexical * scoping gcc provides, so they can't be trivially moved outside). * * It will not do anything useful with filesystems in other than * host-native byte order. This really should be fixed (it's largely * a historical accident; the original version of this program is * older than bi-endian support in FFS). * * Many thanks go to John Kohl for finding bugs: the * one responsible for the "realloccgblk: can't find blk in cyl" * problem and a more minor one which left fs_dsize wrong when * shrinking. (These actually indicate bugs in fsck too - it should * have caught and fixed them.) * */ #include #include #include #include #include #include #include #include #include /* MAXFRAG */ #include /* ufs_daddr_t */ #include #include #include #include /* ufs_rw32 */ extern const char *__progname; /* Patchup for systems that don't yet have __progname */ #ifdef NO_PROGNAME const char *__progname; int main(int, char **); int main_(int, char **); int main(int ac, char **av) #define main main_ { __progname = av[0]; return (main(ac, av)); } #endif /* Suppress warnings about unused arguments */ #if defined(__GNUC__) && \ ( (__GNUC__ > 2) || \ ( (__GNUC__ == 2) && \ defined(__GNUC_MINOR__) && \ (__GNUC_MINOR__ >= 7) ) ) #define UNUSED_ARG(x) x __attribute__((__unused__)) #define INLINE inline #else #define UNUSED_ARG(x) x #define INLINE /**/ #endif /* new size of filesystem, in sectors */ static int newsize; /* fd open onto disk device */ static int fd; /* must we break up big I/O operations - see checksmallio() */ static int smallio; /* size of a cg, in bytes, rounded up to a frag boundary */ static int cgblksz; /* Superblocks. */ static struct fs *oldsb; /* before we started */ static struct fs *newsb; /* copy to work with */ /* Buffer to hold the above. Make sure it's aligned correctly. */ static char sbbuf[2 * SBSIZE] __attribute__((__aligned__(__alignof__(struct fs)))); /* a cg's worth of brand new squeaky-clean inodes */ static struct dinode *zinodes; /* pointers to the in-core cgs, read off disk and possibly modified */ static struct cg **cgs; /* pointer to csum array - the stuff pointed to on-disk by fs_csaddr */ static struct csum *csums; /* per-cg flags, indexed by cg number */ static unsigned char *cgflags; #define CGF_DIRTY 0x01 /* needs to be written to disk */ #define CGF_BLKMAPS 0x02 /* block bitmaps need rebuilding */ #define CGF_INOMAPS 0x04 /* inode bitmaps need rebuilding */ /* when shrinking, these two arrays record how we want blocks to move. */ /* if blkmove[i] is j, the frag that started out as frag #i should end */ /* up as frag #j. inomove[i]=j means, similarly, that the inode that */ /* started out as inode i should end up as inode j. */ static unsigned int *blkmove; static unsigned int *inomove; /* in-core copies of all inodes in the fs, indexed by inumber */ static struct dinode *inodes; /* per-inode flags, indexed by inumber */ static unsigned char *iflags; #define IF_DIRTY 0x01 /* needs to be written to disk */ #define IF_BDIRTY 0x02 /* like DIRTY, but is set on first inode in a * block of inodes, and applies to the whole * block. */ /* * See if we need to break up large I/O operations. This should never * be needed, but under at least one combination, * large enough disk transfers to the raw device hang. So if we're * talking to a character special device, play it safe; in this case, * readat() and writeat() break everything up into pieces no larger * than 8K, doing multiple syscalls for larger operations. */ static void checksmallio(void) { struct stat stb; fstat(fd, &stb); smallio = ((stb.st_mode & S_IFMT) == S_IFCHR); } /* * Read size bytes starting at blkno into buf. blkno is in DEV_BSIZE * units, ie, after fsbtodb(); size is in bytes. */ static void readat(off_t blkno, void *buf, int size) { /* Seek to the correct place. */ if (lseek(fd, blkno * DEV_BSIZE, L_SET) < 0) { fprintf(stderr, "%s: lseek: %s\n", __progname, strerror(errno)); exit(1); } /* See if we have to break up the transfer... */ if (smallio) { char *bp; /* pointer into buf */ int left; /* bytes left to go */ int n; /* number to do this time around */ int rv; /* syscall return value */ bp = buf; left = size; while (left > 0) { n = (left > 8192) ? 8192 : left; rv = read(fd, bp, n); if (rv < 0) { fprintf(stderr, "%s: read: %s\n", __progname, strerror(errno)); exit(1); } if (rv != n) { fprintf(stderr, "%s: read: wanted %d, got %d\n", __progname, n, rv); exit(1); } bp += n; left -= n; } } else { int rv; rv = read(fd, buf, size); if (rv < 0) { fprintf(stderr, "%s: read: %s\n", __progname, strerror(errno)); exit(1); } if (rv != size) { fprintf(stderr, "%s: read: wanted %d, got %d\n", __progname, size, rv); exit(1); } } } /* * Write size bytes from buf starting at blkno. blkno is in DEV_BSIZE * units, ie, after fsbtodb(); size is in bytes. */ static void writeat(off_t blkno, const void *buf, int size) { /* Seek to the correct place. */ if (lseek(fd, blkno * DEV_BSIZE, L_SET) < 0) { fprintf(stderr, "%s: lseek: %s\n", __progname, strerror(errno)); exit(1); } /* See if we have to break up the transfer... */ if (smallio) { const char *bp; /* pointer into buf */ int left; /* bytes left to go */ int n; /* number to do this time around */ int rv; /* syscall return value */ bp = buf; left = size; while (left > 0) { n = (left > 8192) ? 8192 : left; rv = write(fd, bp, n); if (rv < 0) { fprintf(stderr, "%s: write: %s\n", __progname, strerror(errno)); exit(1); } if (rv != n) { fprintf(stderr, "%s: write: wanted %d, got %d\n", __progname, n, rv); exit(1); } bp += n; left -= n; } } else { int rv; rv = write(fd, buf, size); if (rv < 0) { fprintf(stderr, "%s: write: %s\n", __progname, strerror(errno)); exit(1); } if (rv != size) { fprintf(stderr, "%s: write: wanted %d, got %d\n", __progname, size, rv); exit(1); } } } /* * Never-fail versions of malloc() and realloc(), and an allocation * routine (which also never fails) for allocating memory that will * never be freed until exit. */ /* * Never-fail malloc. */ static void * nfmalloc(size_t nb, const char *tag) { void *rv; rv = malloc(nb); if (rv) return (rv); fprintf(stderr, "%s: can't allocate %lu bytes for %s\n", __progname, (unsigned long int) nb, tag); exit(1); } /* * Never-fail realloc. */ static void * nfrealloc(void *blk, size_t nb, const char *tag) { void *rv; rv = realloc(blk, nb); if (rv) return (rv); fprintf(stderr, "%s: can't reallocate to %lu bytes for %s\n", __progname, (unsigned long int) nb, tag); exit(1); } /* * Allocate memory that will never be freed or reallocated. Arguably * this routine should handle small allocations by chopping up pages, * but that's not worth the bother; it's not called more than a * handful of times per run, and if the allocations are that small the * waste in giving each one its own page is ignorable. */ static void * alloconce(size_t nb, const char *tag) { void *rv; rv = mmap(0, nb, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0); if (rv != MAP_FAILED) return (rv); fprintf(stderr, "%s: can't allocate %lu bytes for %s\n", __progname, (unsigned long int) nb, tag); exit(1); } /* * Load the cgs and csums off disk. Also allocates the space to load * them into and initializes the per-cg flags. */ static void loadcgs(void) { int cg; char *cgp; cgblksz = roundup(oldsb->fs_cgsize, oldsb->fs_fsize); cgs = nfmalloc(oldsb->fs_ncg * sizeof(struct cg *), "cg pointers"); cgp = alloconce(oldsb->fs_ncg * cgblksz, "cgs"); cgflags = nfmalloc(oldsb->fs_ncg, "cg flags"); csums = nfmalloc(oldsb->fs_cssize, "cg summary"); for (cg = 0; cg < oldsb->fs_ncg; cg++) { cgs[cg] = (struct cg *) cgp; readat(fsbtodb(oldsb, cgtod(oldsb, cg)), cgp, cgblksz); cgflags[cg] = 0; cgp += cgblksz; } readat(fsbtodb(oldsb, oldsb->fs_csaddr), csums, oldsb->fs_cssize); } /* * Set n bits, starting with bit #base, in the bitmap pointed to by * bitvec (which is assumed to be large enough to include bits base * through base+n-1). */ static void set_bits(unsigned char *bitvec, unsigned int base, unsigned int n) { if (n < 1) return; /* nothing to do */ if (base & 7) { /* partial byte at beginning */ if (n <= 8 - (base & 7)) { /* entirely within one byte */ bitvec[base >> 3] |= (~((~0U) << n)) << (base & 7); return; } bitvec[base >> 3] |= (~0U) << (base & 7); n -= 8 - (base & 7); base = (base & ~7) + 8; } if (n >= 8) { /* do full bytes */ memset(bitvec + (base >> 3), 0xff, n >> 3); base += n & ~7; n &= 7; } if (n) { /* partial byte at end */ bitvec[base >> 3] |= ~((~0U) << n); } } /* * Clear n bits, starting with bit #base, in the bitmap pointed to by * bitvec (which is assumed to be large enough to include bits base * through base+n-1). Code parallels set_bits(). */ static void clr_bits(unsigned char *bitvec, int base, int n) { if (n < 1) return; if (base & 7) { if (n <= 8 - (base & 7)) { bitvec[base >> 3] &= ~((~((~0U) << n)) << (base & 7)); return; } bitvec[base >> 3] &= ~((~0U) << (base & 7)); n -= 8 - (base & 7); base = (base & ~7) + 8; } if (n >= 8) { bzero(bitvec + (base >> 3), n >> 3); base += n & ~7; n &= 7; } if (n) { bitvec[base >> 3] &= (~0U) << n; } } /* * Test whether bit #bit is set in the bitmap pointed to by bitvec. */ INLINE static int bit_is_set(unsigned char *bitvec, int bit) { return (bitvec[bit >> 3] & (1 << (bit & 7))); } /* * Test whether bit #bit is clear in the bitmap pointed to by bitvec. */ INLINE static int bit_is_clr(unsigned char *bitvec, int bit) { return (!bit_is_set(bitvec, bit)); } /* * Test whether a whole block of bits is set in a bitmap. This is * designed for testing (aligned) disk blocks in a bit-per-frag * bitmap; it has assumptions wired into it based on that, essentially * that the entire block fits into a single byte. This returns true * iff _all_ the bits are set; it is not just the complement of * blk_is_clr on the same arguments (unless blkfrags==1). */ INLINE static int blk_is_set(unsigned char *bitvec, int blkbase, int blkfrags) { unsigned int mask; mask = (~((~0U) << blkfrags)) << (blkbase & 7); return ((bitvec[blkbase >> 3] & mask) == mask); } /* * Test whether a whole block of bits is clear in a bitmap. See * blk_is_set (above) for assumptions. This returns true iff _all_ * the bits are clear; it is not just the complement of blk_is_set on * the same arguments (unless blkfrags==1). */ INLINE static int blk_is_clr(unsigned char *bitvec, int blkbase, int blkfrags) { unsigned int mask; mask = (~((~0U) << blkfrags)) << (blkbase & 7); return ((bitvec[blkbase >> 3] & mask) == 0); } /* * Initialize a new cg. Called when growing. Assumes memory has been * allocated but not otherwise set up. This code sets the fields of * the cg, initializes the bitmaps (and cluster summaries, if * applicable), updates both per-cylinder summary info and the global * summary info in newsb; it also writes out new inodes for the cg. * * This code knows it can never be called for cg 0, which makes it a * bit simpler than it would otherwise be. */ static void initcg(int cgn) { struct cg *cg; /* The in-core cg, of course */ int base; /* Disk address of cg base */ int dlow; /* Size of pre-cg data area */ int dhigh; /* Offset of post-inode data area, from base */ int dmax; /* Offset of end of post-inode data area */ int i; /* Generic loop index */ int n; /* Generic count */ cg = cgs[cgn]; /* Place the data areas */ base = cgbase(newsb, cgn); dlow = cgsblock(newsb, cgn) - base; dhigh = cgdmin(newsb, cgn) - base; dmax = newsb->fs_size - base; if (dmax > newsb->fs_fpg) dmax = newsb->fs_fpg; /* * Clear out the cg - assumes all-0-bytes is the correct way * to initialize fields we don't otherwise touch, which is * perhaps not the right thing to do, but it's what fsck and * mkfs do. */ bzero(cg, newsb->fs_cgsize); cg->cg_time = newsb->fs_time; cg->cg_magic = CG_MAGIC; cg->cg_cgx = cgn; cg->cg_ncyl = newsb->fs_cpg; /* fsck whines if the cg->cg_ncyl value in the last cg is fs_cpg * instead of zero, when fs_cpg is the correct value. */ /* XXX fix once fsck is fixed */ if ((cgn == newsb->fs_ncg - 1) /* && (newsb->fs_ncyl % newsb->fs_cpg) */ ) { cg->cg_ncyl = newsb->fs_ncyl % newsb->fs_cpg; } cg->cg_niblk = newsb->fs_ipg; cg->cg_ndblk = dmax; /* Set up the bitmap pointers. We have to be careful to lay out the * cg _exactly_ the way mkfs and fsck do it, since fsck compares the * _entire_ cg against a recomputed cg, and whines if there is any * mismatch, including the bitmap offsets. */ /* XXX update this comment when fsck is fixed */ cg->cg_btotoff = &cg->cg_space[0] - (unsigned char *) cg; cg->cg_boff = cg->cg_btotoff + (newsb->fs_cpg * sizeof(int32_t)); cg->cg_iusedoff = cg->cg_boff + (newsb->fs_cpg * newsb->fs_nrpos * sizeof(int16_t)); cg->cg_freeoff = cg->cg_iusedoff + howmany(newsb->fs_ipg, NBBY); if (newsb->fs_contigsumsize > 0) { cg->cg_nclusterblks = cg->cg_ndblk / newsb->fs_frag; cg->cg_clustersumoff = cg->cg_freeoff + howmany(newsb->fs_cpg * newsb->fs_spc / NSPF(newsb), NBBY) - sizeof(int32_t); cg->cg_clustersumoff = roundup(cg->cg_clustersumoff, sizeof(int32_t)); cg->cg_clusteroff = cg->cg_clustersumoff + ((newsb->fs_contigsumsize + 1) * sizeof(int32_t)); cg->cg_nextfreeoff = cg->cg_clusteroff + howmany(newsb->fs_cpg * newsb->fs_spc / NSPB(newsb), NBBY); n = dlow / newsb->fs_frag; if (n > 0) { set_bits(cg_clustersfree(cg, 0), 0, n); cg_clustersum(cg, 0)[(n > newsb->fs_contigsumsize) ? newsb->fs_contigsumsize : n]++; } } else { cg->cg_nextfreeoff = cg->cg_freeoff + howmany(newsb->fs_cpg * newsb->fs_spc / NSPF(newsb), NBBY); } /* Mark the data areas as free; everything else is marked busy by the * bzero up at the top. */ set_bits(cg_blksfree(cg, 0), 0, dlow); set_bits(cg_blksfree(cg, 0), dhigh, dmax - dhigh); /* Initialize summary info */ cg->cg_cs.cs_ndir = 0; cg->cg_cs.cs_nifree = newsb->fs_ipg; cg->cg_cs.cs_nbfree = dlow / newsb->fs_frag; cg->cg_cs.cs_nffree = 0; /* This is the simplest way of doing this; we perhaps could compute * the correct cg_blktot()[] and cg_blks()[] values other ways, but it * would be complicated and hardly seems worth the effort. (The * reason there isn't frag-at-beginning and frag-at-end code here, * like the code below for the post-inode data area, is that the * pre-sb data area always starts at 0, and thus is block-aligned, and * always ends at the sb, which is block-aligned.) */ for (i = 0; i < dlow; i += newsb->fs_frag) { cg_blktot(cg, 0)[cbtocylno(newsb, i)]++; cg_blks(newsb, cg, cbtocylno(newsb, i), 0)[cbtorpos(newsb, i)]++; } /* Deal with a partial block at the beginning of the post-inode area. * I'm not convinced this can happen - I think the inodes are always * block-aligned and always an integral number of blocks - but it's * cheap to do the right thing just in case. */ if (dhigh % newsb->fs_frag) { n = newsb->fs_frag - (dhigh % newsb->fs_frag); cg->cg_frsum[n]++; cg->cg_cs.cs_nffree += n; dhigh += n; } n = (dmax - dhigh) / newsb->fs_frag; /* We have n full-size blocks in the post-inode data area. */ if (n > 0) { cg->cg_cs.cs_nbfree += n; if (newsb->fs_contigsumsize > 0) { i = dhigh / newsb->fs_frag; set_bits(cg_clustersfree(cg, 0), i, n); cg_clustersum(cg, 0)[(n > newsb->fs_contigsumsize) ? newsb->fs_contigsumsize : n]++; } for (i = n; i > 0; i--) { cg_blktot(cg, 0)[cbtocylno(newsb, dhigh)]++; cg_blks(newsb, cg, cbtocylno(newsb, dhigh), 0)[cbtorpos(newsb, dhigh)]++; dhigh += newsb->fs_frag; } } /* Deal with any leftover frag at the end of the cg. */ i = dmax - dhigh; if (i) { cg->cg_frsum[i]++; cg->cg_cs.cs_nffree += i; } /* Update the csum info. */ csums[cgn] = cg->cg_cs; newsb->fs_cstotal.cs_nffree += cg->cg_cs.cs_nffree; newsb->fs_cstotal.cs_nbfree += cg->cg_cs.cs_nbfree; newsb->fs_cstotal.cs_nifree += cg->cg_cs.cs_nifree; /* Write out the cleared inodes. */ writeat(fsbtodb(newsb, cgimin(newsb, cgn)), zinodes, newsb->fs_ipg * sizeof(struct dinode)); /* Dirty the cg. */ cgflags[cgn] |= CGF_DIRTY; } /* * Find free space, at least nfrags consecutive frags of it. Pays no * attention to block boundaries, but refuses to straddle cg * boundaries, even if the disk blocks involved are in fact * consecutive. Return value is the frag number of the first frag of * the block, or -1 if no space was found. Uses newsb for sb values, * and assumes the cgs[] structures correctly describe the area to be * searched. * * XXX is there a bug lurking in the ignoring of block boundaries by * the routine used by fragmove() in evict_data()? Can an end-of-file * frag legally straddle a block boundary? If not, this should be * cloned and fixed to stop at block boundaries for that use. The * current one may still be needed for csum info motion, in case that * takes up more than a whole block (is the csum info allowed to begin * partway through a block and continue into the following block?). * * If we wrap off the end of the filesystem back to the beginning, we * can end up searching the end of the filesystem twice. I ignore * this inefficiency, since if that happens we're going to croak with * a no-space error anyway, so it happens at most once. */ static int find_freespace(unsigned int nfrags) { static int hand = 0; /* hand rotates through all frags in the fs */ int cgsize; /* size of the cg hand currently points into */ int cgn; /* number of cg hand currently points into */ int fwc; /* frag-within-cg number of frag hand points * to */ int run; /* length of run of free frags seen so far */ int secondpass; /* have we wrapped from end of fs to * beginning? */ unsigned char *bits; /* cg_blksfree()[] for cg hand points into */ cgn = dtog(newsb, hand); fwc = dtogd(newsb, hand); secondpass = (hand == 0); run = 0; bits = cg_blksfree(cgs[cgn], 0); cgsize = cgs[cgn]->cg_ndblk; while (1) { if (bit_is_set(bits, fwc)) { run++; if (run >= nfrags) return (hand + 1 - run); } else { run = 0; } hand++; fwc++; if (fwc >= cgsize) { fwc = 0; cgn++; if (cgn >= newsb->fs_ncg) { hand = 0; if (secondpass) return (-1); secondpass = 1; cgn = 0; } bits = cg_blksfree(cgs[cgn], 0); cgsize = cgs[cgn]->cg_ndblk; run = 0; } } } /* * Find a free block of disk space. Finds an entire block of frags, * all of which are free. Return value is the frag number of the * first frag of the block, or -1 if no space was found. Uses newsb * for sb values, and assumes the cgs[] structures correctly describe * the area to be searched. * * See find_freespace(), above, for remarks about hand wrapping around. */ static int find_freeblock(void) { static int hand = 0; /* hand rotates through all frags in fs */ int cgn; /* cg number of cg hand points into */ int fwc; /* frag-within-cg number of frag hand points * to */ int cgsize; /* size of cg hand points into */ int secondpass; /* have we wrapped from end to beginning? */ unsigned char *bits; /* cg_blksfree()[] for cg hand points into */ cgn = dtog(newsb, hand); fwc = dtogd(newsb, hand); secondpass = (hand == 0); bits = cg_blksfree(cgs[cgn], 0); cgsize = blknum(newsb, cgs[cgn]->cg_ndblk); while (1) { if (blk_is_set(bits, fwc, newsb->fs_frag)) return (hand); fwc += newsb->fs_frag; hand += newsb->fs_frag; if (fwc >= cgsize) { fwc = 0; cgn++; if (cgn >= newsb->fs_ncg) { hand = 0; if (secondpass) return (-1); secondpass = 1; cgn = 0; } bits = cg_blksfree(cgs[cgn], 0); cgsize = blknum(newsb, cgs[cgn]->cg_ndblk); } } } /* * Find a free inode, returning its inumber or -1 if none was found. * Uses newsb for sb values, and assumes the cgs[] structures * correctly describe the area to be searched. * * See find_freespace(), above, for remarks about hand wrapping around. */ static int find_freeinode(void) { static int hand = 0; /* hand rotates through all inodes in fs */ int cgn; /* cg number of cg hand points into */ int iwc; /* inode-within-cg number of inode hand points * to */ int secondpass; /* have we wrapped from end to beginning? */ unsigned char *bits; /* cg_inosused()[] for cg hand points into */ cgn = hand / newsb->fs_ipg; iwc = hand % newsb->fs_ipg; secondpass = (hand == 0); bits = cg_inosused(cgs[cgn], 0); while (1) { if (bit_is_clr(bits, iwc)) return (hand); hand++; iwc++; if (iwc >= newsb->fs_ipg) { iwc = 0; cgn++; if (cgn >= newsb->fs_ncg) { hand = 0; if (secondpass) return (-1); secondpass = 1; cgn = 0; } bits = cg_inosused(cgs[cgn], 0); } } } /* * Mark a frag as free. Sets the frag's bit in the cg_blksfree bitmap * for the appropriate cg, and marks the cg as dirty. */ static void free_frag(int fno) { int cgn; cgn = dtog(newsb, fno); set_bits(cg_blksfree(cgs[cgn], 0), dtogd(newsb, fno), 1); cgflags[cgn] |= CGF_DIRTY | CGF_BLKMAPS; } /* * Allocate a frag. Clears the frag's bit in the cg_blksfree bitmap * for the appropriate cg, and marks the cg as dirty. */ static void alloc_frag(int fno) { int cgn; cgn = dtog(newsb, fno); clr_bits(cg_blksfree(cgs[cgn], 0), dtogd(newsb, fno), 1); cgflags[cgn] |= CGF_DIRTY | CGF_BLKMAPS; } /* * Fix up the csum array. If shrinking, this involves freeing zero or * more frags; if growing, it involves allocating them, or if the * frags being grown into aren't free, finding space elsewhere for the * csum info. (If the number of occupied frags doesn't change, * nothing happens here.) */ static void csum_fixup(void) { int nold; /* # frags in old csum info */ int ntot; /* # frags in new csum info */ int nnew; /* ntot-nold */ int newloc; /* new location for csum info, if necessary */ int i; /* generic loop index */ int j; /* generic loop index */ int f; /* "from" frag number, if moving */ int t; /* "to" frag number, if moving */ int cgn; /* cg number, used when shrinking */ ntot = howmany(newsb->fs_cssize, newsb->fs_fsize); nold = howmany(oldsb->fs_cssize, newsb->fs_fsize); nnew = ntot - nold; /* First, if there's no change in frag counts, it's easy. */ if (nnew == 0) return; /* Next, if we're shrinking, it's almost as easy. Just free up any * frags in the old area we no longer need. */ if (nnew < 0) { for ((i = newsb->fs_csaddr + ntot - 1), (j = nnew); j < 0; i--, j++) { free_frag(i); } return; } /* We must be growing. Check to see that the new csum area fits * within the filesystem. I think this can never happen, since for * the csum area to grow, we must be adding at least one cg, so the * old csum area can't be this close to the end of the new filesystem. * But it's a cheap check. */ /* XXX what if csum info is at end of cg and grows into next cg, what * if it spills over onto the next cg's backup superblock? Can this * happen? */ if (newsb->fs_csaddr + ntot <= newsb->fs_size) { /* Okay, it fits - now, see if the space we want is free. */ for ((i = newsb->fs_csaddr + nold), (j = nnew); j > 0; i++, j--) { cgn = dtog(newsb, i); if (bit_is_clr(cg_blksfree(cgs[cgn], 0), dtogd(newsb, i))) break; } if (j <= 0) { /* Win win - all the frags we want are free. Allocate * 'em and we're all done. */ for ((i = newsb->fs_csaddr + ntot - nnew), (j = nnew); j > 0; i++, j--) { alloc_frag(i); } return; } } /* We have to move the csum info, sigh. Look for new space, free old * space, and allocate new. Update fs_csaddr. We don't copy anything * on disk at this point; the csum info will be written to the * then-current fs_csaddr as part of the final flush. */ newloc = find_freespace(ntot); if (newloc < 0) { printf("Sorry, no space available for new csums\n"); exit(1); } for (i = 0, f = newsb->fs_csaddr, t = newloc; i < ntot; i++, f++, t++) { if (i < nold) { free_frag(f); } alloc_frag(t); } newsb->fs_csaddr = newloc; } /* * Recompute newsb->fs_dsize. Just scans all cgs, adding the number of * data blocks in that cg to the total. */ static void recompute_fs_dsize(void) { int i; newsb->fs_dsize = 0; for (i = 0; i < newsb->fs_ncg; i++) { int dlow; /* size of before-sb data area */ int dhigh; /* offset of post-inode data area */ int dmax; /* total size of cg */ int base; /* base of cg, since cgsblock() etc add it in */ base = cgbase(newsb, i); dlow = cgsblock(newsb, i) - base; dhigh = cgdmin(newsb, i) - base; dmax = newsb->fs_size - base; if (dmax > newsb->fs_fpg) dmax = newsb->fs_fpg; newsb->fs_dsize += dlow + dmax - dhigh; } /* Space in cg 0 before cgsblock is boot area, not free space! */ newsb->fs_dsize -= cgsblock(newsb, 0) - cgbase(newsb, 0); /* And of course the csum info takes up space. */ newsb->fs_dsize -= howmany(newsb->fs_cssize, newsb->fs_fsize); } /* * Return the current time. We call this and assign, rather than * calling time() directly, as insulation against OSes where fs_time * is not a time_t. */ static time_t timestamp(void) { time_t t; time(&t); return (t); } /* * Grow the filesystem. */ static void grow(void) { int i; /* Update the timestamp. */ newsb->fs_time = timestamp(); /* Allocate and clear the new-inode area, in case we add any cgs. */ zinodes = alloconce(newsb->fs_ipg * sizeof(struct dinode), "zeroed inodes"); bzero(zinodes, newsb->fs_ipg * sizeof(struct dinode)); /* Update the size. */ newsb->fs_size = dbtofsb(newsb, newsize); /* Did we actually not grow? (This can happen if newsize is less than * a frag larger than the old size - unlikely, but no excuse to * misbehave if it happens.) */ if (newsb->fs_size == oldsb->fs_size) return; /* Check that the new last sector (frag, actually) is writable. Since * it's at least one frag larger than it used to be, we know we aren't * overwriting anything important by this. (The choice of sbbuf as * what to write is irrelevant; it's just something handy that's known * to be at least one frag in size.) */ writeat(newsb->fs_size - 1, &sbbuf, newsb->fs_fsize); /* Update fs_ncyl and fs_ncg. */ newsb->fs_ncyl = (newsb->fs_size * NSPF(newsb)) / newsb->fs_spc; newsb->fs_ncg = howmany(newsb->fs_ncyl, newsb->fs_cpg); /* Does the last cg end before the end of its inode area? There is no * reason why this couldn't be handled, but it would complicate a lot * of code (in all filesystem code - fsck, kernel, etc) because of the * potential partial inode area, and the gain in space would be * minimal, at most the pre-sb data area. */ if (cgdmin(newsb, newsb->fs_ncg - 1) > newsb->fs_size) { newsb->fs_ncg--; newsb->fs_ncyl = newsb->fs_ncg * newsb->fs_cpg; newsb->fs_size = (newsb->fs_ncyl * newsb->fs_spc) / NSPF(newsb); printf("Warning: last cylinder group is too small;\n"); printf(" dropping it. New size = %lu.\n", (unsigned long int) fsbtodb(newsb, newsb->fs_size)); } /* Find out how big the csum area is, and realloc csums if bigger. */ newsb->fs_cssize = fragroundup(newsb, newsb->fs_ncg * sizeof(struct csum)); if (newsb->fs_cssize > oldsb->fs_cssize) csums = nfrealloc(csums, newsb->fs_cssize, "new cg summary"); /* If we're adding any cgs, realloc structures and set up the new cgs. */ if (newsb->fs_ncg > oldsb->fs_ncg) { char *cgp; cgs = nfrealloc(cgs, newsb->fs_ncg * sizeof(struct cg *), "cg pointers"); cgflags = nfrealloc(cgflags, newsb->fs_ncg, "cg flags"); bzero(cgflags + oldsb->fs_ncg, newsb->fs_ncg - oldsb->fs_ncg); cgp = alloconce((newsb->fs_ncg - oldsb->fs_ncg) * cgblksz, "cgs"); for (i = oldsb->fs_ncg; i < newsb->fs_ncg; i++) { cgs[i] = (struct cg *) cgp; initcg(i); cgp += cgblksz; } cgs[oldsb->fs_ncg - 1]->cg_ncyl = oldsb->fs_cpg; cgflags[oldsb->fs_ncg - 1] |= CGF_DIRTY; } /* If the old fs ended partway through a cg, we have to update the old * last cg (though possibly not to a full cg!). */ if (oldsb->fs_size % oldsb->fs_fpg) { struct cg *cg; int newcgsize; int prevcgtop; int oldcgsize; cg = cgs[oldsb->fs_ncg - 1]; cgflags[oldsb->fs_ncg - 1] |= CGF_DIRTY | CGF_BLKMAPS; prevcgtop = oldsb->fs_fpg * (oldsb->fs_ncg - 1); newcgsize = newsb->fs_size - prevcgtop; if (newcgsize > newsb->fs_fpg) newcgsize = newsb->fs_fpg; oldcgsize = oldsb->fs_size % oldsb->fs_fpg; set_bits(cg_blksfree(cg, 0), oldcgsize, newcgsize - oldcgsize); cg->cg_ncyl = howmany(newcgsize * NSPF(newsb), newsb->fs_spc); cg->cg_ndblk = newcgsize; } /* Fix up the csum info, if necessary. */ csum_fixup(); /* Make fs_dsize match the new reality. */ recompute_fs_dsize(); } /* * Call (*fn)() for each inode, passing the inode and its inumber. The * number of cylinder groups is pased in, so this can be used to map * over either the old or the new filesystem's set of inodes. */ static void map_inodes(void (*fn) (struct dinode * di, unsigned int, void *arg), int ncg, void *cbarg) { int i; int ni; ni = oldsb->fs_ipg * ncg; for (i = 0; i < ni; i++) (*fn) (inodes + i, i, cbarg); } /* Values for the third argument to the map function for * map_inode_data_blocks. MDB_DATA indicates the block is contains * file data; MDB_INDIR_PRE and MDB_INDIR_POST indicate that it's an * indirect block. The MDB_INDIR_PRE call is made before the indirect * block pointers are followed and the pointed-to blocks scanned, * MDB_INDIR_POST after. */ #define MDB_DATA 1 #define MDB_INDIR_PRE 2 #define MDB_INDIR_POST 3 typedef void (*mark_callback_t) (unsigned int blocknum, unsigned int nfrags, unsigned int blksize, int opcode); /* Helper function - handles a data block. Calls the callback * function and returns number of bytes occupied in file (actually, * rounded up to a frag boundary). The name is historical. */ static int markblk(mark_callback_t fn, struct dinode * di, int bn, off_t o) { int sz; int nb; if (o >= di->di_size) return (0); sz = dblksize(newsb, di, lblkno(newsb, o)); nb = (sz > di->di_size - o) ? di->di_size - o : sz; if (bn) (*fn) (bn, numfrags(newsb, sz), nb, MDB_DATA); return (sz); } /* Helper function - handles an indirect block. Makes the * MDB_INDIR_PRE callback for the indirect block, loops over the * pointers and recurses, and makes the MDB_INDIR_POST callback. * Returns the number of bytes occupied in file, as does markblk(). * For the sake of update_for_data_move(), we read the indirect block * _after_ making the _PRE callback. The name is historical. */ static int markiblk(mark_callback_t fn, struct dinode * di, int bn, off_t o, int lev) { int i; int j; int tot; static daddr_t indirblk1[howmany(MAXBSIZE, sizeof(daddr_t))]; static daddr_t indirblk2[howmany(MAXBSIZE, sizeof(daddr_t))]; static daddr_t indirblk3[howmany(MAXBSIZE, sizeof(daddr_t))]; static daddr_t *indirblks[3] = { &indirblk1[0], &indirblk2[0], &indirblk3[0] }; if (lev < 0) return (markblk(fn, di, bn, o)); if (bn == 0) { for (i = newsb->fs_bsize; lev >= 0; i *= NINDIR(newsb), lev--); return (i); } (*fn) (bn, newsb->fs_frag, newsb->fs_bsize, MDB_INDIR_PRE); readat(fsbtodb(newsb, bn), indirblks[lev], newsb->fs_bsize); tot = 0; for (i = 0; i < NINDIR(newsb); i++) { j = markiblk(fn, di, indirblks[lev][i], o, lev - 1); if (j == 0) break; o += j; tot += j; } (*fn) (bn, newsb->fs_frag, newsb->fs_bsize, MDB_INDIR_POST); return (tot); } /* * Call (*fn)() for each data block for an inode. This routine assumes * the inode is known to be of a type that has data blocks (file, * directory, or non-fast symlink). The called function is: * * (*fn)(unsigned int blkno, unsigned int nf, unsigned int nb, int op) * * where blkno is the frag number, nf is the number of frags starting * at blkno (always <= fs_frag), nb is the number of bytes that belong * to the file (usually nf*fs_frag, often less for the last block/frag * of a file). */ static void map_inode_data_blocks(struct dinode * di, mark_callback_t fn) { off_t o; /* offset within inode */ int inc; /* increment for o - maybe should be off_t? */ int b; /* index within di_db[] and di_ib[] arrays */ /* Scan the direct blocks... */ o = 0; for (b = 0; b < NDADDR; b++) { inc = markblk(fn, di, di->di_db[b], o); if (inc == 0) break; o += inc; } /* ...and the indirect blocks. */ if (inc) { for (b = 0; b < NIADDR; b++) { inc = markiblk(fn, di, di->di_ib[b], o, b); if (inc == 0) return; o += inc; } } } static void dblk_callback(struct dinode * di, unsigned int inum, void *arg) { mark_callback_t fn; fn = (mark_callback_t) arg; switch (di->di_mode & IFMT) { case IFLNK: if (di->di_size > newsb->fs_maxsymlinklen) { case IFDIR: case IFREG: map_inode_data_blocks(di, fn); } break; } } /* * Make a callback call, a la map_inode_data_blocks, for all data * blocks in the entire fs. This is used only once, in * update_for_data_move, but it's out at top level because the complex * downward-funarg nesting that would otherwise result seems to give * gcc gastric distress. */ static void map_data_blocks(mark_callback_t fn, int ncg) { map_inodes(&dblk_callback, ncg, (void *) fn); } /* * Initialize the blkmove array. */ static void blkmove_init(void) { int i; blkmove = alloconce(oldsb->fs_size * sizeof(*blkmove), "blkmove"); for (i = 0; i < oldsb->fs_size; i++) blkmove[i] = i; } /* * Load the inodes off disk. Allocates the structures and initializes * them - the inodes from disk, the flags to zero. */ static void loadinodes(void) { int cg; struct dinode *iptr; inodes = alloconce(oldsb->fs_ncg * oldsb->fs_ipg * sizeof(struct dinode), "inodes"); iflags = alloconce(oldsb->fs_ncg * oldsb->fs_ipg, "inode flags"); bzero(iflags, oldsb->fs_ncg * oldsb->fs_ipg); iptr = inodes; for (cg = 0; cg < oldsb->fs_ncg; cg++) { readat(fsbtodb(oldsb, cgimin(oldsb, cg)), iptr, oldsb->fs_ipg * sizeof(struct dinode)); iptr += oldsb->fs_ipg; } } /* * Report a filesystem-too-full problem. */ static void toofull(void) { printf("Sorry, would run out of data blocks\n"); exit(1); } /* * Record a desire to move "n" frags from "from" to "to". */ static void mark_move(unsigned int from, unsigned int to, unsigned int n) { for (; n > 0; n--) blkmove[from++] = to++; } /* Helper function - evict n frags, starting with start (cg-relative). * The free bitmap is scanned, unallocated frags are ignored, and * each block of consecutive allocated frags is moved as a unit. */ static void fragmove(struct cg * cg, int base, unsigned int start, unsigned int n) { int i; int run; run = 0; for (i = 0; i <= n; i++) { if ((i < n) && bit_is_clr(cg_blksfree(cg, 0), start + i)) { run++; } else { if (run > 0) { int off; off = find_freespace(run); if (off < 0) toofull(); mark_move(base + start + i - run, off, run); set_bits(cg_blksfree(cg, 0), start + i - run, run); clr_bits(cg_blksfree(cgs[dtog(oldsb, off)], 0), dtogd(oldsb, off), run); } run = 0; } } } /* * Evict all data blocks from the given cg, starting at minfrag (based * at the beginning of the cg), for length nfrag. The eviction is * assumed to be entirely data-area; this should not be called with a * range overlapping the metadata structures in the cg. It also * assumes minfrag points into the given cg; it will misbehave if this * is not true. * * See the comment header on find_freespace() for one possible bug * lurking here. */ static void evict_data(struct cg * cg, unsigned int minfrag, unsigned int nfrag) { int base; /* base of cg (in frags from beginning of fs) */ base = cgbase(oldsb, cg->cg_cgx); /* Does the boundary fall in the middle of a block? To avoid breaking * between frags allocated as consecutive, we always evict the whole * block in this case, though one could argue we should check to see * if the frag before or after the break is unallocated. */ if (minfrag % oldsb->fs_frag) { int n; n = minfrag % oldsb->fs_frag; minfrag -= n; nfrag += n; } /* Do whole blocks. If a block is wholly free, skip it; if wholly * allocated, move it in toto. If neither, call fragmove() to move * the frags to new locations. */ while (nfrag >= oldsb->fs_frag) { if (!blk_is_set(cg_blksfree(cg, 0), minfrag, oldsb->fs_frag)) { if (blk_is_clr(cg_blksfree(cg, 0), minfrag, oldsb->fs_frag)) { int off; off = find_freeblock(); if (off < 0) toofull(); mark_move(base + minfrag, off, oldsb->fs_frag); set_bits(cg_blksfree(cg, 0), minfrag, oldsb->fs_frag); clr_bits(cg_blksfree(cgs[dtog(oldsb, off)], 0), dtogd(oldsb, off), oldsb->fs_frag); } else { fragmove(cg, base, minfrag, oldsb->fs_frag); } } minfrag += oldsb->fs_frag; nfrag -= oldsb->fs_frag; } /* Clean up any sub-block amount left over. */ if (nfrag) { fragmove(cg, base, minfrag, nfrag); } } /* * Move all data blocks according to blkmove. We have to be careful, * because we may be updating indirect blocks that will themselves be * getting moved, or inode daddr_t arrays that point to indirect * blocks that will be moved. We call this before * update_for_data_move, and update_for_data_move does inodes first, * then indirect blocks in preorder, so as to make sure that the * filesystem is self-consistent at all points, for better crash * tolerance. (We can get away with this only because all the writes * done by perform_data_move() are writing into space that's not used * by the old filesystem.) If we crash, some things may point to the * old data and some to the new, but both copies are the same. The * only wrong things should be csum info and free bitmaps, which fsck * is entirely capable of cleaning up. * * Since blkmove_init() initializes all blocks to move to their current * locations, we can have two blocks marked as wanting to move to the * same location, but only two and only when one of them is the one * that was already there. So if blkmove[i]==i, we ignore that entry * entirely - for unallocated blocks, we don't want it (and may be * putting something else there), and for allocated blocks, we don't * want to copy it anywhere. */ static void perform_data_move(void) { int i; int run; int maxrun; char buf[65536]; maxrun = sizeof(buf) / newsb->fs_fsize; run = 0; for (i = 0; i < oldsb->fs_size; i++) { if ((blkmove[i] == i) || (run >= maxrun) || ((run > 0) && (blkmove[i] != blkmove[i - 1] + 1))) { if (run > 0) { readat(fsbtodb(oldsb, i - run), &buf[0], run << oldsb->fs_fshift); writeat(fsbtodb(oldsb, blkmove[i - run]), &buf[0], run << oldsb->fs_fshift); } run = 0; } if (blkmove[i] != i) run++; } if (run > 0) { readat(fsbtodb(oldsb, i - run), &buf[0], run << oldsb->fs_fshift); writeat(fsbtodb(oldsb, blkmove[i - run]), &buf[0], run << oldsb->fs_fshift); } } /* * This modifies an array of daddr_t, according to blkmove. This is * used to update inode block arrays and indirect blocks to point to * the new locations of data blocks. * * Return value is the number of daddr_ts that needed updating; in * particular, the return value is zero iff nothing was modified. */ static int movemap_blocks(daddr_t * vec, int n) { int rv; rv = 0; for (; n > 0; n--, vec++) { if (blkmove[*vec] != *vec) { *vec = blkmove[*vec]; rv++; } } return (rv); } static void moveblocks_callback(struct dinode * di, unsigned int inum, void *arg) { switch (di->di_mode & IFMT) { case IFLNK: if (di->di_size > oldsb->fs_maxsymlinklen) { case IFDIR: case IFREG: /* don't || these two calls; we need their * side-effects */ if (movemap_blocks(&di->di_db[0], NDADDR)) { iflags[inum] |= IF_DIRTY; } if (movemap_blocks(&di->di_ib[0], NIADDR)) { iflags[inum] |= IF_DIRTY; } } break; } } static void moveindir_callback(unsigned int off, unsigned int nfrag, unsigned int nbytes, int kind) { if (kind == MDB_INDIR_PRE) { daddr_t blk[howmany(MAXBSIZE, sizeof(daddr_t))]; readat(fsbtodb(oldsb, off), &blk[0], oldsb->fs_bsize); if (movemap_blocks(&blk[0], NINDIR(oldsb))) { writeat(fsbtodb(oldsb, off), &blk[0], oldsb->fs_bsize); } } } /* * Update all inode data arrays and indirect blocks to point to the new * locations of data blocks. See the comment header on * perform_data_move for some ordering considerations. */ static void update_for_data_move(void) { map_inodes(&moveblocks_callback, oldsb->fs_ncg, NULL); map_data_blocks(&moveindir_callback, oldsb->fs_ncg); } /* * Initialize the inomove array. */ static void inomove_init(void) { int i; inomove = alloconce(oldsb->fs_ipg * oldsb->fs_ncg * sizeof(*inomove), "inomove"); for (i = (oldsb->fs_ipg * oldsb->fs_ncg) - 1; i >= 0; i--) inomove[i] = i; } /* * Flush all dirtied inodes to disk. Scans the inode flags array; for * each dirty inode, it sets the BDIRTY bit on the first inode in the * block containing the dirty inode. Then it scans by blocks, and for * each marked block, writes it. */ static void flush_inodes(void) { int i; int ni; int m; ni = newsb->fs_ipg * newsb->fs_ncg; m = INOPB(newsb) - 1; for (i = 0; i < ni; i++) { if (iflags[i] & IF_DIRTY) { iflags[i & ~m] |= IF_BDIRTY; } } m++; for (i = 0; i < ni; i += m) { if (iflags[i] & IF_BDIRTY) { writeat(fsbtodb(newsb, ino_to_fsba(newsb, i)), inodes + i, newsb->fs_bsize); } } } /* * Evict all inodes from the specified cg. shrink() already checked * that there were enough free inodes, so the no-free-inodes check is * a can't-happen. If it does trip, the filesystem should be in good * enough shape for fsck to fix; see the comment on perform_data_move * for the considerations in question. */ static void evict_inodes(struct cg * cg) { int inum; int i; int fi; inum = newsb->fs_ipg * cg->cg_cgx; for (i = 0; i < newsb->fs_ipg; i++, inum++) { if (inodes[inum].di_mode != 0) { fi = find_freeinode(); if (fi < 0) { printf("Sorry, inodes evaporated - " "filesystem probably needs fsck\n"); exit(1); } inomove[inum] = fi; clr_bits(cg_inosused(cg, 0), i, 1); set_bits(cg_inosused(cgs[ino_to_cg(newsb, fi)], 0), fi % newsb->fs_ipg, 1); } } } /* * Move inodes from old locations to new. Does not actually write * anything to disk; just copies in-core and sets dirty bits. * * We have to be careful here for reasons similar to those mentioned in * the comment header on perform_data_move, above: for the sake of * crash tolerance, we want to make sure everything is present at both * old and new locations before we update pointers. So we call this * first, then flush_inodes() to get them out on disk, then update * directories to match. */ static void perform_inode_move(void) { int i; int ni; ni = oldsb->fs_ipg * oldsb->fs_ncg; for (i = 0; i < ni; i++) { if (inomove[i] != i) { inodes[inomove[i]] = inodes[i]; iflags[inomove[i]] = iflags[i] | IF_DIRTY; } } } /* * Update the directory contained in the nb bytes at buf, to point to * inodes' new locations. */ static int update_dirents(char *buf, int nb) { int rv; #define d ((struct direct *)buf) rv = 0; while (nb > 0) { if (inomove[d->d_ino] != d->d_ino) { rv++; d->d_ino = inomove[d->d_ino]; } nb -= d->d_reclen; buf += d->d_reclen; } return (rv); #undef d } /* * Callback function for map_inode_data_blocks, for updating a * directory to point to new inode locations. */ static void update_dir_data(unsigned int bn, unsigned int size, unsigned int nb, int kind) { if (kind == MDB_DATA) { union { struct direct d; char ch[MAXBSIZE]; } buf; readat(fsbtodb(oldsb, bn), &buf, size << oldsb->fs_fshift); if (update_dirents((char *) &buf, nb)) { writeat(fsbtodb(oldsb, bn), &buf, size << oldsb->fs_fshift); } } } static void dirmove_callback(struct dinode * di, unsigned int inum, void *arg) { switch (di->di_mode & IFMT) { case IFDIR: map_inode_data_blocks(di, &update_dir_data); break; } } /* * Update directory entries to point to new inode locations. */ static void update_for_inode_move(void) { map_inodes(&dirmove_callback, newsb->fs_ncg, NULL); } /* * Shrink the filesystem. */ static void shrink(void) { int i; /* Load the inodes off disk - we'll need 'em. */ loadinodes(); /* Update the timestamp. */ newsb->fs_time = timestamp(); /* Update the size figures. */ newsb->fs_size = dbtofsb(newsb, newsize); newsb->fs_ncyl = (newsb->fs_size * NSPF(newsb)) / newsb->fs_spc; newsb->fs_ncg = howmany(newsb->fs_ncyl, newsb->fs_cpg); /* Does the (new) last cg end before the end of its inode area? See * the similar code in grow() for more on this. */ if (cgdmin(newsb, newsb->fs_ncg - 1) > newsb->fs_size) { newsb->fs_ncg--; newsb->fs_ncyl = newsb->fs_ncg * newsb->fs_cpg; newsb->fs_size = (newsb->fs_ncyl * newsb->fs_spc) / NSPF(newsb); printf("Warning: last cylinder group is too small;\n"); printf(" dropping it. New size = %lu.\n", (unsigned long int) fsbtodb(newsb, newsb->fs_size)); } /* Let's make sure we're not being shrunk into oblivion. */ if (newsb->fs_ncg < 1) { printf("Size too small - filesystem would have no cylinders\n"); exit(1); } /* Initialize for block motion. */ blkmove_init(); /* Update csum size, then fix up for the new size */ newsb->fs_cssize = fragroundup(newsb, newsb->fs_ncg * sizeof(struct csum)); csum_fixup(); /* Evict data from any cgs being wholly eliminiated */ for (i = newsb->fs_ncg; i < oldsb->fs_ncg; i++) { int base; int dlow; int dhigh; int dmax; base = cgbase(oldsb, i); dlow = cgsblock(oldsb, i) - base; dhigh = cgdmin(oldsb, i) - base; dmax = oldsb->fs_size - base; if (dmax > cgs[i]->cg_ndblk) dmax = cgs[i]->cg_ndblk; evict_data(cgs[i], 0, dlow); evict_data(cgs[i], dhigh, dmax - dhigh); newsb->fs_cstotal.cs_ndir -= cgs[i]->cg_cs.cs_ndir; newsb->fs_cstotal.cs_nifree -= cgs[i]->cg_cs.cs_nifree; newsb->fs_cstotal.cs_nffree -= cgs[i]->cg_cs.cs_nffree; newsb->fs_cstotal.cs_nbfree -= cgs[i]->cg_cs.cs_nbfree; } /* Update the new last cg. */ cgs[newsb->fs_ncg - 1]->cg_ndblk = newsb->fs_size - ((newsb->fs_ncg - 1) * newsb->fs_fpg); /* Is the new last cg partial? If so, evict any data from the part * being shrunken away. */ if (newsb->fs_size % newsb->fs_fpg) { struct cg *cg; int oldcgsize; int newcgsize; cg = cgs[newsb->fs_ncg - 1]; newcgsize = newsb->fs_size % newsb->fs_fpg; oldcgsize = oldsb->fs_size - ((newsb->fs_ncg - 1) & oldsb->fs_fpg); if (oldcgsize > oldsb->fs_fpg) oldcgsize = oldsb->fs_fpg; evict_data(cg, newcgsize, oldcgsize - newcgsize); clr_bits(cg_blksfree(cg, 0), newcgsize, oldcgsize - newcgsize); } /* Find out whether we would run out of inodes. (Note we haven't * actually done anything to the filesystem yet; all those evict_data * calls just update blkmove.) */ { int slop; slop = 0; for (i = 0; i < newsb->fs_ncg; i++) slop += cgs[i]->cg_cs.cs_nifree; for (; i < oldsb->fs_ncg; i++) slop -= oldsb->fs_ipg - cgs[i]->cg_cs.cs_nifree; if (slop < 0) { printf("Sorry, would run out of inodes\n"); exit(1); } } /* Copy data, then update pointers to data. See the comment header on * perform_data_move for ordering considerations. */ perform_data_move(); update_for_data_move(); /* Now do inodes. Initialize, evict, move, update - see the comment * header on perform_inode_move. */ inomove_init(); for (i = newsb->fs_ncg; i < oldsb->fs_ncg; i++) evict_inodes(cgs[i]); perform_inode_move(); flush_inodes(); update_for_inode_move(); /* Recompute all the bitmaps; most of them probably need it anyway, * the rest are just paranoia and not wanting to have to bother * keeping track of exactly which ones require it. */ for (i = 0; i < newsb->fs_ncg; i++) cgflags[i] |= CGF_DIRTY | CGF_BLKMAPS | CGF_INOMAPS; /* Update the cg_ncyl value for the last cylinder. The condition is * commented out because fsck whines if not - see the similar * condition in grow() for more. */ /* XXX fix once fsck is fixed */ /* if (newsb->fs_ncyl % newsb->fs_cpg) XXX */ /*XXXJTK*/ cgs[newsb->fs_ncg - 1]->cg_ncyl = newsb->fs_ncyl % newsb->fs_cpg; /* Make fs_dsize match the new reality. */ recompute_fs_dsize(); } /* * Recompute the block totals, block cluster summaries, and rotational * position summaries, for a given cg (specified by number), based on * its free-frag bitmap (cg_blksfree()[]). */ static void rescan_blkmaps(int cgn) { struct cg *cg; int f; int b; int blkfree; int blkrun; int fragrun; int fwb; cg = cgs[cgn]; /* Subtract off the current totals from the sb's summary info */ newsb->fs_cstotal.cs_nffree -= cg->cg_cs.cs_nffree; newsb->fs_cstotal.cs_nbfree -= cg->cg_cs.cs_nbfree; /* Clear counters and bitmaps. */ cg->cg_cs.cs_nffree = 0; cg->cg_cs.cs_nbfree = 0; bzero(&cg->cg_frsum[0], MAXFRAG * sizeof(cg->cg_frsum[0])); bzero(&cg_blktot(cg, 0)[0], newsb->fs_cpg * sizeof(cg_blktot(cg, 0)[0])); bzero(&cg_blks(newsb, cg, 0, 0)[0], newsb->fs_cpg * newsb->fs_nrpos * sizeof(cg_blks(newsb, cg, 0, 0)[0])); if (newsb->fs_contigsumsize > 0) { cg->cg_nclusterblks = cg->cg_ndblk / newsb->fs_frag; bzero(&cg_clustersum(cg, 0)[1], newsb->fs_contigsumsize * sizeof(cg_clustersum(cg, 0)[1])); bzero(&cg_clustersfree(cg, 0)[0], howmany((newsb->fs_cpg * newsb->fs_spc) / NSPB(newsb), NBBY)); } /* Scan the free-frag bitmap. Runs of free frags are kept track of * with fragrun, and recorded into cg_frsum[] and cg_cs.cs_nffree; on * each block boundary, entire free blocks are recorded as well. */ blkfree = 1; blkrun = 0; fragrun = 0; f = 0; b = 0; fwb = 0; while (f < cg->cg_ndblk) { if (bit_is_set(cg_blksfree(cg, 0), f)) { fragrun++; } else { blkfree = 0; if (fragrun > 0) { cg->cg_frsum[fragrun]++; cg->cg_cs.cs_nffree += fragrun; } fragrun = 0; } f++; fwb++; if (fwb >= newsb->fs_frag) { if (blkfree) { cg->cg_cs.cs_nbfree++; if (newsb->fs_contigsumsize > 0) set_bits(cg_clustersfree(cg, 0), b, 1); cg_blktot(cg, 0)[cbtocylno(newsb, f - newsb->fs_frag)]++; cg_blks(newsb, cg, cbtocylno(newsb, f - newsb->fs_frag), 0)[cbtorpos(newsb, f - newsb->fs_frag)]++; blkrun++; } else { if (fragrun > 0) { cg->cg_frsum[fragrun]++; cg->cg_cs.cs_nffree += fragrun; } if (newsb->fs_contigsumsize > 0) { if (blkrun > 0) { cg_clustersum(cg, 0)[(blkrun > newsb->fs_contigsumsize) ? newsb->fs_contigsumsize : blkrun]++; } } blkrun = 0; } fwb = 0; b++; blkfree = 1; fragrun = 0; } } if (fragrun > 0) { cg->cg_frsum[fragrun]++; cg->cg_cs.cs_nffree += fragrun; } if ((blkrun > 0) && (newsb->fs_contigsumsize > 0)) { cg_clustersum(cg, 0)[(blkrun > newsb->fs_contigsumsize) ? newsb->fs_contigsumsize : blkrun]++; } /* * Put the updated summary info back into csums, and add it * back into the sb's summary info. Then mark the cg dirty. */ csums[cgn] = cg->cg_cs; newsb->fs_cstotal.cs_nffree += cg->cg_cs.cs_nffree; newsb->fs_cstotal.cs_nbfree += cg->cg_cs.cs_nbfree; cgflags[cgn] |= CGF_DIRTY; } /* * Recompute the cg_inosused()[] bitmap, and the cs_nifree and cs_ndir * values, for a cg, based on the in-core inodes for that cg. */ static void rescan_inomaps(int cgn) { struct cg *cg; int inum; int iwc; cg = cgs[cgn]; newsb->fs_cstotal.cs_ndir -= cg->cg_cs.cs_ndir; newsb->fs_cstotal.cs_nifree -= cg->cg_cs.cs_nifree; cg->cg_cs.cs_ndir = 0; cg->cg_cs.cs_nifree = 0; bzero(&cg_inosused(cg, 0)[0], howmany(newsb->fs_ipg, NBBY)); inum = cgn * newsb->fs_ipg; if (cgn == 0) { set_bits(cg_inosused(cg, 0), 0, 2); iwc = 2; inum += 2; } else { iwc = 0; } for (; iwc < newsb->fs_ipg; iwc++, inum++) { switch (inodes[inum].di_mode & IFMT) { case 0: cg->cg_cs.cs_nifree++; break; case IFDIR: cg->cg_cs.cs_ndir++; /* fall through */ default: set_bits(cg_inosused(cg, 0), iwc, 1); break; } } csums[cgn] = cg->cg_cs; newsb->fs_cstotal.cs_ndir += cg->cg_cs.cs_ndir; newsb->fs_cstotal.cs_nifree += cg->cg_cs.cs_nifree; cgflags[cgn] |= CGF_DIRTY; } /* * Flush cgs to disk, recomputing anything they're marked as needing. */ static void flush_cgs(void) { int i; for (i = 0; i < newsb->fs_ncg; i++) { if (cgflags[i] & CGF_BLKMAPS) { rescan_blkmaps(i); } if (cgflags[i] & CGF_INOMAPS) { rescan_inomaps(i); } if (cgflags[i] & CGF_DIRTY) { cgs[i]->cg_rotor = 0; cgs[i]->cg_frotor = 0; cgs[i]->cg_irotor = 0; writeat(fsbtodb(newsb, cgtod(newsb, i)), cgs[i], cgblksz); } } writeat(fsbtodb(newsb, newsb->fs_csaddr), csums, newsb->fs_cssize); } /* * Write the superblock, both to the main superblock and to each cg's * alternative superblock. */ static void write_sbs(void) { int i; writeat(SBLOCK, newsb, SBSIZE); for (i = 0; i < newsb->fs_ncg; i++) { writeat(fsbtodb(newsb, cgsblock(newsb, i)), newsb, SBSIZE); } } /* * main(). */ int main(int, char **); int main(int ac, char **av) { if (ac != 3) { fprintf(stderr, "Usage: %s filesystem new-size\n", __progname); exit(1); } fd = open(av[1], O_RDWR, 0); if (fd < 0) { fprintf(stderr, "%s: %s: %s\n", __progname, av[1], strerror(errno)); exit(1); } checksmallio(); newsize = atoi(av[2]); oldsb = (struct fs *) & sbbuf; newsb = (struct fs *) (SBSIZE + (char *) &sbbuf); readat(SBLOCK, oldsb, SBSIZE); if (oldsb->fs_magic != FS_MAGIC) { fprintf(stderr, "%s: %s: bad magic number\n", __progname, av[1]); exit(1); } oldsb->fs_qbmask = ~(int64_t) oldsb->fs_bmask; oldsb->fs_qfmask = ~(int64_t) oldsb->fs_fmask; if (oldsb->fs_ipg % INOPB(oldsb)) { printf("ipg[%d] %% INOPB[%d] != 0\n", (int) oldsb->fs_ipg, (int) INOPB(oldsb)); exit(1); } /* The superblock is bigger than struct fs (there are trailing tables, * of non-fixed size); make sure we copy the whole thing. SBSIZE may * be an over-estimate, but we do this just once, so being generous is * cheap. */ bcopy(oldsb, newsb, SBSIZE); loadcgs(); if (newsize > fsbtodb(oldsb, oldsb->fs_size)) { grow(); } else if (newsize < fsbtodb(oldsb, oldsb->fs_size)) { shrink(); } flush_cgs(); write_sbs(); exit(0); }