diff options
Diffstat (limited to 'fs/hpfs/alloc.c')
| -rw-r--r-- | fs/hpfs/alloc.c | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/fs/hpfs/alloc.c b/fs/hpfs/alloc.c new file mode 100644 index 000000000000..5503e2c28910 --- /dev/null +++ b/fs/hpfs/alloc.c @@ -0,0 +1,456 @@ +/* + * linux/fs/hpfs/alloc.c + * + * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 + * + * HPFS bitmap operations + */ + +#include "hpfs_fn.h" + +static int hpfs_alloc_if_possible_nolock(struct super_block *s, secno sec); + +/* + * Check if a sector is allocated in bitmap + * This is really slow. Turned on only if chk==2 + */ + +static int chk_if_allocated(struct super_block *s, secno sec, char *msg) +{ + struct quad_buffer_head qbh; + unsigned *bmp; + if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail; + if ((bmp[(sec & 0x3fff) >> 5] >> (sec & 0x1f)) & 1) { + hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec); + goto fail1; + } + hpfs_brelse4(&qbh); + if (sec >= hpfs_sb(s)->sb_dirband_start && sec < hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) { + unsigned ssec = (sec - hpfs_sb(s)->sb_dirband_start) / 4; + if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail; + if ((bmp[ssec >> 5] >> (ssec & 0x1f)) & 1) { + hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec); + goto fail1; + } + hpfs_brelse4(&qbh); + } + return 0; + fail1: + hpfs_brelse4(&qbh); + fail: + return 1; +} + +/* + * Check if sector(s) have proper number and additionally check if they're + * allocated in bitmap. + */ + +int hpfs_chk_sectors(struct super_block *s, secno start, int len, char *msg) +{ + if (start + len < start || start < 0x12 || + start + len > hpfs_sb(s)->sb_fs_size) { + hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start); + return 1; + } + if (hpfs_sb(s)->sb_chk>=2) { + int i; + for (i = 0; i < len; i++) + if (chk_if_allocated(s, start + i, msg)) return 1; + } + return 0; +} + +static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward) +{ + struct quad_buffer_head qbh; + unsigned *bmp; + unsigned bs = near & ~0x3fff; + unsigned nr = (near & 0x3fff) & ~(n - 1); + /*unsigned mnr;*/ + unsigned i, q; + int a, b; + secno ret = 0; + if (n != 1 && n != 4) { + hpfs_error(s, "Bad allocation size: %d", n); + return 0; + } + lock_super(s); + if (bs != ~0x3fff) { + if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls; + } else { + if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls; + } + if (!tstbits(bmp, nr, n + forward)) { + ret = bs + nr; + goto rt; + } + /*if (!tstbits(bmp, nr + n, n + forward)) { + ret = bs + nr + n; + goto rt; + }*/ + q = nr + n; b = 0; + while ((a = tstbits(bmp, q, n + forward)) != 0) { + q += a; + if (n != 1) q = ((q-1)&~(n-1))+n; + if (!b) { + if (q>>5 != nr>>5) { + b = 1; + q = nr & 0x1f; + } + } else if (q > nr) break; + } + if (!a) { + ret = bs + q; + goto rt; + } + nr >>= 5; + /*for (i = nr + 1; i != nr; i++, i &= 0x1ff) {*/ + i = nr; + do { + if (!bmp[i]) goto cont; + if (n + forward >= 0x3f && bmp[i] != -1) goto cont; + q = i<<5; + if (i > 0) { + unsigned k = bmp[i-1]; + while (k & 0x80000000) { + q--; k <<= 1; + } + } + if (n != 1) q = ((q-1)&~(n-1))+n; + while ((a = tstbits(bmp, q, n + forward)) != 0) { + q += a; + if (n != 1) q = ((q-1)&~(n-1))+n; + if (q>>5 > i) break; + } + if (!a) { + ret = bs + q; + goto rt; + } + cont: + i++, i &= 0x1ff; + } while (i != nr); + rt: + if (ret) { + if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (bmp[(ret & 0x3fff) >> 5] | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) { + hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret); + ret = 0; + goto b; + } + bmp[(ret & 0x3fff) >> 5] &= ~(((1 << n) - 1) << (ret & 0x1f)); + hpfs_mark_4buffers_dirty(&qbh); + } + b: + hpfs_brelse4(&qbh); + uls: + unlock_super(s); + return ret; +} + +/* + * Allocation strategy: 1) search place near the sector specified + * 2) search bitmap where free sectors last found + * 3) search all bitmaps + * 4) search all bitmaps ignoring number of pre-allocated + * sectors + */ + +secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward, int lock) +{ + secno sec; + int i; + unsigned n_bmps; + struct hpfs_sb_info *sbi = hpfs_sb(s); + int f_p = 0; + int near_bmp; + if (forward < 0) { + forward = -forward; + f_p = 1; + } + if (lock) hpfs_lock_creation(s); + n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14; + if (near && near < sbi->sb_fs_size) { + if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret; + near_bmp = near >> 14; + } else near_bmp = n_bmps / 2; + /* + if (b != -1) { + if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) { + b &= 0x0fffffff; + goto ret; + } + if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret; + */ + if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc; + less_fwd: + for (i = 0; i < n_bmps; i++) { + if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) { + sbi->sb_c_bitmap = near_bmp+i; + goto ret; + } + if (!forward) { + if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) { + sbi->sb_c_bitmap = near_bmp-i-1; + goto ret; + } + } else { + if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) { + sbi->sb_c_bitmap = near_bmp+i-n_bmps; + goto ret; + } + } + if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) { + goto ret; + } + } + if (!f_p) { + if (forward) { + sbi->sb_max_fwd_alloc = forward * 3 / 4; + forward /= 2; + goto less_fwd; + } + } + sec = 0; + ret: + if (sec && f_p) { + for (i = 0; i < forward; i++) { + if (!hpfs_alloc_if_possible_nolock(s, sec + i + 1)) { + hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i); + sec = 0; + break; + } + } + } + if (lock) hpfs_unlock_creation(s); + return sec; +} + +static secno alloc_in_dirband(struct super_block *s, secno near, int lock) +{ + unsigned nr = near; + secno sec; + struct hpfs_sb_info *sbi = hpfs_sb(s); + if (nr < sbi->sb_dirband_start) + nr = sbi->sb_dirband_start; + if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size) + nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4; + nr -= sbi->sb_dirband_start; + nr >>= 2; + if (lock) hpfs_lock_creation(s); + sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0); + if (lock) hpfs_unlock_creation(s); + if (!sec) return 0; + return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start; +} + +/* Alloc sector if it's free */ + +static int hpfs_alloc_if_possible_nolock(struct super_block *s, secno sec) +{ + struct quad_buffer_head qbh; + unsigned *bmp; + lock_super(s); + if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end; + if (bmp[(sec & 0x3fff) >> 5] & (1 << (sec & 0x1f))) { + bmp[(sec & 0x3fff) >> 5] &= ~(1 << (sec & 0x1f)); + hpfs_mark_4buffers_dirty(&qbh); + hpfs_brelse4(&qbh); + unlock_super(s); + return 1; + } + hpfs_brelse4(&qbh); + end: + unlock_super(s); + return 0; +} + +int hpfs_alloc_if_possible(struct super_block *s, secno sec) +{ + int r; + hpfs_lock_creation(s); + r = hpfs_alloc_if_possible_nolock(s, sec); + hpfs_unlock_creation(s); + return r; +} + +/* Free sectors in bitmaps */ + +void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n) +{ + struct quad_buffer_head qbh; + unsigned *bmp; + struct hpfs_sb_info *sbi = hpfs_sb(s); + /*printk("2 - ");*/ + if (!n) return; + if (sec < 0x12) { + hpfs_error(s, "Trying to free reserved sector %08x", sec); + return; + } + lock_super(s); + sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n; + if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff; + new_map: + if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) { + unlock_super(s); + return; + } + new_tst: + if ((bmp[(sec & 0x3fff) >> 5] >> (sec & 0x1f) & 1)) { + hpfs_error(s, "sector %08x not allocated", sec); + hpfs_brelse4(&qbh); + unlock_super(s); + return; + } + bmp[(sec & 0x3fff) >> 5] |= 1 << (sec & 0x1f); + if (!--n) { + hpfs_mark_4buffers_dirty(&qbh); + hpfs_brelse4(&qbh); + unlock_super(s); + return; + } + if (!(++sec & 0x3fff)) { + hpfs_mark_4buffers_dirty(&qbh); + hpfs_brelse4(&qbh); + goto new_map; + } + goto new_tst; +} + +/* + * Check if there are at least n free dnodes on the filesystem. + * Called before adding to dnode. If we run out of space while + * splitting dnodes, it would corrupt dnode tree. + */ + +int hpfs_check_free_dnodes(struct super_block *s, int n) +{ + int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14; + int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff; + int i, j; + unsigned *bmp; + struct quad_buffer_head qbh; + if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) { + for (j = 0; j < 512; j++) { + unsigned k; + if (!bmp[j]) continue; + for (k = bmp[j]; k; k >>= 1) if (k & 1) if (!--n) { + hpfs_brelse4(&qbh); + return 0; + } + } + } + hpfs_brelse4(&qbh); + i = 0; + if (hpfs_sb(s)->sb_c_bitmap != -1) { + bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1"); + goto chk_bmp; + } + chk_next: + if (i == b) i++; + if (i >= n_bmps) return 1; + bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2"); + chk_bmp: + if (bmp) { + for (j = 0; j < 512; j++) { + unsigned k; + if (!bmp[j]) continue; + for (k = 0xf; k; k <<= 4) + if ((bmp[j] & k) == k) { + if (!--n) { + hpfs_brelse4(&qbh); + return 0; + } + } + } + hpfs_brelse4(&qbh); + } + i++; + goto chk_next; +} + +void hpfs_free_dnode(struct super_block *s, dnode_secno dno) +{ + if (hpfs_sb(s)->sb_chk) if (dno & 3) { + hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno); + return; + } + if (dno < hpfs_sb(s)->sb_dirband_start || + dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) { + hpfs_free_sectors(s, dno, 4); + } else { + struct quad_buffer_head qbh; + unsigned *bmp; + unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4; + lock_super(s); + if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) { + unlock_super(s); + return; + } + bmp[ssec >> 5] |= 1 << (ssec & 0x1f); + hpfs_mark_4buffers_dirty(&qbh); + hpfs_brelse4(&qbh); + unlock_super(s); + } +} + +struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near, + dnode_secno *dno, struct quad_buffer_head *qbh, + int lock) +{ + struct dnode *d; + if (hpfs_count_one_bitmap(s, hpfs_sb(s)->sb_dmap) > FREE_DNODES_ADD) { + if (!(*dno = alloc_in_dirband(s, near, lock))) + if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock))) return NULL; + } else { + if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock))) + if (!(*dno = alloc_in_dirband(s, near, lock))) return NULL; + } + if (!(d = hpfs_get_4sectors(s, *dno, qbh))) { + hpfs_free_dnode(s, *dno); + return NULL; + } + memset(d, 0, 2048); + d->magic = DNODE_MAGIC; + d->first_free = 52; + d->dirent[0] = 32; + d->dirent[2] = 8; + d->dirent[30] = 1; + d->dirent[31] = 255; + d->self = *dno; + return d; +} + +struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno, + struct buffer_head **bh) +{ + struct fnode *f; + if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD, 1))) return NULL; + if (!(f = hpfs_get_sector(s, *fno, bh))) { + hpfs_free_sectors(s, *fno, 1); + return NULL; + } + memset(f, 0, 512); + f->magic = FNODE_MAGIC; + f->ea_offs = 0xc4; + f->btree.n_free_nodes = 8; + f->btree.first_free = 8; + return f; +} + +struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano, + struct buffer_head **bh) +{ + struct anode *a; + if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD, 1))) return NULL; + if (!(a = hpfs_get_sector(s, *ano, bh))) { + hpfs_free_sectors(s, *ano, 1); + return NULL; + } + memset(a, 0, 512); + a->magic = ANODE_MAGIC; + a->self = *ano; + a->btree.n_free_nodes = 40; + a->btree.n_used_nodes = 0; + a->btree.first_free = 8; + return a; +} |