projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 39d536e6 | 1 | /* ffs_subr.c 4.2 82/10/21 */ |
| 764e2379 BJ |
2 | |
| 3 | #ifdef KERNEL | |
| 4 | #include "../h/param.h" | |
| 5 | #include "../h/fs.h" | |
| 6 | #else | |
| 7 | #include <sys/param.h> | |
| 8 | #include <sys/fs.h> | |
| 9 | #endif | |
| 10 | ||
| 11 | extern int around[9]; | |
| 12 | extern int inside[9]; | |
| 13 | extern u_char *fragtbl[]; | |
| 14 | ||
| 15 | /* | |
| 16 | * Update the frsum fields to reflect addition or deletion | |
| 17 | * of some frags. | |
| 18 | */ | |
| 19 | fragacct(fs, fragmap, fraglist, cnt) | |
| 20 | struct fs *fs; | |
| 21 | int fragmap; | |
| 22 | long fraglist[]; | |
| 23 | int cnt; | |
| 24 | { | |
| 25 | int inblk; | |
| 26 | register int field, subfield; | |
| 27 | register int siz, pos; | |
| 28 | ||
| 29 | inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; | |
| 30 | fragmap <<= 1; | |
| 31 | for (siz = 1; siz < fs->fs_frag; siz++) { | |
| 32 | if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) | |
| 33 | continue; | |
| 34 | field = around[siz]; | |
| 35 | subfield = inside[siz]; | |
| 36 | for (pos = siz; pos <= fs->fs_frag; pos++) { | |
| 37 | if ((fragmap & field) == subfield) { | |
| 38 | fraglist[siz] += cnt; | |
| 39 | pos += siz; | |
| 40 | field <<= siz; | |
| 41 | subfield <<= siz; | |
| 42 | } | |
| 43 | field <<= 1; | |
| 44 | subfield <<= 1; | |
| 45 | } | |
| 46 | } | |
| 47 | } | |
| 48 | ||
| 49 | #ifdef KERNEL | |
| 50 | /* | |
| 51 | * Check that a specified block number is in range. | |
| 52 | */ | |
| 53 | badblock(fs, bn) | |
| 54 | register struct fs *fs; | |
| 55 | daddr_t bn; | |
| 56 | { | |
| 57 | ||
| 58 | if ((unsigned)bn >= fs->fs_size) { | |
| 59 | printf("bad block %d, ", bn); | |
| 60 | fserr(fs, "bad block"); | |
| 61 | return (1); | |
| 62 | } | |
| 63 | return (0); | |
| 64 | } | |
| 65 | #endif | |
| 66 | ||
| 67 | /* | |
| 68 | * block operations | |
| 69 | * | |
| 70 | * check if a block is available | |
| 71 | */ | |
| 72 | isblock(fs, cp, h) | |
| 73 | struct fs *fs; | |
| 74 | unsigned char *cp; | |
| 75 | daddr_t h; | |
| 76 | { | |
| 77 | unsigned char mask; | |
| 78 | ||
| 79 | switch (fs->fs_frag) { | |
| 80 | case 8: | |
| 81 | return (cp[h] == 0xff); | |
| 82 | case 4: | |
| 83 | mask = 0x0f << ((h & 0x1) << 2); | |
| 84 | return ((cp[h >> 1] & mask) == mask); | |
| 85 | case 2: | |
| 86 | mask = 0x03 << ((h & 0x3) << 1); | |
| 87 | return ((cp[h >> 2] & mask) == mask); | |
| 88 | case 1: | |
| 89 | mask = 0x01 << (h & 0x7); | |
| 90 | return ((cp[h >> 3] & mask) == mask); | |
| 91 | default: | |
| 92 | panic("isblock"); | |
| 93 | return (NULL); | |
| 94 | } | |
| 95 | } | |
| 96 | ||
| 97 | /* | |
| 98 | * take a block out of the map | |
| 99 | */ | |
| 100 | clrblock(fs, cp, h) | |
| 101 | struct fs *fs; | |
| 39d536e6 | 102 | u_char *cp; |
| 764e2379 BJ |
103 | daddr_t h; |
| 104 | { | |
| 105 | ||
| 106 | switch ((fs)->fs_frag) { | |
| 107 | case 8: | |
| 108 | cp[h] = 0; | |
| 109 | return; | |
| 110 | case 4: | |
| 111 | cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); | |
| 112 | return; | |
| 113 | case 2: | |
| 114 | cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); | |
| 115 | return; | |
| 116 | case 1: | |
| 117 | cp[h >> 3] &= ~(0x01 << (h & 0x7)); | |
| 118 | return; | |
| 119 | default: | |
| 120 | panic("clrblock"); | |
| 121 | } | |
| 122 | } | |
| 123 | ||
| 124 | /* | |
| 125 | * put a block into the map | |
| 126 | */ | |
| 127 | setblock(fs, cp, h) | |
| 128 | struct fs *fs; | |
| 129 | unsigned char *cp; | |
| 130 | daddr_t h; | |
| 131 | { | |
| 132 | ||
| 133 | switch (fs->fs_frag) { | |
| 134 | ||
| 135 | case 8: | |
| 136 | cp[h] = 0xff; | |
| 137 | return; | |
| 138 | case 4: | |
| 139 | cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); | |
| 140 | return; | |
| 141 | case 2: | |
| 142 | cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); | |
| 143 | return; | |
| 144 | case 1: | |
| 145 | cp[h >> 3] |= (0x01 << (h & 0x7)); | |
| 146 | return; | |
| 147 | default: | |
| 148 | panic("setblock"); | |
| 149 | } | |
| 150 | } |