Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/affs/bitmap.c |
| 3 | * |
| 4 | * (c) 1996 Hans-Joachim Widmaier |
| 5 | * |
| 6 | * bitmap.c contains the code that handles all bitmap related stuff - |
| 7 | * block allocation, deallocation, calculation of free space. |
| 8 | */ |
| 9 | |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 10 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include "affs.h" |
| 12 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | u32 |
| 14 | affs_count_free_blocks(struct super_block *sb) |
| 15 | { |
| 16 | struct affs_bm_info *bm; |
| 17 | u32 free; |
| 18 | int i; |
| 19 | |
Fabian Frederick | 9606d9a | 2014-06-06 14:37:25 -0700 | [diff] [blame] | 20 | pr_debug("%s()\n", __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
| 22 | if (sb->s_flags & MS_RDONLY) |
| 23 | return 0; |
| 24 | |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 25 | mutex_lock(&AFFS_SB(sb)->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
| 27 | bm = AFFS_SB(sb)->s_bitmap; |
| 28 | free = 0; |
| 29 | for (i = AFFS_SB(sb)->s_bmap_count; i > 0; bm++, i--) |
| 30 | free += bm->bm_free; |
| 31 | |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 32 | mutex_unlock(&AFFS_SB(sb)->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
| 34 | return free; |
| 35 | } |
| 36 | |
| 37 | void |
| 38 | affs_free_block(struct super_block *sb, u32 block) |
| 39 | { |
| 40 | struct affs_sb_info *sbi = AFFS_SB(sb); |
| 41 | struct affs_bm_info *bm; |
| 42 | struct buffer_head *bh; |
| 43 | u32 blk, bmap, bit, mask, tmp; |
| 44 | __be32 *data; |
| 45 | |
Fabian Frederick | 9606d9a | 2014-06-06 14:37:25 -0700 | [diff] [blame] | 46 | pr_debug("%s(%u)\n", __func__, block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | if (block > sbi->s_partition_size) |
| 49 | goto err_range; |
| 50 | |
| 51 | blk = block - sbi->s_reserved; |
| 52 | bmap = blk / sbi->s_bmap_bits; |
| 53 | bit = blk % sbi->s_bmap_bits; |
| 54 | bm = &sbi->s_bitmap[bmap]; |
| 55 | |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 56 | mutex_lock(&sbi->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
| 58 | bh = sbi->s_bmap_bh; |
| 59 | if (sbi->s_last_bmap != bmap) { |
| 60 | affs_brelse(bh); |
| 61 | bh = affs_bread(sb, bm->bm_key); |
| 62 | if (!bh) |
| 63 | goto err_bh_read; |
| 64 | sbi->s_bmap_bh = bh; |
| 65 | sbi->s_last_bmap = bmap; |
| 66 | } |
| 67 | |
| 68 | mask = 1 << (bit & 31); |
| 69 | data = (__be32 *)bh->b_data + bit / 32 + 1; |
| 70 | |
| 71 | /* mark block free */ |
| 72 | tmp = be32_to_cpu(*data); |
| 73 | if (tmp & mask) |
| 74 | goto err_free; |
| 75 | *data = cpu_to_be32(tmp | mask); |
| 76 | |
| 77 | /* fix checksum */ |
| 78 | tmp = be32_to_cpu(*(__be32 *)bh->b_data); |
| 79 | *(__be32 *)bh->b_data = cpu_to_be32(tmp - mask); |
| 80 | |
| 81 | mark_buffer_dirty(bh); |
Artem Bityutskiy | 3dd8478 | 2012-06-06 18:56:57 +0300 | [diff] [blame] | 82 | affs_mark_sb_dirty(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | bm->bm_free++; |
| 84 | |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 85 | mutex_unlock(&sbi->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | return; |
| 87 | |
| 88 | err_free: |
| 89 | affs_warning(sb,"affs_free_block","Trying to free block %u which is already free", block); |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 90 | mutex_unlock(&sbi->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | return; |
| 92 | |
| 93 | err_bh_read: |
| 94 | affs_error(sb,"affs_free_block","Cannot read bitmap block %u", bm->bm_key); |
| 95 | sbi->s_bmap_bh = NULL; |
| 96 | sbi->s_last_bmap = ~0; |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 97 | mutex_unlock(&sbi->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | return; |
| 99 | |
| 100 | err_range: |
| 101 | affs_error(sb, "affs_free_block","Block %u outside partition", block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | } |
| 103 | |
| 104 | /* |
| 105 | * Allocate a block in the given allocation zone. |
| 106 | * Since we have to byte-swap the bitmap on little-endian |
Daniel Mack | 3ad2f3f | 2010-02-03 08:01:28 +0800 | [diff] [blame] | 107 | * machines, this is rather expensive. Therefore we will |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | * preallocate up to 16 blocks from the same word, if |
| 109 | * possible. We are not doing preallocations in the |
| 110 | * header zone, though. |
| 111 | */ |
| 112 | |
| 113 | u32 |
| 114 | affs_alloc_block(struct inode *inode, u32 goal) |
| 115 | { |
| 116 | struct super_block *sb; |
| 117 | struct affs_sb_info *sbi; |
| 118 | struct affs_bm_info *bm; |
| 119 | struct buffer_head *bh; |
| 120 | __be32 *data, *enddata; |
| 121 | u32 blk, bmap, bit, mask, mask2, tmp; |
| 122 | int i; |
| 123 | |
| 124 | sb = inode->i_sb; |
| 125 | sbi = AFFS_SB(sb); |
| 126 | |
Fabian Frederick | 9606d9a | 2014-06-06 14:37:25 -0700 | [diff] [blame] | 127 | pr_debug("balloc(inode=%lu,goal=%u): ", inode->i_ino, goal); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
| 129 | if (AFFS_I(inode)->i_pa_cnt) { |
| 130 | pr_debug("%d\n", AFFS_I(inode)->i_lastalloc+1); |
| 131 | AFFS_I(inode)->i_pa_cnt--; |
| 132 | return ++AFFS_I(inode)->i_lastalloc; |
| 133 | } |
| 134 | |
| 135 | if (!goal || goal > sbi->s_partition_size) { |
| 136 | if (goal) |
| 137 | affs_warning(sb, "affs_balloc", "invalid goal %d", goal); |
| 138 | //if (!AFFS_I(inode)->i_last_block) |
| 139 | // affs_warning(sb, "affs_balloc", "no last alloc block"); |
| 140 | goal = sbi->s_reserved; |
| 141 | } |
| 142 | |
| 143 | blk = goal - sbi->s_reserved; |
| 144 | bmap = blk / sbi->s_bmap_bits; |
| 145 | bm = &sbi->s_bitmap[bmap]; |
| 146 | |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 147 | mutex_lock(&sbi->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | |
| 149 | if (bm->bm_free) |
| 150 | goto find_bmap_bit; |
| 151 | |
| 152 | find_bmap: |
| 153 | /* search for the next bmap buffer with free bits */ |
| 154 | i = sbi->s_bmap_count; |
| 155 | do { |
| 156 | if (--i < 0) |
| 157 | goto err_full; |
| 158 | bmap++; |
| 159 | bm++; |
| 160 | if (bmap < sbi->s_bmap_count) |
| 161 | continue; |
| 162 | /* restart search at zero */ |
| 163 | bmap = 0; |
| 164 | bm = sbi->s_bitmap; |
| 165 | } while (!bm->bm_free); |
| 166 | blk = bmap * sbi->s_bmap_bits; |
| 167 | |
| 168 | find_bmap_bit: |
| 169 | |
| 170 | bh = sbi->s_bmap_bh; |
| 171 | if (sbi->s_last_bmap != bmap) { |
| 172 | affs_brelse(bh); |
| 173 | bh = affs_bread(sb, bm->bm_key); |
| 174 | if (!bh) |
| 175 | goto err_bh_read; |
| 176 | sbi->s_bmap_bh = bh; |
| 177 | sbi->s_last_bmap = bmap; |
| 178 | } |
| 179 | |
| 180 | /* find an unused block in this bitmap block */ |
| 181 | bit = blk % sbi->s_bmap_bits; |
| 182 | data = (__be32 *)bh->b_data + bit / 32 + 1; |
| 183 | enddata = (__be32 *)((u8 *)bh->b_data + sb->s_blocksize); |
| 184 | mask = ~0UL << (bit & 31); |
| 185 | blk &= ~31UL; |
| 186 | |
| 187 | tmp = be32_to_cpu(*data); |
| 188 | if (tmp & mask) |
| 189 | goto find_bit; |
| 190 | |
| 191 | /* scan the rest of the buffer */ |
| 192 | do { |
| 193 | blk += 32; |
| 194 | if (++data >= enddata) |
| 195 | /* didn't find something, can only happen |
| 196 | * if scan didn't start at 0, try next bmap |
| 197 | */ |
| 198 | goto find_bmap; |
| 199 | } while (!*data); |
| 200 | tmp = be32_to_cpu(*data); |
| 201 | mask = ~0; |
| 202 | |
| 203 | find_bit: |
| 204 | /* finally look for a free bit in the word */ |
| 205 | bit = ffs(tmp & mask) - 1; |
| 206 | blk += bit + sbi->s_reserved; |
| 207 | mask2 = mask = 1 << (bit & 31); |
| 208 | AFFS_I(inode)->i_lastalloc = blk; |
| 209 | |
| 210 | /* prealloc as much as possible within this word */ |
| 211 | while ((mask2 <<= 1)) { |
| 212 | if (!(tmp & mask2)) |
| 213 | break; |
| 214 | AFFS_I(inode)->i_pa_cnt++; |
| 215 | mask |= mask2; |
| 216 | } |
| 217 | bm->bm_free -= AFFS_I(inode)->i_pa_cnt + 1; |
| 218 | |
| 219 | *data = cpu_to_be32(tmp & ~mask); |
| 220 | |
| 221 | /* fix checksum */ |
| 222 | tmp = be32_to_cpu(*(__be32 *)bh->b_data); |
| 223 | *(__be32 *)bh->b_data = cpu_to_be32(tmp + mask); |
| 224 | |
| 225 | mark_buffer_dirty(bh); |
Artem Bityutskiy | 3dd8478 | 2012-06-06 18:56:57 +0300 | [diff] [blame] | 226 | affs_mark_sb_dirty(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 228 | mutex_unlock(&sbi->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | |
| 230 | pr_debug("%d\n", blk); |
| 231 | return blk; |
| 232 | |
| 233 | err_bh_read: |
| 234 | affs_error(sb,"affs_read_block","Cannot read bitmap block %u", bm->bm_key); |
| 235 | sbi->s_bmap_bh = NULL; |
| 236 | sbi->s_last_bmap = ~0; |
| 237 | err_full: |
Matthias Kaehlcke | 7d135a5 | 2008-07-25 19:44:51 -0700 | [diff] [blame] | 238 | mutex_unlock(&sbi->s_bmlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | pr_debug("failed\n"); |
| 240 | return 0; |
| 241 | } |
| 242 | |
| 243 | int affs_init_bitmap(struct super_block *sb, int *flags) |
| 244 | { |
| 245 | struct affs_bm_info *bm; |
| 246 | struct buffer_head *bmap_bh = NULL, *bh = NULL; |
| 247 | __be32 *bmap_blk; |
| 248 | u32 size, blk, end, offset, mask; |
| 249 | int i, res = 0; |
| 250 | struct affs_sb_info *sbi = AFFS_SB(sb); |
| 251 | |
| 252 | if (*flags & MS_RDONLY) |
| 253 | return 0; |
| 254 | |
| 255 | if (!AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag) { |
Fabian Frederick | 0158de1 | 2014-06-06 14:37:24 -0700 | [diff] [blame] | 256 | pr_notice("Bitmap invalid - mounting %s read only\n", sb->s_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | *flags |= MS_RDONLY; |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | sbi->s_last_bmap = ~0; |
| 262 | sbi->s_bmap_bh = NULL; |
| 263 | sbi->s_bmap_bits = sb->s_blocksize * 8 - 32; |
| 264 | sbi->s_bmap_count = (sbi->s_partition_size - sbi->s_reserved + |
| 265 | sbi->s_bmap_bits - 1) / sbi->s_bmap_bits; |
| 266 | size = sbi->s_bmap_count * sizeof(*bm); |
Yan Burman | b593e48 | 2006-12-06 20:40:32 -0800 | [diff] [blame] | 267 | bm = sbi->s_bitmap = kzalloc(size, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | if (!sbi->s_bitmap) { |
Fabian Frederick | 0158de1 | 2014-06-06 14:37:24 -0700 | [diff] [blame] | 269 | pr_err("Bitmap allocation failed\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | return -ENOMEM; |
| 271 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | |
| 273 | bmap_blk = (__be32 *)sbi->s_root_bh->b_data; |
| 274 | blk = sb->s_blocksize / 4 - 49; |
| 275 | end = blk + 25; |
| 276 | |
| 277 | for (i = sbi->s_bmap_count; i > 0; bm++, i--) { |
| 278 | affs_brelse(bh); |
| 279 | |
| 280 | bm->bm_key = be32_to_cpu(bmap_blk[blk]); |
| 281 | bh = affs_bread(sb, bm->bm_key); |
| 282 | if (!bh) { |
Fabian Frederick | 0158de1 | 2014-06-06 14:37:24 -0700 | [diff] [blame] | 283 | pr_err("Cannot read bitmap\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | res = -EIO; |
| 285 | goto out; |
| 286 | } |
| 287 | if (affs_checksum_block(sb, bh)) { |
Fabian Frederick | 0158de1 | 2014-06-06 14:37:24 -0700 | [diff] [blame] | 288 | pr_warn("Bitmap %u invalid - mounting %s read only.\n", |
| 289 | bm->bm_key, sb->s_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | *flags |= MS_RDONLY; |
| 291 | goto out; |
| 292 | } |
Fabian Frederick | 9606d9a | 2014-06-06 14:37:25 -0700 | [diff] [blame] | 293 | pr_debug("read bitmap block %d: %d\n", blk, bm->bm_key); |
Akinobu Mita | 0121ad6 | 2012-07-30 14:41:00 -0700 | [diff] [blame] | 294 | bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | |
| 296 | /* Don't try read the extension if this is the last block, |
| 297 | * but we also need the right bm pointer below |
| 298 | */ |
| 299 | if (++blk < end || i == 1) |
| 300 | continue; |
| 301 | if (bmap_bh) |
| 302 | affs_brelse(bmap_bh); |
| 303 | bmap_bh = affs_bread(sb, be32_to_cpu(bmap_blk[blk])); |
| 304 | if (!bmap_bh) { |
Fabian Frederick | 0158de1 | 2014-06-06 14:37:24 -0700 | [diff] [blame] | 305 | pr_err("Cannot read bitmap extension\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | res = -EIO; |
| 307 | goto out; |
| 308 | } |
| 309 | bmap_blk = (__be32 *)bmap_bh->b_data; |
| 310 | blk = 0; |
| 311 | end = sb->s_blocksize / 4 - 1; |
| 312 | } |
| 313 | |
| 314 | offset = (sbi->s_partition_size - sbi->s_reserved) % sbi->s_bmap_bits; |
| 315 | mask = ~(0xFFFFFFFFU << (offset & 31)); |
| 316 | pr_debug("last word: %d %d %d\n", offset, offset / 32 + 1, mask); |
| 317 | offset = offset / 32 + 1; |
| 318 | |
| 319 | if (mask) { |
| 320 | u32 old, new; |
| 321 | |
| 322 | /* Mark unused bits in the last word as allocated */ |
| 323 | old = be32_to_cpu(((__be32 *)bh->b_data)[offset]); |
| 324 | new = old & mask; |
| 325 | //if (old != new) { |
| 326 | ((__be32 *)bh->b_data)[offset] = cpu_to_be32(new); |
| 327 | /* fix checksum */ |
| 328 | //new -= old; |
| 329 | //old = be32_to_cpu(*(__be32 *)bh->b_data); |
| 330 | //*(__be32 *)bh->b_data = cpu_to_be32(old - new); |
| 331 | //mark_buffer_dirty(bh); |
| 332 | //} |
| 333 | /* correct offset for the bitmap count below */ |
| 334 | //offset++; |
| 335 | } |
| 336 | while (++offset < sb->s_blocksize / 4) |
| 337 | ((__be32 *)bh->b_data)[offset] = 0; |
| 338 | ((__be32 *)bh->b_data)[0] = 0; |
| 339 | ((__be32 *)bh->b_data)[0] = cpu_to_be32(-affs_checksum_block(sb, bh)); |
| 340 | mark_buffer_dirty(bh); |
| 341 | |
| 342 | /* recalculate bitmap count for last block */ |
| 343 | bm--; |
Akinobu Mita | 0121ad6 | 2012-07-30 14:41:00 -0700 | [diff] [blame] | 344 | bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | |
| 346 | out: |
| 347 | affs_brelse(bh); |
| 348 | affs_brelse(bmap_bh); |
| 349 | return res; |
| 350 | } |
| 351 | |
| 352 | void affs_free_bitmap(struct super_block *sb) |
| 353 | { |
| 354 | struct affs_sb_info *sbi = AFFS_SB(sb); |
| 355 | |
| 356 | if (!sbi->s_bitmap) |
| 357 | return; |
| 358 | |
| 359 | affs_brelse(sbi->s_bmap_bh); |
| 360 | sbi->s_bmap_bh = NULL; |
| 361 | sbi->s_last_bmap = ~0; |
| 362 | kfree(sbi->s_bitmap); |
| 363 | sbi->s_bitmap = NULL; |
| 364 | } |