Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 | /* * linux/fs/hfs/mdb.c * * Copyright (C) 1995-1997 Paul H. Hargrove * (C) 2003 Ardis Technologies <roman@ardistech.com> * This file may be distributed under the terms of the GNU General Public License. * * This file contains functions for reading/writing the MDB. */ #include <linux/cdrom.h> #include <linux/genhd.h> #include <linux/nls.h> #include <linux/slab.h> #include "hfs_fs.h" #include "btree.h" /*================ File-local data types ================*/ /* * The HFS Master Directory Block (MDB). * * Also known as the Volume Information Block (VIB), this structure is * the HFS equivalent of a superblock. * * Reference: _Inside Macintosh: Files_ pages 2-59 through 2-62 * * modified for HFS Extended */ static int hfs_get_last_session(struct super_block *sb, sector_t *start, sector_t *size) { struct cdrom_multisession ms_info; struct cdrom_tocentry te; int res; /* default values */ *start = 0; *size = sb->s_bdev->bd_inode->i_size >> 9; if (HFS_SB(sb)->session >= 0) { te.cdte_track = HFS_SB(sb)->session; te.cdte_format = CDROM_LBA; res = ioctl_by_bdev(sb->s_bdev, CDROMREADTOCENTRY, (unsigned long)&te); if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) { *start = (sector_t)te.cdte_addr.lba << 2; return 0; } printk(KERN_ERR "hfs: invalid session number or type of track\n"); return -EINVAL; } ms_info.addr_format = CDROM_LBA; res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, (unsigned long)&ms_info); if (!res && ms_info.xa_flag) *start = (sector_t)ms_info.addr.lba << 2; return 0; } /* * hfs_mdb_get() * * Build the in-core MDB for a filesystem, including * the B-trees and the volume bitmap. */ int hfs_mdb_get(struct super_block *sb) { struct buffer_head *bh; struct hfs_mdb *mdb, *mdb2; unsigned int block; char *ptr; int off2, len, size, sect; sector_t part_start, part_size; loff_t off; __be16 attrib; /* set the device driver to 512-byte blocks */ size = sb_min_blocksize(sb, HFS_SECTOR_SIZE); if (!size) return -EINVAL; if (hfs_get_last_session(sb, &part_start, &part_size)) return -EINVAL; while (1) { /* See if this is an HFS filesystem */ bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb); if (!bh) goto out; if (mdb->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC)) break; brelse(bh); /* check for a partition block * (should do this only for cdrom/loop though) */ if (hfs_part_find(sb, &part_start, &part_size)) goto out; } HFS_SB(sb)->alloc_blksz = size = be32_to_cpu(mdb->drAlBlkSiz); if (!size || (size & (HFS_SECTOR_SIZE - 1))) { printk(KERN_ERR "hfs: bad allocation block size %d\n", size); goto out_bh; } size = min(HFS_SB(sb)->alloc_blksz, (u32)PAGE_SIZE); /* size must be a multiple of 512 */ while (size & (size - 1)) size -= HFS_SECTOR_SIZE; sect = be16_to_cpu(mdb->drAlBlSt) + part_start; /* align block size to first sector */ while (sect & ((size - 1) >> HFS_SECTOR_SIZE_BITS)) size >>= 1; /* align block size to weird alloc size */ while (HFS_SB(sb)->alloc_blksz & (size - 1)) size >>= 1; brelse(bh); if (!sb_set_blocksize(sb, size)) { printk(KERN_ERR "hfs: unable to set blocksize to %u\n", size); goto out; } bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb); if (!bh) goto out; if (mdb->drSigWord != cpu_to_be16(HFS_SUPER_MAGIC)) goto out_bh; HFS_SB(sb)->mdb_bh = bh; HFS_SB(sb)->mdb = mdb; /* These parameters are read from the MDB, and never written */ HFS_SB(sb)->part_start = part_start; HFS_SB(sb)->fs_ablocks = be16_to_cpu(mdb->drNmAlBlks); HFS_SB(sb)->fs_div = HFS_SB(sb)->alloc_blksz >> sb->s_blocksize_bits; HFS_SB(sb)->clumpablks = be32_to_cpu(mdb->drClpSiz) / HFS_SB(sb)->alloc_blksz; if (!HFS_SB(sb)->clumpablks) HFS_SB(sb)->clumpablks = 1; HFS_SB(sb)->fs_start = (be16_to_cpu(mdb->drAlBlSt) + part_start) >> (sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS); /* These parameters are read from and written to the MDB */ HFS_SB(sb)->free_ablocks = be16_to_cpu(mdb->drFreeBks); HFS_SB(sb)->next_id = be32_to_cpu(mdb->drNxtCNID); HFS_SB(sb)->root_files = be16_to_cpu(mdb->drNmFls); HFS_SB(sb)->root_dirs = be16_to_cpu(mdb->drNmRtDirs); HFS_SB(sb)->file_count = be32_to_cpu(mdb->drFilCnt); HFS_SB(sb)->folder_count = be32_to_cpu(mdb->drDirCnt); /* TRY to get the alternate (backup) MDB. */ sect = part_start + part_size - 2; bh = sb_bread512(sb, sect, mdb2); if (bh) { if (mdb2->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC)) { HFS_SB(sb)->alt_mdb_bh = bh; HFS_SB(sb)->alt_mdb = mdb2; } else brelse(bh); } if (!HFS_SB(sb)->alt_mdb) { printk(KERN_WARNING "hfs: unable to locate alternate MDB\n"); printk(KERN_WARNING "hfs: continuing without an alternate MDB\n"); } HFS_SB(sb)->bitmap = (__be32 *)__get_free_pages(GFP_KERNEL, PAGE_SIZE < 8192 ? 1 : 0); if (!HFS_SB(sb)->bitmap) goto out; /* read in the bitmap */ block = be16_to_cpu(mdb->drVBMSt) + part_start; off = (loff_t)block << HFS_SECTOR_SIZE_BITS; size = (HFS_SB(sb)->fs_ablocks + 8) / 8; ptr = (u8 *)HFS_SB(sb)->bitmap; while (size) { bh = sb_bread(sb, off >> sb->s_blocksize_bits); if (!bh) { printk(KERN_ERR "hfs: unable to read volume bitmap\n"); goto out; } off2 = off & (sb->s_blocksize - 1); len = min((int)sb->s_blocksize - off2, size); memcpy(ptr, bh->b_data + off2, len); brelse(bh); ptr += len; off += len; size -= len; } HFS_SB(sb)->ext_tree = hfs_btree_open(sb, HFS_EXT_CNID, hfs_ext_keycmp); if (!HFS_SB(sb)->ext_tree) { printk(KERN_ERR "hfs: unable to open extent tree\n"); goto out; } HFS_SB(sb)->cat_tree = hfs_btree_open(sb, HFS_CAT_CNID, hfs_cat_keycmp); if (!HFS_SB(sb)->cat_tree) { printk(KERN_ERR "hfs: unable to open catalog tree\n"); goto out; } attrib = mdb->drAtrb; if (!(attrib & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) { printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, " "running fsck.hfs is recommended. mounting read-only.\n"); sb->s_flags |= MS_RDONLY; } if ((attrib & cpu_to_be16(HFS_SB_ATTRIB_SLOCK))) { printk(KERN_WARNING "hfs: filesystem is marked locked, mounting read-only.\n"); sb->s_flags |= MS_RDONLY; } if (!(sb->s_flags & MS_RDONLY)) { /* Mark the volume uncleanly unmounted in case we crash */ attrib &= cpu_to_be16(~HFS_SB_ATTRIB_UNMNT); attrib |= cpu_to_be16(HFS_SB_ATTRIB_INCNSTNT); mdb->drAtrb = attrib; be32_add_cpu(&mdb->drWrCnt, 1); mdb->drLsMod = hfs_mtime(); mark_buffer_dirty(HFS_SB(sb)->mdb_bh); sync_dirty_buffer(HFS_SB(sb)->mdb_bh); } return 0; out_bh: brelse(bh); out: hfs_mdb_put(sb); return -EIO; } /* * hfs_mdb_commit() * * Description: * This updates the MDB on disk (look also at hfs_write_super()). * It does not check, if the superblock has been modified, or * if the filesystem has been mounted read-only. It is mainly * called by hfs_write_super() and hfs_btree_extend(). * Input Variable(s): * struct hfs_mdb *mdb: Pointer to the hfs MDB * int backup; * Output Variable(s): * NONE * Returns: * void * Preconditions: * 'mdb' points to a "valid" (struct hfs_mdb). * Postconditions: * The HFS MDB and on disk will be updated, by copying the possibly * modified fields from the in memory MDB (in native byte order) to * the disk block buffer. * If 'backup' is non-zero then the alternate MDB is also written * and the function doesn't return until it is actually on disk. */ void hfs_mdb_commit(struct super_block *sb) { struct hfs_mdb *mdb = HFS_SB(sb)->mdb; if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) { /* These parameters may have been modified, so write them back */ mdb->drLsMod = hfs_mtime(); mdb->drFreeBks = cpu_to_be16(HFS_SB(sb)->free_ablocks); mdb->drNxtCNID = cpu_to_be32(HFS_SB(sb)->next_id); mdb->drNmFls = cpu_to_be16(HFS_SB(sb)->root_files); mdb->drNmRtDirs = cpu_to_be16(HFS_SB(sb)->root_dirs); mdb->drFilCnt = cpu_to_be32(HFS_SB(sb)->file_count); mdb->drDirCnt = cpu_to_be32(HFS_SB(sb)->folder_count); /* write MDB to disk */ mark_buffer_dirty(HFS_SB(sb)->mdb_bh); } /* write the backup MDB, not returning until it is written. * we only do this when either the catalog or extents overflow * files grow. */ if (test_and_clear_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags) && HFS_SB(sb)->alt_mdb) { hfs_inode_write_fork(HFS_SB(sb)->ext_tree->inode, mdb->drXTExtRec, &mdb->drXTFlSize, NULL); hfs_inode_write_fork(HFS_SB(sb)->cat_tree->inode, mdb->drCTExtRec, &mdb->drCTFlSize, NULL); memcpy(HFS_SB(sb)->alt_mdb, HFS_SB(sb)->mdb, HFS_SECTOR_SIZE); HFS_SB(sb)->alt_mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT); HFS_SB(sb)->alt_mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT); mark_buffer_dirty(HFS_SB(sb)->alt_mdb_bh); sync_dirty_buffer(HFS_SB(sb)->alt_mdb_bh); } if (test_and_clear_bit(HFS_FLG_BITMAP_DIRTY, &HFS_SB(sb)->flags)) { struct buffer_head *bh; sector_t block; char *ptr; int off, size, len; block = be16_to_cpu(HFS_SB(sb)->mdb->drVBMSt) + HFS_SB(sb)->part_start; off = (block << HFS_SECTOR_SIZE_BITS) & (sb->s_blocksize - 1); block >>= sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS; size = (HFS_SB(sb)->fs_ablocks + 7) / 8; ptr = (u8 *)HFS_SB(sb)->bitmap; while (size) { bh = sb_bread(sb, block); if (!bh) { printk(KERN_ERR "hfs: unable to read volume bitmap\n"); break; } len = min((int)sb->s_blocksize - off, size); memcpy(bh->b_data + off, ptr, len); mark_buffer_dirty(bh); brelse(bh); block++; off = 0; ptr += len; size -= len; } } } void hfs_mdb_close(struct super_block *sb) { /* update volume attributes */ if (sb->s_flags & MS_RDONLY) return; HFS_SB(sb)->mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT); HFS_SB(sb)->mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT); mark_buffer_dirty(HFS_SB(sb)->mdb_bh); } /* * hfs_mdb_put() * * Release the resources associated with the in-core MDB. */ void hfs_mdb_put(struct super_block *sb) { if (!HFS_SB(sb)) return; /* free the B-trees */ hfs_btree_close(HFS_SB(sb)->ext_tree); hfs_btree_close(HFS_SB(sb)->cat_tree); /* free the buffers holding the primary and alternate MDBs */ brelse(HFS_SB(sb)->mdb_bh); brelse(HFS_SB(sb)->alt_mdb_bh); unload_nls(HFS_SB(sb)->nls_io); unload_nls(HFS_SB(sb)->nls_disk); free_pages((unsigned long)HFS_SB(sb)->bitmap, PAGE_SIZE < 8192 ? 1 : 0); kfree(HFS_SB(sb)); sb->s_fs_info = NULL; } |