123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367 |
- /*
- * 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;
- }
- pr_err("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))) {
- pr_err("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)) {
- pr_err("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) {
- pr_warn("unable to locate alternate MDB\n");
- pr_warn("continuing without an alternate MDB\n");
- }
- HFS_SB(sb)->bitmap = kmalloc(8192, GFP_KERNEL);
- 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) {
- pr_err("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) {
- pr_err("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) {
- pr_err("unable to open catalog tree\n");
- goto out;
- }
- attrib = mdb->drAtrb;
- if (!(attrib & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
- pr_warn("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))) {
- pr_warn("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.
- * 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_sync_fs() and flush_mdb().
- * 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 (sb->s_flags & MS_RDONLY)
- return;
- lock_buffer(HFS_SB(sb)->mdb_bh);
- 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);
- lock_buffer(HFS_SB(sb)->alt_mdb_bh);
- 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);
- unlock_buffer(HFS_SB(sb)->alt_mdb_bh);
- 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) {
- pr_err("unable to read volume bitmap\n");
- break;
- }
- len = min((int)sb->s_blocksize - off, size);
- lock_buffer(bh);
- memcpy(bh->b_data + off, ptr, len);
- unlock_buffer(bh);
- mark_buffer_dirty(bh);
- brelse(bh);
- block++;
- off = 0;
- ptr += len;
- size -= len;
- }
- }
- unlock_buffer(HFS_SB(sb)->mdb_bh);
- }
- 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);
- kfree(HFS_SB(sb)->bitmap);
- kfree(HFS_SB(sb));
- sb->s_fs_info = NULL;
- }
|