linux/fs/hfs/mdb.c

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/*
* 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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#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;
}