//
// $Header: D:/ext2-os2/ext2/RCS/ialloc.c,v 1.2 1995/08/08 21:16:44 Willm Exp Willm $
//
// Linux ext2 file system driver for OS/2 2.x and WARP - Allows OS/2 to
// access your Linux ext2fs partitions as normal drive letters.
// OS/2 implementation : Copyright (C) 1995 Matthieu WILLM
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
/*
* linux/fs/ext2/ialloc.c
*
* Copyright (C) 1992, 1993, 1994 Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* BSD ufs-inspired inode and directory allocation by
* Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
*/
/*
* ialloc.c contains the inodes allocation and deallocation routines
*/
/*
* The free inodes are managed by bitmaps. A file system contains several
* blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
* block for inodes, N blocks for the inode table and data blocks.
*
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block. The descriptors are loaded in memory
* when a file system is mounted (see ext2_read_super).
*/
#ifdef OS2
#define INCL_DOSERRORS
#include <os2.h> // From the "Developer Connection Device Driver Kit" version 2.0
#include <fsh.h>
#include <os2/types.h>
#include <os2/os2proto.h>
#include <linux/fs.h>
#include <linux/fs_proto.h>
#include <linux/e2_fs.h>
#include <linux/e2_proto.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <string.h>
#include <linux/locks.h>
#include <asm/bitops.h>
#else
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/locks.h>
#include <asm/bitops.h>
#endif
#ifndef OS2
static struct ext2_group_desc * get_group_desc (struct super_block * sb,
unsigned int block_group,
struct buffer_head ** bh)
#else
static struct ext2_group_desc * get_group_desc (struct super_block * sb,
unsigned long block_group,
struct buffer_head ** bh)
#endif
{
unsigned long group_desc;
unsigned long desc;
struct ext2_group_desc * gdp;
if (block_group >= sb->u.ext2_sb.s_groups_count)
ext2_panic (sb, "get_group_desc",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->u.ext2_sb.s_groups_count);
group_desc = block_group / EXT2_DESC_PER_BLOCK(sb);
desc = block_group % EXT2_DESC_PER_BLOCK(sb);
if (!sb->u.ext2_sb.s_group_desc[group_desc])
ext2_panic (sb, "get_group_desc",
"Group descriptor not loaded - "
"block_group = %d, group_desc = %lu, desc = %lu",
block_group, group_desc, desc);
gdp = (struct ext2_group_desc *)
sb->u.ext2_sb.s_group_desc[group_desc]->b_data;
if (bh)
*bh = sb->u.ext2_sb.s_group_desc[group_desc];
return gdp + desc;
}
#ifndef OS2
static void read_inode_bitmap (struct super_block * sb,
unsigned long block_group,
unsigned int bitmap_nr)
#else
static void read_inode_bitmap (struct super_block * sb,
unsigned long block_group,
unsigned long bitmap_nr)
#endif
{
struct ext2_group_desc * gdp;
struct buffer_head * bh;
gdp = get_group_desc (sb, block_group, NULL);
#ifndef OS2
bh = bread (sb->s_dev, gdp->bg_inode_bitmap, sb->s_blocksize);
#else
bh = bread (sb, gdp->bg_inode_bitmap, sb->s_blocksize);
#endif
if (!bh)
ext2_panic (sb, "read_inode_bitmap",
"Cannot read inode bitmap - "
"block_group = %lu, inode_bitmap = %lu",
block_group, (unsigned long) gdp->bg_inode_bitmap);
sb->u.ext2_sb.s_inode_bitmap_number[bitmap_nr] = block_group;
sb->u.ext2_sb.s_inode_bitmap[bitmap_nr] = bh;
}
/*
* load_inode_bitmap loads the inode bitmap for a blocks group
*
* It maintains a cache for the last bitmaps loaded. This cache is managed
* with a LRU algorithm.
*
* Notes:
* 1/ There is one cache per mounted file system.
* 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups,
* this function reads the bitmap without maintaining a LRU cache.
*/
#ifndef OS2
static int load_inode_bitmap (struct super_block * sb,
unsigned int block_group)
#else
static unsigned long load_inode_bitmap (struct super_block * sb,
unsigned long block_group)
#endif
{
int i, j;
unsigned long inode_bitmap_number;
struct buffer_head * inode_bitmap;
if (block_group >= sb->u.ext2_sb.s_groups_count)
ext2_panic (sb, "load_inode_bitmap",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->u.ext2_sb.s_groups_count);
if (sb->u.ext2_sb.s_loaded_inode_bitmaps > 0 &&
sb->u.ext2_sb.s_inode_bitmap_number[0] == block_group)
return 0;
if (sb->u.ext2_sb.s_groups_count <= EXT2_MAX_GROUP_LOADED) {
if (sb->u.ext2_sb.s_inode_bitmap[block_group]) {
if (sb->u.ext2_sb.s_inode_bitmap_number[block_group] != block_group)
ext2_panic (sb, "load_inode_bitmap",
"block_group != inode_bitmap_number");
else
return block_group;
} else {
read_inode_bitmap (sb, block_group, block_group);
return block_group;
}
}
for (i = 0; i < sb->u.ext2_sb.s_loaded_inode_bitmaps &&
sb->u.ext2_sb.s_inode_bitmap_number[i] != block_group;
i++)
;
if (i < sb->u.ext2_sb.s_loaded_inode_bitmaps &&
sb->u.ext2_sb.s_inode_bitmap_number[i] == block_group) {
inode_bitmap_number = sb->u.ext2_sb.s_inode_bitmap_number[i];
inode_bitmap = sb->u.ext2_sb.s_inode_bitmap[i];
for (j = i; j > 0; j--) {
sb->u.ext2_sb.s_inode_bitmap_number[j] =
sb->u.ext2_sb.s_inode_bitmap_number[j - 1];
sb->u.ext2_sb.s_inode_bitmap[j] =
sb->u.ext2_sb.s_inode_bitmap[j - 1];
}
sb->u.ext2_sb.s_inode_bitmap_number[0] = inode_bitmap_number;
sb->u.ext2_sb.s_inode_bitmap[0] = inode_bitmap;
} else {
if (sb->u.ext2_sb.s_loaded_inode_bitmaps < EXT2_MAX_GROUP_LOADED)
sb->u.ext2_sb.s_loaded_inode_bitmaps++;
else
brelse (sb->u.ext2_sb.s_inode_bitmap[EXT2_MAX_GROUP_LOADED - 1]);
for (j = sb->u.ext2_sb.s_loaded_inode_bitmaps - 1; j > 0; j--) {
sb->u.ext2_sb.s_inode_bitmap_number[j] =
sb->u.ext2_sb.s_inode_bitmap_number[j - 1];
sb->u.ext2_sb.s_inode_bitmap[j] =
sb->u.ext2_sb.s_inode_bitmap[j - 1];
}
read_inode_bitmap (sb, block_group, 0);
}
return 0;
}
/*
* This function sets the deletion time for the inode
*
* This may be used one day by an 'undelete' program
*/
static void set_inode_dtime (struct inode * inode,
struct ext2_group_desc * gdp)
{
unsigned long inode_block;
struct buffer_head * bh;
struct ext2_inode * raw_inode;
inode_block = gdp->bg_inode_table + (((inode->i_ino - 1) %
EXT2_INODES_PER_GROUP(inode->i_sb)) /
EXT2_INODES_PER_BLOCK(inode->i_sb));
#ifndef OS2
bh = bread (inode->i_sb->s_dev, inode_block, inode->i_sb->s_blocksize);
#else
bh = bread (inode->i_sb, inode_block, inode->i_sb->s_blocksize);
#endif
if (!bh)
ext2_panic (inode->i_sb, "set_inode_dtime",
"Cannot load inode table block - "
"inode=%lu, inode_block=%lu",
inode->i_ino, inode_block);
raw_inode = ((struct ext2_inode *) bh->b_data) +
(((inode->i_ino - 1) %
EXT2_INODES_PER_GROUP(inode->i_sb)) %
EXT2_INODES_PER_BLOCK(inode->i_sb));
raw_inode->i_links_count = 0;
raw_inode->i_dtime = CURRENT_TIME;
mark_buffer_dirty(bh, 1);
if (IS_SYNC(inode)) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
brelse (bh);
}
void ext2_free_inode (struct inode * inode)
{
struct super_block * sb;
struct buffer_head * bh;
struct buffer_head * bh2;
unsigned long block_group;
unsigned long bit;
#ifndef OS2
int bitmap_nr;
#else
long bitmap_nr;
#endif
struct ext2_group_desc * gdp;
struct ext2_super_block * es;
if (!inode)
return;
if (!inode->i_dev) {
printk ("ext2_free_inode: inode has no device\n");
return;
}
if (inode->i_count > 1) {
printk ("ext2_free_inode: inode has count=%d\n",
inode->i_count);
return;
}
if (inode->i_nlink) {
printk ("ext2_free_inode: inode has nlink=%d\n",
inode->i_nlink);
return;
}
if (!inode->i_sb) {
printk("ext2_free_inode: inode on nonexistent device\n");
return;
}
ext2_debug ("freeing inode %lu\n", inode->i_ino);
sb = inode->i_sb;
lock_super (sb);
if (inode->i_ino < EXT2_FIRST_INO ||
inode->i_ino > sb->u.ext2_sb.s_es->s_inodes_count) {
ext2_error (sb, "free_inode",
"reserved inode or nonexistent inode");
unlock_super (sb);
return;
}
es = sb->u.ext2_sb.s_es;
block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(sb);
bit = (inode->i_ino - 1) % EXT2_INODES_PER_GROUP(sb);
bitmap_nr = load_inode_bitmap (sb, block_group);
bh = sb->u.ext2_sb.s_inode_bitmap[bitmap_nr];
#ifndef OS2
if (!clear_bit (bit, bh->b_data))
#else
if (!clear_bit (bit, (PINT32)bh->b_data))
#endif
ext2_warning (sb, "ext2_free_inode",
"bit already cleared for inode %lu", inode->i_ino);
else {
gdp = get_group_desc (sb, block_group, &bh2);
gdp->bg_free_inodes_count++;
if (S_ISDIR(inode->i_mode))
gdp->bg_used_dirs_count--;
mark_buffer_dirty(bh2, 1);
es->s_free_inodes_count++;
mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1);
set_inode_dtime (inode, gdp);
}
mark_buffer_dirty(bh, 1);
if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
sb->s_dirt = 1;
clear_inode (inode);
unlock_super (sb);
}
/*
* This function increments the inode version number
*
* This may be used one day by the NFS server
*/
static void inc_inode_version (struct inode * inode,
struct ext2_group_desc *gdp,
int mode)
{
unsigned long inode_block;
struct buffer_head * bh;
struct ext2_inode * raw_inode;
inode_block = gdp->bg_inode_table + (((inode->i_ino - 1) %
EXT2_INODES_PER_GROUP(inode->i_sb)) /
EXT2_INODES_PER_BLOCK(inode->i_sb));
#ifndef OS2
bh = bread (inode->i_sb->s_dev, inode_block, inode->i_sb->s_blocksize);
#else
bh = bread (inode->i_sb, inode_block, inode->i_sb->s_blocksize);
#endif
if (!bh) {
ext2_error (inode->i_sb, "inc_inode_version",
"Cannot load inode table block - "
"inode=%lu, inode_block=%lu\n",
inode->i_ino, inode_block);
inode->u.ext2_i.i_version = 1;
return;
}
raw_inode = ((struct ext2_inode *) bh->b_data) +
(((inode->i_ino - 1) %
EXT2_INODES_PER_GROUP(inode->i_sb)) %
EXT2_INODES_PER_BLOCK(inode->i_sb));
raw_inode->i_version++;
inode->u.ext2_i.i_version = raw_inode->i_version;
mark_buffer_dirty(bh, 1);
brelse (bh);
}
/*
* There are two policies for allocating an inode. If the new inode is
* a directory, then a forward search is made for a block group with both
* free space and a low directory-to-inode ratio; if that fails, then of
* the groups with above-average free space, that group with the fewest
* directories already is chosen.
*
* For other inodes, search forward from the parent directory\'s block
* group to find a free inode.
*/
struct inode * ext2_new_inode (const struct inode * dir, int mode)
{
struct super_block * sb;
struct buffer_head * bh;
struct buffer_head * bh2;
#ifndef OS2
int i, j, avefreei;
#else
ino_t i, j, avefreei;
#endif
struct inode * inode;
#ifndef OS2
int bitmap_nr;
#else
long bitmap_nr;
#endif
struct ext2_group_desc * gdp;
struct ext2_group_desc * tmp;
struct ext2_super_block * es;
if (!dir || !(inode = get_empty_inode ()))
return NULL;
sb = dir->i_sb;
inode->i_sb = sb;
#ifndef OS2
inode->i_flags = sb->s_flags;
#else
inode->i_flags = (unsigned short)sb->s_flags;
#endif
lock_super (sb);
es = sb->u.ext2_sb.s_es;
repeat:
gdp = NULL; i=0;
if (S_ISDIR(mode)) {
avefreei = es->s_free_inodes_count /
sb->u.ext2_sb.s_groups_count;
/* I am not yet convinced that this next bit is necessary.
i = dir->u.ext2_i.i_block_group;
for (j = 0; j < sb->u.ext2_sb.s_groups_count; j++) {
tmp = get_group_desc (sb, i, &bh2);
if ((tmp->bg_used_dirs_count << 8) <
tmp->bg_free_inodes_count) {
gdp = tmp;
break;
}
else
i = ++i % sb->u.ext2_sb.s_groups_count;
}
*/
if (!gdp) {
for (j = 0; j < sb->u.ext2_sb.s_groups_count; j++) {
tmp = get_group_desc (sb, j, &bh2);
if (tmp->bg_free_inodes_count &&
tmp->bg_free_inodes_count >= avefreei) {
if (!gdp ||
(tmp->bg_free_blocks_count >
gdp->bg_free_blocks_count)) {
i = j;
gdp = tmp;
}
}
}
}
}
else
{
/*
* Try to place the inode in its parent directory
*/
i = dir->u.ext2_i.i_block_group;
tmp = get_group_desc (sb, i, &bh2);
if (tmp->bg_free_inodes_count)
gdp = tmp;
else
{
/*
* Use a quadratic hash to find a group with a
* free inode
*/
for (j = 1; j < sb->u.ext2_sb.s_groups_count; j <<= 1) {
i += j;
if (i >= sb->u.ext2_sb.s_groups_count)
i -= sb->u.ext2_sb.s_groups_count;
tmp = get_group_desc (sb, i, &bh2);
if (tmp->bg_free_inodes_count) {
gdp = tmp;
break;
}
}
}
if (!gdp) {
/*
* That failed: try linear search for a free inode
*/
i = dir->u.ext2_i.i_block_group + 1;
for (j = 2; j < sb->u.ext2_sb.s_groups_count; j++) {
if (++i >= sb->u.ext2_sb.s_groups_count)
i = 0;
tmp = get_group_desc (sb, i, &bh2);
if (tmp->bg_free_inodes_count) {
gdp = tmp;
break;
}
}
}
}
if (!gdp) {
unlock_super (sb);
iput(inode);
return NULL;
}
bitmap_nr = load_inode_bitmap (sb, i);
bh = sb->u.ext2_sb.s_inode_bitmap[bitmap_nr];
if ((j = find_first_zero_bit ((unsigned long *) bh->b_data,
EXT2_INODES_PER_GROUP(sb))) <
EXT2_INODES_PER_GROUP(sb)) {
#ifndef OS2
if (set_bit (j, bh->b_data)) {
#else
if (set_bit (j, (long *)bh->b_data)) {
#endif
ext2_warning (sb, "ext2_new_inode",
"bit already set for inode %d", j);
goto repeat;
}
mark_buffer_dirty(bh, 1);
if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
} else {
if (gdp->bg_free_inodes_count != 0) {
ext2_error (sb, "ext2_new_inode",
"Free inodes count corrupted in group %d",
i);
unlock_super (sb);
iput (inode);
return NULL;
}
goto repeat;
}
j += i * EXT2_INODES_PER_GROUP(sb) + 1;
if (j < EXT2_FIRST_INO || j > es->s_inodes_count) {
ext2_error (sb, "ext2_new_inode",
"reserved inode or inode > inodes count - "
"block_group = %d,inode=%d", i, j);
unlock_super (sb);
iput (inode);
return NULL;
}
gdp->bg_free_inodes_count--;
if (S_ISDIR(mode))
gdp->bg_used_dirs_count++;
mark_buffer_dirty(bh2, 1);
es->s_free_inodes_count--;
mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1);
sb->s_dirt = 1;
inode->i_mode = mode;
inode->i_sb = sb;
inode->i_count = 1;
inode->i_nlink = 1;
inode->i_dev = sb->s_dev;
#ifndef OS2
inode->i_uid = current->fsuid;
#else
inode->i_uid = 0;
#endif
if (test_opt (sb, GRPID))
inode->i_gid = dir->i_gid;
else if (dir->i_mode & S_ISGID) {
inode->i_gid = dir->i_gid;
if (S_ISDIR(mode))
mode |= S_ISGID;
} else
#ifndef OS2
inode->i_gid = current->fsgid;
#else
inode->i_gid = 0;
#endif
inode->i_dirt = 1;
inode->i_ino = j;
inode->i_blksize = sb->s_blocksize;
inode->i_blocks = 0;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->u.ext2_i.i_flags = dir->u.ext2_i.i_flags;
if (S_ISLNK(mode))
inode->u.ext2_i.i_flags &= ~(EXT2_IMMUTABLE_FL | EXT2_APPEND_FL);
inode->u.ext2_i.i_faddr = 0;
inode->u.ext2_i.i_frag_no = 0;
inode->u.ext2_i.i_frag_size = 0;
inode->u.ext2_i.i_file_acl = 0;
inode->u.ext2_i.i_dir_acl = 0;
inode->u.ext2_i.i_dtime = 0;
inode->u.ext2_i.i_block_group = i;
inode->i_op = NULL;
if (inode->u.ext2_i.i_flags & EXT2_SYNC_FL)
inode->i_flags |= MS_SYNCHRONOUS;
insert_inode_hash(inode);
inc_inode_version (inode, gdp, mode);
ext2_debug ("allocating inode %lu\n", inode->i_ino);
unlock_super (sb);
return inode;
}
unsigned long ext2_count_free_inodes (struct super_block * sb)
{
#ifdef EXT2FS_DEBUG
struct ext2_super_block * es;
unsigned long desc_count, bitmap_count, x;
int bitmap_nr;
struct ext2_group_desc * gdp;
int i;
lock_super (sb);
es = sb->u.ext2_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
gdp = get_group_desc (sb, i, NULL);
desc_count += gdp->bg_free_inodes_count;
bitmap_nr = load_inode_bitmap (sb, i);
x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr],
EXT2_INODES_PER_GROUP(sb) / 8);
printk ("group %d: stored = %d, counted = %lu\n",
i, gdp->bg_free_inodes_count, x);
bitmap_count += x;
}
printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
es->s_free_inodes_count, desc_count, bitmap_count);
unlock_super (sb);
return desc_count;
#else
return sb->u.ext2_sb.s_es->s_free_inodes_count;
#endif
}
void ext2_check_inodes_bitmap (struct super_block * sb)
{
struct ext2_super_block * es;
unsigned long desc_count, bitmap_count, x;
#ifndef OS2
int bitmap_nr;
#else
unsigned long bitmap_nr;
#endif
struct ext2_group_desc * gdp;
int i;
lock_super (sb);
es = sb->u.ext2_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
gdp = get_group_desc (sb, i, NULL);
desc_count += gdp->bg_free_inodes_count;
bitmap_nr = load_inode_bitmap (sb, i);
x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr],
EXT2_INODES_PER_GROUP(sb) / 8);
if (gdp->bg_free_inodes_count != x)
ext2_error (sb, "ext2_check_inodes_bitmap",
"Wrong free inodes count in group %d, "
"stored = %d, counted = %lu", i,
gdp->bg_free_inodes_count, x);
bitmap_count += x;
}
if (es->s_free_inodes_count != bitmap_count)
ext2_error (sb, "ext2_check_inodes_bitmap",
"Wrong free inodes count in super block, "
"stored = %lu, counted = %lu",
(unsigned long) es->s_free_inodes_count, bitmap_count);
unlock_super (sb);
}
