//
// $Header: D:/ext2-os2/ext2/RCS/inode.c,v 1.13 1995/08/16 17:34:31 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.



#ifdef OS2
#define INCL_DOSERRORS
#include <os2.h>		// From the "Developer Connection Device Driver Kit" version 2.0
#endif

#include <fsh.h>
#include <os2/types.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/sched.h>

#include <os2/errors.h>

#include <os2/log.h>
#include <os2/os2proto.h>
#include <linux/fs.h>
#include <linux/e2_fs.h>
#include <linux/fs_proto.h>
#include <linux/e2_proto.h>
#include <linux/locks.h>


extern unsigned long event;




void ext2_put_inode (struct inode * inode)
{
#ifdef OS2
#ifdef FS_TRACE
	kernel_printf("ext2_put_inode - inode = %lu, i_nlink = %d", inode->i_ino, inode->i_nlink);
#endif
#endif
	ext2_discard_prealloc (inode);
	if (inode->i_nlink || inode->i_ino == EXT2_ACL_IDX_INO ||
	    inode->i_ino == EXT2_ACL_DATA_INO)
		return;
	inode->i_size = 0;
	if (inode->i_blocks)
		ext2_truncate (inode);
	ext2_free_inode (inode);
}

/**********************************************************************************/
/*** From /usr/src/linux/linux-1.2.1/fs/ext2/inode.c inode_bmap()               ***/
/**********************************************************************************/
#define inode_bmap(inode, nr) ((inode)->u.ext2_i.i_data[(nr)])
/**********************************************************************************/


/**********************************************************************************/
/*** From /usr/src/linux/linux-1.2.1/fs/ext2/inode.c block_bmap()               ***/
/**********************************************************************************/
static blk_t block_bmap (struct buffer_head * bh, blk_t nr)
{
	blk_t tmp;

	if (!bh)
		return 0;
	tmp = ((pblk_t) bh->b_data)[nr];
	brelse (bh);
	return tmp;
}
/**********************************************************************************/

void ext2_discard_prealloc (struct inode *inode)
{
#ifdef EXT2_PREALLOCATE
	if (inode->u.ext2_i.i_prealloc_count) {
#ifndef OS2
		int i = inode->u.ext2_i.i_prealloc_count;
#else
		long i = inode->u.ext2_i.i_prealloc_count;
#endif
		inode->u.ext2_i.i_prealloc_count = 0;
		ext2_free_blocks (inode->i_sb,
				  inode->u.ext2_i.i_prealloc_block,
				  i);
	}
#endif
}



#ifndef OS2
struct buffer_head * ext2_bread (struct inode * inode, int block, 
				 int create, int *err)
{
	struct buffer_head * bh;
#else
struct buffer_head * ext2_bread (struct inode * inode, blk_t block, 
				 blk_t create, int *err)
{
	struct buffer_head * bh;
#endif
	bh = ext2_getblk (inode, block, create, err);
	if (!bh || bh->b_uptodate)
		return bh;
	ll_rw_block (READ, 1, &bh);
	wait_on_buffer (bh);
	if (bh->b_uptodate)
		return bh;
	brelse (bh);
	*err = -EIO;
	return NULL;

}

void ext2_read_inode (struct inode * inode)
{
	struct buffer_head * bh;
	struct ext2_inode * raw_inode;
	unsigned long block_group;
	unsigned long group_desc;
	unsigned long desc;
	unsigned long block;
	struct ext2_group_desc * gdp;

#ifdef FS_TRACE
        kernel_printf("ext2_read_inode( %lu )", inode->i_ino);
#endif

	if ((inode->i_ino != EXT2_ROOT_INO && inode->i_ino != EXT2_ACL_IDX_INO &&
	     inode->i_ino != EXT2_ACL_DATA_INO && inode->i_ino < EXT2_FIRST_INO) ||
	    inode->i_ino > inode->i_sb->u.ext2_sb.s_es->s_inodes_count) {
		ext2_error (inode->i_sb, "ext2_read_inode",
			    "bad inode number: %lu", inode->i_ino);
		return;
	}
	block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
	if (block_group >= inode->i_sb->u.ext2_sb.s_groups_count)
		ext2_panic (inode->i_sb, "ext2_read_inode",
			    "group >= groups count");
	group_desc = block_group / EXT2_DESC_PER_BLOCK(inode->i_sb);
	desc = block_group % EXT2_DESC_PER_BLOCK(inode->i_sb);
	bh = inode->i_sb->u.ext2_sb.s_group_desc[group_desc];
	if (!bh)
		ext2_panic (inode->i_sb, "ext2_read_inode",
			    "Descriptor not loaded");
	gdp = (struct ext2_group_desc *) bh->b_data;
	block = gdp[desc].bg_inode_table +
		(((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb))
		 / EXT2_INODES_PER_BLOCK(inode->i_sb));
#ifndef OS2
	if (!(bh = bread (inode->i_dev, block, inode->i_sb->s_blocksize)))
#else
	if (!(bh = bread (inode->i_sb, block, inode->i_sb->s_blocksize)))
#endif
		ext2_panic (inode->i_sb, "ext2_read_inode",
			    "unable to read i-node block - "
			    "inode=%lu, block=%lu", inode->i_ino, block);
	raw_inode = ((struct ext2_inode *) bh->b_data) +
		(inode->i_ino - 1) % EXT2_INODES_PER_BLOCK(inode->i_sb);
	inode->i_mode = raw_inode->i_mode;
	inode->i_uid = raw_inode->i_uid;
	inode->i_gid = raw_inode->i_gid;
	inode->i_nlink = raw_inode->i_links_count;
	inode->i_size = raw_inode->i_size;
	inode->i_atime = raw_inode->i_atime;
	inode->i_ctime = raw_inode->i_ctime;
	inode->i_mtime = raw_inode->i_mtime;
	inode->u.ext2_i.i_dtime = raw_inode->i_dtime;
	inode->i_blksize = inode->i_sb->s_blocksize;
	inode->i_blocks = raw_inode->i_blocks;
	inode->i_version = ++event;
	inode->u.ext2_i.i_flags = raw_inode->i_flags;
	inode->u.ext2_i.i_faddr = raw_inode->i_faddr;
	inode->u.ext2_i.i_frag_no = raw_inode->i_frag;
	inode->u.ext2_i.i_frag_size = raw_inode->i_fsize;
	inode->u.ext2_i.i_osync = 0;
	inode->u.ext2_i.i_file_acl = raw_inode->i_file_acl;
	inode->u.ext2_i.i_dir_acl = raw_inode->i_dir_acl;
	inode->u.ext2_i.i_version = raw_inode->i_version;
	inode->u.ext2_i.i_block_group = block_group;
	inode->u.ext2_i.i_next_alloc_block = 0;
	inode->u.ext2_i.i_next_alloc_goal = 0;
	if (inode->u.ext2_i.i_prealloc_count)
		ext2_error (inode->i_sb, "ext2_read_inode",
			    "New inode has non-zero prealloc count!");
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		inode->i_rdev = raw_inode->i_block[0];
	else for (block = 0; block < EXT2_N_BLOCKS; block++)
		inode->u.ext2_i.i_data[block] = raw_inode->i_block[block];
	brelse (bh);
	inode->i_op = NULL;
	if (inode->i_ino == EXT2_ACL_IDX_INO ||
	    inode->i_ino == EXT2_ACL_DATA_INO)
		/* Nothing to do */ ;
	else if (S_ISREG(inode->i_mode))
		inode->i_op = &ext2_file_inode_operations;
	else if (S_ISDIR(inode->i_mode))
		inode->i_op = &ext2_dir_inode_operations;
#ifndef OS2
	else if (S_ISLNK(inode->i_mode))
		inode->i_op = &ext2_symlink_inode_operations;
	else if (S_ISCHR(inode->i_mode))
		inode->i_op = &chrdev_inode_operations;
	else if (S_ISBLK(inode->i_mode))
		inode->i_op = &blkdev_inode_operations;
	else if (S_ISFIFO(inode->i_mode))
		init_fifo(inode);
#endif
	if (inode->u.ext2_i.i_flags & EXT2_SYNC_FL)
		inode->i_flags |= MS_SYNCHRONOUS;
	if (inode->u.ext2_i.i_flags & EXT2_APPEND_FL)
		inode->i_flags |= S_APPEND;
	if (inode->u.ext2_i.i_flags & EXT2_IMMUTABLE_FL)
		inode->i_flags |= S_IMMUTABLE;
}


#ifdef OS2
static blk_t ext2_alloc_block (struct inode * inode, unsigned long goal)
#else
static int ext2_alloc_block (struct inode * inode, unsigned long goal)
#endif
{
#ifdef EXT2FS_DEBUG 
	static unsigned long alloc_hits = 0, alloc_attempts = 0;
#endif
	unsigned long result;
	struct buffer_head * bh;


	wait_on_super (inode->i_sb);


#ifdef EXT2_PREALLOCATE
	if (inode->u.ext2_i.i_prealloc_count &&
	    (goal == inode->u.ext2_i.i_prealloc_block ||
	     goal + 1 == inode->u.ext2_i.i_prealloc_block))
	{		
		result = inode->u.ext2_i.i_prealloc_block++;
		inode->u.ext2_i.i_prealloc_count--;
#ifdef EXT2FS_DEBUG
		ext2_debug ("preallocation hit (%lu/%lu).\n",
			    ++alloc_hits, ++alloc_attempts);
#endif
		/* It doesn't matter if we block in getblk() since
		   we have already atomically allocated the block, and
		   are only clearing it now. */
		if (!(bh = getblk (inode->i_sb->s_dev, result,
				   inode->i_sb->s_blocksize))) {

			ext2_error (inode->i_sb, "ext2_alloc_block",
				    "cannot get block %lu", result);
			return 0;
		}
		memset(bh->b_data, 0, inode->i_sb->s_blocksize);
		bh->b_uptodate = 1;
		mark_buffer_dirty(bh, 1);
		brelse (bh);
	} else {
		ext2_discard_prealloc (inode);
#ifdef EXT2FS_DEBUG
		ext2_debug ("preallocation miss (%lu/%lu).\n",
			    alloc_hits, ++alloc_attempts);
#endif
		if (S_ISREG(inode->i_mode))
			result = ext2_new_block
				(inode->i_sb, goal,
				 &inode->u.ext2_i.i_prealloc_count,
				 &inode->u.ext2_i.i_prealloc_block);
		else
			result = ext2_new_block (inode->i_sb, goal, 0, 0);
	}
#else
	result = ext2_new_block (inode->i_sb, goal, 0, 0);
#endif
	return result;
}






#ifdef OS2
static struct buffer_head * inode_getblk (struct inode * inode, blk_t nr,
					  blk_t create, blk_t new_block, int *err)
#else
static struct buffer_head * inode_getblk (struct inode * inode, int nr,
					  int create, int new_block, int * err)
#endif
{
#ifdef OS2
	u32 *p;
	blk_t tmp, goal = 0;
	struct buffer_head * result;
	blk_t blocks = inode->i_sb->s_blocksize / 512;
#else
	u32 * p;
	int tmp, goal = 0;
	struct buffer_head * result;
	int blocks = inode->i_sb->s_blocksize / 512;
#endif

	p = inode->u.ext2_i.i_data + nr;
repeat:
	tmp = *p;
	if (tmp) {
		result = getblk (inode->i_dev, tmp, inode->i_sb->s_blocksize);
		if (tmp == *p)
			return result;
		brelse (result);
		goto repeat;
	}
	if (!create || new_block >= 
	    (current->rlim[RLIMIT_FSIZE].rlim_cur >>
	     EXT2_BLOCK_SIZE_BITS(inode->i_sb))) {
		*err = -EFBIG;
		return NULL;
	}
	if (inode->u.ext2_i.i_next_alloc_block == new_block)
		goal = inode->u.ext2_i.i_next_alloc_goal;

#ifndef OS2
	ext2_debug ("hint = %d,", goal);
#endif
	if (!goal) {
		for (tmp = nr - 1; tmp >= 0; tmp--) {
			if (inode->u.ext2_i.i_data[tmp]) {
				goal = inode->u.ext2_i.i_data[tmp];
				break;
			}
		}
		if (!goal)
			goal = (inode->u.ext2_i.i_block_group * 
				EXT2_BLOCKS_PER_GROUP(inode->i_sb)) +
			       inode->i_sb->u.ext2_sb.s_es->s_first_data_block;
	}

#ifndef OS2
	ext2_debug ("goal = %d.\n", goal);
#endif
	tmp = ext2_alloc_block (inode, goal);
	if (!tmp)
		return NULL;
	result = getblk (inode->i_dev, tmp, inode->i_sb->s_blocksize);
	if (*p) {
		ext2_free_blocks (inode->i_sb, tmp, 1);
		brelse (result);
		goto repeat;
	}
	*p = tmp;
	inode->u.ext2_i.i_next_alloc_block = new_block;
	inode->u.ext2_i.i_next_alloc_goal = tmp;
	inode->i_ctime = CURRENT_TIME;
	inode->i_blocks += blocks;

	if (IS_SYNC(inode) || inode->u.ext2_i.i_osync)
		ext2_sync_inode (inode);
	else
		inode->i_dirt = 1;
	return result;
}

#ifdef OS2
static struct buffer_head * block_getblk (struct inode * inode,
					  struct buffer_head * bh, blk_t nr,
					  blk_t create, blk_t blocksize,
					  blk_t new_block, int *err)
#else
static struct buffer_head * block_getblk (struct inode * inode,
					  struct buffer_head * bh, int nr,
					  int create, int blocksize, 
					  int new_block, int * err)
#endif
{
#ifndef OS2
	int tmp, goal = 0;
	u32 * p;
	struct buffer_head * result;
	int blocks = inode->i_sb->s_blocksize / 512;
#else
	blk_t tmp, goal = 0;
	u32 *p;
	struct buffer_head * result;
	blk_t blocks = inode->i_sb->s_blocksize / 512;
#endif
#ifndef OS2
	if (!bh)
		return NULL;
#else
	if (!bh) {
		return NULL;
                kernel_printf("WARNING - block_getblk called with a NULL buffer");
        }
#endif

	if (!bh->b_uptodate) {
		ll_rw_block (READ, 1, &bh);
		wait_on_buffer (bh);
		if (!bh->b_uptodate) {
			brelse (bh);
			return NULL;
		}
	}


	p = (u32 *) bh->b_data + nr;
repeat:
	tmp = *p;
	if (tmp) {
		result = getblk (bh->b_dev, tmp, blocksize);
		if (tmp == *p) {
			brelse (bh);
			return result;
		}
		brelse (result);
		goto repeat;
	}
	if (!create || new_block >= 
	    (current->rlim[RLIMIT_FSIZE].rlim_cur >> 
	     EXT2_BLOCK_SIZE_BITS(inode->i_sb))) {
		brelse (bh);
		*err = -EFBIG;
		return NULL;
	}
	if (inode->u.ext2_i.i_next_alloc_block == new_block)
		goal = inode->u.ext2_i.i_next_alloc_goal;
	if (!goal) {
		for (tmp = nr - 1; tmp >= 0; tmp--) {
			if (((u32 *) bh->b_data)[tmp]) {
				goal = ((u32 *)bh->b_data)[tmp];
				break;
			}
		}
		if (!goal)
			goal = bh->b_blocknr;
	}
	tmp = ext2_alloc_block (inode, goal);
	if (!tmp) {
		brelse (bh);
		return NULL;
	}
	result = getblk (bh->b_dev, tmp, blocksize);
	if (*p) {
		ext2_free_blocks (inode->i_sb, tmp, 1);
		brelse (result);
		goto repeat;
	}
	*p = tmp;
	mark_buffer_dirty(bh, 1);

	if (IS_SYNC(inode) || inode->u.ext2_i.i_osync) {
		ll_rw_block (WRITE, 1, &bh);
		wait_on_buffer (bh);
	}

	inode->i_ctime = CURRENT_TIME;
	inode->i_blocks += blocks;
	inode->i_dirt = 1;
	inode->u.ext2_i.i_next_alloc_block = new_block;
	inode->u.ext2_i.i_next_alloc_goal = tmp;
	brelse (bh);
	return result;
}




#ifndef OS2
struct buffer_head * ext2_getblk (struct inode * inode, long block,
				  int create, int * err)
#else
struct buffer_head * ext2_getblk (struct inode * inode, blk_t block,
				  blk_t create, int *err)
#endif
{
	struct buffer_head * bh;
	unsigned long b;
	unsigned long addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);

#ifdef OS2
	//
	// This is for OS/2 OPEN_FLAGS_DASD support (direct access to the whole device)
	// 
	if(inode->i_ino == INODE_DASD) {
		return bread(inode->i_sb, block, inode->i_sb->s_blocksize);
        }
#endif

	*err = -EIO;
	if (block < 0) {
		ext2_warning (inode->i_sb, "ext2_getblk", "block < 0");
		return NULL;
	}
	if (block > EXT2_NDIR_BLOCKS + addr_per_block  +
		    addr_per_block * addr_per_block +
		    addr_per_block * addr_per_block * addr_per_block) {
		ext2_warning (inode->i_sb, "ext2_getblk", "block > big");
                return NULL;
	}
	/*
	 * If this is a sequential block allocation, set the next_alloc_block
	 * to this block now so that all the indblock and data block
	 * allocations use the same goal zone
	 */
#ifndef OS2
	ext2_debug ("block %lu, next %lu, goal %lu.\n", block, 
		    inode->u.ext2_i.i_next_alloc_block,
		    inode->u.ext2_i.i_next_alloc_goal);
#endif
	if (block == inode->u.ext2_i.i_next_alloc_block + 1) {
		inode->u.ext2_i.i_next_alloc_block++;
		inode->u.ext2_i.i_next_alloc_goal++;
	}

	*err = -ENOSPC;
	b = block;
	if (block < EXT2_NDIR_BLOCKS)
		return inode_getblk (inode, block, create, b, err);
	block -= EXT2_NDIR_BLOCKS;
	if (block < addr_per_block) {
		bh = inode_getblk (inode, EXT2_IND_BLOCK, create, b, err);
		return block_getblk (inode, bh, block, create,
				     inode->i_sb->s_blocksize, b, err);
	}
	block -= addr_per_block;
	if (block < addr_per_block * addr_per_block) {
		bh = inode_getblk (inode, EXT2_DIND_BLOCK, create, b, err);
		bh = block_getblk (inode, bh, block / addr_per_block, create,
				   inode->i_sb->s_blocksize, b, err);
		return block_getblk (inode, bh, block & (addr_per_block - 1),
				     create, inode->i_sb->s_blocksize, b, err);
	}
	block -= addr_per_block * addr_per_block;
	bh = inode_getblk (inode, EXT2_TIND_BLOCK, create, b, err);
	bh = block_getblk (inode, bh, block/(addr_per_block * addr_per_block),
			   create, inode->i_sb->s_blocksize, b, err);
	bh = block_getblk (inode, bh, (block/addr_per_block) & (addr_per_block - 1),
			   create, inode->i_sb->s_blocksize, b, err);
	return block_getblk (inode, bh, block & (addr_per_block - 1), create,
			     inode->i_sb->s_blocksize, b, err);
}


static struct buffer_head * ext2_update_inode (struct inode * inode)
{
	struct buffer_head * bh;
	struct ext2_inode * raw_inode;
	unsigned long block_group;
	unsigned long group_desc;
	unsigned long desc;
	unsigned long block;
	struct ext2_group_desc * gdp;

	if ((inode->i_ino != EXT2_ROOT_INO && inode->i_ino < EXT2_FIRST_INO) ||
	    inode->i_ino > inode->i_sb->u.ext2_sb.s_es->s_inodes_count) {
		ext2_error (inode->i_sb, "ext2_write_inode",
			    "bad inode number: %lu", inode->i_ino);
		return 0;
	}
	block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
	if (block_group >= inode->i_sb->u.ext2_sb.s_groups_count)
		ext2_panic (inode->i_sb, "ext2_write_inode",
			    "group >= groups count");
	group_desc = block_group / EXT2_DESC_PER_BLOCK(inode->i_sb);
	desc = block_group % EXT2_DESC_PER_BLOCK(inode->i_sb);
	bh = inode->i_sb->u.ext2_sb.s_group_desc[group_desc];
	if (!bh)
		ext2_panic (inode->i_sb, "ext2_write_inode",
			    "Descriptor not loaded");
	gdp = (struct ext2_group_desc *) bh->b_data;
	block = gdp[desc].bg_inode_table +
		(((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb))
		 / EXT2_INODES_PER_BLOCK(inode->i_sb));
#ifndef OS2
	if (!(bh = bread (inode->i_dev, block, inode->i_sb->s_blocksize)))
#else
	if (!(bh = bread (inode->i_sb, block, inode->i_sb->s_blocksize)))
#endif
		ext2_panic (inode->i_sb, "ext2_write_inode",
			    "unable to read i-node block - "
			    "inode=%lu, block=%lu", inode->i_ino, block);
	raw_inode = ((struct ext2_inode *)bh->b_data) +
		(inode->i_ino - 1) % EXT2_INODES_PER_BLOCK(inode->i_sb);
	raw_inode->i_mode = inode->i_mode;
	raw_inode->i_uid = inode->i_uid;
	raw_inode->i_gid = inode->i_gid;
	raw_inode->i_links_count = inode->i_nlink;
	raw_inode->i_size = inode->i_size;
	raw_inode->i_atime = inode->i_atime;
	raw_inode->i_ctime = inode->i_ctime;
	raw_inode->i_mtime = inode->i_mtime;
	raw_inode->i_blocks = inode->i_blocks;
	raw_inode->i_dtime = inode->u.ext2_i.i_dtime;
	raw_inode->i_flags = inode->u.ext2_i.i_flags;
	raw_inode->i_faddr = inode->u.ext2_i.i_faddr;
	raw_inode->i_frag = inode->u.ext2_i.i_frag_no;
	raw_inode->i_fsize = inode->u.ext2_i.i_frag_size;
	raw_inode->i_file_acl = inode->u.ext2_i.i_file_acl;
	raw_inode->i_dir_acl = inode->u.ext2_i.i_dir_acl;
	raw_inode->i_version = inode->u.ext2_i.i_version;
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		raw_inode->i_block[0] = inode->i_rdev;
	else for (block = 0; block < EXT2_N_BLOCKS; block++)
		raw_inode->i_block[block] = inode->u.ext2_i.i_data[block];
	mark_buffer_dirty(bh, 1);
	inode->i_dirt = 0;
	return bh;
}

void ext2_write_inode (struct inode * inode)
{
	struct buffer_head * bh;
	bh = ext2_update_inode (inode);
	brelse (bh);
}

int ext2_sync_inode (struct inode *inode)
{
	int err = 0;
	struct buffer_head *bh;

	bh = ext2_update_inode (inode);
	if (bh && bh->b_dirt)
	{
		ll_rw_block (WRITE, 1, &bh);
		wait_on_buffer (bh);
#ifndef OS2	// ll_rw_block is SYNCHRONOUS on OS/2
		if (bh->b_req && !bh->b_uptodate)
		{
			printk ("IO error syncing ext2 inode [%04x:%08lx]\n",
				inode->i_dev, inode->i_ino);
			err = -1;
		}
#endif
	}
	else if (!bh)
		err = -1;
	brelse (bh);
	return err;
}