/*
   *   Copyright (C) International Business Machines  Corp., 2000-2004
   *
   *   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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
  
  #include <linux/fs.h>
  #include <linux/buffer_head.h>
  #include <linux/quotaops.h>
  #include "jfs_incore.h"
  #include "jfs_filsys.h"
  #include "jfs_metapage.h"
  #include "jfs_dinode.h"
  #include "jfs_imap.h"
  #include "jfs_dmap.h"
  #include "jfs_superblock.h"
  #include "jfs_txnmgr.h"
  #include "jfs_debug.h"

  #define BITSPERPAGE	(PSIZE << 3)
  #define L2MEGABYTE	20
  #define MEGABYTE	(1 << L2MEGABYTE)
  #define MEGABYTE32	(MEGABYTE << 5)

  
  /* convert block number to bmap file page number */
  #define BLKTODMAPN(b)\

  	(((b) >> 13) + ((b) >> 23) + ((b) >> 33) + 3 + 1)

  
  /*

   *	jfs_extendfs()

   *
   * function: extend file system;
   *
   *   |-------------------------------|----------|----------|
   *   file system space               fsck       inline log
   *                                   workspace  space
   *
   * input:

   *	new LVSize: in LV blocks (required)
   *	new LogSize: in LV blocks (optional)
   *	new FSSize: in LV blocks (optional)

   *
   * new configuration:
   * 1. set new LogSize as specified or default from new LVSize;
   * 2. compute new FSCKSize from new LVSize;
   * 3. set new FSSize as MIN(FSSize, LVSize-(LogSize+FSCKSize)) where
   *    assert(new FSSize >= old FSSize),

   *    i.e., file system must not be shrunk;

   */
  int jfs_extendfs(struct super_block *sb, s64 newLVSize, int newLogSize)
  {
  	int rc = 0;
  	struct jfs_sb_info *sbi = JFS_SBI(sb);
  	struct inode *ipbmap = sbi->ipbmap;
  	struct inode *ipbmap2;
  	struct inode *ipimap = sbi->ipimap;
  	struct jfs_log *log = sbi->log;
  	struct bmap *bmp = sbi->bmap;
  	s64 newLogAddress, newFSCKAddress;
  	int newFSCKSize;
  	s64 newMapSize = 0, mapSize;
  	s64 XAddress, XSize, nblocks, xoff, xaddr, t64;
  	s64 oldLVSize;
  	s64 newFSSize;
  	s64 VolumeSize;
  	int newNpages = 0, nPages, newPage, xlen, t32;
  	int tid;
  	int log_formatted = 0;
  	struct inode *iplist[1];
  	struct jfs_superblock *j_sb, *j_sb2;

  	s64 old_agsize;

  	int agsizechanged = 0;

  	struct buffer_head *bh, *bh2;
  
  	/* If the volume hasn't grown, get out now */
  
  	if (sbi->mntflag & JFS_INLINELOG)
  		oldLVSize = addressPXD(&sbi->logpxd) + lengthPXD(&sbi->logpxd);
  	else
  		oldLVSize = addressPXD(&sbi->fsckpxd) +
  		    lengthPXD(&sbi->fsckpxd);
  
  	if (oldLVSize >= newLVSize) {
  		printk(KERN_WARNING
  		       "jfs_extendfs: volume hasn't grown, returning
  ");
  		goto out;
  	}
  
  	VolumeSize = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
  
  	if (VolumeSize) {
  		if (newLVSize > VolumeSize) {
  			printk(KERN_WARNING "jfs_extendfs: invalid size
  ");
  			rc = -EINVAL;
  			goto out;
  		}
  	} else {
  		/* check the device */
  		bh = sb_bread(sb, newLVSize - 1);
  		if (!bh) {
  			printk(KERN_WARNING "jfs_extendfs: invalid size
  ");
  			rc = -EINVAL;
  			goto out;
  		}
  		bforget(bh);
  	}
  
  	/* Can't extend write-protected drive */
  
  	if (isReadOnly(ipbmap)) {
  		printk(KERN_WARNING "jfs_extendfs: read-only file system
  ");
  		rc = -EROFS;
  		goto out;
  	}
  
  	/*

  	 *	reconfigure LV spaces
  	 *	---------------------

  	 *
  	 * validate new size, or, if not specified, determine new size
  	 */
  
  	/*
  	 * reconfigure inline log space:
  	 */
  	if ((sbi->mntflag & JFS_INLINELOG)) {
  		if (newLogSize == 0) {
  			/*
  			 * no size specified: default to 1/256 of aggregate
  			 * size; rounded up to a megabyte boundary;
  			 */
  			newLogSize = newLVSize >> 8;
  			t32 = (1 << (20 - sbi->l2bsize)) - 1;
  			newLogSize = (newLogSize + t32) & ~t32;
  			newLogSize =
  			    min(newLogSize, MEGABYTE32 >> sbi->l2bsize);
  		} else {
  			/*
  			 * convert the newLogSize to fs blocks.
  			 *
  			 * Since this is given in megabytes, it will always be
  			 * an even number of pages.
  			 */
  			newLogSize = (newLogSize * MEGABYTE) >> sbi->l2bsize;
  		}
  
  	} else
  		newLogSize = 0;
  
  	newLogAddress = newLVSize - newLogSize;
  
  	/*
  	 * reconfigure fsck work space:
  	 *
  	 * configure it to the end of the logical volume regardless of
  	 * whether file system extends to the end of the aggregate;
  	 * Need enough 4k pages to cover:
  	 *  - 1 bit per block in aggregate rounded up to BPERDMAP boundary
  	 *  - 1 extra page to handle control page and intermediate level pages
  	 *  - 50 extra pages for the chkdsk service log
  	 */
  	t64 = ((newLVSize - newLogSize + BPERDMAP - 1) >> L2BPERDMAP)
  	    << L2BPERDMAP;

  	t32 = DIV_ROUND_UP(t64, BITSPERPAGE) + 1 + 50;

  	newFSCKSize = t32 << sbi->l2nbperpage;
  	newFSCKAddress = newLogAddress - newFSCKSize;
  
  	/*
  	 * compute new file system space;
  	 */
  	newFSSize = newLVSize - newLogSize - newFSCKSize;

  	/* file system cannot be shrunk */

  	if (newFSSize < bmp->db_mapsize) {
  		rc = -EINVAL;
  		goto out;
  	}
  
  	/*
  	 * If we're expanding enough that the inline log does not overlap
  	 * the old one, we can format the new log before we quiesce the
  	 * filesystem.
  	 */
  	if ((sbi->mntflag & JFS_INLINELOG) && (newLogAddress > oldLVSize)) {
  		if ((rc = lmLogFormat(log, newLogAddress, newLogSize)))
  			goto out;
  		log_formatted = 1;
  	}
  	/*

  	 *	quiesce file system

  	 *
  	 * (prepare to move the inline log and to prevent map update)
  	 *
  	 * block any new transactions and wait for completion of
  	 * all wip transactions and flush modified pages s.t.
  	 * on-disk file system is in consistent state and
  	 * log is not required for recovery.
  	 */
  	txQuiesce(sb);

  	/* Reset size of direct inode */
  	sbi->direct_inode->i_size =  sb->s_bdev->bd_inode->i_size;

  	if (sbi->mntflag & JFS_INLINELOG) {
  		/*
  		 * deactivate old inline log
  		 */
  		lmLogShutdown(log);
  
  		/*
  		 * mark on-disk super block for fs in transition;
  		 *
  		 * update on-disk superblock for the new space configuration
  		 * of inline log space and fsck work space descriptors:
  		 * N.B. FS descriptor is NOT updated;
  		 *
  		 * crash recovery:
  		 * logredo(): if FM_EXTENDFS, return to fsck() for cleanup;
  		 * fsck(): if FM_EXTENDFS, reformat inline log and fsck
  		 * workspace from superblock inline log descriptor and fsck
  		 * workspace descriptor;
  		 */
  
  		/* read in superblock */
  		if ((rc = readSuper(sb, &bh)))
  			goto error_out;
  		j_sb = (struct jfs_superblock *)bh->b_data;
  
  		/* mark extendfs() in progress */
  		j_sb->s_state |= cpu_to_le32(FM_EXTENDFS);
  		j_sb->s_xsize = cpu_to_le64(newFSSize);
  		PXDaddress(&j_sb->s_xfsckpxd, newFSCKAddress);
  		PXDlength(&j_sb->s_xfsckpxd, newFSCKSize);
  		PXDaddress(&j_sb->s_xlogpxd, newLogAddress);
  		PXDlength(&j_sb->s_xlogpxd, newLogSize);
  
  		/* synchronously update superblock */
  		mark_buffer_dirty(bh);
  		sync_dirty_buffer(bh);
  		brelse(bh);
  
  		/*
  		 * format new inline log synchronously;
  		 *
  		 * crash recovery: if log move in progress,
  		 * reformat log and exit success;
  		 */
  		if (!log_formatted)
  			if ((rc = lmLogFormat(log, newLogAddress, newLogSize)))
  				goto error_out;
  
  		/*
  		 * activate new log
  		 */
  		log->base = newLogAddress;
  		log->size = newLogSize >> (L2LOGPSIZE - sb->s_blocksize_bits);
  		if ((rc = lmLogInit(log)))
  			goto error_out;
  	}
  
  	/*

  	 *	extend block allocation map
  	 *	---------------------------

  	 *
  	 * extendfs() for new extension, retry after crash recovery;
  	 *
  	 * note: both logredo() and fsck() rebuild map from
  	 * the bitmap and configuration parameter from superblock
  	 * (disregarding all other control information in the map);
  	 *
  	 * superblock:
  	 *  s_size: aggregate size in physical blocks;
  	 */
  	/*

  	 *	compute the new block allocation map configuration

  	 *
  	 * map dinode:
  	 *  di_size: map file size in byte;
  	 *  di_nblocks: number of blocks allocated for map file;
  	 *  di_mapsize: number of blocks in aggregate (covered by map);
  	 * map control page:
  	 *  db_mapsize: number of blocks in aggregate (covered by map);
  	 */
  	newMapSize = newFSSize;
  	/* number of data pages of new bmap file:
  	 * roundup new size to full dmap page boundary and
  	 * add 1 extra dmap page for next extendfs()
  	 */
  	t64 = (newMapSize - 1) + BPERDMAP;
  	newNpages = BLKTODMAPN(t64) + 1;
  
  	/*

  	 *	extend map from current map (WITHOUT growing mapfile)

  	 *
  	 * map new extension with unmapped part of the last partial
  	 * dmap page, if applicable, and extra page(s) allocated
  	 * at end of bmap by mkfs() or previous extendfs();
  	 */
        extendBmap:
  	/* compute number of blocks requested to extend */
  	mapSize = bmp->db_mapsize;
  	XAddress = mapSize;	/* eXtension Address */
  	XSize = newMapSize - mapSize;	/* eXtension Size */
  	old_agsize = bmp->db_agsize;	/* We need to know if this changes */
  
  	/* compute number of blocks that can be extended by current mapfile */
  	t64 = dbMapFileSizeToMapSize(ipbmap);
  	if (mapSize > t64) {
  		printk(KERN_ERR "jfs_extendfs: mapSize (0x%Lx) > t64 (0x%Lx)
  ",
  		       (long long) mapSize, (long long) t64);
  		rc = -EIO;
  		goto error_out;
  	}
  	nblocks = min(t64 - mapSize, XSize);
  
  	/*
  	 * update map pages for new extension:
  	 *
  	 * update/init dmap and bubble up the control hierarchy
  	 * incrementally fold up dmaps into upper levels;
  	 * update bmap control page;
  	 */
  	if ((rc = dbExtendFS(ipbmap, XAddress, nblocks)))
  		goto error_out;

  
  	agsizechanged |= (bmp->db_agsize != old_agsize);

  	/*
  	 * the map now has extended to cover additional nblocks:
  	 * dn_mapsize = oldMapsize + nblocks;
  	 */
  	/* ipbmap->i_mapsize += nblocks; */
  	XSize -= nblocks;
  
  	/*

  	 *	grow map file to cover remaining extension
  	 *	and/or one extra dmap page for next extendfs();

  	 *
  	 * allocate new map pages and its backing blocks, and
  	 * update map file xtree
  	 */
  	/* compute number of data pages of current bmap file */
  	nPages = ipbmap->i_size >> L2PSIZE;
  
  	/* need to grow map file ? */
  	if (nPages == newNpages)
  		goto finalizeBmap;
  
  	/*
  	 * grow bmap file for the new map pages required:
  	 *
  	 * allocate growth at the start of newly extended region;
  	 * bmap file only grows sequentially, i.e., both data pages
  	 * and possibly xtree index pages may grow in append mode,
  	 * s.t. logredo() can reconstruct pre-extension state
  	 * by washing away bmap file of pages outside s_size boundary;
  	 */
  	/*
  	 * journal map file growth as if a regular file growth:
  	 * (note: bmap is created with di_mode = IFJOURNAL|IFREG);
  	 *
  	 * journaling of bmap file growth is not required since
  	 * logredo() do/can not use log records of bmap file growth
  	 * but it provides careful write semantics, pmap update, etc.;
  	 */
  	/* synchronous write of data pages: bmap data pages are
  	 * cached in meta-data cache, and not written out
  	 * by txCommit();
  	 */
  	filemap_fdatawait(ipbmap->i_mapping);

  	filemap_write_and_wait(ipbmap->i_mapping);

  	diWriteSpecial(ipbmap, 0);
  
  	newPage = nPages;	/* first new page number */
  	xoff = newPage << sbi->l2nbperpage;
  	xlen = (newNpages - nPages) << sbi->l2nbperpage;
  	xlen = min(xlen, (int) nblocks) & ~(sbi->nbperpage - 1);
  	xaddr = XAddress;
  
  	tid = txBegin(sb, COMMIT_FORCE);
  
  	if ((rc = xtAppend(tid, ipbmap, 0, xoff, nblocks, &xlen, &xaddr, 0))) {
  		txEnd(tid);
  		goto error_out;
  	}
  	/* update bmap file size */
  	ipbmap->i_size += xlen << sbi->l2bsize;
  	inode_add_bytes(ipbmap, xlen << sbi->l2bsize);
  
  	iplist[0] = ipbmap;
  	rc = txCommit(tid, 1, &iplist[0], COMMIT_FORCE);
  
  	txEnd(tid);
  
  	if (rc)
  		goto error_out;
  
  	/*
  	 * map file has been grown now to cover extension to further out;
  	 * di_size = new map file size;
  	 *
  	 * if huge extension, the previous extension based on previous
  	 * map file size may not have been sufficient to cover whole extension
  	 * (it could have been used up for new map pages),
  	 * but the newly grown map file now covers lot bigger new free space
  	 * available for further extension of map;
  	 */
  	/* any more blocks to extend ? */
  	if (XSize)
  		goto extendBmap;
  
        finalizeBmap:
  	/* finalize bmap */
  	dbFinalizeBmap(ipbmap);
  
  	/*

  	 *	update inode allocation map
  	 *	---------------------------

  	 *
  	 * move iag lists from old to new iag;
  	 * agstart field is not updated for logredo() to reconstruct
  	 * iag lists if system crash occurs.
  	 * (computation of ag number from agstart based on agsize
  	 * will correctly identify the new ag);
  	 */
  	/* if new AG size the same as old AG size, done! */

  	if (agsizechanged) {

  		if ((rc = diExtendFS(ipimap, ipbmap)))
  			goto error_out;
  
  		/* finalize imap */
  		if ((rc = diSync(ipimap)))
  			goto error_out;
  	}
  
  	/*

  	 *	finalize
  	 *	--------

  	 *
  	 * extension is committed when on-disk super block is
  	 * updated with new descriptors: logredo will recover
  	 * crash before it to pre-extension state;
  	 */
  
  	/* sync log to skip log replay of bmap file growth transaction; */
  	/* lmLogSync(log, 1); */
  
  	/*
  	 * synchronous write bmap global control page;
  	 * for crash before completion of write
  	 * logredo() will recover to pre-extendfs state;
  	 * for crash after completion of write,
  	 * logredo() will recover post-extendfs state;
  	 */
  	if ((rc = dbSync(ipbmap)))
  		goto error_out;
  
  	/*
  	 * copy primary bmap inode to secondary bmap inode
  	 */
  
  	ipbmap2 = diReadSpecial(sb, BMAP_I, 1);
  	if (ipbmap2 == NULL) {
  		printk(KERN_ERR "jfs_extendfs: diReadSpecial(bmap) failed
  ");
  		goto error_out;
  	}
  	memcpy(&JFS_IP(ipbmap2)->i_xtroot, &JFS_IP(ipbmap)->i_xtroot, 288);
  	ipbmap2->i_size = ipbmap->i_size;
  	ipbmap2->i_blocks = ipbmap->i_blocks;
  
  	diWriteSpecial(ipbmap2, 1);
  	diFreeSpecial(ipbmap2);
  
  	/*

  	 *	update superblock

  	 */
  	if ((rc = readSuper(sb, &bh)))
  		goto error_out;
  	j_sb = (struct jfs_superblock *)bh->b_data;
  
  	/* mark extendfs() completion */
  	j_sb->s_state &= cpu_to_le32(~FM_EXTENDFS);
  	j_sb->s_size = cpu_to_le64(bmp->db_mapsize <<
  				   le16_to_cpu(j_sb->s_l2bfactor));
  	j_sb->s_agsize = cpu_to_le32(bmp->db_agsize);
  
  	/* update inline log space descriptor */
  	if (sbi->mntflag & JFS_INLINELOG) {
  		PXDaddress(&(j_sb->s_logpxd), newLogAddress);
  		PXDlength(&(j_sb->s_logpxd), newLogSize);
  	}
  
  	/* record log's mount serial number */
  	j_sb->s_logserial = cpu_to_le32(log->serial);
  
  	/* update fsck work space descriptor */
  	PXDaddress(&(j_sb->s_fsckpxd), newFSCKAddress);
  	PXDlength(&(j_sb->s_fsckpxd), newFSCKSize);
  	j_sb->s_fscklog = 1;
  	/* sb->s_fsckloglen remains the same */
  
  	/* Update secondary superblock */
  	bh2 = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
  	if (bh2) {
  		j_sb2 = (struct jfs_superblock *)bh2->b_data;
  		memcpy(j_sb2, j_sb, sizeof (struct jfs_superblock));
  
  		mark_buffer_dirty(bh);
  		sync_dirty_buffer(bh2);
  		brelse(bh2);
  	}
  
  	/* write primary superblock */
  	mark_buffer_dirty(bh);
  	sync_dirty_buffer(bh);
  	brelse(bh);
  
  	goto resume;
  
        error_out:
  	jfs_error(sb, "jfs_extendfs");
  
        resume:
  	/*

  	 *	resume file system transactions

  	 */
  	txResume(sb);
  
        out:
  	return rc;
  }