/*
 *   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 shrinked;
 */
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;
        uint old_agsize;
        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\n");
                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\n");
                        rc = -EINVAL;
                        goto out;
                }
        } else {
                /* check the device */
                bh = sb_bread(sb, newLVSize - 1);
                if (!bh) {
                        printk(KERN_WARNING "jfs_extendfs: invalid size\n");
                        rc = -EINVAL;
                        goto out;
                }
                bforget(bh);
        }

        /* Can't extend write-protected drive */

        if (isReadOnly(ipbmap)) {
                printk(KERN_WARNING "jfs_extendfs: read-only file system\n");
                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 shrinked */
        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)\n",
                       (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;
        /*
         * 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 (bmp->db_agsize != old_agsize) {
                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\n");
                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;
}