resize.c

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/*
 *   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\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 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)\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;

    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\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;
}