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/*

 *   Copyright (c) International Business Machines Corp., 2000-2003

 *

 *   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

 */

/*

 * Module: jfs_mount.c

 *

 * note: file system in transition to aggregate/fileset:

 *

 * file system mount is interpreted as the mount of aggregate,

 * if not already mounted, and mount of the single/only fileset in

 * the aggregate;

 *

 * a file system/aggregate is represented by an internal inode

 * (aka mount inode) initialized with aggregate superblock;

 * each vfs represents a fileset, and points to its "fileset inode

 * allocation map inode" (aka fileset inode):

 * (an aggregate itself is structured recursively as a filset:

 * an internal vfs is constructed and points to its "fileset inode

 * allocation map inode" (aka aggregate inode) where each inode

 * represents a fileset inode) so that inode number is mapped to

 * on-disk inode in uniform way at both aggregate and fileset level;

 *

 * each vnode/inode of a fileset is linked to its vfs (to facilitate

 * per fileset inode operations, e.g., unmount of a fileset, etc.);

 * each inode points to the mount inode (to facilitate access to

 * per aggregate information, e.g., block size, etc.) as well as

 * its file set inode.

 *

 *   aggregate

 *   ipmnt

 *   mntvfs -> fileset ipimap+ -> aggregate ipbmap -> aggregate ipaimap;

 *             fileset vfs     -> vp(1) <-> ... <-> vp(n) <->vproot;

 */

#include <linux/fs.h>

#include <linux/locks.h>

#include "jfs_incore.h"

#include "jfs_filsys.h"

#include "jfs_superblock.h"

#include "jfs_dmap.h"

#include "jfs_imap.h"

#include "jfs_metapage.h"

#include "jfs_debug.h"

/*

 * forward references

 */

static int chkSuper(struct super_block *);

static int logMOUNT(struct super_block *sb);

/*

 * NAME:        jfs_mount(sb)

 *

 * FUNCTION:    vfs_mount()

 *

 * PARAMETER:   sb      - super block

 *

 * RETURN:      -EBUSY  - device already mounted or open for write

 *              -EBUSY  - cvrdvp already mounted;

 *              -EBUSY  - mount table full

 *              -ENOTDIR- cvrdvp not directory on a device mount

 *              -ENXIO  - device open failure

 */

int jfs_mount(struct super_block *sb)

{

        int rc = 0;              /* Return code          */

        struct jfs_sb_info *sbi = JFS_SBI(sb);

        struct inode *ipaimap = NULL;

        struct inode *ipaimap2 = NULL;

        struct inode *ipimap = NULL;

        struct inode *ipbmap = NULL;

        /*

         * read/validate superblock

         * (initialize mount inode from the superblock)

         */

        if ((rc = chkSuper(sb))) {

                goto errout20;

        }

        ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);

        if (ipaimap == NULL) {

                jfs_err("jfs_mount: Faild to read AGGREGATE_I");

                rc = -EIO;

                goto errout20;

        }

        sbi->ipaimap = ipaimap;

        jfs_info("jfs_mount: ipaimap:0x%p", ipaimap);

        /*

         * initialize aggregate inode allocation map

         */

        if ((rc = diMount(ipaimap))) {

                jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);

                goto errout21;

        }

        /*

         * open aggregate block allocation map

         */

        ipbmap = diReadSpecial(sb, BMAP_I, 0);

        if (ipbmap == NULL) {

                rc = -EIO;

                goto errout22;

        }

        jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);

        sbi->ipbmap = ipbmap;

        /*

         * initialize aggregate block allocation map

         */

        if ((rc = dbMount(ipbmap))) {

                jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);

                goto errout22;

        }

        /*

         * open the secondary aggregate inode allocation map

         *

         * This is a duplicate of the aggregate inode allocation map.

         *

         * hand craft a vfs in the same fashion as we did to read ipaimap.

         * By adding INOSPEREXT (32) to the inode number, we are telling

         * diReadSpecial that we are reading from the secondary aggregate

         * inode table.  This also creates a unique entry in the inode hash

         * table.

         */

        if ((sbi->mntflag & JFS_BAD_SAIT) == 0) {

                ipaimap2 = diReadSpecial(sb, AGGREGATE_I, 1);

                if (ipaimap2 == 0) {

                        jfs_err("jfs_mount: Faild to read AGGREGATE_I");

                        rc = -EIO;

                        goto errout35;

                }

                sbi->ipaimap2 = ipaimap2;

                jfs_info("jfs_mount: ipaimap2:0x%p", ipaimap2);

                /*

                 * initialize secondary aggregate inode allocation map

                 */

                if ((rc = diMount(ipaimap2))) {

                        jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",

                                rc);

                        goto errout35;

                }

        } else

                /* Secondary aggregate inode table is not valid */

                sbi->ipaimap2 = 0;

        /*

         *      mount (the only/single) fileset

         */

        /*

         * open fileset inode allocation map (aka fileset inode)

         */

        ipimap = diReadSpecial(sb, FILESYSTEM_I, 0);

        if (ipimap == NULL) {

                jfs_err("jfs_mount: Failed to read FILESYSTEM_I");

                /* open fileset secondary inode allocation map */

                rc = -EIO;

                goto errout40;

        }

        jfs_info("jfs_mount: ipimap:0x%p", ipimap);

        /* map further access of per fileset inodes by the fileset inode */

        sbi->ipimap = ipimap;

        /* initialize fileset inode allocation map */

        if ((rc = diMount(ipimap))) {

                jfs_err("jfs_mount: diMount failed w/rc = %d", rc);

                goto errout41;

        }

        goto out;

        /*

         *      unwind on error

         */

//errout42: /* close fileset inode allocation map */

        diUnmount(ipimap, 1);

      errout41:         /* close fileset inode allocation map inode */

        diFreeSpecial(ipimap);

      errout40:         /* fileset closed */

        /* close secondary aggregate inode allocation map */

        if (ipaimap2) {

                diUnmount(ipaimap2, 1);

                diFreeSpecial(ipaimap2);

        }

      errout35:

        /* close aggregate block allocation map */

        dbUnmount(ipbmap, 1);

        diFreeSpecial(ipbmap);

      errout22:         /* close aggregate inode allocation map */

        diUnmount(ipaimap, 1);

      errout21:         /* close aggregate inodes */

        diFreeSpecial(ipaimap);

      errout20:         /* aggregate closed */

      out:

        if (rc)

                jfs_err("Mount JFS Failure: %d", rc);

        return rc;

}

/*

 * NAME:        jfs_mount_rw(sb, remount)

 *

 * FUNCTION:    Completes read-write mount, or remounts read-only volume

 *              as read-write

 */

int jfs_mount_rw(struct super_block *sb, int remount)

{

        struct jfs_sb_info *sbi = JFS_SBI(sb);

        struct jfs_log *log;

        int rc;

        /*

         * If we are re-mounting a previously read-only volume, we want to

         * re-read the inode and block maps, since fsck.jfs may have updated

         * them.

         */

        if (remount) {

                if (chkSuper(sb) || (sbi->state != FM_CLEAN))

                        return -EINVAL;

                truncate_inode_pages(sbi->ipimap->i_mapping, 0);

                truncate_inode_pages(sbi->ipbmap->i_mapping, 0);

                diUnmount(sbi->ipimap, 1);

                if ((rc = diMount(sbi->ipimap))) {

                        jfs_err("jfs_mount_rw: diMount failed!");

                        return rc;

                }

                dbUnmount(sbi->ipbmap, 1);

                if ((rc = dbMount(sbi->ipbmap))) {

                        jfs_err("jfs_mount_rw: dbMount failed!");

                        return rc;

                }

        }

        /*

         * open/initialize log

         */

        if ((rc = lmLogOpen(sb, &log)))

                return rc;

        JFS_SBI(sb)->log = log;

        /*

         * update file system superblock;

         */

        if ((rc = updateSuper(sb, FM_MOUNT))) {

                jfs_err("jfs_mount: updateSuper failed w/rc = %d", rc);

                lmLogClose(sb, log);

                JFS_SBI(sb)->log = 0;

                return rc;

        }

        /*

         * write MOUNT log record of the file system

         */

        logMOUNT(sb);

        return rc;

}

/*

 *      chkSuper()

 *

 * validate the superblock of the file system to be mounted and

 * get the file system parameters.

 *

 * returns

 *      0 with fragsize set if check successful

 *      error code if not successful

 */

static int chkSuper(struct super_block *sb)

{

        int rc = 0;

        struct jfs_sb_info *sbi = JFS_SBI(sb);

        struct jfs_superblock *j_sb;

        struct buffer_head *bh;

        int AIM_bytesize, AIT_bytesize;

        int expected_AIM_bytesize, expected_AIT_bytesize;

        s64 AIM_byte_addr, AIT_byte_addr, fsckwsp_addr;

        s64 byte_addr_diff0, byte_addr_diff1;

        s32 bsize;

        if ((rc = readSuper(sb, &bh)))

                return rc;

        j_sb = (struct jfs_superblock *)bh->b_data;

        /*

         * validate superblock

         */

        /* validate fs signature */

        if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||

            j_sb->s_version > cpu_to_le32(JFS_VERSION)) {

                rc = -EINVAL;

                goto out;

        }

        bsize = le32_to_cpu(j_sb->s_bsize);

#ifdef _JFS_4K

        if (bsize != PSIZE) {

                jfs_err("Currently only 4K block size supported!");

                rc = -EINVAL;

                goto out;

        }

#endif                          /* _JFS_4K */

        jfs_info("superblock: flag:0x%08x state:0x%08x size:0x%Lx",

                 le32_to_cpu(j_sb->s_flag), le32_to_cpu(j_sb->s_state),

                 (unsigned long long) le64_to_cpu(j_sb->s_size));

        /* validate the descriptors for Secondary AIM and AIT */

        if ((j_sb->s_flag & cpu_to_le32(JFS_BAD_SAIT)) !=

            cpu_to_le32(JFS_BAD_SAIT)) {

                expected_AIM_bytesize = 2 * PSIZE;

                AIM_bytesize = lengthPXD(&(j_sb->s_aim2)) * bsize;

                expected_AIT_bytesize = 4 * PSIZE;

                AIT_bytesize = lengthPXD(&(j_sb->s_ait2)) * bsize;

                AIM_byte_addr = addressPXD(&(j_sb->s_aim2)) * bsize;

                AIT_byte_addr = addressPXD(&(j_sb->s_ait2)) * bsize;

                byte_addr_diff0 = AIT_byte_addr - AIM_byte_addr;

                fsckwsp_addr = addressPXD(&(j_sb->s_fsckpxd)) * bsize;

                byte_addr_diff1 = fsckwsp_addr - AIT_byte_addr;

                if ((AIM_bytesize != expected_AIM_bytesize) ||

                    (AIT_bytesize != expected_AIT_bytesize) ||

                    (byte_addr_diff0 != AIM_bytesize) ||

                    (byte_addr_diff1 <= AIT_bytesize))

                        j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);

        }

        if ((j_sb->s_flag & cpu_to_le32(JFS_GROUPCOMMIT)) !=

            cpu_to_le32(JFS_GROUPCOMMIT))

                j_sb->s_flag |= cpu_to_le32(JFS_GROUPCOMMIT);

        /* validate fs state */

        if (j_sb->s_state != cpu_to_le32(FM_CLEAN) &&

            !(sb->s_flags & MS_RDONLY)) {

                jfs_err("jfs_mount: Mount Failure: File System Dirty.");

                rc = -EINVAL;

                goto out;

        }

        sbi->state = le32_to_cpu(j_sb->s_state);

        sbi->mntflag = le32_to_cpu(j_sb->s_flag);

        /*

         * JFS always does I/O by 4K pages.  Don't tell the buffer cache

         * that we use anything else (leave s_blocksize alone).

         */

        sbi->bsize = bsize;

        sbi->l2bsize = le16_to_cpu(j_sb->s_l2bsize);

        /*

         * For now, ignore s_pbsize, l2bfactor.  All I/O going through buffer

         * cache.

         */

        sbi->nbperpage = PSIZE >> sbi->l2bsize;

        sbi->l2nbperpage = L2PSIZE - sbi->l2bsize;

        sbi->l2niperblk = sbi->l2bsize - L2DISIZE;

        if (sbi->mntflag & JFS_INLINELOG)

                sbi->logpxd = j_sb->s_logpxd;

        else {

                sbi->logdev = to_kdev_t(le32_to_cpu(j_sb->s_logdev));

                memcpy(sbi->uuid, j_sb->s_uuid, sizeof(sbi->uuid));

                memcpy(sbi->loguuid, j_sb->s_loguuid, sizeof(sbi->uuid));

        }

        sbi->fsckpxd = j_sb->s_fsckpxd;

        sbi->ait2 = j_sb->s_ait2;

      out:

        brelse(bh);

        return rc;

}

/*

 *      updateSuper()

 *

 * update synchronously superblock if it is mounted read-write.

 */

int updateSuper(struct super_block *sb, uint state)

{

        struct jfs_superblock *j_sb;

        struct jfs_sb_info *sbi = JFS_SBI(sb);

        struct buffer_head *bh;

        int rc;

        if (sbi->flag & JFS_NOINTEGRITY) {

                if (state == FM_DIRTY) {

                        sbi->p_state = state;

                        return 0;

                } else if (state == FM_MOUNT) {

                        sbi->p_state = sbi->state;

                        state = FM_DIRTY;

                } else if (state == FM_CLEAN) {

                        state = sbi->p_state;

                } else

                        jfs_err("updateSuper: bad state");

        } else if (sbi->state == FM_DIRTY)

                return 0;

        if ((rc = readSuper(sb, &bh)))

                return rc;

        j_sb = (struct jfs_superblock *)bh->b_data;

        j_sb->s_state = cpu_to_le32(state);

        sbi->state = state;

        if (state == FM_MOUNT) {

                /* record log's dev_t and mount serial number */

                j_sb->s_logdev = cpu_to_le32(sbi->log->bdev->bd_dev);

                j_sb->s_logserial = cpu_to_le32(sbi->log->serial);

        } else if (state == FM_CLEAN) {

                /*

                 * If this volume is shared with OS/2, OS/2 will need to

                 * recalculate DASD usage, since we don't deal with it.

                 */

                if (j_sb->s_flag & cpu_to_le32(JFS_DASD_ENABLED))

                        j_sb->s_flag |= cpu_to_le32(JFS_DASD_PRIME);

        }

        mark_buffer_dirty(bh);

        ll_rw_block(WRITE, 1, &bh);

        wait_on_buffer(bh);

        brelse(bh);

        return 0;

}

/*

 *      readSuper()

 *

 * read superblock by raw sector address

 */

int readSuper(struct super_block *sb, struct buffer_head **bpp)

{

        /* read in primary superblock */

        *bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);

        if (*bpp)

                return 0;

        /* read in secondary/replicated superblock */

        *bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);

        if (*bpp)

                return 0;

        return -EIO;

}

/*

 *      logMOUNT()

 *

 * function: write a MOUNT log record for file system.

 *

 * MOUNT record keeps logredo() from processing log records

 * for this file system past this point in log.

 * it is harmless if mount fails.

 *

 * note: MOUNT record is at aggregate level, not at fileset level,

 * since log records of previous mounts of a fileset

 * (e.g., AFTER record of extent allocation) have to be processed

 * to update block allocation map at aggregate level.

 */

static int logMOUNT(struct super_block *sb)

{

        struct jfs_log *log = JFS_SBI(sb)->log;

        struct lrd lrd;

        lrd.logtid = 0;

        lrd.backchain = 0;

        lrd.type = cpu_to_le16(LOG_MOUNT);

        lrd.length = 0;

        lrd.aggregate = cpu_to_le32(kdev_t_to_nr(sb->s_dev));

        lmLog(log, NULL, &lrd, NULL);

        return 0;

}