e2fsck: add optimization for heavily hard-linked file systems

[thirdparty/e2fsprogs.git] / e2fsck / journal.c

/*
 * journal.c --- code for handling the "ext3" journal
 *
 * Copyright (C) 2000 Andreas Dilger
 * Copyright (C) 2000 Theodore Ts'o
 *
 * Parts of the code are based on fs/jfs/journal.c by Stephen C. Tweedie
 * Copyright (C) 1999 Red Hat Software
 *
 * This file may be redistributed under the terms of the
 * GNU General Public License version 2 or at your discretion
 * any later version.
 */

#include "config.h"
#ifdef HAVE_SYS_MOUNT_H
#include <sys/param.h>
#include <sys/mount.h>
#define MNT_FL (MS_MGC_VAL | MS_RDONLY)
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif

#define E2FSCK_INCLUDE_INLINE_FUNCS
#include "jfs_user.h"
#include "problem.h"
#include "uuid/uuid.h"

#ifdef CONFIG_JBD_DEBUG         /* Enabled by configure --enable-jfs-debug */
static int bh_count = 0;
#endif

/*
 * Define USE_INODE_IO to use the inode_io.c / fileio.c codepaths.
 * This creates a larger static binary, and a smaller binary using
 * shared libraries.  It's also probably slightly less CPU-efficient,
 * which is why it's not on by default.  But, it's a good way of
 * testing the functions in inode_io.c and fileio.c.
 */
#undef USE_INODE_IO

/* Checksumming functions */
static int e2fsck_journal_verify_csum_type(journal_t *j,
                                           journal_superblock_t *jsb)
{
        if (!journal_has_csum_v2or3(j))
                return 1;

        return jsb->s_checksum_type == JBD2_CRC32C_CHKSUM;
}

static __u32 e2fsck_journal_sb_csum(journal_superblock_t *jsb)
{
        __u32 crc, old_crc;

        old_crc = jsb->s_checksum;
        jsb->s_checksum = 0;
        crc = ext2fs_crc32c_le(~0, (unsigned char *)jsb,
                               sizeof(journal_superblock_t));
        jsb->s_checksum = old_crc;

        return crc;
}

static int e2fsck_journal_sb_csum_verify(journal_t *j,
                                         journal_superblock_t *jsb)
{
        __u32 provided, calculated;

        if (!journal_has_csum_v2or3(j))
                return 1;

        provided = ext2fs_be32_to_cpu(jsb->s_checksum);
        calculated = e2fsck_journal_sb_csum(jsb);

        return provided == calculated;
}

static errcode_t e2fsck_journal_sb_csum_set(journal_t *j,
                                            journal_superblock_t *jsb)
{
        __u32 crc;

        if (!journal_has_csum_v2or3(j))
                return 0;

        crc = e2fsck_journal_sb_csum(jsb);
        jsb->s_checksum = ext2fs_cpu_to_be32(crc);
        return 0;
}

/* Kernel compatibility functions for handling the journal.  These allow us
 * to use the recovery.c file virtually unchanged from the kernel, so we
 * don't have to do much to keep kernel and user recovery in sync.
 */
int journal_bmap(journal_t *journal, blk64_t block, unsigned long long *phys)
{
#ifdef USE_INODE_IO
        *phys = block;
        return 0;
#else
        struct inode    *inode = journal->j_inode;
        errcode_t       retval;
        blk64_t         pblk;

        if (!inode) {
                *phys = block;
                return 0;
        }

        retval= ext2fs_bmap2(inode->i_ctx->fs, inode->i_ino,
                             &inode->i_ext2, NULL, 0, block, 0, &pblk);
        *phys = pblk;
        return (int) retval;
#endif
}

struct buffer_head *getblk(kdev_t kdev, blk64_t blocknr, int blocksize)
{
        struct buffer_head *bh;
        int bufsize = sizeof(*bh) + kdev->k_ctx->fs->blocksize -
                sizeof(bh->b_data);

        bh = e2fsck_allocate_memory(kdev->k_ctx, bufsize, "block buffer");
        if (!bh)
                return NULL;

#ifdef CONFIG_JBD_DEBUG
        if (journal_enable_debug >= 3)
                bh_count++;
#endif
        jfs_debug(4, "getblk for block %llu (%d bytes)(total %d)\n",
                  (unsigned long long) blocknr, blocksize, bh_count);

        bh->b_ctx = kdev->k_ctx;
        if (kdev->k_dev == K_DEV_FS)
                bh->b_io = kdev->k_ctx->fs->io;
        else
                bh->b_io = kdev->k_ctx->journal_io;
        bh->b_size = blocksize;
        bh->b_blocknr = blocknr;

        return bh;
}

int sync_blockdev(kdev_t kdev)
{
        io_channel      io;

        if (kdev->k_dev == K_DEV_FS)
                io = kdev->k_ctx->fs->io;
        else
                io = kdev->k_ctx->journal_io;

        return io_channel_flush(io) ? EIO : 0;
}

void ll_rw_block(int rw, int nr, struct buffer_head *bhp[])
{
        errcode_t retval;
        struct buffer_head *bh;

        for (; nr > 0; --nr) {
                bh = *bhp++;
                if (rw == READ && !bh->b_uptodate) {
                        jfs_debug(3, "reading block %llu/%p\n",
                                  bh->b_blocknr, (void *) bh);
                        retval = io_channel_read_blk64(bh->b_io,
                                                     bh->b_blocknr,
                                                     1, bh->b_data);
                        if (retval) {
                                com_err(bh->b_ctx->device_name, retval,
                                        "while reading block %llu\n",
                                        bh->b_blocknr);
                                bh->b_err = (int) retval;
                                continue;
                        }
                        bh->b_uptodate = 1;
                } else if (rw == WRITE && bh->b_dirty) {
                        jfs_debug(3, "writing block %llu/%p\n",
                                  bh->b_blocknr,
                                  (void *) bh);
                        retval = io_channel_write_blk64(bh->b_io,
                                                      bh->b_blocknr,
                                                      1, bh->b_data);
                        if (retval) {
                                com_err(bh->b_ctx->device_name, retval,
                                        "while writing block %llu\n",
                                        bh->b_blocknr);
                                bh->b_err = (int) retval;
                                continue;
                        }
                        bh->b_dirty = 0;
                        bh->b_uptodate = 1;
                } else {
                        jfs_debug(3, "no-op %s for block %llu\n",
                                  rw == READ ? "read" : "write",
                                  bh->b_blocknr);
                }
        }
}

void mark_buffer_dirty(struct buffer_head *bh)
{
        bh->b_dirty = 1;
}

static void mark_buffer_clean(struct buffer_head * bh)
{
        bh->b_dirty = 0;
}

void brelse(struct buffer_head *bh)
{
        if (bh->b_dirty)
                ll_rw_block(WRITE, 1, &bh);
        jfs_debug(3, "freeing block %llu/%p (total %d)\n",
                  bh->b_blocknr, (void *) bh, --bh_count);
        ext2fs_free_mem(&bh);
}

int buffer_uptodate(struct buffer_head *bh)
{
        return bh->b_uptodate;
}

void mark_buffer_uptodate(struct buffer_head *bh, int val)
{
        bh->b_uptodate = val;
}

void wait_on_buffer(struct buffer_head *bh)
{
        if (!bh->b_uptodate)
                ll_rw_block(READ, 1, &bh);
}


static void e2fsck_clear_recover(e2fsck_t ctx, int error)
{
        ext2fs_clear_feature_journal_needs_recovery(ctx->fs->super);

        /* if we had an error doing journal recovery, we need a full fsck */
        if (error)
                ctx->fs->super->s_state &= ~EXT2_VALID_FS;
        ext2fs_mark_super_dirty(ctx->fs);
}

/*
 * This is a helper function to check the validity of the journal.
 */
struct process_block_struct {
        e2_blkcnt_t     last_block;
};

static int process_journal_block(ext2_filsys fs,
                                 blk64_t        *block_nr,
                                 e2_blkcnt_t blockcnt,
                                 blk64_t ref_block EXT2FS_ATTR((unused)),
                                 int ref_offset EXT2FS_ATTR((unused)),
                                 void *priv_data)
{
        struct process_block_struct *p;
        blk64_t blk = *block_nr;

        p = (struct process_block_struct *) priv_data;

        if (!blk || blk < fs->super->s_first_data_block ||
            blk >= ext2fs_blocks_count(fs->super))
                return BLOCK_ABORT;

        if (blockcnt >= 0)
                p->last_block = blockcnt;
        return 0;
}

static errcode_t e2fsck_get_journal(e2fsck_t ctx, journal_t **ret_journal)
{
        struct process_block_struct pb;
        struct ext2_super_block *sb = ctx->fs->super;
        struct ext2_super_block jsuper;
        struct problem_context  pctx;
        struct buffer_head      *bh;
        struct inode            *j_inode = NULL;
        struct kdev_s           *dev_fs = NULL, *dev_journal;
        const char              *journal_name = 0;
        journal_t               *journal = NULL;
        errcode_t               retval = 0;
        io_manager              io_ptr = 0;
        unsigned long long      start = 0;
        int                     ext_journal = 0;
        int                     tried_backup_jnl = 0;

        clear_problem_context(&pctx);

        journal = e2fsck_allocate_memory(ctx, sizeof(journal_t), "journal");
        if (!journal) {
                return EXT2_ET_NO_MEMORY;
        }

        dev_fs = e2fsck_allocate_memory(ctx, 2*sizeof(struct kdev_s), "kdev");
        if (!dev_fs) {
                retval = EXT2_ET_NO_MEMORY;
                goto errout;
        }
        dev_journal = dev_fs+1;

        dev_fs->k_ctx = dev_journal->k_ctx = ctx;
        dev_fs->k_dev = K_DEV_FS;
        dev_journal->k_dev = K_DEV_JOURNAL;

        journal->j_dev = dev_journal;
        journal->j_fs_dev = dev_fs;
        journal->j_inode = NULL;
        journal->j_blocksize = ctx->fs->blocksize;

        if (uuid_is_null(sb->s_journal_uuid)) {
                if (!sb->s_journal_inum) {
                        retval = EXT2_ET_BAD_INODE_NUM;
                        goto errout;
                }
                j_inode = e2fsck_allocate_memory(ctx, sizeof(*j_inode),
                                                 "journal inode");
                if (!j_inode) {
                        retval = EXT2_ET_NO_MEMORY;
                        goto errout;
                }

                j_inode->i_ctx = ctx;
                j_inode->i_ino = sb->s_journal_inum;

                if ((retval = ext2fs_read_inode(ctx->fs,
                                                sb->s_journal_inum,
                                                &j_inode->i_ext2))) {
                try_backup_journal:
                        if (sb->s_jnl_backup_type != EXT3_JNL_BACKUP_BLOCKS ||
                            tried_backup_jnl)
                                goto errout;
                        memset(&j_inode->i_ext2, 0, sizeof(struct ext2_inode));
                        memcpy(&j_inode->i_ext2.i_block[0], sb->s_jnl_blocks,
                               EXT2_N_BLOCKS*4);
                        j_inode->i_ext2.i_size_high = sb->s_jnl_blocks[15];
                        j_inode->i_ext2.i_size = sb->s_jnl_blocks[16];
                        j_inode->i_ext2.i_links_count = 1;
                        j_inode->i_ext2.i_mode = LINUX_S_IFREG | 0600;
                        e2fsck_use_inode_shortcuts(ctx, 1);
                        ctx->stashed_ino = j_inode->i_ino;
                        ctx->stashed_inode = &j_inode->i_ext2;
                        tried_backup_jnl++;
                }
                if (!j_inode->i_ext2.i_links_count ||
                    !LINUX_S_ISREG(j_inode->i_ext2.i_mode)) {
                        retval = EXT2_ET_NO_JOURNAL;
                        goto try_backup_journal;
                }
                if (EXT2_I_SIZE(&j_inode->i_ext2) / journal->j_blocksize <
                    JFS_MIN_JOURNAL_BLOCKS) {
                        retval = EXT2_ET_JOURNAL_TOO_SMALL;
                        goto try_backup_journal;
                }
                pb.last_block = -1;
                retval = ext2fs_block_iterate3(ctx->fs, j_inode->i_ino,
                                               BLOCK_FLAG_HOLE, 0,
                                               process_journal_block, &pb);
                if ((pb.last_block + 1) * ctx->fs->blocksize <
                    (int) EXT2_I_SIZE(&j_inode->i_ext2)) {
                        retval = EXT2_ET_JOURNAL_TOO_SMALL;
                        goto try_backup_journal;
                }
                if (tried_backup_jnl && !(ctx->options & E2F_OPT_READONLY)) {
                        retval = ext2fs_write_inode(ctx->fs, sb->s_journal_inum,
                                                    &j_inode->i_ext2);
                        if (retval)
                                goto errout;
                }

                journal->j_maxlen = EXT2_I_SIZE(&j_inode->i_ext2) /
                        journal->j_blocksize;

#ifdef USE_INODE_IO
                retval = ext2fs_inode_io_intern2(ctx->fs, sb->s_journal_inum,
                                                 &j_inode->i_ext2,
                                                 &journal_name);
                if (retval)
                        goto errout;

                io_ptr = inode_io_manager;
#else
                journal->j_inode = j_inode;
                ctx->journal_io = ctx->fs->io;
                if ((retval = (errcode_t) journal_bmap(journal, 0, &start)) != 0)
                        goto errout;
#endif
        } else {
                ext_journal = 1;
                if (!ctx->journal_name) {
                        char uuid[37];

                        uuid_unparse(sb->s_journal_uuid, uuid);
                        ctx->journal_name = blkid_get_devname(ctx->blkid,
                                                              "UUID", uuid);
                        if (!ctx->journal_name)
                                ctx->journal_name = blkid_devno_to_devname(sb->s_journal_dev);
                }
                journal_name = ctx->journal_name;

                if (!journal_name) {
                        fix_problem(ctx, PR_0_CANT_FIND_JOURNAL, &pctx);
                        retval = EXT2_ET_LOAD_EXT_JOURNAL;
                        goto errout;
                }

                jfs_debug(1, "Using journal file %s\n", journal_name);
                io_ptr = unix_io_manager;
        }

#if 0
        test_io_backing_manager = io_ptr;
        io_ptr = test_io_manager;
#endif
#ifndef USE_INODE_IO
        if (ext_journal)
#endif
        {
                int flags = IO_FLAG_RW;
                if (!(ctx->mount_flags & EXT2_MF_ISROOT &&
                      ctx->mount_flags & EXT2_MF_READONLY))
                        flags |= IO_FLAG_EXCLUSIVE;
                if ((ctx->mount_flags & EXT2_MF_READONLY) &&
                    (ctx->options & E2F_OPT_FORCE))
                        flags &= ~IO_FLAG_EXCLUSIVE;


                retval = io_ptr->open(journal_name, flags,
                                      &ctx->journal_io);
        }
        if (retval)
                goto errout;

        io_channel_set_blksize(ctx->journal_io, ctx->fs->blocksize);

        if (ext_journal) {
                blk64_t maxlen;

                start = ext2fs_journal_sb_start(ctx->fs->blocksize) - 1;
                bh = getblk(dev_journal, start, ctx->fs->blocksize);
                if (!bh) {
                        retval = EXT2_ET_NO_MEMORY;
                        goto errout;
                }
                ll_rw_block(READ, 1, &bh);
                if ((retval = bh->b_err) != 0) {
                        brelse(bh);
                        goto errout;
                }
                memcpy(&jsuper, start ? bh->b_data :  bh->b_data + SUPERBLOCK_OFFSET,
                       sizeof(jsuper));
#ifdef WORDS_BIGENDIAN
                if (jsuper.s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC))
                        ext2fs_swap_super(&jsuper);
#endif
                if (jsuper.s_magic != EXT2_SUPER_MAGIC ||
                    !ext2fs_has_feature_journal_dev(&jsuper)) {
                        fix_problem(ctx, PR_0_EXT_JOURNAL_BAD_SUPER, &pctx);
                        retval = EXT2_ET_LOAD_EXT_JOURNAL;
                        brelse(bh);
                        goto errout;
                }
                /* Make sure the journal UUID is correct */
                if (memcmp(jsuper.s_uuid, ctx->fs->super->s_journal_uuid,
                           sizeof(jsuper.s_uuid))) {
                        fix_problem(ctx, PR_0_JOURNAL_BAD_UUID, &pctx);
                        retval = EXT2_ET_LOAD_EXT_JOURNAL;
                        brelse(bh);
                        goto errout;
                }

                /* Check the superblock checksum */
                if (ext2fs_has_feature_metadata_csum(&jsuper)) {
                        struct struct_ext2_filsys fsx;
                        struct ext2_super_block superx;
                        void *p;

                        p = start ? bh->b_data : bh->b_data + SUPERBLOCK_OFFSET;
                        memcpy(&fsx, ctx->fs, sizeof(fsx));
                        memcpy(&superx, ctx->fs->super, sizeof(superx));
                        fsx.super = &superx;
                        ext2fs_set_feature_metadata_csum(fsx.super);
                        if (!ext2fs_superblock_csum_verify(&fsx, p) &&
                            fix_problem(ctx, PR_0_EXT_JOURNAL_SUPER_CSUM_INVALID,
                                        &pctx)) {
                                ext2fs_superblock_csum_set(&fsx, p);
                                mark_buffer_dirty(bh);
                        }
                }
                brelse(bh);

                maxlen = ext2fs_blocks_count(&jsuper);
                journal->j_maxlen = (maxlen < 1ULL << 32) ? maxlen : (1ULL << 32) - 1;
                start++;
        }

        if (!(bh = getblk(dev_journal, start, journal->j_blocksize))) {
                retval = EXT2_ET_NO_MEMORY;
                goto errout;
        }

        journal->j_sb_buffer = bh;
        journal->j_superblock = (journal_superblock_t *)bh->b_data;

#ifdef USE_INODE_IO
        if (j_inode)
                ext2fs_free_mem(&j_inode);
#endif

        *ret_journal = journal;
        e2fsck_use_inode_shortcuts(ctx, 0);
        return 0;

errout:
        e2fsck_use_inode_shortcuts(ctx, 0);
        if (dev_fs)
                ext2fs_free_mem(&dev_fs);
        if (j_inode)
                ext2fs_free_mem(&j_inode);
        if (journal)
                ext2fs_free_mem(&journal);
        return retval;
}

static errcode_t e2fsck_journal_fix_bad_inode(e2fsck_t ctx,
                                              struct problem_context *pctx)
{
        struct ext2_super_block *sb = ctx->fs->super;
        int recover = ext2fs_has_feature_journal_needs_recovery(ctx->fs->super);
        int has_journal = ext2fs_has_feature_journal(ctx->fs->super);

        if (has_journal || sb->s_journal_inum) {
                /* The journal inode is bogus, remove and force full fsck */
                pctx->ino = sb->s_journal_inum;
                if (fix_problem(ctx, PR_0_JOURNAL_BAD_INODE, pctx)) {
                        if (has_journal && sb->s_journal_inum)
                                printf("*** journal has been deleted ***\n\n");
                        ext2fs_clear_feature_journal(sb);
                        sb->s_journal_inum = 0;
                        memset(sb->s_jnl_blocks, 0, sizeof(sb->s_jnl_blocks));
                        ctx->flags |= E2F_FLAG_JOURNAL_INODE;
                        ctx->fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
                        e2fsck_clear_recover(ctx, 1);
                        return 0;
                }
                return EXT2_ET_CORRUPT_JOURNAL_SB;
        } else if (recover) {
                if (fix_problem(ctx, PR_0_JOURNAL_RECOVER_SET, pctx)) {
                        e2fsck_clear_recover(ctx, 1);
                        return 0;
                }
                return EXT2_ET_UNSUPP_FEATURE;
        }
        return 0;
}

#define V1_SB_SIZE      0x0024
static void clear_v2_journal_fields(journal_t *journal)
{
        e2fsck_t ctx = journal->j_dev->k_ctx;
        struct problem_context pctx;

        clear_problem_context(&pctx);

        if (!fix_problem(ctx, PR_0_CLEAR_V2_JOURNAL, &pctx))
                return;

        ctx->flags |= E2F_FLAG_PROBLEMS_FIXED;
        memset(((char *) journal->j_superblock) + V1_SB_SIZE, 0,
               ctx->fs->blocksize-V1_SB_SIZE);
        mark_buffer_dirty(journal->j_sb_buffer);
}


static errcode_t e2fsck_journal_load(journal_t *journal)
{
        e2fsck_t ctx = journal->j_dev->k_ctx;
        journal_superblock_t *jsb;
        struct buffer_head *jbh = journal->j_sb_buffer;
        struct problem_context pctx;

        clear_problem_context(&pctx);

        ll_rw_block(READ, 1, &jbh);
        if (jbh->b_err) {
                com_err(ctx->device_name, jbh->b_err, "%s",
                        _("reading journal superblock\n"));
                return jbh->b_err;
        }

        jsb = journal->j_superblock;
        /* If we don't even have JFS_MAGIC, we probably have a wrong inode */
        if (jsb->s_header.h_magic != htonl(JFS_MAGIC_NUMBER))
                return e2fsck_journal_fix_bad_inode(ctx, &pctx);

        switch (ntohl(jsb->s_header.h_blocktype)) {
        case JFS_SUPERBLOCK_V1:
                journal->j_format_version = 1;
                if (jsb->s_feature_compat ||
                    jsb->s_feature_incompat ||
                    jsb->s_feature_ro_compat ||
                    jsb->s_nr_users)
                        clear_v2_journal_fields(journal);
                break;

        case JFS_SUPERBLOCK_V2:
                journal->j_format_version = 2;
                if (ntohl(jsb->s_nr_users) > 1 &&
                    uuid_is_null(ctx->fs->super->s_journal_uuid))
                        clear_v2_journal_fields(journal);
                if (ntohl(jsb->s_nr_users) > 1) {
                        fix_problem(ctx, PR_0_JOURNAL_UNSUPP_MULTIFS, &pctx);
                        return EXT2_ET_JOURNAL_UNSUPP_VERSION;
                }
                break;

        /*
         * These should never appear in a journal super block, so if
         * they do, the journal is badly corrupted.
         */
        case JFS_DESCRIPTOR_BLOCK:
        case JFS_COMMIT_BLOCK:
        case JFS_REVOKE_BLOCK:
                return EXT2_ET_CORRUPT_JOURNAL_SB;

        /* If we don't understand the superblock major type, but there
         * is a magic number, then it is likely to be a new format we
         * just don't understand, so leave it alone. */
        default:
                return EXT2_ET_JOURNAL_UNSUPP_VERSION;
        }

        if (JFS_HAS_INCOMPAT_FEATURE(journal, ~JFS_KNOWN_INCOMPAT_FEATURES))
                return EXT2_ET_UNSUPP_FEATURE;

        if (JFS_HAS_RO_COMPAT_FEATURE(journal, ~JFS_KNOWN_ROCOMPAT_FEATURES))
                return EXT2_ET_RO_UNSUPP_FEATURE;

        /* Checksum v1-3 are mutually exclusive features. */
        if (jfs_has_feature_csum2(journal) && jfs_has_feature_csum3(journal))
                return EXT2_ET_CORRUPT_JOURNAL_SB;

        if (journal_has_csum_v2or3(journal) &&
            jfs_has_feature_checksum(journal))
                return EXT2_ET_CORRUPT_JOURNAL_SB;

        if (!e2fsck_journal_verify_csum_type(journal, jsb) ||
            !e2fsck_journal_sb_csum_verify(journal, jsb))
                return EXT2_ET_CORRUPT_JOURNAL_SB;

        if (journal_has_csum_v2or3(journal))
                journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
                                                   sizeof(jsb->s_uuid));

        /* We have now checked whether we know enough about the journal
         * format to be able to proceed safely, so any other checks that
         * fail we should attempt to recover from. */
        if (jsb->s_blocksize != htonl(journal->j_blocksize)) {
                com_err(ctx->program_name, EXT2_ET_CORRUPT_JOURNAL_SB,
                        _("%s: no valid journal superblock found\n"),
                        ctx->device_name);
                return EXT2_ET_CORRUPT_JOURNAL_SB;
        }

        if (ntohl(jsb->s_maxlen) < journal->j_maxlen)
                journal->j_maxlen = ntohl(jsb->s_maxlen);
        else if (ntohl(jsb->s_maxlen) > journal->j_maxlen) {
                com_err(ctx->program_name, EXT2_ET_CORRUPT_JOURNAL_SB,
                        _("%s: journal too short\n"),
                        ctx->device_name);
                return EXT2_ET_CORRUPT_JOURNAL_SB;
        }

        journal->j_tail_sequence = ntohl(jsb->s_sequence);
        journal->j_transaction_sequence = journal->j_tail_sequence;
        journal->j_tail = ntohl(jsb->s_start);
        journal->j_first = ntohl(jsb->s_first);
        journal->j_last = ntohl(jsb->s_maxlen);

        return 0;
}

static void e2fsck_journal_reset_super(e2fsck_t ctx, journal_superblock_t *jsb,
                                       journal_t *journal)
{
        char *p;
        union {
                uuid_t uuid;
                __u32 val[4];
        } u;
        __u32 new_seq = 0;
        int i;

        /* Leave a valid existing V1 superblock signature alone.
         * Anything unrecognisable we overwrite with a new V2
         * signature. */

        if (jsb->s_header.h_magic != htonl(JFS_MAGIC_NUMBER) ||
            jsb->s_header.h_blocktype != htonl(JFS_SUPERBLOCK_V1)) {
                jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
                jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
        }

        /* Zero out everything else beyond the superblock header */

        p = ((char *) jsb) + sizeof(journal_header_t);
        memset (p, 0, ctx->fs->blocksize-sizeof(journal_header_t));

        jsb->s_blocksize = htonl(ctx->fs->blocksize);
        jsb->s_maxlen = htonl(journal->j_maxlen);
        jsb->s_first = htonl(1);

        /* Initialize the journal sequence number so that there is "no"
         * chance we will find old "valid" transactions in the journal.
         * This avoids the need to zero the whole journal (slow to do,
         * and risky when we are just recovering the filesystem).
         */
        uuid_generate(u.uuid);
        for (i = 0; i < 4; i ++)
                new_seq ^= u.val[i];
        jsb->s_sequence = htonl(new_seq);
        e2fsck_journal_sb_csum_set(journal, jsb);

        mark_buffer_dirty(journal->j_sb_buffer);
        ll_rw_block(WRITE, 1, &journal->j_sb_buffer);
}

static errcode_t e2fsck_journal_fix_corrupt_super(e2fsck_t ctx,
                                                  journal_t *journal,
                                                  struct problem_context *pctx)
{
        struct ext2_super_block *sb = ctx->fs->super;
        int recover = ext2fs_has_feature_journal_needs_recovery(ctx->fs->super);

        if (ext2fs_has_feature_journal(sb)) {
                if (fix_problem(ctx, PR_0_JOURNAL_BAD_SUPER, pctx)) {
                        e2fsck_journal_reset_super(ctx, journal->j_superblock,
                                                   journal);
                        journal->j_transaction_sequence = 1;
                        e2fsck_clear_recover(ctx, recover);
                        return 0;
                }
                return EXT2_ET_CORRUPT_JOURNAL_SB;
        } else if (e2fsck_journal_fix_bad_inode(ctx, pctx))
                return EXT2_ET_CORRUPT_JOURNAL_SB;

        return 0;
}

static void e2fsck_journal_release(e2fsck_t ctx, journal_t *journal,
                                   int reset, int drop)
{
        journal_superblock_t *jsb;

        if (drop)
                mark_buffer_clean(journal->j_sb_buffer);
        else if (!(ctx->options & E2F_OPT_READONLY)) {
                jsb = journal->j_superblock;
                jsb->s_sequence = htonl(journal->j_tail_sequence);
                if (reset)
                        jsb->s_start = 0; /* this marks the journal as empty */
                e2fsck_journal_sb_csum_set(journal, jsb);
                mark_buffer_dirty(journal->j_sb_buffer);
        }
        brelse(journal->j_sb_buffer);

        if (ctx->journal_io) {
                if (ctx->fs && ctx->fs->io != ctx->journal_io)
                        io_channel_close(ctx->journal_io);
                ctx->journal_io = 0;
        }

#ifndef USE_INODE_IO
        if (journal->j_inode)
                ext2fs_free_mem(&journal->j_inode);
#endif
        if (journal->j_fs_dev)
                ext2fs_free_mem(&journal->j_fs_dev);
        ext2fs_free_mem(&journal);
}

/*
 * This function makes sure that the superblock fields regarding the
 * journal are consistent.
 */
errcode_t e2fsck_check_ext3_journal(e2fsck_t ctx)
{
        struct ext2_super_block *sb = ctx->fs->super;
        journal_t *journal;
        int recover = ext2fs_has_feature_journal_needs_recovery(ctx->fs->super);
        struct problem_context pctx;
        problem_t problem;
        int reset = 0, force_fsck = 0;
        errcode_t retval;

        /* If we don't have any journal features, don't do anything more */
        if (!ext2fs_has_feature_journal(sb) &&
            !recover && sb->s_journal_inum == 0 && sb->s_journal_dev == 0 &&
            uuid_is_null(sb->s_journal_uuid))
                return 0;

        clear_problem_context(&pctx);
        pctx.num = sb->s_journal_inum;

        retval = e2fsck_get_journal(ctx, &journal);
        if (retval) {
                if ((retval == EXT2_ET_BAD_INODE_NUM) ||
                    (retval == EXT2_ET_BAD_BLOCK_NUM) ||
                    (retval == EXT2_ET_JOURNAL_TOO_SMALL) ||
                    (retval == EXT2_ET_NO_JOURNAL))
                        return e2fsck_journal_fix_bad_inode(ctx, &pctx);
                return retval;
        }

        retval = e2fsck_journal_load(journal);
        if (retval) {
                if ((retval == EXT2_ET_CORRUPT_JOURNAL_SB) ||
                    ((retval == EXT2_ET_UNSUPP_FEATURE) &&
                    (!fix_problem(ctx, PR_0_JOURNAL_UNSUPP_INCOMPAT,
                                  &pctx))) ||
                    ((retval == EXT2_ET_RO_UNSUPP_FEATURE) &&
                    (!fix_problem(ctx, PR_0_JOURNAL_UNSUPP_ROCOMPAT,
                                  &pctx))) ||
                    ((retval == EXT2_ET_JOURNAL_UNSUPP_VERSION) &&
                    (!fix_problem(ctx, PR_0_JOURNAL_UNSUPP_VERSION, &pctx))))
                        retval = e2fsck_journal_fix_corrupt_super(ctx, journal,
                                                                  &pctx);
                e2fsck_journal_release(ctx, journal, 0, 1);
                return retval;
        }

        /*
         * We want to make the flags consistent here.  We will not leave with
         * needs_recovery set but has_journal clear.  We can't get in a loop
         * with -y, -n, or -p, only if a user isn't making up their mind.
         */
no_has_journal:
        if (!ext2fs_has_feature_journal(sb)) {
                recover = ext2fs_has_feature_journal_needs_recovery(sb);
                if (fix_problem(ctx, PR_0_JOURNAL_HAS_JOURNAL, &pctx)) {
                        if (recover &&
                            !fix_problem(ctx, PR_0_JOURNAL_RECOVER_SET, &pctx))
                                goto no_has_journal;
                        /*
                         * Need a full fsck if we are releasing a
                         * journal stored on a reserved inode.
                         */
                        force_fsck = recover ||
                                (sb->s_journal_inum < EXT2_FIRST_INODE(sb));
                        /* Clear all of the journal fields */
                        sb->s_journal_inum = 0;
                        sb->s_journal_dev = 0;
                        memset(sb->s_journal_uuid, 0,
                               sizeof(sb->s_journal_uuid));
                        e2fsck_clear_recover(ctx, force_fsck);
                } else if (!(ctx->options & E2F_OPT_READONLY)) {
                        ext2fs_set_feature_journal(sb);
                        ctx->fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
                        ext2fs_mark_super_dirty(ctx->fs);
                }
        }

        if (ext2fs_has_feature_journal(sb) &&
            !ext2fs_has_feature_journal_needs_recovery(sb) &&
            journal->j_superblock->s_start != 0) {
                /* Print status information */
                fix_problem(ctx, PR_0_JOURNAL_RECOVERY_CLEAR, &pctx);
                if (ctx->superblock)
                        problem = PR_0_JOURNAL_RUN_DEFAULT;
                else
                        problem = PR_0_JOURNAL_RUN;
                if (fix_problem(ctx, problem, &pctx)) {
                        ctx->options |= E2F_OPT_FORCE;
                        ext2fs_set_feature_journal_needs_recovery(sb);
                        ext2fs_mark_super_dirty(ctx->fs);
                } else if (fix_problem(ctx,
                                       PR_0_JOURNAL_RESET_JOURNAL, &pctx)) {
                        reset = 1;
                        sb->s_state &= ~EXT2_VALID_FS;
                        ext2fs_mark_super_dirty(ctx->fs);
                }
                /*
                 * If the user answers no to the above question, we
                 * ignore the fact that journal apparently has data;
                 * accidentally replaying over valid data would be far
                 * worse than skipping a questionable recovery.
                 *
                 * XXX should we abort with a fatal error here?  What
                 * will the ext3 kernel code do if a filesystem with
                 * !NEEDS_RECOVERY but with a non-zero
                 * journal->j_superblock->s_start is mounted?
                 */
        }

        /*
         * If we don't need to do replay the journal, check to see if
         * the journal's errno is set; if so, we need to mark the file
         * system as being corrupt and clear the journal's s_errno.
         */
        if (!ext2fs_has_feature_journal_needs_recovery(sb) &&
            journal->j_superblock->s_errno) {
                ctx->fs->super->s_state |= EXT2_ERROR_FS;
                ext2fs_mark_super_dirty(ctx->fs);
                journal->j_superblock->s_errno = 0;
                e2fsck_journal_sb_csum_set(journal, journal->j_superblock);
                mark_buffer_dirty(journal->j_sb_buffer);
        }

        e2fsck_journal_release(ctx, journal, reset, 0);
        return retval;
}

static errcode_t recover_ext3_journal(e2fsck_t ctx)
{
        struct problem_context  pctx;
        journal_t *journal;
        errcode_t retval;

        clear_problem_context(&pctx);

        journal_init_revoke_caches();
        retval = e2fsck_get_journal(ctx, &journal);
        if (retval)
                return retval;

        retval = e2fsck_journal_load(journal);
        if (retval)
                goto errout;

        retval = journal_init_revoke(journal, 1024);
        if (retval)
                goto errout;

        retval = -journal_recover(journal);
        if (retval)
                goto errout;

        if (journal->j_failed_commit) {
                pctx.ino = journal->j_failed_commit;
                fix_problem(ctx, PR_0_JNL_TXN_CORRUPT, &pctx);
                journal->j_superblock->s_errno = -EINVAL;
                mark_buffer_dirty(journal->j_sb_buffer);
        }

        journal->j_tail_sequence = journal->j_transaction_sequence;

errout:
        journal_destroy_revoke(journal);
        journal_destroy_revoke_caches();
        e2fsck_journal_release(ctx, journal, 1, 0);
        return retval;
}

errcode_t e2fsck_run_ext3_journal(e2fsck_t ctx)
{
        io_manager io_ptr = ctx->fs->io->manager;
        int blocksize = ctx->fs->blocksize;
        errcode_t       retval, recover_retval;
        io_stats        stats = 0;
        unsigned long long kbytes_written = 0;

        printf(_("%s: recovering journal\n"), ctx->device_name);
        if (ctx->options & E2F_OPT_READONLY) {
                printf(_("%s: won't do journal recovery while read-only\n"),
                       ctx->device_name);
                return EXT2_ET_FILE_RO;
        }

        if (ctx->fs->flags & EXT2_FLAG_DIRTY)
                ext2fs_flush(ctx->fs);  /* Force out any modifications */

        recover_retval = recover_ext3_journal(ctx);

        /*
         * Reload the filesystem context to get up-to-date data from disk
         * because journal recovery will change the filesystem under us.
         */
        if (ctx->fs->super->s_kbytes_written &&
            ctx->fs->io->manager->get_stats)
                ctx->fs->io->manager->get_stats(ctx->fs->io, &stats);
        if (stats && stats->bytes_written)
                kbytes_written = stats->bytes_written >> 10;

        ext2fs_mmp_stop(ctx->fs);
        ext2fs_free(ctx->fs);
        retval = ext2fs_open(ctx->filesystem_name, ctx->openfs_flags,
                             ctx->superblock, blocksize, io_ptr,
                             &ctx->fs);
        if (retval) {
                com_err(ctx->program_name, retval,
                        _("while trying to re-open %s"),
                        ctx->device_name);
                fatal_error(ctx, 0);
        }
        ctx->fs->priv_data = ctx;
        ctx->fs->now = ctx->now;
        ctx->fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
        ctx->fs->super->s_kbytes_written += kbytes_written;

        /* Set the superblock flags */
        e2fsck_clear_recover(ctx, recover_retval != 0);

        /*
         * Do one last sanity check, and propagate journal->s_errno to
         * the EXT2_ERROR_FS flag in the fs superblock if needed.
         */
        retval = e2fsck_check_ext3_journal(ctx);
        return retval ? retval : recover_retval;
}

/*
 * This function will move the journal inode from a visible file in
 * the filesystem directory hierarchy to the reserved inode if necessary.
 */
static const char * const journal_names[] = {
        ".journal", "journal", ".journal.dat", "journal.dat", 0 };

void e2fsck_move_ext3_journal(e2fsck_t ctx)
{
        struct ext2_super_block *sb = ctx->fs->super;
        struct problem_context  pctx;
        struct ext2_inode       inode;
        ext2_filsys             fs = ctx->fs;
        ext2_ino_t              ino;
        errcode_t               retval;
        const char * const *    cpp;
        dgrp_t                  group;
        int                     mount_flags;

        clear_problem_context(&pctx);

        /*
         * If the filesystem is opened read-only, or there is no
         * journal, then do nothing.
         */
        if ((ctx->options & E2F_OPT_READONLY) ||
            (sb->s_journal_inum == 0) ||
            !ext2fs_has_feature_journal(sb))
                return;

        /*
         * Read in the journal inode
         */
        if (ext2fs_read_inode(fs, sb->s_journal_inum, &inode) != 0)
                return;

        /*
         * If it's necessary to backup the journal inode, do so.
         */
        if ((sb->s_jnl_backup_type == 0) ||
            ((sb->s_jnl_backup_type == EXT3_JNL_BACKUP_BLOCKS) &&
             memcmp(inode.i_block, sb->s_jnl_blocks, EXT2_N_BLOCKS*4))) {
                if (fix_problem(ctx, PR_0_BACKUP_JNL, &pctx)) {
                        memcpy(sb->s_jnl_blocks, inode.i_block,
                               EXT2_N_BLOCKS*4);
                        sb->s_jnl_blocks[15] = inode.i_size_high;
                        sb->s_jnl_blocks[16] = inode.i_size;
                        sb->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
                        ext2fs_mark_super_dirty(fs);
                        fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
                }
        }

        /*
         * If the journal is already the hidden inode, then do nothing
         */
        if (sb->s_journal_inum == EXT2_JOURNAL_INO)
                return;

        /*
         * The journal inode had better have only one link and not be readable.
         */
        if (inode.i_links_count != 1)
                return;

        /*
         * If the filesystem is mounted, or we can't tell whether
         * or not it's mounted, do nothing.
         */
        retval = ext2fs_check_if_mounted(ctx->filesystem_name, &mount_flags);
        if (retval || (mount_flags & EXT2_MF_MOUNTED))
                return;

        /*
         * If we can't find the name of the journal inode, then do
         * nothing.
         */
        for (cpp = journal_names; *cpp; cpp++) {
                retval = ext2fs_lookup(fs, EXT2_ROOT_INO, *cpp,
                                       strlen(*cpp), 0, &ino);
                if ((retval == 0) && (ino == sb->s_journal_inum))
                        break;
        }
        if (*cpp == 0)
                return;

        /* We need the inode bitmap to be loaded */
        retval = ext2fs_read_bitmaps(fs);
        if (retval)
                return;

        pctx.str = *cpp;
        if (!fix_problem(ctx, PR_0_MOVE_JOURNAL, &pctx))
                return;

        /*
         * OK, we've done all the checks, let's actually move the
         * journal inode.  Errors at this point mean we need to force
         * an ext2 filesystem check.
         */
        if ((retval = ext2fs_unlink(fs, EXT2_ROOT_INO, *cpp, ino, 0)) != 0)
                goto err_out;
        if ((retval = ext2fs_write_inode(fs, EXT2_JOURNAL_INO, &inode)) != 0)
                goto err_out;
        sb->s_journal_inum = EXT2_JOURNAL_INO;
        ext2fs_mark_super_dirty(fs);
        fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
        inode.i_links_count = 0;
        inode.i_dtime = ctx->now;
        if ((retval = ext2fs_write_inode(fs, ino, &inode)) != 0)
                goto err_out;

        group = ext2fs_group_of_ino(fs, ino);
        ext2fs_unmark_inode_bitmap2(fs->inode_map, ino);
        ext2fs_mark_ib_dirty(fs);
        ext2fs_bg_free_inodes_count_set(fs, group, ext2fs_bg_free_inodes_count(fs, group) + 1);
        ext2fs_group_desc_csum_set(fs, group);
        fs->super->s_free_inodes_count++;
        return;

err_out:
        pctx.errcode = retval;
        fix_problem(ctx, PR_0_ERR_MOVE_JOURNAL, &pctx);
        fs->super->s_state &= ~EXT2_VALID_FS;
        ext2fs_mark_super_dirty(fs);
        return;
}

/*
 * This function makes sure the superblock hint for the external
 * journal is correct.
 */
int e2fsck_fix_ext3_journal_hint(e2fsck_t ctx)
{
        struct ext2_super_block *sb = ctx->fs->super;
        struct problem_context pctx;
        char uuid[37], *journal_name;
        struct stat st;

        if (!ext2fs_has_feature_journal(sb) ||
            uuid_is_null(sb->s_journal_uuid))
                return 0;

        uuid_unparse(sb->s_journal_uuid, uuid);
        journal_name = blkid_get_devname(ctx->blkid, "UUID", uuid);
        if (!journal_name)
                return 0;

        if (stat(journal_name, &st) < 0) {
                free(journal_name);
                return 0;
        }

        if (st.st_rdev != sb->s_journal_dev) {
                clear_problem_context(&pctx);
                pctx.num = st.st_rdev;
                if (fix_problem(ctx, PR_0_EXTERNAL_JOURNAL_HINT, &pctx)) {
                        sb->s_journal_dev = st.st_rdev;
                        ext2fs_mark_super_dirty(ctx->fs);
                }
        }

        free(journal_name);
        return 0;
}