Merge branch 'maint' into next

[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"

static int bh_count = 0;

/*
 * 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 (!jbd2_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 (!jbd2_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 (!jbd2_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 jbd2_journal_bmap(journal_t *journal, unsigned long 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, (blk64_t) block,
                             0, &pblk);
        *phys = pblk;
        return -1 * ((int) retval);
#endif
}

struct buffer_head *getblk(kdev_t kdev, unsigned long long 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;

        if (journal_enable_debug >= 3)
                bh_count++;
        jfs_debug(4, "getblk for block %llu (%d bytes)(total %d)\n",
                  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 op_flags EXT2FS_ATTR((unused)), int nr,
                 struct buffer_head *bhp[])
{
        errcode_t retval;
        struct buffer_head *bh;

        for (; nr > 0; --nr) {
                bh = *bhp++;
                if (rw == REQ_OP_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 == REQ_OP_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 == REQ_OP_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(REQ_OP_WRITE, 0, 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(REQ_OP_READ, 0, 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 int ext4_fc_replay_scan(journal_t *j, struct buffer_head *bh,
                                int off, tid_t expected_tid)
{
        e2fsck_t ctx = j->j_fs_dev->k_ctx;
        struct e2fsck_fc_replay_state *state;
        int ret = JBD2_FC_REPLAY_CONTINUE;
        struct ext4_fc_add_range ext;
        struct ext4_fc_tl tl;
        struct ext4_fc_tail tail;
        __u8 *start, *cur, *end, *val;
        struct ext4_fc_head head;
        struct ext2fs_extent ext2fs_ex = {0};

        state = &ctx->fc_replay_state;

        start = (__u8 *)bh->b_data;
        end = (__u8 *)bh->b_data + j->j_blocksize - 1;

        jbd_debug(1, "Scan phase starting, expected %d", expected_tid);
        if (state->fc_replay_expected_off == 0) {
                memset(state, 0, sizeof(*state));
                /* Check if we can stop early */
                if (le16_to_cpu(((struct ext4_fc_tl *)start)->fc_tag)
                        != EXT4_FC_TAG_HEAD) {
                        jbd_debug(1, "Ending early!, not a head tag");
                        return 0;
                }
        }

        if (off != state->fc_replay_expected_off) {
                ret = -EFSCORRUPTED;
                goto out_err;
        }

        state->fc_replay_expected_off++;
        for (cur = start; cur < end; cur = cur + le16_to_cpu(tl.fc_len) + sizeof(tl)) {
                memcpy(&tl, cur, sizeof(tl));
                val = cur + sizeof(tl);

                jbd_debug(3, "Scan phase, tag:%s, blk %lld\n",
                          tag2str(le16_to_cpu(tl.fc_tag)), bh->b_blocknr);
                switch (le16_to_cpu(tl.fc_tag)) {
                case EXT4_FC_TAG_ADD_RANGE:
                        memcpy(&ext, val, sizeof(ext));
                        ret = ext2fs_decode_extent(&ext2fs_ex,
                                                   (void *)&ext.fc_ex,
                                                   sizeof(ext.fc_ex));
                        if (ret)
                                ret = JBD2_FC_REPLAY_STOP;
                        else
                                ret = JBD2_FC_REPLAY_CONTINUE;
                        /* fallthrough */
                case EXT4_FC_TAG_DEL_RANGE:
                case EXT4_FC_TAG_LINK:
                case EXT4_FC_TAG_UNLINK:
                case EXT4_FC_TAG_CREAT:
                case EXT4_FC_TAG_INODE:
                case EXT4_FC_TAG_PAD:
                        state->fc_cur_tag++;
                        state->fc_crc = jbd2_chksum(j, state->fc_crc, cur,
                                        sizeof(tl) + ext4_fc_tag_len(&tl));
                        break;
                case EXT4_FC_TAG_TAIL:
                        state->fc_cur_tag++;
                        memcpy(&tail, val, sizeof(tail));
                        state->fc_crc = jbd2_chksum(j, state->fc_crc, cur,
                                                sizeof(tl) +
                                                offsetof(struct ext4_fc_tail,
                                                fc_crc));
                        jbd_debug(1, "tail tid %d, expected %d\n",
                                  le32_to_cpu(tail.fc_tid), expected_tid);
                        if (le32_to_cpu(tail.fc_tid) == expected_tid &&
                            le32_to_cpu(tail.fc_crc) == state->fc_crc) {
                                state->fc_replay_num_tags = state->fc_cur_tag;
                        } else {
                                ret = state->fc_replay_num_tags ?
                                        JBD2_FC_REPLAY_STOP : -EFSBADCRC;
                        }
                        state->fc_crc = 0;
                        break;
                case EXT4_FC_TAG_HEAD:
                        memcpy(&head, val, sizeof(head));
                        if (le32_to_cpu(head.fc_features) &
                            ~EXT4_FC_SUPPORTED_FEATURES) {
                                ret = -EOPNOTSUPP;
                                break;
                        }
                        if (le32_to_cpu(head.fc_tid) != expected_tid) {
                                ret = -EINVAL;
                                break;
                        }
                        state->fc_cur_tag++;
                        state->fc_crc = jbd2_chksum(j, state->fc_crc, cur,
                                        sizeof(tl) + ext4_fc_tag_len(&tl));
                        break;
                default:
                        ret = state->fc_replay_num_tags ?
                                JBD2_FC_REPLAY_STOP : -ECANCELED;
                }
                if (ret < 0 || ret == JBD2_FC_REPLAY_STOP)
                        break;
        }

out_err:
        return ret;
}

static int __errcode_to_errno(errcode_t err, const char *func, int line)
{
        if (err == 0)
                return 0;
        fprintf(stderr, "Error \"%s\" encountered in function %s at line %d\n",
                error_message(err), func, line);
        if (err <= 256)
                return -err;
        return -EFAULT;
}

#define errcode_to_errno(err)   __errcode_to_errno(err, __func__, __LINE__)

#define ex_end(__ex) ((__ex)->e_lblk + (__ex)->e_len - 1)
#define ex_pend(__ex) ((__ex)->e_pblk + (__ex)->e_len - 1)

static int make_room(struct extent_list *list, int i)
{
        int ret;

        if (list->count == list->size) {
                unsigned int new_size = (list->size + 341) *
                                        sizeof(struct ext2fs_extent);
                ret = errcode_to_errno(ext2fs_resize_mem(0, new_size, &list->extents));
                if (ret)
                        return ret;
                list->size += 341;
        }

        memmove(&list->extents[i + 1], &list->extents[i],
                        sizeof(list->extents[0]) * (list->count - i));
        list->count++;
        return 0;
}

static int ex_compar(const void *arg1, const void *arg2)
{
        const struct ext2fs_extent *ex1 = (const struct ext2fs_extent *)arg1;
        const struct ext2fs_extent *ex2 = (const struct ext2fs_extent *)arg2;

        if (ex1->e_lblk < ex2->e_lblk)
                return -1;
        if (ex1->e_lblk > ex2->e_lblk)
                return 1;
        return ex1->e_len - ex2->e_len;
}

static int ex_len_compar(const void *arg1, const void *arg2)
{
        const struct ext2fs_extent *ex1 = (const struct ext2fs_extent *)arg1;
        const struct ext2fs_extent *ex2 = (const struct ext2fs_extent *)arg2;

        if (ex1->e_len < ex2->e_len)
                return 1;

        if (ex1->e_lblk > ex2->e_lblk)
                return -1;

        return 0;
}

static void ex_sort_and_merge(struct extent_list *list)
{
        unsigned int i, j;

        if (list->count < 2)
                return;

        /*
         * Reverse sort by length, that way we strip off all the 0 length
         * extents
         */
        qsort(list->extents, list->count, sizeof(struct ext2fs_extent),
                ex_len_compar);

        for (i = 0; i < list->count; i++) {
                if (list->extents[i].e_len == 0) {
                        list->count = i;
                        break;
                }
        }

        if (list->count == 0)
                return;

        /* Now sort by logical offset */
        qsort(list->extents, list->count, sizeof(list->extents[0]),
                ex_compar);

        /* Merge adjacent extents if they are logically and physically contiguous */
        i = 0;
        while (i < list->count - 1) {
                if (ex_end(&list->extents[i]) + 1 != list->extents[i + 1].e_lblk ||
                        ex_pend(&list->extents[i]) + 1 != list->extents[i + 1].e_pblk ||
                        (list->extents[i].e_flags & EXT2_EXTENT_FLAGS_UNINIT) !=
                                (list->extents[i + 1].e_flags & EXT2_EXTENT_FLAGS_UNINIT)) {
                        i++;
                        continue;
                }

                list->extents[i].e_len += list->extents[i + 1].e_len;
                for (j = i + 1; j < list->count - 1; j++)
                        list->extents[j] = list->extents[j + 1];
                list->count--;
        }
}

/* must free blocks that are released */
static int ext4_modify_extent_list(e2fsck_t ctx, struct extent_list *list,
                                        struct ext2fs_extent *ex, int del)
{
        int ret, offset;
        unsigned int i;
        struct ext2fs_extent add_ex = *ex;

        /* First let's create a hole from ex->e_lblk of length ex->e_len */
        for (i = 0; i < list->count; i++) {
                if (ex_end(&list->extents[i]) < add_ex.e_lblk)
                        continue;

                /* Case 1: No overlap */
                if (list->extents[i].e_lblk > ex_end(&add_ex))
                        break;
                /*
                 * Unmark all the blocks in bb now. All the blocks get marked
                 * before we exit this function.
                 */
                ext2fs_unmark_block_bitmap_range2(ctx->fs->block_map,
                        list->extents[i].e_pblk, list->extents[i].e_len);
                /* Case 2: Split */
                if (list->extents[i].e_lblk < add_ex.e_lblk &&
                        ex_end(&list->extents[i]) > ex_end(&add_ex)) {
                        ret = make_room(list, i + 1);
                        if (ret)
                                return ret;
                        list->extents[i + 1] = list->extents[i];
                        offset = ex_end(&add_ex) + 1 - list->extents[i].e_lblk;
                        list->extents[i + 1].e_lblk += offset;
                        list->extents[i + 1].e_pblk += offset;
                        list->extents[i + 1].e_len -= offset;
                        list->extents[i].e_len =
                                add_ex.e_lblk - list->extents[i].e_lblk;
                        break;
                }

                /* Case 3: Exact overlap */
                if (add_ex.e_lblk <= list->extents[i].e_lblk  &&
                        ex_end(&list->extents[i]) <= ex_end(&add_ex)) {

                        list->extents[i].e_len = 0;
                        continue;
                }

                /* Case 4: Partial overlap */
                if (ex_end(&list->extents[i]) > ex_end(&add_ex)) {
                        offset = ex_end(&add_ex) + 1 - list->extents[i].e_lblk;
                        list->extents[i].e_lblk += offset;
                        list->extents[i].e_pblk += offset;
                        list->extents[i].e_len -= offset;
                        break;
                }

                if (ex_end(&add_ex) >= ex_end(&list->extents[i]))
                        list->extents[i].e_len =
                                add_ex.e_lblk > list->extents[i].e_lblk ?
                                add_ex.e_lblk - list->extents[i].e_lblk : 0;
        }

        if (add_ex.e_len && !del) {
                make_room(list, list->count);
                list->extents[list->count - 1] = add_ex;
        }

        ex_sort_and_merge(list);

        /* Mark all occupied blocks allocated */
        for (i = 0; i < list->count; i++)
                ext2fs_mark_block_bitmap_range2(ctx->fs->block_map,
                        list->extents[i].e_pblk, list->extents[i].e_len);
        ext2fs_mark_bb_dirty(ctx->fs);

        return 0;
}

static int ext4_add_extent_to_list(e2fsck_t ctx, struct extent_list *list,
                                        struct ext2fs_extent *ex)
{
        return ext4_modify_extent_list(ctx, list, ex, 0 /* add */);
}

static int ext4_del_extent_from_list(e2fsck_t ctx, struct extent_list *list,
                                        struct ext2fs_extent *ex)
{
        return ext4_modify_extent_list(ctx, list, ex, 1 /* delete */);
}

static int ext4_fc_read_extents(e2fsck_t ctx, ext2_ino_t ino)
{
        struct extent_list *extent_list = &ctx->fc_replay_state.fc_extent_list;

        if (extent_list->ino == ino)
                return 0;

        extent_list->ino = ino;
        return errcode_to_errno(e2fsck_read_extents(ctx, extent_list));
}

/*
 * Flush extents in replay state on disk. @ino is the inode that is going
 * to be processed next. So, we hold back flushing of the extent list
 * if the next inode that's going to be processed is same as the one with
 * cached extents in our replay state. That allows us to gather multiple extents
 * for the inode so that we can flush all of them at once and it also saves us
 * from continuously growing and shrinking the extent tree.
 */
static void ext4_fc_flush_extents(e2fsck_t ctx, ext2_ino_t ino)
{
        struct extent_list *extent_list = &ctx->fc_replay_state.fc_extent_list;

        if (extent_list->ino == ino || extent_list->ino == 0)
                return;
        e2fsck_rewrite_extent_tree(ctx, extent_list);
        ext2fs_free_mem(&extent_list->extents);
        memset(extent_list, 0, sizeof(*extent_list));
}

/* Helper struct for dentry replay routines */
struct dentry_info_args {
        ext2_ino_t      parent_ino;
        ext2_ino_t      ino;
        int             dname_len;
        char            *dname;
};

static inline int tl_to_darg(struct dentry_info_args *darg,
                             struct  ext4_fc_tl *tl, __u8 *val)
{
        struct ext4_fc_dentry_info fcd;

        memcpy(&fcd, val, sizeof(fcd));

        darg->parent_ino = le32_to_cpu(fcd.fc_parent_ino);
        darg->ino = le32_to_cpu(fcd.fc_ino);
        darg->dname_len = ext4_fc_tag_len(tl) -
                        sizeof(struct ext4_fc_dentry_info);
        darg->dname = malloc(darg->dname_len + 1);
        if (!darg->dname)
                return -ENOMEM;
        memcpy(darg->dname,
               val + sizeof(struct ext4_fc_dentry_info),
               darg->dname_len);
        darg->dname[darg->dname_len] = 0;
        jbd_debug(1, "%s: %s, ino %u, parent %u\n",
                  le16_to_cpu(tl->fc_tag) == EXT4_FC_TAG_CREAT ? "create" :
                  (le16_to_cpu(tl->fc_tag) == EXT4_FC_TAG_LINK ? "link" :
                   (le16_to_cpu(tl->fc_tag) == EXT4_FC_TAG_UNLINK ? "unlink" :
                    "error")), darg->dname, darg->ino, darg->parent_ino);
        return 0;
}

static int ext4_fc_handle_unlink(e2fsck_t ctx, struct ext4_fc_tl *tl, __u8 *val)
{
        struct dentry_info_args darg;
        int ret;

        ret = tl_to_darg(&darg, tl, val);
        if (ret)
                return ret;
        ext4_fc_flush_extents(ctx, darg.ino);
        ret = errcode_to_errno(ext2fs_unlink(ctx->fs, darg.parent_ino,
                                             darg.dname, darg.ino, 0));
        /* It's okay if the above call fails */
        free(darg.dname);

        return ret;
}

static int ext4_fc_handle_link_and_create(e2fsck_t ctx, struct ext4_fc_tl *tl, __u8 *val)
{
        struct dentry_info_args darg;
        ext2_filsys fs = ctx->fs;
        struct ext2_inode_large inode_large;
        int ret, filetype, mode;

        ret = tl_to_darg(&darg, tl, val);
        if (ret)
                return ret;
        ext4_fc_flush_extents(ctx, 0);
        ret = errcode_to_errno(ext2fs_read_inode(fs, darg.ino,
                                                 (struct ext2_inode *)&inode_large));
        if (ret)
                goto out;

        mode = inode_large.i_mode;

        if (LINUX_S_ISREG(mode))
                filetype = EXT2_FT_REG_FILE;
        else if (LINUX_S_ISDIR(mode))
                filetype = EXT2_FT_DIR;
        else if (LINUX_S_ISCHR(mode))
                filetype = EXT2_FT_CHRDEV;
        else if (LINUX_S_ISBLK(mode))
                filetype = EXT2_FT_BLKDEV;
        else if (LINUX_S_ISLNK(mode))
                return EXT2_FT_SYMLINK;
        else if (LINUX_S_ISFIFO(mode))
                filetype = EXT2_FT_FIFO;
        else if (LINUX_S_ISSOCK(mode))
                filetype = EXT2_FT_SOCK;
        else {
                ret = -EINVAL;
                goto out;
        }

        /*
         * Forcefully unlink if the same name is present and ignore the error
         * if any, since this dirent might not exist
         */
        ext2fs_unlink(fs, darg.parent_ino, darg.dname, darg.ino,
                        EXT2FS_UNLINK_FORCE);

        ret = errcode_to_errno(
                       ext2fs_link(fs, darg.parent_ino, darg.dname, darg.ino,
                                   filetype));
out:
        free(darg.dname);
        return ret;

}

/* This function fixes the i_blocks field in the replayed indoe */
static void ext4_fc_replay_fixup_iblocks(struct ext2_inode_large *ondisk_inode,
        struct ext2_inode_large *fc_inode)
{
        if (ondisk_inode->i_flags & EXT4_EXTENTS_FL) {
                struct ext3_extent_header *eh;

                eh = (struct ext3_extent_header *)(&ondisk_inode->i_block[0]);
                if (le16_to_cpu(eh->eh_magic) != EXT3_EXT_MAGIC) {
                        memset(eh, 0, sizeof(*eh));
                        eh->eh_magic = cpu_to_le16(EXT3_EXT_MAGIC);
                        eh->eh_max = cpu_to_le16(
                                (sizeof(ondisk_inode->i_block) -
                                        sizeof(struct ext3_extent_header)) /
                                sizeof(struct ext3_extent));
                }
        } else if (ondisk_inode->i_flags & EXT4_INLINE_DATA_FL) {
                memcpy(ondisk_inode->i_block, fc_inode->i_block,
                        sizeof(fc_inode->i_block));
        }
}

static int ext4_fc_handle_inode(e2fsck_t ctx, __u8 *val)
{
        int ino, inode_len = EXT2_GOOD_OLD_INODE_SIZE;
        struct ext2_inode_large *inode = NULL, *fc_inode = NULL;
        __le32 fc_ino;
        __u8 *fc_raw_inode;
        errcode_t err;
        blk64_t blks;

        memcpy(&fc_ino, val, sizeof(fc_ino));
        fc_raw_inode = val + sizeof(fc_ino);
        ino = le32_to_cpu(fc_ino);

        if (EXT2_INODE_SIZE(ctx->fs->super) > EXT2_GOOD_OLD_INODE_SIZE) {
                __u16 extra_isize = ext2fs_le16_to_cpu(
                        ((struct ext2_inode_large *)fc_raw_inode)->i_extra_isize);

                if ((extra_isize < (sizeof(inode->i_extra_isize) +
                                    sizeof(inode->i_checksum_hi))) ||
                    (extra_isize > (EXT2_INODE_SIZE(ctx->fs->super) -
                                    EXT2_GOOD_OLD_INODE_SIZE))) {
                        err = EFSCORRUPTED;
                        goto out;
                }
                inode_len += extra_isize;
        }
        err = ext2fs_get_mem(inode_len, &inode);
        if (err)
                goto out;
        err = ext2fs_get_mem(inode_len, &fc_inode);
        if (err)
                goto out;
        ext4_fc_flush_extents(ctx, ino);

        err = ext2fs_read_inode_full(ctx->fs, ino, (struct ext2_inode *)inode,
                                        inode_len);
        if (err)
                goto out;
        memcpy(fc_inode, fc_raw_inode, inode_len);
#ifdef WORDS_BIGENDIAN
        ext2fs_swap_inode_full(ctx->fs, fc_inode, fc_inode, 0, inode_len);
#endif
        memcpy(inode, fc_inode, offsetof(struct ext2_inode_large, i_block));
        memcpy(&inode->i_generation, &fc_inode->i_generation,
                inode_len - offsetof(struct ext2_inode_large, i_generation));
        ext4_fc_replay_fixup_iblocks(inode, fc_inode);
        err = ext2fs_count_blocks(ctx->fs, ino, EXT2_INODE(inode), &blks);
        if (err)
                goto out;
        ext2fs_iblk_set(ctx->fs, EXT2_INODE(inode), blks);
        ext2fs_inode_csum_set(ctx->fs, ino, inode);

        err = ext2fs_write_inode_full(ctx->fs, ino, (struct ext2_inode *)inode,
                                        inode_len);
        if (err)
                goto out;
        if (inode->i_links_count)
                ext2fs_mark_inode_bitmap2(ctx->fs->inode_map, ino);
        else
                ext2fs_unmark_inode_bitmap2(ctx->fs->inode_map, ino);
        ext2fs_mark_ib_dirty(ctx->fs);

out:
        ext2fs_free_mem(&inode);
        ext2fs_free_mem(&fc_inode);
        return errcode_to_errno(err);
}

/*
 * Handle add extent replay tag.
 */
static int ext4_fc_handle_add_extent(e2fsck_t ctx, __u8 *val)
{
        struct ext2fs_extent extent;
        struct ext4_fc_add_range add_range;
        ext2_ino_t ino;
        int ret = 0;

        memcpy(&add_range, val, sizeof(add_range));
        ino = le32_to_cpu(add_range.fc_ino);
        ext4_fc_flush_extents(ctx, ino);

        ret = ext4_fc_read_extents(ctx, ino);
        if (ret)
                return ret;
        memset(&extent, 0, sizeof(extent));
        ret = errcode_to_errno(ext2fs_decode_extent(
                        &extent, (void *)add_range.fc_ex,
                        sizeof(add_range.fc_ex)));
        if (ret)
                return ret;
        return ext4_add_extent_to_list(ctx,
                &ctx->fc_replay_state.fc_extent_list, &extent);
}

/*
 * Handle delete logical range replay tag.
 */
static int ext4_fc_handle_del_range(e2fsck_t ctx, __u8 *val)
{
        struct ext2fs_extent extent;
        struct ext4_fc_del_range del_range;
        int ret, ino;

        memcpy(&del_range, val, sizeof(del_range));
        ino = le32_to_cpu(del_range.fc_ino);
        ext4_fc_flush_extents(ctx, ino);

        memset(&extent, 0, sizeof(extent));
        extent.e_lblk = le32_to_cpu(del_range.fc_lblk);
        extent.e_len = le32_to_cpu(del_range.fc_len);
        ret = ext4_fc_read_extents(ctx, ino);
        if (ret)
                return ret;
        return ext4_del_extent_from_list(ctx,
                &ctx->fc_replay_state.fc_extent_list, &extent);
}

/*
 * Main recovery path entry point. This function returns JBD2_FC_REPLAY_CONTINUE
 * to indicate that it is expecting more fast commit blocks. It returns
 * JBD2_FC_REPLAY_STOP to indicate that replay is done.
 */
static int ext4_fc_replay(journal_t *journal, struct buffer_head *bh,
                                enum passtype pass, int off, tid_t expected_tid)
{
        e2fsck_t ctx = journal->j_fs_dev->k_ctx;
        struct e2fsck_fc_replay_state *state = &ctx->fc_replay_state;
        int ret = JBD2_FC_REPLAY_CONTINUE;
        struct ext4_fc_tl tl;
        __u8 *start, *end, *cur, *val;

        if (pass == PASS_SCAN) {
                state->fc_current_pass = PASS_SCAN;
                return ext4_fc_replay_scan(journal, bh, off, expected_tid);
        }

        if (state->fc_replay_num_tags == 0)
                goto replay_done;

        if (state->fc_current_pass != pass) {
                /* Starting replay phase */
                state->fc_current_pass = pass;
                /* We will reset checksums */
                ctx->fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
                ret = errcode_to_errno(ext2fs_read_bitmaps(ctx->fs));
                if (ret) {
                        jbd_debug(1, "Error %d while reading bitmaps\n", ret);
                        return ret;
                }
                state->fc_super_state = ctx->fs->super->s_state;
                /*
                 * Mark the file system to indicate it contains errors. That's
                 * because the updates performed by fast commit replay code are
                 * not atomic and may result in inconsistent file system if it
                 * crashes before the replay is complete.
                 */
                ctx->fs->super->s_state |= EXT2_ERROR_FS;
                ctx->fs->super->s_state |= EXT4_FC_REPLAY;
                ext2fs_mark_super_dirty(ctx->fs);
                ext2fs_flush(ctx->fs);
        }

        start = (__u8 *)bh->b_data;
        end = (__u8 *)bh->b_data + journal->j_blocksize - 1;

        for (cur = start; cur < end; cur = cur + le16_to_cpu(tl.fc_len) + sizeof(tl)) {
                memcpy(&tl, cur, sizeof(tl));
                val = cur + sizeof(tl);

                if (state->fc_replay_num_tags == 0)
                        goto replay_done;
                jbd_debug(3, "Replay phase processing %s tag\n",
                                tag2str(le16_to_cpu(tl.fc_tag)));
                state->fc_replay_num_tags--;
                switch (le16_to_cpu(tl.fc_tag)) {
                case EXT4_FC_TAG_CREAT:
                case EXT4_FC_TAG_LINK:
                        ret = ext4_fc_handle_link_and_create(ctx, &tl, val);
                        break;
                case EXT4_FC_TAG_UNLINK:
                        ret = ext4_fc_handle_unlink(ctx, &tl, val);
                        break;
                case EXT4_FC_TAG_ADD_RANGE:
                        ret = ext4_fc_handle_add_extent(ctx, val);
                        break;
                case EXT4_FC_TAG_DEL_RANGE:
                        ret = ext4_fc_handle_del_range(ctx, val);
                        break;
                case EXT4_FC_TAG_INODE:
                        ret = ext4_fc_handle_inode(ctx, val);
                        break;
                case EXT4_FC_TAG_TAIL:
                        ext4_fc_flush_extents(ctx, 0);
                case EXT4_FC_TAG_PAD:
                case EXT4_FC_TAG_HEAD:
                        break;
                default:
                        ret = -ECANCELED;
                        break;
                }
                if (ret < 0)
                        break;
                ret = JBD2_FC_REPLAY_CONTINUE;
        }
        return ret;
replay_done:
        jbd_debug(1, "End of fast commit replay\n");
        if (state->fc_current_pass != pass)
                return JBD2_FC_REPLAY_STOP;

        ext2fs_calculate_summary_stats(ctx->fs, 0 /* update bg also */);
        ext2fs_write_block_bitmap(ctx->fs);
        ext2fs_write_inode_bitmap(ctx->fs);
        ext2fs_mark_super_dirty(ctx->fs);
        ext2fs_set_gdt_csum(ctx->fs);
        ctx->fs->super->s_state = state->fc_super_state;
        ext2fs_flush(ctx->fs);

        return JBD2_FC_REPLAY_STOP;
}

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                     ret;
        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)) {
                /*
                 * The full set of superblock sanity checks haven't
                 * been performed yet, so we need to do some basic
                 * checks here to avoid potential array overruns.
                 */
                if (!sb->s_journal_inum ||
                    (sb->s_journal_inum >
                     (ctx->fs->group_desc_count * sb->s_inodes_per_group))) {
                        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) ||
                    (j_inode->i_ext2.i_flags & EXT4_ENCRYPT_FL)) {
                        retval = EXT2_ET_NO_JOURNAL;
                        goto try_backup_journal;
                }
                if (EXT2_I_SIZE(&j_inode->i_ext2) / journal->j_blocksize <
                    JBD2_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_total_len = 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 ((ret = jbd2_journal_bmap(journal, 0, &start)) != 0) {
                        retval = (errcode_t) (-1 * ret);
                        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(REQ_OP_READ, 0, 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_total_len = (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;
        if (ext2fs_has_feature_fast_commit(ctx->fs->super))
                journal->j_fc_replay_callback = ext4_fc_replay;
        else
                journal->j_fc_replay_callback = NULL;

#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(REQ_OP_READ, 0, 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 JBD2_MAGIC, we probably have a wrong inode */
        if (jsb->s_header.h_magic != htonl(JBD2_MAGIC_NUMBER))
                return e2fsck_journal_fix_bad_inode(ctx, &pctx);

        switch (ntohl(jsb->s_header.h_blocktype)) {
        case JBD2_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 JBD2_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 JBD2_DESCRIPTOR_BLOCK:
        case JBD2_COMMIT_BLOCK:
        case JBD2_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 (JBD2_HAS_INCOMPAT_FEATURE(journal, ~JBD2_KNOWN_INCOMPAT_FEATURES))
                return EXT2_ET_UNSUPP_FEATURE;

        if (JBD2_HAS_RO_COMPAT_FEATURE(journal, ~JBD2_KNOWN_ROCOMPAT_FEATURES))
                return EXT2_ET_RO_UNSUPP_FEATURE;

        /* Checksum v1-3 are mutually exclusive features. */
        if (jbd2_has_feature_csum2(journal) && jbd2_has_feature_csum3(journal))
                return EXT2_ET_CORRUPT_JOURNAL_SB;

        if (jbd2_journal_has_csum_v2or3(journal) &&
            jbd2_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 (jbd2_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_total_len)
                journal->j_total_len = ntohl(jsb->s_maxlen);
        else if (ntohl(jsb->s_maxlen) > journal->j_total_len) {
                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);
        if (jbd2_has_feature_fast_commit(journal)) {
                if (ntohl(jsb->s_maxlen) - jbd2_journal_get_num_fc_blks(jsb)
                        < JBD2_MIN_JOURNAL_BLOCKS) {
                        com_err(ctx->program_name, EXT2_ET_CORRUPT_JOURNAL_SB,
                                _("%s: incorrect fast commit blocks\n"),
                                ctx->device_name);
                        return EXT2_ET_CORRUPT_JOURNAL_SB;
                }
                journal->j_fc_last = ntohl(jsb->s_maxlen);
                journal->j_last = journal->j_fc_last -
                                        jbd2_journal_get_num_fc_blks(jsb);
                journal->j_fc_first = journal->j_last + 1;
        } else {
                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(JBD2_MAGIC_NUMBER) ||
            jsb->s_header.h_blocktype != htonl(JBD2_SUPERBLOCK_V1)) {
                jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
                jsb->s_header.h_blocktype = htonl(JBD2_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_total_len);
        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(REQ_OP_WRITE, 0, 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);

        retval = jbd2_journal_init_revoke_record_cache();
        if (retval)
                return retval;

        retval = jbd2_journal_init_revoke_table_cache();
        if (retval)
                return retval;

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

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

        retval = jbd2_journal_init_revoke(journal, 1024);
        if (retval)
                goto errout;

        retval = -jbd2_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:
        jbd2_journal_destroy_revoke(journal);
        jbd2_journal_destroy_revoke_record_cache();
        jbd2_journal_destroy_revoke_table_cache();
        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;
}