e2fsck: update the quota records when the root directory is recreated

[thirdparty/e2fsprogs.git] / e2fsck / pass3.c

/*
 * pass3.c -- pass #3 of e2fsck: Check for directory connectivity
 *
 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999 Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 *
 * Pass #3 assures that all directories are connected to the
 * filesystem tree, using the following algorithm:
 *
 * First, the root directory is checked to make sure it exists; if
 * not, e2fsck will offer to create a new one.  It is then marked as
 * "done".
 *
 * Then, pass3 iterates over all directory inodes; for each directory
 * it attempts to trace up the filesystem tree, using dirinfo.parent
 * until it reaches a directory which has been marked "done".  If it
 * can not do so, then the directory must be disconnected, and e2fsck
 * will offer to reconnect it to /lost+found.  While it is chasing
 * parent pointers up the filesystem tree, if pass3 sees a directory
 * twice, then it has detected a filesystem loop, and it will again
 * offer to reconnect the directory to /lost+found in to break the
 * filesystem loop.
 *
 * Pass 3 also contains the subroutine, e2fsck_reconnect_file() to
 * reconnect inodes to /lost+found; this subroutine is also used by
 * pass 4.  e2fsck_reconnect_file() calls get_lost_and_found(), which
 * is responsible for creating /lost+found if it does not exist.
 *
 * Pass 3 frees the following data structures:
 *      - The dirinfo directory information cache.
 */

#include "config.h"
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif

#include "e2fsck.h"
#include "problem.h"

static void check_root(e2fsck_t ctx);
static int check_directory(e2fsck_t ctx, ext2_ino_t ino,
                           struct problem_context *pctx);
static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent);

static ext2fs_inode_bitmap inode_loop_detect = 0;
static ext2fs_inode_bitmap inode_done_map = 0;

void e2fsck_pass3(e2fsck_t ctx)
{
        ext2_filsys fs = ctx->fs;
        struct dir_info_iter *iter = NULL;
#ifdef RESOURCE_TRACK
        struct resource_track   rtrack;
#endif
        struct problem_context  pctx;
        struct dir_info *dir;
        unsigned long maxdirs, count;

        init_resource_track(&rtrack, ctx->fs->io);
        clear_problem_context(&pctx);

#ifdef MTRACE
        mtrace_print("Pass 3");
#endif

        if (!(ctx->options & E2F_OPT_PREEN))
                fix_problem(ctx, PR_3_PASS_HEADER, &pctx);

        /*
         * Allocate some bitmaps to do loop detection.
         */
        pctx.errcode = e2fsck_allocate_inode_bitmap(fs, _("inode done bitmap"),
                                        EXT2FS_BMAP64_AUTODIR,
                                        "inode_done_map", &inode_done_map);
        if (pctx.errcode) {
                pctx.num = 2;
                fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx);
                ctx->flags |= E2F_FLAG_ABORT;
                goto abort_exit;
        }
        print_resource_track(ctx, _("Peak memory"), &ctx->global_rtrack, NULL);

        check_root(ctx);
        if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
                goto abort_exit;

        ext2fs_mark_inode_bitmap2(inode_done_map, EXT2_ROOT_INO);

        maxdirs = e2fsck_get_num_dirinfo(ctx);
        count = 1;

        if (ctx->progress)
                if ((ctx->progress)(ctx, 3, 0, maxdirs))
                        goto abort_exit;

        iter = e2fsck_dir_info_iter_begin(ctx);
        while ((dir = e2fsck_dir_info_iter(ctx, iter)) != 0) {
                if (ctx->flags & E2F_FLAG_SIGNAL_MASK ||
                    ctx->flags & E2F_FLAG_RESTART)
                        goto abort_exit;
                if (ctx->progress && (ctx->progress)(ctx, 3, count++, maxdirs))
                        goto abort_exit;
                if (ext2fs_test_inode_bitmap2(ctx->inode_dir_map, dir->ino))
                        if (check_directory(ctx, dir->ino, &pctx))
                                goto abort_exit;
        }

        /*
         * Force the creation of /lost+found if not present
         */
        if ((ctx->options & E2F_OPT_READONLY) == 0)
                e2fsck_get_lost_and_found(ctx, 1);

        /*
         * If there are any directories that need to be indexed or
         * optimized, do it here.
         */
        e2fsck_rehash_directories(ctx);

abort_exit:
        if (iter)
                e2fsck_dir_info_iter_end(ctx, iter);
        e2fsck_free_dir_info(ctx);
        if (inode_loop_detect) {
                ext2fs_free_inode_bitmap(inode_loop_detect);
                inode_loop_detect = 0;
        }
        if (inode_done_map) {
                ext2fs_free_inode_bitmap(inode_done_map);
                inode_done_map = 0;
        }

        if (ctx->lnf_repair_block) {
                ext2fs_unmark_block_bitmap2(ctx->block_found_map,
                                            ctx->lnf_repair_block);
                ctx->lnf_repair_block = 0;
        }
        if (ctx->root_repair_block) {
                ext2fs_unmark_block_bitmap2(ctx->block_found_map,
                                            ctx->root_repair_block);
                ctx->root_repair_block = 0;
        }

        print_resource_track(ctx, _("Pass 3"), &rtrack, ctx->fs->io);
}

/*
 * This makes sure the root inode is present; if not, we ask if the
 * user wants us to create it.  Not creating it is a fatal error.
 */
static void check_root(e2fsck_t ctx)
{
        ext2_filsys fs = ctx->fs;
        blk64_t                 blk;
        struct ext2_inode_large inode;
        struct ext2_inode       *iptr = (struct ext2_inode *) &inode;
        char *                  block;
        struct problem_context  pctx;

        clear_problem_context(&pctx);

        if (ext2fs_test_inode_bitmap2(ctx->inode_used_map, EXT2_ROOT_INO)) {
                /*
                 * If the root inode is not a directory, die here.  The
                 * user must have answered 'no' in pass1 when we
                 * offered to clear it.
                 */
                if (!(ext2fs_test_inode_bitmap2(ctx->inode_dir_map,
                                               EXT2_ROOT_INO))) {
                        fix_problem(ctx, PR_3_ROOT_NOT_DIR_ABORT, &pctx);
                        ctx->flags |= E2F_FLAG_ABORT;
                }
                return;
        }

        if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) {
                fix_problem(ctx, PR_3_NO_ROOT_INODE_ABORT, &pctx);
                ctx->flags |= E2F_FLAG_ABORT;
                return;
        }

        e2fsck_read_bitmaps(ctx);

        /*
         * First, find a free block
         */
        if (ctx->root_repair_block) {
                blk = ctx->root_repair_block;
                ctx->root_repair_block = 0;
                goto skip_new_block;
        }
        pctx.errcode = ext2fs_new_block2(fs, 0, ctx->block_found_map, &blk);
        if (pctx.errcode) {
                pctx.str = "ext2fs_new_block";
                fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
                ctx->flags |= E2F_FLAG_ABORT;
                return;
        }
        ext2fs_mark_block_bitmap2(ctx->block_found_map, blk);
skip_new_block:
        ext2fs_mark_block_bitmap2(fs->block_map, blk);
        ext2fs_mark_bb_dirty(fs);

        /*
         * Set up the inode structure
         */
        memset(&inode, 0, sizeof(inode));
        inode.i_mode = 040755;
        inode.i_size = fs->blocksize;
        inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now;
        inode.i_links_count = 2;
        ext2fs_iblk_set(fs, iptr, 1);
        inode.i_block[0] = blk;
        inode.i_extra_isize = sizeof(struct ext2_inode_large) -
                EXT2_GOOD_OLD_INODE_SIZE;

        /*
         * Write out the inode.
         */
        pctx.errcode = ext2fs_write_new_inode(fs, EXT2_ROOT_INO, iptr);
        if (pctx.errcode) {
                pctx.str = "ext2fs_write_inode";
                fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
                ctx->flags |= E2F_FLAG_ABORT;
                return;
        }

        /*
         * Now let's create the actual data block for the inode.
         * Due to metadata_csum, we must write the dir blocks AFTER
         * the inode has been written to disk!
         */
        pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO,
                                            &block);
        if (pctx.errcode) {
                pctx.str = "ext2fs_new_dir_block";
                fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
                ctx->flags |= E2F_FLAG_ABORT;
                return;
        }

        pctx.errcode = ext2fs_write_dir_block4(fs, blk, block, 0,
                                               EXT2_ROOT_INO);
        ext2fs_free_mem(&block);
        if (pctx.errcode) {
                pctx.str = "ext2fs_write_dir_block4";
                fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
                ctx->flags |= E2F_FLAG_ABORT;
                return;
        }

        /*
         * Miscellaneous bookkeeping...
         */
        e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO);
        ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2);
        ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2);

        ext2fs_mark_inode_bitmap2(ctx->inode_used_map, EXT2_ROOT_INO);
        ext2fs_mark_inode_bitmap2(ctx->inode_dir_map, EXT2_ROOT_INO);
        ext2fs_mark_inode_bitmap2(fs->inode_map, EXT2_ROOT_INO);
        ext2fs_mark_ib_dirty(fs);
        quota_data_add(ctx->qctx, &inode, EXT2_ROOT_INO,
                       EXT2_CLUSTER_SIZE(fs->super));
        quota_data_inodes(ctx->qctx, &inode, EXT2_ROOT_INO, +1);
}

/*
 * This subroutine is responsible for making sure that a particular
 * directory is connected to the root; if it isn't we trace it up as
 * far as we can go, and then offer to connect the resulting parent to
 * the lost+found.  We have to do loop detection; if we ever discover
 * a loop, we treat that as a disconnected directory and offer to
 * reparent it to lost+found.
 *
 * However, loop detection is expensive, because for very large
 * filesystems, the inode_loop_detect bitmap is huge, and clearing it
 * is non-trivial.  Loops in filesystems are also a rare error case,
 * and we shouldn't optimize for error cases.  So we try two passes of
 * the algorithm.  The first time, we ignore loop detection and merely
 * increment a counter; if the counter exceeds some extreme threshold,
 * then we try again with the loop detection bitmap enabled.
 */
static int check_directory(e2fsck_t ctx, ext2_ino_t dir,
                           struct problem_context *pctx)
{
        ext2_filsys     fs = ctx->fs;
        ext2_ino_t      ino = dir, parent;
        int             loop_pass = 0, parent_count = 0;

        while (1) {
                /*
                 * Mark this inode as being "done"; by the time we
                 * return from this function, the inode we either be
                 * verified as being connected to the directory tree,
                 * or we will have offered to reconnect this to
                 * lost+found.
                 *
                 * If it was marked done already, then we've reached a
                 * parent we've already checked.
                 */
                if (ext2fs_mark_inode_bitmap2(inode_done_map, ino))
                        break;

                if (e2fsck_dir_info_get_parent(ctx, ino, &parent)) {
                        fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
                        return 0;
                }

                /*
                 * If this directory doesn't have a parent, or we've
                 * seen the parent once already, then offer to
                 * reparent it to lost+found
                 */
                if (!parent ||
                    (loop_pass &&
                     (ext2fs_test_inode_bitmap2(inode_loop_detect,
                                               parent)))) {
                        pctx->ino = ino;
                        if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
                                if (e2fsck_reconnect_file(ctx, pctx->ino))
                                        ext2fs_unmark_valid(fs);
                                else {
                                        fix_dotdot(ctx, pctx->ino,
                                                   ctx->lost_and_found);
                                        parent = ctx->lost_and_found;
                                }
                        }
                        break;
                }
                ino = parent;
                if (loop_pass) {
                        ext2fs_mark_inode_bitmap2(inode_loop_detect, ino);
                } else if (parent_count++ > 2048) {
                        /*
                         * If we've run into a path depth that's
                         * greater than 2048, try again with the inode
                         * loop bitmap turned on and start from the
                         * top.
                         */
                        loop_pass = 1;
                        if (inode_loop_detect)
                                ext2fs_clear_inode_bitmap(inode_loop_detect);
                        else {
                                pctx->errcode = e2fsck_allocate_inode_bitmap(fs, _("inode loop detection bitmap"), EXT2FS_BMAP64_AUTODIR, "inode_loop_detect", &inode_loop_detect);
                                if (pctx->errcode) {
                                        pctx->num = 1;
                                        fix_problem(ctx,
                                    PR_3_ALLOCATE_IBITMAP_ERROR, pctx);
                                        ctx->flags |= E2F_FLAG_ABORT;
                                        return -1;
                                }
                        }
                        ino = dir;
                }
        }

        /*
         * Make sure that .. and the parent directory are the same;
         * offer to fix it if not.
         */
        pctx->ino = dir;
        if (e2fsck_dir_info_get_dotdot(ctx, dir, &pctx->ino2) ||
            e2fsck_dir_info_get_parent(ctx, dir, &pctx->dir)) {
                fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
                return 0;
        }
        if (pctx->ino2 != pctx->dir) {
                if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
                        fix_dotdot(ctx, dir, pctx->dir);
        }
        return 0;
}

/*
 * This routine gets the lost_and_found inode, making it a directory
 * if necessary
 */
ext2_ino_t e2fsck_get_lost_and_found(e2fsck_t ctx, int fix)
{
        ext2_filsys fs = ctx->fs;
        ext2_ino_t                      ino;
        blk64_t                 blk;
        errcode_t               retval;
        struct ext2_inode_large inode;
        char *                  block;
        static const char       name[] = "lost+found";
        struct  problem_context pctx;
        int                     will_rehash, flags;

        if (ctx->lost_and_found)
                return ctx->lost_and_found;

        clear_problem_context(&pctx);

        will_rehash = e2fsck_dir_will_be_rehashed(ctx, EXT2_ROOT_INO);
        if (will_rehash) {
                flags = ctx->fs->flags;
                ctx->fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
        }
        retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
                               sizeof(name)-1, 0, &ino);
        if (will_rehash)
                ctx->fs->flags = (flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) |
                        (ctx->fs->flags & ~EXT2_FLAG_IGNORE_CSUM_ERRORS);
        if (retval && !fix)
                return 0;
        if (!retval) {
                /* Lost+found shouldn't have inline data */
                retval = ext2fs_read_inode_full(fs, ino, EXT2_INODE(&inode),
                                                sizeof(inode));
                if (fix && retval)
                        return 0;

                if (fix && (inode.i_flags & EXT4_INLINE_DATA_FL)) {
                        if (!fix_problem(ctx, PR_3_LPF_INLINE_DATA, &pctx))
                                return 0;
                        goto unlink;
                }

                if (fix && (inode.i_flags & EXT4_ENCRYPT_FL)) {
                        if (!fix_problem(ctx, PR_3_LPF_ENCRYPTED, &pctx))
                                return 0;
                        goto unlink;
                }

                if (ext2fs_check_directory(fs, ino) == 0) {
                        ctx->lost_and_found = ino;
                        return ino;
                }

                /* Lost+found isn't a directory! */
                if (!fix)
                        return 0;
                pctx.ino = ino;
                if (!fix_problem(ctx, PR_3_LPF_NOTDIR, &pctx))
                        return 0;

unlink:
                /* OK, unlink the old /lost+found file. */
                pctx.errcode = ext2fs_unlink(fs, EXT2_ROOT_INO, name, ino, 0);
                if (pctx.errcode) {
                        pctx.str = "ext2fs_unlink";
                        fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
                        return 0;
                }
                (void) e2fsck_dir_info_set_parent(ctx, ino, 0);
                e2fsck_adjust_inode_count(ctx, ino, -1);
                /*
                 * If the old lost+found was a directory, we've just
                 * disconnected it from the directory tree, which
                 * means we need to restart the directory tree scan.
                 * The simplest way to do this is restart the whole
                 * e2fsck operation.
                 */
                if (LINUX_S_ISDIR(inode.i_mode))
                        ctx->flags |= E2F_FLAG_RESTART;
        } else if (retval != EXT2_ET_FILE_NOT_FOUND) {
                pctx.errcode = retval;
                fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
        }
        if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
                return 0;

        /*
         * Read the inode and block bitmaps in; we'll be messing with
         * them.
         */
        e2fsck_read_bitmaps(ctx);

        /*
         * First, find a free block
         */
        if (ctx->lnf_repair_block) {
                blk = ctx->lnf_repair_block;
                ctx->lnf_repair_block = 0;
                goto skip_new_block;
        }
        retval = ext2fs_new_block2(fs, 0, ctx->block_found_map, &blk);
        if (retval == EXT2_ET_BLOCK_ALLOC_FAIL &&
            fix_problem(ctx, PR_3_LPF_NO_SPACE, &pctx)) {
                fix_problem(ctx, PR_3_NO_SPACE_TO_RECOVER, &pctx);
                ctx->lost_and_found = EXT2_ROOT_INO;
                return 0;
        }
        if (retval) {
                pctx.errcode = retval;
                fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
                return 0;
        }
        ext2fs_mark_block_bitmap2(ctx->block_found_map, blk);
skip_new_block:
        ext2fs_block_alloc_stats2(fs, blk, +1);

        /*
         * Next find a free inode.
         */
        retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040700,
                                  ctx->inode_used_map, &ino);
        if (retval == EXT2_ET_INODE_ALLOC_FAIL &&
            fix_problem(ctx, PR_3_LPF_NO_SPACE, &pctx)) {
                fix_problem(ctx, PR_3_NO_SPACE_TO_RECOVER, &pctx);
                ctx->lost_and_found = EXT2_ROOT_INO;
                return 0;
        }
        if (retval) {
                pctx.errcode = retval;
                fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx);
                return 0;
        }
        ext2fs_mark_inode_bitmap2(ctx->inode_used_map, ino);
        ext2fs_mark_inode_bitmap2(ctx->inode_dir_map, ino);
        ext2fs_inode_alloc_stats2(fs, ino, +1, 1);

        /*
         * Set up the inode structure
         */
        memset(&inode, 0, sizeof(inode));
        inode.i_mode = 040700;
        inode.i_size = fs->blocksize;
        inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now;
        inode.i_links_count = 2;
        ext2fs_iblk_set(fs, EXT2_INODE(&inode), 1);
        inode.i_block[0] = blk;

        /*
         * Next, write out the inode.
         */
        pctx.errcode = ext2fs_write_new_inode(fs, ino, EXT2_INODE(&inode));
        if (pctx.errcode) {
                pctx.str = "ext2fs_write_inode";
                fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
                return 0;
        }

        /*
         * Now let's create the actual data block for the inode.
         * Due to metadata_csum, the directory block MUST be written
         * after the inode is written to disk!
         */
        retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
        if (retval) {
                pctx.errcode = retval;
                fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx);
                return 0;
        }

        retval = ext2fs_write_dir_block4(fs, blk, block, 0, ino);
        ext2fs_free_mem(&block);
        if (retval) {
                pctx.errcode = retval;
                fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx);
                return 0;
        }

        /*
         * Finally, create the directory link
         */
        pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, EXT2_FT_DIR);
        if (pctx.errcode == EXT2_ET_DIR_NO_SPACE) {
                pctx.errcode = ext2fs_expand_dir(fs, EXT2_ROOT_INO);
                if (pctx.errcode)
                        goto link_error;
                pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino,
                                           EXT2_FT_DIR);
        }
        if (pctx.errcode) {
link_error:
                pctx.str = "ext2fs_link";
                fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
                return 0;
        }

        /*
         * Miscellaneous bookkeeping that needs to be kept straight.
         */
        e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO);
        e2fsck_adjust_inode_count(ctx, EXT2_ROOT_INO, 1);
        ext2fs_icount_store(ctx->inode_count, ino, 2);
        ext2fs_icount_store(ctx->inode_link_info, ino, 2);
        ctx->lost_and_found = ino;
        quota_data_add(ctx->qctx, &inode, ino, EXT2_CLUSTER_SIZE(fs->super));
        quota_data_inodes(ctx->qctx, &inode, ino, +1);
#if 0
        printf("/lost+found created; inode #%lu\n", ino);
#endif
        return ino;
}

/*
 * This routine will connect a file to lost+found
 */
int e2fsck_reconnect_file(e2fsck_t ctx, ext2_ino_t ino)
{
        ext2_filsys fs = ctx->fs;
        errcode_t       retval;
        char            name[80];
        struct problem_context  pctx;
        struct ext2_inode       inode;
        int             file_type = 0;

        clear_problem_context(&pctx);
        pctx.ino = ino;

        if (!ctx->bad_lost_and_found && !ctx->lost_and_found) {
                if (e2fsck_get_lost_and_found(ctx, 1) == 0)
                        ctx->bad_lost_and_found++;
        }
        if (ctx->bad_lost_and_found) {
                fix_problem(ctx, PR_3_NO_LPF, &pctx);
                return 1;
        }

        sprintf(name, "#%u", ino);
        if (ext2fs_read_inode(fs, ino, &inode) == 0)
                file_type = ext2_file_type(inode.i_mode);
        retval = ext2fs_link(fs, ctx->lost_and_found, name, ino, file_type);
        if (retval == EXT2_ET_DIR_NO_SPACE) {
                if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
                        return 1;
                retval = e2fsck_expand_directory(ctx, ctx->lost_and_found,
                                                 1, 0);
                if (retval) {
                        pctx.errcode = retval;
                        fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
                        return 1;
                }
                retval = ext2fs_link(fs, ctx->lost_and_found, name,
                                     ino, file_type);
        }
        if (retval) {
                pctx.errcode = retval;
                fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
                return 1;
        }
        e2fsck_adjust_inode_count(ctx, ino, 1);

        return 0;
}

/*
 * Utility routine to adjust the inode counts on an inode.
 */
errcode_t e2fsck_adjust_inode_count(e2fsck_t ctx, ext2_ino_t ino, int adj)
{
        ext2_filsys fs = ctx->fs;
        errcode_t               retval;
        struct ext2_inode       inode;

        if (!ino)
                return 0;

        retval = ext2fs_read_inode(fs, ino, &inode);
        if (retval)
                return retval;

#if 0
        printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
               inode.i_links_count);
#endif

        if (adj == 1) {
                ext2fs_icount_increment(ctx->inode_count, ino, 0);
                if (inode.i_links_count == (__u16) ~0)
                        return 0;
                ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
                inode.i_links_count++;
        } else if (adj == -1) {
                ext2fs_icount_decrement(ctx->inode_count, ino, 0);
                if (inode.i_links_count == 0)
                        return 0;
                ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
                inode.i_links_count--;
        }

        retval = ext2fs_write_inode(fs, ino, &inode);
        if (retval)
                return retval;

        return 0;
}

/*
 * Fix parent --- this routine fixes up the parent of a directory.
 */
struct fix_dotdot_struct {
        ext2_filsys     fs;
        ext2_ino_t      parent;
        int             done;
        e2fsck_t        ctx;
};

static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
                           int  offset EXT2FS_ATTR((unused)),
                           int  blocksize EXT2FS_ATTR((unused)),
                           char *buf EXT2FS_ATTR((unused)),
                           void *priv_data)
{
        struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data;
        errcode_t       retval;
        struct problem_context pctx;

        if (ext2fs_dirent_name_len(dirent) != 2)
                return 0;
        if (strncmp(dirent->name, "..", 2))
                return 0;

        clear_problem_context(&pctx);

        retval = e2fsck_adjust_inode_count(fp->ctx, dirent->inode, -1);
        if (retval) {
                pctx.errcode = retval;
                fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
        }
        retval = e2fsck_adjust_inode_count(fp->ctx, fp->parent, 1);
        if (retval) {
                pctx.errcode = retval;
                fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
        }
        dirent->inode = fp->parent;
        if (ext2fs_has_feature_filetype(fp->ctx->fs->super))
                ext2fs_dirent_set_file_type(dirent, EXT2_FT_DIR);
        else
                ext2fs_dirent_set_file_type(dirent, EXT2_FT_UNKNOWN);

        fp->done++;
        return DIRENT_ABORT | DIRENT_CHANGED;
}

static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
{
        ext2_filsys fs = ctx->fs;
        errcode_t       retval;
        struct fix_dotdot_struct fp;
        struct problem_context pctx;
        int             flags, will_rehash;

        fp.fs = fs;
        fp.parent = parent;
        fp.done = 0;
        fp.ctx = ctx;

#if 0
        printf("Fixing '..' of inode %lu to be %lu...\n", ino, parent);
#endif

        clear_problem_context(&pctx);
        pctx.ino = ino;
        will_rehash = e2fsck_dir_will_be_rehashed(ctx, ino);
        if (will_rehash) {
                flags = ctx->fs->flags;
                ctx->fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
        }
        retval = ext2fs_dir_iterate(fs, ino, DIRENT_FLAG_INCLUDE_EMPTY,
                                    0, fix_dotdot_proc, &fp);
        if (will_rehash)
                ctx->fs->flags = (flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) |
                        (ctx->fs->flags & ~EXT2_FLAG_IGNORE_CSUM_ERRORS);
        if (retval || !fp.done) {
                pctx.errcode = retval;
                fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR :
                            PR_3_FIX_PARENT_NOFIND, &pctx);
                ext2fs_unmark_valid(fs);
        }
        (void) e2fsck_dir_info_set_dotdot(ctx, ino, parent);
        if (e2fsck_dir_info_set_parent(ctx, ino, ctx->lost_and_found))
                fix_problem(ctx, PR_3_NO_DIRINFO, &pctx);

        return;
}

/*
 * These routines are responsible for expanding a /lost+found if it is
 * too small.
 */

struct expand_dir_struct {
        blk64_t                 num;
        e2_blkcnt_t             guaranteed_size;
        blk64_t                 newblocks;
        blk64_t                 last_block;
        errcode_t               err;
        e2fsck_t                ctx;
        ext2_ino_t              dir;
};

static int expand_dir_proc(ext2_filsys fs,
                           blk64_t      *blocknr,
                           e2_blkcnt_t  blockcnt,
                           blk64_t ref_block EXT2FS_ATTR((unused)),
                           int ref_offset EXT2FS_ATTR((unused)),
                           void *priv_data)
{
        struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
        blk64_t new_blk;
        static blk64_t  last_blk = 0;
        char            *block;
        errcode_t       retval;
        e2fsck_t        ctx;

        ctx = es->ctx;

        if (es->guaranteed_size && blockcnt >= es->guaranteed_size)
                return BLOCK_ABORT;

        if (blockcnt > 0)
                es->last_block = blockcnt;
        if (*blocknr) {
                last_blk = *blocknr;
                return 0;
        }

        if (blockcnt &&
            (EXT2FS_B2C(fs, last_blk) == EXT2FS_B2C(fs, last_blk + 1)))
                new_blk = last_blk + 1;
        else {
                last_blk &= ~EXT2FS_CLUSTER_MASK(fs);
                retval = ext2fs_new_block2(fs, last_blk, ctx->block_found_map,
                                          &new_blk);
                if (retval) {
                        es->err = retval;
                        return BLOCK_ABORT;
                }
                es->newblocks++;
                ext2fs_block_alloc_stats2(fs, new_blk, +1);
        }
        last_blk = new_blk;

        if (blockcnt > 0) {
                retval = ext2fs_new_dir_block(fs, 0, 0, &block);
                if (retval) {
                        es->err = retval;
                        return BLOCK_ABORT;
                }
                es->num--;
                retval = ext2fs_write_dir_block4(fs, new_blk, block, 0,
                                                 es->dir);
                ext2fs_free_mem(&block);
        } else
                retval = ext2fs_zero_blocks2(fs, new_blk, 1, NULL, NULL);
        if (retval) {
                es->err = retval;
                return BLOCK_ABORT;
        }
        *blocknr = new_blk;
        ext2fs_mark_block_bitmap2(ctx->block_found_map, new_blk);

        if (es->num == 0)
                return (BLOCK_CHANGED | BLOCK_ABORT);
        else
                return BLOCK_CHANGED;
}

errcode_t e2fsck_expand_directory(e2fsck_t ctx, ext2_ino_t dir,
                                  int num, int guaranteed_size)
{
        ext2_filsys fs = ctx->fs;
        errcode_t       retval;
        struct expand_dir_struct es;
        struct ext2_inode_large inode;
        blk64_t         sz;

        if (!(fs->flags & EXT2_FLAG_RW))
                return EXT2_ET_RO_FILSYS;

        /*
         * Read the inode and block bitmaps in; we'll be messing with
         * them.
         */
        e2fsck_read_bitmaps(ctx);

        retval = ext2fs_check_directory(fs, dir);
        if (retval)
                return retval;

        es.num = num;
        es.guaranteed_size = guaranteed_size;
        es.last_block = 0;
        es.err = 0;
        es.newblocks = 0;
        es.ctx = ctx;
        es.dir = dir;

        retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_APPEND,
                                       0, expand_dir_proc, &es);

        if (es.err)
                return es.err;

        /*
         * Update the size and block count fields in the inode.
         */
        retval = ext2fs_read_inode_full(fs, dir,
                                        EXT2_INODE(&inode), sizeof(inode));
        if (retval)
                return retval;

        sz = (es.last_block + 1) * fs->blocksize;
        retval = ext2fs_inode_size_set(fs, EXT2_INODE(&inode), sz);
        if (retval)
                return retval;
        ext2fs_iblk_add_blocks(fs, EXT2_INODE(&inode), es.newblocks);
        quota_data_add(ctx->qctx, &inode, dir,
                       es.newblocks * EXT2_CLUSTER_SIZE(fs->super));

        e2fsck_write_inode_full(ctx, dir, EXT2_INODE(&inode),
                                sizeof(inode), "expand_directory");

        return 0;
}