[PATCH] ext4: initial copy of files from ext3

Start of the ext4 patch series.  See Documentation/filesystems/ext4.txt for
details.

This is a simple copy of the files in fs/ext3 to fs/ext4 and
/usr/incude/linux/ext3* to /usr/include/ex4*

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 758 insertions, 0 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
new file mode 100644
index 000000000000..e45dbd651736
--- /dev/null
+++ b/fs/ext4/ialloc.c
@@ -0,0 +1,758 @@
+/*
+ *  linux/fs/ext3/ialloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  BSD ufs-inspired inode and directory allocation by
+ *  Stephen Tweedie (sct@redhat.com), 1993
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/random.h>
+#include <linux/bitops.h>
+
+#include <asm/byteorder.h>
+
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * ialloc.c contains the inodes allocation and deallocation routines
+ */
+
+/*
+ * The free inodes are managed by bitmaps.  A file system contains several
+ * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
+ * block for inodes, N blocks for the inode table and data blocks.
+ *
+ * The file system contains group descriptors which are located after the
+ * super block.  Each descriptor contains the number of the bitmap block and
+ * the free blocks count in the block.
+ */
+
+
+/*
+ * Read the inode allocation bitmap for a given block_group, reading
+ * into the specified slot in the superblock's bitmap cache.
+ *
+ * Return buffer_head of bitmap on success or NULL.
+ */
+static struct buffer_head *
+read_inode_bitmap(struct super_block * sb, unsigned long block_group)
+{
+        struct ext3_group_desc *desc;
+        struct buffer_head *bh = NULL;
+
+        desc = ext3_get_group_desc(sb, block_group, NULL);
+        if (!desc)
+                goto error_out;
+
+        bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
+        if (!bh)
+                ext3_error(sb, "read_inode_bitmap",
+                            "Cannot read inode bitmap - "
+                            "block_group = %lu, inode_bitmap = %u",
+                            block_group, le32_to_cpu(desc->bg_inode_bitmap));
+error_out:
+        return bh;
+}
+
+/*
+ * NOTE! When we get the inode, we're the only people
+ * that have access to it, and as such there are no
+ * race conditions we have to worry about. The inode
+ * is not on the hash-lists, and it cannot be reached
+ * through the filesystem because the directory entry
+ * has been deleted earlier.
+ *
+ * HOWEVER: we must make sure that we get no aliases,
+ * which means that we have to call "clear_inode()"
+ * _before_ we mark the inode not in use in the inode
+ * bitmaps. Otherwise a newly created file might use
+ * the same inode number (not actually the same pointer
+ * though), and then we'd have two inodes sharing the
+ * same inode number and space on the harddisk.
+ */
+void ext3_free_inode (handle_t *handle, struct inode * inode)
+{
+        struct super_block * sb = inode->i_sb;
+        int is_directory;
+        unsigned long ino;
+        struct buffer_head *bitmap_bh = NULL;
+        struct buffer_head *bh2;
+        unsigned long block_group;
+        unsigned long bit;
+        struct ext3_group_desc * gdp;
+        struct ext3_super_block * es;
+        struct ext3_sb_info *sbi;
+        int fatal = 0, err;
+
+        if (atomic_read(&inode->i_count) > 1) {
+                printk ("ext3_free_inode: inode has count=%d\n",
+                                        atomic_read(&inode->i_count));
+                return;
+        }
+        if (inode->i_nlink) {
+                printk ("ext3_free_inode: inode has nlink=%d\n",
+                        inode->i_nlink);
+                return;
+        }
+        if (!sb) {
+                printk("ext3_free_inode: inode on nonexistent device\n");
+                return;
+        }
+        sbi = EXT3_SB(sb);
+
+        ino = inode->i_ino;
+        ext3_debug ("freeing inode %lu\n", ino);
+
+        /*
+         * Note: we must free any quota before locking the superblock,
+         * as writing the quota to disk may need the lock as well.
+         */
+        DQUOT_INIT(inode);
+        ext3_xattr_delete_inode(handle, inode);
+        DQUOT_FREE_INODE(inode);
+        DQUOT_DROP(inode);
+
+        is_directory = S_ISDIR(inode->i_mode);
+
+        /* Do this BEFORE marking the inode not in use or returning an error */
+        clear_inode (inode);
+
+        es = EXT3_SB(sb)->s_es;
+        if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
+                ext3_error (sb, "ext3_free_inode",
+                            "reserved or nonexistent inode %lu", ino);
+                goto error_return;
+        }
+        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
+        bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
+        bitmap_bh = read_inode_bitmap(sb, block_group);
+        if (!bitmap_bh)
+                goto error_return;
+
+        BUFFER_TRACE(bitmap_bh, "get_write_access");
+        fatal = ext3_journal_get_write_access(handle, bitmap_bh);
+        if (fatal)
+                goto error_return;
+
+        /* Ok, now we can actually update the inode bitmaps.. */
+        if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
+                                        bit, bitmap_bh->b_data))
+                ext3_error (sb, "ext3_free_inode",
+                              "bit already cleared for inode %lu", ino);
+        else {
+                gdp = ext3_get_group_desc (sb, block_group, &bh2);
+
+                BUFFER_TRACE(bh2, "get_write_access");
+                fatal = ext3_journal_get_write_access(handle, bh2);
+                if (fatal) goto error_return;
+
+                if (gdp) {
+                        spin_lock(sb_bgl_lock(sbi, block_group));
+                        gdp->bg_free_inodes_count = cpu_to_le16(
+                                le16_to_cpu(gdp->bg_free_inodes_count) + 1);
+                        if (is_directory)
+                                gdp->bg_used_dirs_count = cpu_to_le16(
+                                  le16_to_cpu(gdp->bg_used_dirs_count) - 1);
+                        spin_unlock(sb_bgl_lock(sbi, block_group));
+                        percpu_counter_inc(&sbi->s_freeinodes_counter);
+                        if (is_directory)
+                                percpu_counter_dec(&sbi->s_dirs_counter);
+
+                }
+                BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
+                err = ext3_journal_dirty_metadata(handle, bh2);
+                if (!fatal) fatal = err;
+        }
+        BUFFER_TRACE(bitmap_bh, "call ext3_journal_dirty_metadata");
+        err = ext3_journal_dirty_metadata(handle, bitmap_bh);
+        if (!fatal)
+                fatal = err;
+        sb->s_dirt = 1;
+error_return:
+        brelse(bitmap_bh);
+        ext3_std_error(sb, fatal);
+}
+
+/*
+ * There are two policies for allocating an inode.  If the new inode is
+ * a directory, then a forward search is made for a block group with both
+ * free space and a low directory-to-inode ratio; if that fails, then of
+ * the groups with above-average free space, that group with the fewest
+ * directories already is chosen.
+ *
+ * For other inodes, search forward from the parent directory\'s block
+ * group to find a free inode.
+ */
+static int find_group_dir(struct super_block *sb, struct inode *parent)
+{
+        int ngroups = EXT3_SB(sb)->s_groups_count;
+        unsigned int freei, avefreei;
+        struct ext3_group_desc *desc, *best_desc = NULL;
+        struct buffer_head *bh;
+        int group, best_group = -1;
+
+        freei = percpu_counter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
+        avefreei = freei / ngroups;
+
+        for (group = 0; group < ngroups; group++) {
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (!desc || !desc->bg_free_inodes_count)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+                        continue;
+                if (!best_desc ||
+                    (le16_to_cpu(desc->bg_free_blocks_count) >
+                     le16_to_cpu(best_desc->bg_free_blocks_count))) {
+                        best_group = group;
+                        best_desc = desc;
+                }
+        }
+        return best_group;
+}
+
+/*
+ * Orlov's allocator for directories.
+ *
+ * We always try to spread first-level directories.
+ *
+ * If there are blockgroups with both free inodes and free blocks counts
+ * not worse than average we return one with smallest directory count.
+ * Otherwise we simply return a random group.
+ *
+ * For the rest rules look so:
+ *
+ * It's OK to put directory into a group unless
+ * it has too many directories already (max_dirs) or
+ * it has too few free inodes left (min_inodes) or
+ * it has too few free blocks left (min_blocks) or
+ * it's already running too large debt (max_debt).
+ * Parent's group is prefered, if it doesn't satisfy these
+ * conditions we search cyclically through the rest. If none
+ * of the groups look good we just look for a group with more
+ * free inodes than average (starting at parent's group).
+ *
+ * Debt is incremented each time we allocate a directory and decremented
+ * when we allocate an inode, within 0--255.
+ */
+
+#define INODE_COST 64
+#define BLOCK_COST 256
+
+static int find_group_orlov(struct super_block *sb, struct inode *parent)
+{
+        int parent_group = EXT3_I(parent)->i_block_group;
+        struct ext3_sb_info *sbi = EXT3_SB(sb);
+        struct ext3_super_block *es = sbi->s_es;
+        int ngroups = sbi->s_groups_count;
+        int inodes_per_group = EXT3_INODES_PER_GROUP(sb);
+        unsigned int freei, avefreei;
+        ext3_fsblk_t freeb, avefreeb;
+        ext3_fsblk_t blocks_per_dir;
+        unsigned int ndirs;
+        int max_debt, max_dirs, min_inodes;
+        ext3_grpblk_t min_blocks;
+        int group = -1, i;
+        struct ext3_group_desc *desc;
+        struct buffer_head *bh;
+
+        freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
+        avefreei = freei / ngroups;
+        freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+        avefreeb = freeb / ngroups;
+        ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
+
+        if ((parent == sb->s_root->d_inode) ||
+            (EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) {
+                int best_ndir = inodes_per_group;
+                int best_group = -1;
+
+                get_random_bytes(&group, sizeof(group));
+                parent_group = (unsigned)group % ngroups;
+                for (i = 0; i < ngroups; i++) {
+                        group = (parent_group + i) % ngroups;
+                        desc = ext3_get_group_desc (sb, group, &bh);
+                        if (!desc || !desc->bg_free_inodes_count)
+                                continue;
+                        if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
+                                continue;
+                        if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
+                                continue;
+                        if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
+                                continue;
+                        best_group = group;
+                        best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
+                }
+                if (best_group >= 0)
+                        return best_group;
+                goto fallback;
+        }
+
+        blocks_per_dir = (le32_to_cpu(es->s_blocks_count) - freeb) / ndirs;
+
+        max_dirs = ndirs / ngroups + inodes_per_group / 16;
+        min_inodes = avefreei - inodes_per_group / 4;
+        min_blocks = avefreeb - EXT3_BLOCKS_PER_GROUP(sb) / 4;
+
+        max_debt = EXT3_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, (ext3_fsblk_t)BLOCK_COST);
+        if (max_debt * INODE_COST > inodes_per_group)
+                max_debt = inodes_per_group / INODE_COST;
+        if (max_debt > 255)
+                max_debt = 255;
+        if (max_debt == 0)
+                max_debt = 1;
+
+        for (i = 0; i < ngroups; i++) {
+                group = (parent_group + i) % ngroups;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (!desc || !desc->bg_free_inodes_count)
+                        continue;
+                if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
+                        continue;
+                return group;
+        }
+
+fallback:
+        for (i = 0; i < ngroups; i++) {
+                group = (parent_group + i) % ngroups;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (!desc || !desc->bg_free_inodes_count)
+                        continue;
+                if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
+                        return group;
+        }
+
+        if (avefreei) {
+                /*
+                 * The free-inodes counter is approximate, and for really small
+                 * filesystems the above test can fail to find any blockgroups
+                 */
+                avefreei = 0;
+                goto fallback;
+        }
+
+        return -1;
+}
+
+static int find_group_other(struct super_block *sb, struct inode *parent)
+{
+        int parent_group = EXT3_I(parent)->i_block_group;
+        int ngroups = EXT3_SB(sb)->s_groups_count;
+        struct ext3_group_desc *desc;
+        struct buffer_head *bh;
+        int group, i;
+
+        /*
+         * Try to place the inode in its parent directory
+         */
+        group = parent_group;
+        desc = ext3_get_group_desc (sb, group, &bh);
+        if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
+                        le16_to_cpu(desc->bg_free_blocks_count))
+                return group;
+
+        /*
+         * We're going to place this inode in a different blockgroup from its
+         * parent.  We want to cause files in a common directory to all land in
+         * the same blockgroup.  But we want files which are in a different
+         * directory which shares a blockgroup with our parent to land in a
+         * different blockgroup.
+         *
+         * So add our directory's i_ino into the starting point for the hash.
+         */
+        group = (group + parent->i_ino) % ngroups;
+
+        /*
+         * Use a quadratic hash to find a group with a free inode and some free
+         * blocks.
+         */
+        for (i = 1; i < ngroups; i <<= 1) {
+                group += i;
+                if (group >= ngroups)
+                        group -= ngroups;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
+                                le16_to_cpu(desc->bg_free_blocks_count))
+                        return group;
+        }
+
+        /*
+         * That failed: try linear search for a free inode, even if that group
+         * has no free blocks.
+         */
+        group = parent_group;
+        for (i = 0; i < ngroups; i++) {
+                if (++group >= ngroups)
+                        group = 0;
+                desc = ext3_get_group_desc (sb, group, &bh);
+                if (desc && le16_to_cpu(desc->bg_free_inodes_count))
+                        return group;
+        }
+
+        return -1;
+}
+
+/*
+ * There are two policies for allocating an inode.  If the new inode is
+ * a directory, then a forward search is made for a block group with both
+ * free space and a low directory-to-inode ratio; if that fails, then of
+ * the groups with above-average free space, that group with the fewest
+ * directories already is chosen.
+ *
+ * For other inodes, search forward from the parent directory's block
+ * group to find a free inode.
+ */
+struct inode *ext3_new_inode(handle_t *handle, struct inode * dir, int mode)
+{
+        struct super_block *sb;
+        struct buffer_head *bitmap_bh = NULL;
+        struct buffer_head *bh2;
+        int group;
+        unsigned long ino = 0;
+        struct inode * inode;
+        struct ext3_group_desc * gdp = NULL;
+        struct ext3_super_block * es;
+        struct ext3_inode_info *ei;
+        struct ext3_sb_info *sbi;
+        int err = 0;
+        struct inode *ret;
+        int i;
+
+        /* Cannot create files in a deleted directory */
+        if (!dir || !dir->i_nlink)
+                return ERR_PTR(-EPERM);
+
+        sb = dir->i_sb;
+        inode = new_inode(sb);
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+        ei = EXT3_I(inode);
+
+        sbi = EXT3_SB(sb);
+        es = sbi->s_es;
+        if (S_ISDIR(mode)) {
+                if (test_opt (sb, OLDALLOC))
+                        group = find_group_dir(sb, dir);
+                else
+                        group = find_group_orlov(sb, dir);
+        } else
+                group = find_group_other(sb, dir);
+
+        err = -ENOSPC;
+        if (group == -1)
+                goto out;
+
+        for (i = 0; i < sbi->s_groups_count; i++) {
+                err = -EIO;
+
+                gdp = ext3_get_group_desc(sb, group, &bh2);
+                if (!gdp)
+                        goto fail;
+
+                brelse(bitmap_bh);
+                bitmap_bh = read_inode_bitmap(sb, group);
+                if (!bitmap_bh)
+                        goto fail;
+
+                ino = 0;
+
+repeat_in_this_group:
+                ino = ext3_find_next_zero_bit((unsigned long *)
+                                bitmap_bh->b_data, EXT3_INODES_PER_GROUP(sb), ino);
+                if (ino < EXT3_INODES_PER_GROUP(sb)) {
+
+                        BUFFER_TRACE(bitmap_bh, "get_write_access");
+                        err = ext3_journal_get_write_access(handle, bitmap_bh);
+                        if (err)
+                                goto fail;
+
+                        if (!ext3_set_bit_atomic(sb_bgl_lock(sbi, group),
+                                                ino, bitmap_bh->b_data)) {
+                                /* we won it */
+                                BUFFER_TRACE(bitmap_bh,
+                                        "call ext3_journal_dirty_metadata");
+                                err = ext3_journal_dirty_metadata(handle,
+                                                                bitmap_bh);
+                                if (err)
+                                        goto fail;
+                                goto got;
+                        }
+                        /* we lost it */
+                        journal_release_buffer(handle, bitmap_bh);
+
+                        if (++ino < EXT3_INODES_PER_GROUP(sb))
+                                goto repeat_in_this_group;
+                }
+
+                /*
+                 * This case is possible in concurrent environment.  It is very
+                 * rare.  We cannot repeat the find_group_xxx() call because
+                 * that will simply return the same blockgroup, because the
+                 * group descriptor metadata has not yet been updated.
+                 * So we just go onto the next blockgroup.
+                 */
+                if (++group == sbi->s_groups_count)
+                        group = 0;
+        }
+        err = -ENOSPC;
+        goto out;
+
+got:
+        ino += group * EXT3_INODES_PER_GROUP(sb) + 1;
+        if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
+                ext3_error (sb, "ext3_new_inode",
+                            "reserved inode or inode > inodes count - "
+                            "block_group = %d, inode=%lu", group, ino);
+                err = -EIO;
+                goto fail;
+        }
+
+        BUFFER_TRACE(bh2, "get_write_access");
+        err = ext3_journal_get_write_access(handle, bh2);
+        if (err) goto fail;
+        spin_lock(sb_bgl_lock(sbi, group));
+        gdp->bg_free_inodes_count =
+                cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
+        if (S_ISDIR(mode)) {
+                gdp->bg_used_dirs_count =
+                        cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
+        }
+        spin_unlock(sb_bgl_lock(sbi, group));
+        BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
+        err = ext3_journal_dirty_metadata(handle, bh2);
+        if (err) goto fail;
+
+        percpu_counter_dec(&sbi->s_freeinodes_counter);
+        if (S_ISDIR(mode))
+                percpu_counter_inc(&sbi->s_dirs_counter);
+        sb->s_dirt = 1;
+
+        inode->i_uid = current->fsuid;
+        if (test_opt (sb, GRPID))
+                inode->i_gid = dir->i_gid;
+        else if (dir->i_mode & S_ISGID) {
+                inode->i_gid = dir->i_gid;
+                if (S_ISDIR(mode))
+                        mode |= S_ISGID;
+        } else
+                inode->i_gid = current->fsgid;
+        inode->i_mode = mode;
+
+        inode->i_ino = ino;
+        /* This is the optimal IO size (for stat), not the fs block size */
+        inode->i_blocks = 0;
+        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+
+        memset(ei->i_data, 0, sizeof(ei->i_data));
+        ei->i_dir_start_lookup = 0;
+        ei->i_disksize = 0;
+
+        ei->i_flags = EXT3_I(dir)->i_flags & ~EXT3_INDEX_FL;
+        if (S_ISLNK(mode))
+                ei->i_flags &= ~(EXT3_IMMUTABLE_FL|EXT3_APPEND_FL);
+        /* dirsync only applies to directories */
+        if (!S_ISDIR(mode))
+                ei->i_flags &= ~EXT3_DIRSYNC_FL;
+#ifdef EXT3_FRAGMENTS
+        ei->i_faddr = 0;
+        ei->i_frag_no = 0;
+        ei->i_frag_size = 0;
+#endif
+        ei->i_file_acl = 0;
+        ei->i_dir_acl = 0;
+        ei->i_dtime = 0;
+        ei->i_block_alloc_info = NULL;
+        ei->i_block_group = group;
+
+        ext3_set_inode_flags(inode);
+        if (IS_DIRSYNC(inode))
+                handle->h_sync = 1;
+        insert_inode_hash(inode);
+        spin_lock(&sbi->s_next_gen_lock);
+        inode->i_generation = sbi->s_next_generation++;
+        spin_unlock(&sbi->s_next_gen_lock);
+
+        ei->i_state = EXT3_STATE_NEW;
+        ei->i_extra_isize =
+                (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) ?
+                sizeof(struct ext3_inode) - EXT3_GOOD_OLD_INODE_SIZE : 0;
+
+        ret = inode;
+        if(DQUOT_ALLOC_INODE(inode)) {
+                err = -EDQUOT;
+                goto fail_drop;
+        }
+
+        err = ext3_init_acl(handle, inode, dir);
+        if (err)
+                goto fail_free_drop;
+
+        err = ext3_init_security(handle,inode, dir);
+        if (err)
+                goto fail_free_drop;
+
+        err = ext3_mark_inode_dirty(handle, inode);
+        if (err) {
+                ext3_std_error(sb, err);
+                goto fail_free_drop;
+        }
+
+        ext3_debug("allocating inode %lu\n", inode->i_ino);
+        goto really_out;
+fail:
+        ext3_std_error(sb, err);
+out:
+        iput(inode);
+        ret = ERR_PTR(err);
+really_out:
+        brelse(bitmap_bh);
+        return ret;
+
+fail_free_drop:
+        DQUOT_FREE_INODE(inode);
+
+fail_drop:
+        DQUOT_DROP(inode);
+        inode->i_flags |= S_NOQUOTA;
+        inode->i_nlink = 0;
+        iput(inode);
+        brelse(bitmap_bh);
+        return ERR_PTR(err);
+}
+
+/* Verify that we are loading a valid orphan from disk */
+struct inode *ext3_orphan_get(struct super_block *sb, unsigned long ino)
+{
+        unsigned long max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count);
+        unsigned long block_group;
+        int bit;
+        struct buffer_head *bitmap_bh = NULL;
+        struct inode *inode = NULL;
+
+        /* Error cases - e2fsck has already cleaned up for us */
+        if (ino > max_ino) {
+                ext3_warning(sb, __FUNCTION__,
+                             "bad orphan ino %lu!  e2fsck was run?", ino);
+                goto out;
+        }
+
+        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
+        bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
+        bitmap_bh = read_inode_bitmap(sb, block_group);
+        if (!bitmap_bh) {
+                ext3_warning(sb, __FUNCTION__,
+                             "inode bitmap error for orphan %lu", ino);
+                goto out;
+        }
+
+        /* Having the inode bit set should be a 100% indicator that this
+         * is a valid orphan (no e2fsck run on fs).  Orphans also include
+         * inodes that were being truncated, so we can't check i_nlink==0.
+         */
+        if (!ext3_test_bit(bit, bitmap_bh->b_data) ||
+                        !(inode = iget(sb, ino)) || is_bad_inode(inode) ||
+                        NEXT_ORPHAN(inode) > max_ino) {
+                ext3_warning(sb, __FUNCTION__,
+                             "bad orphan inode %lu!  e2fsck was run?", ino);
+                printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%llu) = %d\n",
+                       bit, (unsigned long long)bitmap_bh->b_blocknr,
+                       ext3_test_bit(bit, bitmap_bh->b_data));
+                printk(KERN_NOTICE "inode=%p\n", inode);
+                if (inode) {
+                        printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
+                               is_bad_inode(inode));
+                        printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
+                               NEXT_ORPHAN(inode));
+                        printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
+                }
+                /* Avoid freeing blocks if we got a bad deleted inode */
+                if (inode && inode->i_nlink == 0)
+                        inode->i_blocks = 0;
+                iput(inode);
+                inode = NULL;
+        }
+out:
+        brelse(bitmap_bh);
+        return inode;
+}
+
+unsigned long ext3_count_free_inodes (struct super_block * sb)
+{
+        unsigned long desc_count;
+        struct ext3_group_desc *gdp;
+        int i;
+#ifdef EXT3FS_DEBUG
+        struct ext3_super_block *es;
+        unsigned long bitmap_count, x;
+        struct buffer_head *bitmap_bh = NULL;
+
+        es = EXT3_SB(sb)->s_es;
+        desc_count = 0;
+        bitmap_count = 0;
+        gdp = NULL;
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+                brelse(bitmap_bh);
+                bitmap_bh = read_inode_bitmap(sb, i);
+                if (!bitmap_bh)
+                        continue;
+
+                x = ext3_count_free(bitmap_bh, EXT3_INODES_PER_GROUP(sb) / 8);
+                printk("group %d: stored = %d, counted = %lu\n",
+                        i, le16_to_cpu(gdp->bg_free_inodes_count), x);
+                bitmap_count += x;
+        }
+        brelse(bitmap_bh);
+        printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
+                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
+        return desc_count;
+#else
+        desc_count = 0;
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
+                cond_resched();
+        }
+        return desc_count;
+#endif
+}
+
+/* Called at mount-time, super-block is locked */
+unsigned long ext3_count_dirs (struct super_block * sb)
+{
+        unsigned long count = 0;
+        int i;
+
+        for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
+                struct ext3_group_desc *gdp = ext3_get_group_desc (sb, i, NULL);
+                if (!gdp)
+                        continue;
+                count += le16_to_cpu(gdp->bg_used_dirs_count);
+        }
+        return count;
+}
+