--- /dev/null
+Index: linux-2.6.16.21-0.8/fs/ext3/extents.c
+===================================================================
+--- /dev/null
++++ linux-2.6.16.21-0.8/fs/ext3/extents.c
+@@ -0,0 +1,2359 @@
++/*
++ * Copyright(c) 2003, 2004, 2005, Cluster File Systems, Inc, info@clusterfs.com
++ * Written by Alex Tomas <alex@clusterfs.com>
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public Licens
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
++ */
++
++/*
++ * Extents support for EXT3
++ *
++ * TODO:
++ * - ext3_ext_walk_space() sould not use ext3_ext_find_extent()
++ * - ext3_ext_calc_credits() could take 'mergable' into account
++ * - ext3*_error() should be used in some situations
++ * - find_goal() [to be tested and improved]
++ * - smart tree reduction
++ * - arch-independence
++ * common on-disk format for big/little-endian arch
++ */
++
++#include <linux/module.h>
++#include <linux/fs.h>
++#include <linux/time.h>
++#include <linux/ext3_jbd.h>
++#include <linux/jbd.h>
++#include <linux/smp_lock.h>
++#include <linux/highuid.h>
++#include <linux/pagemap.h>
++#include <linux/quotaops.h>
++#include <linux/string.h>
++#include <linux/slab.h>
++#include <linux/ext3_extents.h>
++#include <asm/uaccess.h>
++
++
++static inline int ext3_ext_check_header(struct ext3_extent_header *eh)
++{
++ if (eh->eh_magic != EXT3_EXT_MAGIC) {
++ printk(KERN_ERR "EXT3-fs: invalid magic = 0x%x\n",
++ (unsigned)eh->eh_magic);
++ return -EIO;
++ }
++ if (eh->eh_max == 0) {
++ printk(KERN_ERR "EXT3-fs: invalid eh_max = %u\n",
++ (unsigned)eh->eh_max);
++ return -EIO;
++ }
++ if (eh->eh_entries > eh->eh_max) {
++ printk(KERN_ERR "EXT3-fs: invalid eh_entries = %u\n",
++ (unsigned)eh->eh_entries);
++ return -EIO;
++ }
++ return 0;
++}
++
++static handle_t *ext3_ext_journal_restart(handle_t *handle, int needed)
++{
++ int err;
++
++ if (handle->h_buffer_credits > needed)
++ return handle;
++ if (!ext3_journal_extend(handle, needed))
++ return handle;
++ err = ext3_journal_restart(handle, needed);
++
++ return handle;
++}
++
++static int inline
++ext3_ext_get_access_for_root(handle_t *h, struct ext3_extents_tree *tree)
++{
++ if (tree->ops->get_write_access)
++ return tree->ops->get_write_access(h,tree->buffer);
++ else
++ return 0;
++}
++
++static int inline
++ext3_ext_mark_root_dirty(handle_t *h, struct ext3_extents_tree *tree)
++{
++ if (tree->ops->mark_buffer_dirty)
++ return tree->ops->mark_buffer_dirty(h,tree->buffer);
++ else
++ return 0;
++}
++
++/*
++ * could return:
++ * - EROFS
++ * - ENOMEM
++ */
++static int ext3_ext_get_access(handle_t *handle,
++ struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++ int err;
++
++ if (path->p_bh) {
++ /* path points to block */
++ err = ext3_journal_get_write_access(handle, path->p_bh);
++ } else {
++ /* path points to leaf/index in inode body */
++ err = ext3_ext_get_access_for_root(handle, tree);
++ }
++ return err;
++}
++
++/*
++ * could return:
++ * - EROFS
++ * - ENOMEM
++ * - EIO
++ */
++static int ext3_ext_dirty(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++ int err;
++ if (path->p_bh) {
++ /* path points to block */
++ err =ext3_journal_dirty_metadata(handle, path->p_bh);
++ } else {
++ /* path points to leaf/index in inode body */
++ err = ext3_ext_mark_root_dirty(handle, tree);
++ }
++ return err;
++}
++
++static int inline
++ext3_ext_new_block(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path, struct ext3_extent *ex,
++ int *err)
++{
++ int goal, depth, newblock;
++ struct inode *inode;
++
++ EXT_ASSERT(tree);
++ if (tree->ops->new_block)
++ return tree->ops->new_block(handle, tree, path, ex, err);
++
++ inode = tree->inode;
++ depth = EXT_DEPTH(tree);
++ if (path && depth > 0) {
++ goal = path[depth-1].p_block;
++ } else {
++ struct ext3_inode_info *ei = EXT3_I(inode);
++ unsigned long bg_start;
++ unsigned long colour;
++
++ bg_start = (ei->i_block_group *
++ EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
++ le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
++ colour = (current->pid % 16) *
++ (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
++ goal = bg_start + colour;
++ }
++
++ newblock = ext3_new_block(handle, inode, goal, err);
++ return newblock;
++}
++
++static inline void ext3_ext_tree_changed(struct ext3_extents_tree *tree)
++{
++ struct ext3_extent_header *neh = EXT_ROOT_HDR(tree);
++ neh->eh_generation = ((EXT_FLAGS(neh) & ~EXT_FLAGS_CLR_UNKNOWN) << 24) |
++ (EXT_HDR_GEN(neh) + 1);
++}
++
++static inline int ext3_ext_space_block(struct ext3_extents_tree *tree)
++{
++ int size;
++
++ size = (tree->inode->i_sb->s_blocksize -
++ sizeof(struct ext3_extent_header)) /
++ sizeof(struct ext3_extent);
++#ifdef AGRESSIVE_TEST
++ size = 6;
++#endif
++ return size;
++}
++
++static inline int ext3_ext_space_block_idx(struct ext3_extents_tree *tree)
++{
++ int size;
++
++ size = (tree->inode->i_sb->s_blocksize -
++ sizeof(struct ext3_extent_header)) /
++ sizeof(struct ext3_extent_idx);
++#ifdef AGRESSIVE_TEST
++ size = 5;
++#endif
++ return size;
++}
++
++static inline int ext3_ext_space_root(struct ext3_extents_tree *tree)
++{
++ int size;
++
++ size = (tree->buffer_len - sizeof(struct ext3_extent_header)) /
++ sizeof(struct ext3_extent);
++#ifdef AGRESSIVE_TEST
++ size = 3;
++#endif
++ return size;
++}
++
++static inline int ext3_ext_space_root_idx(struct ext3_extents_tree *tree)
++{
++ int size;
++
++ size = (tree->buffer_len - sizeof(struct ext3_extent_header)) /
++ sizeof(struct ext3_extent_idx);
++#ifdef AGRESSIVE_TEST
++ size = 4;
++#endif
++ return size;
++}
++
++static void ext3_ext_show_path(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++#ifdef EXT_DEBUG
++ int k, l = path->p_depth;
++
++ ext_debug(tree, "path:");
++ for (k = 0; k <= l; k++, path++) {
++ if (path->p_idx) {
++ ext_debug(tree, " %d->%d", path->p_idx->ei_block,
++ path->p_idx->ei_leaf);
++ } else if (path->p_ext) {
++ ext_debug(tree, " %d:%d:%d",
++ path->p_ext->ee_block,
++ path->p_ext->ee_len,
++ path->p_ext->ee_start);
++ } else
++ ext_debug(tree, " []");
++ }
++ ext_debug(tree, "\n");
++#endif
++}
++
++static void ext3_ext_show_leaf(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++#ifdef EXT_DEBUG
++ int depth = EXT_DEPTH(tree);
++ struct ext3_extent_header *eh;
++ struct ext3_extent *ex;
++ int i;
++
++ if (!path)
++ return;
++
++ eh = path[depth].p_hdr;
++ ex = EXT_FIRST_EXTENT(eh);
++
++ for (i = 0; i < eh->eh_entries; i++, ex++) {
++ ext_debug(tree, "%d:%d:%d ",
++ ex->ee_block, ex->ee_len, ex->ee_start);
++ }
++ ext_debug(tree, "\n");
++#endif
++}
++
++static void ext3_ext_drop_refs(struct ext3_ext_path *path)
++{
++ int depth = path->p_depth;
++ int i;
++
++ for (i = 0; i <= depth; i++, path++) {
++ if (path->p_bh) {
++ brelse(path->p_bh);
++ path->p_bh = NULL;
++ }
++ }
++}
++
++/*
++ * binary search for closest index by given block
++ */
++static inline void
++ext3_ext_binsearch_idx(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path, int block)
++{
++ struct ext3_extent_header *eh = path->p_hdr;
++ struct ext3_extent_idx *ix;
++ int l = 0, k, r;
++
++ EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
++ EXT_ASSERT(eh->eh_entries <= eh->eh_max);
++ EXT_ASSERT(eh->eh_entries > 0);
++
++ ext_debug(tree, "binsearch for %d(idx): ", block);
++
++ path->p_idx = ix = EXT_FIRST_INDEX(eh);
++
++ r = k = eh->eh_entries;
++ while (k > 1) {
++ k = (r - l) / 2;
++ if (block < ix[l + k].ei_block)
++ r -= k;
++ else
++ l += k;
++ ext_debug(tree, "%d:%d:%d ", k, l, r);
++ }
++
++ ix += l;
++ path->p_idx = ix;
++ ext_debug(tree," -> %d->%d ",path->p_idx->ei_block,path->p_idx->ei_leaf);
++
++ while (l++ < r) {
++ if (block < ix->ei_block)
++ break;
++ path->p_idx = ix++;
++ }
++ ext_debug(tree, " -> %d->%d\n", path->p_idx->ei_block,
++ path->p_idx->ei_leaf);
++
++#ifdef CHECK_BINSEARCH
++ {
++ struct ext3_extent_idx *chix;
++
++ chix = ix = EXT_FIRST_INDEX(eh);
++ for (k = 0; k < eh->eh_entries; k++, ix++) {
++ if (k != 0 && ix->ei_block <= ix[-1].ei_block) {
++ printk("k=%d, ix=0x%p, first=0x%p\n", k,
++ ix, EXT_FIRST_INDEX(eh));
++ printk("%u <= %u\n",
++ ix->ei_block,ix[-1].ei_block);
++ }
++ EXT_ASSERT(k == 0 || ix->ei_block > ix[-1].ei_block);
++ if (block < ix->ei_block)
++ break;
++ chix = ix;
++ }
++ EXT_ASSERT(chix == path->p_idx);
++ }
++#endif
++}
++
++/*
++ * binary search for closest extent by given block
++ */
++static inline void
++ext3_ext_binsearch(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path, int block)
++{
++ struct ext3_extent_header *eh = path->p_hdr;
++ struct ext3_extent *ex;
++ int l = 0, k, r;
++
++ EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
++ EXT_ASSERT(eh->eh_entries <= eh->eh_max);
++
++ if (eh->eh_entries == 0) {
++ /*
++ * this leaf is empty yet:
++ * we get such a leaf in split/add case
++ */
++ return;
++ }
++
++ ext_debug(tree, "binsearch for %d: ", block);
++
++ path->p_ext = ex = EXT_FIRST_EXTENT(eh);
++
++ r = k = eh->eh_entries;
++ while (k > 1) {
++ k = (r - l) / 2;
++ if (block < ex[l + k].ee_block)
++ r -= k;
++ else
++ l += k;
++ ext_debug(tree, "%d:%d:%d ", k, l, r);
++ }
++
++ ex += l;
++ path->p_ext = ex;
++ ext_debug(tree, " -> %d:%d:%d ", path->p_ext->ee_block,
++ path->p_ext->ee_start, path->p_ext->ee_len);
++
++ while (l++ < r) {
++ if (block < ex->ee_block)
++ break;
++ path->p_ext = ex++;
++ }
++ ext_debug(tree, " -> %d:%d:%d\n", path->p_ext->ee_block,
++ path->p_ext->ee_start, path->p_ext->ee_len);
++
++#ifdef CHECK_BINSEARCH
++ {
++ struct ext3_extent *chex;
++
++ chex = ex = EXT_FIRST_EXTENT(eh);
++ for (k = 0; k < eh->eh_entries; k++, ex++) {
++ EXT_ASSERT(k == 0 || ex->ee_block > ex[-1].ee_block);
++ if (block < ex->ee_block)
++ break;
++ chex = ex;
++ }
++ EXT_ASSERT(chex == path->p_ext);
++ }
++#endif
++}
++
++int ext3_extent_tree_init(handle_t *handle, struct ext3_extents_tree *tree)
++{
++ struct ext3_extent_header *eh;
++
++ BUG_ON(tree->buffer_len == 0);
++ ext3_ext_get_access_for_root(handle, tree);
++ eh = EXT_ROOT_HDR(tree);
++ eh->eh_depth = 0;
++ eh->eh_entries = 0;
++ eh->eh_magic = EXT3_EXT_MAGIC;
++ eh->eh_max = ext3_ext_space_root(tree);
++ ext3_ext_mark_root_dirty(handle, tree);
++ ext3_ext_invalidate_cache(tree);
++ return 0;
++}
++
++struct ext3_ext_path *
++ext3_ext_find_extent(struct ext3_extents_tree *tree, int block,
++ struct ext3_ext_path *path)
++{
++ struct ext3_extent_header *eh;
++ struct buffer_head *bh;
++ int depth, i, ppos = 0;
++
++ EXT_ASSERT(tree);
++ EXT_ASSERT(tree->inode);
++ EXT_ASSERT(tree->root);
++
++ eh = EXT_ROOT_HDR(tree);
++ EXT_ASSERT(eh);
++ if (ext3_ext_check_header(eh)) {
++ /* don't free previously allocated path
++ * -- caller should take care */
++ path = NULL;
++ goto err;
++ }
++
++ i = depth = EXT_DEPTH(tree);
++ EXT_ASSERT(eh->eh_max);
++ EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
++
++ /* account possible depth increase */
++ if (!path) {
++ path = kmalloc(sizeof(struct ext3_ext_path) * (depth + 2),
++ GFP_NOFS);
++ if (!path)
++ return ERR_PTR(-ENOMEM);
++ }
++ memset(path, 0, sizeof(struct ext3_ext_path) * (depth + 1));
++ path[0].p_hdr = eh;
++
++ /* walk through the tree */
++ while (i) {
++ ext_debug(tree, "depth %d: num %d, max %d\n",
++ ppos, eh->eh_entries, eh->eh_max);
++ ext3_ext_binsearch_idx(tree, path + ppos, block);
++ path[ppos].p_block = path[ppos].p_idx->ei_leaf;
++ path[ppos].p_depth = i;
++ path[ppos].p_ext = NULL;
++
++ bh = sb_bread(tree->inode->i_sb, path[ppos].p_block);
++ if (!bh)
++ goto err;
++
++ eh = EXT_BLOCK_HDR(bh);
++ ppos++;
++ EXT_ASSERT(ppos <= depth);
++ path[ppos].p_bh = bh;
++ path[ppos].p_hdr = eh;
++ i--;
++
++ if (ext3_ext_check_header(eh))
++ goto err;
++ }
++
++ path[ppos].p_depth = i;
++ path[ppos].p_hdr = eh;
++ path[ppos].p_ext = NULL;
++ path[ppos].p_idx = NULL;
++
++ if (ext3_ext_check_header(eh))
++ goto err;
++
++ /* find extent */
++ ext3_ext_binsearch(tree, path + ppos, block);
++
++ ext3_ext_show_path(tree, path);
++
++ return path;
++
++err:
++ printk(KERN_ERR "EXT3-fs: header is corrupted!\n");
++ if (path) {
++ ext3_ext_drop_refs(path);
++ kfree(path);
++ }
++ return ERR_PTR(-EIO);
++}
++
++/*
++ * insert new index [logical;ptr] into the block at cupr
++ * it check where to insert: before curp or after curp
++ */
++static int ext3_ext_insert_index(handle_t *handle,
++ struct ext3_extents_tree *tree,
++ struct ext3_ext_path *curp,
++ int logical, int ptr)
++{
++ struct ext3_extent_idx *ix;
++ int len, err;
++
++ if ((err = ext3_ext_get_access(handle, tree, curp)))
++ return err;
++
++ EXT_ASSERT(logical != curp->p_idx->ei_block);
++ len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
++ if (logical > curp->p_idx->ei_block) {
++ /* insert after */
++ if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
++ len = (len - 1) * sizeof(struct ext3_extent_idx);
++ len = len < 0 ? 0 : len;
++ ext_debug(tree, "insert new index %d after: %d. "
++ "move %d from 0x%p to 0x%p\n",
++ logical, ptr, len,
++ (curp->p_idx + 1), (curp->p_idx + 2));
++ memmove(curp->p_idx + 2, curp->p_idx + 1, len);
++ }
++ ix = curp->p_idx + 1;
++ } else {
++ /* insert before */
++ len = len * sizeof(struct ext3_extent_idx);
++ len = len < 0 ? 0 : len;
++ ext_debug(tree, "insert new index %d before: %d. "
++ "move %d from 0x%p to 0x%p\n",
++ logical, ptr, len,
++ curp->p_idx, (curp->p_idx + 1));
++ memmove(curp->p_idx + 1, curp->p_idx, len);
++ ix = curp->p_idx;
++ }
++
++ ix->ei_block = logical;
++ ix->ei_leaf = ptr;
++ ix->ei_leaf_hi = ix->ei_unused = 0;
++ curp->p_hdr->eh_entries++;
++
++ EXT_ASSERT(curp->p_hdr->eh_entries <= curp->p_hdr->eh_max);
++ EXT_ASSERT(ix <= EXT_LAST_INDEX(curp->p_hdr));
++
++ err = ext3_ext_dirty(handle, tree, curp);
++ ext3_std_error(tree->inode->i_sb, err);
++
++ return err;
++}
++
++/*
++ * routine inserts new subtree into the path, using free index entry
++ * at depth 'at:
++ * - allocates all needed blocks (new leaf and all intermediate index blocks)
++ * - makes decision where to split
++ * - moves remaining extens and index entries (right to the split point)
++ * into the newly allocated blocks
++ * - initialize subtree
++ */
++static int ext3_ext_split(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext, int at)
++{
++ struct buffer_head *bh = NULL;
++ int depth = EXT_DEPTH(tree);
++ struct ext3_extent_header *neh;
++ struct ext3_extent_idx *fidx;
++ struct ext3_extent *ex;
++ int i = at, k, m, a;
++ unsigned long newblock, oldblock, border;
++ int *ablocks = NULL; /* array of allocated blocks */
++ int err = 0;
++
++ /* make decision: where to split? */
++ /* FIXME: now desicion is simplest: at current extent */
++
++ /* if current leaf will be splitted, then we should use
++ * border from split point */
++ EXT_ASSERT(path[depth].p_ext <= EXT_MAX_EXTENT(path[depth].p_hdr));
++ if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
++ border = path[depth].p_ext[1].ee_block;
++ ext_debug(tree, "leaf will be splitted."
++ " next leaf starts at %d\n",
++ (int)border);
++ } else {
++ border = newext->ee_block;
++ ext_debug(tree, "leaf will be added."
++ " next leaf starts at %d\n",
++ (int)border);
++ }
++
++ /*
++ * if error occurs, then we break processing
++ * and turn filesystem read-only. so, index won't
++ * be inserted and tree will be in consistent
++ * state. next mount will repair buffers too
++ */
++
++ /*
++ * get array to track all allocated blocks
++ * we need this to handle errors and free blocks
++ * upon them
++ */
++ ablocks = kmalloc(sizeof(unsigned long) * depth, GFP_NOFS);
++ if (!ablocks)
++ return -ENOMEM;
++ memset(ablocks, 0, sizeof(unsigned long) * depth);
++
++ /* allocate all needed blocks */
++ ext_debug(tree, "allocate %d blocks for indexes/leaf\n", depth - at);
++ for (a = 0; a < depth - at; a++) {
++ newblock = ext3_ext_new_block(handle, tree, path, newext, &err);
++ if (newblock == 0)
++ goto cleanup;
++ ablocks[a] = newblock;
++ }
++
++ /* initialize new leaf */
++ newblock = ablocks[--a];
++ EXT_ASSERT(newblock);
++ bh = sb_getblk(tree->inode->i_sb, newblock);
++ if (!bh) {
++ err = -EIO;
++ goto cleanup;
++ }
++ lock_buffer(bh);
++
++ if ((err = ext3_journal_get_create_access(handle, bh)))
++ goto cleanup;
++
++ neh = EXT_BLOCK_HDR(bh);
++ neh->eh_entries = 0;
++ neh->eh_max = ext3_ext_space_block(tree);
++ neh->eh_magic = EXT3_EXT_MAGIC;
++ neh->eh_depth = 0;
++ ex = EXT_FIRST_EXTENT(neh);
++
++ /* move remain of path[depth] to the new leaf */
++ EXT_ASSERT(path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max);
++ /* start copy from next extent */
++ /* TODO: we could do it by single memmove */
++ m = 0;
++ path[depth].p_ext++;
++ while (path[depth].p_ext <=
++ EXT_MAX_EXTENT(path[depth].p_hdr)) {
++ ext_debug(tree, "move %d:%d:%d in new leaf %lu\n",
++ path[depth].p_ext->ee_block,
++ path[depth].p_ext->ee_start,
++ path[depth].p_ext->ee_len,
++ newblock);
++ memmove(ex++, path[depth].p_ext++, sizeof(struct ext3_extent));
++ neh->eh_entries++;
++ m++;
++ }
++ set_buffer_uptodate(bh);
++ unlock_buffer(bh);
++
++ if ((err = ext3_journal_dirty_metadata(handle, bh)))
++ goto cleanup;
++ brelse(bh);
++ bh = NULL;
++
++ /* correct old leaf */
++ if (m) {
++ if ((err = ext3_ext_get_access(handle, tree, path + depth)))
++ goto cleanup;
++ path[depth].p_hdr->eh_entries -= m;
++ if ((err = ext3_ext_dirty(handle, tree, path + depth)))
++ goto cleanup;
++
++ }
++
++ /* create intermediate indexes */
++ k = depth - at - 1;
++ EXT_ASSERT(k >= 0);
++ if (k)
++ ext_debug(tree, "create %d intermediate indices\n", k);
++ /* insert new index into current index block */
++ /* current depth stored in i var */
++ i = depth - 1;
++ while (k--) {
++ oldblock = newblock;
++ newblock = ablocks[--a];
++ bh = sb_getblk(tree->inode->i_sb, newblock);
++ if (!bh) {
++ err = -EIO;
++ goto cleanup;
++ }
++ lock_buffer(bh);
++
++ if ((err = ext3_journal_get_create_access(handle, bh)))
++ goto cleanup;
++
++ neh = EXT_BLOCK_HDR(bh);
++ neh->eh_entries = 1;
++ neh->eh_magic = EXT3_EXT_MAGIC;
++ neh->eh_max = ext3_ext_space_block_idx(tree);
++ neh->eh_depth = depth - i;
++ fidx = EXT_FIRST_INDEX(neh);
++ fidx->ei_block = border;
++ fidx->ei_leaf = oldblock;
++ fidx->ei_leaf_hi = fidx->ei_unused = 0;
++
++ ext_debug(tree, "int.index at %d (block %lu): %lu -> %lu\n",
++ i, newblock, border, oldblock);
++ /* copy indexes */
++ m = 0;
++ path[i].p_idx++;
++
++ ext_debug(tree, "cur 0x%p, last 0x%p\n", path[i].p_idx,
++ EXT_MAX_INDEX(path[i].p_hdr));
++ EXT_ASSERT(EXT_MAX_INDEX(path[i].p_hdr) ==
++ EXT_LAST_INDEX(path[i].p_hdr));
++ while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
++ ext_debug(tree, "%d: move %d:%d in new index %lu\n",
++ i, path[i].p_idx->ei_block,
++ path[i].p_idx->ei_leaf, newblock);
++ memmove(++fidx, path[i].p_idx++,
++ sizeof(struct ext3_extent_idx));
++ neh->eh_entries++;
++ EXT_ASSERT(neh->eh_entries <= neh->eh_max);
++ m++;
++ }
++ set_buffer_uptodate(bh);
++ unlock_buffer(bh);
++
++ if ((err = ext3_journal_dirty_metadata(handle, bh)))
++ goto cleanup;
++ brelse(bh);
++ bh = NULL;
++
++ /* correct old index */
++ if (m) {
++ err = ext3_ext_get_access(handle, tree, path + i);
++ if (err)
++ goto cleanup;
++ path[i].p_hdr->eh_entries -= m;
++ err = ext3_ext_dirty(handle, tree, path + i);
++ if (err)
++ goto cleanup;
++ }
++
++ i--;
++ }
++
++ /* insert new index */
++ if (!err)
++ err = ext3_ext_insert_index(handle, tree, path + at,
++ border, newblock);
++
++cleanup:
++ if (bh) {
++ if (buffer_locked(bh))
++ unlock_buffer(bh);
++ brelse(bh);
++ }
++
++ if (err) {
++ /* free all allocated blocks in error case */
++ for (i = 0; i < depth; i++) {
++ if (!ablocks[i])
++ continue;
++ ext3_free_blocks(handle, tree->inode, ablocks[i], 1);
++ }
++ }
++ kfree(ablocks);
++
++ return err;
++}
++
++/*
++ * routine implements tree growing procedure:
++ * - allocates new block
++ * - moves top-level data (index block or leaf) into the new block
++ * - initialize new top-level, creating index that points to the
++ * just created block
++ */
++static int ext3_ext_grow_indepth(handle_t *handle,
++ struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext)
++{
++ struct ext3_ext_path *curp = path;
++ struct ext3_extent_header *neh;
++ struct ext3_extent_idx *fidx;
++ struct buffer_head *bh;
++ unsigned long newblock;
++ int err = 0;
++
++ newblock = ext3_ext_new_block(handle, tree, path, newext, &err);
++ if (newblock == 0)
++ return err;
++
++ bh = sb_getblk(tree->inode->i_sb, newblock);
++ if (!bh) {
++ err = -EIO;
++ ext3_std_error(tree->inode->i_sb, err);
++ return err;
++ }
++ lock_buffer(bh);
++
++ if ((err = ext3_journal_get_create_access(handle, bh))) {
++ unlock_buffer(bh);
++ goto out;
++ }
++
++ /* move top-level index/leaf into new block */
++ memmove(bh->b_data, curp->p_hdr, tree->buffer_len);
++
++ /* set size of new block */
++ neh = EXT_BLOCK_HDR(bh);
++ /* old root could have indexes or leaves
++ * so calculate eh_max right way */
++ if (EXT_DEPTH(tree))
++ neh->eh_max = ext3_ext_space_block_idx(tree);
++ else
++ neh->eh_max = ext3_ext_space_block(tree);
++ neh->eh_magic = EXT3_EXT_MAGIC;
++ set_buffer_uptodate(bh);
++ unlock_buffer(bh);
++
++ if ((err = ext3_journal_dirty_metadata(handle, bh)))
++ goto out;
++
++ /* create index in new top-level index: num,max,pointer */
++ if ((err = ext3_ext_get_access(handle, tree, curp)))
++ goto out;
++
++ curp->p_hdr->eh_magic = EXT3_EXT_MAGIC;
++ curp->p_hdr->eh_max = ext3_ext_space_root_idx(tree);
++ curp->p_hdr->eh_entries = 1;
++ curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
++ /* FIXME: it works, but actually path[0] can be index */
++ curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
++ curp->p_idx->ei_leaf = newblock;
++ curp->p_idx->ei_leaf_hi = curp->p_idx->ei_unused = 0;
++
++ neh = EXT_ROOT_HDR(tree);
++ fidx = EXT_FIRST_INDEX(neh);
++ ext_debug(tree, "new root: num %d(%d), lblock %d, ptr %d\n",
++ neh->eh_entries, neh->eh_max, fidx->ei_block, fidx->ei_leaf);
++
++ neh->eh_depth = path->p_depth + 1;
++ err = ext3_ext_dirty(handle, tree, curp);
++out:
++ brelse(bh);
++
++ return err;
++}
++
++/*
++ * routine finds empty index and adds new leaf. if no free index found
++ * then it requests in-depth growing
++ */
++static int ext3_ext_create_new_leaf(handle_t *handle,
++ struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext)
++{
++ struct ext3_ext_path *curp;
++ int depth, i, err = 0;
++
++repeat:
++ i = depth = EXT_DEPTH(tree);
++
++ /* walk up to the tree and look for free index entry */
++ curp = path + depth;
++ while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
++ i--;
++ curp--;
++ }
++
++ /* we use already allocated block for index block
++ * so, subsequent data blocks should be contigoues */
++ if (EXT_HAS_FREE_INDEX(curp)) {
++ /* if we found index with free entry, then use that
++ * entry: create all needed subtree and add new leaf */
++ err = ext3_ext_split(handle, tree, path, newext, i);
++
++ /* refill path */
++ ext3_ext_drop_refs(path);
++ path = ext3_ext_find_extent(tree, newext->ee_block, path);
++ if (IS_ERR(path))
++ err = PTR_ERR(path);
++ } else {
++ /* tree is full, time to grow in depth */
++ err = ext3_ext_grow_indepth(handle, tree, path, newext);
++
++ /* refill path */
++ ext3_ext_drop_refs(path);
++ path = ext3_ext_find_extent(tree, newext->ee_block, path);
++ if (IS_ERR(path))
++ err = PTR_ERR(path);
++
++ /*
++ * only first (depth 0 -> 1) produces free space
++ * in all other cases we have to split growed tree
++ */
++ depth = EXT_DEPTH(tree);
++ if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
++ /* now we need split */
++ goto repeat;
++ }
++ }
++
++ if (err)
++ return err;
++
++ return 0;
++}
++
++/*
++ * returns allocated block in subsequent extent or EXT_MAX_BLOCK
++ * NOTE: it consider block number from index entry as
++ * allocated block. thus, index entries have to be consistent
++ * with leafs
++ */
++static unsigned long
++ext3_ext_next_allocated_block(struct ext3_ext_path *path)
++{
++ int depth;
++
++ EXT_ASSERT(path != NULL);
++ depth = path->p_depth;
++
++ if (depth == 0 && path->p_ext == NULL)
++ return EXT_MAX_BLOCK;
++
++ /* FIXME: what if index isn't full ?! */
++ while (depth >= 0) {
++ if (depth == path->p_depth) {
++ /* leaf */
++ if (path[depth].p_ext !=
++ EXT_LAST_EXTENT(path[depth].p_hdr))
++ return path[depth].p_ext[1].ee_block;
++ } else {
++ /* index */
++ if (path[depth].p_idx !=
++ EXT_LAST_INDEX(path[depth].p_hdr))
++ return path[depth].p_idx[1].ei_block;
++ }
++ depth--;
++ }
++
++ return EXT_MAX_BLOCK;
++}
++
++/*
++ * returns first allocated block from next leaf or EXT_MAX_BLOCK
++ */
++static unsigned ext3_ext_next_leaf_block(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++ int depth;
++
++ EXT_ASSERT(path != NULL);
++ depth = path->p_depth;
++
++ /* zero-tree has no leaf blocks at all */
++ if (depth == 0)
++ return EXT_MAX_BLOCK;
++
++ /* go to index block */
++ depth--;
++
++ while (depth >= 0) {
++ if (path[depth].p_idx !=
++ EXT_LAST_INDEX(path[depth].p_hdr))
++ return path[depth].p_idx[1].ei_block;
++ depth--;
++ }
++
++ return EXT_MAX_BLOCK;
++}
++
++/*
++ * if leaf gets modified and modified extent is first in the leaf
++ * then we have to correct all indexes above
++ * TODO: do we need to correct tree in all cases?
++ */
++int ext3_ext_correct_indexes(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++ struct ext3_extent_header *eh;
++ int depth = EXT_DEPTH(tree);
++ struct ext3_extent *ex;
++ unsigned long border;
++ int k, err = 0;
++
++ eh = path[depth].p_hdr;
++ ex = path[depth].p_ext;
++ EXT_ASSERT(ex);
++ EXT_ASSERT(eh);
++
++ if (depth == 0) {
++ /* there is no tree at all */
++ return 0;
++ }
++
++ if (ex != EXT_FIRST_EXTENT(eh)) {
++ /* we correct tree if first leaf got modified only */
++ return 0;
++ }
++
++ /*
++ * TODO: we need correction if border is smaller then current one
++ */
++ k = depth - 1;
++ border = path[depth].p_ext->ee_block;
++ if ((err = ext3_ext_get_access(handle, tree, path + k)))
++ return err;
++ path[k].p_idx->ei_block = border;
++ if ((err = ext3_ext_dirty(handle, tree, path + k)))
++ return err;
++
++ while (k--) {
++ /* change all left-side indexes */
++ if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
++ break;
++ if ((err = ext3_ext_get_access(handle, tree, path + k)))
++ break;
++ path[k].p_idx->ei_block = border;
++ if ((err = ext3_ext_dirty(handle, tree, path + k)))
++ break;
++ }
++
++ return err;
++}
++
++static int inline
++ext3_can_extents_be_merged(struct ext3_extents_tree *tree,
++ struct ext3_extent *ex1,
++ struct ext3_extent *ex2)
++{
++ if (ex1->ee_block + ex1->ee_len != ex2->ee_block)
++ return 0;
++
++#ifdef AGRESSIVE_TEST
++ if (ex1->ee_len >= 4)
++ return 0;
++#endif
++
++ if (!tree->ops->mergable)
++ return 1;
++
++ return tree->ops->mergable(ex1, ex2);
++}
++
++/*
++ * this routine tries to merge requsted extent into the existing
++ * extent or inserts requested extent as new one into the tree,
++ * creating new leaf in no-space case
++ */
++int ext3_ext_insert_extent(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext)
++{
++ struct ext3_extent_header * eh;
++ struct ext3_extent *ex, *fex;
++ struct ext3_extent *nearex; /* nearest extent */
++ struct ext3_ext_path *npath = NULL;
++ int depth, len, err, next;
++
++ EXT_ASSERT(newext->ee_len > 0);
++ depth = EXT_DEPTH(tree);
++ ex = path[depth].p_ext;
++ EXT_ASSERT(path[depth].p_hdr);
++
++ /* try to insert block into found extent and return */
++ if (ex && ext3_can_extents_be_merged(tree, ex, newext)) {
++ ext_debug(tree, "append %d block to %d:%d (from %d)\n",
++ newext->ee_len, ex->ee_block, ex->ee_len,
++ ex->ee_start);
++ if ((err = ext3_ext_get_access(handle, tree, path + depth)))
++ return err;
++ ex->ee_len += newext->ee_len;
++ eh = path[depth].p_hdr;
++ nearex = ex;
++ goto merge;
++ }
++
++repeat:
++ depth = EXT_DEPTH(tree);
++ eh = path[depth].p_hdr;
++ if (eh->eh_entries < eh->eh_max)
++ goto has_space;
++
++ /* probably next leaf has space for us? */
++ fex = EXT_LAST_EXTENT(eh);
++ next = ext3_ext_next_leaf_block(tree, path);
++ if (newext->ee_block > fex->ee_block && next != EXT_MAX_BLOCK) {
++ ext_debug(tree, "next leaf block - %d\n", next);
++ EXT_ASSERT(!npath);
++ npath = ext3_ext_find_extent(tree, next, NULL);
++ if (IS_ERR(npath))
++ return PTR_ERR(npath);
++ EXT_ASSERT(npath->p_depth == path->p_depth);
++ eh = npath[depth].p_hdr;
++ if (eh->eh_entries < eh->eh_max) {
++ ext_debug(tree, "next leaf isnt full(%d)\n",
++ eh->eh_entries);
++ path = npath;
++ goto repeat;
++ }
++ ext_debug(tree, "next leaf hasno free space(%d,%d)\n",
++ eh->eh_entries, eh->eh_max);
++ }
++
++ /*
++ * there is no free space in found leaf
++ * we're gonna add new leaf in the tree
++ */
++ err = ext3_ext_create_new_leaf(handle, tree, path, newext);
++ if (err)
++ goto cleanup;
++ depth = EXT_DEPTH(tree);
++ eh = path[depth].p_hdr;
++
++has_space:
++ nearex = path[depth].p_ext;
++
++ if ((err = ext3_ext_get_access(handle, tree, path + depth)))
++ goto cleanup;
++
++ if (!nearex) {
++ /* there is no extent in this leaf, create first one */
++ ext_debug(tree, "first extent in the leaf: %d:%d:%d\n",
++ newext->ee_block, newext->ee_start,
++ newext->ee_len);
++ path[depth].p_ext = EXT_FIRST_EXTENT(eh);
++ } else if (newext->ee_block > nearex->ee_block) {
++ EXT_ASSERT(newext->ee_block != nearex->ee_block);
++ if (nearex != EXT_LAST_EXTENT(eh)) {
++ len = EXT_MAX_EXTENT(eh) - nearex;
++ len = (len - 1) * sizeof(struct ext3_extent);
++ len = len < 0 ? 0 : len;
++ ext_debug(tree, "insert %d:%d:%d after: nearest 0x%p, "
++ "move %d from 0x%p to 0x%p\n",
++ newext->ee_block, newext->ee_start,
++ newext->ee_len,
++ nearex, len, nearex + 1, nearex + 2);
++ memmove(nearex + 2, nearex + 1, len);
++ }
++ path[depth].p_ext = nearex + 1;
++ } else {
++ EXT_ASSERT(newext->ee_block != nearex->ee_block);
++ len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext3_extent);
++ len = len < 0 ? 0 : len;
++ ext_debug(tree, "insert %d:%d:%d before: nearest 0x%p, "
++ "move %d from 0x%p to 0x%p\n",
++ newext->ee_block, newext->ee_start, newext->ee_len,
++ nearex, len, nearex + 1, nearex + 2);
++ memmove(nearex + 1, nearex, len);
++ path[depth].p_ext = nearex;
++ }
++
++ eh->eh_entries++;
++ nearex = path[depth].p_ext;
++ nearex->ee_block = newext->ee_block;
++ nearex->ee_start = newext->ee_start;
++ nearex->ee_len = newext->ee_len;
++ /* FIXME: support for large fs */
++ nearex->ee_start_hi = 0;
++
++merge:
++ /* try to merge extents to the right */
++ while (nearex < EXT_LAST_EXTENT(eh)) {
++ if (!ext3_can_extents_be_merged(tree, nearex, nearex + 1))
++ break;
++ /* merge with next extent! */
++ nearex->ee_len += nearex[1].ee_len;
++ if (nearex + 1 < EXT_LAST_EXTENT(eh)) {
++ len = (EXT_LAST_EXTENT(eh) - nearex - 1) *
++ sizeof(struct ext3_extent);
++ memmove(nearex + 1, nearex + 2, len);
++ }
++ eh->eh_entries--;
++ EXT_ASSERT(eh->eh_entries > 0);
++ }
++
++ /* try to merge extents to the left */
++
++ /* time to correct all indexes above */
++ err = ext3_ext_correct_indexes(handle, tree, path);
++ if (err)
++ goto cleanup;
++
++ err = ext3_ext_dirty(handle, tree, path + depth);
++
++cleanup:
++ if (npath) {
++ ext3_ext_drop_refs(npath);
++ kfree(npath);
++ }
++ ext3_ext_tree_changed(tree);
++ ext3_ext_invalidate_cache(tree);
++ return err;
++}
++
++int ext3_ext_walk_space(struct ext3_extents_tree *tree, unsigned long block,
++ unsigned long num, ext_prepare_callback func)
++{
++ struct ext3_ext_path *path = NULL;
++ struct ext3_ext_cache cbex;
++ struct ext3_extent *ex;
++ unsigned long next, start = 0, end = 0;
++ unsigned long last = block + num;
++ int depth, exists, err = 0;
++
++ EXT_ASSERT(tree);
++ EXT_ASSERT(func);
++ EXT_ASSERT(tree->inode);
++ EXT_ASSERT(tree->root);
++
++ while (block < last && block != EXT_MAX_BLOCK) {
++ num = last - block;
++ /* find extent for this block */
++ path = ext3_ext_find_extent(tree, block, path);
++ if (IS_ERR(path)) {
++ err = PTR_ERR(path);
++ path = NULL;
++ break;
++ }
++
++ depth = EXT_DEPTH(tree);
++ EXT_ASSERT(path[depth].p_hdr);
++ ex = path[depth].p_ext;
++ next = ext3_ext_next_allocated_block(path);
++
++ exists = 0;
++ if (!ex) {
++ /* there is no extent yet, so try to allocate
++ * all requested space */
++ start = block;
++ end = block + num;
++ } else if (ex->ee_block > block) {
++ /* need to allocate space before found extent */
++ start = block;
++ end = ex->ee_block;
++ if (block + num < end)
++ end = block + num;
++ } else if (block >= ex->ee_block + ex->ee_len) {
++ /* need to allocate space after found extent */
++ start = block;
++ end = block + num;
++ if (end >= next)
++ end = next;
++ } else if (block >= ex->ee_block) {
++ /*
++ * some part of requested space is covered
++ * by found extent
++ */
++ start = block;
++ end = ex->ee_block + ex->ee_len;
++ if (block + num < end)
++ end = block + num;
++ exists = 1;
++ } else {
++ BUG();
++ }
++ EXT_ASSERT(end > start);
++
++ if (!exists) {
++ cbex.ec_block = start;
++ cbex.ec_len = end - start;
++ cbex.ec_start = 0;
++ cbex.ec_type = EXT3_EXT_CACHE_GAP;
++ } else {
++ cbex.ec_block = ex->ee_block;
++ cbex.ec_len = ex->ee_len;
++ cbex.ec_start = ex->ee_start;
++ cbex.ec_type = EXT3_EXT_CACHE_EXTENT;
++ }
++
++ EXT_ASSERT(cbex.ec_len > 0);
++ EXT_ASSERT(path[depth].p_hdr);
++ err = func(tree, path, &cbex);
++ ext3_ext_drop_refs(path);
++
++ if (err < 0)
++ break;
++ if (err == EXT_REPEAT)
++ continue;
++ else if (err == EXT_BREAK) {
++ err = 0;
++ break;
++ }
++
++ if (EXT_DEPTH(tree) != depth) {
++ /* depth was changed. we have to realloc path */
++ kfree(path);
++ path = NULL;
++ }
++
++ block = cbex.ec_block + cbex.ec_len;
++ }
++
++ if (path) {
++ ext3_ext_drop_refs(path);
++ kfree(path);
++ }
++
++ return err;
++}
++
++static inline void
++ext3_ext_put_in_cache(struct ext3_extents_tree *tree, __u32 block,
++ __u32 len, __u32 start, int type)
++{
++ EXT_ASSERT(len > 0);
++ if (tree->cex) {
++ tree->cex->ec_type = type;
++ tree->cex->ec_block = block;
++ tree->cex->ec_len = len;
++ tree->cex->ec_start = start;
++ }
++}
++
++/*
++ * this routine calculate boundaries of the gap requested block fits into
++ * and cache this gap
++ */
++static inline void
++ext3_ext_put_gap_in_cache(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ unsigned long block)
++{
++ int depth = EXT_DEPTH(tree);
++ unsigned long lblock, len;
++ struct ext3_extent *ex;
++
++ if (!tree->cex)
++ return;
++
++ ex = path[depth].p_ext;
++ if (ex == NULL) {
++ /* there is no extent yet, so gap is [0;-] */
++ lblock = 0;
++ len = EXT_MAX_BLOCK;
++ ext_debug(tree, "cache gap(whole file):");
++ } else if (block < ex->ee_block) {
++ lblock = block;
++ len = ex->ee_block - block;
++ ext_debug(tree, "cache gap(before): %lu [%lu:%lu]",
++ (unsigned long) block,
++ (unsigned long) ex->ee_block,
++ (unsigned long) ex->ee_len);
++ } else if (block >= ex->ee_block + ex->ee_len) {
++ lblock = ex->ee_block + ex->ee_len;
++ len = ext3_ext_next_allocated_block(path);
++ ext_debug(tree, "cache gap(after): [%lu:%lu] %lu",
++ (unsigned long) ex->ee_block,
++ (unsigned long) ex->ee_len,
++ (unsigned long) block);
++ EXT_ASSERT(len > lblock);
++ len = len - lblock;
++ } else {
++ lblock = len = 0;
++ BUG();
++ }
++
++ ext_debug(tree, " -> %lu:%lu\n", (unsigned long) lblock, len);
++ ext3_ext_put_in_cache(tree, lblock, len, 0, EXT3_EXT_CACHE_GAP);
++}
++
++static inline int
++ext3_ext_in_cache(struct ext3_extents_tree *tree, unsigned long block,
++ struct ext3_extent *ex)
++{
++ struct ext3_ext_cache *cex = tree->cex;
++
++ /* is there cache storage at all? */
++ if (!cex)
++ return EXT3_EXT_CACHE_NO;
++
++ /* has cache valid data? */
++ if (cex->ec_type == EXT3_EXT_CACHE_NO)
++ return EXT3_EXT_CACHE_NO;
++
++ EXT_ASSERT(cex->ec_type == EXT3_EXT_CACHE_GAP ||
++ cex->ec_type == EXT3_EXT_CACHE_EXTENT);
++ if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
++ ex->ee_block = cex->ec_block;
++ ex->ee_start = cex->ec_start;
++ ex->ee_start_hi = 0;
++ ex->ee_len = cex->ec_len;
++ ext_debug(tree, "%lu cached by %lu:%lu:%lu\n",
++ (unsigned long) block,
++ (unsigned long) ex->ee_block,
++ (unsigned long) ex->ee_len,
++ (unsigned long) ex->ee_start);
++ return cex->ec_type;
++ }
++
++ /* not in cache */
++ return EXT3_EXT_CACHE_NO;
++}
++
++/*
++ * routine removes index from the index block
++ * it's used in truncate case only. thus all requests are for
++ * last index in the block only
++ */
++int ext3_ext_rm_idx(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++ struct buffer_head *bh;
++ int err;
++
++ /* free index block */
++ path--;
++ EXT_ASSERT(path->p_hdr->eh_entries);
++ if ((err = ext3_ext_get_access(handle, tree, path)))
++ return err;
++ path->p_hdr->eh_entries--;
++ if ((err = ext3_ext_dirty(handle, tree, path)))
++ return err;
++ ext_debug(tree, "index is empty, remove it, free block %d\n",
++ path->p_idx->ei_leaf);
++ bh = sb_find_get_block(tree->inode->i_sb, path->p_idx->ei_leaf);
++ ext3_forget(handle, 1, tree->inode, bh, path->p_idx->ei_leaf);
++ ext3_free_blocks(handle, tree->inode, path->p_idx->ei_leaf, 1);
++ return err;
++}
++
++int ext3_ext_calc_credits_for_insert(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path)
++{
++ int depth = EXT_DEPTH(tree);
++ int needed;
++
++ if (path) {
++ /* probably there is space in leaf? */
++ if (path[depth].p_hdr->eh_entries < path[depth].p_hdr->eh_max)
++ return 1;
++ }
++
++ /*
++ * the worste case we're expecting is creation of the
++ * new root (growing in depth) with index splitting
++ * for splitting we have to consider depth + 1 because
++ * previous growing could increase it
++ */
++ depth = depth + 1;
++
++ /*
++ * growing in depth:
++ * block allocation + new root + old root
++ */
++ needed = EXT3_ALLOC_NEEDED + 2;
++
++ /* index split. we may need:
++ * allocate intermediate indexes and new leaf
++ * change two blocks at each level, but root
++ * modify root block (inode)
++ */
++ needed += (depth * EXT3_ALLOC_NEEDED) + (2 * depth) + 1;
++
++ return needed;
++}
++
++static int
++ext3_ext_split_for_rm(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path, unsigned long start,
++ unsigned long end)
++{
++ struct ext3_extent *ex, tex;
++ struct ext3_ext_path *npath;
++ int depth, creds, err;
++
++ depth = EXT_DEPTH(tree);
++ ex = path[depth].p_ext;
++ EXT_ASSERT(ex);
++ EXT_ASSERT(end < ex->ee_block + ex->ee_len - 1);
++ EXT_ASSERT(ex->ee_block < start);
++
++ /* calculate tail extent */
++ tex.ee_block = end + 1;
++ EXT_ASSERT(tex.ee_block < ex->ee_block + ex->ee_len);
++ tex.ee_len = ex->ee_block + ex->ee_len - tex.ee_block;
++
++ creds = ext3_ext_calc_credits_for_insert(tree, path);
++ handle = ext3_ext_journal_restart(handle, creds);
++ if (IS_ERR(handle))
++ return PTR_ERR(handle);
++
++ /* calculate head extent. use primary extent */
++ err = ext3_ext_get_access(handle, tree, path + depth);
++ if (err)
++ return err;
++ ex->ee_len = start - ex->ee_block;
++ err = ext3_ext_dirty(handle, tree, path + depth);
++ if (err)
++ return err;
++
++ /* FIXME: some callback to free underlying resource
++ * and correct ee_start? */
++ ext_debug(tree, "split extent: head %u:%u, tail %u:%u\n",
++ ex->ee_block, ex->ee_len, tex.ee_block, tex.ee_len);
++
++ npath = ext3_ext_find_extent(tree, ex->ee_block, NULL);
++ if (IS_ERR(npath))
++ return PTR_ERR(npath);
++ depth = EXT_DEPTH(tree);
++ EXT_ASSERT(npath[depth].p_ext->ee_block == ex->ee_block);
++ EXT_ASSERT(npath[depth].p_ext->ee_len == ex->ee_len);
++
++ err = ext3_ext_insert_extent(handle, tree, npath, &tex);
++ ext3_ext_drop_refs(npath);
++ kfree(npath);
++
++ return err;
++}
++
++static int
++ext3_ext_rm_leaf(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path, unsigned long start,
++ unsigned long end)
++{
++ struct ext3_extent *ex, *fu = NULL, *lu, *le;
++ int err = 0, correct_index = 0;
++ int depth = EXT_DEPTH(tree), credits;
++ struct ext3_extent_header *eh;
++ unsigned a, b, block, num;
++
++ ext_debug(tree, "remove [%lu:%lu] in leaf\n", start, end);
++ if (!path[depth].p_hdr)
++ path[depth].p_hdr = EXT_BLOCK_HDR(path[depth].p_bh);
++ eh = path[depth].p_hdr;
++ EXT_ASSERT(eh);
++ EXT_ASSERT(eh->eh_entries <= eh->eh_max);
++ EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
++
++ /* find where to start removing */
++ le = ex = EXT_LAST_EXTENT(eh);
++ while (ex != EXT_FIRST_EXTENT(eh)) {
++ if (ex->ee_block <= end)
++ break;
++ ex--;
++ }
++
++ if (start > ex->ee_block && end < ex->ee_block + ex->ee_len - 1) {
++ /* removal of internal part of the extent requested
++ * tail and head must be placed in different extent
++ * so, we have to insert one more extent */
++ path[depth].p_ext = ex;
++ return ext3_ext_split_for_rm(handle, tree, path, start, end);
++ }
++
++ lu = ex;
++ while (ex >= EXT_FIRST_EXTENT(eh) && ex->ee_block + ex->ee_len > start) {
++ ext_debug(tree, "remove ext %u:%u\n", ex->ee_block, ex->ee_len);
++ path[depth].p_ext = ex;
++
++ a = ex->ee_block > start ? ex->ee_block : start;
++ b = ex->ee_block + ex->ee_len - 1 < end ?
++ ex->ee_block + ex->ee_len - 1 : end;
++
++ ext_debug(tree, " border %u:%u\n", a, b);
++
++ if (a != ex->ee_block && b != ex->ee_block + ex->ee_len - 1) {
++ block = 0;
++ num = 0;
++ BUG();
++ } else if (a != ex->ee_block) {
++ /* remove tail of the extent */
++ block = ex->ee_block;
++ num = a - block;
++ } else if (b != ex->ee_block + ex->ee_len - 1) {
++ /* remove head of the extent */
++ block = a;
++ num = b - a;
++ } else {
++ /* remove whole extent: excelent! */
++ block = ex->ee_block;
++ num = 0;
++ EXT_ASSERT(a == ex->ee_block &&
++ b == ex->ee_block + ex->ee_len - 1);
++ }
++
++ if (ex == EXT_FIRST_EXTENT(eh))
++ correct_index = 1;
++
++ credits = 1;
++ if (correct_index)
++ credits += (EXT_DEPTH(tree) * EXT3_ALLOC_NEEDED) + 1;
++ if (tree->ops->remove_extent_credits)
++ credits+=tree->ops->remove_extent_credits(tree,ex,a,b);
++
++ handle = ext3_ext_journal_restart(handle, credits);
++ if (IS_ERR(handle)) {
++ err = PTR_ERR(handle);
++ goto out;
++ }
++
++ err = ext3_ext_get_access(handle, tree, path + depth);
++ if (err)
++ goto out;
++
++ if (tree->ops->remove_extent)
++ err = tree->ops->remove_extent(tree, ex, a, b);
++ if (err)
++ goto out;
++
++ if (num == 0) {
++ /* this extent is removed entirely mark slot unused */
++ ex->ee_start = ex->ee_start_hi = 0;
++ eh->eh_entries--;
++ fu = ex;
++ }
++
++ ex->ee_block = block;
++ ex->ee_len = num;
++
++ err = ext3_ext_dirty(handle, tree, path + depth);
++ if (err)
++ goto out;
++
++ ext_debug(tree, "new extent: %u:%u:%u\n",
++ ex->ee_block, ex->ee_len, ex->ee_start);
++ ex--;
++ }
++
++ if (fu) {
++ /* reuse unused slots */
++ while (lu < le) {
++ if (lu->ee_start) {
++ *fu = *lu;
++ lu->ee_start = lu->ee_start_hi = 0;
++ fu++;
++ }
++ lu++;
++ }
++ }
++
++ if (correct_index && eh->eh_entries)
++ err = ext3_ext_correct_indexes(handle, tree, path);
++
++ /* if this leaf is free, then we should
++ * remove it from index block above */
++ if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
++ err = ext3_ext_rm_idx(handle, tree, path + depth);
++
++out:
++ return err;
++}
++
++
++static struct ext3_extent_idx *
++ext3_ext_last_covered(struct ext3_extent_header *hdr, unsigned long block)
++{
++ struct ext3_extent_idx *ix;
++
++ ix = EXT_LAST_INDEX(hdr);
++ while (ix != EXT_FIRST_INDEX(hdr)) {
++ if (ix->ei_block <= block)
++ break;
++ ix--;
++ }
++ return ix;
++}
++
++/*
++ * returns 1 if current index have to be freed (even partial)
++ */
++static int inline
++ext3_ext_more_to_rm(struct ext3_ext_path *path)
++{
++ EXT_ASSERT(path->p_idx);
++
++ if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
++ return 0;
++
++ /*
++ * if truncate on deeper level happened it it wasn't partial
++ * so we have to consider current index for truncation
++ */
++ if (path->p_hdr->eh_entries == path->p_block)
++ return 0;
++ return 1;
++}
++
++int ext3_ext_remove_space(struct ext3_extents_tree *tree,
++ unsigned long start, unsigned long end)
++{
++ struct inode *inode = tree->inode;
++ struct super_block *sb = inode->i_sb;
++ int depth = EXT_DEPTH(tree);
++ struct ext3_ext_path *path;
++ handle_t *handle;
++ int i = 0, err = 0;
++
++ ext_debug(tree, "space to be removed: %lu:%lu\n", start, end);
++
++ /* probably first extent we're gonna free will be last in block */
++ handle = ext3_journal_start(inode, depth + 1);
++ if (IS_ERR(handle))
++ return PTR_ERR(handle);
++
++ ext3_ext_invalidate_cache(tree);
++
++ /*
++ * we start scanning from right side freeing all the blocks
++ * after i_size and walking into the deep
++ */
++ path = kmalloc(sizeof(struct ext3_ext_path) * (depth + 1), GFP_KERNEL);
++ if (IS_ERR(path)) {
++ ext3_error(sb, __FUNCTION__, "Can't allocate path array");
++ ext3_journal_stop(handle);
++ return -ENOMEM;
++ }
++ memset(path, 0, sizeof(struct ext3_ext_path) * (depth + 1));
++ path[i].p_hdr = EXT_ROOT_HDR(tree);
++
++ while (i >= 0 && err == 0) {
++ if (i == depth) {
++ /* this is leaf block */
++ err = ext3_ext_rm_leaf(handle, tree, path, start, end);
++ /* root level have p_bh == NULL, brelse() eats this */
++ brelse(path[i].p_bh);
++ i--;
++ continue;
++ }
++
++ /* this is index block */
++ if (!path[i].p_hdr) {
++ ext_debug(tree, "initialize header\n");
++ path[i].p_hdr = EXT_BLOCK_HDR(path[i].p_bh);
++ }
++
++ EXT_ASSERT(path[i].p_hdr->eh_entries <= path[i].p_hdr->eh_max);
++ EXT_ASSERT(path[i].p_hdr->eh_magic == EXT3_EXT_MAGIC);
++
++ if (!path[i].p_idx) {
++ /* this level hasn't touched yet */
++ path[i].p_idx =
++ ext3_ext_last_covered(path[i].p_hdr, end);
++ path[i].p_block = path[i].p_hdr->eh_entries + 1;
++ ext_debug(tree, "init index ptr: hdr 0x%p, num %d\n",
++ path[i].p_hdr, path[i].p_hdr->eh_entries);
++ } else {
++ /* we've already was here, see at next index */
++ path[i].p_idx--;
++ }
++
++ ext_debug(tree, "level %d - index, first 0x%p, cur 0x%p\n",
++ i, EXT_FIRST_INDEX(path[i].p_hdr),
++ path[i].p_idx);
++ if (ext3_ext_more_to_rm(path + i)) {
++ /* go to the next level */
++ ext_debug(tree, "move to level %d (block %d)\n",
++ i + 1, path[i].p_idx->ei_leaf);
++ memset(path + i + 1, 0, sizeof(*path));
++ path[i+1].p_bh = sb_bread(sb, path[i].p_idx->ei_leaf);
++ if (!path[i+1].p_bh) {
++ /* should we reset i_size? */
++ err = -EIO;
++ break;
++ }
++ /* put actual number of indexes to know is this
++ * number got changed at the next iteration */
++ path[i].p_block = path[i].p_hdr->eh_entries;
++ i++;
++ } else {
++ /* we finish processing this index, go up */
++ if (path[i].p_hdr->eh_entries == 0 && i > 0) {
++ /* index is empty, remove it
++ * handle must be already prepared by the
++ * truncatei_leaf() */
++ err = ext3_ext_rm_idx(handle, tree, path + i);
++ }
++ /* root level have p_bh == NULL, brelse() eats this */
++ brelse(path[i].p_bh);
++ i--;
++ ext_debug(tree, "return to level %d\n", i);
++ }
++ }
++
++ /* TODO: flexible tree reduction should be here */
++ if (path->p_hdr->eh_entries == 0) {
++ /*
++ * truncate to zero freed all the tree
++ * so, we need to correct eh_depth
++ */
++ err = ext3_ext_get_access(handle, tree, path);
++ if (err == 0) {
++ EXT_ROOT_HDR(tree)->eh_depth = 0;
++ EXT_ROOT_HDR(tree)->eh_max = ext3_ext_space_root(tree);
++ err = ext3_ext_dirty(handle, tree, path);
++ }
++ }
++ ext3_ext_tree_changed(tree);
++
++ kfree(path);
++ ext3_journal_stop(handle);
++
++ return err;
++}
++
++int ext3_ext_calc_metadata_amount(struct ext3_extents_tree *tree, int blocks)
++{
++ int lcap, icap, rcap, leafs, idxs, num;
++
++ rcap = ext3_ext_space_root(tree);
++ if (blocks <= rcap) {
++ /* all extents fit to the root */
++ return 0;
++ }
++
++ rcap = ext3_ext_space_root_idx(tree);
++ lcap = ext3_ext_space_block(tree);
++ icap = ext3_ext_space_block_idx(tree);
++
++ num = leafs = (blocks + lcap - 1) / lcap;
++ if (leafs <= rcap) {
++ /* all pointers to leafs fit to the root */
++ return leafs;
++ }
++
++ /* ok. we need separate index block(s) to link all leaf blocks */
++ idxs = (leafs + icap - 1) / icap;
++ do {
++ num += idxs;
++ idxs = (idxs + icap - 1) / icap;
++ } while (idxs > rcap);
++
++ return num;
++}
++
++/*
++ * called at mount time
++ */
++void ext3_ext_init(struct super_block *sb)
++{
++ /*
++ * possible initialization would be here
++ */
++
++ if (test_opt(sb, EXTENTS)) {
++ printk("EXT3-fs: file extents enabled");
++#ifdef AGRESSIVE_TEST
++ printk(", agressive tests");
++#endif
++#ifdef CHECK_BINSEARCH
++ printk(", check binsearch");
++#endif
++ printk("\n");
++ }
++}
++
++/*
++ * called at umount time
++ */
++void ext3_ext_release(struct super_block *sb)
++{
++}
++
++/************************************************************************
++ * VFS related routines
++ ************************************************************************/
++
++static int ext3_get_inode_write_access(handle_t *handle, void *buffer)
++{
++ /* we use in-core data, not bh */
++ return 0;
++}
++
++static int ext3_mark_buffer_dirty(handle_t *handle, void *buffer)
++{
++ struct inode *inode = buffer;
++ return ext3_mark_inode_dirty(handle, inode);
++}
++
++static int ext3_ext_mergable(struct ext3_extent *ex1,
++ struct ext3_extent *ex2)
++{
++ /* FIXME: support for large fs */
++ if (ex1->ee_start + ex1->ee_len == ex2->ee_start)
++ return 1;
++ return 0;
++}
++
++static int
++ext3_remove_blocks_credits(struct ext3_extents_tree *tree,
++ struct ext3_extent *ex,
++ unsigned long from, unsigned long to)
++{
++ int needed;
++
++ /* at present, extent can't cross block group */;
++ needed = 4; /* bitmap + group desc + sb + inode */
++
++#ifdef CONFIG_QUOTA
++ needed += 2 * EXT3_SINGLEDATA_TRANS_BLOCKS;
++#endif
++ return needed;
++}
++
++static int
++ext3_remove_blocks(struct ext3_extents_tree *tree,
++ struct ext3_extent *ex,
++ unsigned long from, unsigned long to)
++{
++ int needed = ext3_remove_blocks_credits(tree, ex, from, to);
++ handle_t *handle = ext3_journal_start(tree->inode, needed);
++ struct buffer_head *bh;
++ int i;
++
++ if (IS_ERR(handle))
++ return PTR_ERR(handle);
++ if (from >= ex->ee_block && to == ex->ee_block + ex->ee_len - 1) {
++ /* tail removal */
++ unsigned long num, start;
++ num = ex->ee_block + ex->ee_len - from;
++ start = ex->ee_start + ex->ee_len - num;
++ ext_debug(tree, "free last %lu blocks starting %lu\n",
++ num, start);
++ for (i = 0; i < num; i++) {
++ bh = sb_find_get_block(tree->inode->i_sb, start + i);
++ ext3_forget(handle, 0, tree->inode, bh, start + i);
++ }
++ ext3_free_blocks(handle, tree->inode, start, num);
++ } else if (from == ex->ee_block && to <= ex->ee_block + ex->ee_len - 1) {
++ printk("strange request: removal %lu-%lu from %u:%u\n",
++ from, to, ex->ee_block, ex->ee_len);
++ } else {
++ printk("strange request: removal(2) %lu-%lu from %u:%u\n",
++ from, to, ex->ee_block, ex->ee_len);
++ }
++ ext3_journal_stop(handle);
++ return 0;
++}
++
++static int ext3_ext_find_goal(struct inode *inode,
++ struct ext3_ext_path *path, unsigned long block)
++{
++ struct ext3_inode_info *ei = EXT3_I(inode);
++ unsigned long bg_start;
++ unsigned long colour;
++ int depth;
++
++ if (path) {
++ struct ext3_extent *ex;
++ depth = path->p_depth;
++
++ /* try to predict block placement */
++ if ((ex = path[depth].p_ext))
++ return ex->ee_start + (block - ex->ee_block);
++
++ /* it looks index is empty
++ * try to find starting from index itself */
++ if (path[depth].p_bh)
++ return path[depth].p_bh->b_blocknr;
++ }
++
++ /* OK. use inode's group */
++ bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
++ le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
++ colour = (current->pid % 16) *
++ (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
++ return bg_start + colour + block;
++}
++
++static int ext3_new_block_cb(handle_t *handle, struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ struct ext3_extent *ex, int *err)
++{
++ struct inode *inode = tree->inode;
++ int newblock, goal;
++
++ EXT_ASSERT(path);
++ EXT_ASSERT(ex);
++ EXT_ASSERT(ex->ee_start);
++ EXT_ASSERT(ex->ee_len);
++
++ /* reuse block from the extent to order data/metadata */
++ newblock = ex->ee_start++;
++ ex->ee_len--;
++ if (ex->ee_len == 0) {
++ ex->ee_len = 1;
++ /* allocate new block for the extent */
++ goal = ext3_ext_find_goal(inode, path, ex->ee_block);
++ ex->ee_start = ext3_new_block(handle, inode, goal, err);
++ ex->ee_start_hi = 0;
++ if (ex->ee_start == 0) {
++ /* error occured: restore old extent */
++ ex->ee_start = newblock;
++ return 0;
++ }
++ }
++ return newblock;
++}
++
++static struct ext3_extents_helpers ext3_blockmap_helpers = {
++ .get_write_access = ext3_get_inode_write_access,
++ .mark_buffer_dirty = ext3_mark_buffer_dirty,
++ .mergable = ext3_ext_mergable,
++ .new_block = ext3_new_block_cb,
++ .remove_extent = ext3_remove_blocks,
++ .remove_extent_credits = ext3_remove_blocks_credits,
++};
++
++void ext3_init_tree_desc(struct ext3_extents_tree *tree,
++ struct inode *inode)
++{
++ tree->inode = inode;
++ tree->root = (void *) EXT3_I(inode)->i_data;
++ tree->buffer = (void *) inode;
++ tree->buffer_len = sizeof(EXT3_I(inode)->i_data);
++ tree->cex = (struct ext3_ext_cache *) &EXT3_I(inode)->i_cached_extent;
++ tree->ops = &ext3_blockmap_helpers;
++}
++
++int ext3_ext_get_block(handle_t *handle, struct inode *inode,
++ long iblock, struct buffer_head *bh_result,
++ int create, int extend_disksize)
++{
++ struct ext3_ext_path *path = NULL;
++ struct ext3_extent newex;
++ struct ext3_extent *ex;
++ int goal, newblock, err = 0, depth;
++ struct ext3_extents_tree tree;
++
++ clear_buffer_new(bh_result);
++ ext3_init_tree_desc(&tree, inode);
++ ext_debug(&tree, "block %d requested for inode %u\n",
++ (int) iblock, (unsigned) inode->i_ino);
++ down(&EXT3_I(inode)->truncate_sem);
++
++ /* check in cache */
++ if ((goal = ext3_ext_in_cache(&tree, iblock, &newex))) {
++ if (goal == EXT3_EXT_CACHE_GAP) {
++ if (!create) {
++ /* block isn't allocated yet and
++ * user don't want to allocate it */
++ goto out2;
++ }
++ /* we should allocate requested block */
++ } else if (goal == EXT3_EXT_CACHE_EXTENT) {
++ /* block is already allocated */
++ newblock = iblock - newex.ee_block + newex.ee_start;
++ goto out;
++ } else {
++ EXT_ASSERT(0);
++ }
++ }
++
++ /* find extent for this block */
++ path = ext3_ext_find_extent(&tree, iblock, NULL);
++ if (IS_ERR(path)) {
++ err = PTR_ERR(path);
++ path = NULL;
++ goto out2;
++ }
++
++ depth = EXT_DEPTH(&tree);
++
++ /*
++ * consistent leaf must not be empty
++ * this situations is possible, though, _during_ tree modification
++ * this is why assert can't be put in ext3_ext_find_extent()
++ */
++ EXT_ASSERT(path[depth].p_ext != NULL || depth == 0);
++
++ if ((ex = path[depth].p_ext)) {
++ /* if found exent covers block, simple return it */
++ if (iblock >= ex->ee_block && iblock < ex->ee_block + ex->ee_len) {
++ newblock = iblock - ex->ee_block + ex->ee_start;
++ ext_debug(&tree, "%d fit into %d:%d -> %d\n",
++ (int) iblock, ex->ee_block, ex->ee_len,
++ newblock);
++ ext3_ext_put_in_cache(&tree, ex->ee_block,
++ ex->ee_len, ex->ee_start,
++ EXT3_EXT_CACHE_EXTENT);
++ goto out;
++ }
++ }
++
++ /*
++ * requested block isn't allocated yet
++ * we couldn't try to create block if create flag is zero
++ */
++ if (!create) {
++ /* put just found gap into cache to speedup subsequest reqs */
++ ext3_ext_put_gap_in_cache(&tree, path, iblock);
++ goto out2;
++ }
++
++ /* allocate new block */
++ goal = ext3_ext_find_goal(inode, path, iblock);
++ newblock = ext3_new_block(handle, inode, goal, &err);
++ if (!newblock)
++ goto out2;
++ ext_debug(&tree, "allocate new block: goal %d, found %d\n",
++ goal, newblock);
++
++ /* try to insert new extent into found leaf and return */
++ newex.ee_block = iblock;
++ newex.ee_start = newblock;
++ newex.ee_start_hi = 0;
++ newex.ee_len = 1;
++ err = ext3_ext_insert_extent(handle, &tree, path, &newex);
++ if (err)
++ goto out2;
++
++ if (extend_disksize && inode->i_size > EXT3_I(inode)->i_disksize)
++ EXT3_I(inode)->i_disksize = inode->i_size;
++
++ /* previous routine could use block we allocated */
++ newblock = newex.ee_start;
++ set_buffer_new(bh_result);
++
++ ext3_ext_put_in_cache(&tree, newex.ee_block, newex.ee_len,
++ newex.ee_start, EXT3_EXT_CACHE_EXTENT);
++out:
++ ext3_ext_show_leaf(&tree, path);
++ map_bh(bh_result, inode->i_sb, newblock);
++out2:
++ if (path) {
++ ext3_ext_drop_refs(path);
++ kfree(path);
++ }
++ up(&EXT3_I(inode)->truncate_sem);
++
++ return err;
++}
++
++void ext3_ext_truncate(struct inode * inode, struct page *page)
++{
++ struct address_space *mapping = inode->i_mapping;
++ struct super_block *sb = inode->i_sb;
++ struct ext3_extents_tree tree;
++ unsigned long last_block;
++ handle_t *handle;
++ int err = 0;
++
++ ext3_init_tree_desc(&tree, inode);
++
++ /*
++ * probably first extent we're gonna free will be last in block
++ */
++ err = ext3_writepage_trans_blocks(inode) + 3;
++ handle = ext3_journal_start(inode, err);
++ if (IS_ERR(handle)) {
++ if (page) {
++ clear_highpage(page);
++ flush_dcache_page(page);
++ unlock_page(page);
++ page_cache_release(page);
++ }
++ return;
++ }
++
++ if (page)
++ ext3_block_truncate_page(handle, page, mapping, inode->i_size);
++
++ down(&EXT3_I(inode)->truncate_sem);
++ ext3_ext_invalidate_cache(&tree);
++
++ /*
++ * TODO: optimization is possible here
++ * probably we need not scaning at all,
++ * because page truncation is enough
++ */
++ if (ext3_orphan_add(handle, inode))
++ goto out_stop;
++
++ /* we have to know where to truncate from in crash case */
++ EXT3_I(inode)->i_disksize = inode->i_size;
++ ext3_mark_inode_dirty(handle, inode);
++
++ last_block = (inode->i_size + sb->s_blocksize - 1) >>
++ EXT3_BLOCK_SIZE_BITS(sb);
++ err = ext3_ext_remove_space(&tree, last_block, EXT_MAX_BLOCK);
++
++ /* In a multi-transaction truncate, we only make the final
++ * transaction synchronous */
++ if (IS_SYNC(inode))
++ handle->h_sync = 1;
++
++out_stop:
++ /*
++ * If this was a simple ftruncate(), and the file will remain alive
++ * then we need to clear up the orphan record which we created above.
++ * However, if this was a real unlink then we were called by
++ * ext3_delete_inode(), and we allow that function to clean up the
++ * orphan info for us.
++ */
++ if (inode->i_nlink)
++ ext3_orphan_del(handle, inode);
++
++ up(&EXT3_I(inode)->truncate_sem);
++ ext3_journal_stop(handle);
++}
++
++/*
++ * this routine calculate max number of blocks we could modify
++ * in order to allocate new block for an inode
++ */
++int ext3_ext_writepage_trans_blocks(struct inode *inode, int num)
++{
++ struct ext3_extents_tree tree;
++ int needed;
++
++ ext3_init_tree_desc(&tree, inode);
++
++ needed = ext3_ext_calc_credits_for_insert(&tree, NULL);
++
++ /* caller want to allocate num blocks */
++ needed *= num;
++
++#ifdef CONFIG_QUOTA
++ /*
++ * FIXME: real calculation should be here
++ * it depends on blockmap format of qouta file
++ */
++ needed += 2 * EXT3_SINGLEDATA_TRANS_BLOCKS;
++#endif
++
++ return needed;
++}
++
++void ext3_extents_initialize_blockmap(handle_t *handle, struct inode *inode)
++{
++ struct ext3_extents_tree tree;
++
++ ext3_init_tree_desc(&tree, inode);
++ ext3_extent_tree_init(handle, &tree);
++}
++
++int ext3_ext_calc_blockmap_metadata(struct inode *inode, int blocks)
++{
++ struct ext3_extents_tree tree;
++
++ ext3_init_tree_desc(&tree, inode);
++ return ext3_ext_calc_metadata_amount(&tree, blocks);
++}
++
++static int
++ext3_ext_store_extent_cb(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ struct ext3_ext_cache *newex)
++{
++ struct ext3_extent_buf *buf = (struct ext3_extent_buf *) tree->private;
++
++ if (newex->ec_type != EXT3_EXT_CACHE_EXTENT)
++ return EXT_CONTINUE;
++
++ if (buf->err < 0)
++ return EXT_BREAK;
++ if (buf->cur - buf->buffer + sizeof(*newex) > buf->buflen)
++ return EXT_BREAK;
++
++ if (!copy_to_user(buf->cur, newex, sizeof(*newex))) {
++ buf->err++;
++ buf->cur += sizeof(*newex);
++ } else {
++ buf->err = -EFAULT;
++ return EXT_BREAK;
++ }
++ return EXT_CONTINUE;
++}
++
++static int
++ext3_ext_collect_stats_cb(struct ext3_extents_tree *tree,
++ struct ext3_ext_path *path,
++ struct ext3_ext_cache *ex)
++{
++ struct ext3_extent_tree_stats *buf =
++ (struct ext3_extent_tree_stats *) tree->private;
++ int depth;
++
++ if (ex->ec_type != EXT3_EXT_CACHE_EXTENT)
++ return EXT_CONTINUE;
++
++ depth = EXT_DEPTH(tree);
++ buf->extents_num++;
++ if (path[depth].p_ext == EXT_FIRST_EXTENT(path[depth].p_hdr))
++ buf->leaf_num++;
++ return EXT_CONTINUE;
++}
++
++int ext3_ext_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
++ unsigned long arg)
++{
++ int err = 0;
++
++ if (!(EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL))
++ return -EINVAL;
++
++ if (cmd == EXT3_IOC_GET_EXTENTS) {
++ struct ext3_extent_buf buf;
++ struct ext3_extents_tree tree;
++
++ if (copy_from_user(&buf, (void *) arg, sizeof(buf)))
++ return -EFAULT;
++
++ ext3_init_tree_desc(&tree, inode);
++ buf.cur = buf.buffer;
++ buf.err = 0;
++ tree.private = &buf;
++ down(&EXT3_I(inode)->truncate_sem);
++ err = ext3_ext_walk_space(&tree, buf.start, EXT_MAX_BLOCK,
++ ext3_ext_store_extent_cb);
++ up(&EXT3_I(inode)->truncate_sem);
++ if (err == 0)
++ err = buf.err;
++ } else if (cmd == EXT3_IOC_GET_TREE_STATS) {
++ struct ext3_extent_tree_stats buf;
++ struct ext3_extents_tree tree;
++
++ ext3_init_tree_desc(&tree, inode);
++ down(&EXT3_I(inode)->truncate_sem);
++ buf.depth = EXT_DEPTH(&tree);
++ buf.extents_num = 0;
++ buf.leaf_num = 0;
++ tree.private = &buf;
++ err = ext3_ext_walk_space(&tree, 0, EXT_MAX_BLOCK,
++ ext3_ext_collect_stats_cb);
++ up(&EXT3_I(inode)->truncate_sem);
++ if (!err)
++ err = copy_to_user((void *) arg, &buf, sizeof(buf));
++ } else if (cmd == EXT3_IOC_GET_TREE_DEPTH) {
++ struct ext3_extents_tree tree;
++ ext3_init_tree_desc(&tree, inode);
++ down(&EXT3_I(inode)->truncate_sem);
++ err = EXT_DEPTH(&tree);
++ up(&EXT3_I(inode)->truncate_sem);
++ }
++
++ return err;
++}
++
++EXPORT_SYMBOL(ext3_init_tree_desc);
++EXPORT_SYMBOL(ext3_mark_inode_dirty);
++EXPORT_SYMBOL(ext3_ext_invalidate_cache);
++EXPORT_SYMBOL(ext3_ext_insert_extent);
++EXPORT_SYMBOL(ext3_ext_walk_space);
++EXPORT_SYMBOL(ext3_ext_find_goal);
++EXPORT_SYMBOL(ext3_ext_calc_credits_for_insert);
+Index: linux-2.6.16.21-0.8/fs/ext3/ialloc.c
+===================================================================
+--- linux-2.6.16.21-0.8.orig/fs/ext3/ialloc.c
++++ linux-2.6.16.21-0.8/fs/ext3/ialloc.c
+@@ -598,7 +598,7 @@ got:
+ ei->i_dir_start_lookup = 0;
+ ei->i_disksize = 0;
+
+- ei->i_flags = EXT3_I(dir)->i_flags & ~EXT3_INDEX_FL;
++ ei->i_flags = EXT3_I(dir)->i_flags & ~(EXT3_INDEX_FL|EXT3_EXTENTS_FL);
+ if (S_ISLNK(mode))
+ ei->i_flags &= ~(EXT3_IMMUTABLE_FL|EXT3_APPEND_FL);
+ /* dirsync only applies to directories */
+@@ -642,6 +642,18 @@ got:
+ if (err)
+ goto fail_free_drop;
+
++ if (test_opt(sb, EXTENTS) && S_ISREG(inode->i_mode)) {
++ EXT3_I(inode)->i_flags |= EXT3_EXTENTS_FL;
++ ext3_extents_initialize_blockmap(handle, inode);
++ if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_EXTENTS)) {
++ err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh);
++ if (err) goto fail;
++ EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_EXTENTS);
++ BUFFER_TRACE(EXT3_SB(sb)->s_sbh, "call ext3_journal_dirty_metadata");
++ err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
++ }
++ }
++
+ err = ext3_mark_inode_dirty(handle, inode);
+ if (err) {
+ ext3_std_error(sb, err);
+Index: linux-2.6.16.21-0.8/fs/ext3/inode.c
+===================================================================
+--- linux-2.6.16.21-0.8.orig/fs/ext3/inode.c
++++ linux-2.6.16.21-0.8/fs/ext3/inode.c
+@@ -40,7 +40,7 @@
+ #include "iopen.h"
+ #include "acl.h"
+
+-static int ext3_writepage_trans_blocks(struct inode *inode);
++int ext3_writepage_trans_blocks(struct inode *inode);
+
+ /*
+ * Test whether an inode is a fast symlink.
+@@ -788,6 +788,17 @@ out:
+ return err;
+ }
+
++static inline int
++ext3_get_block_wrap(handle_t *handle, struct inode *inode, long block,
++ struct buffer_head *bh, int create, int extend_disksize)
++{
++ if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
++ return ext3_ext_get_block(handle, inode, block, bh, create,
++ extend_disksize);
++ return ext3_get_block_handle(handle, inode, block, bh, create,
++ extend_disksize);
++}
++
+ static int ext3_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+ {
+@@ -798,8 +809,8 @@ static int ext3_get_block(struct inode *
+ handle = ext3_journal_current_handle();
+ J_ASSERT(handle != 0);
+ }
+- ret = ext3_get_block_handle(handle, inode, iblock,
+- bh_result, create, 1);
++ ret = ext3_get_block_wrap(handle, inode, iblock,
++ bh_result, create, 1);
+ return ret;
+ }
+
+@@ -843,7 +854,7 @@ ext3_direct_io_get_blocks(struct inode *
+
+ get_block:
+ if (ret == 0)
+- ret = ext3_get_block_handle(handle, inode, iblock,
++ ret = ext3_get_block_wrap(handle, inode, iblock,
+ bh_result, create, 0);
+ bh_result->b_size = (1 << inode->i_blkbits);
+ return ret;
+@@ -863,7 +874,7 @@ struct buffer_head *ext3_getblk(handle_t
+ dummy.b_state = 0;
+ dummy.b_blocknr = -1000;
+ buffer_trace_init(&dummy.b_history);
+- *errp = ext3_get_block_handle(handle, inode, block, &dummy, create, 1);
++ *errp = ext3_get_block_wrap(handle, inode, block, &dummy, create, 1);
+ if (!*errp && buffer_mapped(&dummy)) {
+ struct buffer_head *bh;
+ bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
+@@ -1606,7 +1617,7 @@ void ext3_set_aops(struct inode *inode)
+ * This required during truncate. We need to physically zero the tail end
+ * of that block so it doesn't yield old data if the file is later grown.
+ */
+-static int ext3_block_truncate_page(handle_t *handle, struct page *page,
++int ext3_block_truncate_page(handle_t *handle, struct page *page,
+ struct address_space *mapping, loff_t from)
+ {
+ unsigned long index = from >> PAGE_CACHE_SHIFT;
+@@ -2116,6 +2127,9 @@ void ext3_truncate(struct inode * inode)
+ return;
+ }
+
++ if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
++ return ext3_ext_truncate(inode, page);
++
+ handle = start_transaction(inode);
+ if (IS_ERR(handle)) {
+ if (page) {
+@@ -2863,12 +2877,15 @@ err_out:
+ * block and work out the exact number of indirects which are touched. Pah.
+ */
+
+-static int ext3_writepage_trans_blocks(struct inode *inode)
++int ext3_writepage_trans_blocks(struct inode *inode)
+ {
+ int bpp = ext3_journal_blocks_per_page(inode);
+ int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
+ int ret;
+
++ if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
++ return ext3_ext_writepage_trans_blocks(inode, bpp);
++
+ if (ext3_should_journal_data(inode))
+ ret = 3 * (bpp + indirects) + 2;
+ else
+Index: linux-2.6.16.21-0.8/fs/ext3/Makefile
+===================================================================
+--- linux-2.6.16.21-0.8.orig/fs/ext3/Makefile
++++ linux-2.6.16.21-0.8/fs/ext3/Makefile
+@@ -5,7 +5,8 @@
+ obj-$(CONFIG_EXT3_FS) += ext3.o
+
+ ext3-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o iopen.o \
+- ioctl.o namei.o super.o symlink.o hash.o resize.o
++ ioctl.o namei.o super.o symlink.o hash.o resize.o \
++ extents.o
+
+ ext3-$(CONFIG_EXT3_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o
+ ext3-$(CONFIG_EXT3_FS_POSIX_ACL) += acl.o
+Index: linux-2.6.16.21-0.8/fs/ext3/super.c
+===================================================================
+--- linux-2.6.16.21-0.8.orig/fs/ext3/super.c
++++ linux-2.6.16.21-0.8/fs/ext3/super.c
+@@ -392,6 +392,7 @@ static void ext3_put_super (struct super
+ struct ext3_super_block *es = sbi->s_es;
+ int i;
+
++ ext3_ext_release(sb);
+ ext3_xattr_put_super(sb);
+ journal_destroy(sbi->s_journal);
+ if (!(sb->s_flags & MS_RDONLY)) {
+@@ -456,6 +457,8 @@ static struct inode *ext3_alloc_inode(st
+ #endif
+ ei->i_block_alloc_info = NULL;
+ ei->vfs_inode.i_version = 1;
++
++ memset(&ei->i_cached_extent, 0, sizeof(ei->i_cached_extent));
+ return &ei->vfs_inode;
+ }
+
+@@ -638,6 +641,7 @@ enum {
+ Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
+ Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
+ Opt_iopen, Opt_noiopen, Opt_iopen_nopriv,
++ Opt_extents, Opt_noextents, Opt_extdebug,
+ Opt_grpquota
+ };
+
+@@ -689,6 +693,9 @@ static match_table_t tokens = {
+ {Opt_iopen, "iopen"},
+ {Opt_noiopen, "noiopen"},
+ {Opt_iopen_nopriv, "iopen_nopriv"},
++ {Opt_extents, "extents"},
++ {Opt_noextents, "noextents"},
++ {Opt_extdebug, "extdebug"},
+ {Opt_barrier, "barrier=%u"},
+ {Opt_err, NULL},
+ {Opt_resize, "resize"},
+@@ -1030,6 +1036,15 @@ clear_qf_name:
+ case Opt_nobh:
+ set_opt(sbi->s_mount_opt, NOBH);
+ break;
++ case Opt_extents:
++ set_opt (sbi->s_mount_opt, EXTENTS);
++ break;
++ case Opt_noextents:
++ clear_opt (sbi->s_mount_opt, EXTENTS);
++ break;
++ case Opt_extdebug:
++ set_opt (sbi->s_mount_opt, EXTDEBUG);
++ break;
+ default:
+ printk (KERN_ERR
+ "EXT3-fs: Unrecognized mount option \"%s\" "
+@@ -1756,6 +1768,7 @@ static int ext3_fill_super (struct super
+ percpu_counter_mod(&sbi->s_dirs_counter,
+ ext3_count_dirs(sb));
+
++ ext3_ext_init(sb);
+ lock_kernel();
+ return 0;
+
+Index: linux-2.6.16.21-0.8/fs/ext3/ioctl.c
+===================================================================
+--- linux-2.6.16.21-0.8.orig/fs/ext3/ioctl.c
++++ linux-2.6.16.21-0.8/fs/ext3/ioctl.c
+@@ -125,6 +125,10 @@ flags_err:
+ err = ext3_change_inode_journal_flag(inode, jflag);
+ return err;
+ }
++ case EXT3_IOC_GET_EXTENTS:
++ case EXT3_IOC_GET_TREE_STATS:
++ case EXT3_IOC_GET_TREE_DEPTH:
++ return ext3_ext_ioctl(inode, filp, cmd, arg);
+ case EXT3_IOC_GETVERSION:
+ case EXT3_IOC_GETVERSION_OLD:
+ return put_user(inode->i_generation, (int __user *) arg);
+Index: linux-2.6.16.21-0.8/include/linux/ext3_fs.h
+===================================================================
+--- linux-2.6.16.21-0.8.orig/include/linux/ext3_fs.h
++++ linux-2.6.16.21-0.8/include/linux/ext3_fs.h
+@@ -185,9 +185,10 @@ struct ext3_group_desc
+ #define EXT3_NOTAIL_FL 0x00008000 /* file tail should not be merged */
+ #define EXT3_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */
+ #define EXT3_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
++#define EXT3_EXTENTS_FL 0x00080000 /* Inode uses extents */
+ #define EXT3_RESERVED_FL 0x80000000 /* reserved for ext3 lib */
+
+-#define EXT3_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */
++#define EXT3_FL_USER_VISIBLE 0x000BDFFF /* User visible flags */
+ #define EXT3_FL_USER_MODIFIABLE 0x000380FF /* User modifiable flags */
+
+ /*
+@@ -237,6 +238,9 @@ struct ext3_new_group_data {
+ #endif
+ #define EXT3_IOC_GETRSVSZ _IOR('f', 5, long)
+ #define EXT3_IOC_SETRSVSZ _IOW('f', 6, long)
++#define EXT3_IOC_GET_EXTENTS _IOR('f', 7, long)
++#define EXT3_IOC_GET_TREE_DEPTH _IOR('f', 8, long)
++#define EXT3_IOC_GET_TREE_STATS _IOR('f', 9, long)
+
+ /*
+ * Mount options
+@@ -377,6 +381,8 @@ struct ext3_inode {
+ #define EXT3_MOUNT_GRPQUOTA 0x200000 /* "old" group quota */
+ #define EXT3_MOUNT_IOPEN 0x400000 /* Allow access via iopen */
+ #define EXT3_MOUNT_IOPEN_NOPRIV 0x800000/* Make iopen world-readable */
++#define EXT3_MOUNT_EXTENTS 0x1000000/* Extents support */
++#define EXT3_MOUNT_EXTDEBUG 0x2000000/* Extents debug */
+
+ /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
+ #ifndef clear_opt
+@@ -565,11 +571,13 @@ static inline struct ext3_inode_info *EX
+ #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */
+ #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
+ #define EXT3_FEATURE_INCOMPAT_META_BG 0x0010
++#define EXT3_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
+
+ #define EXT3_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
+ #define EXT3_FEATURE_INCOMPAT_SUPP (EXT3_FEATURE_INCOMPAT_FILETYPE| \
+ EXT3_FEATURE_INCOMPAT_RECOVER| \
+- EXT3_FEATURE_INCOMPAT_META_BG)
++ EXT3_FEATURE_INCOMPAT_META_BG| \
++ EXT3_FEATURE_INCOMPAT_EXTENTS)
+ #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT3_FEATURE_RO_COMPAT_BTREE_DIR)
+@@ -776,6 +784,7 @@ extern unsigned long ext3_count_free (st
+
+
+ /* inode.c */
++extern int ext3_block_truncate_page(handle_t *, struct page *, struct address_space *, loff_t);
+ extern int ext3_forget(handle_t *, int, struct inode *, struct buffer_head *, int);
+ extern struct buffer_head * ext3_getblk (handle_t *, struct inode *, long, int, int *);
+ extern struct buffer_head * ext3_bread (handle_t *, struct inode *, int, int, int *);
+@@ -792,6 +801,7 @@ extern int ext3_get_inode_loc(struct ino
+ extern void ext3_truncate (struct inode *);
+ extern void ext3_set_inode_flags(struct inode *);
+ extern void ext3_set_aops(struct inode *inode);
++extern int ext3_writepage_trans_blocks(struct inode *inode);
+
+ /* ioctl.c */
+ extern int ext3_ioctl (struct inode *, struct file *, unsigned int,
+@@ -845,6 +855,16 @@ extern struct inode_operations ext3_spec
+ extern struct inode_operations ext3_symlink_inode_operations;
+ extern struct inode_operations ext3_fast_symlink_inode_operations;
+
++/* extents.c */
++extern int ext3_ext_writepage_trans_blocks(struct inode *, int);
++extern int ext3_ext_get_block(handle_t *, struct inode *, long,
++ struct buffer_head *, int, int);
++extern void ext3_ext_truncate(struct inode *, struct page *);
++extern void ext3_ext_init(struct super_block *);
++extern void ext3_ext_release(struct super_block *);
++extern void ext3_extents_initialize_blockmap(handle_t *, struct inode *);
++extern int ext3_ext_ioctl(struct inode *inode, struct file *filp,
++ unsigned int cmd, unsigned long arg);
+
+ #endif /* __KERNEL__ */
+
+Index: linux-2.6.16.21-0.8/include/linux/ext3_extents.h
+===================================================================
+--- /dev/null
++++ linux-2.6.16.21-0.8/include/linux/ext3_extents.h
+@@ -0,0 +1,262 @@
++/*
++ * Copyright (c) 2003, Cluster File Systems, Inc, info@clusterfs.com
++ * Written by Alex Tomas <alex@clusterfs.com>
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public Licens
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
++ */
++
++#ifndef _LINUX_EXT3_EXTENTS
++#define _LINUX_EXT3_EXTENTS
++
++/*
++ * with AGRESSIVE_TEST defined capacity of index/leaf blocks
++ * become very little, so index split, in-depth growing and
++ * other hard changes happens much more often
++ * this is for debug purposes only
++ */
++#define AGRESSIVE_TEST_
++
++/*
++ * if CHECK_BINSEARCH defined, then results of binary search
++ * will be checked by linear search
++ */
++#define CHECK_BINSEARCH_
++
++/*
++ * if EXT_DEBUG is defined you can use 'extdebug' mount option
++ * to get lots of info what's going on
++ */
++#define EXT_DEBUG_
++#ifdef EXT_DEBUG
++#define ext_debug(tree,fmt,a...) \
++do { \
++ if (test_opt((tree)->inode->i_sb, EXTDEBUG)) \
++ printk(fmt, ##a); \
++} while (0);
++#else
++#define ext_debug(tree,fmt,a...)
++#endif
++
++/*
++ * if EXT_STATS is defined then stats numbers are collected
++ * these number will be displayed at umount time
++ */
++#define EXT_STATS_
++
++
++#define EXT3_ALLOC_NEEDED 3 /* block bitmap + group desc. + sb */
++
++/*
++ * ext3_inode has i_block array (total 60 bytes)
++ * first 4 bytes are used to store:
++ * - tree depth (0 mean there is no tree yet. all extents in the inode)
++ * - number of alive extents in the inode
++ */
++
++/*
++ * this is extent on-disk structure
++ * it's used at the bottom of the tree
++ */
++struct ext3_extent {
++ __u32 ee_block; /* first logical block extent covers */
++ __u16 ee_len; /* number of blocks covered by extent */
++ __u16 ee_start_hi; /* high 16 bits of physical block */
++ __u32 ee_start; /* low 32 bigs of physical block */
++};
++
++/*
++ * this is index on-disk structure
++ * it's used at all the levels, but the bottom
++ */
++struct ext3_extent_idx {
++ __u32 ei_block; /* index covers logical blocks from 'block' */
++ __u32 ei_leaf; /* pointer to the physical block of the next *
++ * level. leaf or next index could bet here */
++ __u16 ei_leaf_hi; /* high 16 bits of physical block */
++ __u16 ei_unused;
++};
++
++/*
++ * each block (leaves and indexes), even inode-stored has header
++ */
++struct ext3_extent_header {
++ __u16 eh_magic; /* probably will support different formats */
++ __u16 eh_entries; /* number of valid entries */
++ __u16 eh_max; /* capacity of store in entries */
++ __u16 eh_depth; /* has tree real underlaying blocks? */
++ __u32 eh_generation; /* flags(8 bits) | generation of the tree */
++};
++
++#define EXT3_EXT_MAGIC 0xf30a
++
++/*
++ * array of ext3_ext_path contains path to some extent
++ * creation/lookup routines use it for traversal/splitting/etc
++ * truncate uses it to simulate recursive walking
++ */
++struct ext3_ext_path {
++ __u32 p_block;
++ __u16 p_depth;
++ struct ext3_extent *p_ext;
++ struct ext3_extent_idx *p_idx;
++ struct ext3_extent_header *p_hdr;
++ struct buffer_head *p_bh;
++};
++
++/*
++ * structure for external API
++ */
++
++/*
++ * storage for cached extent
++ */
++struct ext3_ext_cache {
++ __u32 ec_start;
++ __u32 ec_block;
++ __u32 ec_len;
++ __u32 ec_type;
++};
++
++#define EXT3_EXT_CACHE_NO 0
++#define EXT3_EXT_CACHE_GAP 1
++#define EXT3_EXT_CACHE_EXTENT 2
++
++/*
++ * ext3_extents_tree is used to pass initial information
++ * to top-level extents API
++ */
++struct ext3_extents_helpers;
++struct ext3_extents_tree {
++ struct inode *inode; /* inode which tree belongs to */
++ void *root; /* ptr to data top of tree resides at */
++ void *buffer; /* will be passed as arg to ^^ routines */
++ int buffer_len;
++ void *private;
++ struct ext3_ext_cache *cex;/* last found extent */
++ struct ext3_extents_helpers *ops;
++};
++
++struct ext3_extents_helpers {
++ int (*get_write_access)(handle_t *h, void *buffer);
++ int (*mark_buffer_dirty)(handle_t *h, void *buffer);
++ int (*mergable)(struct ext3_extent *ex1, struct ext3_extent *ex2);
++ int (*remove_extent_credits)(struct ext3_extents_tree *,
++ struct ext3_extent *, unsigned long,
++ unsigned long);
++ int (*remove_extent)(struct ext3_extents_tree *,
++ struct ext3_extent *, unsigned long,
++ unsigned long);
++ int (*new_block)(handle_t *, struct ext3_extents_tree *,
++ struct ext3_ext_path *, struct ext3_extent *,
++ int *);
++};
++
++/*
++ * to be called by ext3_ext_walk_space()
++ * negative retcode - error
++ * positive retcode - signal for ext3_ext_walk_space(), see below
++ * callback must return valid extent (passed or newly created)
++ */
++typedef int (*ext_prepare_callback)(struct ext3_extents_tree *,
++ struct ext3_ext_path *,
++ struct ext3_ext_cache *);
++
++#define EXT_CONTINUE 0
++#define EXT_BREAK 1
++#define EXT_REPEAT 2
++
++
++#define EXT_MAX_BLOCK 0xffffffff
++
++
++#define EXT_FIRST_EXTENT(__hdr__) \
++ ((struct ext3_extent *) (((char *) (__hdr__)) + \
++ sizeof(struct ext3_extent_header)))
++#define EXT_FIRST_INDEX(__hdr__) \
++ ((struct ext3_extent_idx *) (((char *) (__hdr__)) + \
++ sizeof(struct ext3_extent_header)))
++#define EXT_HAS_FREE_INDEX(__path__) \
++ ((__path__)->p_hdr->eh_entries < (__path__)->p_hdr->eh_max)
++#define EXT_LAST_EXTENT(__hdr__) \
++ (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_entries - 1)
++#define EXT_LAST_INDEX(__hdr__) \
++ (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_entries - 1)
++#define EXT_MAX_EXTENT(__hdr__) \
++ (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_max - 1)
++#define EXT_MAX_INDEX(__hdr__) \
++ (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_max - 1)
++#define EXT_HDR_GEN(__hdr__) ((__hdr__)->eh_generation & 0x00ffffff)
++#define EXT_FLAGS(__hdr__) ((__hdr__)->eh_generation >> 24)
++#define EXT_FLAGS_CLR_UNKNOWN 0x7 /* Flags cleared on modification */
++
++#define EXT_BLOCK_HDR(__bh__) ((struct ext3_extent_header *)(__bh__)->b_data)
++#define EXT_ROOT_HDR(__tree__) ((struct ext3_extent_header *)(__tree__)->root)
++#define EXT_DEPTH(__tree__) (EXT_ROOT_HDR(__tree__)->eh_depth)
++#define EXT_GENERATION(__tree__) EXT_HDR_GEN(EXT_ROOT_HDR(__tree__))
++
++#define EXT_ASSERT(__x__) if (!(__x__)) BUG();
++
++#define EXT_CHECK_PATH(tree,path) \
++{ \
++ int depth = EXT_DEPTH(tree); \
++ BUG_ON((unsigned long) (path) < __PAGE_OFFSET); \
++ BUG_ON((unsigned long) (path)[depth].p_idx < \
++ __PAGE_OFFSET && (path)[depth].p_idx != NULL); \
++ BUG_ON((unsigned long) (path)[depth].p_ext < \
++ __PAGE_OFFSET && (path)[depth].p_ext != NULL); \
++ BUG_ON((unsigned long) (path)[depth].p_hdr < __PAGE_OFFSET); \
++ BUG_ON((unsigned long) (path)[depth].p_bh < __PAGE_OFFSET \
++ && depth != 0); \
++ BUG_ON((path)[0].p_depth != depth); \
++}
++
++
++/*
++ * this structure is used to gather extents from the tree via ioctl
++ */
++struct ext3_extent_buf {
++ unsigned long start;
++ int buflen;
++ void *buffer;
++ void *cur;
++ int err;
++};
++
++/*
++ * this structure is used to collect stats info about the tree
++ */
++struct ext3_extent_tree_stats {
++ int depth;
++ int extents_num;
++ int leaf_num;
++};
++
++extern void ext3_init_tree_desc(struct ext3_extents_tree *, struct inode *);
++extern int ext3_extent_tree_init(handle_t *, struct ext3_extents_tree *);
++extern int ext3_ext_calc_credits_for_insert(struct ext3_extents_tree *, struct ext3_ext_path *);
++extern int ext3_ext_insert_extent(handle_t *, struct ext3_extents_tree *, struct ext3_ext_path *, struct ext3_extent *);
++extern int ext3_ext_walk_space(struct ext3_extents_tree *, unsigned long, unsigned long, ext_prepare_callback);
++extern int ext3_ext_remove_space(struct ext3_extents_tree *, unsigned long, unsigned long);
++extern struct ext3_ext_path * ext3_ext_find_extent(struct ext3_extents_tree *, int, struct ext3_ext_path *);
++extern int ext3_ext_calc_blockmap_metadata(struct inode *, int);
++
++static inline void
++ext3_ext_invalidate_cache(struct ext3_extents_tree *tree)
++{
++ if (tree->cex)
++ tree->cex->ec_type = EXT3_EXT_CACHE_NO;
++}
++
++
++#endif /* _LINUX_EXT3_EXTENTS */
+Index: linux-2.6.16.21-0.8/include/linux/ext3_fs_i.h
+===================================================================
+--- linux-2.6.16.21-0.8.orig/include/linux/ext3_fs_i.h
++++ linux-2.6.16.21-0.8/include/linux/ext3_fs_i.h
+@@ -133,6 +133,8 @@ struct ext3_inode_info {
+ */
+ struct semaphore truncate_sem;
+ struct inode vfs_inode;
++
++ __u32 i_cached_extent[4];
+ };
+
+ #endif /* _LINUX_EXT3_FS_I */
git://git.whamcloud.com / fs / lustre-release.git / blobdiff