ext3-extents-2.4.20.patch 72.18 KiB
Index: linux-2.4.24/fs/ext3/extents.c
===================================================================
--- linux-2.4.24.orig/fs/ext3/extents.c 2003-01-30 13:24:37.000000000 +0300
+++ linux-2.4.24/fs/ext3/extents.c 2004-01-28 20:01:16.000000000 +0300
@@ -0,0 +1,2254 @@
+/*
+ * Copyright (C) 2003 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/locks.h>
+#include <linux/ext3_extents.h>
+#include <asm/uaccess.h>
+
+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->get_write_access)
+ return tree->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->mark_buffer_dirty)
+ return tree->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)
+{
+ if (path->p_bh) {
+ /* path points to block */
+ return ext3_journal_get_write_access(handle, path->p_bh);
+ }
+
+ /* path points to leaf/index in inode body */
+ return ext3_ext_get_access_for_root(handle, tree);
+}
+
+/*
+ * could return:
+ * - EROFS
+ * - ENOMEM
+ * - EIO
+ */
+static int ext3_ext_dirty(handle_t *handle, struct ext3_extents_tree *tree,
+ struct ext3_ext_path *path)
+{
+ if (path->p_bh) {
+ /* path points to block */
+ return ext3_journal_dirty_metadata(handle, path->p_bh);
+ }
+
+ /* path points to leaf/index in inode body */
+ return ext3_ext_mark_root_dirty(handle, tree);
+}
+
+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->new_block)
+ return tree->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, 0, 0, err);
+ return newblock;
+}
+
+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->e_block,
+ path->p_idx->e_leaf);
+ } else if (path->p_ext) {
+ ext_debug(tree, " %d:%d:%d",
+ path->p_ext->e_block,
+ path->p_ext->e_num,
+ path->p_ext->e_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->e_num; i++, ex++) {
+ ext_debug(tree, "%d:%d:%d ",
+ ex->e_block, ex->e_num, ex->e_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->e_magic == EXT3_EXT_MAGIC);
+ EXT_ASSERT(eh->e_num <= eh->e_max);
+ EXT_ASSERT(eh->e_num > 0);
+
+ ext_debug(tree, "binsearch for %d(idx): ", block);
+
+ path->p_idx = ix = EXT_FIRST_INDEX(eh);
+
+ r = k = eh->e_num;
+ while (k > 1) {+ k = (r - l) / 2;
+ if (block < ix[l + k].e_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->e_block, path->p_idx->e_leaf);
+
+ while (l++ < r) {
+ if (block < ix->e_block)
+ break;
+ path->p_idx = ix++;
+ }
+ ext_debug(tree, " -> %d->%d\n", path->p_idx->e_block,
+ path->p_idx->e_leaf);
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext3_extent_idx *chix;
+
+ chix = ix = EXT_FIRST_INDEX(eh);
+ for (k = 0; k < eh->e_num; k++, ix++) {
+ if (k != 0 && ix->e_block <= ix[-1].e_block) {
+ printk("k=%d, ix=0x%p, first=0x%p\n", k,
+ ix, EXT_FIRST_INDEX(eh));
+ printk("%u <= %u\n",
+ ix->e_block,ix[-1].e_block);
+ }
+ EXT_ASSERT(k == 0 || ix->e_block > ix[-1].e_block);
+ if (block < ix->e_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->e_magic == EXT3_EXT_MAGIC);
+ EXT_ASSERT(eh->e_num <= eh->e_max);
+
+ if (eh->e_num == 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->e_num;+ while (k > 1) {
+ k = (r - l) / 2;
+ if (block < ex[l + k].e_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->e_block,
+ path->p_ext->e_start, path->p_ext->e_num);
+
+ while (l++ < r) {
+ if (block < ex->e_block)
+ break;
+ path->p_ext = ex++;
+ }
+ ext_debug(tree, " -> %d:%d:%d\n", path->p_ext->e_block,
+ path->p_ext->e_start, path->p_ext->e_num);
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext3_extent *chex;
+
+ chex = ex = EXT_FIRST_EXTENT(eh);
+ for (k = 0; k < eh->e_num; k++, ex++) {
+ EXT_ASSERT(k == 0 || ex->e_block > ex[-1].e_block);
+ if (block < ex->e_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->e_depth = 0;
+ eh->e_num = 0;
+ eh->e_magic = EXT3_EXT_MAGIC;
+ eh->e_max = ext3_ext_space_root(tree);
+ ext3_ext_mark_root_dirty(handle, 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);
+ i = depth = EXT_DEPTH(tree);
+ EXT_ASSERT(eh->e_max);
+ EXT_ASSERT(eh->e_magic == EXT3_EXT_MAGIC);+ EXT_ASSERT(i == 0 || eh->e_num > 0);
+
+ /* 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->e_num, eh->e_max);
+ ext3_ext_binsearch_idx(tree, path + ppos, block);
+ path[ppos].p_block = path[ppos].p_idx->e_leaf;
+ path[ppos].p_depth = i;
+ path[ppos].p_ext = NULL;
+
+ bh = sb_bread(tree->inode->i_sb, path[ppos].p_block);
+ if (!bh) {
+ ext3_ext_drop_refs(path);
+ kfree(path);
+ return ERR_PTR(-EIO);
+ }
+ eh = EXT_BLOCK_HDR(bh);
+ ppos++;
+ EXT_ASSERT(ppos <= depth);
+ path[ppos].p_bh = bh;
+ path[ppos].p_hdr = eh;
+ i--;
+ }
+
+ path[ppos].p_depth = i;
+ path[ppos].p_hdr = eh;
+ path[ppos].p_ext = NULL;
+
+ /* find extent */
+ ext3_ext_binsearch(tree, path + ppos, block);
+
+ ext3_ext_show_path(tree, path);
+
+ return path;
+}
+
+/*
+ * 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->e_block);
+ len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
+ if (logical > curp->p_idx->e_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->e_block = logical;
+ ix->e_leaf = ptr;
+ curp->p_hdr->e_num++;
+
+ EXT_ASSERT(curp->p_hdr->e_num <= curp->p_hdr->e_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].e_block;
+ ext_debug(tree, "leaf will be splitted."
+ " next leaf starts at %d\n",
+ (int)border);
+ } else {
+ border = newext->e_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->e_num = 0;
+ neh->e_max = ext3_ext_space_block(tree);
+ neh->e_magic = EXT3_EXT_MAGIC;
+ neh->e_depth = 0;
+ ex = EXT_FIRST_EXTENT(neh);
+
+ /* move remain of path[depth] to the new leaf */
+ EXT_ASSERT(path[depth].p_hdr->e_num == path[depth].p_hdr->e_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\n",
+ path[depth].p_ext->e_block,
+ path[depth].p_ext->e_start,
+ path[depth].p_ext->e_num);
+ memmove(ex++, path[depth].p_ext++,
+ sizeof(struct ext3_extent));
+ neh->e_num++;
+ m++;
+ }
+ mark_buffer_uptodate(bh, 1);
+ 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)))
+ goto cleanup;
+ path[depth].p_hdr->e_num -= m;
+ if ((err = ext3_ext_dirty(handle, tree, path)))
+ 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->e_num = 1;
+ neh->e_magic = EXT3_EXT_MAGIC;
+ neh->e_max = ext3_ext_space_block_idx(tree);
+ neh->e_depth = depth - i;
+ fidx = EXT_FIRST_INDEX(neh);
+ fidx->e_block = border;
+ fidx->e_leaf = oldblock;
+
+ 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\n",
+ i, path[i].p_idx->e_block,
+ path[i].p_idx->e_leaf);
+ memmove(++fidx, path[i].p_idx++,
+ sizeof(struct ext3_extent_idx));
+ neh->e_num++;
+ EXT_ASSERT(neh->e_num <= neh->e_max);
+ m++;
+ }
+ mark_buffer_uptodate(bh, 1);
+ 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->e_num -= 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 e_max right way */
+ if (EXT_DEPTH(tree))
+ neh->e_max = ext3_ext_space_block_idx(tree);
+ else
+ neh->e_max = ext3_ext_space_block(tree);
+ neh->e_magic = EXT3_EXT_MAGIC;
+ mark_buffer_uptodate(bh, 1);
+ 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->e_magic = EXT3_EXT_MAGIC;
+ curp->p_hdr->e_max = ext3_ext_space_root_idx(tree);
+ curp->p_hdr->e_num = 1;
+ curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
+ /* FIXME: it works, but actually path[0] can be index */
+ curp->p_idx->e_block = EXT_FIRST_EXTENT(path[0].p_hdr)->e_block;
+ curp->p_idx->e_leaf = newblock;
+
+ neh = EXT_ROOT_HDR(tree);
+ fidx = EXT_FIRST_INDEX(neh);
+ ext_debug(tree, "new root: num %d(%d), lblock %d, ptr %d\n",
+ neh->e_num, neh->e_max, fidx->e_block, fidx->e_leaf);
+
+ neh->e_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->e_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->e_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->e_num == path[depth].p_hdr->e_max) {
+ /* now we need split */
+ goto repeat;
+ }
+ }
+
+ if (err)
+ return err;
+
+ return 0;
+}
+
+/*
+ * returns allocated block in subsequent extent or 0xffffffff
+ * 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 0xffffffff;
+
+ /* 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].e_block;
+ } else {
+ /* index */
+ if (path[depth].p_idx !=
+ EXT_LAST_INDEX(path[depth].p_hdr))
+ return path[depth].p_idx[1].e_block;
+ }
+ depth--; + }
+
+ return 0xffffffff;
+}
+
+/*
+ * returns first allocated block from next leaf or 0xffffffff
+ */
+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 0xffffffff;
+
+ /* 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].e_block;
+ depth--;
+ }
+
+ return 0xffffffff;
+}
+
+/*
+ * 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->e_block;
+ if ((err = ext3_ext_get_access(handle, tree, path + k)))
+ return err;
+ path[k].p_idx->e_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->e_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->e_block + ex1->e_num != ex2->e_block)
+ return 0;
+
+#ifdef AGRESSIVE_TEST
+ if (ex1->e_num >= 4)
+ return 0;
+#endif
+
+ if (!tree->mergable)
+ return 1;
+
+ return tree->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;
+
+ depth = EXT_DEPTH(tree);
+ ex = path[depth].p_ext;
+
+ /* 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->e_num, ex->e_block, ex->e_num,
+ ex->e_start);
+ if ((err = ext3_ext_get_access(handle, tree, path + depth)))
+ return err;
+ ex->e_num += newext->e_num;
+ err = ext3_ext_dirty(handle, tree, path + depth);
+ return err;
+ }
+
+repeat:
+ depth = EXT_DEPTH(tree);
+ eh = path[depth].p_hdr;
+ if (eh->e_num < eh->e_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->e_block > fex->e_block && next != 0xffffffff) {
+ 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->e_num < eh->e_max) {
+ ext_debug(tree, "next leaf isnt full(%d)\n",
+ eh->e_num);
+ path = npath;
+ goto repeat;
+ }
+ ext_debug(tree, "next leaf hasno free space(%d,%d)\n",
+ eh->e_num, eh->e_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->e_block, newext->e_start,
+ newext->e_num);
+ path[depth].p_ext = EXT_FIRST_EXTENT(eh);
+ } else if (newext->e_block > nearex->e_block) {
+ EXT_ASSERT(newext->e_block != nearex->e_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->e_block, newext->e_start,
+ newext->e_num,
+ nearex, len, nearex + 1, nearex + 2);
+ memmove(nearex + 2, nearex + 1, len);
+ }
+ path[depth].p_ext = nearex + 1;
+ } else {
+ EXT_ASSERT(newext->e_block != nearex->e_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->e_block, newext->e_start, newext->e_num,
+ nearex, len, nearex + 1, nearex + 2);
+ memmove(nearex + 1, nearex, len);
+ path[depth].p_ext = nearex;
+ }+
+ eh->e_num++;
+ nearex = path[depth].p_ext;
+ nearex->e_block = newext->e_block;
+ nearex->e_start = newext->e_start;
+ nearex->e_num = newext->e_num;
+
+ /* 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);
+ }
+
+ 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_extent *ex, cbex;
+ unsigned long next, start = 0, end = 0;
+ int depth, exists, err = 0;
+
+ EXT_ASSERT(tree);
+ EXT_ASSERT(func);
+ EXT_ASSERT(tree->inode);
+ EXT_ASSERT(tree->root);
+
+ while (num > 0 && block != 0xfffffffff) {
+ /* find extent for this block */
+ path = ext3_ext_find_extent(tree, block, path);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ break;
+ }
+
+ depth = EXT_DEPTH(tree);
+ 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 - 1;
+ } else if (ex->e_block > block) {
+ /* need to allocate space before found extent */
+ start = block;
+ end = ex->e_block - 1;
+ if (block + num - 1 < end)
+ end = block + num - 1;
+ } else if (block >= ex->e_block + ex->e_num) {
+ /* need to allocate space after found extent */
+ start = block;
+ end = block + num - 1;
+ if (end >= next)
+ end = next - 1;
+ } else if (block >= ex->e_block) {
+ /*
+ * some part of requested space is covered
+ * by found extent+ */
+ start = block;
+ end = ex->e_block + ex->e_num - 1;
+ if (block + num - 1 < end)
+ end = block + num - 1;
+ exists = 1;
+ } else {
+ BUG();
+ }
+
+ if (!exists) {
+ cbex.e_block = start;
+ cbex.e_num = end - start + 1;
+ cbex.e_start = 0;
+ } else
+ cbex = *ex;
+
+ err = func(tree, path, &cbex, exists);
+ if (err < 0)
+ break;
+
+ if (err == EXT_BREAK) {
+ err = 0;
+ break;
+ }
+
+ if (EXT_DEPTH(tree) != depth) {
+ /* depth was changed. we have to realloc path */
+ ext3_ext_drop_refs(path);
+ kfree(path);
+ path = NULL;
+ }
+
+ block += cbex.e_num;
+ num -= cbex.e_num;
+ }
+
+ if (path) {
+ ext3_ext_drop_refs(path);
+ kfree(path);
+ }
+
+ return err;
+}
+
+static inline void
+ext3_ext_invalidate_cache(struct ext3_extents_tree *tree)
+{
+ if (tree->cex)
+ tree->cex->e_num = 0;
+}
+
+static inline void
+ext3_ext_put_in_cache(struct ext3_extents_tree *tree, struct ext3_extent *ex)
+{
+ if (tree->cex) {
+ EXT_ASSERT(ex);
+ EXT_ASSERT(ex->e_num);
+ tree->cex->e_block = ex->e_block;
+ tree->cex->e_start = ex->e_start;
+ tree->cex->e_num = ex->e_num;
+ }
+}
+
+/*
+ * 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);
+ struct ext3_extent *ex, gex;
+
+ if (!tree->cex)
+ return;
+
+ ex = path[depth].p_ext;
+ if (ex == NULL) {
+ /* there is no extent yet, so gap is [0;-] */
+ gex.e_block = 0;
+ gex.e_num = 0xffffffff;
+ ext_debug(tree, "cache gap(whole file):");
+ } else if (block < ex->e_block) {
+ gex.e_block = block;
+ gex.e_num = ex->e_block - block;
+ ext_debug(tree, "cache gap(before): %lu [%lu:%lu]",
+ (unsigned long) block,
+ (unsigned long) ex->e_block,
+ (unsigned long) ex->e_num);
+ } else if (block >= ex->e_block + ex->e_num) {
+ gex.e_block = ex->e_block + ex->e_num;
+ gex.e_num = ext3_ext_next_allocated_block(path);
+ ext_debug(tree, "cache gap(after): [%lu:%lu] %lu",
+ (unsigned long) ex->e_block,
+ (unsigned long) ex->e_num,
+ (unsigned long) block);
+ EXT_ASSERT(gex.e_num > gex.e_block);
+ gex.e_num = gex.e_num - gex.e_block;
+ } else {
+ BUG();
+ }
+
+ ext_debug(tree, " -> %lu:%lu\n", (unsigned long) gex.e_block,
+ (unsigned long) gex.e_num);
+ gex.e_start = 0xffffffff;
+ ext3_ext_put_in_cache(tree, &gex);
+}
+
+static inline int
+ext3_ext_in_cache(struct ext3_extents_tree *tree, unsigned long block,
+ struct ext3_extent *ex)
+{
+ struct ext3_extent *cex = tree->cex;
+
+ /* is there cache storage at all? */
+ if (!cex)
+ return 0;
+
+ /* has cache valid data? */
+ if (cex->e_num == 0)
+ return 0;
+
+ if (block >= cex->e_block && block < cex->e_block + cex->e_num) {
+ ex->e_block = cex->e_block;
+ ex->e_start = cex->e_start;
+ ex->e_num = cex->e_num;
+ ext_debug(tree, "%lu cached by %lu:%lu:%lu\n",
+ (unsigned long) block,
+ (unsigned long) ex->e_block,
+ (unsigned long) ex->e_num,
+ (unsigned long) ex->e_start);
+ return 1;
+ }
+
+ /* not in cache */
+ return 0;
+}+
+/*
+ * 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->e_num);
+ if ((err = ext3_ext_get_access(handle, tree, path)))
+ return err;
+ path->p_hdr->e_num--;
+ 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->e_leaf);
+ bh = sb_get_hash_table(tree->inode->i_sb, path->p_idx->e_leaf);
+ ext3_forget(handle, 0, tree->inode, bh, path->p_idx->e_leaf);
+ ext3_free_blocks(handle, tree->inode, path->p_idx->e_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->e_num < path[depth].p_hdr->e_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->e_block + ex->e_num - 1);
+ EXT_ASSERT(ex->e_block < start);
+
+ /* calculate tail extent */
+ tex.e_block = end + 1;
+ EXT_ASSERT(tex.e_block < ex->e_block + ex->e_num);
+ tex.e_num = ex->e_block + ex->e_num - tex.e_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->e_num = start - ex->e_block;
+ err = ext3_ext_dirty(handle, tree, path + depth);
+ if (err)
+ return err;
+
+ /* FIXME: some callback to free underlying resource
+ * and correct e_start? */
+ ext_debug(tree, "split extent: head %u:%u, tail %u:%u\n",
+ ex->e_block, ex->e_num, tex.e_block, tex.e_num);
+
+ npath = ext3_ext_find_extent(tree, ex->e_block, NULL);
+ if (IS_ERR(npath))
+ return PTR_ERR(npath);
+ depth = EXT_DEPTH(tree);
+ EXT_ASSERT(npath[depth].p_ext->e_block == ex->e_block);
+ EXT_ASSERT(npath[depth].p_ext->e_num == ex->e_num);
+
+ 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->e_num <= eh->e_max);
+ EXT_ASSERT(eh->e_magic == EXT3_EXT_MAGIC);
+
+ /* find where to start removing */
+ le = ex = EXT_LAST_EXTENT(eh);
+ while (ex != EXT_FIRST_EXTENT(eh)) {+ if (ex->e_block <= end)
+ break;
+ ex--;
+ }
+
+ if (start > ex->e_block && end < ex->e_block + ex->e_num - 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->e_block + ex->e_num > start) {
+ ext_debug(tree, "remove ext %u:%u\n", ex->e_block, ex->e_num);
+ path[depth].p_ext = ex;
+
+ a = ex->e_block > start ? ex->e_block : start;
+ b = ex->e_block + ex->e_num - 1 < end ?
+ ex->e_block + ex->e_num - 1 : end;
+
+ ext_debug(tree, " border %u:%u\n", a, b);
+
+ if (a != ex->e_block && b != ex->e_block + ex->e_num - 1) {
+ block = 0;
+ num = 0;
+ BUG();
+ } else if (a != ex->e_block) {
+ /* remove tail of the extent */
+ block = ex->e_block;
+ num = a - block;
+ } else if (b != ex->e_block + ex->e_num - 1) {
+ /* remove head of the extent */
+ block = a;
+ num = b - a;
+ } else {
+ /* remove whole extent: excelent! */
+ block = ex->e_block;
+ num = 0;
+ EXT_ASSERT(a == ex->e_block &&
+ b == ex->e_block + ex->e_num - 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->remove_extent_credits)
+ credits += tree->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->remove_extent)
+ err = tree->remove_extent(tree, ex, a, b);
+ if (err)
+ goto out;
+
+ if (num == 0) {+ /* this extent is removed entirely mark slot unused */
+ ex->e_start = 0;
+ eh->e_num--;
+ fu = ex;
+ }
+
+ ex->e_block = block;
+ ex->e_num = num;
+
+ err = ext3_ext_dirty(handle, tree, path + depth);
+ if (err)
+ goto out;
+
+ ext_debug(tree, "new extent: %u:%u:%u\n",
+ ex->e_block, ex->e_num, ex->e_start);
+ ex--;
+ }
+
+ if (fu) {
+ /* reuse unused slots */
+ while (lu < le) {
+ if (lu->e_start) {
+ *fu = *lu;
+ lu->e_start = 0;
+ fu++;
+ }
+ lu++;
+ }
+ }
+
+ if (correct_index && eh->e_num)
+ 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->e_num == 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->e_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->e_num == 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, "ext3_ext_remove_space",
+ "Can't allocate path array");
+ ext3_journal_stop(handle, inode);
+ 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->e_num <= path[i].p_hdr->e_max);
+ EXT_ASSERT(path[i].p_hdr->e_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->e_num + 1;
+ ext_debug(tree, "init index ptr: hdr 0x%p, num %d\n",
+ path[i].p_hdr, path[i].p_hdr->e_num);
+ } 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->e_leaf);
+ memset(path + i + 1, 0, sizeof(*path));
+ path[i+1].p_bh = sb_bread(sb, path[i].p_idx->e_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->e_num;
+ i++;
+ } else {
+ /* we finish processing this index, go up */
+ if (path[i].p_hdr->e_num == 0 && i > 0) {
+ /* index is empty, remove it
+ * handle must be already prepared by the
+ * truncate_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->e_num == 0) {
+ /*
+ * truncate to zero freed all the tree
+ * so, we need to correct e_depth
+ */
+ err = ext3_ext_get_access(handle, tree, path);
+ if (err == 0) {
+ EXT_ROOT_HDR(tree)->e_depth = 0;
+ err = ext3_ext_dirty(handle, tree, path);
+ }
+ }
+
+ kfree(path);
+ ext3_journal_stop(handle, inode);
+
+ return err;
+}
+
+/*
+ * 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;
+ ext3_mark_inode_dirty(handle, inode);
+ return 0;
+}
+
+static int ext3_ext_mergable(struct ext3_extent *ex1,
+ struct ext3_extent *ex2)
+{
+ if (ex1->e_start + ex1->e_num == ex2->e_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 = 3; /* bitmap + group desc + sb */
+
+#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);
+
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ if (from >= ex->e_block && to == ex->e_block + ex->e_num - 1) {
+ /* tail removal */
+ unsigned long num, start;
+ num = ex->e_block + ex->e_num - from;
+ start = ex->e_start + ex->e_num - num;
+ ext_debug(tree, "free last %lu blocks starting %lu\n",
+ num, start);
+ ext3_free_blocks(handle, tree->inode, start, num);+ } else if (from == ex->e_block && to <= ex->e_block + ex->e_num - 1) {
+ printk("strange request: removal %lu-%lu from %u:%u\n",
+ from, to, ex->e_block, ex->e_num);
+ } else {
+ printk("strange request: removal(2) %lu-%lu from %u:%u\n",
+ from, to, ex->e_block, ex->e_num);
+ }
+ ext3_journal_stop(handle, tree->inode);
+ return 0;
+}
+
+static int ext3_ext_find_goal(struct inode *inode,
+ struct ext3_ext_path *path)
+{
+ struct ext3_inode_info *ei = EXT3_I(inode);
+ unsigned long bg_start;
+ unsigned long colour;
+ int depth;
+
+ if (path) {
+ depth = path->p_depth;
+ /* try to find previous block */
+ if (path[depth].p_ext)
+ return path[depth].p_ext->e_start +
+ path[depth].p_ext->e_num;
+
+ /* 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;
+}
+
+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->e_start);
+ EXT_ASSERT(ex->e_num);
+
+ /* reuse block from the extent to order data/metadata */
+ newblock = ex->e_start++;
+ ex->e_num--;
+ if (ex->e_num == 0) {
+ ex->e_num = 1;
+ /* allocate new block for the extent */
+ goal = ext3_ext_find_goal(inode, path);
+ ex->e_start = ext3_new_block(handle, inode, goal, 0, 0, err);
+ if (ex->e_start == 0) {
+ /* error occured: restore old extent */
+ ex->e_start = newblock;
+ return 0;
+ }
+ }
+ return newblock;
+}
+
+static 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->get_write_access = ext3_get_inode_write_access;
+ tree->mark_buffer_dirty = ext3_mark_buffer_dirty;
+ tree->mergable = ext3_ext_mergable;
+ tree->new_block = ext3_new_block_cb;
+ tree->remove_extent = ext3_remove_blocks;
+ tree->remove_extent_credits = ext3_remove_blocks_credits;
+ tree->buffer = (void *) inode;
+ tree->buffer_len = sizeof(EXT3_I(inode)->i_data);
+ tree->cex = (struct ext3_extent *) &EXT3_I(inode)->i_cached_extent;
+}
+
+#if EXT3_MULTIBLOCK_ALLOCATOR
+static int
+ext3_ext_new_extent_cb(struct ext3_extents_tree *tree,
+ struct ext3_ext_path *path,
+ struct ext3_extent *newex, int exist)
+{
+ struct inode *inode = tree->inode;
+ int count, err, goal;
+ loff_t new_i_size;
+ handle_t *handle;
+ unsigned long pblock;
+
+ if (exist)
+ return EXT_CONTINUE;
+
+ count = ext3_ext_calc_credits_for_insert(tree, path);
+ handle = ext3_journal_start(inode, count + EXT3_ALLOC_NEEDED + 1);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ goal = ext3_ext_find_goal(inode, path);
+ count = newex->e_num;
+ pblock = ext3_new_blocks(handle, inode, &count, goal, &err);
+ EXT_ASSERT(count <= newex->e_num);
+ /* FIXME: error handling here */
+ EXT_ASSERT(err == 0);
+
+ /* insert new extent */
+ newex->e_start = pblock;
+ newex->e_num = count;
+ err = ext3_ext_insert_extent(handle, tree, path, newex);
+ if (err)
+ goto out;
+
+
+ /* correct on-disk inode size */
+ if (newex->e_num > 0) {
+ new_i_size = (loff_t) newex->e_block + newex->e_num;
+ new_i_size = new_i_size << inode->i_blkbits;
+ if (new_i_size > EXT3_I(inode)->i_disksize) {
+ EXT3_I(inode)->i_disksize = new_i_size;
+ err = ext3_mark_inode_dirty(handle, inode);
+ }
+ }
+
+out:
+ ext3_journal_stop(handle, inode);
+ return err;
+}
+
+
+int ext3_ext_allocate_nblocks(struct inode *inode, unsigned long block,
+ unsigned long num)
+{
+ struct ext3_extents_tree tree;+ int err;
+
+ ext3_init_tree_desc(&tree, inode);
+ ext_debug(&tree, "blocks %lu-%lu requested for inode %u\n",
+ block, block + num,(unsigned) inode->i_ino);
+ down_write(&EXT3_I(inode)->truncate_sem);
+ err = ext3_ext_walk_space(&tree, block, num, ext3_ext_new_extent_cb);
+ ext3_ext_invalidate_cache(&tree);
+ up_write(&EXT3_I(inode)->truncate_sem);
+
+ return err;
+}
+#endif
+
+int ext3_ext_get_block(handle_t *handle, struct inode *inode,
+ long iblock, struct buffer_head *bh_result, int create)
+{
+ 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_bit(BH_New, &bh_result->b_state);
+ ext3_init_tree_desc(&tree, inode);
+ ext_debug(&tree, "block %d requested for inode %u\n",
+ (int) iblock, (unsigned) inode->i_ino);
+ down_write(&EXT3_I(inode)->truncate_sem);
+
+ /* check in cache */
+ if (ext3_ext_in_cache(&tree, iblock, &newex)) {
+ if (newex.e_start == 0xffffffff && !create) {
+ /* block isn't allocated yet and
+ * user don't want to allocate it */
+ goto out2;
+ } else if (newex.e_start) {
+ /* block is already allocated */
+ newblock = iblock - newex.e_block + newex.e_start;
+ goto out;
+ }
+ }
+
+ /* find extent for this block */
+ path = ext3_ext_find_extent(&tree, iblock, NULL);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ 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->e_block && iblock < ex->e_block + ex->e_num) {
+ newblock = iblock - ex->e_block + ex->e_start;
+ ext_debug(&tree, "%d fit into %d:%d -> %d\n",
+ (int) iblock, ex->e_block, ex->e_num,
+ newblock);
+ ext3_ext_put_in_cache(&tree, ex);
+ 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);
+ newblock = ext3_new_block(handle, inode, goal, 0, 0, &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.e_block = iblock;
+ newex.e_start = newblock;
+ newex.e_num = 1;
+ err = ext3_ext_insert_extent(handle, &tree, path, &newex);
+ if (err)
+ goto out2;
+
+ if (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.e_start;
+ set_bit(BH_New, &bh_result->b_state);
+
+ ext3_ext_put_in_cache(&tree, &newex);
+out:
+ ext3_ext_show_leaf(&tree, path);
+ set_bit(BH_Mapped, &bh_result->b_state);
+ bh_result->b_dev = inode->i_sb->s_dev;
+ bh_result->b_blocknr = newblock;
+out2:
+ if (path) {
+ ext3_ext_drop_refs(path);
+ kfree(path);
+ }
+ up_write(&EXT3_I(inode)->truncate_sem);
+
+ return err;
+}
+
+void ext3_ext_truncate(struct inode * inode)
+{
+ 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))
+ return;
+
+ ext3_block_truncate_page(handle, mapping, inode->i_size);
++ down_write(&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, 0xffffffff);
+
+ /* 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_write(&EXT3_I(inode)->truncate_sem);
+ ext3_journal_stop(handle, inode);
+}
+
+/*
+ * 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);
+}
+
+static int
+ext3_ext_store_extent_cb(struct ext3_extents_tree *tree,
+ struct ext3_ext_path *path,
+ struct ext3_extent *newex, int exist)
+{
+ struct ext3_extent_buf *buf = (struct ext3_extent_buf *) tree->private;
+
+ if (!exist)
+ 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_extent *ex, int exist)
+{
+ struct ext3_extent_tree_stats *buf =
+ (struct ext3_extent_tree_stats *) tree->private;
+ int depth;
+
+ if (!exist)
+ 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 (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;
+ err = ext3_ext_walk_space(&tree, buf.start, 0xffffffff,
+ ext3_ext_store_extent_cb);
+ 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);
+ buf.depth = EXT_DEPTH(&tree);
+ buf.extents_num = 0;
+ buf.leaf_num = 0;
+ tree.private = &buf;
+ err = ext3_ext_walk_space(&tree, 0, 0xffffffff,
+ ext3_ext_collect_stats_cb);
+ 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);
+ err = EXT_DEPTH(&tree);
+ }
+
+ return err;
+}
+
Index: linux-2.4.24/fs/ext3/ialloc.c
===================================================================
--- linux-2.4.24.orig/fs/ext3/ialloc.c 2004-01-14 02:58:45.000000000 +0300
+++ linux-2.4.24/fs/ext3/ialloc.c 2004-01-26 23:17:19.000000000 +0300
@@ -592,11 +592,13 @@
iloc.bh = NULL;
goto fail;
}
+ if (test_opt(sb, EXTENTS)) {
+ EXT3_I(inode)->i_flags |= EXT3_EXTENTS_FL;
+ ext3_extents_initialize_blockmap(handle, inode);
+ }
err = ext3_mark_iloc_dirty(handle, inode, &iloc);
if (err) goto fail;
-
-
unlock_super (sb);
if(DQUOT_ALLOC_INODE(inode)) {
DQUOT_DROP(inode);
Index: linux-2.4.24/fs/ext3/inode.c
===================================================================
--- linux-2.4.24.orig/fs/ext3/inode.c 2004-01-14 02:58:45.000000000 +0300
+++ linux-2.4.24/fs/ext3/inode.c 2004-01-26 23:17:19.000000000 +0300
@@ -848,6 +848,15 @@
goto reread;
}
+static inline int
+ext3_get_block_wrap(handle_t *handle, struct inode *inode, long block,
+ struct buffer_head *bh, int create)
+{
+ if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
+ return ext3_ext_get_block(handle, inode, block, bh, create);
+ return ext3_get_block_handle(handle, inode, block, bh, create);
+}
+
/*
* The BKL is not held on entry here.
*/
@@ -861,7 +870,7 @@
handle = ext3_journal_current_handle();
J_ASSERT(handle != 0);
}
- ret = ext3_get_block_handle(handle, inode, iblock, bh_result, create);
+ ret = ext3_get_block_wrap(handle, inode, iblock, bh_result, create);
return ret;
}
@@ -879,7 +888,7 @@
dummy.b_state = 0; dummy.b_blocknr = -1000;
buffer_trace_init(&dummy.b_history);
- *errp = ext3_get_block_handle(handle, inode, block, &dummy, create);
+ *errp = ext3_get_block_wrap(handle, inode, block, &dummy, create);
if (!*errp && buffer_mapped(&dummy)) {
struct buffer_head *bh;
bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
@@ -1403,7 +1412,7 @@
* 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,
+int ext3_block_truncate_page(handle_t *handle,
struct address_space *mapping, loff_t from)
{
unsigned long index = from >> PAGE_CACHE_SHIFT;
@@ -1888,6 +1897,9 @@
ext3_discard_prealloc(inode);
+ if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
+ return ext3_ext_truncate(inode);
+
handle = start_transaction(inode);
if (IS_ERR(handle))
return; /* AKPM: return what? */
@@ -2536,6 +2548,9 @@
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
@@ -2972,7 +2987,7 @@
/* alloc blocks one by one */
for (i = 0; i < nblocks; i++) {
- ret = ext3_get_block_handle(handle, inode, blocks[i],
+ ret = ext3_get_block_wrap(handle, inode, blocks[i],
&bh_tmp, 1);
if (ret)
break;
@@ -3048,7 +3063,7 @@
if (blocks[i] != 0)
continue;
- rc = ext3_get_block_handle(handle, inode, iblock, &bh, 1);
+ rc = ext3_get_block_wrap(handle, inode, iblock, &bh, 1);
if (rc) {
printk(KERN_INFO "ext3_map_inode_page: error %d "
"allocating block %ld\n", rc, iblock);
Index: linux-2.4.24/fs/ext3/Makefile
===================================================================
--- linux-2.4.24.orig/fs/ext3/Makefile 2004-01-14 02:58:45.000000000 +0300
+++ linux-2.4.24/fs/ext3/Makefile 2004-01-26 23:17:19.000000000 +0300
@@ -13,7 +13,7 @@
obj-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 ext3-exports.o \
- xattr_trusted.o
+ xattr_trusted.o extents.o
obj-m := $(O_TARGET)
export-objs += xattr.o
Index: linux-2.4.24/fs/ext3/super.c
===================================================================
--- linux-2.4.24.orig/fs/ext3/super.c 2004-01-14 02:58:45.000000000 +0300+++ linux-2.4.24/fs/ext3/super.c 2004-01-26 23:17:19.000000000 +0300
@@ -530,6 +530,7 @@
int i;
J_ASSERT(sbi->s_delete_inodes == 0);
+ ext3_ext_release(sb);
ext3_xattr_put_super(sb);
journal_destroy(sbi->s_journal);
if (!(sb->s_flags & MS_RDONLY)) {
@@ -702,6 +703,10 @@
return 0;
}
}
+ else if (!strcmp (this_char, "extents"))
+ set_opt (*mount_options, EXTENTS);
+ else if (!strcmp (this_char, "extdebug"))
+ set_opt (*mount_options, EXTDEBUG);
else if (!strcmp (this_char, "grpid") ||
!strcmp (this_char, "bsdgroups"))
set_opt (*mount_options, GRPID);
@@ -1392,6 +1397,8 @@
test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
"writeback");
+ ext3_ext_init(sb);
+
return sb;
failed_mount3:
Index: linux-2.4.24/fs/ext3/ioctl.c
===================================================================
--- linux-2.4.24.orig/fs/ext3/ioctl.c 2004-01-14 02:58:42.000000000 +0300
+++ linux-2.4.24/fs/ext3/ioctl.c 2004-01-26 23:17:19.000000000 +0300
@@ -174,6 +174,10 @@
return ret;
}
#endif
+ 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);
default:
return -ENOTTY;
}
Index: linux-2.4.24/include/linux/ext3_fs.h
===================================================================
--- linux-2.4.24.orig/include/linux/ext3_fs.h 2004-01-14 02:58:45.000000000 +0300
+++ linux-2.4.24/include/linux/ext3_fs.h 2004-01-26 23:17:19.000000000 +0300
@@ -184,6 +184,7 @@
#define EXT3_IMAGIC_FL 0x00002000 /* AFS directory */
#define EXT3_JOURNAL_DATA_FL 0x00004000 /* file data should be journaled */
#define EXT3_RESERVED_FL 0x80000000 /* reserved for ext3 lib */
+#define EXT3_EXTENTS_FL 0x00080000 /* Inode uses extents */
#define EXT3_FL_USER_VISIBLE 0x00005FFF /* User visible flags */
#define EXT3_FL_USER_MODIFIABLE 0x000000FF /* User modifiable flags */
@@ -208,6 +209,9 @@
#ifdef CONFIG_JBD_DEBUG
#define EXT3_IOC_WAIT_FOR_READONLY _IOR('f', 99, long)
#endif
+#define EXT3_IOC_GET_EXTENTS _IOR('f', 5, long)
+#define EXT3_IOC_GET_TREE_DEPTH _IOR('f', 6, long)
+#define EXT3_IOC_GET_TREE_STATS _IOR('f', 7, long)
/*
* Structure of an inode on the disk
@@ -327,6 +331,8 @@
#define EXT3_MOUNT_IOPEN 0x8000 /* Allow access via iopen */
#define EXT3_MOUNT_IOPEN_NOPRIV 0x10000 /* Make iopen world-readable */
#define EXT3_MOUNT_ASYNCDEL 0x20000 /* Delayed deletion */+#define EXT3_MOUNT_EXTENTS 0x100000/* Extents support */
+#define EXT3_MOUNT_EXTDEBUG 0x200000/* Extents debug */
/* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
#ifndef _LINUX_EXT2_FS_H
@@ -688,6 +694,7 @@
extern unsigned long ext3_count_free (struct buffer_head *, unsigned);
/* inode.c */
+extern int ext3_block_truncate_page(handle_t *, 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 *);
@@ -769,6 +776,14 @@
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);
+extern void ext3_ext_truncate(struct inode *);
+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 *);
#endif /* __KERNEL__ */
Index: linux-2.4.24/include/linux/ext3_extents.h
===================================================================
--- linux-2.4.24.orig/include/linux/ext3_extents.h 2003-01-30 13:24:37.000000000 +0300
+++ linux-2.4.24/include/linux/ext3_extents.h 2004-01-26 23:17:19.000000000 +0300
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) 2003 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 2 /* block bitmap + group descriptor */
+
+/*
+ * 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 e_block; /* first logical block extent covers */
+ __u32 e_start; /* first physical block extents lives */
+ __u32 e_num; /* number of blocks covered by extent */
+};
+
+/*
+ * this is index on-disk structure
+ * it's used at all the levels, but the bottom
+ */
+struct ext3_extent_idx {
+ __u32 e_block; /* index covers logical blocks from 'block' */
+ __u32 e_leaf; /* pointer to the physical block of the next *
+ * level. leaf or next index could bet here */
+};
+
+/*
+ * each block (leaves and indexes), even inode-stored has header
+ */
+struct ext3_extent_header {
+ __u16 e_magic; /* probably will support different formats */
+ __u16 e_num; /* number of valid entries */
+ __u16 e_max; /* capacity of store in entries */
+ __u16 e_depth; /* has tree real underlaying blocks? */
+};
+
+#define EXT3_EXT_MAGIC 0xf301
+
+/*
+ * 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
+ */
+
+
+/*
+ * ext3_extents_tree is used to pass initial information
+ * to top-level extents API
+ */
+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_extent *cex;/* last found extent */
+ 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_extent *, int);
+
+#define EXT_CONTINUE 0
+#define EXT_BREAK 1
+
+
+#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->e_num < (__path__)->p_hdr->e_max)
+#define EXT_LAST_EXTENT(__hdr__) \
+ (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->e_num - 1)
+#define EXT_LAST_INDEX(__hdr__) \
+ (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->e_num - 1)
+#define EXT_MAX_EXTENT(__hdr__) \
+ (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->e_max - 1)
+#define EXT_MAX_INDEX(__hdr__) \
+ (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->e_max - 1)
+
+#define EXT_ROOT_HDR(tree) \
+ ((struct ext3_extent_header *) (tree)->root)
+#define EXT_BLOCK_HDR(bh) \
+ ((struct ext3_extent_header *) (bh)->b_data)
+#define EXT_DEPTH(_t_) \+ (((struct ext3_extent_header *)((_t_)->root))->e_depth)
+
+
+#define EXT_ASSERT(__x__) if (!(__x__)) BUG();
+
+
+/*
+ * 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 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 *);
+
+#endif /* _LINUX_EXT3_EXTENTS */
+
Index: linux-2.4.24/include/linux/ext3_fs_i.h
===================================================================
--- linux-2.4.24.orig/include/linux/ext3_fs_i.h 2004-01-24 19:30:22.000000000 +0300
+++ linux-2.4.24/include/linux/ext3_fs_i.h 2004-01-26 23:17:19.000000000 +0300
@@ -76,6 +76,8 @@
* by other means, so we have truncate_sem.
*/
struct rw_semaphore truncate_sem;
+
+ __u32 i_cached_extent[3];
};
#endif /* _LINUX_EXT3_FS_I */