--- /dev/null
+ fs/ext3/Makefile | 3
+ fs/ext3/extents.c | 1578 +++++++++++++++++++++++++++++++++++++++++++++
+ fs/ext3/ialloc.c | 4
+ fs/ext3/inode.c | 30
+ fs/ext3/super.c | 8
+ include/linux/ext3_fs.h | 18
+ include/linux/ext3_fs_i.h | 4
+ include/linux/ext3_fs_sb.h | 10
+ 8 files changed, 1647 insertions(+), 8 deletions(-)
+
+--- /dev/null 2003-01-30 13:24:37.000000000 +0300
++++ linux-2.4.18-chaos-alexey/fs/ext3/extents.c 2003-09-17 00:43:16.000000000 +0400
+@@ -0,0 +1,1578 @@
++/*
++ *
++ * linux/fs/ext3/extents.c
++ *
++ * Extents support for EXT3
++ *
++ * 07/08/2003 Alex Tomas <bzzz@tmi.comex.ru>
++ *
++ * TODO:
++ * - ext3*_error() should be used in some situations
++ * - find_goal() [to be tested and improved]
++ * - error handling
++ * - we could leak allocated block in some error cases
++ * - quick search for index/leaf in ext3_ext_find_extent()
++ * - tree reduction
++ * - cache last found extent
++ * - arch-independent
++ */
++
++#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>
++
++/*
++ * 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 EXT_DEBUG 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(inode,fmt,a...) \
++do { \
++ if (test_opt((inode)->i_sb, EXTDEBUG)) \
++ printk(fmt, ##a); \
++} while (0);
++#else
++#define ext_debug(inode,fmt,a...)
++#endif
++
++#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_num; /* number of valid entries */
++ __u16 e_max; /* capacity of store in entries */
++};
++
++/*
++ * 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;
++};
++
++#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_ASSERT(__x__) if (!(__x__)) BUG();
++
++/*
++ * could return:
++ * - EROFS
++ * - ENOMEM
++ */
++static int ext3_ext_get_access(handle_t *handle, struct inode *inode,
++ 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 0;
++}
++
++/*
++ * could return:
++ * - EROFS
++ * - ENOMEM
++ * - EIO
++ */
++static int ext3_ext_dirty(handle_t *handle, struct inode *inode,
++ 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_mark_inode_dirty(handle, inode);
++}
++
++static inline int ext3_ext_space_block(struct inode *inode)
++{
++ int size;
++
++ size = (inode->i_sb->s_blocksize - sizeof(struct ext3_extent_header))
++ / sizeof(struct ext3_extent);
++#ifdef AGRESSIVE_TEST
++ size = 6; /* FIXME: for debug, remove this line */
++#endif
++ return size;
++}
++
++static inline int ext3_ext_space_inode(struct inode *inode)
++{
++ int size;
++
++ size = (sizeof(EXT3_I(inode)->i_data) -
++ sizeof(struct ext3_extent_header))
++ / sizeof(struct ext3_extent);
++#ifdef AGRESSIVE_TEST
++ size = 3; /* FIXME: for debug, remove this line */
++#endif
++ return size;
++}
++
++static inline int ext3_ext_space_inode_idx(struct inode *inode)
++{
++ int size;
++
++ size = (sizeof(EXT3_I(inode)->i_data) -
++ sizeof(struct ext3_extent_header))
++ / sizeof(struct ext3_extent_idx);
++#ifdef AGRESSIVE_TEST
++ size = 4; /* FIXME: for debug, remove this line */
++#endif
++ return size;
++}
++
++static void ext3_ext_show_path(struct inode *inode, struct ext3_ext_path *path)
++{
++ int k, l = path->p_depth;
++
++ ext_debug(inode, "path:");
++ for (k = 0; k <= l; k++, path++) {
++ if (path->p_idx) {
++ ext_debug(inode, " %d->%d", path->p_idx->e_block,
++ path->p_idx->e_leaf);
++ } else if (path->p_ext) {
++ ext_debug(inode, " %d:%d:%d",
++ path->p_ext->e_block,
++ path->p_ext->e_start,
++ path->p_ext->e_num);
++ } else
++ ext_debug(inode, " []");
++ }
++ ext_debug(inode, "\n");
++}
++
++static void ext3_ext_show_leaf(struct inode *inode, struct ext3_ext_path *path)
++{
++ int depth = EXT3_I(inode)->i_depth;
++ struct ext3_extent_header *eh = path[depth].p_hdr;
++ struct ext3_extent *ex = EXT_FIRST_EXTENT(eh);
++ int i;
++
++ for (i = 0; i < eh->e_num; i++, ex++) {
++ ext_debug(inode, "%d:%d:%d ",
++ ex->e_block, ex->e_start, ex->e_num);
++ }
++ ext_debug(inode, "\n");
++}
++
++static void ext3_ext_drop_refs(struct inode *inode, 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;
++ }
++}
++
++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 - 1;
++
++ /* 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 struct ext3_ext_path *
++ext3_ext_find_extent(struct inode *inode, int block, struct ext3_ext_path *path)
++{
++ struct ext3_inode_info *ei = EXT3_I(inode);
++ struct ext3_extent_header *eh = (void *) ei->i_data;
++ struct ext3_extent_idx *ix;
++ struct buffer_head *bh;
++ struct ext3_extent *ex;
++ int depth, i, k, ppos = 0;
++
++ eh = (struct ext3_extent_header *) ei->i_data;
++
++ /* initialize capacity of leaf in inode for first time */
++ if (eh->e_max == 0)
++ eh->e_max = ext3_ext_space_inode(inode);
++ i = depth = ei->i_depth;
++ 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));
++
++ /* walk through the tree */
++ while (i) {
++ ext_debug(inode, "depth %d: num %d, max %d\n",
++ ppos, eh->e_num, eh->e_max);
++ ix = EXT_FIRST_INDEX(eh);
++ if (eh->e_num)
++ path[ppos].p_idx = ix;
++ EXT_ASSERT(eh->e_num <= eh->e_max);
++ for (k = 0; k < eh->e_num; k++, ix++) {
++ ext_debug(inode, "index: %d -> %d\n",
++ ix->e_block, ix->e_leaf);
++ if (block < ix->e_block)
++ break;
++ path[ppos].p_idx = ix;
++ }
++ path[ppos].p_block = path[ppos].p_idx->e_leaf;
++ path[ppos].p_depth = i;
++ path[ppos].p_hdr = eh;
++ path[ppos].p_ext = NULL;
++
++ bh = sb_bread(inode->i_sb, path[ppos].p_block);
++ if (!bh) {
++ ext3_ext_drop_refs(inode, path);
++ kfree(path);
++ return ERR_PTR(-EIO);
++ }
++ eh = (struct ext3_extent_header *) bh->b_data;
++ ppos++;
++ EXT_ASSERT(ppos <= depth);
++ path[ppos].p_bh = bh;
++ i--;
++ }
++
++ path[ppos].p_depth = i;
++ path[ppos].p_hdr = eh;
++ path[ppos].p_ext = NULL;
++
++ /* find extent */
++ ex = EXT_FIRST_EXTENT(eh);
++ if (eh->e_num)
++ path[ppos].p_ext = ex;
++ EXT_ASSERT(eh->e_num <= eh->e_max);
++ for (k = 0; k < eh->e_num; k++, ex++) {
++ if (block < ex->e_block)
++ break;
++ path[ppos].p_ext = ex;
++ }
++
++ ext3_ext_show_path(inode, path);
++
++ return path;
++}
++
++static void ext3_ext_check_boundary(struct inode *inode,
++ struct ext3_ext_path *curp,
++ void *addr, int len)
++{
++ void *end;
++
++ if (!len)
++ return;
++ if (curp->p_bh)
++ end = (void *) curp->p_hdr + inode->i_sb->s_blocksize;
++ else
++ end = (void *) curp->p_hdr + sizeof(EXT3_I(inode)->i_data);
++ if (((unsigned long) addr) + len > (unsigned long) end) {
++ printk("overflow! 0x%p > 0x%p\n", addr + len, end);
++ BUG();
++ }
++ if ((unsigned long) addr < (unsigned long) curp->p_hdr) {
++ printk("underflow! 0x%p < 0x%p\n", addr, curp->p_hdr);
++ BUG();
++ }
++}
++
++/*
++ * 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 inode *inode,
++ struct ext3_ext_path *curp, int logical,
++ int ptr)
++{
++ struct ext3_extent_idx *ix;
++ int len, err;
++
++ if ((err = ext3_ext_get_access(handle, inode, 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 */
++ len = (len - 1) * sizeof(struct ext3_extent_idx);
++ len = len < 0 ? 0 : len;
++ ext_debug(inode, "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));
++
++ ext3_ext_check_boundary(inode, curp, curp->p_idx + 2, len);
++ 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(inode, "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));
++
++ ext3_ext_check_boundary(inode, curp, curp->p_idx + 1, len);
++ 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++;
++
++ err = ext3_ext_dirty(handle, inode, curp);
++ ext3_std_error(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 inode *inode,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext, int at)
++{
++ struct buffer_head *bh = NULL;
++ int depth = EXT3_I(inode)->i_depth;
++ struct ext3_extent_header *neh;
++ struct ext3_extent_idx *fidx;
++ struct ext3_extent *ex;
++ int i = at, k, m, a;
++ 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 */
++ if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
++ border = path[depth].p_ext[1].e_block;
++ ext_debug(inode, "leaf will be splitted."
++ " next leaf starts at %d\n",
++ (int)border);
++ } else {
++ border = newext->e_block;
++ ext_debug(inode, "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(long) * depth, GFP_NOFS);
++ if (!ablocks)
++ return -ENOMEM;
++ memset(ablocks, 0, sizeof(long) * depth);
++
++ /* allocate all needed blocks */
++ ext_debug(inode, "allocate %d blocks for indexes and leaf\n",
++ depth - at);
++ ablocks[0] = newext->e_start++;
++ newext->e_num--;
++ for (a = 1; a < depth - at; a++) {
++ newblock = ext3_new_block(handle, inode, newext->e_start,
++ 0, 0, &err);
++ if (newblock == 0)
++ goto cleanup;
++ ablocks[a] = newblock;
++ }
++
++ /* initialize new leaf */
++ newblock = ablocks[--a];
++ EXT_ASSERT(newblock);
++ bh = sb_getblk(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 = (struct ext3_extent_header *) bh->b_data;
++ neh->e_num = 0;
++ neh->e_max = ext3_ext_space_block(inode);
++ 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(inode, "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, inode, path)))
++ goto cleanup;
++ path[depth].p_hdr->e_num -= m;
++ if ((err = ext3_ext_dirty(handle, inode, path)))
++ goto cleanup;
++
++ }
++
++ /* create intermediate indexes */
++ k = depth - at - 1;
++ EXT_ASSERT(k >= 0);
++ if (k)
++ ext_debug(inode,
++ "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(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 = (struct ext3_extent_header *) bh->b_data;
++ neh->e_num = 1;
++ neh->e_max = ext3_ext_space_block(inode);
++ fidx = EXT_FIRST_INDEX(neh);
++ fidx->e_block = border;
++ fidx->e_leaf = oldblock;
++
++ ext_debug(inode,
++ "int.index at %d (block %u): %d -> %d\n",
++ i, (unsigned) newblock,
++ (int) border,
++ (int) oldblock);
++ /* copy indexes */
++ m = 0;
++ path[i].p_idx++;
++ EXT_ASSERT(EXT_MAX_INDEX(path[i].p_hdr) ==
++ EXT_LAST_INDEX(path[i].p_hdr));
++ ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx,
++ EXT_MAX_INDEX(path[i].p_hdr));
++ while (path[i].p_idx <=
++ EXT_MAX_INDEX(path[i].p_hdr)) {
++ ext_debug(inode, "%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++;
++ 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,inode,path+i);
++ if (err)
++ goto cleanup;
++ path[i].p_hdr->e_num -= m;
++ err = ext3_ext_dirty(handle, inode, path + i);
++ if (err)
++ goto cleanup;
++ }
++
++ i--;
++ }
++
++ /* insert new index */
++ if (!err)
++ err = ext3_ext_insert_index(handle, inode, 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, 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 inode *inode,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext)
++{
++ struct buffer_head *bh;
++ struct ext3_ext_path *curp = path;
++ struct ext3_extent_header *neh;
++ struct ext3_extent_idx *fidx;
++ int len, err = 0;
++ long newblock;
++
++ /*
++ * use already allocated by the called block for new root block
++ */
++ newblock = newext->e_start++;
++ newext->e_num--;
++
++ bh = sb_getblk(inode->i_sb, newblock);
++ if (!bh) {
++ err = -EIO;
++ ext3_std_error(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 */
++ len = sizeof(struct ext3_extent_header) +
++ sizeof(struct ext3_extent) * curp->p_hdr->e_max;
++ EXT_ASSERT(len >= 0 && len < 4096);
++ memmove(bh->b_data, curp->p_hdr, len);
++
++ /* set size of new block */
++ neh = (struct ext3_extent_header *) bh->b_data;
++ neh->e_max = ext3_ext_space_block(inode);
++ 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, inode, curp)))
++ goto out;
++
++ curp->p_hdr->e_max = ext3_ext_space_inode_idx(inode);
++ curp->p_hdr->e_num = 1;
++ curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
++ curp->p_idx->e_block = EXT_FIRST_EXTENT(path[0].p_hdr)->e_block;
++ curp->p_idx->e_leaf = newblock;
++
++ neh = (struct ext3_extent_header *) EXT3_I(inode)->i_data;
++ fidx = EXT_FIRST_INDEX(neh);
++ ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %d\n",
++ neh->e_num, neh->e_max, fidx->e_block, fidx->e_leaf);
++
++ EXT3_I(inode)->i_depth++;
++ err = ext3_ext_dirty(handle, inode, 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 inode *inode,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext)
++{
++ int depth = EXT3_I(inode)->i_depth;
++ struct ext3_ext_path *curp;
++ int i = depth, err = 0;
++ long newblock = newext->e_start;
++
++ /* 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, inode, path, newext, i);
++ } else {
++ /* tree is full, time to grow in depth */
++ err = ext3_ext_grow_indepth(handle, inode, path, newext);
++ }
++
++ if (!err) {
++ /* refill path */
++ ext3_ext_drop_refs(inode, path);
++ path = ext3_ext_find_extent(inode, newext->e_block, path);
++ if (IS_ERR(path))
++ err = PTR_ERR(path);
++
++ /*
++ * probably we've used some blocks from extent
++ * let's allocate new block for it
++ */
++ if (newext->e_num == 0 && !err) {
++ newext->e_start =
++ ext3_new_block(handle, inode, newblock,
++ 0, 0, &err);
++ newext->e_num = 1;
++ }
++ }
++
++ return err;
++}
++
++/*
++ * returns next allocated block or 0xffffffff
++ * NOTE: it consider block number from index entry as
++ * allocated block. thus, index entries have to be consistent
++ * with leafs
++ */
++static inline unsigned ext3_ext_next_allocated_block(struct inode *inode,
++ 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 inode *inode,
++ 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 inode *inode,
++ struct ext3_ext_path *path)
++{
++ int depth = EXT3_I(inode)->i_depth;
++ struct ext3_extent_header *eh;
++ struct ext3_extent *ex;
++ 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;
++ }
++
++ k = depth - 1;
++ border = path[depth].p_ext->e_block;
++ if ((err = ext3_ext_get_access(handle, inode, path + k)))
++ return err;
++ path[k].p_idx->e_block = border;
++ if ((err = ext3_ext_dirty(handle, inode, path + k)))
++ return err;
++
++ while (k--) {
++ /* change all left-side indexes */
++ if (path[k].p_idx != EXT_FIRST_INDEX(path[k].p_hdr)
++ && k != 0)
++ break;
++ if ((err = ext3_ext_get_access(handle, inode, path + k)))
++ break;
++ path[k].p_idx->e_block = border;
++ if ((err = ext3_ext_dirty(handle, inode, path + k)))
++ break;
++ }
++
++ return err;
++}
++
++/*
++ * 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 inode *inode,
++ struct ext3_ext_path *path,
++ struct ext3_extent *newext)
++{
++ int depth, len;
++ struct ext3_extent_header * eh;
++ struct ext3_extent *ex;
++ struct ext3_extent *nearex; /* nearest extent */
++ struct ext3_ext_path *npath = NULL;
++ int err;
++
++ depth = EXT3_I(inode)->i_depth;
++ if ((ex = path[depth].p_ext)) {
++ /* try to insert block into found extent and return */
++ if (ex->e_block + ex->e_num == newext->e_block &&
++ ex->e_start + ex->e_num == newext->e_start) {
++#ifdef AGRESSIVE_TEST
++ if (ex->e_num >= 2)
++ goto repeat;
++#endif
++ if ((err = ext3_ext_get_access(handle, inode,
++ path + depth)))
++ return err;
++ ext_debug(inode, "append %d block to %d:%d (from %d)\n",
++ newext->e_num, ex->e_block, ex->e_num,
++ ex->e_start);
++ ex->e_num += newext->e_num;
++ err = ext3_ext_dirty(handle, inode, path + depth);
++ return err;
++ }
++ }
++
++repeat:
++ depth = EXT3_I(inode)->i_depth;
++ eh = path[depth].p_hdr;
++ if (eh->e_num == eh->e_max) {
++ /* probably next leaf has space for us? */
++ int next = ext3_ext_next_leaf_block(inode, path);
++ if (next != 0xffffffff) {
++ ext_debug(inode, "next leaf block - %d\n", next);
++ EXT_ASSERT(!npath);
++ npath = ext3_ext_find_extent(inode, 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(inode,
++ "next leaf has free ext(%d)\n",
++ eh->e_num);
++ path = npath;
++ goto repeat;
++ }
++ ext_debug(inode, "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, inode, path, newext);
++ if (err)
++ goto cleanup;
++ goto repeat;
++ }
++
++ nearex = path[depth].p_ext;
++
++ if ((err = ext3_ext_get_access(handle, inode, path + depth)))
++ goto cleanup;
++
++ if (!nearex) {
++ /* there is no extent in this leaf, create first one */
++ ext_debug(inode, "first extent in the leaf: %d:%d:%d\n",
++ newext->e_block, newext->e_start,
++ newext->e_num);
++ eh->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);
++ len = EXT_MAX_EXTENT(eh) - nearex;
++ len = (len - 1) * sizeof(struct ext3_extent);
++ len = len < 0 ? 0 : len;
++ ext_debug(inode, "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);
++ ext3_ext_check_boundary(inode, path + depth, nearex + 2, len);
++ memmove(nearex + 2, nearex + 1, len);
++ path[depth].p_ext = nearex + 1;
++ eh->e_num++;
++ } 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(inode, "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++;
++
++ /* time to correct all indexes above */
++ err = ext3_ext_correct_indexes(handle, inode, path);
++ }
++
++ if (!err) {
++ nearex = path[depth].p_ext;
++ nearex->e_block = newext->e_block;
++ nearex->e_start = newext->e_start;
++ nearex->e_num = newext->e_num;
++ }
++
++ err = ext3_ext_dirty(handle, inode, path + depth);
++
++cleanup:
++ if (npath) {
++ ext3_ext_drop_refs(inode, npath);
++ kfree(npath);
++ }
++
++ return err;
++}
++
++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;
++ int depth = EXT3_I(inode)->i_depth;
++ struct ext3_extent newex;
++ struct ext3_extent *ex;
++ int goal, newblock, err = 0;
++
++ ext_debug(inode, "block %d requested for inode %u, bh_result 0x%p\n",
++ (int) iblock, (unsigned) inode->i_ino, bh_result);
++ bh_result->b_state &= ~(1UL << BH_New);
++
++ down(&EXT3_I(inode)->i_ext_sem);
++
++ /* find extent for this block */
++ path = ext3_ext_find_extent(inode, iblock, NULL);
++ if (IS_ERR(path)) {
++ err = PTR_ERR(path);
++ goto out2;
++ }
++
++ 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(inode, "%d fit into %d:%d -> %d\n",
++ (int) iblock, ex->e_block, ex->e_num,
++ newblock);
++ goto out;
++ }
++ }
++
++ /*
++ * we couldn't try to create block if create flag is zero
++ */
++ if (!create)
++ 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(inode, "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, inode, path, &newex);
++ if (err)
++ goto out2;
++
++ /* previous routine could use block we allocated */
++ newblock = newex.e_start;
++ bh_result->b_state |= (1UL << BH_New);
++
++out:
++ ext3_ext_show_leaf(inode, path);
++ bh_result->b_dev = inode->i_dev;
++ bh_result->b_blocknr = newblock;
++ bh_result->b_state |= (1UL << BH_Mapped);
++out2:
++ ext3_ext_drop_refs(inode, path);
++ kfree(path);
++ up(&EXT3_I(inode)->i_ext_sem);
++
++ return err;
++}
++
++/*
++ * returns 1 if current index have to be freed (even partial)
++ */
++static int ext3_ext_more_to_truncate(struct inode *inode,
++ 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;
++
++ /*
++ * put actual number of indexes to know is this number got
++ * changed at the next iteration
++ */
++ path->p_block = path->p_hdr->e_num;
++
++ return 1;
++}
++
++/*
++ * 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_remove_index(handle_t *handle, struct inode *inode,
++ 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, inode, path)))
++ return err;
++ path->p_hdr->e_num--;
++ if ((err = ext3_ext_dirty(handle, inode, path)))
++ return err;
++ bh = sb_get_hash_table(inode->i_sb, path->p_idx->e_leaf);
++ ext3_forget(handle, 0, inode, bh, path->p_idx->e_leaf);
++ ext3_free_blocks(handle, inode, path->p_idx->e_leaf, 1);
++
++ ext_debug(inode, "index is empty, remove it, free block %d\n",
++ path->p_idx->e_leaf);
++ return err;
++}
++
++/*
++ * returns 1 if current extent needs to be freed (even partial)
++ * instead, returns 0
++ */
++int ext3_ext_more_leaves_to_truncate(struct inode *inode,
++ struct ext3_ext_path *path)
++{
++ unsigned blocksize = inode->i_sb->s_blocksize;
++ struct ext3_extent *ex = path->p_ext;
++ int last_block;
++
++ EXT_ASSERT(ex);
++
++ /* is there leave in the current leaf? */
++ if (ex < EXT_FIRST_EXTENT(path->p_hdr))
++ return 0;
++
++ last_block = (inode->i_size + blocksize-1)
++ >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
++
++ if (last_block >= ex->e_block + ex->e_num)
++ return 0;
++
++ /* seems it extent have to be freed */
++ return 1;
++}
++
++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;
++}
++
++/*
++ * this routine calculate max number of blocks to be modified
++ * while freeing extent and is intended to be used in truncate path
++ */
++static int ext3_ext_calc_credits(struct inode *inode,
++ struct ext3_ext_path *path,
++ int num)
++{
++ int depth = EXT3_I(inode)->i_depth;
++ int needed;
++
++ /*
++ * extent couldn't cross group, so we will modify
++ * single bitmap block and single group descriptor
++ */
++ needed = 2;
++
++ /*
++ * if this is last extent in a leaf, then we have to
++ * free leaf block and remove pointer from index above.
++ * that pointer could be last in index block, so we'll
++ * have to remove it too. this way we could modify/free
++ * the whole path + root index (inode stored) will be
++ * modified
++ */
++ if (!path || (num == path->p_ext->e_num &&
++ path->p_ext == EXT_FIRST_EXTENT(path->p_hdr)))
++ needed += (depth * EXT3_ALLOC_NEEDED) + 1;
++
++ /*
++ * it seems current calculation has bug
++ * this is workaround -bzzz
++ */
++ needed += 10;
++
++ return needed;
++}
++
++/*
++ * core of the truncate procedure:
++ * - calculated what part of each extent in the requested leaf
++ * need to be freed
++ * - frees and forgets these blocks
++ *
++ * TODO: we could optimize and free several extents during
++ * single journal_restart()-journal_restart() cycle
++ */
++static int ext3_ext_truncate_leaf(handle_t *handle,
++ struct inode *inode,
++ struct ext3_ext_path *path,
++ int depth)
++{
++ unsigned blocksize = inode->i_sb->s_blocksize;
++ int last_block;
++ int i, err = 0, sf, num;
++
++ ext_debug(inode, "level %d - leaf\n", depth);
++ if (!path->p_hdr)
++ path->p_hdr =
++ (struct ext3_extent_header *) path->p_bh->b_data;
++
++ EXT_ASSERT(path->p_hdr->e_num <= path->p_hdr->e_max);
++
++ last_block = (inode->i_size + blocksize-1)
++ >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
++ path->p_ext = EXT_LAST_EXTENT(path->p_hdr);
++ while (ext3_ext_more_leaves_to_truncate(inode, path)) {
++
++ /* what part of extent have to be freed? */
++ sf = last_block > path->p_ext->e_block ?
++ last_block : path->p_ext->e_block;
++
++ /* number of blocks from extent to be freed */
++ num = path->p_ext->e_block + path->p_ext->e_num - sf;
++
++ /* calc physical first physical block to be freed */
++ sf = path->p_ext->e_start + (sf - path->p_ext->e_block);
++
++ i = ext3_ext_calc_credits(inode, path, num);
++ handle = ext3_ext_journal_restart(handle, i);
++ if (IS_ERR(handle))
++ return PTR_ERR(handle);
++
++ ext_debug(inode, "free extent %d:%d:%d -> free %d:%d\n",
++ path->p_ext->e_block, path->p_ext->e_start,
++ path->p_ext->e_num, sf, num);
++ for (i = 0; i < num; i++) {
++ struct buffer_head *bh =
++ sb_get_hash_table(inode->i_sb, sf + i);
++ ext3_forget(handle, 0, inode, bh, sf + i);
++ }
++ ext3_free_blocks(handle, inode, sf, num);
++
++ /* collect extents usage stats */
++ spin_lock(&EXT3_SB(inode->i_sb)->s_ext_lock);
++ EXT3_SB(inode->i_sb)->s_ext_extents++;
++ EXT3_SB(inode->i_sb)->s_ext_blocks += num;
++ spin_unlock(&EXT3_SB(inode->i_sb)->s_ext_lock);
++
++ /* reduce extent */
++ if ((err = ext3_ext_get_access(handle, inode, path)))
++ return err;
++ path->p_ext->e_num -= num;
++ if (path->p_ext->e_num == 0)
++ path->p_hdr->e_num--;
++ if ((err = ext3_ext_dirty(handle, inode, path)))
++ return err;
++
++ path->p_ext--;
++ }
++
++ /* if this leaf is free, then we should
++ * remove it from index block above */
++ if (path->p_hdr->e_num == 0 && depth > 0)
++ err = ext3_ext_remove_index(handle, inode, path);
++
++ return err;
++}
++
++static void ext3_ext_collect_stats(struct inode *inode)
++{
++ int depth;
++
++ /* skip inodes with old good bitmap */
++ if (!(EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL))
++ return;
++
++ /* collect on full truncate only */
++ if (inode->i_size)
++ return;
++
++ depth = EXT3_I(inode)->i_depth;
++ if (depth < EXT3_SB(inode->i_sb)->s_ext_mindepth)
++ EXT3_SB(inode->i_sb)->s_ext_mindepth = depth;
++ if (depth > EXT3_SB(inode->i_sb)->s_ext_maxdepth)
++ EXT3_SB(inode->i_sb)->s_ext_maxdepth = depth;
++ EXT3_SB(inode->i_sb)->s_ext_sum += depth;
++ EXT3_SB(inode->i_sb)->s_ext_count++;
++
++}
++
++void ext3_ext_truncate(struct inode * inode)
++{
++ struct address_space *mapping = inode->i_mapping;
++ struct ext3_ext_path *path;
++ struct page * page;
++ handle_t *handle;
++ int i, depth, err = 0;
++
++ ext3_ext_collect_stats(inode);
++
++ /*
++ * We have to lock the EOF page here, because lock_page() nests
++ * outside journal_start().
++ */
++ if ((inode->i_size & (inode->i_sb->s_blocksize - 1)) == 0) {
++ /* Block boundary? Nothing to do */
++ page = NULL;
++ } else {
++ page = grab_cache_page(mapping,
++ inode->i_size >> PAGE_CACHE_SHIFT);
++ if (!page)
++ return;
++ }
++
++ /*
++ * probably first extent we're gonna free will be last in block
++ */
++ i = ext3_ext_calc_credits(inode, NULL, 0);
++ handle = ext3_journal_start(inode, i);
++ 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, mapping, inode->i_size, page,
++ inode->i_sb->s_blocksize);
++
++ down(&EXT3_I(inode)->i_ext_sem);
++
++ /*
++ * 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);
++
++ /*
++ * we start scanning from right side freeing all the blocks
++ * after i_size and walking into the deep
++ */
++ i = 0;
++ depth = EXT3_I(inode)->i_depth;
++ path = kmalloc(sizeof(struct ext3_ext_path) * (depth + 1), GFP_KERNEL);
++ if (IS_ERR(path)) {
++ ext3_error(inode->i_sb, "ext3_ext_truncate",
++ "Can't allocate path array");
++ goto out_stop;
++ }
++ memset(path, 0, sizeof(struct ext3_ext_path) * (depth + 1));
++
++ path[i].p_hdr = (struct ext3_extent_header *) EXT3_I(inode)->i_data;
++ while (i >= 0 && err == 0) {
++ if (i == depth) {
++ /* this is leaf block */
++ err = ext3_ext_truncate_leaf(handle, inode,
++ path + i, i);
++ /* 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) {
++ path[i].p_hdr =
++ (struct ext3_extent_header *) path[i].p_bh->b_data;
++ ext_debug(inode, "initialize header\n");
++ }
++
++ EXT_ASSERT(path[i].p_hdr->e_num <= path[i].p_hdr->e_max);
++
++ if (!path[i].p_idx) {
++ /* this level hasn't touched yet */
++ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
++ path[i].p_block = path[i].p_hdr->e_num + 1;
++ ext_debug(inode, "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(inode, "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_truncate(inode, path + i)) {
++ /* go to the next level */
++ ext_debug(inode, "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(inode->i_sb,
++ path[i].p_idx->e_leaf);
++ if (!path[i+1].p_bh) {
++ /* should we reset i_size? */
++ err = -EIO;
++ break;
++ }
++ 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_remove_index(handle, inode,
++ path + i);
++ }
++ /* root level have p_bh == NULL, brelse() eats this */
++ brelse(path[i].p_bh);
++ i--;
++ ext_debug(inode, "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 i_depth
++ */
++ EXT3_I(inode)->i_depth = 0;
++ path->p_hdr->e_max = 0;
++ ext3_mark_inode_dirty(handle, inode);
++ }
++
++ kfree(path);
++
++ /* 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)->i_ext_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_inode_info *ei = EXT3_I(inode);
++ int depth = ei->i_depth + 1;
++ int needed;
++
++ /*
++ * 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
++ */
++
++ /*
++ * 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;
++
++ /* 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;
++}
++
++/*
++ * 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\n");
++ spin_lock_init(&EXT3_SB(sb)->s_ext_lock);
++}
++
++/*
++ * called at umount time
++ */
++void ext3_ext_release(struct super_block *sb)
++{
++ struct ext3_sb_info *sbi = EXT3_SB(sb);
++
++ /* show collected stats */
++ if (sbi->s_ext_count && sbi->s_ext_extents)
++ printk("EXT3-fs: min depth - %d, max depth - %d, "
++ "ave. depth - %d, ave. blocks/extent - %d\n",
++ sbi->s_ext_mindepth,
++ sbi->s_ext_maxdepth,
++ sbi->s_ext_sum / sbi->s_ext_count,
++ sbi->s_ext_blocks / sbi->s_ext_extents);
++}
++
+--- linux-2.4.18-chaos/fs/ext3/ialloc.c~ext3-extents-2.4.18-chaos-pdirops 2003-09-17 00:20:20.000000000 +0400
++++ linux-2.4.18-chaos-alexey/fs/ext3/ialloc.c 2003-09-17 00:20:21.000000000 +0400
+@@ -573,6 +573,10 @@ repeat:
+ ei->i_prealloc_count = 0;
+ #endif
+ ei->i_block_group = i;
++ if (test_opt(sb, EXTENTS))
++ EXT3_I(inode)->i_flags |= EXT3_EXTENTS_FL;
++ ei->i_depth = 0;
++ sema_init(&ei->i_ext_sem, 1);
+
+ if (ei->i_flags & EXT3_SYNC_FL)
+ inode->i_flags |= S_SYNC;
+--- linux-2.4.18-chaos/fs/ext3/inode.c~ext3-extents-2.4.18-chaos-pdirops 2003-09-17 00:20:20.000000000 +0400
++++ linux-2.4.18-chaos-alexey/fs/ext3/inode.c 2003-09-17 00:20:21.000000000 +0400
+@@ -842,6 +842,15 @@ changed:
+ goto reread;
+ }
+
++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, 1);
++ return ext3_get_block_handle(handle, inode, block, bh, create, 1);
++}
++
+ /*
+ * The BKL is not held on entry here.
+ */
+@@ -855,7 +864,7 @@ static int ext3_get_block(struct inode *
+ handle = ext3_journal_current_handle();
+ J_ASSERT(handle != 0);
+ }
+- ret = ext3_get_block_handle(handle, inode, iblock,
++ ret = ext3_get_block_wrap(handle, inode, iblock,
+ bh_result, create, 1);
+ return ret;
+ }
+@@ -882,7 +891,7 @@ ext3_direct_io_get_block(struct inode *i
+ }
+ }
+ if (ret == 0)
+- ret = ext3_get_block_handle(handle, inode, iblock,
++ ret = ext3_get_block_wrap(handle, inode, iblock,
+ bh_result, create, 0);
+ if (ret == 0)
+ bh_result->b_size = (1 << inode->i_blkbits);
+@@ -904,7 +913,7 @@ 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);
+@@ -1520,7 +1529,7 @@ ext3_block_truncate_page_prepare(struct
+ * 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,
+ struct page *page, unsigned blocksize)
+ {
+@@ -1998,6 +2007,9 @@ void ext3_truncate(struct inode * inode)
+
+ ext3_discard_prealloc(inode);
+
++ if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
++ return ext3_ext_truncate(inode);
++
+ blocksize = inode->i_sb->s_blocksize;
+ last_block = (inode->i_size + blocksize-1)
+ >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
+@@ -2436,6 +2448,8 @@ void ext3_read_inode(struct inode * inod
+ ei->i_prealloc_count = 0;
+ #endif
+ ei->i_block_group = iloc.block_group;
++ ei->i_depth = raw_inode->osd2.linux2.l_i_depth;
++ sema_init(&ei->i_ext_sem, 1);
+
+ /*
+ * NOTE! The in-memory inode i_data array is in little-endian order
+@@ -2559,6 +2573,7 @@ static int ext3_do_update_inode(handle_t
+ raw_inode->i_fsize = 0;
+ }
+ #endif
++ raw_inode->osd2.linux2.l_i_depth = ei->i_depth;
+ raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
+ if (!S_ISREG(inode->i_mode)) {
+ raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
+@@ -2762,6 +2777,9 @@ int ext3_writepage_trans_blocks(struct i
+ 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
+@@ -3085,7 +3103,7 @@ int ext3_prep_san_write(struct inode *in
+
+ /* 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, 1);
+ if (ret)
+ break;
+@@ -3146,7 +3164,7 @@ int ext3_map_inode_page(struct inode *in
+ if (blocks[i] != 0)
+ continue;
+
+- rc = ext3_get_block_handle(handle, inode, iblock, &dummy, 1, 1);
++ rc = ext3_get_block_wrap(handle, inode, iblock, &dummy, 1, 1);
+ if (rc) {
+ printk(KERN_INFO "ext3_map_inode_page: error reading "
+ "block %ld\n", iblock);
+--- linux-2.4.18-chaos/fs/ext3/Makefile~ext3-extents-2.4.18-chaos-pdirops 2003-09-16 23:47:28.000000000 +0400
++++ linux-2.4.18-chaos-alexey/fs/ext3/Makefile 2003-09-17 00:20:21.000000000 +0400
+@@ -12,7 +12,8 @@ O_TARGET := ext3.o
+ export-objs := ext3-exports.o
+
+ obj-y := balloc.o iopen.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
+- ioctl.o namei.o super.o symlink.o xattr.o hash.o ext3-exports.o
++ ioctl.o namei.o super.o symlink.o xattr.o hash.o ext3-exports.o \
++ extents.o
+ obj-m := $(O_TARGET)
+
+ include $(TOPDIR)/Rules.make
+--- linux-2.4.18-chaos/fs/ext3/super.c~ext3-extents-2.4.18-chaos-pdirops 2003-09-17 00:20:20.000000000 +0400
++++ linux-2.4.18-chaos-alexey/fs/ext3/super.c 2003-09-17 00:20:21.000000000 +0400
+@@ -619,6 +619,7 @@ void ext3_put_super (struct super_block
+ kdev_t j_dev = sbi->s_journal->j_dev;
+ int i;
+
++ ext3_ext_release(sb);
+ ext3_stop_delete_thread(sbi);
+ ext3_xattr_put_super(sb);
+ journal_destroy(sbi->s_journal);
+@@ -741,6 +742,12 @@ static int parse_options (char * options
+ else
+ #endif
+
++ if (!strcmp (this_char, "extents"))
++ set_opt (sbi->s_mount_opt, EXTENTS);
++ else
++ if (!strcmp (this_char, "extdebug"))
++ set_opt (sbi->s_mount_opt, EXTDEBUG);
++ else
+ if (!strcmp (this_char, "bsddf"))
+ clear_opt (*mount_options, MINIX_DF);
+ else if (!strcmp (this_char, "nouid32")) {
+@@ -1471,6 +1478,7 @@ struct super_block * ext3_read_super (st
+ test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ? "journal":
+ test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
+ "writeback");
++ ext3_ext_init(sb);
+
+ if (test_opt(sb, PDIROPS)) {
+ printk (KERN_INFO "EXT3-fs: mounted filesystem with parallel dirops\n");
+--- linux-2.4.18-chaos/include/linux/ext3_fs.h~ext3-extents-2.4.18-chaos-pdirops 2003-09-17 00:20:20.000000000 +0400
++++ linux-2.4.18-chaos-alexey/include/linux/ext3_fs.h 2003-09-17 00:20:21.000000000 +0400
+@@ -188,6 +188,7 @@ struct ext3_group_desc
+ #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 */
+@@ -248,7 +249,7 @@ struct ext3_inode {
+ struct {
+ __u8 l_i_frag; /* Fragment number */
+ __u8 l_i_fsize; /* Fragment size */
+- __u16 i_pad1;
++ __u16 l_i_depth;
+ __u16 l_i_uid_high; /* these 2 fields */
+ __u16 l_i_gid_high; /* were reserved2[0] */
+ __u32 l_i_reserved2;
+@@ -330,6 +331,8 @@ struct ext3_inode {
+ #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 0x40000 /* Extents support */
++#define EXT3_MOUNT_EXTDEBUG 0x80000 /* Extents debug */
+
+ /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
+ #ifndef _LINUX_EXT2_FS_H
+@@ -721,6 +724,12 @@ extern void ext3_discard_prealloc (struc
+ extern void ext3_dirty_inode(struct inode *);
+ extern int ext3_change_inode_journal_flag(struct inode *, int);
+ extern void ext3_truncate (struct inode *);
++extern int ext3_block_truncate_page(handle_t *handle,
++ struct address_space *mapping, loff_t from,
++ struct page *page, unsigned blocksize);
++extern int ext3_forget(handle_t *handle, int is_metadata,
++ struct inode *inode, struct buffer_head *bh,
++ int blocknr);
+ #ifdef EXT3_DELETE_THREAD
+ extern void ext3_truncate_thread(struct inode *inode);
+ #endif
+@@ -782,6 +791,13 @@ extern struct inode_operations ext3_dir_
+ /* symlink.c */
+ 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 *);
++extern void ext3_ext_init(struct super_block *);
++extern void ext3_ext_release(struct super_block *);
+
+ #endif /* __KERNEL__ */
+
+--- linux-2.4.18-chaos/include/linux/ext3_fs_i.h~ext3-extents-2.4.18-chaos-pdirops 2003-09-17 00:20:20.000000000 +0400
++++ linux-2.4.18-chaos-alexey/include/linux/ext3_fs_i.h 2003-09-17 00:20:21.000000000 +0400
+@@ -79,6 +79,10 @@ struct ext3_inode_info {
+ struct dynlock i_htree_lock;
+ struct semaphore i_append_sem;
+ struct semaphore i_rename_sem;
++
++ /* extents-related data */
++ struct semaphore i_ext_sem;
++ __u16 i_depth;
+ };
+
+ #endif /* _LINUX_EXT3_FS_I */
+--- linux-2.4.18-chaos/include/linux/ext3_fs_sb.h~ext3-extents-2.4.18-chaos-pdirops 2003-09-16 23:45:39.000000000 +0400
++++ linux-2.4.18-chaos-alexey/include/linux/ext3_fs_sb.h 2003-09-17 00:20:21.000000000 +0400
+@@ -86,6 +86,16 @@ struct ext3_sb_info {
+ wait_queue_head_t s_delete_thread_queue;
+ wait_queue_head_t s_delete_waiter_queue;
+ #endif
++
++ /* extents */
++ int s_ext_debug;
++ int s_ext_mindepth;
++ int s_ext_maxdepth;
++ int s_ext_sum;
++ int s_ext_count;
++ spinlock_t s_ext_lock;
++ int s_ext_extents;
++ int s_ext_blocks;
+ };
+
+ #endif /* _LINUX_EXT3_FS_SB */
+
+_
git://git.whamcloud.com / fs / lustre-release.git / commitdiff