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ext2fs: don't ignore return value in ext2fs_count_blocks
[tools/e2fsprogs.git] / lib / ext2fs / extent.c
index 9881c77..9e61103 100644 (file)
@@ -4,11 +4,12 @@
  * Copyright (C) 2007 Theodore Ts'o.
  *
  * %Begin-Header%
- * This file may be redistributed under the terms of the GNU Public
- * License.
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
  * %End-Header%
  */
 
+#include "config.h"
 #include <stdio.h>
 #include <string.h>
 #if HAVE_UNISTD_H
@@ -27,7 +28,8 @@
 #include "ext2_fs.h"
 #include "ext2fsP.h"
 #include "e2image.h"
-#include "ss/ss.h"
+
+#undef DEBUG
 
 /*
  * Definitions to be dropped in lib/ext2fs/ext2fs.h
@@ -54,9 +56,11 @@ struct ext2_extent_handle {
        ext2_filsys             fs;
        ext2_ino_t              ino;
        struct ext2_inode       *inode;
+       struct ext2_inode       inodebuf;
        int                     type;
        int                     level;
        int                     max_depth;
+       int                     max_paths;
        struct extent_path      *path;
 };
 
@@ -74,28 +78,38 @@ struct ext2_extent_path {
 static void dbg_show_header(struct ext3_extent_header *eh)
 {
        printf("header: magic=%x entries=%u max=%u depth=%u generation=%u\n",
-              eh->eh_magic, eh->eh_entries, eh->eh_max, eh->eh_depth,
-              eh->eh_generation);
+                       ext2fs_le16_to_cpu(eh->eh_magic),
+                       ext2fs_le16_to_cpu(eh->eh_entries),
+                       ext2fs_le16_to_cpu(eh->eh_max),
+                       ext2fs_le16_to_cpu(eh->eh_depth),
+                       ext2fs_le32_to_cpu(eh->eh_generation));
 }
 
 static void dbg_show_index(struct ext3_extent_idx *ix)
 {
        printf("index: block=%u leaf=%u leaf_hi=%u unused=%u\n",
-              ix->ei_block, ix->ei_leaf, ix->ei_leaf_hi, ix->ei_unused);
+                       ext2fs_le32_to_cpu(ix->ei_block),
+                       ext2fs_le32_to_cpu(ix->ei_leaf),
+                       ext2fs_le16_to_cpu(ix->ei_leaf_hi),
+                       ext2fs_le16_to_cpu(ix->ei_unused));
 }
 
 static void dbg_show_extent(struct ext3_extent *ex)
 {
        printf("extent: block=%u-%u len=%u start=%u start_hi=%u\n",
-              ex->ee_block, ex->ee_block + ex->ee_len - 1,
-              ex->ee_len, ex->ee_start, ex->ee_start_hi);
+                       ext2fs_le32_to_cpu(ex->ee_block),
+                       ext2fs_le32_to_cpu(ex->ee_block) +
+                       ext2fs_le16_to_cpu(ex->ee_len) - 1,
+                       ext2fs_le16_to_cpu(ex->ee_len),
+                       ext2fs_le32_to_cpu(ex->ee_start),
+                       ext2fs_le16_to_cpu(ex->ee_start_hi));
 }
 
 static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
 {
        if (desc)
                printf("%s: ", desc);
-       printf("extent: lblk %llu--%llu, len %lu, pblk %llu, flags: ",
+       printf("extent: lblk %llu--%llu, len %u, pblk %llu, flags: ",
               extent->e_lblk, extent->e_lblk + extent->e_len - 1,
               extent->e_len, extent->e_pblk);
        if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
@@ -110,13 +124,39 @@ static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
 
 }
 
-#define dbg_printf(fmt, args...) printf(fmt, ## args)
+static void dump_path(const char *tag, struct ext2_extent_handle *handle,
+                     struct extent_path *path)
+{
+       struct extent_path *ppp = path;
+       printf("%s: level=%d\n", tag, handle->level);
+
+       do {
+               printf("%s: path=%ld buf=%p entries=%d max_entries=%d left=%d "
+                      "visit_num=%d flags=0x%x end_blk=%llu curr=%p(%ld)\n",
+                      tag, (ppp - handle->path), ppp->buf, ppp->entries,
+                      ppp->max_entries, ppp->left, ppp->visit_num, ppp->flags,
+                      ppp->end_blk, ppp->curr, ppp->curr - (void *)ppp->buf);
+               printf("  ");
+               dbg_show_header((struct ext3_extent_header *)ppp->buf);
+               if (ppp->curr) {
+                       printf("  ");
+                       dbg_show_index(ppp->curr);
+                       printf("  ");
+                       dbg_show_extent(ppp->curr);
+               }
+               ppp--;
+       } while (ppp >= handle->path);
+       fflush(stdout);
+
+       return;
+}
+
 #else
 #define dbg_show_header(eh) do { } while (0)
 #define dbg_show_index(ix) do { } while (0)
 #define dbg_show_extent(ex) do { } while (0)
 #define dbg_print_extent(desc, ex) do { } while (0)
-#define dbg_printf(fmt, args...) do { } while (0)
+#define dump_path(tag, handle, path) do { } while (0)
 #endif
 
 /*
@@ -140,7 +180,7 @@ errcode_t ext2fs_extent_header_verify(void *ptr, int size)
        eh_max = (size - sizeof(*eh)) / entry_size;
        /* Allow two extent-sized items at the end of the block, for
         * ext4_extent_tail with checksum in the future. */
-       if ((ext2fs_le16_to_cpu(eh->eh_max) > eh_max) || 
+       if ((ext2fs_le16_to_cpu(eh->eh_max) > eh_max) ||
            (ext2fs_le16_to_cpu(eh->eh_max) < (eh_max - 2)))
                return EXT2_ET_EXTENT_HEADER_BAD;
 
@@ -151,18 +191,15 @@ errcode_t ext2fs_extent_header_verify(void *ptr, int size)
 /*
  * Begin functions to handle an inode's extent information
  */
-
-extern void ext2fs_extent_free(ext2_extent_handle_t handle)
+void ext2fs_extent_free(ext2_extent_handle_t handle)
 {
        int                     i;
 
        if (!handle)
                return;
 
-       if (handle->inode)
-               ext2fs_free_mem(&handle->inode);
        if (handle->path) {
-               for (i=1; i < handle->max_depth; i++) {
+               for (i = 1; i < handle->max_paths; i++) {
                        if (handle->path[i].buf)
                                ext2fs_free_mem(&handle->path[i].buf);
                }
@@ -171,53 +208,75 @@ extern void ext2fs_extent_free(ext2_extent_handle_t handle)
        ext2fs_free_mem(&handle);
 }
 
-extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
+errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
+                                   ext2_extent_handle_t *ret_handle)
+{
+       return ext2fs_extent_open2(fs, ino, NULL, ret_handle);
+}
+
+errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino,
+                                   struct ext2_inode *inode,
                                    ext2_extent_handle_t *ret_handle)
 {
        struct ext2_extent_handle       *handle;
        errcode_t                       retval;
-       int                             isize = EXT2_INODE_SIZE(fs->super);
+       int                             i;
        struct ext3_extent_header       *eh;
-       struct ext3_extent_idx          *ix;
 
        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 
-       if ((ino == 0) || (ino > fs->super->s_inodes_count))
-               return EXT2_ET_BAD_INODE_NUM;
+       if (!inode)
+               if ((ino == 0) || (ino > fs->super->s_inodes_count))
+                       return EXT2_ET_BAD_INODE_NUM;
 
        retval = ext2fs_get_mem(sizeof(struct ext2_extent_handle), &handle);
        if (retval)
                return retval;
        memset(handle, 0, sizeof(struct ext2_extent_handle));
 
-       retval = ext2fs_get_mem(isize, &handle->inode);
-       if (retval)
-               goto errout;
-
        handle->ino = ino;
        handle->fs = fs;
 
-       retval = ext2fs_read_inode_full(fs, ino, handle->inode, isize);
-       if (retval)
-               goto errout;
+       if (inode) {
+               handle->inode = inode;
+       } else {
+               handle->inode = &handle->inodebuf;
+               retval = ext2fs_read_inode(fs, ino, handle->inode);
+               if (retval)
+                       goto errout;
+       }
+
+       eh = (struct ext3_extent_header *) &handle->inode->i_block[0];
 
-       if (!(handle->inode->i_flags & EXT4_EXTENTS_FL))
-               return EXT2_ET_INODE_NOT_EXTENT;
+       for (i=0; i < EXT2_N_BLOCKS; i++)
+               if (handle->inode->i_block[i])
+                       break;
+       if (i >= EXT2_N_BLOCKS) {
+               eh->eh_magic = ext2fs_cpu_to_le16(EXT3_EXT_MAGIC);
+               eh->eh_depth = 0;
+               eh->eh_entries = 0;
+               i = (sizeof(handle->inode->i_block) - sizeof(*eh)) /
+                       sizeof(struct ext3_extent);
+               eh->eh_max = ext2fs_cpu_to_le16(i);
+               handle->inode->i_flags |= EXT4_EXTENTS_FL;
+       }
 
-       eh = (struct ext3_extent_header *) &handle->inode->i_block;
+       if (!(handle->inode->i_flags & EXT4_EXTENTS_FL)) {
+               retval = EXT2_ET_INODE_NOT_EXTENT;
+               goto errout;
+       }
 
        retval = ext2fs_extent_header_verify(eh, sizeof(handle->inode->i_block));
        if (retval)
-               return (retval);
+               goto errout;
 
        handle->max_depth = ext2fs_le16_to_cpu(eh->eh_depth);
        handle->type = ext2fs_le16_to_cpu(eh->eh_magic);
 
-       retval = ext2fs_get_mem(((handle->max_depth+1) *
-                                sizeof(struct extent_path)),
-                               &handle->path);
-       memset(handle->path, 0,
-              (handle->max_depth+1) * sizeof(struct extent_path));
+       handle->max_paths = handle->max_depth + 1;
+       retval = ext2fs_get_memzero(handle->max_paths *
+                                   sizeof(struct extent_path),
+                                   &handle->path);
        handle->path[0].buf = (char *) handle->inode->i_block;
 
        handle->path[0].left = handle->path[0].entries =
@@ -225,9 +284,8 @@ extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
        handle->path[0].max_entries = ext2fs_le16_to_cpu(eh->eh_max);
        handle->path[0].curr = 0;
        handle->path[0].end_blk =
-               ((((__u64) handle->inode->i_size_high << 32) +
-                 handle->inode->i_size + (fs->blocksize - 1))
-                >> EXT2_BLOCK_SIZE_BITS(fs->super));
+               (EXT2_I_SIZE(handle->inode) + fs->blocksize - 1) >>
+                EXT2_BLOCK_SIZE_BITS(fs->super);
        handle->path[0].visit_num = 1;
        handle->level = 0;
        handle->magic = EXT2_ET_MAGIC_EXTENT_HANDLE;
@@ -252,9 +310,10 @@ errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
        struct ext3_extent_idx          *ix = 0;
        struct ext3_extent              *ex;
        errcode_t                       retval;
-       blk_t                           blk;
+       blk64_t                         blk;
        blk64_t                         end_blk;
        int                             orig_op, op;
+       int                             failed_csum = 0;
 
        EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 
@@ -288,9 +347,11 @@ retry:
                                return EXT2_ET_EXTENT_NO_NEXT;
                }
                if (op != EXT2_EXTENT_NEXT_SIB) {
-                       dbg_printf("<<<< OP = %s\n",
+#ifdef DEBUG_GET_EXTENT
+                       printf("<<<< OP = %s\n",
                               (op == EXT2_EXTENT_DOWN) ? "down" :
                               ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
+#endif
                }
        }
 
@@ -317,9 +378,11 @@ retry:
                                return EXT2_ET_EXTENT_NO_PREV;
                }
                if (op != EXT2_EXTENT_PREV_SIB) {
-                       dbg_printf("<<<< OP = %s\n",
+#ifdef DEBUG_GET_EXTENT
+                       printf("<<<< OP = %s\n",
                               (op == EXT2_EXTENT_DOWN_AND_LAST) ? "down/last" :
                               ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
+#endif
                }
        }
 
@@ -329,8 +392,10 @@ retry:
                        op = EXT2_EXTENT_DOWN;
                else
                        op = EXT2_EXTENT_LAST_SIB;
-               dbg_printf("<<<< OP = %s\n",
+#ifdef DEBUG_GET_EXTENT
+               printf("<<<< OP = %s\n",
                           (op == EXT2_EXTENT_DOWN) ? "down" : "last_sib");
+#endif
        }
 
        switch (op) {
@@ -340,9 +405,11 @@ retry:
        case EXT2_EXTENT_ROOT:
                handle->level = 0;
                path = handle->path + handle->level;
+               /* fallthrough */
        case EXT2_EXTENT_FIRST_SIB:
                path->left = path->entries;
                path->curr = 0;
+               /* fallthrough */
        case EXT2_EXTENT_NEXT_SIB:
                if (path->left <= 0)
                        return EXT2_ET_EXTENT_NO_NEXT;
@@ -404,7 +471,7 @@ retry:
                    (handle->fs->io != handle->fs->image_io))
                        memset(newpath->buf, 0, handle->fs->blocksize);
                else {
-                       retval = io_channel_read_blk(handle->fs->io,
+                       retval = io_channel_read_blk64(handle->fs->io,
                                                     blk, 1, newpath->buf);
                        if (retval)
                                return retval;
@@ -414,8 +481,15 @@ retry:
                eh = (struct ext3_extent_header *) newpath->buf;
 
                retval = ext2fs_extent_header_verify(eh, handle->fs->blocksize);
-               if (retval)
+               if (retval) {
+                       handle->level--;
                        return retval;
+               }
+
+               if (!(handle->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
+                   !ext2fs_extent_block_csum_verify(handle->fs, handle->ino,
+                                                    eh))
+                       failed_csum = 1;
 
                newpath->left = newpath->entries =
                        ext2fs_le16_to_cpu(eh->eh_entries);
@@ -440,11 +514,11 @@ retry:
                        if (handle->level < handle->max_depth)
                                path->visit_num = 1;
                }
-
-               dbg_printf("Down to level %d/%d, end_blk=%llu\n",
+#ifdef DEBUG_GET_EXTENT
+               printf("Down to level %d/%d, end_blk=%llu\n",
                           handle->level, handle->max_depth,
                           path->end_blk);
-
+#endif
                break;
        default:
                return EXT2_ET_OP_NOT_SUPPORTED;
@@ -454,6 +528,9 @@ retry:
                return EXT2_ET_NO_CURRENT_NODE;
 
        extent->e_flags = 0;
+#ifdef DEBUG_GET_EXTENT
+       printf("(Left %d)\n", path->left);
+#endif
 
        if (handle->level == handle->max_depth) {
                ex = (struct ext3_extent *) ix;
@@ -462,10 +539,10 @@ retry:
                        ((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
                extent->e_lblk = ext2fs_le32_to_cpu(ex->ee_block);
                extent->e_len = ext2fs_le16_to_cpu(ex->ee_len);
-               extent->e_flags = EXT2_EXTENT_FLAGS_LEAF;
+               extent->e_flags |= EXT2_EXTENT_FLAGS_LEAF;
                if (extent->e_len > EXT_INIT_MAX_LEN) {
                        extent->e_len -= EXT_INIT_MAX_LEN;
-                       extent->e_flags = EXT2_EXTENT_FLAGS_UNINIT;
+                       extent->e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
                }
        } else {
                extent->e_pblk = ext2fs_le32_to_cpu(ix->ei_leaf) +
@@ -492,30 +569,42 @@ retry:
             (path->left != 0)))
                goto retry;
 
+       if (failed_csum)
+               return EXT2_ET_EXTENT_CSUM_INVALID;
+
        return 0;
 }
 
 static errcode_t update_path(ext2_extent_handle_t handle)
 {
-       struct extent_path              *path;
        blk64_t                         blk;
        errcode_t                       retval;
        struct ext3_extent_idx          *ix;
+       struct ext3_extent_header       *eh;
 
        if (handle->level == 0) {
-               retval = ext2fs_write_inode_full(handle->fs, handle->ino,
-                          handle->inode, EXT2_INODE_SIZE(handle->fs->super));
+               retval = ext2fs_write_inode(handle->fs, handle->ino,
+                                           handle->inode);
        } else {
                ix = handle->path[handle->level - 1].curr;
                blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
                        ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 
-               retval = io_channel_write_blk(handle->fs->io,
+               /* then update the checksum */
+               eh = (struct ext3_extent_header *)
+                               handle->path[handle->level].buf;
+               retval = ext2fs_extent_block_csum_set(handle->fs, handle->ino,
+                                                     eh);
+               if (retval)
+                       return retval;
+
+               retval = io_channel_write_blk64(handle->fs->io,
                                      blk, 1, handle->path[handle->level].buf);
        }
        return retval;
 }
 
+#if 0
 errcode_t ext2fs_extent_save_path(ext2_extent_handle_t handle,
                                  ext2_extent_path_t *ret_path)
 {
@@ -552,25 +641,58 @@ errcode_t ext2fs_extent_free_path(ext2_extent_path_t path)
        ext2fs_free_mem(&path);
        return 0;
 }
+#endif
 
-static errcode_t extent_goto(ext2_extent_handle_t handle,
-                            int leaf_level, blk64_t blk)
+/*
+ * Go to the node at leaf_level which contains logical block blk.
+ *
+ * leaf_level is height from the leaf node level, i.e.
+ * leaf_level 0 is at leaf node, leaf_level 1 is 1 above etc.
+ *
+ * If "blk" has no mapping (hole) then handle is left at last
+ * extent before blk.
+ */
+errcode_t ext2fs_extent_goto2(ext2_extent_handle_t handle,
+                             int leaf_level, blk64_t blk)
 {
-       struct ext2fs_extent    extent, next;
+       struct ext2fs_extent    extent;
        errcode_t               retval;
 
        retval = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
-       if (retval)
+       if (retval) {
+               if (retval == EXT2_ET_EXTENT_NO_NEXT)
+                       retval = EXT2_ET_EXTENT_NOT_FOUND;
                return retval;
+       }
+
+       if (leaf_level > handle->max_depth) {
+#ifdef DEBUG
+               printf("leaf level %d greater than tree depth %d\n",
+                       leaf_level, handle->max_depth);
+#endif
+               return EXT2_ET_OP_NOT_SUPPORTED;
+       }
+
+#ifdef DEBUG
+       printf("goto extent ino %u, level %d, %llu\n", handle->ino,
+              leaf_level, blk);
+#endif
 
+#ifdef DEBUG_GOTO_EXTENTS
        dbg_print_extent("root", &extent);
+#endif
        while (1) {
-               if (handle->level - leaf_level == handle->max_depth) {
+               if (handle->max_depth - handle->level == leaf_level) {
+                       /* block is in this &extent */
                        if ((blk >= extent.e_lblk) &&
                            (blk < extent.e_lblk + extent.e_len))
                                return 0;
-                       if (blk < extent.e_lblk)
+                       if (blk < extent.e_lblk) {
+                               retval = ext2fs_extent_get(handle,
+                                                          EXT2_EXTENT_PREV_SIB,
+                                                          &extent);
                                return EXT2_ET_EXTENT_NOT_FOUND;
+                       }
                        retval = ext2fs_extent_get(handle,
                                                   EXT2_EXTENT_NEXT_SIB,
                                                   &extent);
@@ -588,7 +710,9 @@ static errcode_t extent_goto(ext2_extent_handle_t handle,
                if (retval)
                        return retval;
 
+#ifdef DEBUG_GOTO_EXTENTS
                dbg_print_extent("next", &extent);
+#endif
                if (blk == extent.e_lblk)
                        goto go_down;
                if (blk > extent.e_lblk)
@@ -599,7 +723,9 @@ static errcode_t extent_goto(ext2_extent_handle_t handle,
                if (retval)
                        return retval;
 
+#ifdef DEBUG_GOTO_EXTENTS
                dbg_print_extent("prev", &extent);
+#endif
 
        go_down:
                retval = ext2fs_extent_get(handle, EXT2_EXTENT_DOWN,
@@ -607,17 +733,91 @@ static errcode_t extent_goto(ext2_extent_handle_t handle,
                if (retval)
                        return retval;
 
+#ifdef DEBUG_GOTO_EXTENTS
                dbg_print_extent("down", &extent);
+#endif
        }
 }
 
 errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
                             blk64_t blk)
 {
-       return extent_goto(handle, 0, blk);
+       return ext2fs_extent_goto2(handle, 0, blk);
+}
+
+/*
+ * Traverse back up to root fixing parents of current node as needed.
+ *
+ * If we changed start of first entry in a node, fix parent index start
+ * and so on.
+ *
+ * Safe to call for any position in node; if not at the first entry,
+ * it will simply return.
+ *
+ * Note a subtlety of this function -- if there happen to be two extents
+ * mapping the same lblk and someone calls fix_parents on the second of the two
+ * extents, the position of the extent handle after the call will be the second
+ * extent if nothing happened, or the first extent if something did.  A caller
+ * in this situation must use ext2fs_extent_goto() after calling this function.
+ * Or simply don't map the same lblk with two extents, ever.
+ */
+errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle)
+{
+       int                             retval = 0;
+       int                             orig_height;
+       blk64_t                         start;
+       struct extent_path              *path;
+       struct ext2fs_extent            extent;
+       struct ext2_extent_info         info;
+
+       EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
+
+       if (!(handle->fs->flags & EXT2_FLAG_RW))
+               return EXT2_ET_RO_FILSYS;
+
+       if (!handle->path)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       path = handle->path + handle->level;
+       if (!path->curr)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
+       if (retval)
+               goto done;
+
+       /* modified node's start block */
+       start = extent.e_lblk;
+
+       if ((retval = ext2fs_extent_get_info(handle, &info)))
+               return retval;
+       orig_height = info.max_depth - info.curr_level;
+
+       /* traverse up until index not first, or startblk matches, or top */
+       while (handle->level > 0 &&
+              (path->left == path->entries - 1)) {
+               retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
+               if (retval)
+                       goto done;
+               if (extent.e_lblk == start)
+                       break;
+               path = handle->path + handle->level;
+               extent.e_len += (extent.e_lblk - start);
+               extent.e_lblk = start;
+               retval = ext2fs_extent_replace(handle, 0, &extent);
+               if (retval)
+                       goto done;
+               update_path(handle);
+       }
+
+       /* put handle back to where we started */
+       retval = ext2fs_extent_goto2(handle, orig_height, start);
+done:
+       return retval;
 }
 
-errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, int flags,
+errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
+                               int flags EXT2FS_ATTR((unused)),
                                struct ext2fs_extent *extent)
 {
        struct extent_path              *path;
@@ -636,13 +836,27 @@ errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, int flags,
        if (!path->curr)
                return EXT2_ET_NO_CURRENT_NODE;
 
+#ifdef DEBUG
+       printf("extent replace: %u ", handle->ino);
+       dbg_print_extent(0, extent);
+#endif
+
        if (handle->level == handle->max_depth) {
                ex = path->curr;
 
                ex->ee_block = ext2fs_cpu_to_le32(extent->e_lblk);
                ex->ee_start = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
                ex->ee_start_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
-               ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
+               if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT) {
+                       if (extent->e_len > EXT_UNINIT_MAX_LEN)
+                               return EXT2_ET_EXTENT_INVALID_LENGTH;
+                       ex->ee_len = ext2fs_cpu_to_le16(extent->e_len +
+                                                       EXT_INIT_MAX_LEN);
+               } else {
+                       if (extent->e_len > EXT_INIT_MAX_LEN)
+                               return EXT2_ET_EXTENT_INVALID_LENGTH;
+                       ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
+               }
        } else {
                ix = path->curr;
 
@@ -655,6 +869,291 @@ errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, int flags,
        return 0;
 }
 
+static int splitting_at_eof(struct ext2_extent_handle *handle,
+                           struct extent_path *path)
+{
+       struct extent_path *ppp = path;
+       dump_path(__func__, handle, path);
+
+       if (handle->level == 0)
+               return 0;
+
+       do {
+               if (ppp->left)
+                       return 0;
+               ppp--;
+       } while (ppp >= handle->path);
+
+       return 1;
+}
+
+/*
+ * allocate a new block, move half the current node to it, and update parent
+ *
+ * handle will be left pointing at original record.
+ */
+static errcode_t extent_node_split(ext2_extent_handle_t handle,
+                                  int expand_allowed)
+{
+       errcode_t                       retval = 0;
+       blk64_t                         new_node_pblk;
+       blk64_t                         new_node_start;
+       blk64_t                         orig_lblk;
+       blk64_t                         goal_blk = 0;
+       int                             orig_height;
+       char                            *block_buf = NULL;
+       struct ext2fs_extent            extent;
+       struct extent_path              *path, *newpath = 0;
+       struct ext3_extent_header       *eh, *neweh;
+       int                             tocopy;
+       int                             new_root = 0;
+       struct ext2_extent_info         info;
+       int                             no_balance;
+
+       /* basic sanity */
+       EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
+
+       if (!(handle->fs->flags & EXT2_FLAG_RW))
+               return EXT2_ET_RO_FILSYS;
+
+       if (!handle->path)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+#ifdef DEBUG
+       printf("splitting node at level %d\n", handle->level);
+#endif
+       retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
+       if (retval)
+               goto done;
+
+       retval = ext2fs_extent_get_info(handle, &info);
+       if (retval)
+               goto done;
+
+       /* save the position we were originally splitting... */
+       orig_height = info.max_depth - info.curr_level;
+       orig_lblk = extent.e_lblk;
+
+       /* Try to put the index block before the first extent */
+       path = handle->path + handle->level;
+       eh = (struct ext3_extent_header *) path->buf;
+       if (handle->level == handle->max_depth) {
+               struct ext3_extent      *ex;
+
+               ex = EXT_FIRST_EXTENT(eh);
+               goal_blk = ext2fs_le32_to_cpu(ex->ee_start) +
+                       ((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
+       } else {
+               struct ext3_extent_idx  *ix;
+
+               ix = EXT_FIRST_INDEX(eh);
+               goal_blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
+                       ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
+       }
+       goal_blk -= EXT2FS_CLUSTER_RATIO(handle->fs);
+       goal_blk &= ~EXT2FS_CLUSTER_MASK(handle->fs);
+
+       /* Is there room in the parent for a new entry? */
+       if (handle->level &&
+                       (handle->path[handle->level - 1].entries >=
+                        handle->path[handle->level - 1].max_entries)) {
+
+#ifdef DEBUG
+               printf("parent level %d full; splitting it too\n",
+                                                       handle->level - 1);
+#endif
+               /* split the parent */
+               retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
+               if (retval)
+                       goto done;
+
+               retval = extent_node_split(handle, expand_allowed);
+               if (retval)
+                       goto done;
+
+               /* get handle back to our original split position */
+               retval = ext2fs_extent_goto2(handle, orig_height, orig_lblk);
+               if (retval)
+                       goto done;
+       }
+
+       /* At this point, parent should have room for this split */
+       path = handle->path + handle->level;
+       if (!path->curr)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       /*
+        * Normally, we try to split a full node in half.  This doesn't turn
+        * out so well if we're tacking extents on the end of the file because
+        * then we're stuck with a tree of half-full extent blocks.  This of
+        * course doesn't apply to the root level.
+        */
+       no_balance = expand_allowed ? splitting_at_eof(handle, path) : 0;
+
+       /* extent header of the current node we'll split */
+       eh = (struct ext3_extent_header *)path->buf;
+
+       /* splitting root level means moving them all out */
+       if (handle->level == 0) {
+               new_root = 1;
+               tocopy = ext2fs_le16_to_cpu(eh->eh_entries);
+               retval = ext2fs_get_memzero((handle->max_paths + 1) *
+                                           sizeof(struct extent_path),
+                                           &newpath);
+               if (retval)
+                       goto done;
+       } else {
+               if (no_balance)
+                       tocopy = 1;
+               else
+                       tocopy = ext2fs_le16_to_cpu(eh->eh_entries) / 2;
+       }
+
+#ifdef DEBUG
+       printf("will copy out %d of %d entries at level %d\n",
+                               tocopy, ext2fs_le16_to_cpu(eh->eh_entries),
+                               handle->level);
+#endif
+
+       if (!tocopy && !no_balance) {
+#ifdef DEBUG
+               printf("Nothing to copy to new block!\n");
+#endif
+               retval = EXT2_ET_CANT_SPLIT_EXTENT;
+               goto done;
+       }
+
+       /* first we need a new block, or can do nothing. */
+       block_buf = malloc(handle->fs->blocksize);
+       if (!block_buf) {
+               retval = ENOMEM;
+               goto done;
+       }
+
+       if (!goal_blk)
+               goal_blk = ext2fs_find_inode_goal(handle->fs, handle->ino,
+                                                 handle->inode, 0);
+       retval = ext2fs_alloc_block2(handle->fs, goal_blk, block_buf,
+                                   &new_node_pblk);
+       if (retval)
+               goto done;
+
+#ifdef DEBUG
+       printf("will copy to new node at block %lu\n",
+              (unsigned long) new_node_pblk);
+#endif
+
+       /* Copy data into new block buffer */
+       /* First the header for the new block... */
+       neweh = (struct ext3_extent_header *) block_buf;
+       memcpy(neweh, eh, sizeof(struct ext3_extent_header));
+       neweh->eh_entries = ext2fs_cpu_to_le16(tocopy);
+       neweh->eh_max = ext2fs_cpu_to_le16((handle->fs->blocksize -
+                        sizeof(struct ext3_extent_header)) /
+                               sizeof(struct ext3_extent));
+
+       /* then the entries for the new block... */
+       memcpy(EXT_FIRST_INDEX(neweh),
+               EXT_FIRST_INDEX(eh) +
+                       (ext2fs_le16_to_cpu(eh->eh_entries) - tocopy),
+               sizeof(struct ext3_extent_idx) * tocopy);
+
+       new_node_start = ext2fs_le32_to_cpu(EXT_FIRST_INDEX(neweh)->ei_block);
+
+       /* then update the checksum */
+       retval = ext2fs_extent_block_csum_set(handle->fs, handle->ino, neweh);
+       if (retval)
+               goto done;
+
+       /* ...and write the new node block out to disk. */
+       retval = io_channel_write_blk64(handle->fs->io, new_node_pblk, 1,
+                                       block_buf);
+
+       if (retval)
+               goto done;
+
+       /* OK! we've created the new node; now adjust the tree */
+
+       /* current path now has fewer active entries, we copied some out */
+       if (handle->level == 0) {
+               memcpy(newpath, path,
+                      sizeof(struct extent_path) * handle->max_paths);
+               handle->path = newpath;
+               newpath = path;
+               path = handle->path;
+               path->entries = 1;
+               path->left = path->max_entries - 1;
+               handle->max_depth++;
+               handle->max_paths++;
+               eh->eh_depth = ext2fs_cpu_to_le16(handle->max_depth);
+       } else {
+               path->entries -= tocopy;
+               path->left -= tocopy;
+       }
+
+       eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
+       /* this writes out the node, incl. the modified header */
+       retval = update_path(handle);
+       if (retval)
+               goto done;
+
+       /* now go up and insert/replace index for new node we created */
+       if (new_root) {
+               retval = ext2fs_extent_get(handle, EXT2_EXTENT_FIRST_SIB, &extent);
+               if (retval)
+                       goto done;
+
+               extent.e_lblk = new_node_start;
+               extent.e_pblk = new_node_pblk;
+               extent.e_len = handle->path[0].end_blk - extent.e_lblk;
+               retval = ext2fs_extent_replace(handle, 0, &extent);
+               if (retval)
+                       goto done;
+       } else {
+               __u32 new_node_length;
+
+               retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
+               /* will insert after this one; it's length is shorter now */
+               new_node_length = new_node_start - extent.e_lblk;
+               extent.e_len -= new_node_length;
+               retval = ext2fs_extent_replace(handle, 0, &extent);
+               if (retval)
+                       goto done;
+
+               /* now set up the new extent and insert it */
+               extent.e_lblk = new_node_start;
+               extent.e_pblk = new_node_pblk;
+               extent.e_len = new_node_length;
+               retval = ext2fs_extent_insert(handle, EXT2_EXTENT_INSERT_AFTER, &extent);
+               if (retval)
+                       goto done;
+       }
+
+       /* get handle back to our original position */
+       retval = ext2fs_extent_goto2(handle, orig_height, orig_lblk);
+       if (retval)
+               goto done;
+
+       /* new node hooked in, so update inode block count (do this here?) */
+       ext2fs_iblk_add_blocks(handle->fs, handle->inode, 1);
+       retval = ext2fs_write_inode(handle->fs, handle->ino,
+                                   handle->inode);
+       if (retval)
+               goto done;
+
+done:
+       if (newpath)
+               ext2fs_free_mem(&newpath);
+       free(block_buf);
+
+       return retval;
+}
+
+errcode_t ext2fs_extent_node_split(ext2_extent_handle_t handle)
+{
+       return extent_node_split(handle, 0);
+}
+
 errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
                                      struct ext2fs_extent *extent)
 {
@@ -671,10 +1170,27 @@ errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
        if (!handle->path)
                return EXT2_ET_NO_CURRENT_NODE;
 
+#ifdef DEBUG
+       printf("extent insert: %u ", handle->ino);
+       dbg_print_extent(0, extent);
+#endif
+
        path = handle->path + handle->level;
 
-       if (path->entries >= path->max_entries)
-               return EXT2_ET_CANT_INSERT_EXTENT;
+       if (path->entries >= path->max_entries) {
+               if (flags & EXT2_EXTENT_INSERT_NOSPLIT) {
+                       return EXT2_ET_CANT_INSERT_EXTENT;
+               } else {
+#ifdef DEBUG
+                       printf("node full (level %d) - splitting\n",
+                                  handle->level);
+#endif
+                       retval = extent_node_split(handle, 1);
+                       if (retval)
+                               return retval;
+                       path = handle->path + handle->level;
+               }
+       }
 
        eh = (struct ext3_extent_header *) path->buf;
        if (path->curr) {
@@ -683,14 +1199,16 @@ errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
                        ix++;
                        path->left--;
                }
-       } else
+       } else {
                ix = EXT_FIRST_INDEX(eh);
+               path->left = -1;
+       }
 
        path->curr = ix;
 
-       if (path->left > 0)
+       if (path->left >= 0)
                memmove(ix + 1, ix,
-                       path->left * sizeof(struct ext3_extent_idx));
+                       (path->left+1) * sizeof(struct ext3_extent_idx));
        path->left++;
        path->entries++;
 
@@ -712,15 +1230,53 @@ errout:
        return retval;
 }
 
-errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
+/*
+ * Sets the physical block for a logical file block in the extent tree.
+ *
+ * May: map unmapped, unmap mapped, or remap mapped blocks.
+ *
+ * Mapping an unmapped block adds a single-block extent.
+ *
+ * Unmapping first or last block modifies extent in-place
+ *  - But may need to fix parent's starts too in first-block case
+ *
+ * Mapping any unmapped block requires adding a (single-block) extent
+ * and inserting into proper point in tree.
+ *
+ * Modifying (unmapping or remapping) a block in the middle
+ * of an extent requires splitting the extent.
+ *  - Remapping case requires new single-block extent.
+ *
+ * Remapping first or last block adds an extent.
+ *
+ * We really need extent adding to be smart about merging.
+ */
+
+errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
+                                blk64_t logical, blk64_t physical, int flags)
 {
-       struct extent_path              *path;
-       char                            *cp;
-       struct ext3_extent_header       *eh;
-       errcode_t                       retval;
+       errcode_t               ec, retval = 0;
+       int                     mapped = 1; /* logical is mapped? */
+       int                     orig_height;
+       int                     extent_uninit = 0;
+       int                     prev_uninit = 0;
+       int                     next_uninit = 0;
+       int                     new_uninit = 0;
+       int                     max_len = EXT_INIT_MAX_LEN;
+       int                     has_prev, has_next;
+       blk64_t                 orig_lblk;
+       struct extent_path      *path;
+       struct ext2fs_extent    extent, next_extent, prev_extent;
+       struct ext2fs_extent    newextent;
+       struct ext2_extent_info info;
 
        EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 
+#ifdef DEBUG
+       printf("set_bmap ino %u log %lld phys %lld flags %d\n",
+              handle->ino, logical, physical, flags);
+#endif
+
        if (!(handle->fs->flags & EXT2_FLAG_RW))
                return EXT2_ET_RO_FILSYS;
 
@@ -728,13 +1284,354 @@ errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
                return EXT2_ET_NO_CURRENT_NODE;
 
        path = handle->path + handle->level;
-       if (!path->curr)
-               return EXT2_ET_NO_CURRENT_NODE;
 
-       cp = path->curr;
+       if (flags & EXT2_EXTENT_SET_BMAP_UNINIT) {
+               new_uninit = 1;
+               max_len = EXT_UNINIT_MAX_LEN;
+       }
 
-       if (path->left) {
-               memmove(cp, cp + sizeof(struct ext3_extent_idx),
+       /* if (re)mapping, set up new extent to insert */
+       if (physical) {
+               newextent.e_len = 1;
+               newextent.e_pblk = physical;
+               newextent.e_lblk = logical;
+               newextent.e_flags = EXT2_EXTENT_FLAGS_LEAF;
+               if (new_uninit)
+                       newextent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+       }
+
+       /* special case if the extent tree is completely empty */
+       if ((handle->max_depth == 0) && (path->entries == 0)) {
+               retval = ext2fs_extent_insert(handle, 0, &newextent);
+               return retval;
+       }
+
+       /* save our original location in the extent tree */
+       if ((retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
+                                       &extent))) {
+               if (retval != EXT2_ET_NO_CURRENT_NODE)
+                       return retval;
+               memset(&extent, 0, sizeof(extent));
+       }
+       if ((retval = ext2fs_extent_get_info(handle, &info)))
+               return retval;
+       orig_height = info.max_depth - info.curr_level;
+       orig_lblk = extent.e_lblk;
+
+       /* go to the logical spot we want to (re/un)map */
+       retval = ext2fs_extent_goto(handle, logical);
+       if (retval) {
+               if (retval == EXT2_ET_EXTENT_NOT_FOUND) {
+                       retval = 0;
+                       mapped = 0;
+                       if (!physical) {
+#ifdef DEBUG
+                               printf("block %llu already unmapped\n",
+                                       logical);
+#endif
+                               goto done;
+                       }
+               } else
+                       goto done;
+       }
+
+       /*
+        * This may be the extent *before* the requested logical,
+        * if it's currently unmapped.
+        *
+        * Get the previous and next leaf extents, if they are present.
+        */
+       retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
+       if (retval)
+               goto done;
+       if (extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+               extent_uninit = 1;
+       retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF, &next_extent);
+       if (retval) {
+               has_next = 0;
+               if (retval != EXT2_ET_EXTENT_NO_NEXT)
+                       goto done;
+       } else {
+               dbg_print_extent("set_bmap: next_extent",
+                                &next_extent);
+               has_next = 1;
+               if (next_extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+                       next_uninit = 1;
+       }
+       retval = ext2fs_extent_goto(handle, logical);
+       if (retval && retval != EXT2_ET_EXTENT_NOT_FOUND)
+               goto done;
+       retval = ext2fs_extent_get(handle, EXT2_EXTENT_PREV_LEAF, &prev_extent);
+       if (retval) {
+               has_prev = 0;
+               if (retval != EXT2_ET_EXTENT_NO_PREV)
+                       goto done;
+       } else {
+               has_prev = 1;
+               dbg_print_extent("set_bmap: prev_extent",
+                                &prev_extent);
+               if (prev_extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+                       prev_uninit = 1;
+       }
+       retval = ext2fs_extent_goto(handle, logical);
+       if (retval && retval != EXT2_ET_EXTENT_NOT_FOUND)
+               goto done;
+
+       /* check if already pointing to the requested physical */
+       if (mapped && (new_uninit == extent_uninit) &&
+           (extent.e_pblk + (logical - extent.e_lblk) == physical)) {
+#ifdef DEBUG
+               printf("physical block (at %llu) unchanged\n", logical);
+#endif
+               goto done;
+       }
+
+       if (!mapped) {
+#ifdef DEBUG
+               printf("mapping unmapped logical block %llu\n", logical);
+#endif
+               if ((logical == extent.e_lblk + extent.e_len) &&
+                   (physical == extent.e_pblk + extent.e_len) &&
+                   (new_uninit == extent_uninit) &&
+                   ((int) extent.e_len < max_len-1)) {
+                       extent.e_len++;
+                       retval = ext2fs_extent_replace(handle, 0, &extent);
+               } else if ((logical == extent.e_lblk - 1) &&
+                          (physical == extent.e_pblk - 1) &&
+                          (new_uninit == extent_uninit) &&
+                          ((int) extent.e_len < max_len - 1)) {
+                       extent.e_len++;
+                       extent.e_lblk--;
+                       extent.e_pblk--;
+                       retval = ext2fs_extent_replace(handle, 0, &extent);
+               } else if (has_next &&
+                          (logical == next_extent.e_lblk - 1) &&
+                          (physical == next_extent.e_pblk - 1) &&
+                          (new_uninit == next_uninit) &&
+                          ((int) next_extent.e_len < max_len - 1)) {
+                       retval = ext2fs_extent_get(handle,
+                                                  EXT2_EXTENT_NEXT_LEAF,
+                                                  &next_extent);
+                       if (retval)
+                               goto done;
+                       next_extent.e_len++;
+                       next_extent.e_lblk--;
+                       next_extent.e_pblk--;
+                       retval = ext2fs_extent_replace(handle, 0, &next_extent);
+               } else if (logical < extent.e_lblk)
+                       retval = ext2fs_extent_insert(handle, 0, &newextent);
+               else
+                       retval = ext2fs_extent_insert(handle,
+                                     EXT2_EXTENT_INSERT_AFTER, &newextent);
+               if (retval)
+                       goto done;
+               retval = ext2fs_extent_fix_parents(handle);
+               if (retval)
+                       goto done;
+       } else if ((logical == extent.e_lblk) && (extent.e_len == 1))  {
+#ifdef DEBUG
+               printf("(re/un)mapping only block in extent\n");
+#endif
+               if (physical) {
+                       retval = ext2fs_extent_replace(handle, 0, &newextent);
+               } else {
+                       retval = ext2fs_extent_delete(handle, 0);
+                       if (retval)
+                               goto done;
+                       ec = ext2fs_extent_fix_parents(handle);
+                       if (ec != EXT2_ET_NO_CURRENT_NODE)
+                               retval = ec;
+               }
+
+               if (retval)
+                       goto done;
+       } else if (logical == extent.e_lblk + extent.e_len - 1)  {
+#ifdef DEBUG
+               printf("(re/un)mapping last block in extent\n");
+#endif
+               if (physical) {
+                       if (has_next &&
+                           (logical == (next_extent.e_lblk - 1)) &&
+                           (physical == (next_extent.e_pblk - 1)) &&
+                           (new_uninit == next_uninit) &&
+                           ((int) next_extent.e_len < max_len - 1)) {
+                               retval = ext2fs_extent_get(handle,
+                                       EXT2_EXTENT_NEXT_LEAF, &next_extent);
+                               if (retval)
+                                       goto done;
+                               next_extent.e_len++;
+                               next_extent.e_lblk--;
+                               next_extent.e_pblk--;
+                               retval = ext2fs_extent_replace(handle, 0,
+                                                              &next_extent);
+                               if (retval)
+                                       goto done;
+                       } else
+                               retval = ext2fs_extent_insert(handle,
+                                     EXT2_EXTENT_INSERT_AFTER, &newextent);
+                       if (retval)
+                               goto done;
+                       retval = ext2fs_extent_fix_parents(handle);
+                       if (retval)
+                               goto done;
+                       /*
+                        * Now pointing at inserted extent; move back to prev.
+                        *
+                        * We cannot use EXT2_EXTENT_PREV to go back; note the
+                        * subtlety in the comment for fix_parents().
+                        */
+                       retval = ext2fs_extent_goto(handle, logical);
+                       if (retval)
+                               goto done;
+                       retval = ext2fs_extent_get(handle,
+                                                  EXT2_EXTENT_CURRENT,
+                                                  &extent);
+                       if (retval)
+                               goto done;
+               }
+               extent.e_len--;
+               retval = ext2fs_extent_replace(handle, 0, &extent);
+               if (retval)
+                       goto done;
+       } else if (logical == extent.e_lblk) {
+#ifdef DEBUG
+               printf("(re/un)mapping first block in extent\n");
+#endif
+               if (physical) {
+                       if (has_prev &&
+                           (logical == (prev_extent.e_lblk +
+                                        prev_extent.e_len)) &&
+                           (physical == (prev_extent.e_pblk +
+                                         prev_extent.e_len)) &&
+                           (new_uninit == prev_uninit) &&
+                           ((int) prev_extent.e_len < max_len-1)) {
+                               retval = ext2fs_extent_get(handle, 
+                                       EXT2_EXTENT_PREV_LEAF, &prev_extent);
+                               if (retval)
+                                       goto done;
+                               prev_extent.e_len++;
+                               retval = ext2fs_extent_replace(handle, 0,
+                                                              &prev_extent);
+                       } else
+                               retval = ext2fs_extent_insert(handle,
+                                                             0, &newextent);
+                       if (retval)
+                               goto done;
+                       retval = ext2fs_extent_fix_parents(handle);
+                       if (retval)
+                               goto done;
+                       retval = ext2fs_extent_get(handle,
+                                                  EXT2_EXTENT_NEXT_LEAF,
+                                                  &extent);
+                       if (retval)
+                               goto done;
+               }
+               extent.e_pblk++;
+               extent.e_lblk++;
+               extent.e_len--;
+               retval = ext2fs_extent_replace(handle, 0, &extent);
+               if (retval)
+                       goto done;
+               retval = ext2fs_extent_fix_parents(handle);
+               if (retval)
+                       goto done;
+       } else {
+               __u32   save_length;
+               blk64_t save_lblk;
+               struct ext2fs_extent save_extent;
+               errcode_t r2;
+
+#ifdef DEBUG
+               printf("(re/un)mapping in middle of extent\n");
+#endif
+               /* need to split this extent; later */
+               save_lblk = extent.e_lblk;
+               save_length = extent.e_len;
+               save_extent = extent;
+
+               /* shorten pre-split extent */
+               extent.e_len = (logical - extent.e_lblk);
+               retval = ext2fs_extent_replace(handle, 0, &extent);
+               if (retval)
+                       goto done;
+               /* insert our new extent, if any */
+               if (physical) {
+                       /* insert new extent after current */
+                       retval = ext2fs_extent_insert(handle,
+                                       EXT2_EXTENT_INSERT_AFTER, &newextent);
+                       if (retval) {
+                               r2 = ext2fs_extent_goto(handle, save_lblk);
+                               if (r2 == 0)
+                                       (void)ext2fs_extent_replace(handle, 0,
+                                                             &save_extent);
+                               goto done;
+                       }
+               }
+               /* add post-split extent */
+               extent.e_pblk += extent.e_len + 1;
+               extent.e_lblk += extent.e_len + 1;
+               extent.e_len = save_length - extent.e_len - 1;
+               retval = ext2fs_extent_insert(handle,
+                               EXT2_EXTENT_INSERT_AFTER, &extent);
+               if (retval) {
+                       if (physical) {
+                               r2 = ext2fs_extent_goto(handle,
+                                                       newextent.e_lblk);
+                               if (r2 == 0)
+                                       (void)ext2fs_extent_delete(handle, 0);
+                       }
+                       r2 = ext2fs_extent_goto(handle, save_lblk);
+                       if (r2 == 0)
+                               (void)ext2fs_extent_replace(handle, 0,
+                                                           &save_extent);
+                       goto done;
+               }
+       }
+
+done:
+       /* get handle back to its position */
+       if (orig_height > handle->max_depth)
+               orig_height = handle->max_depth; /* In case we shortened the tree */
+       ext2fs_extent_goto2(handle, orig_height, orig_lblk);
+       return retval;
+}
+
+errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
+{
+       struct extent_path              *path;
+       char                            *cp;
+       struct ext3_extent_header       *eh;
+       errcode_t                       retval = 0;
+
+       EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
+
+       if (!(handle->fs->flags & EXT2_FLAG_RW))
+               return EXT2_ET_RO_FILSYS;
+
+       if (!handle->path)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+#ifdef DEBUG
+       {
+               struct ext2fs_extent    extent;
+
+               retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
+                                          &extent);
+               if (retval == 0) {
+                       printf("extent delete %u ", handle->ino);
+                       dbg_print_extent(0, &extent);
+               }
+       }
+#endif
+
+       path = handle->path + handle->level;
+       if (!path->curr)
+               return EXT2_ET_NO_CURRENT_NODE;
+
+       cp = path->curr;
+
+       if (path->left) {
+               memmove(cp, cp + sizeof(struct ext3_extent_idx),
                        path->left * sizeof(struct ext3_extent_idx));
                path->left--;
        } else {
@@ -742,15 +1639,37 @@ errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
                ix--;
                path->curr = ix;
        }
-       path->entries--;
-       if (path->entries == 0)
+       if (--path->entries == 0)
                path->curr = 0;
 
-       eh = (struct ext3_extent_header *) path->buf;
-       eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
+       /* if non-root node has no entries left, remove it & parent ptr to it */
+       if (path->entries == 0 && handle->level) {
+               if (!(flags & EXT2_EXTENT_DELETE_KEEP_EMPTY)) {
+                       struct ext2fs_extent    extent;
 
-       retval = update_path(handle);
+                       retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP,
+                                                               &extent);
+                       if (retval)
+                               return retval;
 
+                       retval = ext2fs_extent_delete(handle, flags);
+                       handle->inode->i_blocks -=
+                               (handle->fs->blocksize *
+                                EXT2FS_CLUSTER_RATIO(handle->fs)) / 512;
+                       retval = ext2fs_write_inode(handle->fs, handle->ino,
+                                                   handle->inode);
+                       ext2fs_block_alloc_stats2(handle->fs,
+                                                 extent.e_pblk, -1);
+               }
+       } else {
+               eh = (struct ext3_extent_header *) path->buf;
+               eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
+               if ((path->entries == 0) && (handle->level == 0)) {
+                       eh->eh_depth = 0;
+                       handle->max_depth = 0;
+               }
+               retval = update_path(handle);
+       }
        return retval;
 }
 
@@ -758,8 +1677,6 @@ errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
                                 struct ext2_extent_info *info)
 {
        struct extent_path              *path;
-       struct ext3_extent_idx          *ix;
-       struct ext3_extent              *ex;
 
        EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 
@@ -780,370 +1697,166 @@ errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
 
        info->curr_level = handle->level;
        info->max_depth = handle->max_depth;
-       info->max_lblk = ((__u64) 1 << 32) - 1;
-       info->max_pblk = ((__u64) 1 << 48) - 1;
-       info->max_len = (1UL << 15);
-       info->max_uninit_len = (1UL << 15) - 1;
+       info->max_lblk = EXT_MAX_EXTENT_LBLK;
+       info->max_pblk = EXT_MAX_EXTENT_PBLK;
+       info->max_len = EXT_INIT_MAX_LEN;
+       info->max_uninit_len = EXT_UNINIT_MAX_LEN;
 
        return 0;
 }
 
-#ifdef DEBUG
-
-#include "debugfs.h"
-
-/*
- * Hook in new commands into debugfs
- */
-char *debug_prog_name = "tst_extents";
-extern ss_request_table extent_cmds;
-ss_request_table *extra_cmds = &extent_cmds;
-
-ext2_ino_t     current_ino = 0;
-ext2_extent_handle_t current_handle;
-
-void do_inode(int argc, char *argv[])
+static int ul_log2(unsigned long arg)
 {
-       ext2_ino_t      inode;
-       int             i;
-       struct ext3_extent_header *eh;
-       errcode_t retval;
-
-       if (check_fs_open(argv[0]))
-               return;
-
-       if (argc == 1) {
-               if (current_ino)
-                       printf("Current inode is %d\n", current_ino);
-               else
-                       printf("No current inode\n");
-               return;
-       }
+       int     l = 0;
 
-       if (common_inode_args_process(argc, argv, &inode, 0)) {
-               return;
+       arg >>= 1;
+       while (arg) {
+               l++;
+               arg >>= 1;
        }
-
-       current_ino = 0;
-
-       retval = ext2fs_extent_open(current_fs, inode, &current_handle);
-       if (retval) {
-               com_err(argv[1], retval, "while opening extent handle");
-               return;
-       }
-
-       current_ino = inode;
-
-       printf("Loaded inode %d\n", current_ino);
-
-       return;
+       return l;
 }
 
-void generic_goto_node(char *cmd_name, int op)
+size_t ext2fs_max_extent_depth(ext2_extent_handle_t handle)
 {
-       struct ext2fs_extent    extent;
-       errcode_t               retval;
-
-       if (check_fs_open(cmd_name))
-               return;
-
-       if (!current_handle) {
-               com_err(cmd_name, 0, "Extent handle not open");
-               return;
-       }
-
-       retval = ext2fs_extent_get(current_handle, op, &extent);
-       if (retval) {
-               com_err(cmd_name, retval, 0);
-               return;
-       }
-       dbg_print_extent(0, &extent);
-}
-
-void do_current_node(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
-}
-
-void do_root_node(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_ROOT);
-}
-
-void do_last_leaf(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_LAST_LEAF);
-}
-
-void do_first_sib(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_FIRST_SIB);
-}
-
-void do_last_sib(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_LAST_SIB);
-}
-
-void do_next_sib(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_NEXT_SIB);
-}
-
-void do_prev_sib(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_PREV_SIB);
-}
-
-void do_next_leaf(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_NEXT_LEAF);
-}
-
-void do_prev_leaf(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_PREV_LEAF);
-}
-
-void do_next(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_NEXT);
-}
-
-void do_prev(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_PREV);
-}
-
-void do_up(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_UP);
-}
-
-void do_down(int argc, char *argv[])
-{
-       generic_goto_node(argv[0], EXT2_EXTENT_DOWN);
-}
-
-void do_delete_node(int argc, char *argv[])
-{
-       errcode_t       retval;
-       int             err;
-
-       if (check_fs_read_write(argv[0]))
-               return;
-
-       retval = ext2fs_extent_delete(current_handle, 0);
-       if (retval) {
-               com_err(argv[0], retval, 0);
-               return;
-       }
-       do_current_node(argc, argv);
+       size_t iblock_sz = sizeof(((struct ext2_inode *)NULL)->i_block);
+       size_t iblock_extents = (iblock_sz - sizeof(struct ext3_extent_header)) /
+                               sizeof(struct ext3_extent);
+       size_t extents_per_block = (handle->fs->blocksize -
+                                   sizeof(struct ext3_extent_header)) /
+                                  sizeof(struct ext3_extent);
+       static unsigned int last_blocksize = 0;
+       static size_t last_result = 0;
+
+       if (last_blocksize && last_blocksize == handle->fs->blocksize)
+               return last_result;
+
+       last_result = 1 + ((ul_log2(EXT_MAX_EXTENT_LBLK) - ul_log2(iblock_extents)) /
+                   ul_log2(extents_per_block));
+       last_blocksize = handle->fs->blocksize;
+       return last_result;
 }
 
-void do_replace_node(int argc, char *argv[])
+errcode_t ext2fs_fix_extents_checksums(ext2_filsys fs, ext2_ino_t ino,
+                                      struct ext2_inode *inode)
 {
-       errcode_t       retval;
-       struct ext2fs_extent extent;
-       int err;
-
-       if (check_fs_read_write(argv[0]))
-               return;
-
-       if (argc != 4) {
-               fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", argv[0]);
-               return;
+       ext2_extent_handle_t    handle;
+       struct ext2fs_extent    extent;
+       errcode_t               errcode;
+       int                     save_flags = fs->flags;
+
+       if (!ext2fs_has_feature_metadata_csum(fs->super) ||
+           (inode && !(inode->i_flags & EXT4_EXTENTS_FL)))
+               return 0;
+
+       errcode = ext2fs_extent_open2(fs, ino, inode, &handle);
+       if (errcode) {
+               if (errcode == EXT2_ET_INODE_NOT_EXTENT)
+                       errcode = 0;
+               return errcode;
        }
 
-       extent.e_lblk = parse_ulong(argv[1], argv[0],
-                                   "logical block", &err);
-       if (err)
-               return;
-
-       extent.e_len = parse_ulong(argv[2], argv[0],
-                                   "logical block", &err);
-       if (err)
-               return;
+       fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
+       errcode = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
+       if (errcode)
+               goto out;
+
+       do {
+               /* Skip to the end of a block of leaf nodes */
+               if (extent.e_flags & EXT2_EXTENT_FLAGS_LEAF) {
+                       errcode = ext2fs_extent_get(handle,
+                                                   EXT2_EXTENT_LAST_SIB,
+                                                   &extent);
+                       if (errcode)
+                               break;
+               }
 
-       extent.e_pblk = parse_ulong(argv[3], argv[0],
-                                   "logical block", &err);
-       if (err)
-               return;
+               errcode = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT, &extent);
+               if (errcode == EXT2_ET_EXTENT_CSUM_INVALID)
+                       errcode = update_path(handle);
+       } while (errcode == 0);
 
-       retval = ext2fs_extent_replace(current_handle, 0, &extent);
-       if (retval) {
-               com_err(argv[0], retval, 0);
-               return;
-       }
-       do_current_node(argc, argv);
+out:
+       /* Ok if we run off the end */
+       if (errcode == EXT2_ET_EXTENT_NO_NEXT)
+               errcode = 0;
+       ext2fs_extent_free(handle);
+       fs->flags = save_flags;
+       return errcode;
 }
 
-void do_insert_node(int argc, char *argv[])
+errcode_t ext2fs_decode_extent(struct ext2fs_extent *to, void *addr, int len)
 {
-       errcode_t       retval;
-       struct ext2fs_extent extent;
-       char *cmd;
-       int err;
-       int flags = 0;
-
-       if (check_fs_read_write(argv[0]))
-               return;
-
-       cmd = argv[0];
-
-       if (argc > 2 && !strcmp(argv[1], "--after")) {
-               argc--;
-               argv++;
-               flags |= EXT2_EXTENT_INSERT_AFTER;
-       }
-
-       if (argc != 4) {
-               fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", cmd);
-               return;
+       struct ext3_extent *from = (struct ext3_extent *)addr;
+
+       if (len != sizeof(struct ext3_extent))
+               return EXT2_ET_INVALID_ARGUMENT;
+
+       to->e_pblk = ext2fs_le32_to_cpu(from->ee_start) +
+               ((__u64) ext2fs_le16_to_cpu(from->ee_start_hi)
+                       << 32);
+       to->e_lblk = ext2fs_le32_to_cpu(from->ee_block);
+       to->e_len = ext2fs_le16_to_cpu(from->ee_len);
+       to->e_flags |= EXT2_EXTENT_FLAGS_LEAF;
+       if (to->e_len > EXT_INIT_MAX_LEN) {
+               to->e_len -= EXT_INIT_MAX_LEN;
+               to->e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
        }
 
-       extent.e_lblk = parse_ulong(argv[1], cmd,
-                                   "logical block", &err);
-       if (err)
-               return;
-
-       extent.e_len = parse_ulong(argv[2], cmd,
-                                   "length", &err);
-       if (err)
-               return;
-
-       extent.e_pblk = parse_ulong(argv[3], cmd,
-                                   "pysical block", &err);
-       if (err)
-               return;
-
-       retval = ext2fs_extent_insert(current_handle, flags, &extent);
-       if (retval) {
-               com_err(cmd, retval, 0);
-               return;
-       }
-       do_current_node(argc, argv);
+       return 0;
 }
 
-void do_print_all(int argc, char **argv)
+errcode_t ext2fs_count_blocks(ext2_filsys fs, ext2_ino_t ino,
+                             struct ext2_inode *inode, blk64_t *ret_count)
 {
+       ext2_extent_handle_t    handle = NULL;
        struct ext2fs_extent    extent;
-       errcode_t               retval;
-       errcode_t               end_err = EXT2_ET_EXTENT_NO_NEXT;
-       int                     op = EXT2_EXTENT_NEXT;
-       int                     first_op = EXT2_EXTENT_ROOT;
-
-
-       if (check_fs_open(argv[0]))
-               return;
-
-       if (!current_handle) {
-               com_err(argv[0], 0, "Extent handle not open");
-               return;
-       }
-
-       if (argc > 2) {
-       print_usage:
-               fprintf(stderr,
-                       "Usage: %s [--leaf-only|--reverse|--reverse-leaf]\n",
-                       argv[0]);
-               return;
-       }
-
-       if (argc == 2) {
-               if (!strcmp(argv[1], "--leaf-only"))
-                       op = EXT2_EXTENT_NEXT_LEAF;
-               else if (!strcmp(argv[1], "--reverse")) {
-                       op = EXT2_EXTENT_PREV;
-                       first_op = EXT2_EXTENT_LAST_LEAF;
-                       end_err = EXT2_ET_EXTENT_NO_PREV;
-               } else if (!strcmp(argv[1], "--reverse-leaf")) {
-                       op = EXT2_EXTENT_PREV_LEAF;
-                       first_op = EXT2_EXTENT_LAST_LEAF;
-                       end_err = EXT2_ET_EXTENT_NO_PREV;
-               } else
-                         goto print_usage;
-       }
-
-       retval = ext2fs_extent_get(current_handle, first_op, &extent);
-       if (retval) {
-               com_err(argv[0], retval, 0);
-               return;
-       }
-       dbg_print_extent(0, &extent);
-
-       while (1) {
-               retval = ext2fs_extent_get(current_handle, op, &extent);
-               if (retval == end_err)
-                       break;
-
-               if (retval) {
-                       com_err(argv[0], retval, 0);
-                       return;
+       errcode_t               errcode;
+       int                     i;
+       blk64_t                 blkcount = 0;
+       blk64_t                 *intermediate_nodes;
+
+       errcode = ext2fs_extent_open2(fs, ino, inode, &handle);
+       if (errcode)
+               goto out;
+
+       errcode = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
+       if (errcode)
+               goto out;
+
+       errcode = ext2fs_get_array(handle->max_depth, sizeof(blk64_t),
+                                  &intermediate_nodes);
+       if (errcode)
+               goto out;
+
+       blkcount = handle->level;
+       while (!errcode) {
+               if (extent.e_flags & EXT2_EXTENT_FLAGS_LEAF) {
+                       blkcount += extent.e_len;
+                       for (i = 0; i < handle->level; i++) {
+                               if (intermediate_nodes[i] !=
+                                       handle->path[i].end_blk) {
+                                       blkcount++;
+                                       intermediate_nodes[i] =
+                                               handle->path[i].end_blk;
+                               }
+                       }
                }
-               dbg_print_extent(0, &extent);
-       }
-}
-
-void do_info(int argc, char **argv)
-{
-       struct ext2_extent_info info;
-       errcode_t               retval;
-
-       if (check_fs_open(argv[0]))
-               return;
-
-       if (!current_handle) {
-               com_err(argv[0], 0, "Extent handle not open");
-               return;
-       }
-
-       retval = ext2fs_extent_get_info(current_handle, &info);
-       if (retval) {
-               com_err(argv[0], retval, 0);
-               return;
+               errcode = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT, &extent);
        }
+       ext2fs_free_mem(&intermediate_nodes);
+out:
+       *ret_count = blkcount;
+       ext2fs_extent_free(handle);
 
-       printf("Current handle location: %d/%d (max: %d, bytes %d), level %d/%d\n",
-              info.curr_entry, info.num_entries, info.max_entries,
-              info.bytes_avail, info.curr_level, info.max_depth);
-       printf("\tmax lblk: %llu, max pblk: %llu\n", info.max_lblk,
-              info.max_pblk);
-       printf("\tmax_len: %u, max_uninit_len: %u\n", info.max_len,
-              info.max_uninit_len);
+       return 0;
 }
 
-void do_goto_block(int argc, char **argv)
-{
-       struct ext2fs_extent    extent;
-       errcode_t               retval;
-       int                     op = EXT2_EXTENT_NEXT_LEAF;
-       blk_t                   blk;
-
-       if (check_fs_open(argv[0]))
-               return;
-
-       if (!current_handle) {
-               com_err(argv[0], 0, "Extent handle not open");
-               return;
-       }
-
-       if (argc != 2) {
-               fprintf(stderr, "%s block\n", argv[0]);
-               return;
-       }
-
-       if (strtoblk(argv[0], argv[1], &blk))
-               return;
-
-       retval = ext2fs_extent_goto(current_handle, (blk64_t) blk);
-       if (retval) {
-               com_err(argv[0], retval, "while trying to go to block %lu",
-                       blk);
-               return;
-       }
+#ifdef DEBUG
+/*
+ * Override debugfs's prompt
+ */
+const char *debug_prog_name = "tst_extents";
 
-       generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
-}
 #endif