X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lib%2Fext2fs%2Fextent.c;h=3df3092938cb0bbacc28f1d1a4f95075c2074f0c;hb=a9ea7285e6d97fba4fa4af059db73f0413acfcab;hp=e7b7e855602b357b24a634f440b98e7e1e60372a;hpb=c21ed7705be908a5697095e597849804302edd21;p=tools%2Fe2fsprogs.git

diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
index e7b7e85..3df3092 100644
--- a/lib/ext2fs/extent.c
+++ b/lib/ext2fs/extent.c
@@ -27,7 +27,6 @@
 #include "ext2_fs.h"
 #include "ext2fsP.h"
 #include "e2image.h"
-#include "ss/ss.h"
 
 /*
  * Definitions to be dropped in lib/ext2fs/ext2fs.h
@@ -74,21 +73,31 @@ 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)
@@ -110,13 +119,11 @@ static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
 
 }
 
-#define dbg_printf(fmt, args...) printf(fmt, ## args)
 #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)
 #endif
 
 /*
@@ -176,6 +183,7 @@ extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 	struct ext2_extent_handle	*handle;
 	errcode_t			retval;
 	int				isize = EXT2_INODE_SIZE(fs->super);
+	int				i;
 	struct ext3_extent_header	*eh;
 
 	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
@@ -199,14 +207,29 @@ extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 	if (retval)
 		goto errout;
 
-	if (!(handle->inode->i_flags & EXT4_EXTENTS_FL))
-		return EXT2_ET_INODE_NOT_EXTENT;
-
 	eh = (struct ext3_extent_header *) &handle->inode->i_block[0];
 
+	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;
+	}
+
+	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);
@@ -286,9 +309,11 @@ retry:
 				return EXT2_ET_EXTENT_NO_NEXT;
 		}
 		if (op != EXT2_EXTENT_NEXT_SIB) {
-			dbg_printf("<<<< OP = %s\n",
+#ifdef DEBUG
+			printf("<<<< OP = %s\n",
 			       (op == EXT2_EXTENT_DOWN) ? "down" :
 			       ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
+#endif
 		}
 	}
 
@@ -315,9 +340,11 @@ retry:
 				return EXT2_ET_EXTENT_NO_PREV;
 		}
 		if (op != EXT2_EXTENT_PREV_SIB) {
-			dbg_printf("<<<< OP = %s\n",
+#ifdef DEBUG
+			printf("<<<< OP = %s\n",
 			       (op == EXT2_EXTENT_DOWN_AND_LAST) ? "down/last" :
 			       ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
+#endif
 		}
 	}
 
@@ -327,8 +354,10 @@ retry:
 			op = EXT2_EXTENT_DOWN;
 		else
 			op = EXT2_EXTENT_LAST_SIB;
-		dbg_printf("<<<< OP = %s\n",
+#ifdef DEBUG
+		printf("<<<< OP = %s\n",
 			   (op == EXT2_EXTENT_DOWN) ? "down" : "last_sib");
+#endif
 	}
 
 	switch (op) {
@@ -438,11 +467,11 @@ retry:
 			if (handle->level < handle->max_depth)
 				path->visit_num = 1;
 		}
-
-		dbg_printf("Down to level %d/%d, end_blk=%llu\n",
+#ifdef DEBUG
+		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;
@@ -452,7 +481,9 @@ retry:
 		return EXT2_ET_NO_CURRENT_NODE;
 
 	extent->e_flags = 0;
-	dbg_printf("(Left %d)\n", path->left);
+#ifdef DEBUG
+	printf("(Left %d)\n", path->left);
+#endif
 
 	if (handle->level == handle->max_depth) {
 		ex = (struct ext3_extent *) ix;
@@ -556,6 +587,9 @@ errcode_t ext2fs_extent_free_path(ext2_extent_path_t path)
 /*
  * 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.
  */
@@ -569,9 +603,17 @@ static errcode_t extent_goto(ext2_extent_handle_t handle,
 	if (retval)
 		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;
+	}
+
 	dbg_print_extent("root", &extent);
 	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))
@@ -628,6 +670,64 @@ errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
 	return extent_goto(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,
+ * will  simply return.
+ */
+static errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle)
+{
+	int				retval = 0;
+	blk64_t				start;
+	struct extent_path		*path;
+	struct ext2fs_extent		extent;
+
+	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;
+
+	/* 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_goto(handle, start);
+done:
+	return retval;
+}
+
 errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle, 
 				int flags EXT2FS_ATTR((unused)),
 				struct ext2fs_extent *extent)
@@ -654,7 +754,16 @@ errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
 		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;
 
@@ -667,6 +776,238 @@ errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
 	return 0;
 }
 
+/*
+ * 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)
+{
+	errcode_t			retval = 0;
+	blk_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;
+
+	/* 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;
+
+	/* 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;
+		goal_blk = extent.e_pblk;
+
+		retval = extent_node_split(handle);
+		if (retval)
+			goto done;
+
+		/* get handle back to our original split position */
+		retval = extent_goto(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;
+
+	/* 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_mem(((handle->max_depth+2) *
+					 sizeof(struct extent_path)),
+					&newpath);
+		if (retval)
+			goto done;
+		memset(newpath, 0,
+		       ((handle->max_depth+2) * sizeof(struct extent_path)));
+	} 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) {
+#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) {
+		dgrp_t	group = ext2fs_group_of_ino(handle->fs, handle->ino);
+		__u8	log_flex = handle->fs->super->s_log_groups_per_flex;
+
+		if (log_flex)
+			group = group & ~((1 << (log_flex)) - 1);
+		goal_blk = (group * handle->fs->super->s_blocks_per_group) +
+			handle->fs->super->s_first_data_block;
+	}
+	retval = ext2fs_alloc_block(handle->fs, (blk_t) goal_blk, block_buf,
+				    &new_node_pblk);
+	if (retval)
+		goto done;
+
+#ifdef DEBUG
+	printf("will copy to new node at block %lu\n", 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);
+
+	/* ...and write the new node block out to disk. */
+	retval = io_channel_write_blk(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_depth+1));
+		handle->path = newpath;
+		newpath = path;
+		path = handle->path;
+		path->entries = 1;
+		path->left = path->max_entries - 1;
+		handle->max_depth++;
+		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 = extent_goto(handle, orig_height, orig_lblk);
+	if (retval)
+		goto done;
+
+	/* new node hooked in, so update inode block count (do this here?) */
+	handle->inode->i_blocks += handle->fs->blocksize / 512;
+	retval = ext2fs_write_inode_full(handle->fs, handle->ino,
+		handle->inode, EXT2_INODE_SIZE(handle->fs->super));
+	if (retval)
+		goto done;
+
+done:
+	if (newpath)
+		ext2fs_free_mem(&newpath);
+	if (block_buf)
+		free(block_buf);
+
+	return retval;
+}
+
 errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
 				      struct ext2fs_extent *extent)
 {
@@ -685,8 +1026,20 @@ errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
 
 	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);
+			if (retval)
+				goto errout;
+			path = handle->path + handle->level;
+		}
+	}
 
 	eh = (struct ext3_extent_header *) path->buf;
 	if (path->curr) {
@@ -724,13 +1077,242 @@ errout:
 	return retval;
 }
 
-errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, 
-			       int flags EXT2FS_ATTR((unused)))
+/*
+ * 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)
+{
+	errcode_t		ec, retval = 0;
+	int			mapped = 1; /* logical is mapped? */
+	int			orig_height;
+	int			extent_uninit = 0;
+	int			new_uninit = 0;
+	int			max_len = EXT_INIT_MAX_LEN;
+	blk64_t			orig_lblk;
+	struct extent_path	*path;
+	struct ext2fs_extent	extent;
+	struct ext2fs_extent	newextent;
+	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 (flags & EXT2_EXTENT_SET_BMAP_UNINIT) {
+		new_uninit = 1;
+		max_len = EXT_UNINIT_MAX_LEN;
+	}
+
+	/* 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.
+	 */
+	retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
+	if (retval)
+		goto done;
+	if (extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+		extent_uninit = 1;
+
+	/* 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)
+			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) {
+			extent.e_pblk = physical;
+			retval = ext2fs_extent_replace(handle, 0, &extent);
+		} 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
+		extent.e_len--;
+		retval = ext2fs_extent_replace(handle, 0, &extent);
+		if (retval)
+			goto done;
+		if (physical) {
+			retval = ext2fs_extent_insert(handle,
+					EXT2_EXTENT_INSERT_AFTER, &newextent);
+			if (retval)
+				goto done;
+		}
+	} else if (logical == extent.e_lblk) {
+#ifdef DEBUG
+		printf("(re/un)mapping first block in extent\n");
+#endif
+		extent.e_pblk++;
+		extent.e_lblk++;
+		extent.e_len--;
+		retval = ext2fs_extent_replace(handle, 0, &extent);
+		if (retval)
+			goto done;
+		if (physical) {
+			/* insert new extent ahead of current */
+			retval = ext2fs_extent_insert(handle,
+					0, &newextent);
+			if (retval)
+				goto done;
+		} else {
+			retval = ext2fs_extent_fix_parents(handle);
+			if (retval)
+				goto done;
+		}
+	} else {
+		__u32	orig_length;
+
+#ifdef DEBUG
+		printf("(re/un)mapping in middle of extent\n");
+#endif
+		/* need to split this extent; later */
+
+		orig_length = extent.e_len;
+
+		/* 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)
+				goto done;
+		}
+		/* add post-split extent */
+		extent.e_pblk += extent.e_len + 1;
+		extent.e_lblk += extent.e_len + 1;
+		extent.e_len = orig_length - extent.e_len - 1;
+		retval = ext2fs_extent_insert(handle,
+				EXT2_EXTENT_INSERT_AFTER, &extent);
+		if (retval)
+			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 */
+	extent_goto(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;
+	errcode_t			retval = 0;
 
 	EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 
@@ -755,15 +1337,33 @@ errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle,
 		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 / 512;
+			retval = ext2fs_write_inode_full(handle->fs,
+					handle->ino, handle->inode,
+					EXT2_INODE_SIZE(handle->fs->super));
+			ext2fs_block_alloc_stats(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 = handle->max_depth = 0;
+		retval = update_path(handle);
+	}
 	return retval;
 }
 
@@ -801,6 +1401,8 @@ errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
 
 #ifdef DEBUG
 
+#include "ss/ss.h"
+
 #include "debugfs.h"
 
 /*
@@ -813,6 +1415,21 @@ ss_request_table *extra_cmds = &extent_cmds;
 ext2_ino_t	current_ino = 0;
 ext2_extent_handle_t current_handle;
 
+int common_extent_args_process(int argc, char *argv[], int min_argc,
+			       int max_argc, const char *cmd,
+			       const char *usage, int flags)
+{
+	if (common_args_process(argc, argv, min_argc, max_argc, cmd,
+				usage, flags))
+		return 1;
+	
+	if (!current_handle) {
+		com_err(cmd, 0, "Extent handle not open");
+		return 1;
+	}
+	return 0;
+}
+
 void do_inode(int argc, char *argv[])
 {
 	ext2_ino_t	inode;
@@ -941,7 +1558,8 @@ void do_delete_node(int argc, char *argv[])
 	errcode_t	retval;
 	int		err;
 
-	if (check_fs_read_write(argv[0]))
+	if (common_extent_args_process(argc, argv, 1, 1, "delete_node",
+				       "", CHECK_FS_RW | CHECK_FS_BITMAPS))
 		return;
 
 	retval = ext2fs_extent_delete(current_handle, 0);
@@ -949,35 +1567,43 @@ void do_delete_node(int argc, char *argv[])
 		com_err(argv[0], retval, 0);
 		return;
 	}
-	do_current_node(argc, argv);
+	if (current_handle->path && current_handle->path[0].curr)
+		do_current_node(argc, argv);
 }
 
 void do_replace_node(int argc, char *argv[])
 {
+	const char	*usage = "[--uninit] <lblk> <len> <pblk>";
 	errcode_t	retval;
 	struct ext2fs_extent extent;
 	int err;
 
-	if (check_fs_read_write(argv[0]))
+	if (common_extent_args_process(argc, argv, 3, 5, "replace_node",
+				       usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
 		return;
 
+	extent.e_flags = 0;
+
+	if (!strcmp(argv[1], "--uninit")) {
+		argc--;
+		argv++;
+		extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+	}
+
 	if (argc != 4) {
-		fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", argv[0]);
+		fprintf(stderr, "Usage: %s %s\n", argv[0], usage);
 		return;
 	}
 
-	extent.e_lblk = parse_ulong(argv[1], argv[0],
-				    "logical block", &err);
+	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);
+	extent.e_len = parse_ulong(argv[2], argv[0], "logical block", &err);
 	if (err)
 		return;
 
-	extent.e_pblk = parse_ulong(argv[3], argv[0],
-				    "logical block", &err);
+	extent.e_pblk = parse_ulong(argv[3], argv[0], "logical block", &err);
 	if (err)
 		return;
 
@@ -989,27 +1615,59 @@ void do_replace_node(int argc, char *argv[])
 	do_current_node(argc, argv);
 }
 
+void do_split_node(int argc, char *argv[])
+{
+	errcode_t	retval;
+	struct ext2fs_extent extent;
+	int err;
+
+	if (common_extent_args_process(argc, argv, 1, 1, "split_node",
+				       "", CHECK_FS_RW | CHECK_FS_BITMAPS))
+		return;
+
+	retval = extent_node_split(current_handle);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+	do_current_node(argc, argv);
+}
+
 void do_insert_node(int argc, char *argv[])
 {
+	const char	*usage = "[--after] [--uninit] <lblk> <len> <pblk>";
 	errcode_t	retval;
 	struct ext2fs_extent extent;
 	char *cmd;
 	int err;
 	int flags = 0;
 
-	if (check_fs_read_write(argv[0]))
+	if (common_extent_args_process(argc, argv, 3, 6, "insert_node",
+				       usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
 		return;
 
 	cmd = argv[0];
 
-	if (argc > 2 && !strcmp(argv[1], "--after")) {
-		argc--;
-		argv++;
-		flags |= EXT2_EXTENT_INSERT_AFTER;
+	extent.e_flags = 0;
+
+	while (argc > 2) {
+		if (!strcmp(argv[1], "--after")) {
+			argc--;
+			argv++;
+			flags |= EXT2_EXTENT_INSERT_AFTER;
+			continue;
+		}
+		if (!strcmp(argv[1], "--uninit")) {
+			argc--;
+			argv++;
+			extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+			continue;
+		}
+		break;
 	}
 
 	if (argc != 4) {
-		fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", cmd);
+		fprintf(stderr, "usage: %s %s\n", cmd, usage);
 		return;
 	}
 
@@ -1036,8 +1694,54 @@ void do_insert_node(int argc, char *argv[])
 	do_current_node(argc, argv);
 }
 
+void do_set_bmap(int argc, char **argv)
+{
+	const char	*usage = "[--uninit] <lblk> <pblk>";
+	errcode_t	retval;
+	blk_t		logical;
+	blk_t		physical;
+	char		*cmd = argv[0];
+	int		flags = 0;
+	int		err;
+
+	if (common_extent_args_process(argc, argv, 3, 5, "set_bmap",
+				       usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
+		return;
+
+	if (argc > 2 && !strcmp(argv[1], "--uninit")) {
+		argc--;
+		argv++;
+		flags |= EXT2_EXTENT_SET_BMAP_UNINIT;
+	}
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s %s\n", cmd, usage);
+		return;
+	}
+
+	logical = parse_ulong(argv[1], cmd,
+				    "logical block", &err);
+	if (err)
+		return;
+
+	physical = parse_ulong(argv[2], cmd,
+				    "physical block", &err);
+	if (err)
+		return;
+
+	retval = ext2fs_extent_set_bmap(current_handle, logical,
+					(blk64_t) physical, flags);
+	if (retval) {
+		com_err(cmd, retval, 0);
+		return;
+	}
+	if (current_handle->path && current_handle->path[0].curr)
+		do_current_node(argc, argv);
+}
+
 void do_print_all(int argc, char **argv)
 {
+	const char	*usage = "[--leaf-only|--reverse|--reverse-leaf]";
 	struct ext2fs_extent	extent;
 	errcode_t		retval;
 	errcode_t		end_err = EXT2_ET_EXTENT_NO_NEXT;
@@ -1045,22 +1749,10 @@ void do_print_all(int argc, char **argv)
 	int			first_op = EXT2_EXTENT_ROOT;
 
 
-	if (check_fs_open(argv[0]))
+	if (common_extent_args_process(argc, argv, 1, 2, "print_all",
+				       usage, 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;
@@ -1072,8 +1764,10 @@ void do_print_all(int argc, char **argv)
 			op = EXT2_EXTENT_PREV_LEAF;
 			first_op = EXT2_EXTENT_LAST_LEAF;
 			end_err = EXT2_ET_EXTENT_NO_PREV;
-		} else
-			  goto print_usage;
+		} else {
+			fprintf(stderr, "Usage: %s %s\n", argv[0], usage);
+			return;
+		}
 	}
 
 	retval = ext2fs_extent_get(current_handle, first_op, &extent);
@@ -1102,14 +1796,9 @@ void do_info(int argc, char **argv)
 	struct ext2_extent_info	info;
 	errcode_t		retval;
 
-	if (check_fs_open(argv[0]))
+	if (common_extent_args_process(argc, argv, 1, 1, "info", "", 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);
@@ -1140,27 +1829,24 @@ void do_goto_block(int argc, char **argv)
 	errcode_t		retval;
 	int			op = EXT2_EXTENT_NEXT_LEAF;
 	blk_t			blk;
+	int			level = 0;
 
-	if (check_fs_open(argv[0]))
+	if (common_extent_args_process(argc, argv, 2, 3, "goto_block",
+				       "block [level]", 0))
 		return;
 
-	if (!current_handle) {
-		com_err(argv[0], 0, "Extent handle not open");
+	if (strtoblk(argv[0], argv[1], &blk))
 		return;
-	}
 
-	if (argc != 2) {
-		fprintf(stderr, "%s block\n", argv[0]);
-		return;
-	}
+	if (argc == 3)
+		if (strtoblk(argv[0], argv[2], &level))
+			return;
 
-	if (strtoblk(argv[0], argv[1], &blk))
-		return;
+	retval = extent_goto(current_handle, level, (blk64_t) blk);
 
-	retval = ext2fs_extent_goto(current_handle, (blk64_t) blk);
 	if (retval) {
-		com_err(argv[0], retval, "while trying to go to block %lu",
-			blk);
+		com_err(argv[0], retval, "while trying to go to block %lu, level %d",
+			blk, level);
 		return;
 	}