+/*
+ * 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)