+/*
+ * returns 1 if current index have to be freed (even partial)
+ */
+#ifndef __REACTOS__
+static int inline
+#else
+inline int
+#endif
+ext4_ext_more_to_rm(struct ext4_ext_path *path)
+{
+ BUG_ON(path->p_idx == NULL);
+
+ if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
+ return 0;
+
+ /*
+ * if truncate on deeper level happened it it wasn't partial
+ * so we have to consider current index for truncation
+ */
+ if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
+ return 0;
+ return 1;
+}
+
+int ext4_ext_remove_space(void *icb, struct inode *inode, unsigned long start)
+{
+ struct super_block *sb = inode->i_sb;
+ int depth = ext_depth(inode);
+ struct ext4_ext_path *path;
+ handle_t *handle = NULL;
+ int i = 0, err = 0;
+
+ /* probably first extent we're gonna free will be last in block */
+ /*handle = ext4_journal_start(inode, depth + 1);*/
+ /*if (IS_ERR(icb, handle))*/
+ /*return PTR_ERR(icb, handle);*/
+
+ /*
+ * we start scanning from right side freeing all the blocks
+ * after i_size and walking into the deep
+ */
+ path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL);
+ if (path == NULL) {
+ ext4_journal_stop(icb, handle);
+ return -ENOMEM;
+ }
+ memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1));
+ path[0].p_hdr = ext_inode_hdr(inode);
+ if (ext4_ext_check_inode(inode)) {
+ err = -EIO;
+ goto out;
+ }
+ path[0].p_depth = depth;
+
+ while (i >= 0 && err == 0) {
+ if (i == depth) {
+ /* this is leaf block */
+ err = ext4_ext_rm_leaf(icb, handle, inode, path, start);
+ /* root level have p_bh == NULL, extents_brelse() eats this */
+ extents_brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ continue;
+ }
+
+ /* this is index block */
+ if (!path[i].p_hdr) {
+ path[i].p_hdr = ext_block_hdr(path[i].p_bh);
+ }
+
+ if (!path[i].p_idx) {
+ /* this level hasn't touched yet */
+ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
+ } else {
+ /* we've already was here, see at next index */
+ path[i].p_idx--;
+ }
+
+ if (ext4_ext_more_to_rm(path + i)) {
+ struct buffer_head *bh;
+ /* go to the next level */
+ memset(path + i + 1, 0, sizeof(*path));
+ bh = read_extent_tree_block(inode, ext4_idx_pblock(path[i].p_idx), path[0].p_depth - (i + 1), 0);
+ if (IS_ERR(bh)) {
+ /* should we reset i_size? */
+ err = -EIO;
+ break;
+ }
+ path[i+1].p_bh = bh;
+
+ /* put actual number of indexes to know is this
+ * number got changed at the next iteration */
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
+ i++;
+ } else {
+ /* we finish processing this index, go up */
+ if (path[i].p_hdr->eh_entries == 0 && i > 0) {
+ /* index is empty, remove it
+ * handle must be already prepared by the
+ * truncatei_leaf() */
+ err = ext4_ext_rm_idx(icb, handle, inode, path + i);
+ }
+ /* root level have p_bh == NULL, extents_brelse() eats this */
+ extents_brelse(path[i].p_bh);
+ path[i].p_bh = NULL;
+ i--;
+ }
+ }
+
+ /* TODO: flexible tree reduction should be here */
+ if (path->p_hdr->eh_entries == 0) {
+ /*
+ * truncate to zero freed all the tree
+ * so, we need to correct eh_depth
+ */
+ err = ext4_ext_get_access(icb, handle, inode, path);
+ if (err == 0) {
+ ext_inode_hdr(inode)->eh_depth = 0;
+ ext_inode_hdr(inode)->eh_max =
+ cpu_to_le16(ext4_ext_space_root(inode, 0));
+ err = ext4_ext_dirty(icb, handle, inode, path);
+ }
+ }
+out:
+ if (path) {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+ ext4_journal_stop(icb, handle);
+
+ return err;
+}
+
projects / reactos.git / commitdiff