Changeset ee3b6150 in mainline for uspace/lib/ext4/libext4_extent.c

Timestamp:

2012-04-23T16:01:14Z (13 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

bc03679

Parents:

6773ff3

Message:

I-node allocator comments, hash comments, part of the extent comments

File:

• uspace/lib/ext4/libext4_extent.c (modified) (13 diffs)

uspace/lib/ext4/libext4_extent.c

@@ -523 +523 @@
 }
 
-// TODO comments
-
-// Recursive release
+/** Recursively release the whole branch of the extent tree.
+ *
+ * For each entry of the node release the subbranch and finally release
+ * the node. In the leaf node all extents will be released.
+ *
+ * @param inode_ref             i-node where the branch is released
+ * @param index                 index in the non-leaf node to be released
+ *                                              with the whole subtree
+ * @return                              error code
+ */
 static int ext4_extent_release_branch(ext4_inode_ref_t *inode_ref,
                 ext4_extent_index_t *index)
@@ -534 +541 @@
 
         uint32_t fblock = ext4_extent_index_get_leaf(index);
-
-//      EXT4FS_DBG("fblock = \%u", fblock);
 
         rc = block_get(&block, inode_ref->fs->device, fblock, BLOCK_FLAGS_NOREAD);
@@ -547 +552 @@
         if (ext4_extent_header_get_depth(header)) {
 
+                // The node is non-leaf, do recursion
+
                 ext4_extent_index_t *idx = EXT4_EXTENT_FIRST_INDEX(header);
 
+                // Release all subbranches
                 for (uint32_t i = 0; i < ext4_extent_header_get_entries_count(header); ++i, ++idx) {
                         rc = ext4_extent_release_branch(inode_ref, idx);
@@ -557 +565 @@
                 }
         } else {
+
+                // Leaf node reached
                 ext4_extent_t *ext = EXT4_EXTENT_FIRST(header);
+
+                // Release all extents and stop recursion
 
                 for (uint32_t i = 0; i < ext4_extent_header_get_entries_count(header); ++i, ++ext) {
@@ -568 +580 @@
         }
 
+        // Release data block where the node was stored
+
         rc = block_put(block);
         if (rc != EOK) {
@@ -579 +593 @@
 }
 
+/** Release all data blocks starting from specified logical block.
+ *
+ * @param inode_ref             i-node to release blocks from
+ * @param iblock_from   first logical block to release
+ */
 int ext4_extent_release_blocks_from(ext4_inode_ref_t *inode_ref,
                 uint32_t iblock_from)
@@ -609 +628 @@
                         ext4_extent_get_start(path_ptr->extent);
 
+        // Release all blocks
         rc = ext4_balloc_free_blocks(inode_ref, first_fblock, delete_count);
         if (rc != EOK) {
@@ -614 +634 @@
         }
 
+        // Correct counter
         block_count -= delete_count;
         ext4_extent_set_block_count(path_ptr->extent, block_count);
 
+        // Initialize the following loop
         uint16_t entries = ext4_extent_header_get_entries_count(path_ptr->header);
         ext4_extent_t *tmp_ext = path_ptr->extent + 1;
@@ -658 +680 @@
         --path_ptr;
 
-        // release all successors in all levels
-        while(path_ptr >= path) {
+        // release all successors in all tree levels
+        while (path_ptr >= path) {
                 entries = ext4_extent_header_get_entries_count(path_ptr->header);
                 ext4_extent_index_t *index = path_ptr->index + 1;
@@ -665 +687 @@
                                 EXT4_EXTENT_FIRST_INDEX(path_ptr->header) + entries;
 
+                // Correct entry because of changes in the previous iteration
                 if (check_tree) {
                         entries--;
                         ext4_extent_header_set_entries_count(path_ptr->header, entries);
-                }
-
+                } else {
+                        // TODO check this condition
+                        break;
+                }
+
+                // Iterate over all entries and release the whole subtrees
                 while (index < stop) {
                         rc = ext4_extent_release_branch(inode_ref, index);
@@ -682 +709 @@
                 path_ptr->block->dirty = true;
 
+                // Free the node if it is empty
                 if ((entries == 0) && (path_ptr != path)) {
                         rc = ext4_balloc_free_block(inode_ref, path_ptr->block->lba);
@@ -687 +715 @@
                                 goto cleanup;
                         }
+
+                        // Mark parent to be checked
                         check_tree = true;
                 } else {
@@ -711 +741 @@
 }
 
+/** TODO
+ *
+ */
 static int ext4_extent_append_extent(ext4_inode_ref_t *inode_ref,
                 ext4_extent_path_t *path, ext4_extent_path_t **last_path_item,