Changeset 8060341a in mainline

Timestamp:

2012-05-15T13:27:43Z (12 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

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

Children:

15b794d

Parents:

f2eece1

Message:

filesystem code comments

File:

• uspace/lib/ext4/libext4_filesystem.c (modified) (20 diffs)

uspace/lib/ext4/libext4_filesystem.c

@@ -821 +821 @@
 }
 
-/** TODO comment
- *
+/** Set physical block address for the block logical address into the i-node.
+ *
+ * @param inode_ref             i-node to set block address to
+ * @param iblock                logical index of block
+ * @param fblock                physical block address
+ * @return                              error code
  */
 int ext4_filesystem_set_inode_data_block_index(ext4_inode_ref_t *inode_ref,
@@ -831 +835 @@
         ext4_filesystem_t *fs = inode_ref->fs;
 
-        /* Handle inode using extents */
+        // Handle inode using extents
         if (ext4_superblock_has_feature_compatible(fs->superblock, EXT4_FEATURE_INCOMPAT_EXTENTS) &&
                         ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS)) {
@@ -838 +842 @@
         }
 
-        /* Handle simple case when we are dealing with direct reference */
+        // Handle simple case when we are dealing with direct reference
         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
                 ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock, fblock);
@@ -845 +849 @@
         }
 
-        /* Determine the indirection level needed to get the desired block */
+        // Determine the indirection level needed to get the desired block
         int level = -1;
         for (int i = 1; i < 4; i++) {
@@ -860 +864 @@
         uint32_t block_size = ext4_superblock_get_block_size(fs->superblock);
 
-        /* Compute offsets for the topmost level */
+        // Compute offsets for the topmost level
         aoff64_t block_offset_in_level = iblock - fs->inode_block_limits[level-1];
         uint32_t current_block = ext4_inode_get_indirect_block(inode_ref->inode, level-1);
@@ -868 +872 @@
         block_t *block, *new_block;
 
+        // Is needed to allocate indirect block on the i-node level
         if (current_block == 0) {
+
+                // Allocate new indirect block
                 rc = ext4_balloc_alloc_block(inode_ref, &new_block_addr);
                 if (rc != EOK) {
@@ -874 +881 @@
                 }
 
+                // Update i-node
                 ext4_inode_set_indirect_block(inode_ref->inode, level - 1, new_block_addr);
-
                 inode_ref->dirty = true;
 
+                // Load newly allocated block
                 rc = block_get(&new_block, fs->device, new_block_addr, BLOCK_FLAGS_NOREAD);
                 if (rc != EOK) {
@@ -884 +892 @@
                 }
 
+                // Initialize new block
                 memset(new_block->data, 0, block_size);
                 new_block->dirty = true;
 
+                // Put back the allocated block
                 rc = block_put(new_block);
                 if (rc != EOK) {
@@ -908 +918 @@
 
                 if ((level > 1) && (current_block == 0)) {
+
+                        // Allocate new block
                         rc = ext4_balloc_alloc_block(inode_ref, &new_block_addr);
                         if (rc != EOK) {
@@ -914 +926 @@
                         }
 
+                        // Load newly allocated block
                         rc = block_get(&new_block, fs->device, new_block_addr, BLOCK_FLAGS_NOREAD);
                         if (rc != EOK) {
@@ -920 +933 @@
                         }
 
+                        // Initialize allocated block
                         memset(new_block->data, 0, block_size);
                         new_block->dirty = true;
@@ -929 +943 @@
                         }
 
+                        // Write block address to the parent
                         ((uint32_t*)block->data)[offset_in_block] = host2uint32_t_le(new_block_addr);
                         block->dirty = true;
@@ -934 +949 @@
                 }
 
+                // Will be finished, write the fblock address
                 if (level == 1) {
                         ((uint32_t*)block->data)[offset_in_block] = host2uint32_t_le(fblock);
@@ -961 +977 @@
 }
 
-/** TODO comment
- *
+/** Release data block from i-node
+ *
+ * @param inode_ref     i-node to release block from
+ * @param iblock                logical block to be released
+ * @return                              error code
  */
 int ext4_filesystem_release_inode_block(
@@ -973 +992 @@
         ext4_filesystem_t *fs = inode_ref->fs;
 
-        // EXTENTS are handled otherwise
+        // EXTENTS are handled otherwise = there is not support in this function
         assert(! (ext4_superblock_has_feature_incompatible(fs->superblock,
                         EXT4_FEATURE_INCOMPAT_EXTENTS) &&
@@ -980 +999 @@
         ext4_inode_t *inode = inode_ref->inode;
 
-        /* Handle simple case when we are dealing with direct reference */
+        // Handle simple case when we are dealing with direct reference
         if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
                 fblock = ext4_inode_get_direct_block(inode, iblock);
@@ -993 +1012 @@
 
 
-        /* Determine the indirection level needed to get the desired block */
+        // Determine the indirection level needed to get the desired block
         int level = -1;
         for (int i = 1; i < 4; i++) {
@@ -1006 +1025 @@
         }
 
-        /* Compute offsets for the topmost level */
+        // Compute offsets for the topmost level
         aoff64_t block_offset_in_level = iblock - fs->inode_block_limits[level-1];
         uint32_t current_block = ext4_inode_get_indirect_block(inode, level-1);
@@ -1023 +1042 @@
                 current_block = uint32_t_le2host(((uint32_t*)block->data)[offset_in_block]);
 
-                // Set zero
+                // Set zero if physical data block address found
                 if (level == 1) {
                         ((uint32_t*)block->data)[offset_in_block] = host2uint32_t_le(0);
@@ -1053 +1072 @@
                 return EOK;
         }
+
+        // Physical block is not referenced, it can be released
 
         return ext4_balloc_free_block(inode_ref, fblock);