Changeset 260c052 in mainline for uspace/lib/ext2/libext2_filesystem.c

Timestamp:

2011-06-02T08:01:34Z (14 years ago)

Author:

Martin Sucha <sucha14@…>

Branches:

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

Children:

5bd1ffb

Parents:

9bd5746

Message:

coding style

File:

• uspace/lib/ext2/libext2_filesystem.c (modified) (16 diffs)

uspace/lib/ext2/libext2_filesystem.c

@@ -117 +117 @@
 int ext2_filesystem_check_flags(ext2_filesystem_t *fs, bool *o_read_only)
 {
-        // feature flags are present in rev 1 and later
+        /* feature flags are present in rev 1 and later */
         if (ext2_superblock_get_rev_major(fs->superblock) == 0) {
                 *o_read_only = false;
-                return 0;
+                return EOK;
         }
         
@@ -129 +129 @@
         read_only = ext2_superblock_get_features_read_only(fs->superblock);
         
-        // unset any supported features
+        /* check whether we support all features
+         * first unset any supported feature flags
+         * and see whether any unspported feature remains */
         incompatible &= ~EXT2_SUPPORTED_INCOMPATIBLE_FEATURES;
         read_only &= ~EXT2_SUPPORTED_READ_ONLY_FEATURES;
@@ -171 +173 @@
             / EXT2_BLOCK_GROUP_DESCRIPTOR_SIZE;
         
-        // Block group descriptor table starts at the next block after superblock
+        /* Block group descriptor table starts at the next block after superblock */
         block_id = ext2_superblock_get_first_block(fs->superblock) + 1;
         
-        // Find the block containing the descriptor we are looking for
+        /* Find the block containing the descriptor we are looking for */
         block_id += bgid / descriptors_per_block;
         offset = (bgid % descriptors_per_block) * EXT2_BLOCK_GROUP_DESCRIPTOR_SIZE;
@@ -240 +242 @@
         inodes_per_group = ext2_superblock_get_inodes_per_group(fs->superblock);
         
-        // inode numbers are 1-based
+        /* inode numbers are 1-based, but it is simpler to work with 0-based
+         * when computing indices
+         */
         index -= 1;
         block_group = index / inodes_per_group;
@@ -269 +273 @@
         
         newref->inode = newref->block->data + offset_in_block;
-        newref->index = index+1; // we decremented index above
+        /* we decremented index above, but need to store the original value
+         * in the reference
+         */
+        newref->index = index+1;
         
         *ref = newref;
@@ -315 +322 @@
         block_t *block;
         
+        /* Handle simple case when we are dealing with direct reference */ 
         if (iblock < EXT2_INODE_DIRECT_BLOCKS) {
                 current_block = ext2_inode_get_direct_block(inode, (uint32_t)iblock);
@@ -321 +329 @@
         }
         
-        // Compute limits for indirect block levels
-        // TODO: compute this once when loading filesystem and store in ext2_filesystem_t
+        /* Compute limits for indirect block levels
+         * TODO: compute this once when loading filesystem and store in ext2_filesystem_t
+         */
         block_ids_per_block = ext2_superblock_get_block_size(fs->superblock) / sizeof(uint32_t);
         limits[0] = EXT2_INODE_DIRECT_BLOCKS;
@@ -332 +341 @@
         }
         
-        // Determine the indirection level needed to get the desired block
+        /* Determine the indirection level needed to get the desired block */
         level = -1;
         for (i = 1; i < 4; i++) {
@@ -345 +354 @@
         }
         
+        /* Compute offsets for the topmost level */
         block_offset_in_level = iblock - limits[level-1];
         current_block = ext2_inode_get_indirect_block(inode, level-1);
         offset_in_block = block_offset_in_level / blocks_per_level[level-1];
         
+        /* Navigate through other levels, until we find the block number
+         * or find null reference meaning we are dealing with sparse file
+         */
         while (level > 0) {
                 rc = block_get(&block, fs->device, current_block, 0);
@@ -364 +377 @@
                 
                 if (current_block == 0) {
+                        /* This is a sparse file */
                         *fblock = 0;
                         return EOK;
@@ -370 +384 @@
                 level -= 1;
                 
+                /* If we are on the last level, break here as
+                 * there is no next level to visit
+                 */
                 if (level == 0) {
                         break;
                 }
                 
+                /* Visit the next level */
                 block_offset_in_level %= blocks_per_level[level];
                 offset_in_block = block_offset_in_level / blocks_per_level[level-1];
@@ -385 +403 @@
 /**
  * Allocate a given number of blocks and store their ids in blocks
+ * 
+ * @todo TODO: This function is not finished and really has never been
+ *             used (and tested) yet
  * 
  * @param fs pointer to filesystem
@@ -420 +441 @@
         idx = 0;
         
-        // Read the block group descriptor
+        /* Read the block group descriptor */
         rc = ext2_filesystem_get_block_group_ref(fs, block_group, &bg);
         if (rc != EOK) {
@@ -444 +465 @@
                 }
                 
-                // We found a block group with free block, let's look at the block bitmap
+                /* We found a block group with free block, let's look at the block bitmap */
                 bb_block = ext2_block_group_get_block_bitmap_block(bg->block_group);
                 
@@ -452 +473 @@
                 }
                 
-                // Use all blocks from this block group
+                /* Use all blocks from this block group */
                 for (bb_idx = 0; bb_idx < block_size && idx < count; bb_idx++) {
                         uint8_t *data = (uint8_t *) block->data;
@@ -458 +479 @@
                                 continue;
                         }
-                        // find an empty bit
+                        /* find an empty bit */
                         uint8_t mask;
                         for (mask = 1, bb_bit = 0;