Changeset e2f20b9e in mainline

Timestamp:

2018-12-13T13:29:38Z (6 years ago)

Author:

Maurizio Lombardi <mlombard@…>

Branches:

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

Children:

6ea5e7a

Parents:

91fcbabc

Message:

libext4: fixes to flex support in ext4_balloc_get_first_data_block_in_group()

The "first data block in group" was not calculated correctly.
As a consequence, the ext4 filesystem was not able to fully utilize
the available disk space

Location:

uspace/lib/ext4

Files:

• include/ext4/superblock.h (modified) (1 diff)
• src/balloc.c (modified) (1 diff)
• src/superblock.c (modified) (1 diff)

uspace/lib/ext4/include/ext4/superblock.h

@@ -147 +147 @@
 extern void ext4_superblock_set_reserved_gdt_blocks(ext4_superblock_t *sb,
     uint32_t n);
+extern uint32_t ext4_superblock_get_flex_group_size(ext4_superblock_t *sb);
 
 /* More complex superblock functions */

uspace/lib/ext4/src/balloc.c

@@ -261 +261 @@
                  * is always after the inode table.
                  */
+                return itable + itable_sz;
+        }
+
+        uint32_t flex_group_size = ext4_superblock_get_flex_group_size(sb);
+        if ((bg_ref->index % flex_group_size) == 0) {
+                /* This is the base group */
+                uint32_t i;
+
                 r = itable + itable_sz;
-                return ext4_filesystem_blockaddr2_index_in_group(sb, r);
-        }
-
-        uint64_t bbmap = ext4_block_group_get_block_bitmap(bg_ref->block_group,
-            sb);
-        uint64_t ibmap = ext4_block_group_get_inode_bitmap(bg_ref->block_group,
-            sb);
-
-        r = ext4_filesystem_index_in_group2blockaddr(sb, 0, bg_ref->index);
-        r += ext4_filesystem_bg_get_backup_blocks(bg_ref);
-
-        if (ext4_filesystem_blockaddr2group(sb, bbmap) != bg_ref->index)
-                bbmap = -1; /* Invalid */
-
-        if (ext4_filesystem_blockaddr2group(sb, ibmap) != bg_ref->index)
-                ibmap = -1;
-
-        while (true) {
-                if (r == bbmap || r == ibmap)
-                        r++;
-                else if (r >= itable && r < (itable + itable_sz))
-                        r = itable + itable_sz;
-                else
-                        break;
-        }
-
-        return r;
+
+                uint32_t total_groups = ext4_superblock_get_block_group_count(sb);
+                for (i = bg_ref->index + 1;
+                    i < min(total_groups, bg_ref->index + flex_group_size); ++i) {
+                        r += ext4_filesystem_bg_get_itable_size(sb, i);
+                }
+
+                return r;
+        }
+
+        uint64_t base_addr = ext4_filesystem_index_in_group2blockaddr(sb, 0,
+            bg_ref->index);
+        uint32_t reserved = ext4_filesystem_bg_get_backup_blocks(bg_ref);
+
+        return base_addr + reserved;
 }
 

uspace/lib/ext4/src/superblock.c

@@ -1394 +1394 @@
 {
         sb->reserved_gdt_blocks = host2uint32_t_le(n);
+}
+
+/** Get the size of the flex groups
+ *
+ * @param sb    Pointer to the superblock
+ *
+ * @return      Size of the flex groups
+ */
+uint32_t ext4_superblock_get_flex_group_size(ext4_superblock_t *sb)
+{
+        return 2 << sb->log_groups_per_flex;
 }