Changeset aab85d90 in mainline for uspace/lib/ext4/src/ialloc.c

Timestamp:

2018-08-27T14:17:14Z (7 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

c606e33, e43d658

Parents:

8867cf6

git-author:

Jiri Svoboda <jiri@…> (2018-08-26 17:15:23)

git-committer:

Jiri Svoboda <jiri@…> (2018-08-27 14:17:14)

Message:

Basic Ext4 filesystem creation (can only create Ext2-old, 1K blocks).

File:

• uspace/lib/ext4/src/ialloc.c (modified) (2 diffs)

uspace/lib/ext4/src/ialloc.c

@@ -1 +1 @@
 /*
+ * Copyright (c) 2018 Jiri Svoboda
  * Copyright (c) 2012 Frantisek Princ
  * All rights reserved.
@@ -311 +312 @@
 }
 
+/** Allocate a specific I-node.
+ *
+ * @param fs     Filesystem to allocate i-node on
+ * @param inode  I-node to allocate
+ * @param is_dir Flag if allocated i-node will be file or directory
+ *
+ * @return Error code
+ *
+ */
+errno_t ext4_ialloc_alloc_this_inode(ext4_filesystem_t *fs, uint32_t inode,
+    bool is_dir)
+{
+        ext4_superblock_t *sb = fs->superblock;
+
+        uint32_t bgid = ext4_ialloc_get_bgid_of_inode(sb, inode);
+        uint32_t sb_free_inodes = ext4_superblock_get_free_inodes_count(sb);
+
+        /* Load block group */
+        ext4_block_group_ref_t *bg_ref;
+        errno_t rc = ext4_filesystem_get_block_group_ref(fs, bgid, &bg_ref);
+        if (rc != EOK)
+                return rc;
+
+        ext4_block_group_t *bg = bg_ref->block_group;
+
+        /* Read necessary values for algorithm */
+        uint32_t free_inodes = ext4_block_group_get_free_inodes_count(bg, sb);
+        uint32_t used_dirs = ext4_block_group_get_used_dirs_count(bg, sb);
+
+        /* Load block with bitmap */
+        uint32_t bitmap_block_addr = ext4_block_group_get_inode_bitmap(
+            bg_ref->block_group, sb);
+
+        block_t *bitmap_block;
+        rc = block_get(&bitmap_block, fs->device, bitmap_block_addr,
+            BLOCK_FLAGS_NONE);
+        if (rc != EOK) {
+                ext4_filesystem_put_block_group_ref(bg_ref);
+                return rc;
+        }
+
+        /* Allocate i-node in the bitmap */
+        uint32_t index_in_group = ext4_ialloc_inode2index_in_group(sb, inode);
+        ext4_bitmap_set_bit(bitmap_block->data, index_in_group);
+
+        /* Save the bitmap */
+        bitmap_block->dirty = true;
+
+        rc = block_put(bitmap_block);
+        if (rc != EOK) {
+                ext4_filesystem_put_block_group_ref(bg_ref);
+                return rc;
+        }
+
+        /* Modify filesystem counters */
+        free_inodes--;
+        ext4_block_group_set_free_inodes_count(bg, sb, free_inodes);
+
+        /* Increment used directories counter */
+        if (is_dir) {
+                used_dirs++;
+                ext4_block_group_set_used_dirs_count(bg, sb, used_dirs);
+        }
+
+        /* Decrease unused inodes count */
+        if (ext4_block_group_has_flag(bg,
+            EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
+                uint32_t unused =
+                    ext4_block_group_get_itable_unused(bg, sb);
+
+                uint32_t inodes_in_group =
+                    ext4_superblock_get_inodes_in_group(sb, bgid);
+
+                uint32_t free = inodes_in_group - unused;
+
+                if (index_in_group >= free) {
+                        unused = inodes_in_group - (index_in_group + 1);
+                        ext4_block_group_set_itable_unused(bg, sb, unused);
+                }
+        }
+
+        /* Save modified block group */
+        bg_ref->dirty = true;
+
+        rc = ext4_filesystem_put_block_group_ref(bg_ref);
+        if (rc != EOK)
+                return rc;
+
+        /* Update superblock */
+        sb_free_inodes--;
+        ext4_superblock_set_free_inodes_count(sb, sb_free_inodes);
+
+        return EOK;
+}
+
 /**
  * @}