Changeset 1c1c736 in mainline for uspace/lib/ext4/libext4_bitmap.c

Timestamp:

2011-11-08T13:05:43Z (13 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

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

Children:

0f09d4ea

Parents:

e31e56a1

Message:

not functional block allocation + write operation skeleton

File:

• uspace/lib/ext4/libext4_bitmap.c (modified) (3 diffs)

uspace/lib/ext4/libext4_bitmap.c

@@ -54 +54 @@
 }
 
+static int ext4_bitmap_find_free_bit_and_set(uint8_t *bitmap, uint32_t *index, uint32_t size)
+{
+        uint8_t *pos = bitmap;
+        int i;
+        uint32_t idx = 0;
+
+        while (pos < bitmap + size) {
+                if ((*pos & 255) != 255) {
+                        // free bit found
+                        break;
+                }
+
+                ++pos;
+                idx += 8;
+        }
+
+        if (pos < bitmap + size) {
+
+                for(i = 0; i < 8; ++i) {
+                        if ((*pos & (1 << i)) == 0) {
+                                // free bit found
+                                *pos |= (1 << i);
+                                *index = idx;
+                                return EOK;
+                        }
+
+                        idx++;
+                }
+        }
+
+        return ENOSPC;
+}
+
 int ext4_bitmap_free_block(ext4_filesystem_t *fs, uint32_t block_index)
 {
@@ -93 +126 @@
         bg_ref->dirty = true;
 
+        // TODO change free blocks count in superblock
+
         rc = ext4_filesystem_put_block_group_ref(bg_ref);
         if (rc != EOK) {
@@ -102 +137 @@
 }
 
+int ext4_bitmap_alloc_block(ext4_filesystem_t *fs, ext4_inode_ref_t *inode_ref, uint32_t *fblock)
+{
+        int rc;
+        uint32_t inodes_per_group, block_group, blocks_per_group;
+        ext4_block_group_ref_t *bg_ref;
+        uint32_t bitmap_block;
+        block_t *block;
+        uint32_t rel_block_idx = 0;
+        uint32_t block_size;
+
+        inodes_per_group = ext4_superblock_get_inodes_per_group(fs->superblock);
+        block_group = inode_ref->index / inodes_per_group;
+
+        block_size = ext4_superblock_get_block_size(fs->superblock);
+
+        rc = ext4_filesystem_get_block_group_ref(fs, block_group, &bg_ref);
+        if (rc != EOK) {
+                return rc;
+        }
+
+        bitmap_block = ext4_block_group_get_block_bitmap(bg_ref->block_group);
+
+        rc = block_get(&block, fs->device, bitmap_block, 0);
+        if (rc != EOK) {
+                ext4_filesystem_put_block_group_ref(bg_ref);
+                return rc;
+        }
+
+        rc = ext4_bitmap_find_free_bit_and_set(block->data, &rel_block_idx, block_size);
+
+        // if ENOSPC - try next block group - try next block groups
+
+
+
+
+        // TODO decrement superblock & block group free blocks count
+
+        // return
+        blocks_per_group = ext4_superblock_get_blocks_per_group(fs->superblock);
+        *fblock = blocks_per_group * block_group + rel_block_idx;
+        return EOK;
+
+}
 
 /**