Changeset 052e82d in mainline for uspace/lib/ext4/libext4_filesystem.c

Timestamp:

2011-11-07T11:50:31Z (14 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

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

Children:

12b4a7f

Parents:

5664cf64

Message:

partially functional truncate operation

File:

• uspace/lib/ext4/libext4_filesystem.c (modified) (3 diffs)

uspace/lib/ext4/libext4_filesystem.c

@@ -251 +251 @@
          */
         newref->index = index+1;
+        newref->dirty = false;
 
         *ref = newref;
@@ -261 +262 @@
 {
         int rc;
+
+        if (ref->dirty) {
+                ref->block->dirty = true;
+        }
 
         rc = block_put(ref->block);
@@ -355 +360 @@
 
 
-int ext4_filesystem_release_inode_block(ext4_filesystem_t *fs, ext4_inode_t *inode, uint32_t iblock)
+int ext4_filesystem_release_inode_block(ext4_filesystem_t *fs,
+                ext4_inode_ref_t *inode_ref, uint32_t iblock)
 {
         int rc;
         uint32_t fblock;
-
-        // TODO handle with extents
-
-        rc = ext4_filesystem_get_inode_data_block_index(fs, inode, iblock, &fblock);
-        if (rc != EOK) {
-                // TODO error
-                return rc;
-        }
-
-        // Sparse file
-        if (fblock == 0) {
-
-                //
-                return EOK;
-        }
-
-
-        // TODO vyhledat policko s ukazatelem a nastavit nulu
-
-
-        // TODO uvolnit blok v bitmape
-
-        // TODO return
-
-
-        return EOK;
+        int i;
+        int level;
+        aoff64_t block_offset_in_level;
+        uint32_t current_block;
+        uint32_t offset_in_block;
+        block_t *block;
+        ext4_inode_t *inode = inode_ref->inode;
+
+        /* TODO handle extents */
+
+        /* Handle simple case when we are dealing with direct reference */
+        if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
+                EXT4FS_DBG("direct block");
+                fblock = ext4_inode_get_direct_block(inode, (uint32_t)iblock);
+                // Sparse file
+                if (fblock == 0) {
+                        return EOK;
+                }
+
+                ext4_inode_set_direct_block(inode, iblock, 0);
+                return ext4_bitmap_free_block(fs, fblock);
+        } else {
+
+                /* Determine the indirection level needed to get the desired block */
+                level = -1;
+                for (i = 1; i < 4; i++) {
+                        if (iblock < fs->inode_block_limits[i]) {
+                                level = i;
+                                break;
+                        }
+                }
+
+                if (level == -1) {
+                        return EIO;
+                }
+
+                /* Compute offsets for the topmost level */
+                block_offset_in_level = iblock - fs->inode_block_limits[level-1];
+                current_block = ext4_inode_get_indirect_block(inode, level-1);
+                offset_in_block = block_offset_in_level / fs->inode_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);
+                        if (rc != EOK) {
+                                return rc;
+                        }
+
+                        current_block = uint32_t_le2host(((uint32_t*)block->data)[offset_in_block]);
+
+                        // Set zero
+                        if (level == 1) {
+                                ((uint32_t*)block->data)[offset_in_block] = host2uint32_t_le(0);
+                                block->dirty = true;
+                        }
+
+                        rc = block_put(block);
+                        if (rc != EOK) {
+                                return rc;
+                        }
+
+                        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 %= fs->inode_blocks_per_level[level];
+                        offset_in_block = block_offset_in_level / fs->inode_blocks_per_level[level-1];
+                }
+
+                fblock = current_block;
+
+                if (fblock == 0) {
+                        return EOK;
+                }
+        }
+
+        return ext4_bitmap_free_block(fs, fblock);
+
 }