ref: 2433226aec14ba1e81da887c7e2e9ee1a592fc2f
parent: ad1f9bd09fc8293514646eed78f5a0e10ec9c742
author: ngkaho1234 <[email protected]>
date: Fri Oct 23 12:30:06 EDT 2015
METADATA_CSUM: ext4_extent.c added.
--- a/lwext4/ext4_extent.c
+++ b/lwext4/ext4_extent.c
@@ -124,6 +124,48 @@
*extent = l - 1;
}
+static uint32_t ext4_ext_block_csum(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_header *eh)
+{+ uint32_t checksum = 0;
+ struct ext4_sblock *sb = &inode_ref->fs->sb;
+
+ if (ext4_sb_has_feature_read_only(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {+ uint32_t ino_index = to_le32(inode_ref->index);
+ uint32_t ino_gen =
+ to_le32(ext4_inode_get_generation(inode_ref->inode));
+ /* First calculate crc32 checksum against fs uuid */
+ checksum = ext4_crc32c(~0, sb->uuid, sizeof(sb->uuid));
+ /* Then calculate crc32 checksum against inode number
+ * and inode generation */
+ checksum = ext4_crc32c(checksum, &ino_index,
+ sizeof(ino_index));
+ checksum = ext4_crc32c(checksum, &ino_gen,
+ sizeof(ino_gen));
+ /* Finally calculate crc32 checksum against
+ * the entire extent block up to the checksum field */
+ checksum = ext4_crc32c(checksum, eh,
+ EXT4_EXTENT_TAIL_OFFSET(eh));
+ }
+ return checksum;
+}
+
+/*
+ * BIG FAT NOTES:
+ * Currently we do not verify the checksum of extent
+ * (only the case in ext4_extent.c)
+ */
+
+static void ext4_extent_block_csum_set(struct ext4_inode_ref *inode_ref,
+ struct ext4_extent_header *eh)
+{+ struct ext4_extent_tail *tail;
+
+ tail = find_ext4_extent_tail(eh);
+ tail->et_checksum = ext4_ext_block_csum(inode_ref, eh);
+}
+
/**@brief Get physical block in the extent tree by logical block number.
* There is no need to save path in the tree during this algorithm.
* @param inode_ref I-node to load block from
@@ -423,6 +465,7 @@
}
ext4_extent_header_set_entries_count(path_ptr->header, entries);
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
path_ptr->block.dirty = true;
/* If leaf node is empty, parent entry must be modified */
@@ -464,6 +507,7 @@
}
ext4_extent_header_set_entries_count(path_ptr->header, entries);
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
path_ptr->block.dirty = true;
/* Free the node if it is empty */
@@ -591,6 +635,7 @@
path_ptr->depth);
ext4_extent_header_set_generation(path_ptr->header, 0);
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
path_ptr->block.dirty = true;
/* Jump to the preceding item */
@@ -616,6 +661,7 @@
ext4_extent_header_set_entries_count(path_ptr->header,
entries + 1);
+ ext4_extent_block_csum_set(inode_ref, path_ptr->header);
path_ptr->block.dirty = true;
/* No more splitting needed */
@@ -698,6 +744,7 @@
ext4_extent_header_set_max_entries_count(old_root->header,
limit);
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(old_root->block));
old_root->block.dirty = true;
/* Re-initialize new root metadata */
@@ -714,6 +761,8 @@
ext4_extent_index_set_first_block(new_root->index, 0);
ext4_extent_index_set_leaf(new_root->index, new_fblock);
+ /* Since new_root belongs to on-disk inode,
+ * we don't do checksum here */
new_root->block.dirty = true;
} else { if (path->depth) {@@ -729,6 +778,8 @@
}
ext4_extent_header_set_entries_count(path->header, entries + 1);
+ /* Since new_root belongs to on-disk inode,
+ * we don't do checksum here */
path->block.dirty = true;
}
@@ -808,6 +859,7 @@
inode_ref->dirty = true;
}
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(path_ptr->block));
path_ptr->block.dirty = true;
goto finish;
@@ -849,6 +901,7 @@
inode_ref->dirty = true;
}
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(path_ptr->block));
path_ptr->block.dirty = true;
goto finish;
@@ -889,6 +942,7 @@
inode_ref->dirty = true;
}
+ ext4_extent_block_csum_set(inode_ref, ext_block_hdr(path_ptr->block));
path_ptr->block.dirty = true;
finish: