Add layer 3-log

src/error.rs

@@ -5,18 +5,24 @@ pub enum Errno {
     TxAborted,
     /// Not found.
     NotFound,
+    /// Invalid arguments.
     InvalidArgs,
-    NoMemory,
-    IoError,
-    NotEnoughSpace,
+    /// Out of memory.
+    OutOfMemory,
+    /// Out of disk space.
+    OutOfDisk,
+    /// IO error.
+    IoFailed,
+    /// Permission denied.
+    PermissionDenied,
     /// OS-specific unknown error.
     OsSpecUnknown,
     /// Encryption operation failed.
-    EncryptFault,
+    EncryptFailed,
     /// Decryption operation failed.
-    DecryptFault,
+    DecryptFailed,
     /// Not aligned to `BLOCK_SIZE`.
-    NonBlockAlignedSizeError,
+    NotBlockSizeAligned,
 }
 
 /// error used in this crate

src/layers/0-bio/block_buf.rs

@@ -31,6 +31,12 @@ pub struct Buf(Pages);
 impl Buf {
     /// Allocate specific number of blocks as memory buffer.
     pub fn alloc(num_blocks: usize) -> Result<Self> {
+        if num_blocks == 0 {
+            return_errno_with_msg!(
+                InvalidArgs,
+                "num_blocks must be greater than 0 for allocation"
+            )
+        }
         let pages = Pages::alloc(num_blocks)?;
         Ok(Self(pages))
     }
@@ -89,7 +95,7 @@ impl<'a> TryFrom<&'a [u8]> for BufRef<'a> {
 
     fn try_from(buf: &'a [u8]) -> Result<Self> {
         if buf.len() % BLOCK_SIZE != 0 {
-            return_errno!(Errno::NonBlockAlignedSizeError);
+            return_errno!(Errno::NotBlockSizeAligned);
         }
         let new_self = Self(buf);
         Ok(new_self)
@@ -137,7 +143,7 @@ impl<'a> TryFrom<&'a mut [u8]> for BufMut<'a> {
 
     fn try_from(buf: &'a mut [u8]) -> Result<Self> {
         if buf.len() % BLOCK_SIZE != 0 {
-            return_errno!(Errno::NonBlockAlignedSizeError);
+            return_errno!(Errno::NotBlockSizeAligned);
         }
         let new_self = Self(buf);
         Ok(new_self)

src/layers/0-bio/block_set.rs

@@ -125,6 +125,7 @@ impl_blockset_for!(Arc<T>, "(**self)", |this: &Arc<T>, range| {
 /// A disk that impl `BlockSet`.
 ///
 /// The `region` is the accessible subset.
+#[derive(Clone)]
 pub struct MemDisk {
     disk: Arc<Mutex<Buf>>,
     region: Range<BlockId>,

src/layers/0-bio/mod.rs

@@ -1,3 +1,5 @@
+//! The layer of untrusted block I/O.
+
 use static_assertions::assert_eq_size;
 
 mod block_buf;

src/layers/1-crypto/crypto_blob.rs

@@ -80,7 +80,7 @@ impl<B: BlockSet> CryptoBlob<B> {
     pub fn create(block_set: B, init_data: &[u8]) -> Result<Self> {
         let capacity = block_set.nblocks() * BLOCK_SIZE - Self::HEADER_NBYTES;
         if init_data.len() > capacity {
-            return_errno_with_msg!(NotEnoughSpace, "init_data is too large");
+            return_errno_with_msg!(OutOfDisk, "init_data is too large");
         }
         let nblocks = (Self::HEADER_NBYTES + init_data.len() + BLOCK_SIZE - 1) / BLOCK_SIZE;
         let mut block_buf = Buf::alloc(nblocks)?;
@@ -129,7 +129,7 @@ impl<B: BlockSet> CryptoBlob<B> {
     /// known to an attacker.
     pub fn write(&mut self, buf: &[u8]) -> Result<VersionId> {
         if buf.len() > self.capacity() {
-            return_errno_with_msg!(NotEnoughSpace, "write data is too large");
+            return_errno_with_msg!(OutOfDisk, "write data is too large");
         }
         let nblocks = (Self::HEADER_NBYTES + buf.len() + BLOCK_SIZE - 1) / BLOCK_SIZE;
         let mut block_buf = Buf::alloc(nblocks)?;
@@ -178,10 +178,10 @@ impl<B: BlockSet> CryptoBlob<B> {
             }
         };
         if header.payload_len > self.capacity() {
-            return_errno_with_msg!(NotEnoughSpace, "payload_len is greater than the capacity");
+            return_errno_with_msg!(OutOfDisk, "payload_len is greater than the capacity");
         }
         if header.payload_len > buf.len() {
-            return_errno_with_msg!(NotEnoughSpace, "read_buf is too small");
+            return_errno_with_msg!(OutOfDisk, "read_buf is too small");
         }
         let nblock = (Self::HEADER_NBYTES + header.payload_len + BLOCK_SIZE - 1) / BLOCK_SIZE;
         let mut block_buf = Buf::alloc(nblock)?;

src/layers/1-crypto/crypto_chain.rs

@@ -108,10 +108,7 @@ impl<L: BlockLog> CryptoChain<L> {
 
         let payload_len = footer.len as usize;
         if payload_len > Self::AVAIL_BLOCK_SIZE || payload_len > buf.len() {
-            return_errno_with_msg!(
-                NotEnoughSpace,
-                "wrong payload_len or the read_buf is too small"
-            );
+            return_errno_with_msg!(OutOfDisk, "wrong payload_len or the read_buf is too small");
         }
 
         // Check the footer MAC, to ensure the orderness and consecutiveness of blocks.
@@ -142,7 +139,7 @@ impl<L: BlockLog> CryptoChain<L> {
     /// The confidentiality of the block is guaranteed.
     pub fn append(&mut self, buf: &[u8]) -> Result<()> {
         if buf.len() > Self::AVAIL_BLOCK_SIZE {
-            return_errno_with_msg!(NotEnoughSpace, "append data is too large");
+            return_errno_with_msg!(OutOfDisk, "append data is too large");
         }
         let mut block_buf = Buf::alloc(1)?;
 

src/layers/1-crypto/crypto_log.rs

@@ -885,7 +885,7 @@ impl<L: BlockLog> AppendDataBuf<L> {
 
     pub fn append_data_nodes(&mut self, nodes: Vec<Arc<DataNode>>) -> Result<()> {
         if self.is_full() {
-            return_errno_with_msg!(NoMemory, "cache out of capacity");
+            return_errno_with_msg!(OutOfMemory, "cache out of capacity");
         }
 
         self.node_queue.extend(nodes.into_iter());

src/layers/2-edit/journal.rs

@@ -61,6 +61,8 @@ pub struct EditJournal<
 /// The metadata of an edit journal.
 ///
 /// The metadata is mainly useful when recovering an edit journal after a reboot.
+#[repr(C)]
+#[derive(Clone, Copy, Pod, Debug)]
 pub struct EditJournalMeta {
     /// The number of blocks reserved for storing a snapshot `CryptoBlob`.
     pub snapshot_area_nblocks: usize,
@@ -357,14 +359,14 @@ where
             CryptoBlob::<D>::HEADER_NBYTES + state_max_nbytes + Snapshot::<D>::meta_len();
         let blob_blocks = (blob_bytes + BLOCK_SIZE - 1) / BLOCK_SIZE;
         if 2 * blob_blocks >= disk.nblocks() {
-            return_errno_with_msg!(NotEnoughSpace, "the block_set for journal is too small");
+            return_errno_with_msg!(OutOfDisk, "the block_set for journal is too small");
         };
         let mut buf = Buf::alloc(blob_blocks)?;
 
         // Serialize snapshot (state + metadata).
         let snapshot = Snapshot::create(init_state.clone(), 0);
         let serialized = postcard::to_slice(snapshot.as_ref(), buf.as_mut_slice())
-            .map_err(|_| Error::with_msg(NotEnoughSpace, "serialize snapshot failed"))?;
+            .map_err(|_| Error::with_msg(OutOfDisk, "serialize snapshot failed"))?;
 
         // Persist snapshot to `CryptoBlob`.
         let block_set0 = disk.subset(0..blob_blocks)?;
@@ -398,15 +400,15 @@ where
         let snapshot0_res = match blob0.read(buf.as_mut_slice()) {
             Ok(snapshot_len) => {
                 postcard::from_bytes::<Snapshot<S>>(&buf.as_slice()[..snapshot_len])
-                    .map_err(|_| Error::with_msg(NotEnoughSpace, "deserialize snapshot0 failed"))
+                    .map_err(|_| Error::with_msg(OutOfDisk, "deserialize snapshot0 failed"))
                     .map(|snapshot| Arc::new(snapshot))
             }
             Err(_) => Err(Error::with_msg(NotFound, "failed to read snapshot0")),
         };
         let snapshot1_res = match blob1.read(buf.as_mut_slice()) {
             Ok(snapshot_len) => {
                 postcard::from_bytes::<Snapshot<S>>(&buf.as_slice()[..snapshot_len])
-                    .map_err(|_| Error::with_msg(NotEnoughSpace, "deserialize snapshot1 failed"))
+                    .map_err(|_| Error::with_msg(OutOfDisk, "deserialize snapshot1 failed"))
                     .map(|snapshot| Arc::new(snapshot))
             }
             Err(_) => Err(Error::with_msg(NotFound, "failed to read snapshot1")),
@@ -456,7 +458,7 @@ where
     pub fn persist(&mut self, latest: Arc<Snapshot<S>>) -> Result<()> {
         // Serialize the latest snapshot.
         let buf = postcard::to_slice(latest.as_ref(), self.buf.as_mut_slice())
-            .map_err(|_| Error::with_msg(NotEnoughSpace, "serialize current state failed"))?;
+            .map_err(|_| Error::with_msg(OutOfDisk, "serialize current state failed"))?;
 
         // Persist the latest snapshot to `CryptoBlob`.
         let index = (self.latest_index + 1) % 2; // switch the `latest_index`
@@ -630,7 +632,7 @@ impl<E: Edit<S>, S: Sized> WriteBuf<E, S> {
                         e
                     );
                 }
-                return_errno_with_msg!(NotEnoughSpace, "no space for new Record in WriteBuf");
+                return_errno_with_msg!(OutOfDisk, "no space for new Record in WriteBuf");
             }
         }
     }