ANDROID: Incremental fs: Fix initialization, use of bitfields

Test: incfs_test passes
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Bug: 133435829
Change-Id: I824286b77f665d2409c5e88930057a97da82ce82

fs/incfs/data_mgmt.c

@@ -85,11 +85,11 @@ static void data_file_segment_destroy(struct data_file_segment *segment)
 
 struct data_file *incfs_open_data_file(struct mount_info *mi, struct file *bf)
 {
-	struct data_file *df = NULL;
-	struct backing_file_context *bfc = NULL;
+	struct data_file *df;
+	struct backing_file_context *bfc;
 	int md_records;
 	u64 size;
-	int error = 0;
+	int error;
 	int i;
 
 	if (!bf || !mi)
@@ -160,7 +160,7 @@ int make_inode_ready_for_data_ops(struct mount_info *mi,
 				struct file *backing_file)
 {
 	struct inode_info *node = get_incfs_node(inode);
-	struct data_file *df = NULL;
+	struct data_file *df;
 	int err = 0;
 
 	inode_lock(inode);
@@ -181,7 +181,7 @@ int make_inode_ready_for_data_ops(struct mount_info *mi,
 
 struct dir_file *incfs_open_dir_file(struct mount_info *mi, struct file *bf)
 {
-	struct dir_file *dir = NULL;
+	struct dir_file *dir;
 
 	if (!S_ISDIR(bf->f_inode->i_mode))
 		return ERR_PTR(-EBADF);
@@ -222,11 +222,12 @@ static void log_block_read(struct mount_info *mi, incfs_uuid_t *id,
 	s64 now_us = ktime_to_us(ktime_get());
 	struct read_log_record record = {
 		.file_id = *id,
-		.block_index = block_index,
-		.timed_out = timed_out,
 		.timestamp_us = now_us
 	};
 
+	set_block_index(&record, block_index);
+	set_timed_out(&record, timed_out);
+
 	if (log->rl_size == 0)
 		return;
 
@@ -1062,7 +1063,7 @@ static void fill_pending_read_from_log_record(
 	struct read_log_state *state, u64 log_size)
 {
 	dest->file_id = src->file_id;
-	dest->block_index = src->block_index;
+	dest->block_index = get_block_index(src);
 	dest->serial_number =
 		state->current_pass_no * log_size + state->next_index;
 	dest->timestamp_us = src->timestamp_us;

fs/incfs/data_mgmt.h

@@ -21,15 +21,41 @@
 #define SEGMENTS_PER_FILE 3
 
 struct read_log_record {
-	u32 block_index : 31;
-
-	u32 timed_out : 1;
+	u32 bitfield;
 
 	u64 timestamp_us;
 
 	incfs_uuid_t file_id;
 } __packed;
 
+#define RLR_BLOCK_INDEX_MASK 0x7fff
+#define RLR_TIMED_OUT_MASK 0x8000
+
+static inline u32 get_block_index(const struct read_log_record *rlr)
+{
+	return rlr->bitfield & RLR_BLOCK_INDEX_MASK;
+}
+
+static inline void set_block_index(struct read_log_record *rlr,
+				  u32 block_index)
+{
+	rlr->bitfield = (rlr->bitfield & ~RLR_BLOCK_INDEX_MASK)
+			| (block_index & RLR_BLOCK_INDEX_MASK);
+}
+
+static inline bool get_timed_out(const struct read_log_record *rlr)
+{
+	return (rlr->bitfield & RLR_TIMED_OUT_MASK) == RLR_TIMED_OUT_MASK;
+}
+
+static inline void set_timed_out(struct read_log_record *rlr, bool timed_out)
+{
+	if (timed_out)
+		rlr->bitfield |= RLR_TIMED_OUT_MASK;
+	else
+		rlr->bitfield &= ~RLR_TIMED_OUT_MASK;
+}
+
 struct read_log_state {
 	/* Next slot in rl_ring_buf to write to. */
 	u32 next_index;
@@ -271,7 +297,7 @@ static inline struct inode_info *get_incfs_node(struct inode *inode)
 
 static inline struct data_file *get_incfs_data_file(struct file *f)
 {
-	struct inode_info *node = NULL;
+	struct inode_info *node;
 
 	if (!f)
 		return NULL;

include/uapi/linux/incrementalfs.h

@@ -107,10 +107,13 @@ struct incfs_new_data_block {
 	/* Values from enum incfs_block_flags */
 	__u8 flags;
 
+	/* Reserved - must be 0 */
 	__u16 reserved1;
 
+	/* Reserved - must be 0 */
 	__u32 reserved2;
 
+	/* Reserved - must be 0 */
 	__aligned_u64 reserved3;
 };
 
@@ -140,6 +143,7 @@ struct incfs_file_signature_info {
 	/* Size of additional data. */
 	__u32 additional_data_size;
 
+	/* Reserved - must be 0 */
 	__u32 reserved1;
 
 	/*
@@ -153,6 +157,7 @@ struct incfs_file_signature_info {
 	/* Size of pkcs7 signature DER blob */
 	__u32 signature_size;
 
+	/* Reserved - must be 0 */
 	__u32 reserved2;
 
 	/* Value from incfs_hash_tree_algorithm */
@@ -176,8 +181,10 @@ struct incfs_new_file_args {
 	 */
 	__u16 mode;
 
+	/* Reserved - must be 0 */
 	__u16 reserved1;
 
+	/* Reserved - must be 0 */
 	__u32 reserved2;
 
 	/*
@@ -210,13 +217,16 @@ struct incfs_new_file_args {
 	 */
 	__u32 file_attr_len;
 
+	/* Reserved - must be 0 */
 	__u32 reserved4;
 
 	/* struct incfs_file_signature_info *signature_info; */
 	__aligned_u64 signature_info;
 
+	/* Reserved - must be 0 */
 	__aligned_u64 reserved5;
 
+	/* Reserved - must be 0 */
 	__aligned_u64 reserved6;
 };