[PATCH 01/18] Squashfs: convert SQUASHFS_COMPRESSED_* to inline functions

[Phillip Lougher <phillip@squashfs.org.uk>]

Convert old fashioned #define macros into inline functions.  This has
the following improvements:

1. Inline functions are typed, which makes the width and sigedness of
   input and outputs explicit, which reduces errors.

2. The inline functions enable more sanity checking to be added in
   later commits.

3. Inline functions are easier to read than #define macros, which
   improves code comprehension.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
---
 fs/squashfs/block.c            | 11 ++++++-----
 fs/squashfs/cache.c            |  1 +
 fs/squashfs/file.c             |  3 ++-
 fs/squashfs/squashfs_fs.h      | 17 -----------------
 fs/squashfs/squashfs_helpers.h | 35 ++++++++++++++++++++++++++++++++++
 5 files changed, 44 insertions(+), 23 deletions(-)
 create mode 100644 fs/squashfs/squashfs_helpers.h

diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 2d5850168026..20c3030b4f96 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -23,6 +23,7 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
+#include "squashfs_helpers.h"
 #include "squashfs.h"
 #include "decompressor.h"
 #include "page_actor.h"
@@ -292,7 +293,7 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length,
 {
 	struct squashfs_sb_info *msblk = sb->s_fs_info;
 	struct bio *bio = NULL;
-	int compressed;
+	bool compressed;
 	int res;
 	int offset;
 
@@ -300,8 +301,8 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length,
 		/*
 		 * Datablock.
 		 */
-		compressed = SQUASHFS_COMPRESSED_BLOCK(length);
-		length = SQUASHFS_COMPRESSED_SIZE_BLOCK(length);
+		compressed = squashfs_compressed_block(length);
+		length = squashfs_compressed_size_block(length);
 		TRACE("Block @ 0x%llx, %scompressed size %d, src size %d\n",
 			index, compressed ? "" : "un", length, output->length);
 	} else {
@@ -341,8 +342,8 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length,
 		bio_uninit(bio);
 		kfree(bio);
 
-		compressed = SQUASHFS_COMPRESSED(length);
-		length = SQUASHFS_COMPRESSED_SIZE(length);
+		compressed = squashfs_compressed(length);
+		length = squashfs_compressed_size(length);
 		index += 2;
 
 		TRACE("Block @ 0x%llx, %scompressed size %d\n", index - 2,
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c
index c1a83bb0e519..7cb16414cd23 100644
--- a/fs/squashfs/cache.c
+++ b/fs/squashfs/cache.c
@@ -42,6 +42,7 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
+#include "squashfs_helpers.h"
 #include "squashfs.h"
 #include "page_actor.h"
 
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index d83594ce91d2..ad6382cd22d3 100644
--- a/fs/squashfs/file.c
+++ b/fs/squashfs/file.c
@@ -39,6 +39,7 @@
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
 #include "squashfs_fs_i.h"
+#include "squashfs_helpers.h"
 #include "squashfs.h"
 #include "page_actor.h"
 
@@ -188,7 +189,7 @@ static long long read_indexes(struct super_block *sb, int n,
 				err = size;
 				goto failure;
 			}
-			block += SQUASHFS_COMPRESSED_SIZE_BLOCK(size);
+			block += squashfs_compressed_size_block(size);
 		}
 		n -= blocks;
 	}
diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h
index a955d9369749..b406e52a83c2 100644
--- a/fs/squashfs/squashfs_fs.h
+++ b/fs/squashfs/squashfs_fs.h
@@ -101,22 +101,6 @@
 #define SQUASHFS_XATTR_VALUE_OOL        256
 #define SQUASHFS_XATTR_PREFIX_MASK      0xff
 
-/* Flag whether block is compressed or uncompressed, bit is set if block is
- * uncompressed */
-#define SQUASHFS_COMPRESSED_BIT		(1 << 15)
-
-#define SQUASHFS_COMPRESSED_SIZE(B)	(((B) & ~SQUASHFS_COMPRESSED_BIT) ? \
-		(B) & ~SQUASHFS_COMPRESSED_BIT :  SQUASHFS_COMPRESSED_BIT)
-
-#define SQUASHFS_COMPRESSED(B)		(!((B) & SQUASHFS_COMPRESSED_BIT))
-
-#define SQUASHFS_COMPRESSED_BIT_BLOCK	(1 << 24)
-
-#define SQUASHFS_COMPRESSED_SIZE_BLOCK(B)	((B) & \
-						~SQUASHFS_COMPRESSED_BIT_BLOCK)
-
-#define SQUASHFS_COMPRESSED_BLOCK(B)	(!((B) & SQUASHFS_COMPRESSED_BIT_BLOCK))
-
 static inline int squashfs_block_size(__le32 raw)
 {
 	u32 size = le32_to_cpu(raw);
@@ -449,5 +433,4 @@ struct squashfs_xattr_id_table {
 	__le32			xattr_ids;
 	__le32			unused;
 };
-
 #endif
diff --git a/fs/squashfs/squashfs_helpers.h b/fs/squashfs/squashfs_helpers.h
new file mode 100644
index 000000000000..94edc7f46ae4
--- /dev/null
+++ b/fs/squashfs/squashfs_helpers.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef SQUASHFS_HELPERS_H
+#define SQUASHFS_HELPERS_H
+/*
+ * Copyright (c) 2026
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ */
+
+/* Flag whether block is compressed or uncompressed, bit is set if block is
+ * uncompressed
+ */
+#define SQUASHFS_COMPRESSED_BIT		(1 << 15)
+
+static inline s16 squashfs_compressed_size(s16 size)
+{
+	return size & ~SQUASHFS_COMPRESSED_BIT;
+}
+
+static inline bool squashfs_compressed(s16 size)
+{
+	return (size & SQUASHFS_COMPRESSED_BIT) == 0;
+}
+
+#define SQUASHFS_COMPRESSED_BIT_BLOCK		(1 << 24)
+
+static inline s32 squashfs_compressed_size_block(s32 size)
+{
+	return size & ~SQUASHFS_COMPRESSED_BIT_BLOCK;
+}
+
+static inline bool squashfs_compressed_block(s32 size)
+{
+	return (size & SQUASHFS_COMPRESSED_BIT_BLOCK) == 0;
+}
+#endif
-- 
2.47.3