f2fs-tools: Refactor f2fs_dentry_block struct

This moves access to f2fs_dentry_block's dentry list and filename list
behind a macro, as their locations depend on block size.

Since struct f2fs_dentry_block no longer represents the full block, use
F2FS_BLKSIZE instead of sizeof(struct f2fs_dentry_block)

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

4 files changed, 65 insertions, 47 deletions

diff --git a/fsck/dir.c b/fsck/dir.c
index 64beaad..21d9da3 100644
--- a/fsck/dir.c
+++ b/fsck/dir.c
@@ -43,8 +43,8 @@ void make_dentry_ptr(struct f2fs_dentry_ptr *d, struct f2fs_node *node_blk,
 		d->max = NR_DENTRY_IN_BLOCK;
 		d->nr_bitmap = SIZE_OF_DENTRY_BITMAP;
 		d->bitmap = t->dentry_bitmap;
-		d->dentry = t->dentry;
-		d->filename = t->filename;
+		d->dentry = F2FS_DENTRY_BLOCK_DENTRIES(t);
+		d->filename = F2FS_DENTRY_BLOCK_FILENAMES(t);
 	} else {
 		int entry_cnt = NR_INLINE_DENTRY(node_blk);
 		int bitmap_size = INLINE_DENTRY_BITMAP_SIZE(node_blk);
@@ -352,17 +352,17 @@ static void make_empty_dir(struct f2fs_sb_info *sbi, struct f2fs_node *inode)
 	dent_blk = calloc(BLOCK_SZ, 1);
 	ASSERT(dent_blk);
 
-	dent_blk->dentry[0].hash_code = 0;
-	dent_blk->dentry[0].ino = cpu_to_le32(ino);
-	dent_blk->dentry[0].name_len = cpu_to_le16(1);
-	dent_blk->dentry[0].file_type = F2FS_FT_DIR;
-	memcpy(dent_blk->filename[0], ".", 1);
-
-	dent_blk->dentry[1].hash_code = 0;
-	dent_blk->dentry[1].ino = cpu_to_le32(pino);
-	dent_blk->dentry[1].name_len = cpu_to_le16(2);
-	dent_blk->dentry[1].file_type = F2FS_FT_DIR;
-	memcpy(dent_blk->filename[1], "..", 2);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).hash_code = 0;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).ino = cpu_to_le32(ino);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).name_len = cpu_to_le16(1);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).file_type = F2FS_FT_DIR;
+	memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 0), ".", 1);
+
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).hash_code = 0;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).ino = cpu_to_le32(pino);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).name_len = cpu_to_le16(2);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).file_type = F2FS_FT_DIR;
+	memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 1), "..", 2);
 
 	test_and_set_bit_le(0, dent_blk->dentry_bitmap);
 	test_and_set_bit_le(1, dent_blk->dentry_bitmap);
diff --git a/fsck/fsck.c b/fsck/fsck.c
index d791478..4dcdca6 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -1963,7 +1963,7 @@ int fsck_chk_dentry_blk(struct f2fs_sb_info *sbi, int casefolded, u32 blk_addr,
 
 	dentries = __chk_dentries(sbi, casefolded, child,
 			de_blk->dentry_bitmap,
-			de_blk->dentry, de_blk->filename,
+			F2FS_DENTRY_BLOCK_DENTRIES(de_blk), F2FS_DENTRY_BLOCK_FILENAMES(de_blk),
 			NR_DENTRY_IN_BLOCK, last_blk, enc_name);
 
 	if (dentries < 0 && f2fs_dev_is_writable()) {
diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index 2b8999e..1c5caa0 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -1372,16 +1372,29 @@ struct f2fs_dir_entry {
 
 static_assert(sizeof(struct f2fs_dir_entry) == 11, "");
 
-/* 4KB-sized directory entry block */
+/*
+ * Block-sized directory entry block
+ * On disk structure:
+ * struct f2fs_dentry_block;
+ * __u8 reserved[SIZE_OF_RESERVED];
+ * struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
+ * __u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
+ *
+ * Do NOT use sizeof. Use F2FS_BLKSIZE instead
+ */
 struct f2fs_dentry_block {
 	/* validity bitmap for directory entries in each block */
-	__u8 dentry_bitmap[SIZE_OF_DENTRY_BITMAP];
-	__u8 reserved[SIZE_OF_RESERVED];
-	struct f2fs_dir_entry dentry[NR_DENTRY_IN_BLOCK];
-	__u8 filename[NR_DENTRY_IN_BLOCK][F2FS_SLOT_LEN];
+	__u8 dentry_bitmap[0]; /* size is SIZE_OF_DENTRY_BITMAP, based on block size */
 };
 
-static_assert(sizeof(struct f2fs_dentry_block) == F2FS_BLKSIZE, "");
+#define F2FS_DENTRY_BLOCK_DENTRIES(blk) ((struct f2fs_dir_entry *)\
+			&((blk)->dentry_bitmap[SIZE_OF_DENTRY_BITMAP + SIZE_OF_RESERVED]))
+#define F2FS_DENTRY_BLOCK_DENTRY(blk, i) (F2FS_DENTRY_BLOCK_DENTRIES((blk))[(i)])
+
+#define F2FS_DENTRY_BLOCK_FILENAMES(blk) ((__u8(*)[F2FS_SLOT_LEN])&F2FS_DENTRY_BLOCK_DENTRY(blk,\
+							NR_DENTRY_IN_BLOCK))
+#define F2FS_DENTRY_BLOCK_FILENAME(blk, i) (&((__u8 *)&F2FS_DENTRY_BLOCK_DENTRY(blk,\
+							NR_DENTRY_IN_BLOCK))[(i) * F2FS_SLOT_LEN])
 
 /* for inline stuff */
 #define DEF_INLINE_RESERVED_SIZE	1
@@ -2050,6 +2063,11 @@ static inline void check_block_struct_sizes(void)
 	assert(sizeof(struct f2fs_summary) * ENTRIES_IN_SUM + sizeof(__le64)
 			+ offsetof(struct f2fs_journal, info)
 			+ EXTRA_INFO_RESERVED + sizeof(struct summary_footer) == F2FS_BLKSIZE);
+
+	/* Check Dentry Block Size */
+	assert(sizeof(__u8) * (SIZE_OF_DENTRY_BITMAP + SIZE_OF_RESERVED)
+			+ NR_DENTRY_IN_BLOCK * sizeof(struct f2fs_dir_entry)
+			+ NR_DENTRY_IN_BLOCK * F2FS_SLOT_LEN * sizeof(u8) == F2FS_BLKSIZE);
 }
 
 #endif	/*__F2FS_FS_H */
diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 740e752..f2840c8 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -1217,17 +1217,17 @@ static block_t f2fs_add_default_dentry_root(void)
 		return 0;
 	}
 
-	dent_blk->dentry[0].hash_code = 0;
-	dent_blk->dentry[0].ino = sb->root_ino;
-	dent_blk->dentry[0].name_len = cpu_to_le16(1);
-	dent_blk->dentry[0].file_type = F2FS_FT_DIR;
-	memcpy(dent_blk->filename[0], ".", 1);
-
-	dent_blk->dentry[1].hash_code = 0;
-	dent_blk->dentry[1].ino = sb->root_ino;
-	dent_blk->dentry[1].name_len = cpu_to_le16(2);
-	dent_blk->dentry[1].file_type = F2FS_FT_DIR;
-	memcpy(dent_blk->filename[1], "..", 2);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).hash_code = 0;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).ino = sb->root_ino;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).name_len = cpu_to_le16(1);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).file_type = F2FS_FT_DIR;
+	memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 0), ".", 1);
+
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).hash_code = 0;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).ino = sb->root_ino;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).name_len = cpu_to_le16(2);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).file_type = F2FS_FT_DIR;
+	memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 1), "..", 2);
 
 	/* bitmap for . and .. */
 	test_and_set_bit_le(0, dent_blk->dentry_bitmap);
@@ -1237,13 +1237,13 @@ static block_t f2fs_add_default_dentry_root(void)
 		int len = strlen(LPF);
 		f2fs_hash_t hash = f2fs_dentry_hash(0, 0, (unsigned char *)LPF, len);
 
-		dent_blk->dentry[2].hash_code = cpu_to_le32(hash);
-		dent_blk->dentry[2].ino = cpu_to_le32(c.lpf_ino);
-		dent_blk->dentry[2].name_len = cpu_to_le16(len);
-		dent_blk->dentry[2].file_type = F2FS_FT_DIR;
-		memcpy(dent_blk->filename[2], LPF, F2FS_SLOT_LEN);
+		F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 2).hash_code = cpu_to_le32(hash);
+		F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 2).ino = cpu_to_le32(c.lpf_ino);
+		F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 2).name_len = cpu_to_le16(len);
+		F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 2).file_type = F2FS_FT_DIR;
+		memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 2), LPF, F2FS_SLOT_LEN);
 
-		memcpy(dent_blk->filename[3], &LPF[F2FS_SLOT_LEN],
+		memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 3), &LPF[F2FS_SLOT_LEN],
 				len - F2FS_SLOT_LEN);
 
 		test_and_set_bit_le(2, dent_blk->dentry_bitmap);
@@ -1494,17 +1494,17 @@ static block_t f2fs_add_default_dentry_lpf(void)
 		return 0;
 	}
 
-	dent_blk->dentry[0].hash_code = 0;
-	dent_blk->dentry[0].ino = cpu_to_le32(c.lpf_ino);
-	dent_blk->dentry[0].name_len = cpu_to_le16(1);
-	dent_blk->dentry[0].file_type = F2FS_FT_DIR;
-	memcpy(dent_blk->filename[0], ".", 1);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).hash_code = 0;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).ino = cpu_to_le32(c.lpf_ino);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).name_len = cpu_to_le16(1);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 0).file_type = F2FS_FT_DIR;
+	memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 0), ".", 1);
 
-	dent_blk->dentry[1].hash_code = 0;
-	dent_blk->dentry[1].ino = sb->root_ino;
-	dent_blk->dentry[1].name_len = cpu_to_le16(2);
-	dent_blk->dentry[1].file_type = F2FS_FT_DIR;
-	memcpy(dent_blk->filename[1], "..", 2);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).hash_code = 0;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).ino = sb->root_ino;
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).name_len = cpu_to_le16(2);
+	F2FS_DENTRY_BLOCK_DENTRY(dent_blk, 1).file_type = F2FS_FT_DIR;
+	memcpy(F2FS_DENTRY_BLOCK_FILENAME(dent_blk, 1), "..", 2);
 
 	test_and_set_bit_le(0, dent_blk->dentry_bitmap);
 	test_and_set_bit_le(1, dent_blk->dentry_bitmap);