From bfec07d0f8ed78b10df3ca3bc23e27de1166ea45 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Wed, 28 May 2014 08:56:09 +0800 Subject: f2fs: avoid overflow when large directory feathure is enabled When large directory feathure is enable, We have one case which could cause overflow in dir_buckets() as following: special case: level + dir_level >= 32 and level < MAX_DIR_HASH_DEPTH / 2. Here we define MAX_DIR_BUCKETS to limit the return value when the condition could trigger potential overflow. Changes from V1 o modify description of calculation in f2fs.txt suggested by Changman Lee. Suggested-by: Changman Lee Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- include/linux/f2fs_fs.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/f2fs_fs.h') diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index 8c03f71307c6..ba6f3127738f 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -394,6 +394,9 @@ typedef __le32 f2fs_hash_t; /* MAX level for dir lookup */ #define MAX_DIR_HASH_DEPTH 63 +/* MAX buckets in one level of dir */ +#define MAX_DIR_BUCKETS (1 << ((MAX_DIR_HASH_DEPTH / 2) - 1)) + #define SIZE_OF_DIR_ENTRY 11 /* by byte */ #define SIZE_OF_DENTRY_BITMAP ((NR_DENTRY_IN_BLOCK + BITS_PER_BYTE - 1) / \ BITS_PER_BYTE) -- cgit v1.2.3