1 files changed, 28 insertions, 4 deletions

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 154e25f13d77..6abaf75163f0 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -680,11 +680,31 @@ static int ext2_check_descriptors (struct super_block * sb)
 static loff_t ext2_max_size(int bits)
 {
         loff_t res = EXT2_NDIR_BLOCKS;
-        /* This constant is calculated to be the largest file size for a
-         * dense, 4k-blocksize file such that the total number of
+        int meta_blocks;
+        loff_t upper_limit;
+
+        /* This is calculated to be the largest file size for a
+         * dense, file such that the total number of
          * sectors in the file, including data and all indirect blocks,
-         * does not exceed 2^32. */
-        const loff_t upper_limit = 0x1ff7fffd000LL;
+         * does not exceed 2^32 -1
+         * __u32 i_blocks representing the total number of
+         * 512 bytes blocks of the file
+         */
+        upper_limit = (1LL << 32) - 1;
+
+        /* total blocks in file system block size */
+        upper_limit >>= (bits - 9);
+
+
+        /* indirect blocks */
+        meta_blocks = 1;
+        /* double indirect blocks */
+        meta_blocks += 1 + (1LL << (bits-2));
+        /* tripple indirect blocks */
+        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
+
+        upper_limit -= meta_blocks;
+        upper_limit <<= bits;
 
         res += 1LL << (bits-2);
         res += 1LL << (2*(bits-2));
@@ -692,6 +712,10 @@ static loff_t ext2_max_size(int bits)
         res <<= bits;
         if (res > upper_limit)
                 res = upper_limit;
+
+        if (res > MAX_LFS_FILESIZE)
+                res = MAX_LFS_FILESIZE;
+
         return res;
 }