is_vmalloc_addr(): Check if an address is within the vmalloc boundaries

[safe/jmp/linux-2.6] / fs / ext2 / super.c

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 154e25f..6abaf75 100644 (file)
--- 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;
 }