Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...

[pandora-kernel.git] / fs / ext4 / super.c

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index cc5c157..9ea71aa 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2243,6 +2243,12 @@ static void ext4_orphan_cleanup(struct super_block *sb,
  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
  * so that won't be a limiting factor.
  *
+ * However there is other limiting factor. We do store extents in the form
+ * of starting block and length, hence the resulting length of the extent
+ * covering maximum file size must fit into on-disk format containers as
+ * well. Given that length is always by 1 unit bigger than max unit (because
+ * we count 0 as well) we have to lower the s_maxbytes by one fs block.
+ *
  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
  */
 static loff_t ext4_max_size(int blkbits, int has_huge_files)
@@ -2264,10 +2270,13 @@ static loff_t ext4_max_size(int blkbits, int has_huge_files)
                upper_limit <<= blkbits;
        }
 
-       /* 32-bit extent-start container, ee_block */
-       res = 1LL << 32;
+       /*
+        * 32-bit extent-start container, ee_block. We lower the maxbytes
+        * by one fs block, so ee_len can cover the extent of maximum file
+        * size
+        */
+       res = (1LL << 32) - 1;
        res <<= blkbits;
-       res -= 1;
 
        /* Sanity check against vm- & vfs- imposed limits */
        if (res > upper_limit)