1 files changed, 12 insertions, 3 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index cc5c157aa11..9ea71aa864b 100644
--- 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)