ext4: ignore a stripe width of 1

If the stripe width was set to 1, then this patch will ignore
that stripe width and ext4 will act as if the stripe width
were 0 with respect to optimizing allocations.

Signed-off-by: Dan Ehrenberg <dehrenberg@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7910e61..143d763 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2384,17 +2384,25 @@ static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
        unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
        unsigned long stripe_width =
                        le32_to_cpu(sbi->s_es->s_raid_stripe_width);
+       int ret;
 
        if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
-               return sbi->s_stripe;
-
-       if (stripe_width <= sbi->s_blocks_per_group)
-               return stripe_width;
+               ret = sbi->s_stripe;
+       else if (stripe_width <= sbi->s_blocks_per_group)
+               ret = stripe_width;
+       else if (stride <= sbi->s_blocks_per_group)
+               ret = stride;
+       else
+               ret = 0;
 
-       if (stride <= sbi->s_blocks_per_group)
-               return stride;
+       /*
+        * If the stripe width is 1, this makes no sense and
+        * we set it to 0 to turn off stripe handling code.
+        */
+       if (ret <= 1)
+               ret = 0;
 
-       return 0;
+       return ret;
 }
 
 /* sysfs supprt */