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>

1 files changed, 15 insertions, 7 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7910e61809e7..143d763729b4 100644
--- 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 */