From 19b0092e265fe9ab129902373c3127c0e0be3376 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 5 Apr 2013 15:36:34 +0100 Subject: [PATCH] dm cache: reduce bio front_pad size in writeback mode A recent patch to fix the dm cache target's writethrough mode extended the bio's front_pad to include a 1056-byte struct dm_bio_details. Writeback mode doesn't need this, so this patch reduces the per_bio_data_size to 16 bytes in this case instead of 1096. The dm_bio_details structure was added in "dm cache: fix writes to cache device in writethrough mode" which fixed commit e2e74d617e ("dm cache: fix race in writethrough implementation"). In writeback mode we avoid allocating the writethrough-specific members of the per_bio_data structure (the dm_bio_details structure included). Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- Reading git-format-patch failed