From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:38378 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750844AbeCNJY3 (ORCPT ); Wed, 14 Mar 2018 05:24:29 -0400 Subject: Re: [PATCH v2 2/2] btrfs: drop optimal argument from find_live_mirror() To: Anand Jain , linux-btrfs@vger.kernel.org References: <20180314082913.31503-1-anand.jain@oracle.com> <20180314082913.31503-2-anand.jain@oracle.com> From: Nikolay Borisov Message-ID: <2388f361-646e-a0bd-bf71-a2d149f83f6a@suse.com> Date: Wed, 14 Mar 2018 11:24:27 +0200 MIME-Version: 1.0 In-Reply-To: <20180314082913.31503-2-anand.jain@oracle.com> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 14.03.2018 10:29, Anand Jain wrote: > Drop optimal argument from the function find_live_mirror() > as we can deduce it in the function itself. Also rename > optimal to preferred_mirror. > > Signed-off-by: Anand Jain Reviewed-by: Nikolay Borisov > --- > I thought I have sent v2 to the ML. But now I realize I didn't. > v1->v2: > Accepts David's comment to rename %optimal. IMO, %preferred_mirror is > better than the suggested %fallback. > > fs/btrfs/volumes.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 9beea7c891a7..f1b7efbdcec1 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -5276,10 +5276,11 @@ int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, u64 logical, u64 len) > > static int find_live_mirror(struct btrfs_fs_info *fs_info, > struct map_lookup *map, int first, > - int optimal, int dev_replace_is_ongoing) > + int dev_replace_is_ongoing) > { > int i; > int num_stripes; > + int preferred_mirror; > int tolerance; > struct btrfs_device *srcdev; > > @@ -5291,6 +5292,8 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, > else > num_stripes = map->num_stripes; > > + preferred_mirror = first + current->pid % num_stripes; > + > if (dev_replace_is_ongoing && > fs_info->dev_replace.cont_reading_from_srcdev_mode == > BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID) > @@ -5304,9 +5307,9 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, > * mirror is available > */ > for (tolerance = 0; tolerance < 2; tolerance++) { > - if (map->stripes[optimal].dev->bdev && > - (tolerance || map->stripes[optimal].dev != srcdev)) > - return optimal; > + if (map->stripes[preferred_mirror].dev->bdev && > + (tolerance || map->stripes[preferred_mirror].dev != srcdev)) > + return preferred_mirror; > for (i = first; i < first + num_stripes; i++) { > if (map->stripes[i].dev->bdev && > (tolerance || map->stripes[i].dev != srcdev)) > @@ -5317,7 +5320,7 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, > /* we couldn't find one that doesn't fail. Just return something > * and the io error handling code will clean up eventually > */ > - return optimal; > + return preferred_mirror; > } > > static inline int parity_smaller(u64 a, u64 b) > @@ -5844,7 +5847,6 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > stripe_index = mirror_num - 1; > else { > stripe_index = find_live_mirror(fs_info, map, 0, > - current->pid % map->num_stripes, > dev_replace_is_ongoing); > mirror_num = stripe_index + 1; > } > @@ -5872,8 +5874,6 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > int old_stripe_index = stripe_index; > stripe_index = find_live_mirror(fs_info, map, > stripe_index, > - stripe_index + > - current->pid % map->sub_stripes, > dev_replace_is_ongoing); > mirror_num = stripe_index - old_stripe_index + 1; > } >