From 4886ff7b50f6341539611a1503a6ad2e55b77c98 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 20 Mar 2023 10:12:49 +0800 Subject: btrfs: introduce a new helper to submit write bio for repair Both scrub and read-repair are utilizing a special repair writes that: - Only writes back to a single device Even for read-repair on RAID56, we only update the corrupted data stripe itself, not triggering the full RMW path. - Requires a valid @mirror_num For RAID56 case, only @mirror_num == 1 is valid. For non-RAID56 cases, we need @mirror_num to locate our stripe. - No data csum generation needed These two call sites still have some differences though: - Read-repair goes plain bio It doesn't need a full btrfs_bio, and goes submit_bio_wait(). - New scrub repair would go btrfs_bio To simplify both read and write path. So here this patch would: - Introduce a common helper, btrfs_map_repair_block() Due to the single device nature, we can use an on-stack btrfs_io_stripe to pass device and its physical bytenr. - Introduce a new interface, btrfs_submit_repair_bio(), for later scrub code This is for the incoming scrub code. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/raid56.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/btrfs/raid56.h') diff --git a/fs/btrfs/raid56.h b/fs/btrfs/raid56.h index df0e0abdeb1f..6583c225b1bd 100644 --- a/fs/btrfs/raid56.h +++ b/fs/btrfs/raid56.h @@ -170,6 +170,11 @@ static inline int nr_data_stripes(const struct map_lookup *map) return map->num_stripes - btrfs_nr_parity_stripes(map->type); } +static inline int nr_bioc_data_stripes(const struct btrfs_io_context *bioc) +{ + return bioc->num_stripes - btrfs_nr_parity_stripes(bioc->map_type); +} + #define RAID5_P_STRIPE ((u64)-2) #define RAID6_Q_STRIPE ((u64)-1) -- cgit v1.2.3-73-gaa49b