From: Qu Wenruo Date: Fri, 19 Nov 2021 06:19:33 +0000 (+0800) Subject: btrfs: don't check stripe length if the profile is not stripe based X-Git-Tag: v6.6.17~8077^2~119 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bf08387fb462ac7ab7dd4d3e4ac32728585bf625;p=platform%2Fkernel%2Flinux-rpi.git btrfs: don't check stripe length if the profile is not stripe based [BUG] When debugging calc_bio_boundaries(), I found that even for RAID1 metadata, we're following stripe length to calculate stripe boundary. # mkfs.btrfs -m raid1 -d raid1 /dev/test/scratch[12] # mount /dev/test/scratch /mnt/btrfs # xfs_io -f -c "pwrite 0 64K" /mnt/btrfs/file # umount Above very basic operations will make calc_bio_boundaries() to report the following result: submit_extent_page: r/i=1/1 file_offset=22036480 len_to_stripe_boundary=49152 submit_extent_page: r/i=1/1 file_offset=30474240 len_to_stripe_boundary=65536 ... submit_extent_page: r/i=1/1 file_offset=30523392 len_to_stripe_boundary=16384 submit_extent_page: r/i=1/1 file_offset=30457856 len_to_stripe_boundary=16384 submit_extent_page: r/i=5/257 file_offset=0 len_to_stripe_boundary=65536 submit_extent_page: r/i=5/257 file_offset=65536 len_to_stripe_boundary=65536 submit_extent_page: r/i=1/1 file_offset=30490624 len_to_stripe_boundary=49152 submit_extent_page: r/i=1/1 file_offset=30507008 len_to_stripe_boundary=32768 Where "r/i" is the rootid and inode, 1/1 means they metadata. The remaining names match the member used in kernel. Even all data/metadata are using RAID1, we're still following stripe length. [CAUSE] This behavior is caused by a wrong condition in btrfs_get_io_geometry(): if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { /* Fill using stripe_len */ len = min_t(u64, em->len - offset, max_len); } else { len = em->len - offset; } This means, only for SINGLE we will not follow stripe_len. However for profiles like RAID1*, DUP, they don't need to bother stripe_len. This can lead to unnecessary bio split for RAID1*/DUP profiles, and can even be a blockage for future zoned RAID support. [FIX] Introduce one single-use macro, BTRFS_BLOCK_GROUP_STRIPE_MASK, and change the condition to only calculate the length using stripe length for stripe based profiles. Reviewed-by: Johannes Thumshirn Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index cafd490..f463dd5 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -34,6 +34,10 @@ #include "discard.h" #include "zoned.h" +#define BTRFS_BLOCK_GROUP_STRIPE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \ + BTRFS_BLOCK_GROUP_RAID10 | \ + BTRFS_BLOCK_GROUP_RAID56_MASK) + const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = { [BTRFS_RAID_RAID10] = { .sub_stripes = 2, @@ -6347,7 +6351,8 @@ int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *em, stripe_offset = offset - stripe_offset; data_stripes = nr_data_stripes(map); - if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + /* Only stripe based profiles needs to check against stripe length. */ + if (map->type & BTRFS_BLOCK_GROUP_STRIPE_MASK) { u64 max_len = stripe_len - stripe_offset; /*