[PATCH 04/10] btrfs: store precalculated csum_size in fs_info

[David Sterba <dsterba@suse.com>]

In many places we need the checksum size and it is inefficient to read
it from the raw superblock. Store the value into fs_info, actual use
will be in followup patches.  The size is u32 as it allows to generate
better assembly than with u16.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/ctree.h   | 1 +
 fs/btrfs/disk-io.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index a1a0b99c3530..1f2162fc1daa 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -932,6 +932,7 @@ struct btrfs_fs_info {
 	u32 nodesize;
 	u32 sectorsize;
 	u32 sectorsize_bits;
+	u32 csum_size;
 	u32 stripesize;
 
 	/* Block groups and devices containing active swapfiles. */
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4e67c122389c..25dbdfa8bc4b 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3078,6 +3078,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	fs_info->nodesize = nodesize;
 	fs_info->sectorsize = sectorsize;
 	fs_info->sectorsize_bits = ilog2(sectorsize);
+	fs_info->csum_size = btrfs_super_csum_size(disk_super);
 	fs_info->stripesize = stripesize;
 
 	/*
-- 
2.25.0