[PATCH 2/2 V3] xfs: don't take addresses of packed xfs_rmap_key member

Eric Sandeen
2020-01-29T18:35:28Z

gcc now warns about taking an address of a packed structure member.

This happens here because of how be32_add_cpu() works; just open-code
the modification instead.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
V2: fix key-> vs rec-> derp derp thinko
V3: drop local temp variable, add comment

diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index fc78efa52c94..c6f6a7ec6121 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -187,7 +187,9 @@ xfs_rmapbt_init_high_key_from_rec(
adj = be32_to_cpu(rec->rmap.rm_blockcount) - 1;

key->rmap.rm_startblock = rec->rmap.rm_startblock;
- be32_add_cpu(&key->rmap.rm_startblock, adj);
+ /* do this manually to avoid gcc warning about alignment */
+ key->rmap.rm_startblock =
+ cpu_to_be32(be32_to_cpu(key->rmap.rm_startblock) - adj);
key->rmap.rm_owner = rec->rmap.rm_owner;
key->rmap.rm_offset = rec->rmap.rm_offset;
if (XFS_RMAP_NON_INODE_OWNER(be64_to_cpu(rec->rmap.rm_owner)) ||