From: Barry Song <v-songbaohua@xxxxxxxx> The code is quite hard to read, we are still writing swap_map after errors happen. Though the written value is as before, has_cache = count & SWAP_HAS_CACHE; count &= ~SWAP_HAS_CACHE; [snipped] WRITE_ONCE(p->swap_map[offset], count | has_cache); It would be better to entirely drop the WRITE_ONCE for both performance and readability. Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx> --- -v2: drop goto according to Andrew, Thanks! mm/swapfile.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 556ff7347d5f..7cb6d9a2d51d 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3320,7 +3320,8 @@ static int __swap_duplicate(swp_entry_t entry, unsigned char usage) } else err = -ENOENT; /* unused swap entry */ - WRITE_ONCE(p->swap_map[offset], count | has_cache); + if (!err) + WRITE_ONCE(p->swap_map[offset], count | has_cache); unlock_out: unlock_cluster_or_swap_info(p, ci); -- 2.34.1
