From: Huang Ying <ying.huang@xxxxxxxxx>
Mike reported the following warning messages
get_swap_device: Bad swap file entry 1400000000000001
This is produced by
- total_swapcache_pages()
- get_swap_device()
Where get_swap_device() is used to check whether the swap device is
valid and prevent it from being swapoff if so. But get_swap_device()
may produce warning message as above for some invalid swap devices.
This is fixed via calling swp_swap_info() before get_swap_device() to
filter out the swap devices that may cause warning messages.
Fixes: 6a946753dbe6 ("mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device()")
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
---
mm/swap_state.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/mm/swap_state.c b/mm/swap_state.c
index b84c58b572ca..62da25b7f2ed 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -76,8 +76,13 @@ unsigned long total_swapcache_pages(void)
struct swap_info_struct *si;
for (i = 0; i < MAX_SWAPFILES; i++) {
+ swp_entry_t entry = swp_entry(i, 1);
+
+ /* Avoid get_swap_device() to warn for bad swap entry */
+ if (!swp_swap_info(entry))
+ continue;
/* Prevent swapoff to free swapper_spaces */
- si = get_swap_device(swp_entry(i, 1));
+ si = get_swap_device(entry);
if (!si)
continue;
nr = nr_swapper_spaces[i];
--
2.20.1
