[PATCH 1/3] mm, swap: ratelimit bad swap entry reports in get_swap_device()

[Breno Leitao <leitao@debian.org>]

A corrupt page table hands the same bogus entry to get_swap_device() on
every access to the mapping, and every rejection is logged. One machine
logged 6185620 copies of the same line in a few hours.

Rate limit both prints.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 mm/swapfile.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 4d4e3e3059f6b..9ab11dc24e4f1 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1899,11 +1899,11 @@ struct swap_info_struct *get_swap_device(swp_entry_t entry)
 
 	return si;
 bad_nofile:
-	pr_err("%s: %s%08lx\n", __func__, Bad_file, entry.val);
+	pr_err_ratelimited("%s: %s%08lx\n", __func__, Bad_file, entry.val);
 out:
 	return NULL;
 put_out:
-	pr_err("%s: %s%08lx\n", __func__, Bad_offset, entry.val);
+	pr_err_ratelimited("%s: %s%08lx\n", __func__, Bad_offset, entry.val);
 	percpu_ref_put(&si->users);
 	return NULL;
 }

-- 
2.53.0-Meta