[PATCH 4.19 169/205] mm/swapfile.c: use kvzalloc for swap_info_struct allocation

From: Greg Kroah-Hartman
Date: Mon Nov 19 2018 - 11:37:40 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vasily Averin <vvs@xxxxxxxxxxxxx>

commit 873d7bcfd066663e3e50113dc4a0de19289b6354 upstream.

Commit a2468cc9bfdf ("swap: choose swap device according to numa node")
changed 'avail_lists' field of 'struct swap_info_struct' to an array.
In popular linux distros it increased size of swap_info_struct up to 40
Kbytes and now swap_info_struct allocation requires order-4 page.
Switch to kvzmalloc allows to avoid unexpected allocation failures.

Link: http://lkml.kernel.org/r/fc23172d-3c75-21e2-d551-8b1808cbe593@xxxxxxxxxxxxx
Fixes: a2468cc9bfdf ("swap: choose swap device according to numa node")
Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
Acked-by: Aaron Lu <aaron.lu@xxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
mm/swapfile.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2820,7 +2820,7 @@ static struct swap_info_struct *alloc_sw
unsigned int type;
int i;

- p = kzalloc(sizeof(*p), GFP_KERNEL);
+ p = kvzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return ERR_PTR(-ENOMEM);

@@ -2831,7 +2831,7 @@ static struct swap_info_struct *alloc_sw
}
if (type >= MAX_SWAPFILES) {
spin_unlock(&swap_lock);
- kfree(p);
+ kvfree(p);
return ERR_PTR(-EPERM);
}
if (type >= nr_swapfiles) {
@@ -2845,7 +2845,7 @@ static struct swap_info_struct *alloc_sw
smp_wmb();
nr_swapfiles++;
} else {
- kfree(p);
+ kvfree(p);
p = swap_info[type];
/*
* Do not memset this entry: a racing procfs swap_next()