From: Hugh Dickins <hugh@veritas.com>
First of three small "stop swapoff" patches based on 2.5.67-mm3:
stop swapoff 1/3 vm_enough_memory?
Before embarking upon swapoff, check vm_enough_memory. Mainly
for consistency in the overcommit_memory 2 (strict accounting) case:
fail with -ENOMEM if it wouldn't let the amount removed be committed.
Will always succeed in the overcommit_memory 1 case, as it should in
root-shoot-foot mode. In the overcommit_memory 0 case, well, I don't
care much either way, so opted for the simplest code: no special case.
Which means it could now fail at the start; but that's unlikely (case 0
is over-generous) and only when it would have got stuck later on anyway.
25-akpm/mm/swapfile.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)
diff -puN mm/swapfile.c~overcommit-stop-swapoff mm/swapfile.c
--- 25/mm/swapfile.c~overcommit-stop-swapoff Thu Apr 17 15:02:01 2003
+++ 25-akpm/mm/swapfile.c Thu Apr 17 15:02:01 2003
@@ -7,6 +7,7 @@
#include <linux/config.h>
#include <linux/mm.h>
+#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/kernel_stat.h>
#include <linux/swap.h>
@@ -1029,12 +1030,18 @@ asmlinkage long sys_swapoff(const char _
}
prev = type;
}
- err = -EINVAL;
if (type < 0) {
+ err = -EINVAL;
+ swap_list_unlock();
+ goto out_dput;
+ }
+ if (vm_enough_memory(p->pages))
+ vm_unacct_memory(p->pages);
+ else {
+ err = -ENOMEM;
swap_list_unlock();
goto out_dput;
}
-
if (prev < 0) {
swap_list.head = p->next;
} else {
_