* [merged] swap-warn-when-a-swap-area-overflows-the-maximum-size.patch removed from -mm tree
@ 2013-09-12 19:42 akpm
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From: akpm @ 2013-09-12 19:42 UTC (permalink / raw
To: mm-commits, valdis.kletnieks, riel, hughd, shentino
Subject: [merged] swap-warn-when-a-swap-area-overflows-the-maximum-size.patch removed from -mm tree
To: shentino@gmail.com,hughd@google.com,riel@redhat.com,valdis.kletnieks@vt.edu,mm-commits@vger.kernel.org
From: akpm@linux-foundation.org
Date: Thu, 12 Sep 2013 12:42:15 -0700
The patch titled
Subject: swap: warn when a swap area overflows the maximum size
has been removed from the -mm tree. Its filename was
swap-warn-when-a-swap-area-overflows-the-maximum-size.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Raymond Jennings <shentino@gmail.com>
Subject: swap: warn when a swap area overflows the maximum size
It is possible to swapon a swap area that is too big for the pte width
to handle.
Presently this failure happens silently.
Instead, emit a diagnostic to warn the user.
Testing results, root prompt commands and kernel log messages:
# lvresize /dev/system/swap --size 16G
# mkswap /dev/system/swap
# swapon /dev/system/swap
Jul 7 04:27:22 warfang kernel: Adding 16777212k swap
on /dev/mapper/system-swap. Priority:-1 extents:1 across:16777212k
# lvresize /dev/system/swap --size 64G
# mkswap /dev/system/swap
# swapon /dev/system/swap
Jul 7 04:27:22 warfang kernel: Truncating oversized swap area, only
using 33554432k out of 67108860k
Jul 7 04:27:22 warfang kernel: Adding 33554428k swap
on /dev/mapper/system-swap. Priority:-1 extents:1 across:33554428k
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Raymond Jennings <shentino@gmail.com>
Acked-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/swapfile.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff -puN mm/swapfile.c~swap-warn-when-a-swap-area-overflows-the-maximum-size mm/swapfile.c
--- a/mm/swapfile.c~swap-warn-when-a-swap-area-overflows-the-maximum-size
+++ a/mm/swapfile.c
@@ -1926,6 +1926,7 @@ static unsigned long read_swap_header(st
int i;
unsigned long maxpages;
unsigned long swapfilepages;
+ unsigned long last_page;
if (memcmp("SWAPSPACE2", swap_header->magic.magic, 10)) {
printk(KERN_ERR "Unable to find swap-space signature\n");
@@ -1968,8 +1969,15 @@ static unsigned long read_swap_header(st
*/
maxpages = swp_offset(pte_to_swp_entry(
swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
- if (maxpages > swap_header->info.last_page) {
- maxpages = swap_header->info.last_page + 1;
+ last_page = swap_header->info.last_page;
+ if (last_page > maxpages) {
+ printk(KERN_WARNING
+ "Truncating oversized swap area, only using %luk out of %luk\n",
+ maxpages << (PAGE_SHIFT - 10),
+ last_page << (PAGE_SHIFT - 10));
+ }
+ if (maxpages > last_page) {
+ maxpages = last_page + 1;
/* p->max is an unsigned int: don't overflow it */
if ((unsigned int)maxpages == 0)
maxpages = UINT_MAX;
_
Patches currently in -mm which might be from shentino@gmail.com are
origin.patch
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2013-09-12 19:42 [merged] swap-warn-when-a-swap-area-overflows-the-maximum-size.patch removed from -mm tree akpm
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