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| author | Kautuk Consul <consul.kautuk@gmail.com> | 2011-10-31 17:09:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-31 17:30:49 -0700 |
| commit | 3f380998aeb51b99d5d22cadb41162e1e9db70d2 (patch) | |
| tree | 1d5bb20368b06c7b86e7257771209795bd764f00 /mm | |
| parent | 4e9dc5df46001510ebd3b3e54faa650f474e51a3 (diff) | |
| download | lwn-3f380998aeb51b99d5d22cadb41162e1e9db70d2.tar.gz lwn-3f380998aeb51b99d5d22cadb41162e1e9db70d2.zip | |
vmscan.c: fix invalid strict_strtoul() check in write_scan_unevictable_node()
write_scan_unevictable_node() checks the value req returned by
strict_strtoul() and returns 1 if req is 0.
However, when strict_strtoul() returns 0, it means successful conversion
of buf to unsigned long.
Due to this, the function was not proceeding to scan the zones for
unevictable pages even though we write a valid value to the
scan_unevictable_pages sys file.
Change this check slightly to check for invalid value in buf as well as 0
value stored in res after successful conversion via strict_strtoul. In
both cases, we do not perform the scanning of this node's zones.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/vmscan.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 51bc4bf3f723..ac644fe85589 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3520,8 +3520,8 @@ static ssize_t write_scan_unevictable_node(struct sys_device *dev, unsigned long res; unsigned long req = strict_strtoul(buf, 10, &res); - if (!req) - return 1; /* zero is no-op */ + if (req || !res) + return 1; /* Invalid input or zero is no-op */ for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { if (!populated_zone(zone)) |