diff options
authorShaohua Li <shli@kernel.org>2012-03-21 16:34:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-21 17:55:00 -0700
commit052b1987faca3606109d88d96bce124851f7c4c2 (patch)
parent1480de0340a8d5f094b74d7c4b902456c9a06903 (diff)
swap: don't do discard if no discard option added
When swapon() was not passed the SWAP_FLAG_DISCARD option, sys_swapon() will still perform a discard operation. This can cause problems if discard is slow or buggy. Reverse the order of the check so that a discard operation is performed only if the sys_swapon() caller is attempting to enable discard. Signed-off-by: Shaohua Li <shli@fusionio.com> Reported-by: Holger Kiehl <Holger.Kiehl@dwd.de> Tested-by: Holger Kiehl <Holger.Kiehl@dwd.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index b82c028cfcc..21b56945c5d 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2103,7 +2103,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
p->flags |= SWP_SOLIDSTATE;
p->cluster_next = 1 + (random32() % p->highest_bit);
- if (discard_swap(p) == 0 && (swap_flags & SWAP_FLAG_DISCARD))
+ if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
p->flags |= SWP_DISCARDABLE;