From: Karel Zak <kzak@redhat.com>
Date: Wed, 21 Sep 2016 12:47:32 +0000 (+0200)
Subject: swapon: fix discard option parsing
X-Git-Tag: v2.29-rc1~40
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=07332bfa1ec122a251194a62f91319841121d5aa;p=thirdparty%2Futil-linux.git

swapon: fix discard option parsing

The current code does not work as expected if there is an option
behind the discard=<arg>, for example:

  swapon /dev/sdc -o discard=once,pri=10

ignores "once" the result is SWAP_FLAG_DISCARD; strace:

Old version:

  swapon("/dev/sdc", SWAP_FLAG_PREFER|SWAP_FLAG_DISCARD|10) = 0

Fixed version:

  swapon("/dev/sdc", SWAP_FLAG_PREFER|SWAP_FLAG_DISCARD|SWAP_FLAG_DISCARD_ONCE|10) = 0

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/sys-utils/swapon.c b/sys-utils/swapon.c
index 62a776d401..0ee5caf448 100644
--- a/sys-utils/swapon.c
+++ b/sys-utils/swapon.c
@@ -688,6 +688,7 @@ static int swapon_by_uuid(struct swapon_ctl *ctl, const char *uuid)
 static int parse_options(struct swap_prop *props, const char *options)
 {
 	char *arg = NULL;
+	size_t argsz = 0;
 
 	assert(props);
 	assert(options);
@@ -695,16 +696,16 @@ static int parse_options(struct swap_prop *props, const char *options)
 	if (mnt_optstr_get_option(options, "nofail", NULL, 0) == 0)
 		props->no_fail = 1;
 
-	if (mnt_optstr_get_option(options, "discard", &arg, NULL) == 0) {
+	if (mnt_optstr_get_option(options, "discard", &arg, &argsz) == 0) {
 		props->discard |= SWAP_FLAG_DISCARD;
 
 		if (arg) {
 			/* only single-time discards are wanted */
-			if (strcmp(arg, "once") == 0)
+			if (strncmp(arg, "once", argsz) == 0)
 				props->discard |= SWAP_FLAG_DISCARD_ONCE;
 
 			/* do discard for every released swap page */
-			if (strcmp(arg, "pages") == 0)
+			if (strncmp(arg, "pages", argsz) == 0)
 				props->discard |= SWAP_FLAG_DISCARD_PAGES;
 		}
 	}