fs: warn about impending deprecation of mandatory locks

jtlayton · Sasha Levin · commit 0febcf95cb27 · 2021-08-26T08:37:29.000-04:00
[ Upstream commit fdd92b64d15bc4aec973caa25899afd782402e68 ]

We've had CONFIG_MANDATORY_FILE_LOCKING since 2015 and a lot of distros
have disabled it. Warn the stragglers that still use "-o mand" that
we'll be dropping support for that mount option.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton &lt;jlayton@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
diff --git a/fs/namespace.c b/fs/namespace.c
@@ -1670,8 +1670,12 @@ static inline bool may_mount(void)
 }
 
 #ifdef	CONFIG_MANDATORY_FILE_LOCKING
-static inline bool may_mandlock(void)
+static bool may_mandlock(void)
 {
+	pr_warn_once("======================================================\n"
+		     "WARNING: the mand mount option is being deprecated and\n"
+		     "         will be removed in v5.15!\n"
+		     "======================================================\n");
 	return capable(CAP_SYS_ADMIN);
 }
 #else

Original file line number	Diff line number	Diff line change
`@@ -1670,8 +1670,12 @@ static inline bool may_mount(void)`
`1670`	`1670`	`}`
`1671`	`1671`
`1672`	`1672`	`#ifdef CONFIG_MANDATORY_FILE_LOCKING`
`1673`		`-static inline bool may_mandlock(void)`
	`1673`	`+static bool may_mandlock(void)`
`1674`	`1674`	`{`
	`1675`	`+ pr_warn_once("======================================================\n"`
	`1676`	`+ "WARNING: the mand mount option is being deprecated and\n"`
	`1677`	`+ " will be removed in v5.15!\n"`
	`1678`	`+ "======================================================\n");`
`1675`	`1679`	`return capable(CAP_SYS_ADMIN);`
`1676`	`1680`	`}`
`1677`	`1681`	`#else`