fs: warn about impending deprecation of mandatory locks

jtlayton · jtlayton · commit fdd92b64d15b · 2021-08-21T07:32:45.000-04:00
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;
diff --git a/fs/namespace.c b/fs/namespace.c
@@ -1716,8 +1716,12 @@ 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
`@@ -1716,8 +1716,12 @@ static inline bool may_mount(void)`
`1716`	`1716`	`}`
`1717`	`1717`
`1718`	`1718`	`#ifdef CONFIG_MANDATORY_FILE_LOCKING`
`1719`		`-static inline bool may_mandlock(void)`
	`1719`	`+static bool may_mandlock(void)`
`1720`	`1720`	`{`
	`1721`	`+ pr_warn_once("======================================================\n"`
	`1722`	`+ "WARNING: the mand mount option is being deprecated and\n"`
	`1723`	`+ " will be removed in v5.15!\n"`
	`1724`	`+ "======================================================\n");`
`1721`	`1725`	`return capable(CAP_SYS_ADMIN);`
`1722`	`1726`	`}`
`1723`	`1727`	`#else`