[patch] honour MNT_NOEXEC for access()

[Stas Sergeev]

Hi Andrew.

The attached patch makes the access(X_OK) to take the
"noexec" mount option into an account.

Signed-off-by: Stas Sergeev <stsp@xxxxxxxx>
CC: Jakub Jelinek <jakub@xxxxxxxxxx>
CC: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
CC: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
CC: Hugh Dickins <hugh@xxxxxxxxxxx>
CC: Ulrich Drepper <drepper@xxxxxxxxxx>

--- a/fs/namei.c	2006-08-29 14:15:47.000000000 +0400
+++ b/fs/namei.c	2006-10-04 11:28:52.000000000 +0400
@@ -249,9 +249,11 @@
 
 	/*
 	 * MAY_EXEC on regular files requires special handling: We override
-	 * filesystem execute permissions if the mode bits aren't set.
+	 * filesystem execute permissions if the mode bits aren't set or
+	 * the fs is mounted with the "noexec" flag.
 	 */
-	if ((mask & MAY_EXEC) && S_ISREG(mode) && !(mode & S_IXUGO))
+	if ((mask & MAY_EXEC) && S_ISREG(mode) && (!(mode & S_IXUGO) ||
+			(nd && nd->mnt && (nd->mnt->mnt_flags & MNT_NOEXEC))))
 		return -EACCES;
 
 	/* Ordinary permission routines do not understand MAY_APPEND. */