autofs: test autofs versions first on sb initialization

This patch does what the below comment says.  It could be and it's
considered better to do this first before various functions get called
during initialization.

/* Couldn't this be tested earlier? */

Link: http://lkml.kernel.org/r/20160812024744.12352.43075.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index ca9cbd6362e00144d0d3f2b59c9bbd85933e663e..d76573f622780756a097e575bb1132d899168b3a 100644 (file)
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -274,6 +274,23 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
                goto fail_dput;
        }
 
+       /* Test versions first */
+       if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
+           sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
+               pr_err("kernel does not match daemon version "
+                      "daemon (%d, %d) kernel (%d, %d)\n",
+                      sbi->min_proto, sbi->max_proto,
+                      AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
+               goto fail_dput;
+       }
+
+       /* Establish highest kernel protocol version */
+       if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
+               sbi->version = AUTOFS_MAX_PROTO_VERSION;
+       else
+               sbi->version = sbi->max_proto;
+       sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
+
        if (pgrp_set) {
                sbi->oz_pgrp = find_get_pid(pgrp);
                if (!sbi->oz_pgrp) {
@@ -291,23 +308,6 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
        root_inode->i_fop = &autofs4_root_operations;
        root_inode->i_op = &autofs4_dir_inode_operations;
 
-       /* Couldn't this be tested earlier? */
-       if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
-           sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
-               pr_err("kernel does not match daemon version "
-                      "daemon (%d, %d) kernel (%d, %d)\n",
-                      sbi->min_proto, sbi->max_proto,
-                      AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
-               goto fail_dput;
-       }
-
-       /* Establish highest kernel protocol version */
-       if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
-               sbi->version = AUTOFS_MAX_PROTO_VERSION;
-       else
-               sbi->version = sbi->max_proto;
-       sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
-
        pr_debug("pipe fd = %d, pgrp = %u\n", pipefd, pid_nr(sbi->oz_pgrp));
        pipe = fget(pipefd);