linux-kernel - [PATCH 1/4] autofs: dont call do_expire_wait() in autofs_d

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Date:   Thu, 26 Mar 2020 13:23:18 +0800
From:   Ian Kent <raven@...maw.net>
To:     Al Viro <viro@...IV.linux.org.uk>
Cc:     autofs mailing list <autofs@...r.kernel.org>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH 1/4] autofs: dont call do_expire_wait() in autofs_d_manage()

Calling do_expire_wait() in autofs_d_manage() isn't really necessary.

If in rcu-walk mode -ECHILD will be returned and if in ref-walk mode
and the dentry might be picked for expire (or is expiring) 0 will be
returned otherwise it waits for the expire.

But waiting is meant to be done in autofs_d_automount() so simplify
autofs_d_manage() by testing the expire status and returning only
what's needed.

Signed-off-by: Ian Kent <raven@...maw.net>
---
 fs/autofs/root.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/autofs/root.c b/fs/autofs/root.c
index 5aaa1732bf1e..a3b7c72a298d 100644
--- a/fs/autofs/root.c
+++ b/fs/autofs/root.c
@@ -410,9 +410,12 @@ static int autofs_d_manage(const struct path *path, bool rcu_walk)
 		return 0;
 	}
 
-	/* Wait for pending expires */
-	if (do_expire_wait(path, rcu_walk) == -ECHILD)
-		return -ECHILD;
+	/* Check for (possible) pending expire */
+	if (ino->flags & AUTOFS_INF_WANT_EXPIRE) {
+		if (rcu_walk)
+			return -ECHILD;
+		return 0;
+	}
 
 	/*
 	 * This dentry may be under construction so wait on mount
@@ -432,8 +435,6 @@ static int autofs_d_manage(const struct path *path, bool rcu_walk)
 		 */
 		struct inode *inode;
 
-		if (ino->flags & AUTOFS_INF_WANT_EXPIRE)
-			return 0;
 		if (path_is_mountpoint(path))
 			return 0;
 		inode = d_inode_rcu(dentry);