From: Ian Kent <raven@themaw.net>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: autofs mailing list <autofs@vger.kernel.org>,
Kernel Mailing List <linux-kernel@vger.kernel.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Omar Sandoval <osandov@osandov.com>,
Al Viro <viro@ZenIV.linux.org.uk>
Subject: [PATCH 6/7] autofs - dont hold spin lock over direct mount expire
Date: Mon, 28 Nov 2016 10:12:14 +0800 [thread overview]
Message-ID: <148029913453.27779.15747032937407838983.stgit@pluto.themaw.net> (raw)
In-Reply-To: <148029910861.27779.4517883721395202453.stgit@pluto.themaw.net>
From: Ian Kent <ikent@redhat.com>
Commit 7cbdb4a286 altered the autofs indirect mount expire to
not hold a spin lock during the expire check.
The direct mount expire needs the same treatment because to
make autofs expires namespace aware may_umount_tree() needs to
to use a similar method to may_umount() when checking if a mount
tree is in use.
This means may_umount_tree() will end up taking the namespace_sem
for the check so the autofs direct mount expire won't be allowed
to hold a spin lock over the check.
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
---
fs/autofs4/expire.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 13178bf..57725d4 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -310,26 +310,29 @@ struct dentry *autofs4_expire_direct(struct super_block *sb,
now = jiffies;
timeout = sbi->exp_timeout;
- spin_lock(&sbi->fs_lock);
- ino = autofs4_dentry_ino(root);
- /* No point expiring a pending mount */
- if (ino->flags & AUTOFS_INF_PENDING)
- goto out;
if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
+ spin_lock(&sbi->fs_lock);
+ ino = autofs4_dentry_ino(root);
+ /* No point expiring a pending mount */
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ spin_unlock(&sbi->fs_lock);
+ goto out;
+ }
ino->flags |= AUTOFS_INF_WANT_EXPIRE;
spin_unlock(&sbi->fs_lock);
synchronize_rcu();
- spin_lock(&sbi->fs_lock);
if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
+ spin_lock(&sbi->fs_lock);
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
return root;
}
+ spin_lock(&sbi->fs_lock);
ino->flags &= ~AUTOFS_INF_WANT_EXPIRE;
+ spin_unlock(&sbi->fs_lock);
}
out:
- spin_unlock(&sbi->fs_lock);
dput(root);
return NULL;
next prev parent reply other threads:[~2016-11-28 2:12 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-28 2:11 [PATCH 1/7] vfs - merge path_is_mountpoint() and path_is_mountpoint_rcu() Ian Kent
2016-11-28 2:11 ` [PATCH 2/7] autofs - make struct path const in autofs4_dir_open() Ian Kent
2016-11-28 2:11 ` [PATCH 3/7] autofs - change struct path to const in autofs4_expire_wait() and autofs4_wait() Ian Kent
2016-11-28 2:12 ` [PATCH 4/7] vfs - change struct path to const in d_manage() Ian Kent
2016-11-28 2:12 ` [PATCH 5/7] vfs - constify path parameter of path_has_submounts() Ian Kent
2016-11-28 2:12 ` Ian Kent [this message]
2016-11-28 2:12 ` [PATCH 7/7] vfs - make may_umount_tree() mount propogation aware Ian Kent
2016-11-30 22:22 ` [PATCH 1/7] vfs - merge path_is_mountpoint() and path_is_mountpoint_rcu() Andrew Morton
2016-12-01 0:13 ` Ian Kent
2016-12-03 5:13 ` Al Viro
2016-12-03 23:29 ` Al Viro
2016-12-04 2:18 ` Ian Kent
2016-12-05 2:50 ` Ian Kent
2016-12-04 2:07 ` Ian Kent
2016-12-06 9:37 ` Ian Kent
2016-12-07 21:30 ` Eric W. Biederman
2016-12-08 3:29 ` Ian Kent
2016-12-08 4:28 ` Eric W. Biederman
2016-12-08 6:18 ` Ian Kent
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