From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: [PATCH 1/4] vfs: Remove useless loop in mntput_no_expire Date: Mon, 14 Apr 2014 00:40:03 -0700 Message-ID: <87sipguzos.fsf_-_@x220.int.ebiederm.org> References: <87sipmbe8x.fsf@x220.int.ebiederm.org> <20140409175322.GZ18016@ZenIV.linux.org.uk> <20140409182830.GA18016@ZenIV.linux.org.uk> <87txa286fu.fsf@x220.int.ebiederm.org> <87fvlm860e.fsf_-_@x220.int.ebiederm.org> <20140409232423.GB18016@ZenIV.linux.org.uk> <87lhva5h4k.fsf@x220.int.ebiederm.org> <20140413053956.GM18016@ZenIV.linux.org.uk> <87zjjp3e7w.fsf@x220.int.ebiederm.org> <87ppkl1xb7.fsf@x220.int.ebiederm.org> <20140413215242.GP18016@ZenIV.linux.org.uk> <87y4z8uzqw.fsf_-_@x220.int.ebiederm.org> Mime-Version: 1.0 Content-Type: text/plain Cc: Linus Torvalds , "Serge E. Hallyn" , Linux-Fsdevel , Kernel Mailing List , Andy Lutomirski , Rob Landley , Miklos Szeredi , Christoph Hellwig , Karel Zak , "J. Bruce Fields" , Fengguang Wu , tytso@mit.edu To: Al Viro Return-path: In-Reply-To: <87y4z8uzqw.fsf_-_@x220.int.ebiederm.org> (Eric W. Biederman's message of "Mon, 14 Apr 2014 00:38:47 -0700") Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Remove the extra reference added to mnt_count by the mnt_pinned code, and stop jumping to the top of mntput_no_expire. When fput synchronously called mntput that extra reference count and the loop ensured that after acct_auto_close_mnt closed all of the pinned references mntput_no_expire would then proceed actually unmount the filesystem. As fput is asynchronous today there is no point in looping. Signed-off-by: "Eric W. Biederman" --- fs/namespace.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 9d0eb6b4e7d5..2abd5a2416d0 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -985,7 +985,6 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root, static void mntput_no_expire(struct mount *mnt) { -put_again: rcu_read_lock(); mnt_add_count(mnt, -1); if (likely(mnt->mnt_ns)) { /* shouldn't be the last one */ @@ -999,12 +998,12 @@ put_again: return; } if (unlikely(mnt->mnt_pinned)) { - mnt_add_count(mnt, mnt->mnt_pinned + 1); + mnt_add_count(mnt, mnt->mnt_pinned); mnt->mnt_pinned = 0; rcu_read_unlock(); unlock_mount_hash(); acct_auto_close_mnt(&mnt->mnt); - goto put_again; + return; } if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) { rcu_read_unlock(); -- 1.9.1