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From: John Ogness <john.ogness@linutronix.de>
To: linux-fsdevel@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Christoph Hellwig <hch@lst.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 2/4] fs/dcache: Move dentry_kill() below lock_parent()
Date: Fri, 16 Feb 2018 16:09:31 +0100	[thread overview]
Message-ID: <20180216150933.971-3-john.ogness@linutronix.de> (raw)
In-Reply-To: <20180216150933.971-1-john.ogness@linutronix.de>

A subsequent patch will modify dentry_kill() to call lock_parent().
Move the dentry_kill() implementation "as is" below lock_parent()
first. This will help simplify the review of the subsequent patch
with dentry_kill() changes.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 fs/dcache.c | 62 ++++++++++++++++++++++++++++++-------------------------------
 1 file changed, 31 insertions(+), 31 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 3c7e0148b453..9fed398687c9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -589,37 +589,6 @@ static void __dentry_kill(struct dentry *dentry)
 		dentry_free(dentry);
 }
 
-/*
- * Finish off a dentry we've decided to kill.
- * dentry->d_lock must be held, returns with it unlocked.
- * Returns dentry requiring refcount drop, or NULL if we're done.
- */
-static struct dentry *dentry_kill(struct dentry *dentry)
-	__releases(dentry->d_lock)
-{
-	struct inode *inode = dentry->d_inode;
-	struct dentry *parent = NULL;
-
-	if (inode && unlikely(!spin_trylock(&inode->i_lock)))
-		goto failed;
-
-	if (!IS_ROOT(dentry)) {
-		parent = dentry->d_parent;
-		if (unlikely(!spin_trylock(&parent->d_lock))) {
-			if (inode)
-				spin_unlock(&inode->i_lock);
-			goto failed;
-		}
-	}
-
-	__dentry_kill(dentry);
-	return parent;
-
-failed:
-	spin_unlock(&dentry->d_lock);
-	return dentry; /* try again with same dentry */
-}
-
 static inline struct dentry *lock_parent(struct dentry *dentry)
 {
 	struct dentry *parent = dentry->d_parent;
@@ -655,6 +624,37 @@ static inline struct dentry *lock_parent(struct dentry *dentry)
 }
 
 /*
+ * Finish off a dentry we've decided to kill.
+ * dentry->d_lock must be held, returns with it unlocked.
+ * Returns dentry requiring refcount drop, or NULL if we're done.
+ */
+static struct dentry *dentry_kill(struct dentry *dentry)
+	__releases(dentry->d_lock)
+{
+	struct inode *inode = dentry->d_inode;
+	struct dentry *parent = NULL;
+
+	if (inode && unlikely(!spin_trylock(&inode->i_lock)))
+		goto failed;
+
+	if (!IS_ROOT(dentry)) {
+		parent = dentry->d_parent;
+		if (unlikely(!spin_trylock(&parent->d_lock))) {
+			if (inode)
+				spin_unlock(&inode->i_lock);
+			goto failed;
+		}
+	}
+
+	__dentry_kill(dentry);
+	return parent;
+
+failed:
+	spin_unlock(&dentry->d_lock);
+	return dentry; /* try again with same dentry */
+}
+
+/*
  * Try to do a lockless dput(), and return whether that was successful.
  *
  * If unsuccessful, we return false, having already taken the dentry lock.
-- 
2.11.0

  parent reply	other threads:[~2018-02-16 15:10 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-16 15:09 [PATCH 0/4] fs/dcache: avoid trylock loops John Ogness
2018-02-16 15:09 ` [PATCH 1/4] fs/dcache: Remove stale comment from dentry_kill() John Ogness
2018-02-16 15:09 ` John Ogness [this message]
2018-02-16 15:09 ` [PATCH 3/4] fs/dcache: Avoid the try_lock loop in d_delete() John Ogness
2018-02-16 17:10   ` Peter Zijlstra
2018-02-16 17:30   ` Peter Zijlstra
2018-02-22  5:18   ` Al Viro
2018-02-22  8:35     ` John Ogness
2018-02-16 15:09 ` [PATCH 4/4] fs/dcache: Avoid the try_lock loops in dentry_kill() John Ogness
2018-02-16 18:03   ` Linus Torvalds
2018-02-16 22:32     ` John Ogness
2018-02-16 22:42       ` Linus Torvalds
2018-02-16 23:05         ` John Ogness
2018-02-16 23:31           ` Linus Torvalds
2018-02-16 23:49             ` John Ogness
2018-02-17  0:06               ` Linus Torvalds
2018-02-19 23:34                 ` John Ogness
2018-02-20  0:42                   ` Linus Torvalds
2018-02-20  8:39                   ` Peter Zijlstra
2018-02-20  8:43                     ` Peter Zijlstra
2018-02-22  5:29                   ` Al Viro
2018-02-22  5:40     ` Al Viro

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