From: Ian Kent <raven@themaw.net>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Tejun Heo <tj@kernel.org>
Cc: Eric Sandeen <sandeen@sandeen.net>,
Fox Chen <foxhlchen@gmail.com>,
Brice Goglin <brice.goglin@gmail.com>,
Al Viro <viro@ZenIV.linux.org.uk>,
Rick Lindsley <ricklind@linux.vnet.ibm.com>,
David Howells <dhowells@redhat.com>,
Miklos Szeredi <miklos@szeredi.hu>,
Marcelo Tosatti <mtosatti@redhat.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Carlos Maiolino <cmaiolino@redhat.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH v7 1/6] kernfs: move revalidate to be near lookup
Date: Tue, 15 Jun 2021 18:25:53 +0800 [thread overview]
Message-ID: <162375275365.232295.8995526416263659926.stgit@web.messagingengine.com> (raw)
In-Reply-To: <162375263398.232295.14755578426619198534.stgit@web.messagingengine.com>
While the dentry operation kernfs_dop_revalidate() is grouped with
dentry type functions it also has a strong affinity to the inode
operation ->lookup().
It makes sense to locate this function near to kernfs_iop_lookup()
because we will be adding VFS negative dentry caching to reduce path
lookup overhead for non-existent paths.
There's no functional change from this patch.
Signed-off-by: Ian Kent <raven@themaw.net>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/kernfs/dir.c | 86 ++++++++++++++++++++++++++++---------------------------
1 file changed, 43 insertions(+), 43 deletions(-)
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 7e0e62deab53c..33166ec90a112 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -548,49 +548,6 @@ void kernfs_put(struct kernfs_node *kn)
}
EXPORT_SYMBOL_GPL(kernfs_put);
-static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
-{
- struct kernfs_node *kn;
-
- if (flags & LOOKUP_RCU)
- return -ECHILD;
-
- /* Always perform fresh lookup for negatives */
- if (d_really_is_negative(dentry))
- goto out_bad_unlocked;
-
- kn = kernfs_dentry_node(dentry);
- mutex_lock(&kernfs_mutex);
-
- /* The kernfs node has been deactivated */
- if (!kernfs_active(kn))
- goto out_bad;
-
- /* The kernfs node has been moved? */
- if (kernfs_dentry_node(dentry->d_parent) != kn->parent)
- goto out_bad;
-
- /* The kernfs node has been renamed */
- if (strcmp(dentry->d_name.name, kn->name) != 0)
- goto out_bad;
-
- /* The kernfs node has been moved to a different namespace */
- if (kn->parent && kernfs_ns_enabled(kn->parent) &&
- kernfs_info(dentry->d_sb)->ns != kn->ns)
- goto out_bad;
-
- mutex_unlock(&kernfs_mutex);
- return 1;
-out_bad:
- mutex_unlock(&kernfs_mutex);
-out_bad_unlocked:
- return 0;
-}
-
-const struct dentry_operations kernfs_dops = {
- .d_revalidate = kernfs_dop_revalidate,
-};
-
/**
* kernfs_node_from_dentry - determine kernfs_node associated with a dentry
* @dentry: the dentry in question
@@ -1073,6 +1030,49 @@ struct kernfs_node *kernfs_create_empty_dir(struct kernfs_node *parent,
return ERR_PTR(rc);
}
+static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct kernfs_node *kn;
+
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ /* Always perform fresh lookup for negatives */
+ if (d_really_is_negative(dentry))
+ goto out_bad_unlocked;
+
+ kn = kernfs_dentry_node(dentry);
+ mutex_lock(&kernfs_mutex);
+
+ /* The kernfs node has been deactivated */
+ if (!kernfs_active(kn))
+ goto out_bad;
+
+ /* The kernfs node has been moved? */
+ if (kernfs_dentry_node(dentry->d_parent) != kn->parent)
+ goto out_bad;
+
+ /* The kernfs node has been renamed */
+ if (strcmp(dentry->d_name.name, kn->name) != 0)
+ goto out_bad;
+
+ /* The kernfs node has been moved to a different namespace */
+ if (kn->parent && kernfs_ns_enabled(kn->parent) &&
+ kernfs_info(dentry->d_sb)->ns != kn->ns)
+ goto out_bad;
+
+ mutex_unlock(&kernfs_mutex);
+ return 1;
+out_bad:
+ mutex_unlock(&kernfs_mutex);
+out_bad_unlocked:
+ return 0;
+}
+
+const struct dentry_operations kernfs_dops = {
+ .d_revalidate = kernfs_dop_revalidate,
+};
+
static struct dentry *kernfs_iop_lookup(struct inode *dir,
struct dentry *dentry,
unsigned int flags)
next prev parent reply other threads:[~2021-06-15 10:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-15 10:25 [PATCH v7 0/6] kernfs: proposed locking and concurrency improvement Ian Kent
2021-06-15 10:25 ` Ian Kent [this message]
2021-06-15 15:06 ` [PATCH v7 1/6] kernfs: move revalidate to be near lookup Greg Kroah-Hartman
2021-06-15 10:26 ` [PATCH v7 2/6] kernfs: add a revision to identify directory node changes Ian Kent
2021-06-16 9:11 ` Miklos Szeredi
2021-06-15 10:26 ` [PATCH v7 3/6] kernfs: use VFS negative dentry caching Ian Kent
2021-06-16 9:12 ` Miklos Szeredi
2021-06-15 10:26 ` [PATCH v7 4/6] kernfs: switch kernfs to use an rwsem Ian Kent
2021-06-15 10:26 ` [PATCH v7 5/6] kernfs: use i_lock to protect concurrent inode updates Ian Kent
2021-06-15 10:27 ` [PATCH v7 6/6] kernfs: dont call d_splice_alias() under kernfs node lock Ian Kent
2021-06-15 10:39 ` [PATCH v7 0/6] kernfs: proposed locking and concurrency improvement Ian Kent
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