diff mbox series

[v6,7/7] kernfs: dont call d_splice_alias() under kernfs node lock

Message ID 162322874509.361452.3143376113190093370.stgit@web.messagingengine.com (mailing list archive)
State New
Headers show
Series kernfs: proposed locking and concurrency improvement | expand

Commit Message

Ian Kent June 9, 2021, 8:52 a.m. UTC
The call to d_splice_alias() in kernfs_iop_lookup() doesn't depend on
any kernfs node so there's no reason to hold the kernfs node lock when
calling it.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/kernfs/dir.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

Comments

Miklos Szeredi June 11, 2021, 1:14 p.m. UTC | #1
On Wed, 9 Jun 2021 at 10:52, Ian Kent <raven@themaw.net> wrote:
>
> The call to d_splice_alias() in kernfs_iop_lookup() doesn't depend on
> any kernfs node so there's no reason to hold the kernfs node lock when
> calling it.
>
> Signed-off-by: Ian Kent <raven@themaw.net>

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
diff mbox series

Patch

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 195561c08439a..a5820a8c139a2 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1097,7 +1097,6 @@  static struct dentry *kernfs_iop_lookup(struct inode *dir,
 					struct dentry *dentry,
 					unsigned int flags)
 {
-	struct dentry *ret;
 	struct kernfs_node *parent = dir->i_private;
 	struct kernfs_node *kn;
 	struct inode *inode = NULL;
@@ -1117,11 +1116,10 @@  static struct dentry *kernfs_iop_lookup(struct inode *dir,
 	/* Needed only for negative dentry validation */
 	if (!inode)
 		kernfs_set_rev(parent, dentry);
-	/* instantiate and hash (possibly negative) dentry */
-	ret = d_splice_alias(inode, dentry);
 	up_read(&kernfs_rwsem);
 
-	return ret;
+	/* instantiate and hash (possibly negative) dentry */
+	return d_splice_alias(inode, dentry);
 }
 
 static int kernfs_iop_mkdir(struct user_namespace *mnt_userns,