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Message-ID: <20251029234353.1321957-15-neilb@ownmail.net>
Date: Thu, 30 Oct 2025 10:31:14 +1100
From: NeilBrown <neilb@...mail.net>
To: "Alexander Viro" <viro@...iv.linux.org.uk>,
"Christian Brauner" <brauner@...nel.org>,
"Amir Goldstein" <amir73il@...il.com>
Cc: "Jan Kara" <jack@...e.cz>, linux-fsdevel@...r.kernel.org,
Jeff Layton <jlayton@...nel.org>, Chris Mason <clm@...com>,
David Sterba <dsterba@...e.com>, David Howells <dhowells@...hat.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"Rafael J. Wysocki" <rafael@...nel.org>,
Danilo Krummrich <dakr@...nel.org>, Tyler Hicks <code@...icks.com>,
Miklos Szeredi <miklos@...redi.hu>, Chuck Lever <chuck.lever@...cle.com>,
Olga Kornievskaia <okorniev@...hat.com>, Dai Ngo <Dai.Ngo@...cle.com>,
Namjae Jeon <linkinjeon@...nel.org>, Steve French <smfrench@...il.com>,
Sergey Senozhatsky <senozhatsky@...omium.org>,
Carlos Maiolino <cem@...nel.org>,
John Johansen <john.johansen@...onical.com>,
Paul Moore <paul@...l-moore.com>, James Morris <jmorris@...ei.org>,
"Serge E. Hallyn" <serge@...lyn.com>,
Stephen Smalley <stephen.smalley.work@...il.com>,
Ondrej Mosnacek <omosnace@...hat.com>, Mateusz Guzik <mjguzik@...il.com>,
Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
Stefan Berger <stefanb@...ux.ibm.com>,
"Darrick J. Wong" <djwong@...nel.org>, linux-kernel@...r.kernel.org,
netfs@...ts.linux.dev, ecryptfs@...r.kernel.org,
linux-nfs@...r.kernel.org, linux-unionfs@...r.kernel.org,
linux-cifs@...r.kernel.org, linux-xfs@...r.kernel.org,
apparmor@...ts.ubuntu.com, linux-security-module@...r.kernel.org,
selinux@...r.kernel.org
Subject: [PATCH v4 14/14] VFS: introduce end_creating_keep()
From: NeilBrown <neil@...wn.name>
Occasionally the caller of end_creating() wants to keep using the dentry.
Rather then requiring them to dget() the dentry (when not an error)
before calling end_creating(), provide end_creating_keep() which does
this.
cachefiles and overlayfs make use of this.
Reviewed-by: Amir Goldstein <amir73il@...il.com>
Signed-off-by: NeilBrown <neil@...wn.name>
---
fs/cachefiles/namei.c | 3 +--
fs/overlayfs/dir.c | 8 ++------
fs/overlayfs/super.c | 11 +++--------
include/linux/namei.h | 22 ++++++++++++++++++++++
4 files changed, 28 insertions(+), 16 deletions(-)
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index c417ba4bcec3..4c72af174540 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -155,8 +155,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
/* Tell rmdir() it's not allowed to delete the subdir */
inode_lock(d_inode(subdir));
- dget(subdir);
- end_creating(subdir);
+ end_creating_keep(subdir);
if (!__cachefiles_mark_inode_in_use(NULL, d_inode(subdir))) {
pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n",
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 10e732360ace..8faab04dc79f 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -252,10 +252,7 @@ struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir,
if (IS_ERR(ret))
return ret;
ret = ovl_create_real(ofs, workdir, ret, attr);
- if (!IS_ERR(ret))
- dget(ret);
- end_creating(ret);
- return ret;
+ return end_creating_keep(ret);
}
static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper,
@@ -365,8 +362,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
if (IS_ERR(newdentry))
return PTR_ERR(newdentry);
- dget(newdentry);
- end_creating(newdentry);
+ end_creating_keep(newdentry);
if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry) &&
!ovl_allow_offline_changes(ofs)) {
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 3acda985c8a3..7b8fc1cab6eb 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -319,8 +319,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
};
if (work->d_inode) {
- dget(work);
- end_creating(work);
+ end_creating_keep(work);
if (persist)
return work;
err = -EEXIST;
@@ -336,9 +335,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
}
work = ovl_do_mkdir(ofs, dir, work, attr.ia_mode);
- if (!IS_ERR(work))
- dget(work);
- end_creating(work);
+ end_creating_keep(work);
err = PTR_ERR(work);
if (IS_ERR(work))
goto out_err;
@@ -630,9 +627,7 @@ static struct dentry *ovl_lookup_or_create(struct ovl_fs *ofs,
if (!child->d_inode)
child = ovl_create_real(ofs, parent, child,
OVL_CATTR(mode));
- if (!IS_ERR(child))
- dget(child);
- end_creating(child);
+ end_creating_keep(child);
}
dput(parent);
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 0ef73d739a31..3d82c6a19197 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -125,6 +125,28 @@ static inline void end_creating(struct dentry *child)
end_dirop(child);
}
+/* end_creating_keep - finish action started with start_creating() and return result
+ * @child: dentry returned by start_creating() or vfs_mkdir()
+ *
+ * Unlock and return the child. This can be called after
+ * start_creating() whether that function succeeded or not,
+ * but it is not needed on failure.
+ *
+ * If vfs_mkdir() was called then the value returned from that function
+ * should be given for @child rather than the original dentry, as vfs_mkdir()
+ * may have provided a new dentry.
+ *
+ * Returns: @child, which may be a dentry or an error.
+ *
+ */
+static inline struct dentry *end_creating_keep(struct dentry *child)
+{
+ if (!IS_ERR(child))
+ dget(child);
+ end_dirop(child);
+ return child;
+}
+
/**
* end_removing - finish action started with start_removing
* @child: dentry returned by start_removing()
--
2.50.0.107.gf914562f5916.dirty
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