linux-kernel - [PATCH v2 7/7] tracefs: switch to simplefs inode creation API

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Message-Id: <20200421135741.30657-5-eesposit@redhat.com>
Date:   Tue, 21 Apr 2020 15:57:41 +0200
From:   Emanuele Giuseppe Esposito <eesposit@...hat.com>
To:     linux-fsdevel@...r.kernel.org
Cc:     Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Frederic Barrat <fbarrat@...ux.ibm.com>,
        Andrew Donnellan <ajd@...ux.ibm.com>,
        Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Manoj N. Kumar" <manoj@...ux.ibm.com>,
        "Matthew R. Ochs" <mrochs@...ux.ibm.com>,
        Uma Krishnan <ukrishn@...ux.ibm.com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Joel Becker <jlbec@...lplan.org>,
        Christoph Hellwig <hch@....de>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        John Johansen <john.johansen@...onical.com>,
        James Morris <jmorris@...ei.org>,
        "Serge E. Hallyn" <serge@...lyn.com>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org, linux-scsi@...r.kernel.org,
        linux-security-module@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Emanuele Giuseppe Esposito <eesposit@...hat.com>
Subject: [PATCH v2 7/7] tracefs: switch to simplefs inode creation API

There is no semantic change intended; the code in the libfs.c
functions in fact was derived from debugfs and tracefs code.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@...hat.com>
---
 fs/tracefs/inode.c | 86 ++++------------------------------------------
 1 file changed, 7 insertions(+), 79 deletions(-)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 370eb38ff1ad..bceaa4f45da2 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -308,57 +308,6 @@ static struct file_system_type trace_fs_type = {
 };
 MODULE_ALIAS_FS("tracefs");
 
-static struct dentry *start_creating(const char *name, struct dentry *parent)
-{
-	struct dentry *dentry;
-	int error;
-
-	pr_debug("tracefs: creating file '%s'\n",name);
-
-	error = simple_pin_fs(&tracefs, &trace_fs_type);
-	if (error)
-		return ERR_PTR(error);
-
-	/* If the parent is not specified, we create it in the root.
-	 * We need the root dentry to do this, which is in the super
-	 * block. A pointer to that is in the struct vfsmount that we
-	 * have around.
-	 */
-	if (!parent)
-		parent = tracefs.mount->mnt_root;
-
-	inode_lock(parent->d_inode);
-	if (unlikely(IS_DEADDIR(parent->d_inode)))
-		dentry = ERR_PTR(-ENOENT);
-	else
-		dentry = lookup_one_len(name, parent, strlen(name));
-	if (!IS_ERR(dentry) && dentry->d_inode) {
-		dput(dentry);
-		dentry = ERR_PTR(-EEXIST);
-	}
-
-	if (IS_ERR(dentry)) {
-		inode_unlock(parent->d_inode);
-		simple_release_fs(&tracefs);
-	}
-
-	return dentry;
-}
-
-static struct dentry *failed_creating(struct dentry *dentry)
-{
-	inode_unlock(dentry->d_parent->d_inode);
-	dput(dentry);
-	simple_release_fs(&tracefs);
-	return NULL;
-}
-
-static struct dentry *end_creating(struct dentry *dentry)
-{
-	inode_unlock(dentry->d_parent->d_inode);
-	return dentry;
-}
-
 /**
  * tracefs_create_file - create a file in the tracefs filesystem
  * @name: a pointer to a string containing the name of the file to create.
@@ -395,49 +344,28 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
 	if (security_locked_down(LOCKDOWN_TRACEFS))
 		return NULL;
 
-	if (!(mode & S_IFMT))
-		mode |= S_IFREG;
-	BUG_ON(!S_ISREG(mode));
-	dentry = start_creating(name, parent);
-
+	dentry = simplefs_create_file(&tracefs, &trace_fs_type,
+				      name, mode, parent, data, &inode);
 	if (IS_ERR(dentry))
 		return NULL;
 
-	inode = tracefs_get_inode(dentry->d_sb);
-	if (unlikely(!inode))
-		return failed_creating(dentry);
-
-	inode->i_mode = mode;
 	inode->i_fop = fops ? fops : &tracefs_file_operations;
-	inode->i_private = data;
-	d_instantiate(dentry, inode);
-	fsnotify_create(dentry->d_parent->d_inode, dentry);
-	return end_creating(dentry);
+	return simplefs_finish_dentry(dentry, inode);
 }
 
 static struct dentry *__create_dir(const char *name, struct dentry *parent,
 				   const struct inode_operations *ops)
 {
-	struct dentry *dentry = start_creating(name, parent);
+	struct dentry *dentry;
 	struct inode *inode;
 
+	dentry = simplefs_create_dir(&tracefs, &trace_fs_type,
+				     name, 0755, parent, &inode);
 	if (IS_ERR(dentry))
 		return NULL;
 
-	inode = tracefs_get_inode(dentry->d_sb);
-	if (unlikely(!inode))
-		return failed_creating(dentry);
-
-	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
 	inode->i_op = ops;
-	inode->i_fop = &simple_dir_operations;
-
-	/* directory inodes start off with i_nlink == 2 (for "." entry) */
-	inc_nlink(inode);
-	d_instantiate(dentry, inode);
-	inc_nlink(dentry->d_parent->d_inode);
-	fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
-	return end_creating(dentry);
+	return simplefs_finish_dentry(dentry, inode);
 }
 
 /**
-- 
2.25.2