[PATCH v4 52/54] convert securityfs

[Al Viro <viro@zeniv.linux.org.uk>]

securityfs uses simple_recursive_removal(), but does not bother to mark
dentries persistent.  This is the only place where it still happens; get
rid of that irregularity.

* use simple_{start,done}_creating() and d_make_persitent(); kill_litter_super()
use was already gone, since we empty the filesystem instance before it gets
shut down.

Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 security/inode.c | 33 ++++++++++++---------------------
 1 file changed, 12 insertions(+), 21 deletions(-)

diff --git a/security/inode.c b/security/inode.c
index bf7b5e2e6955..73df5db7f831 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -127,24 +127,19 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
 		parent = mount->mnt_root;
 	}
 
-	dir = d_inode(parent);
-
-	inode_lock(dir);
-	dentry = lookup_noperm(&QSTR(name), parent);
-	if (IS_ERR(dentry))
+	inode = new_inode(parent->d_sb);
+	if (unlikely(!inode)) {
+		dentry = ERR_PTR(-ENOMEM);
 		goto out;
-
-	if (d_really_is_positive(dentry)) {
-		error = -EEXIST;
-		goto out1;
 	}
 
-	inode = new_inode(dir->i_sb);
-	if (!inode) {
-		error = -ENOMEM;
-		goto out1;
-	}
+	dir = d_inode(parent);
 
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry)) {
+		iput(inode);
+		goto out;
+	}
 	inode->i_ino = get_next_ino();
 	inode->i_mode = mode;
 	simple_inode_init_ts(inode);
@@ -160,15 +155,11 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
 	} else {
 		inode->i_fop = fops;
 	}
-	d_instantiate(dentry, inode);
-	inode_unlock(dir);
-	return dentry;
+	d_make_persistent(dentry, inode);
+	simple_done_creating(dentry);
+	return dentry; // borrowed
 
-out1:
-	dput(dentry);
-	dentry = ERR_PTR(error);
 out:
-	inode_unlock(dir);
 	if (pinned)
 		simple_release_fs(&mount, &mount_count);
 	return dentry;
-- 
2.47.3