[PATCH 06/12] vfs: lookup_open(): move i_op->create check to before try_break_deleg()

[Jori Koolstra]

The i_op->create check in lookup_open() takes place after the
try_break_deleg() call. This does not match the order when doing a
regular file create via mknod(2). There the call order is:

	filename_mknodat()
	vfs_create()
	i_op->create check
	try_break_deleg()

Move the i_op->create check to before try_break_deleg() in
lookup_open().

Signed-off-by: Jori Koolstra <jkoolstra@xxxxxxxxx>
---
 fs/namei.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index e21f23502e8d..15bf28b85a4e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4341,6 +4341,7 @@ static int may_o_create(struct mnt_idmap *idmap,
 			const struct path *dir, struct dentry *dentry,
 			umode_t mode)
 {
+
 	int error = security_path_mknod(dir, dentry, mode, 0);
 	if (error)
 		return error;
@@ -4528,16 +4529,17 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 
 	/* Negative dentry, just create the file */
 	if (!dentry->d_inode && (open_flag & O_CREAT)) {
-		/* but break the directory lease first! */
-		error = try_break_deleg(dir_inode, delegated_inode);
-		if (error)
-			goto out_dput;
 
 		if (!dir_inode->i_op->create) {
 			error = -EACCES;
 			goto out_dput;
 		}
 
+		/* but break the directory lease first! */
+		error = try_break_deleg(dir_inode, delegated_inode);
+		if (error)
+			goto out_dput;
+
 		error = dir_inode->i_op->create(idmap, dir_inode, dentry,
 						mode, open_flag & O_EXCL);
 		if (error)
-- 
2.54.0