[PATCH 03/18] VFS: replace nameidata and open_flag args to lookup_open()

From: NeilBrown <[email protected]>

lookup_open is currently given "struct nameiodata" and "struct
open_flag" pointer args.  These structures are internal to VFS.  Replace
these with the individual fields that lookup_open() actually needs.
This will allow it be exported so it can be used to replace
dentry_create().

As lookup_open() can change both open_flag and mode, we keep the local
variable and create an arg with a different name which is assigned to
the local variable.

Signed-off-by: NeilBrown <[email protected]>
---
 fs/namei.c | 38 +++++++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index b00ff3f2faf7..18a43c24d7f1 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4402,12 +4402,15 @@ static struct dentry *atomic_open(const struct path *path, struct dentry *dentry
  *
  * An error code is returned on failure.
  */
-static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
-				  const struct open_flags *op)
+static struct dentry *lookup_open(const struct path *path, struct file *file,
+				  const struct qstr *last,
+				  unsigned int lookup_flags,
+				  struct filename *name,
+				  int open_flag_arg, umode_t mode_arg)
 {
 	struct delegated_inode delegated_inode = { };
 	struct mnt_idmap *idmap;
-	struct dentry *dir = nd->path.dentry;
+	struct dentry *dir = path->dentry;
 	struct inode *dir_inode = dir->d_inode;
 	int open_flag;
 	struct dentry *dentry;
@@ -4416,13 +4419,13 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 	bool got_write;
 
 retry:
-	open_flag = op->open_flag;
+	open_flag = open_flag_arg;
 	got_write = false;
-	mode = op->mode;
+	mode = mode_arg;
 	create_error = 0;
 
 	if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
-		got_write = !mnt_want_write(nd->path.mnt);
+		got_write = !mnt_want_write(path->mnt);
 		/*
 		 * do _not_ fail yet - we might not need that or fail with
 		 * a different error; let lookup_open() decide; we'll be
@@ -4440,17 +4443,17 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 	}
 
 	file->f_mode &= ~FMODE_CREATED;
-	dentry = d_lookup(dir, &nd->last);
+	dentry = d_lookup(dir, last);
 	for (;;) {
 		if (!dentry) {
-			dentry = d_alloc_parallel(dir, &nd->last);
+			dentry = d_alloc_parallel(dir, last);
 			if (IS_ERR(dentry))
 				goto out;
 		}
 		if (d_in_lookup(dentry))
 			break;
 
-		error = d_revalidate(dir_inode, &nd->last, dentry, nd->flags);
+		error = d_revalidate(dir_inode, last, dentry, lookup_flags);
 		if (likely(error > 0))
 			break;
 		if (error)
@@ -4465,7 +4468,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 	}
 
 	if (open_flag & O_CREAT)
-		audit_inode(nd->name, dir, AUDIT_INODE_PARENT);
+		audit_inode(name, dir, AUDIT_INODE_PARENT);
 
 	/*
 	 * Checking write permission is tricky, bacuse we don't know if we are
@@ -4478,13 +4481,13 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 	 */
 	if (unlikely(!got_write))
 		open_flag &= ~O_TRUNC;
-	idmap = mnt_idmap(nd->path.mnt);
+	idmap = mnt_idmap(path->mnt);
 	if (open_flag & O_CREAT) {
 		if (open_flag & O_EXCL)
 			open_flag &= ~O_TRUNC;
 		mode = vfs_prepare_mode(idmap, dir_inode, mode, mode, mode);
 		if (likely(got_write))
-			create_error = may_o_create(idmap, &nd->path,
+			create_error = may_o_create(idmap, path,
 						    dentry, mode);
 		else
 			create_error = -EROFS;
@@ -4492,9 +4495,9 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 	if (create_error)
 		open_flag &= ~O_CREAT;
 	if (dir_inode->i_op->atomic_open) {
-		if (nd->flags & LOOKUP_DIRECTORY)
+		if (lookup_flags & LOOKUP_DIRECTORY)
 			open_flag |= O_DIRECTORY;
-		dentry = atomic_open(&nd->path, dentry, file, open_flag, mode);
+		dentry = atomic_open(path, dentry, file, open_flag, mode);
 		if (unlikely(create_error) && dentry == ERR_PTR(-ENOENT))
 			dentry = ERR_PTR(create_error);
 		goto out;
@@ -4502,7 +4505,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 
 	if (d_in_lookup(dentry)) {
 		struct dentry *res = dir_inode->i_op->lookup(dir_inode, dentry,
-							     nd->flags);
+							     lookup_flags);
 		d_lookup_done(dentry);
 		if (unlikely(res)) {
 			if (IS_ERR(res)) {
@@ -4550,7 +4553,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 		inode_unlock_shared(dir_inode);
 
 	if (got_write)
-		mnt_drop_write(nd->path.mnt);
+		mnt_drop_write(path->mnt);
 
 	if (is_delegated(&delegated_inode)) {
 		/* Must have come through out_dput */
@@ -4637,7 +4640,8 @@ static const char *open_last_lookups(struct nameidata *nd,
 		}
 	}
 
-	dentry = lookup_open(nd, file, op);
+	dentry = lookup_open(&nd->path, file, &nd->last,
+			     nd->flags, nd->name, op->open_flag, op->mode);
 	if (IS_ERR(dentry))
 		return ERR_CAST(dentry);
 
-- 
2.50.0.107.gf914562f5916.dirty