fs/ntfs3: Redesign ntfs_create_inode to return error code instead of inode

As Al Viro correctly pointed out, there is no need to return
the whole structure to check the error.
https://lore.kernel.org/ntfs3/20240322023515.GK538574@ZenIV/Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/inode.c

@@ -1216,11 +1216,10 @@ ntfs_create_reparse_buffer(struct ntfs_sb_info *sbi, const char *symname,
  *
  * NOTE: if fnd != NULL (ntfs_atomic_open) then @dir is locked
  */
-struct inode *ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
-				struct dentry *dentry,
-				const struct cpu_str *uni, umode_t mode,
-				dev_t dev, const char *symname, u32 size,
-				struct ntfs_fnd *fnd)
+int ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
+		      struct dentry *dentry, const struct cpu_str *uni,
+		      umode_t mode, dev_t dev, const char *symname, u32 size,
+		      struct ntfs_fnd *fnd)
 {
 	int err;
 	struct super_block *sb = dir->i_sb;
@@ -1245,6 +1244,9 @@ struct inode *ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
 	struct REPARSE_DATA_BUFFER *rp = NULL;
 	bool rp_inserted = false;
 
+	/* New file will be resident or non resident. */
+	const bool new_file_resident = 1;
+
 	if (!fnd)
 		ni_lock_dir(dir_ni);
 
@@ -1484,7 +1486,7 @@ struct inode *ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
 		attr->size = cpu_to_le32(SIZEOF_RESIDENT);
 		attr->name_off = SIZEOF_RESIDENT_LE;
 		attr->res.data_off = SIZEOF_RESIDENT_LE;
-	} else if (S_ISREG(mode)) {
+	} else if (!new_file_resident && S_ISREG(mode)) {
 		/*
 		 * Regular file. Create empty non resident data attribute.
 		 */
@@ -1721,12 +1723,10 @@ struct inode *ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
 	if (!fnd)
 		ni_unlock(dir_ni);
 
-	if (err)
-		return ERR_PTR(err);
-
-	unlock_new_inode(inode);
+	if (!err)
+		unlock_new_inode(inode);
 
-	return inode;
+	return err;
 }
 
 int ntfs_link_inode(struct inode *inode, struct dentry *dentry)

fs/ntfs3/namei.c

@@ -107,12 +107,8 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
 static int ntfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
-	struct inode *inode;
-
-	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFREG | mode, 0,
-				  NULL, 0, NULL);
-
-	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+	return ntfs_create_inode(idmap, dir, dentry, NULL, S_IFREG | mode, 0,
+				 NULL, 0, NULL);
 }
 
 /*
@@ -123,12 +119,8 @@ static int ntfs_create(struct mnt_idmap *idmap, struct inode *dir,
 static int ntfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
-	struct inode *inode;
-
-	inode = ntfs_create_inode(idmap, dir, dentry, NULL, mode, rdev, NULL, 0,
-				  NULL);
-
-	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+	return ntfs_create_inode(idmap, dir, dentry, NULL, mode, rdev, NULL, 0,
+				 NULL);
 }
 
 /*
@@ -200,15 +192,12 @@ static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	u32 size = strlen(symname);
-	struct inode *inode;
 
 	if (unlikely(ntfs3_forced_shutdown(dir->i_sb)))
 		return -EIO;
 
-	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFLNK | 0777, 0,
-				  symname, size, NULL);
-
-	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+	return ntfs_create_inode(idmap, dir, dentry, NULL, S_IFLNK | 0777, 0,
+				 symname, size, NULL);
 }
 
 /*
@@ -217,12 +206,8 @@ static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 static int ntfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
-	struct inode *inode;
-
-	inode = ntfs_create_inode(idmap, dir, dentry, NULL, S_IFDIR | mode, 0,
-				  NULL, 0, NULL);
-
-	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+	return ntfs_create_inode(idmap, dir, dentry, NULL, S_IFDIR | mode, 0,
+				 NULL, 0, NULL);
 }
 
 /*

fs/ntfs3/ntfs_fs.h

@@ -714,11 +714,10 @@ int ntfs_sync_inode(struct inode *inode);
 int ntfs_flush_inodes(struct super_block *sb, struct inode *i1,
 		      struct inode *i2);
 int inode_write_data(struct inode *inode, const void *data, size_t bytes);
-struct inode *ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
-				struct dentry *dentry,
-				const struct cpu_str *uni, umode_t mode,
-				dev_t dev, const char *symname, u32 size,
-				struct ntfs_fnd *fnd);
+int ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
+		      struct dentry *dentry, const struct cpu_str *uni,
+		      umode_t mode, dev_t dev, const char *symname, u32 size,
+		      struct ntfs_fnd *fnd);
 int ntfs_link_inode(struct inode *inode, struct dentry *dentry);
 int ntfs_unlink_inode(struct inode *dir, const struct dentry *dentry);
 void ntfs_evict_inode(struct inode *inode);