[PATCH v6 08/12] vfs: change ->create/->mkdir operations unavailable errno

[Jori Koolstra]

Currently filesystems return -EACCES for missing ->create and -EPERM for
missing ->mkdir in vfs_create/vfs_mkdir. Instead of duplicating these
dubious and inconsistent error codes to lookup_open(), change all to
-EOPNOTSUPP.

Signed-off-by: Jori Koolstra <jkoolstra@xxxxxxxxx>
---
 fs/namei.c                       | 14 +++++---------
 include/uapi/asm-generic/errno.h |  2 +-
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 6ff0a3c04f02..f31046f8b3ba 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4224,7 +4224,7 @@ int vfs_create(struct mnt_idmap *idmap, struct dentry *dentry, umode_t mode,
 		return error;
 
 	if (!dir->i_op->create)
-		return -EACCES;	/* shouldn't it be ENOSYS? */
+		return -EOPNOTSUPP;
 
 	mode = vfs_prepare_mode(idmap, dir, mode, S_IALLUGO, S_IFREG);
 	error = security_inode_create(dir, dentry, mode);
@@ -4646,13 +4646,9 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
 		goto out_dput;
 	}
 
-	/* mimic operation missing errnos of vfs_mkdir/vfs_create */
-	if (create_dir && !dir_inode->i_op->mkdir) {
-		error = -EPERM;
-		goto out_dput;
-	}
-	if (!create_dir && !dir_inode->i_op->create) {
-		error = -EACCES;
+	if ((create_dir && !dir_inode->i_op->mkdir)
+		|| (!create_dir && !dir_inode->i_op->create)) {
+		error = -EOPNOTSUPP;
 		goto out_dput;
 	}
 
@@ -5501,7 +5497,7 @@ struct dentry *vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	if (error)
 		goto err;
 
-	error = -EPERM;
+	error = -EOPNOTSUPP;
 	if (!dir->i_op->mkdir)
 		goto err;
 
diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/errno.h
index bd78e69e0a43..c84ebf89c8b6 100644
--- a/include/uapi/asm-generic/errno.h
+++ b/include/uapi/asm-generic/errno.h
@@ -76,7 +76,7 @@
 #define	ENOPROTOOPT	92	/* Protocol not available */
 #define	EPROTONOSUPPORT	93	/* Protocol not supported */
 #define	ESOCKTNOSUPPORT	94	/* Socket type not supported */
-#define	EOPNOTSUPP	95	/* Operation not supported on transport endpoint */
+#define	EOPNOTSUPP	95	/* Operation not supported */
 #define	EPFNOSUPPORT	96	/* Protocol family not supported */
 #define	EAFNOSUPPORT	97	/* Address family not supported by protocol */
 #define	EADDRINUSE	98	/* Address already in use */
-- 
2.55.0