linux-next: build failure after merge of the vfs-brauner tree

Hi all,

After merging the vfs-brauner tree, today's linux-next build (x86_64 allmodconfig) failed like this:

/tmp/next/build/fs/smb/client/cifsfs.c:1258:18: error: incompatible function pointer types initializing 'int (*)(const struct mnt_idmap *, struct dentry *, struct file_kattr *)' with an expression of type 'int (struct mnt_idmap *, struct dentry *, struct file_kattr *)' [-Wincompatible-function-pointer-types]
1258 | .fileattr_set = cifs_fileattr_set,

      |                         ^~~~~~~~~~~~~~~~~
/tmp/next/build/fs/smb/client/cifsfs.c:1270:18: error: incompatible function pointer types initializing 'int (*)(const struct mnt_idmap *, struct dentry *, struct file_kattr *)' with an expression of type 'int (struct mnt_idmap *, struct dentry *, struct file_kattr *)' [-Wincompatible-function-pointer-types]
 1270 |         .fileattr_set = cifs_fileattr_set,
      |                         ^~~~~~~~~~~~~~~~~

2 errors generated.
make[6]: *** [/tmp/next/build/scripts/Makefile.build:290: fs/smb/client/cifsfs.o] Error 1
make[6]: *** Waiting for unfinished jobs....
make[5]: *** [/tmp/next/build/scripts/Makefile.build:551: fs/smb/client] Error 2
make[5]: *** Waiting for unfinished jobs....
/tmp/next/build/fs/ntfs/namei.c:793:40: error: passing 'const struct mnt_idmap *' to parameter of type 'struct mnt_idmap *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
793 | stream_vi = ntfs_create_named_stream(idmap, dir, base_name,
| ^~~~~
/tmp/next/build/fs/ntfs/stream.h:35:58: note: passing argument to parameter 'idmap' here
35 | struct inode *ntfs_create_named_stream(struct mnt_idmap *idmap,
| ^
1 error generated.

Caused by the constification series for mnt_idmap interacting with:

2de2cdd9cc08f (ntfs: add pathname access for named streams) 121e0c35720b2 (smb: client: implement fileattr_set for compression flags)

from the cifs and ntfs trees. I have applied the fixup below and can carry as needed.

From 6b75090639b332f5fa52a558edbba295d8bb42fc Mon Sep 17 00:00:00 2001
From: Mark Brown <[email protected]>
Date: Mon, 12 Oct 2026 13:55:24 +0100
Subject: [PATCH] cifs: Fix semantic conflict with const mnt_idmap

/tmp/next/build/fs/smb/client/cifsfs.c:1258:18: error: incompatible function pointer types initializing 'int (*)(const struct mnt_idmap *, struct dentry *, struct file_kattr *)' with an expression of type 'int (struct mnt_idmap *, struct dentry *, struct file_kattr *)' [-Wincompatible-function-pointer-types]
1258 | .fileattr_set = cifs_fileattr_set,

      |                         ^~~~~~~~~~~~~~~~~
/tmp/next/build/fs/smb/client/cifsfs.c:1270:18: error: incompatible function pointer types initializing 'int (*)(const struct mnt_idmap *, struct dentry *, struct file_kattr *)' with an expression of type 'int (struct mnt_idmap *, struct dentry *, struct file_kattr *)' [-Wincompatible-function-pointer-types]
 1270 |         .fileattr_set = cifs_fileattr_set,
      |                         ^~~~~~~~~~~~~~~~~

2 errors generated.

Signed-off-by Mark Brown <[email protected]>

---
 fs/ntfs/named_stream.c | 6 +++---
 fs/ntfs/stream.h       | 2 +-
 fs/smb/client/cifsfs.h | 2 +-
 fs/smb/client/ioctl.c  | 2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)

fs/ntfs/named_stream.c +3 -3

index d74bebf90966b..95a3c05f98211 100644
@@ -553,7 +553,7 @@ int ntfs_stream_path_names(struct ntfs_volume *vol,
  *
  * Return: Referenced stream inode on success, or ERR_PTR() on failure.
  */
-struct inode *ntfs_create_named_stream(struct mnt_idmap *idmap,
+struct inode *ntfs_create_named_stream(const struct mnt_idmap *idmap,
                struct inode *dir, __le16 *base_name, int base_len,
                __le16 *stream_name, int stream_len)
 {

@@ -988,13 +988,13 @@ static ssize_t ntfs_stream_listxattr(struct dentry *dentry, char *buffer,
 }
 
 #ifdef CONFIG_NTFS_FS_POSIX_ACL
-static struct posix_acl *ntfs_stream_get_acl(struct mnt_idmap *idmap,
+static struct posix_acl *ntfs_stream_get_acl(const struct mnt_idmap *idmap,
                struct dentry *dentry, int type)
 {
        return ERR_PTR(-EOPNOTSUPP);
 }
 
-static int ntfs_stream_set_acl(struct mnt_idmap *idmap,
+static int ntfs_stream_set_acl(const struct mnt_idmap *idmap,
                struct dentry *dentry, struct posix_acl *acl, int type)
 {
        return -EOPNOTSUPP;

fs/ntfs/stream.h +1 -1

index 5cbf6e8f6b681..76b6c9cca5cc0 100644
@@ -32,7 +32,7 @@ struct inode *ntfs_stream_lookup_inode_by_name(struct inode *dir,
                __le16 *name, int name_len);
 struct dentry *ntfs_lookup_stream(struct inode *dir, struct dentry *dentry,
                const struct ntfs_stream_path *path);
-struct inode *ntfs_create_named_stream(struct mnt_idmap *idmap,
+struct inode *ntfs_create_named_stream(const struct mnt_idmap *idmap,
                struct inode *dir, __le16 *base_name, int base_len,
                __le16 *stream_name, int stream_len);
 int ntfs_unlink_named_stream(struct inode *dir, struct dentry *dentry);

fs/smb/client/cifsfs.h +1 -1

index 7600467babb67..e54d3798eb2f7 100644
@@ -91,7 +91,7 @@ extern const struct inode_operations cifs_namespace_inode_operations;
 
 struct file_kattr;
 int cifs_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
-int cifs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
+int cifs_fileattr_set(const struct mnt_idmap *idmap, struct dentry *dentry,
                      struct file_kattr *fa);
 
 

fs/smb/client/ioctl.c +1 -2

index af4664f5b1202..bb8808289a468 100644
@@ -181,7 +181,7 @@ static int cifs_set_compression(unsigned int xid, struct dentry *dentry,
                                            compression_state);
 }
 
-int cifs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
+int cifs_fileattr_set(const struct mnt_idmap *idmap, struct dentry *dentry,
                      struct file_kattr *fa)
 {
        struct cifs_sb_info *cifs_sb = CIFS_SB(dentry);
--

2.47.3

Mark Brown <[email protected]>, 12 Eki 2026 Pzt, 16:50 tarihinde şunu yazdı:

Quoted 2 lines

Hi all,

Hi Mark,

i noticed Namjae Jeon's commit (2de2cdd9cc08, ntfs: add pathname access for named streams) is currently present in fs-next and your reported build failure appears to result from this commit interacting with VFS changes that make mnt_idmap const in the ->setattr() and ->getattr() callbacks, and i think fs-next before changes are integrated into linux-next

i compiled linux-next tree but couldnt reproduce the build failure.