On Mon, 27 Apr 2026 at 12:47, Jan Kara [off-list ref] wrote:

On Fri 24-04-26 21:53:14, Chuck Lever wrote:

quoted

From: Chuck Lever <chuck.lever@oracle.com>

Upper layers such as NFSD need a way to query whether a
filesystem handles filenames in a case-sensitive manner so
they can provide correct semantics to remote clients. Without
this information, NFS exports of ISO 9660 filesystems cannot
advertise their filename case behavior.

Implement isofs_fileattr_get() to report ISO 9660 case handling
behavior via the FS_XFLAG_CASEFOLD flag. The 'check=r' (relaxed)
mount option enables case-insensitive lookups, and this setting
determines the value reported. By default, Joliet extensions
operate in relaxed mode while plain ISO 9660 uses strict
(case-sensitive) mode. All ISO 9660 variants are case-preserving,
meaning filenames are stored exactly as they appear on the disc.

Case handling is a superblock-wide property, so the callback
must report the same value for every inode type. Regular files
previously had no inode_operations; introduce
isofs_file_inode_operations to carry the callback. Symlinks
previously shared page_symlink_inode_operations; introduce
isofs_symlink_inode_operations, which wires page_get_link
alongside the callback, so that fileattr queries on a symlink
reach the isofs implementation instead of returning
-ENOIOCTLCMD. The flag is set in both fa->fsx_xflags and
fa->flags so FS_IOC_FSGETXATTR and FS_IOC_GETFLAGS agree.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Roland Mainz <redacted>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

...

quoted

@@ -281,6 +293,18 @@ const struct file_operations isofs_dir_operations =
 const struct inode_operations isofs_dir_inode_operations =
 {
      .lookup = isofs_lookup,
+     .fileattr_get = isofs_fileattr_get,
+};
+
+const struct inode_operations isofs_file_inode_operations =
+{
+     .fileattr_get = isofs_fileattr_get,
+};
+
+const struct inode_operations isofs_symlink_inode_operations =
+{
+     .get_link = page_get_link,
+     .fileattr_get = isofs_fileattr_get,
 };

Hum, I thought casefolding is a directory attribute. At least I don't see
a big point in reporting it for regular files or symlinks (and then why not
report it for device nodes or named pipes?). So why did you decide for this
change?

Where do you see this being a per-directory attribute in
https://web.archive.org/web/20170404043745/http://www.ymi.com/ymi/sites/default/files/pdf/Rockridge.pdf

Lionel