Re: [RFC PATCH 07/20] famfs: Add include/linux/famfs_ioctl.h

John Groves
2024-02-24T23:32:37Z

On 24/02/23 07:27PM, Randy Dunlap wrote:
> Hi John,
>
> On 2/23/24 18:23, John Groves wrote:
> >>> +
> >>> +#define FAMFSIOC_MAGIC 'u'
> >> This 'u' value should be documented in
> >> Documentation/userspace-api/ioctl/ioctl-number.rst.
> >>
> >> and if possible, you might want to use values like 0x5x or 0x8x
> >> that don't conflict with the ioctl numbers that are already used
> >> in the 'u' space.
> > Will do. I was trying to be too clever there, invoking "mu" for
> > micron.
>
> I might have been unclear about this one.
> It's OK to use 'u' but the values 1-4 below conflict in the 'u' space:
>
> 'u' 00-1F linux/smb_fs.h gone
> 'u' 20-3F linux/uvcvideo.h USB video class host driver
> 'u' 40-4f linux/udmabuf.h
>
> so if you could use
> 'u' 50-5f
> or
> 'u' 80-8f
>
> then those conflicts wouldn't be there.
> HTH.
>
> >>> +
> >>> +/* famfs file ioctl opcodes */
> >>> +#define FAMFSIOC_MAP_CREATE _IOW(FAMFSIOC_MAGIC, 1, struct famfs_ioc_map)
> >>> +#define FAMFSIOC_MAP_GET _IOR(FAMFSIOC_MAGIC, 2, struct famfs_ioc_map)
> >>> +#define FAMFSIOC_MAP_GETEXT _IOR(FAMFSIOC_MAGIC, 3, struct famfs_extent)
> >>> +#define FAMFSIOC_NOP _IO(FAMFSIOC_MAGIC, 4)
>
> --
> #Randy

Thanks Randy; I think I'm the one that didn't read carefully enough.

Does this look right?

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 457e16f06e04..44a44809657b 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -288,6 +288,7 @@ Code Seq# Include File Comments
'u' 00-1F linux/smb_fs.h gone
'u' 20-3F linux/uvcvideo.h USB video class host driver
'u' 40-4f linux/udmabuf.h userspace dma-buf misc device
+'u' 50-5F linux/famfs_ioctl.h famfs shared memory file system
'v' 00-1F linux/ext2_fs.h conflict!
'v' 00-1F linux/fs.h conflict!
'v' 00-0F linux/sonypi.h conflict!
diff --git a/include/uapi/linux/famfs_ioctl.h b/include/uapi/linux/famfs_ioctl.h
index 6b3e6452d02f..57521898ed57 100644
--- a/include/uapi/linux/famfs_ioctl.h
+++ b/include/uapi/linux/famfs_ioctl.h
@@ -48,9 +48,9 @@ struct famfs_ioc_map {
#define FAMFSIOC_MAGIC 'u'

/* famfs file ioctl opcodes */
-#define FAMFSIOC_MAP_CREATE _IOW(FAMFSIOC_MAGIC, 1, struct famfs_ioc_map)
-#define FAMFSIOC_MAP_GET _IOR(FAMFSIOC_MAGIC, 2, struct famfs_ioc_map)
-#define FAMFSIOC_MAP_GETEXT _IOR(FAMFSIOC_MAGIC, 3, struct famfs_extent)
-#define FAMFSIOC_NOP _IO(FAMFSIOC_MAGIC, 4)
+#define FAMFSIOC_MAP_CREATE _IOW(FAMFSIOC_MAGIC, 0x50, struct famfs_ioc_map)
+#define FAMFSIOC_MAP_GET _IOR(FAMFSIOC_MAGIC, 0x51, struct famfs_ioc_map)
+#define FAMFSIOC_MAP_GETEXT _IOR(FAMFSIOC_MAGIC, 0x52, struct famfs_extent)
+#define FAMFSIOC_NOP _IO(FAMFSIOC_MAGIC, 0x53)

Thank you!
John