Re: [PATCH 1/6] ipc: Move mqueue fs magic to uapi magic header
From: Günther Noack <gnoack@google.com>
Date: 2026-07-22 12:43:39
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Hello! On Wed, Jul 22, 2026 at 01:29:37PM +0100, Oxana Kharitonova wrote:
quoted hunk ↗ jump to hunk
Move MQUEUE_MAGIC from ipc/mqueue.c to include/uapi/linux/magic.h so it can be shared by code outside of ipc/mqueue.c without duplicating the constant. Signed-off-by: Oxana Kharitonova <redacted> --- include/uapi/linux/magic.h | 2 ++ ipc/mqueue.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-)diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h index 4f2da935a76c..8e5d33bb1453 100644 --- a/include/uapi/linux/magic.h +++ b/include/uapi/linux/magic.h@@ -78,6 +78,8 @@ #define V9FS_MAGIC 0x01021997 +#define MQUEUE_MAGIC 0x19800202 + #define BDEVFS_MAGIC 0x62646576 #define DAXFS_MAGIC 0x64646178 #define BINFMTFS_MAGIC 0x42494e4ddiff --git a/ipc/mqueue.c b/ipc/mqueue.c index 4798b375972b..9515597d45ce 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c@@ -22,6 +22,7 @@ #include <linux/sysctl.h> #include <linux/poll.h> #include <linux/mqueue.h> +#include <linux/magic.h> #include <linux/msg.h> #include <linux/skbuff.h> #include <linux/vmalloc.h>@@ -47,7 +48,6 @@ struct mqueue_fs_context { bool newns; /* Set if newly created ipc namespace */ }; -#define MQUEUE_MAGIC 0x19800202 #define DIRENT_SIZE 20 #define FILENT_SIZE 80-- 2.50.1 (Apple Git-155)
The only reference to MQUEUE_MAGIC that I find in your patchset is from Landlock's kernel code -- For a value that gets serialized to disk, like for the other file systems, I think there is actually a legitimate use case for userspace to use that value, when dealing with raw images? But that's not the case here, I think? Should this live in include/linux/ipc_namespace.h instead? Or even be exposed as a helper function that lets you check whether an inode is referring to an mqueue? —Günther