[PATCH 1/2] fs: add inode helpers for fsuid and fsgid

From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Christoph Hellwig <hch@infradead.org>,
	Dave Chinner <david@fromorbit.com>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Seth Forshee <seth.forshee@canonical.com>
Subject: [PATCH 1/2] fs: add inode helpers for fsuid and fsgid
Date: Mon, 13 Feb 2017 22:28:40 -0800	[thread overview]
Message-ID: <1487053720.3125.73.camel@HansenPartnership.com> (raw)
In-Reply-To: <1487053651.3125.72.camel@HansenPartnership.com>

Now that we have two different views of filesystem ids (the filesystem
view and the kernel view), we have a problem in that
current_fsuid/fsgid() return the kernel view but are sometimes used in
filesystem code where the filesystem view shoud be used.  This patch
introduces helpers to produce the filesystem view of current fsuid and
fsgid.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/include/linux/cred.h b/include/linux/cred.h
index f0e70a1..18e9c41 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -399,4 +399,9 @@ do {						\
 	*(_fsgid) = __cred->fsgid;		\
 } while(0)
 
+/* return the current id in the filesystem view */
+#define i_fsuid(i) from_kuid((i)->i_sb->s_user_ns, current_fsuid())
+#define i_fsgid(i) from_kgid((i)->i_sb->s_user_ns, current_fsgid())
+
+
 #endif /* _LINUX_CRED_H */
