[PATCH 3/3] NFSD - Use MAY_ACT_AS_OWNER

From: NeilBrown
Date: Wed Oct 03 2018 - 21:03:46 EST


The NFSD_MAY_OWNER_OVERRIDE has exactly the same meaning
as the new MAY_ACT_AS_OWNER flag, so simplify the
code by making use of the identity.

The move NFSD_MAY_OWNER_OVERRIDE into NFSD_MAY_MASK, but that
is not a problem is it is always set together with a flag
that is already in the MASK.

Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
fs/nfsd/vfs.c | 11 ++++++-----
fs/nfsd/vfs.h | 14 +++++++-------
2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 55a099e47ba2..d89d23e6e2fe 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -2038,12 +2038,13 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
* We must trust the client to do permission checking - using "ACCESS"
* with NFSv3.
*/
- if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
- uid_eq(inode->i_uid, current_fsuid()))
- return 0;

- /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
- err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
+ /*
+ * This works as NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC}
+ * and NFSD_MAY_OWNER_OVERRIDE == MAY_ACT_AS_OWNER
+ */
+ err = inode_permission(inode, (acc & (MAY_READ|MAY_WRITE|
+ MAY_EXEC|MAY_ACT_AS_OWNER)));

/* Allow read access to binaries even when mode 111 */
if (err == -EACCES && S_ISREG(inode->i_mode) &&
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index 2b1c70d3757a..f6e96dba76a5 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -16,6 +16,7 @@
#define NFSD_MAY_EXEC MAY_EXEC
#define NFSD_MAY_WRITE MAY_WRITE
#define NFSD_MAY_READ MAY_READ
+#define NFSD_MAY_OWNER_OVERRIDE MAY_ACT_AS_OWNER
#define NFSD_MAY_SATTR (__MAY_UNUSED << 0)
#define NFSD_MAY_TRUNC (__MAY_UNUSED << 1)
#define NFSD_MAY_LOCK (__MAY_UNUSED << 2)
@@ -23,16 +24,15 @@
#define NFSD_MAY_MASK (__NFSD_MAY_FIRST_HINT - 1)

/* extra hints to permission and open routines: */
-#define NFSD_MAY_OWNER_OVERRIDE (__NFSD_MAY_FIRST_HINT << 0)
/* for device special files */
-#define NFSD_MAY_LOCAL_ACCESS (__NFSD_MAY_FIRST_HINT << 1)
-#define NFSD_MAY_BYPASS_GSS_ON_ROOT (__NFSD_MAY_FIRST_HINT << 2)
-#define NFSD_MAY_NOT_BREAK_LEASE (__NFSD_MAY_FIRST_HINT << 3)
-#define NFSD_MAY_BYPASS_GSS (__NFSD_MAY_FIRST_HINT << 4)
-#define NFSD_MAY_READ_IF_EXEC (__NFSD_MAY_FIRST_HINT << 5)
+#define NFSD_MAY_LOCAL_ACCESS (__NFSD_MAY_FIRST_HINT << 0)
+#define NFSD_MAY_BYPASS_GSS_ON_ROOT (__NFSD_MAY_FIRST_HINT << 1)
+#define NFSD_MAY_NOT_BREAK_LEASE (__NFSD_MAY_FIRST_HINT << 2)
+#define NFSD_MAY_BYPASS_GSS (__NFSD_MAY_FIRST_HINT << 3)
+#define NFSD_MAY_READ_IF_EXEC (__NFSD_MAY_FIRST_HINT << 4)

/* 64 bit readdir cookies for >= NFSv3 */
-#define NFSD_MAY_64BIT_COOKIE (__NFSD_MAY_FIRST_HINT << 6)
+#define NFSD_MAY_64BIT_COOKIE (__NFSD_MAY_FIRST_HINT << 5)

#define NFSD_MAY_CREATE (NFSD_MAY_EXEC|NFSD_MAY_WRITE)
#define NFSD_MAY_REMOVE (NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)