ceph: fix file mode calculation

open(2) must always include one of O_RDONLY, O_WRONLY, or O_RDWR.  No need
for any O_APPEND special case.

Passing O_WRONLY|O_RDWR is undefined according to the man page, but the
Linux VFS interprets this as O_RDWR, so we'll do the same.

This fixes open(2) with flags O_RDWR|O_APPEND, which was incorrectly being
translated to readonly.

Reported-by: Fyodor Ustinov <ufm@ufm.su>
Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 10 insertions, 7 deletions

diff --git a/net/ceph/ceph_fs.c b/net/ceph/ceph_fs.c
index a3a3a31d3c37..41466ccb972a 100644
--- a/net/ceph/ceph_fs.c
+++ b/net/ceph/ceph_fs.c
@@ -36,16 +36,19 @@ int ceph_flags_to_mode(int flags)
         if ((flags & O_DIRECTORY) == O_DIRECTORY)
                 return CEPH_FILE_MODE_PIN;
 #endif
-        if ((flags & O_APPEND) == O_APPEND)
-                flags |= O_WRONLY;
 
-        if ((flags & O_ACCMODE) == O_RDWR)
-                mode = CEPH_FILE_MODE_RDWR;
-        else if ((flags & O_ACCMODE) == O_WRONLY)
+        switch (flags & O_ACCMODE) {
+        case O_WRONLY:
                 mode = CEPH_FILE_MODE_WR;
-        else
+                break;
+        case O_RDONLY:
                 mode = CEPH_FILE_MODE_RD;
-
+                break;
+        case O_RDWR:
+        case O_ACCMODE: /* this is what the VFS does */
+                mode = CEPH_FILE_MODE_RDWR;
+                break;
+        }
 #ifdef O_LAZY
         if (flags & O_LAZY)
                 mode |= CEPH_FILE_MODE_LAZY;