fs/9p: Add OS dependent open flags in 9p protocol

Some of the flags are OS/arch dependent we add a 9p
protocol value which maps to asm-generic/fcntl.h values in Linux
Based on the original patch from Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

1 files changed, 54 insertions, 1 deletions

diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index a3f2540cc4b2..aded79fcd5cf 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -191,6 +191,58 @@ v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid,
         return inode;
 }
 
+struct dotl_openflag_map {
+        int open_flag;
+        int dotl_flag;
+};
+
+static int v9fs_mapped_dotl_flags(int flags)
+{
+        int i;
+        int rflags = 0;
+        struct dotl_openflag_map dotl_oflag_map[] = {
+                { O_CREAT,      P9_DOTL_CREATE },
+                { O_EXCL,       P9_DOTL_EXCL },
+                { O_NOCTTY,     P9_DOTL_NOCTTY },
+                { O_TRUNC,      P9_DOTL_TRUNC },
+                { O_APPEND,     P9_DOTL_APPEND },
+                { O_NONBLOCK,   P9_DOTL_NONBLOCK },
+                { O_DSYNC,      P9_DOTL_DSYNC },
+                { FASYNC,       P9_DOTL_FASYNC },
+                { O_DIRECT,     P9_DOTL_DIRECT },
+                { O_LARGEFILE,  P9_DOTL_LARGEFILE },
+                { O_DIRECTORY,  P9_DOTL_DIRECTORY },
+                { O_NOFOLLOW,   P9_DOTL_NOFOLLOW },
+                { O_NOATIME,    P9_DOTL_NOATIME },
+                { O_CLOEXEC,    P9_DOTL_CLOEXEC },
+                { O_SYNC,       P9_DOTL_SYNC},
+        };
+        for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) {
+                if (flags & dotl_oflag_map[i].open_flag)
+                        rflags |= dotl_oflag_map[i].dotl_flag;
+        }
+        return rflags;
+}
+
+/**
+ * v9fs_open_to_dotl_flags- convert Linux specific open flags to
+ * plan 9 open flag.
+ * @flags: flags to convert
+ */
+int v9fs_open_to_dotl_flags(int flags)
+{
+        int rflags = 0;
+
+        /*
+         * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY
+         * and P9_DOTL_NOACCESS
+         */
+        rflags |= flags & O_ACCMODE;
+        rflags |= v9fs_mapped_dotl_flags(flags);
+
+        return rflags;
+}
+
 /**
  * v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
  * @dir: directory inode that is being created
@@ -259,7 +311,8 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode,
                            "Failed to get acl values in creat %d\n", err);
                 goto error;
         }
-        err = p9_client_create_dotl(ofid, name, flags, mode, gid, &qid);
+        err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
+                                    mode, gid, &qid);
         if (err < 0) {
                 P9_DPRINTK(P9_DEBUG_VFS,
                                 "p9_client_open_dotl failed in creat %d\n",