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>

4 files changed, 72 insertions, 3 deletions

diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index 7ac1faec2bde..410ffd6ceb5f 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -83,4 +83,6 @@ static inline void v9fs_invalidate_inode_attr(struct inode *inode)
         v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
         return;
 }
+
+int v9fs_open_to_dotl_flags(int flags);
 #endif
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 3c173fcc2c5a..c2f107583125 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -65,7 +65,7 @@ int v9fs_file_open(struct inode *inode, struct file *file)
         v9inode = V9FS_I(inode);
         v9ses = v9fs_inode2v9ses(inode);
         if (v9fs_proto_dotl(v9ses))
-                omode = file->f_flags;
+                omode = v9fs_open_to_dotl_flags(file->f_flags);
         else
                 omode = v9fs_uflags2omode(file->f_flags,
                                         v9fs_proto_dotu(v9ses));
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 3563cace0a2e..9e3ea6ce6951 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -553,6 +553,19 @@ v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 }
 
 /**
+ * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
+ * plan 9 AT flag.
+ * @flags: flags to convert
+ */
+static int v9fs_at_to_dotl_flags(int flags)
+{
+        int rflags = 0;
+        if (flags & AT_REMOVEDIR)
+                rflags |= P9_DOTL_AT_REMOVEDIR;
+        return rflags;
+}
+
+/**
  * v9fs_remove - helper function to remove files and directories
  * @dir: directory inode that is being deleted
  * @dentry:  dentry that is being deleted
@@ -579,7 +592,8 @@ static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
                 return retval;
         }
         if (v9fs_proto_dotl(v9ses))
-                retval = p9_client_unlinkat(dfid, dentry->d_name.name, flags);
+                retval = p9_client_unlinkat(dfid, dentry->d_name.name,
+                                            v9fs_at_to_dotl_flags(flags));
         if (retval == -EOPNOTSUPP) {
                 /* Try the one based on path */
                 v9fid = v9fs_fid_clone(dentry);
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",