9 files changed, 78 insertions, 13 deletions

diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index 57e0b80a5274..c0236e753bc8 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -37,6 +37,15 @@ For Plan 9 From User Space applications (http://swtch.com/plan9)
 
         mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
 
+For server running on QEMU host with virtio transport:
+
+        mount -t 9p -o trans=virtio <mount_tag> /mnt/9
+
+where mount_tag is the tag associated by the server to each of the exported
+mount points. Each 9P export is seen by the client as a virtio device with an
+associated "mount_tag" property. Available mount tags can be
+seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
+
 OPTIONS
 =======
 
@@ -47,7 +56,7 @@ OPTIONS
                         fd      - used passed file descriptors for connection
                                 (see rfdno and wfdno)
                         virtio  - connect to the next virtio channel available
-                                (from lguest or KVM with trans_virtio module)
+                                (from QEMU with trans_virtio module)
                         rdma    - connect to a specified RDMA channel
 
   uname=name    user name to attempt mount as on the remote server.  The
@@ -85,7 +94,12 @@ OPTIONS
 
   port=n        port to connect to on the remote server
 
-  noextend      force legacy mode (no 9p2000.u semantics)
+  noextend      force legacy mode (no 9p2000.u or 9p2000.L semantics)
+
+  version=name  Select 9P protocol version. Valid options are:
+                        9p2000          - Legacy mode (same as noextend)
+                        9p2000.u        - Use 9P2000.u protocol
+                        9p2000.L        - Use 9P2000.L protocol
 
   dfltuid       attempt to mount as a particular uid
 
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index 82ee460e534d..7317b39b2815 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -111,7 +111,7 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 {
         int i, n, l, clone, any, access;
         u32 uid;
-        struct p9_fid *fid;
+        struct p9_fid *fid, *old_fid = NULL;
         struct dentry *d, *ds;
         struct v9fs_session_info *v9ses;
         char **wnames, *uname;
@@ -184,10 +184,18 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
                 l = min(n - i, P9_MAXWELEM);
                 fid = p9_client_walk(fid, l, &wnames[i], clone);
                 if (IS_ERR(fid)) {
+                        if (old_fid) {
+                                /*
+                                 * If we fail, clunk fid which are mapping
+                                 * to path component and not the last component
+                                 * of the path.
+                                 */
+                                p9_client_clunk(old_fid);
+                        }
                         kfree(wnames);
                         return fid;
                 }
-
+                old_fid = fid;
                 i += l;
                 clone = 0;
         }
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index cb57d3326182..5c5bc8480070 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -242,7 +242,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
         list_add(&v9ses->slist, &v9fs_sessionlist);
         spin_unlock(&v9fs_sessionlist_lock);
 
-        v9ses->flags = V9FS_PROTO_2000U | V9FS_ACCESS_USER;
+        v9ses->flags = V9FS_ACCESS_USER;
         strcpy(v9ses->uname, V9FS_DEFUSER);
         strcpy(v9ses->aname, V9FS_DEFANAME);
         v9ses->uid = ~0;
@@ -263,8 +263,10 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
                 goto error;
         }
 
-        if (!p9_is_proto_dotu(v9ses->clnt))
-                v9ses->flags &= ~V9FS_PROTO_2000U;
+        if (p9_is_proto_dotl(v9ses->clnt))
+                v9ses->flags |= V9FS_PROTO_2000L;
+        else if (p9_is_proto_dotu(v9ses->clnt))
+                v9ses->flags |= V9FS_PROTO_2000U;
 
         v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 
@@ -341,6 +343,19 @@ void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
         p9_client_disconnect(v9ses->clnt);
 }
 
+/**
+ * v9fs_session_begin_cancel - Begin terminate of a session
+ * @v9ses: session to terminate
+ *
+ * After this call we don't allow any request other than clunk.
+ */
+
+void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
+{
+        P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
+        p9_client_begin_disconnect(v9ses->clnt);
+}
+
 extern int v9fs_error_init(void);
 
 static struct kobject *v9fs_kobj;
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 6b801d1ddf4b..a0a8d3dd1361 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -108,6 +108,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
                                                                         char *);
 void v9fs_session_close(struct v9fs_session_info *v9ses);
 void v9fs_session_cancel(struct v9fs_session_info *v9ses);
+void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 
 #define V9FS_MAGIC 0x01021997
 
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 909711f57c0d..0adfd64dfcee 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -131,6 +131,8 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
         rdir = (struct p9_rdir *) fid->rdir;
 
         err = mutex_lock_interruptible(&rdir->mutex);
+        if (err)
+                return err;
         while (err == 0) {
                 if (rdir->tail == rdir->head) {
                         err = v9fs_file_readn(filp, rdir->buf, NULL,
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 63c2b5af268a..f2434fc9d2c4 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -432,6 +432,7 @@ error:
 
 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 {
+        int retval;
         struct inode *file_inode;
         struct v9fs_session_info *v9ses;
         struct p9_fid *v9fid;
@@ -445,7 +446,10 @@ static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
         if (IS_ERR(v9fid))
                 return PTR_ERR(v9fid);
 
-        return p9_client_remove(v9fid);
+        retval = p9_client_remove(v9fid);
+        if (!retval)
+                drop_nlink(file_inode);
+        return retval;
 }
 
 static int
@@ -657,6 +661,9 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
                 dir, dentry->d_name.name, dentry, nameidata);
 
+        if (dentry->d_name.len > NAME_MAX)
+                return ERR_PTR(-ENAMETOOLONG);
+
         sb = dir->i_sb;
         v9ses = v9fs_inode2v9ses(dir);
         dfid = v9fs_fid_lookup(dentry->d_parent);
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index a271549d9e21..491108bd6e0d 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -194,6 +194,7 @@ static void v9fs_kill_super(struct super_block *s)
 
         kill_anon_super(s);
 
+        v9fs_session_cancel(v9ses);
         v9fs_session_close(v9ses);
         kfree(v9ses);
         s->s_fs_info = NULL;
@@ -206,7 +207,7 @@ v9fs_umount_begin(struct super_block *sb)
         struct v9fs_session_info *v9ses;
 
         v9ses = sb->s_fs_info;
-        v9fs_session_cancel(v9ses);
+        v9fs_session_begin_cancel(v9ses);
 }
 
 static const struct super_operations v9fs_super_ops = {
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index f076dfa75ae8..4f3760afc20f 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -54,6 +54,7 @@ enum p9_proto_versions{
 
 enum p9_trans_status {
         Connected,
+        BeginDisconnect,
         Disconnected,
         Hung,
 };
@@ -198,6 +199,7 @@ int p9_client_version(struct p9_client *);
 struct p9_client *p9_client_create(const char *dev_name, char *options);
 void p9_client_destroy(struct p9_client *clnt);
 void p9_client_disconnect(struct p9_client *clnt);
+void p9_client_begin_disconnect(struct p9_client *clnt);
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
                                         char *uname, u32 n_uname, char *aname);
 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
diff --git a/net/9p/client.c b/net/9p/client.c
index 6e6b928a5972..0aa79faa9850 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -72,9 +72,10 @@ inline int p9_is_proto_dotu(struct p9_client *clnt)
 EXPORT_SYMBOL(p9_is_proto_dotu);
 
 /* Interpret mount option for protocol version */
-static unsigned char get_protocol_version(const substring_t *name)
+static int get_protocol_version(const substring_t *name)
 {
-        unsigned char version = -EINVAL;
+        int version = -EINVAL;
+
         if (!strncmp("9p2000", name->from, name->to-name->from)) {
                 version = p9_proto_legacy;
                 P9_DPRINTK(P9_DEBUG_9P, "Protocol version: Legacy\n");
@@ -534,7 +535,12 @@ p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 
         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 
-        if (c->status != Connected)
+        /* we allow for any status other than disconnected */
+        if (c->status == Disconnected)
+                return ERR_PTR(-EIO);
+
+        /* if status is begin_disconnected we allow only clunk request */
+        if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
                 return ERR_PTR(-EIO);
 
         if (signal_pending(current)) {
@@ -800,8 +806,10 @@ void p9_client_destroy(struct p9_client *clnt)
 
         v9fs_put_trans(clnt->trans_mod);
 
-        list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
+        list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
+                printk(KERN_INFO "Found fid %d not clunked\n", fid->fid);
                 p9_fid_destroy(fid);
+        }
 
         if (clnt->fidpool)
                 p9_idpool_destroy(clnt->fidpool);
@@ -819,6 +827,13 @@ void p9_client_disconnect(struct p9_client *clnt)
 }
 EXPORT_SYMBOL(p9_client_disconnect);
 
+void p9_client_begin_disconnect(struct p9_client *clnt)
+{
+        P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
+        clnt->status = BeginDisconnect;
+}
+EXPORT_SYMBOL(p9_client_begin_disconnect);
+
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
         char *uname, u32 n_uname, char *aname)
 {