9p: fix error path during early mount

There was some cleanup issues during early mount which would trigger
a kernel bug for certain types of failure.  This patch reorganizes the
cleanup to get rid of the bad behavior.

This also merges the 9pnet and 9pnet_fd modules for the purpose of
configuration and initialization.  Keeping the fd transport separate
from the core 9pnet code seemed like a good idea at the time, but in
practice has caused more harm and confusion than good.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

2 files changed, 23 insertions, 24 deletions

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 5c1ccaf0416c..047c791427aa 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -206,12 +206,14 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
         v9ses->uid = ~0;
         v9ses->dfltuid = V9FS_DEFUID;
         v9ses->dfltgid = V9FS_DEFGID;
-        v9ses->options = kstrdup(data, GFP_KERNEL);
-        if (!v9ses->options) {
-                P9_DPRINTK(P9_DEBUG_ERROR,
+        if (data) {
+                v9ses->options = kstrdup(data, GFP_KERNEL);
+                if (!v9ses->options) {
+                        P9_DPRINTK(P9_DEBUG_ERROR,
                            "failed to allocate copy of option string\n");
-                retval = -ENOMEM;
-                goto error;
+                        retval = -ENOMEM;
+                        goto error;
+                }
         }
 
         rc = v9fs_parse_options(v9ses);
@@ -260,7 +262,6 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
         return fid;
 
 error:
-        v9fs_session_close(v9ses);
         return ERR_PTR(retval);
 }
 
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index ba10f172626d..bf59c3960494 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -128,29 +128,26 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
         fid = v9fs_session_init(v9ses, dev_name, data);
         if (IS_ERR(fid)) {
                 retval = PTR_ERR(fid);
-                fid = NULL;
-                kfree(v9ses);
-                v9ses = NULL;
-                goto error;
+                goto close_session;
         }
 
         st = p9_client_stat(fid);
         if (IS_ERR(st)) {
                 retval = PTR_ERR(st);
-                goto error;
+                goto clunk_fid;
         }
 
         sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
         if (IS_ERR(sb)) {
                 retval = PTR_ERR(sb);
-                goto error;
+                goto free_stat;
         }
         v9fs_fill_super(sb, v9ses, flags);
 
         inode = v9fs_get_inode(sb, S_IFDIR | mode);
         if (IS_ERR(inode)) {
                 retval = PTR_ERR(inode);
-                goto error;
+                goto release_sb;
         }
 
         inode->i_uid = uid;
@@ -159,7 +156,7 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
         root = d_alloc_root(inode);
         if (!root) {
                 retval = -ENOMEM;
-                goto error;
+                goto release_sb;
         }
 
         sb->s_root = root;
@@ -170,21 +167,22 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
 
         return simple_set_mnt(mnt, sb);
 
-error:
-        kfree(st);
-        if (fid)
-                p9_client_clunk(fid);
-
-        if (v9ses) {
-                v9fs_session_close(v9ses);
-                kfree(v9ses);
-        }
-
+release_sb:
         if (sb) {
                 up_write(&sb->s_umount);
                 deactivate_super(sb);
         }
 
+free_stat:
+        kfree(st);
+
+clunk_fid:
+        p9_client_clunk(fid);
+
+close_session:
+        v9fs_session_close(v9ses);
+        kfree(v9ses);
+
         return retval;
 }