fs/9p: Implement syncfs call back for 9Pfs

FIXME!! what about dotu ?

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

2 files changed, 25 insertions, 9 deletions

diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 6fa3cf5547d5..21bd803a3cc0 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -113,6 +113,7 @@ struct v9fs_session_info {
         struct list_head slist; /* list of sessions registered with v9fs */
         struct backing_dev_info bdi;
         struct rw_semaphore rename_sem;
+        struct p9_fid *root_fid; /* Used for file system sync */
 };
 
 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 76f867cf23f8..6985e2a7a118 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -152,7 +152,6 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
                 retval = PTR_ERR(inode);
                 goto release_sb;
         }
-
         root = d_alloc_root(inode);
         if (!root) {
                 iput(inode);
@@ -184,10 +183,21 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
                 p9stat_free(st);
                 kfree(st);
         }
+        v9fs_fid_add(root, fid);
         retval = v9fs_get_acl(inode, fid);
         if (retval)
                 goto release_sb;
-        v9fs_fid_add(root, fid);
+        /*
+         * Add the root fid to session info. This is used
+         * for file system sync. We want a cloned fid here
+         * so that we can do a sync_filesystem after a
+         * shrink_dcache_for_umount
+         */
+        v9ses->root_fid = v9fs_fid_clone(root);
+        if (IS_ERR(v9ses->root_fid)) {
+                retval = PTR_ERR(v9ses->root_fid);
+                goto release_sb;
+        }
 
         P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
         return dget(sb->s_root);
@@ -198,15 +208,11 @@ close_session:
         v9fs_session_close(v9ses);
         kfree(v9ses);
         return ERR_PTR(retval);
-
 release_sb:
         /*
-         * we will do the session_close and root dentry release
-         * in the below call. But we need to clunk fid, because we haven't
-         * attached the fid to dentry so it won't get clunked
-         * automatically.
+         * we will do the session_close and root dentry
+         * release in the below call.
          */
-        p9_client_clunk(fid);
         deactivate_locked_super(sb);
         return ERR_PTR(retval);
 }
@@ -224,7 +230,7 @@ static void v9fs_kill_super(struct super_block *s)
         P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
 
         kill_anon_super(s);
-
+        p9_client_clunk(v9ses->root_fid);
         v9fs_session_cancel(v9ses);
         v9fs_session_close(v9ses);
         kfree(v9ses);
@@ -277,6 +283,14 @@ done:
         return res;
 }
 
+static int v9fs_sync_fs(struct super_block *sb, int wait)
+{
+        struct v9fs_session_info *v9ses = sb->s_fs_info;
+
+        P9_DPRINTK(P9_DEBUG_VFS, "v9fs_sync_fs: super_block %p\n", sb);
+        return p9_client_sync_fs(v9ses->root_fid);
+}
+
 static const struct super_operations v9fs_super_ops = {
 #ifdef CONFIG_9P_FSCACHE
         .alloc_inode = v9fs_alloc_inode,
@@ -293,6 +307,7 @@ static const struct super_operations v9fs_super_ops_dotl = {
         .alloc_inode = v9fs_alloc_inode,
         .destroy_inode = v9fs_destroy_inode,
 #endif
+        .sync_fs = v9fs_sync_fs,
         .statfs = v9fs_statfs,
         .evict_inode = v9fs_evict_inode,
         .show_options = generic_show_options,