[PATCH 3/3] fscache: Print cookie debugging information

[David Howells]

---

 fs/afs/cache.c          |   11 +++++++++++
 fs/fscache/cookie.c     |    7 +++++--
 fs/nfs/fscache-index.c  |   11 +++++++++++
 include/linux/fscache.h |    2 ++
 4 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/fs/afs/cache.c b/fs/afs/cache.c
index f6d0a21e8052..c16b10dcf895 100644
--- a/fs/afs/cache.c
+++ b/fs/afs/cache.c
@@ -32,10 +32,21 @@ struct fscache_cookie_def afs_volume_cache_index_def = {
 	.type		= FSCACHE_COOKIE_TYPE_INDEX,
 };
 
+static void afs_vnode_print_cookie(void *cookie_netfs_data, char prefix)
+{
+	struct afs_vnode *vnode = cookie_netfs_data;
+
+	pr_err("kAFS    : %c-vnode %llx:%llx:%x\n",
+	       prefix, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
+	pr_err("kAFS    : %c-vol v=%p %llx\n",
+	       prefix, vnode->volume, vnode->volume->vid);
+}
+
 struct fscache_cookie_def afs_vnode_cache_index_def = {
 	.name		= "AFS.vnode",
 	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
 	.check_aux	= afs_vnode_cache_check_aux,
+	.print		= afs_vnode_print_cookie,
 };
 
 /*
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 6931e45b7d59..50db256e6593 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -41,8 +41,9 @@ static void fscache_print_cookie(struct fscache_cookie *cookie, char prefix)
 	       prefix, cookie, cookie->parent, cookie->flags,
 	       atomic_read(&cookie->n_children),
 	       atomic_read(&cookie->n_active));
-	pr_err("%c-cookie d=%p n=%p\n",
-	       prefix, cookie->def, cookie->netfs_data);
+	pr_err("%c-cookie d=%p n=%p [%s]\n",
+	       prefix, cookie->def, cookie->netfs_data,
+	       cookie->def ? cookie->def->name : "");
 
 	object = READ_ONCE(cookie->backing_objects.first);
 	if (object)
@@ -55,6 +56,8 @@ static void fscache_print_cookie(struct fscache_cookie *cookie, char prefix)
 	for (loop = 0; loop < cookie->key_len; loop++)
 		pr_cont("%02x", k[loop]);
 	pr_cont("'\n");
+	if (cookie->def && cookie->def->print)
+		cookie->def->print(cookie->netfs_data, prefix);
 }
 
 void fscache_free_cookie(struct fscache_cookie *cookie)
diff --git a/fs/nfs/fscache-index.c b/fs/nfs/fscache-index.c
index 666415d13d52..bba6753cdfb7 100644
--- a/fs/nfs/fscache-index.c
+++ b/fs/nfs/fscache-index.c
@@ -124,6 +124,16 @@ static void nfs_fh_put_context(void *cookie_netfs_data, void *context)
 		put_nfs_open_context(context);
 }
 
+static void nfs_inode_print_cookie(void *cookie_netfs_data, char prefix)
+{
+	struct nfs_inode *nfsi = cookie_netfs_data;
+	struct inode *i = &nfsi->vfs_inode;
+
+	pr_err("NFS     : %c-nfs fl=%lx cv=%lx ii=%lx if=%x sb=%p sf=%lx\n",
+	       prefix, nfsi->flags, nfsi->cache_validity,
+	       i->i_ino, i->i_flags, i->i_sb, i->i_sb->s_flags);
+}
+
 /*
  * Define the inode object for FS-Cache.  This is used to describe an inode
  * object to fscache_acquire_cookie().  It is keyed by the NFS file handle for
@@ -139,4 +149,5 @@ const struct fscache_cookie_def nfs_fscache_inode_object_def = {
 	.check_aux	= nfs_fscache_inode_check_aux,
 	.get_context	= nfs_fh_get_context,
 	.put_context	= nfs_fh_put_context,
+	.print		= nfs_inode_print_cookie,
 };
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 84b90a79d75a..84525722522e 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -114,6 +114,8 @@ struct fscache_cookie_def {
 	void (*mark_page_cached)(void *cookie_netfs_data,
 				 struct address_space *mapping,
 				 struct page *page);
+
+	void (*print)(void *cookie_netfs_data, char prefix);
 };
 
 /*