[PATCH 6/6] cifs: do not cache leased directories for longer than 30 seconds

[Ronnie Sahlberg <lsahlber@redhat.com>]

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/cached_dir.c | 32 ++++++++++++++++++++++++++++++--
 fs/cifs/cached_dir.h |  2 ++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/cached_dir.c b/fs/cifs/cached_dir.c
index f4d7700827b3..1c4a409bcb67 100644
--- a/fs/cifs/cached_dir.c
+++ b/fs/cifs/cached_dir.c
@@ -14,6 +14,7 @@
 
 static struct cached_fid *init_cached_dir(const char *path);
 static void free_cached_dir(struct cached_fid *cfid);
+static void smb2_cached_lease_timeout(struct work_struct *work);
 
 /*
  * Locking and reference count for cached directory handles:
@@ -321,6 +322,8 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	cfid->tcon = tcon;
 	cfid->time = jiffies;
 	cfid->is_open = true;
+	queue_delayed_work(cifsiod_wq, &cfid->lease_timeout, HZ * 30);
+	cfid->has_timeout = true;
 	cfid->has_lease = true;
 
 oshr_free:
@@ -447,6 +450,7 @@ void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
 		list_add(&cfid->entry, &entry);
 		cfids->num_entries--;
 		cfid->is_open = false;
+		cfid->has_timeout = false;
 		/* To prevent race with smb2_cached_lease_break() */
 		kref_get(&cfid->refcount);
 	}
@@ -455,6 +459,7 @@ void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
 	list_for_each_entry_safe(cfid, q, &entry, entry) {
 		cfid->on_list = false;
 		list_del(&cfid->entry);
+		cancel_delayed_work_sync(&cfid->lease_timeout);
 		cancel_work_sync(&cfid->lease_break);
 		if (cfid->has_lease) {
 			/*
@@ -477,12 +482,34 @@ smb2_cached_lease_break(struct work_struct *work)
 	struct cached_fid *cfid = container_of(work,
 				struct cached_fid, lease_break);
 
+	cancel_delayed_work_sync(&cfid->lease_timeout);
 	spin_lock(&cfid->cfids->cfid_list_lock);
+	if (!cfid->has_lease) {
+		spin_unlock(&cfid->cfids->cfid_list_lock);
+		return;
+	}
 	cfid->has_lease = false;
 	spin_unlock(&cfid->cfids->cfid_list_lock);
 	kref_put(&cfid->refcount, smb2_close_cached_fid);
 }
 
+static void
+smb2_cached_lease_timeout(struct work_struct *work)
+{
+	struct cached_fid *cfid = container_of(work,
+				struct cached_fid, lease_timeout.work);
+
+	spin_lock(&cfid->cfids->cfid_list_lock);
+	if (!cfid->has_timeout || !cfid->on_list) {
+		spin_unlock(&cfid->cfids->cfid_list_lock);
+		return;
+	}
+	cfid->has_timeout = false;
+	spin_unlock(&cfid->cfids->cfid_list_lock);
+
+	queue_work(cifsiod_wq, &cfid->lease_break);
+}
+
 int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
 {
 	struct cached_fids *cfids = tcon->cfids;
@@ -506,9 +533,9 @@ int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
 			cfid->on_list = false;
 			cfids->num_entries--;
 
-			queue_work(cifsiod_wq,
-				   &cfid->lease_break);
+			cfid->has_timeout = false;
 			spin_unlock(&cfids->cfid_list_lock);
+			queue_work(cifsiod_wq, &cfid->lease_break);
 			return true;
 		}
 	}
@@ -530,6 +557,7 @@ static struct cached_fid *init_cached_dir(const char *path)
 	}
 
 	INIT_WORK(&cfid->lease_break, smb2_cached_lease_break);
+	INIT_DELAYED_WORK(&cfid->lease_timeout, smb2_cached_lease_timeout);
 	INIT_LIST_HEAD(&cfid->entry);
 	INIT_LIST_HEAD(&cfid->dirents.entries);
 	mutex_init(&cfid->dirents.de_mutex);
diff --git a/fs/cifs/cached_dir.h b/fs/cifs/cached_dir.h
index e536304ca2ce..813cd30f7ca3 100644
--- a/fs/cifs/cached_dir.h
+++ b/fs/cifs/cached_dir.h
@@ -35,6 +35,7 @@ struct cached_fid {
 	struct cached_fids *cfids;
 	const char *path;
 	bool has_lease:1;
+	bool has_timeout:1;
 	bool is_open:1;
 	bool on_list:1;
 	bool file_all_info_is_valid:1;
@@ -45,6 +46,7 @@ struct cached_fid {
 	struct cifs_tcon *tcon;
 	struct dentry *dentry;
 	struct work_struct lease_break;
+	struct delayed_work lease_timeout;
 	struct smb2_file_all_info file_all_info;
 	struct cached_dirents dirents;
 };
-- 
2.35.3