cifs: Deferred close for files

When file is closed, SMB2 close request is not sent to server
immediately and is deferred for acregmax defined interval. When file is
reopened by same process for read or write, the file handle
is reused if an oplock is held.

When client receives a oplock/lease break, file is closed immediately
if reference count is zero, else oplock is downgraded.

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index b23a0ee8c6f8..d88b4b523dcc 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1154,6 +1154,14 @@ struct cifs_pending_open {
 	__u32 oplock;
 };
 
+struct cifs_deferred_close {
+	struct list_head dlist;
+	struct tcon_link *tlink;
+	__u16  netfid;
+	__u64  persistent_fid;
+	__u64  volatile_fid;
+};
+
 /*
  * This info hangs off the cifsFileInfo structure, pointed to by llist.
  * This is used to track byte stream locks on the file
@@ -1248,6 +1256,9 @@ struct cifsFileInfo {
 	struct cifs_search_info srch_inf;
 	struct work_struct oplock_break; /* work for oplock breaks */
 	struct work_struct put; /* work for the final part of _put */
+	struct delayed_work deferred;
+	bool oplock_break_received; /* Flag to indicate oplock break */
+	bool deferred_scheduled;
 };
 
 struct cifs_io_parms {
@@ -1392,6 +1403,7 @@ struct cifsInodeInfo {
 #define CIFS_INO_DELETE_PENDING		  (3) /* delete pending on server */
 #define CIFS_INO_INVALID_MAPPING	  (4) /* pagecache is invalid */
 #define CIFS_INO_LOCK			  (5) /* lock bit for synchronization */
+#define CIFS_INO_MODIFIED_ATTR            (6) /* Indicate change in mtime/ctime */
 	unsigned long flags;
 	spinlock_t writers_lock;
 	unsigned int writers;		/* Number of writers on this inode */
@@ -1404,6 +1416,8 @@ struct cifsInodeInfo {
 	struct fscache_cookie *fscache;
 #endif
 	struct inode vfs_inode;
+	struct list_head deferred_closes; /* list of deferred closes */
+	spinlock_t deferred_lock; /* protection on deferred list */
 };
 
 static inline struct cifsInodeInfo *
@@ -1871,11 +1885,14 @@ extern bool disable_legacy_dialects;  /* forbid vers=1.0 and vers=2.0 mounts */
 
 void cifs_oplock_break(struct work_struct *work);
 void cifs_queue_oplock_break(struct cifsFileInfo *cfile);
+void smb2_deferred_work_close(struct work_struct *work);
 
+extern const struct slow_work_ops cifs_oplock_break_ops;
 extern struct workqueue_struct *cifsiod_wq;
 extern struct workqueue_struct *decrypt_wq;
 extern struct workqueue_struct *fileinfo_put_wq;
 extern struct workqueue_struct *cifsoplockd_wq;
+extern struct workqueue_struct *deferredclose_wq;
 extern __u32 cifs_lock_secret;
 
 extern mempool_t *cifs_mid_poolp;