1 files changed, 53 insertions, 11 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 1e176e11dbfa..48ea9dfd5f02 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -358,13 +358,31 @@ cifsFileInfo_get(struct cifsFileInfo *cifs_file)
 	return cifs_file;
 }
 
-/*
- * Release a reference on the file private data. This may involve closing
- * the filehandle out on the server. Must be called without holding
- * tcon->open_file_lock and cifs_file->file_info_lock.
+/**
+ * cifsFileInfo_put - release a reference of file priv data
+ *
+ * Always potentially wait for oplock handler. See _cifsFileInfo_put().
  */
 void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 {
+	_cifsFileInfo_put(cifs_file, true);
+}
+
+/**
+ * _cifsFileInfo_put - release a reference of file priv data
+ *
+ * This may involve closing the filehandle @cifs_file out on the
+ * server. Must be called without holding tcon->open_file_lock and
+ * cifs_file->file_info_lock.
+ *
+ * If @wait_for_oplock_handler is true and we are releasing the last
+ * reference, wait for any running oplock break handler of the file
+ * and cancel any pending one. If calling this function from the
+ * oplock break handler, you need to pass false.
+ *
+ */
+void _cifsFileInfo_put(struct cifsFileInfo *cifs_file, bool wait_oplock_handler)
+{
 	struct inode *inode = d_inode(cifs_file->dentry);
 	struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
 	struct TCP_Server_Info *server = tcon->ses->server;
@@ -411,7 +429,8 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
 
 	spin_unlock(&tcon->open_file_lock);
 
-	oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
+	oplock_break_cancelled = wait_oplock_handler ?
+		cancel_work_sync(&cifs_file->oplock_break) : false;
 
 	if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
 		struct TCP_Server_Info *server = tcon->ses->server;
@@ -1128,6 +1147,10 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
 		return -EINVAL;
 	}
 
+	BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) >
+		     PAGE_SIZE);
+	max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr),
+			PAGE_SIZE);
 	max_num = (max_buf - sizeof(struct smb_hdr)) /
 						sizeof(LOCKING_ANDX_RANGE);
 	buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
@@ -1466,6 +1489,10 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
 	if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE)))
 		return -EINVAL;
 
+	BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) >
+		     PAGE_SIZE);
+	max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr),
+			PAGE_SIZE);
 	max_num = (max_buf - sizeof(struct smb_hdr)) /
 						sizeof(LOCKING_ANDX_RANGE);
 	buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
@@ -1623,8 +1650,20 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
 		rc = server->ops->mand_unlock_range(cfile, flock, xid);
 
 out:
-	if (flock->fl_flags & FL_POSIX && !rc)
+	if (flock->fl_flags & FL_POSIX) {
+		/*
+		 * If this is a request to remove all locks because we
+		 * are closing the file, it doesn't matter if the
+		 * unlocking failed as both cifs.ko and the SMB server
+		 * remove the lock on file close
+		 */
+		if (rc) {
+			cifs_dbg(VFS, "%s failed rc=%d\n", __func__, rc);
+			if (!(flock->fl_flags & FL_CLOSE))
+				return rc;
+		}
 		rc = locks_lock_file_wait(file, flock);
+	}
 	return rc;
 }
 
@@ -2881,14 +2920,16 @@ cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
 	 * these pages but not on the region from pos to ppos+len-1.
 	 */
 	written = cifs_user_writev(iocb, from);
-	if (written > 0 && CIFS_CACHE_READ(cinode)) {
+	if (CIFS_CACHE_READ(cinode)) {
 		/*
-		 * Windows 7 server can delay breaking level2 oplock if a write
-		 * request comes - break it on the client to prevent reading
-		 * an old data.
+		 * We have read level caching and we have just sent a write
+		 * request to the server thus making data in the cache stale.
+		 * Zap the cache and set oplock/lease level to NONE to avoid
+		 * reading stale data from the cache. All subsequent read
+		 * operations will read new data from the server.
 		 */
 		cifs_zap_mapping(inode);
-		cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
+		cifs_dbg(FYI, "Set Oplock/Lease to NONE for inode=%p after write\n",
 			 inode);
 		cinode->oplock = 0;
 	}
@@ -4114,6 +4155,7 @@ void cifs_oplock_break(struct work_struct *work)
 							     cinode);
 		cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
 	}
+	_cifsFileInfo_put(cfile, false /* do not wait for ourself */);
 	cifs_done_oplock_break(cinode);
 }