1 files changed, 41 insertions, 4 deletions

diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index a58a3333ecc3..166dc8fd06c0 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -147,7 +147,7 @@ static int cifs_prepare_read(struct netfs_io_subrequest *subreq)
 	struct netfs_io_request *rreq = subreq->rreq;
 	struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq);
 	struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq);
-	struct TCP_Server_Info *server = req->server;
+	struct TCP_Server_Info *server;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(rreq->inode->i_sb);
 	size_t size;
 	int rc = 0;
@@ -156,6 +156,8 @@ static int cifs_prepare_read(struct netfs_io_subrequest *subreq)
 		rdata->xid = get_xid();
 		rdata->have_xid = true;
 	}
+
+	server = cifs_pick_channel(tlink_tcon(req->cfile->tlink)->ses);
 	rdata->server = server;
 
 	if (cifs_sb->ctx->rsize == 0)
@@ -198,7 +200,7 @@ static void cifs_issue_read(struct netfs_io_subrequest *subreq)
 	struct netfs_io_request *rreq = subreq->rreq;
 	struct cifs_io_subrequest *rdata = container_of(subreq, struct cifs_io_subrequest, subreq);
 	struct cifs_io_request *req = container_of(subreq->rreq, struct cifs_io_request, rreq);
-	struct TCP_Server_Info *server = req->server;
+	struct TCP_Server_Info *server = rdata->server;
 	int rc = 0;
 
 	cifs_dbg(FYI, "%s: op=%08x[%x] mapping=%p len=%zu/%zu\n",
@@ -265,7 +267,6 @@ static int cifs_init_request(struct netfs_io_request *rreq, struct file *file)
 		open_file = file->private_data;
 		rreq->netfs_priv = file->private_data;
 		req->cfile = cifsFileInfo_get(open_file);
-		req->server = cifs_pick_channel(tlink_tcon(req->cfile->tlink)->ses);
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
 			req->pid = req->cfile->pid;
 	} else if (rreq->origin != NETFS_WRITEBACK) {
@@ -1001,6 +1002,11 @@ int cifs_open(struct inode *inode, struct file *file)
 		} else {
 			_cifsFileInfo_put(cfile, true, false);
 		}
+	} else {
+		/* hard link on the defeered close file */
+		rc = cifs_get_hardlink_path(tcon, inode, file);
+		if (rc)
+			cifs_close_deferred_file(CIFS_I(inode));
 	}
 
 	if (server->oplocks)
@@ -2065,6 +2071,29 @@ cifs_move_llist(struct list_head *source, struct list_head *dest)
 		list_move(li, dest);
 }
 
+int
+cifs_get_hardlink_path(struct cifs_tcon *tcon, struct inode *inode,
+				struct file *file)
+{
+	struct cifsFileInfo *open_file = NULL;
+	struct cifsInodeInfo *cinode = CIFS_I(inode);
+	int rc = 0;
+
+	spin_lock(&tcon->open_file_lock);
+	spin_lock(&cinode->open_file_lock);
+
+	list_for_each_entry(open_file, &cinode->openFileList, flist) {
+		if (file->f_flags == open_file->f_flags) {
+			rc = -EINVAL;
+			break;
+		}
+	}
+
+	spin_unlock(&cinode->open_file_lock);
+	spin_unlock(&tcon->open_file_lock);
+	return rc;
+}
+
 void
 cifs_free_llist(struct list_head *llist)
 {
@@ -3047,7 +3076,8 @@ void cifs_oplock_break(struct work_struct *work)
 	struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
 						  oplock_break);
 	struct inode *inode = d_inode(cfile->dentry);
-	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+	struct super_block *sb = inode->i_sb;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 	struct cifsInodeInfo *cinode = CIFS_I(inode);
 	struct cifs_tcon *tcon;
 	struct TCP_Server_Info *server;
@@ -3057,6 +3087,12 @@ void cifs_oplock_break(struct work_struct *work)
 	__u64 persistent_fid, volatile_fid;
 	__u16 net_fid;
 
+	/*
+	 * Hold a reference to the superblock to prevent it and its inodes from
+	 * being freed while we are accessing cinode. Otherwise, _cifsFileInfo_put()
+	 * may release the last reference to the sb and trigger inode eviction.
+	 */
+	cifs_sb_active(sb);
 	wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
 			TASK_UNINTERRUPTIBLE);
 
@@ -3129,6 +3165,7 @@ oplock_break_ack:
 	cifs_put_tlink(tlink);
 out:
 	cifs_done_oplock_break(cinode);
+	cifs_sb_deactive(sb);
 }
 
 static int cifs_swap_activate(struct swap_info_struct *sis,