ksmbd: synchronize lease breaks before renaming files

Break read and handle caching leases before entering the VFS rename path.
This keeps the destination name hidden until the lease holder acknowledges
the break.

Send the break synchronously before returning STATUS_PENDING for a rename.
This avoids a race between the interim response and notification handling.
Keep the existing asynchronous notification flow for all other lease break
paths so chained breaks retain their ordering.

Use the connection which owns the open for the notification.  A lease table
is shared by connections using the same client GUID.  Its saved connection
may belong to another active channel.  Use it only when the owning channel
is being released.

Check directory sharing before issuing a break to avoid unnecessary lease
breaks for a rename that must fail with a sharing violation.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

fs/smb/server/oplock.c

@@ -994,22 +994,28 @@ static void __smb2_lease_break_noti(struct work_struct *wk)
  * smb2_lease_break_noti() - break lease when a new client request
  *			write lease
  * @opinfo:		contains lease state information
- * @wait_ack:		wait for lease break acknowledgment from the client
+ * @sync:		send the lease break notification synchronously
  * @inc_epoch:		increment the lease epoch before sending the break
  *
  * Return:	0 on success, otherwise error
  */
-static int smb2_lease_break_noti(struct oplock_info *opinfo, bool wait_ack,
+static int smb2_lease_break_noti(struct oplock_info *opinfo, bool sync,
 				 bool inc_epoch)
 {
 	struct ksmbd_conn *conn;
 	struct ksmbd_work *work;
 	struct lease_break_info *br_info;
 	struct lease *lease = opinfo->o_lease;
-	int ret = 0;
 
 	conn = READ_ONCE(opinfo->conn);
-	if (lease->version == 2 && lease->l_lb && lease->l_lb->conn &&
+	/*
+	 * Keep a break on the channel which owns this open.  A lease table is
+	 * shared by connections with the same client GUID, so its connection
+	 * can belong to another active channel.  Only use it after the owning
+	 * channel is being released.
+	 */
+	if ((!conn || ksmbd_conn_releasing(conn)) && lease->version == 2 &&
+	    lease->l_lb && lease->l_lb->conn &&
 	    !ksmbd_conn_releasing(lease->l_lb->conn))
 		conn = lease->l_lb->conn;
 	if (!conn)
@@ -1042,11 +1048,11 @@ static int smb2_lease_break_noti(struct oplock_info *opinfo, bool wait_ack,
 
 	ksmbd_conn_r_count_inc(conn);
 	if (opinfo->op_state == OPLOCK_ACK_WAIT) {
-		INIT_WORK(&work->work, __smb2_lease_break_noti);
-		ksmbd_queue_work(work);
-		if (wait_ack) {
-			if (wait_for_break_ack(opinfo))
-				ret = ksmbd_invalidate_durable_fd(opinfo->fid);
+		if (sync) {
+			__smb2_lease_break_noti(&work->work);
+		} else {
+			INIT_WORK(&work->work, __smb2_lease_break_noti);
+			ksmbd_queue_work(work);
 		}
 	} else {
 		__smb2_lease_break_noti(&work->work);
@@ -1055,7 +1061,7 @@ static int smb2_lease_break_noti(struct oplock_info *opinfo, bool wait_ack,
 			lease_update_oplock_levels(opinfo->o_lease);
 		}
 	}
-	return ret;
+	return 0;
 }
 
 static void wait_lease_breaking(struct oplock_info *opinfo)
@@ -1076,7 +1082,8 @@ static void wait_lease_breaking(struct oplock_info *opinfo)
 }
 
 static int oplock_break(struct oplock_info *brk_opinfo, int req_op_level,
-			struct ksmbd_work *in_work, bool share_break)
+			struct ksmbd_work *in_work, bool share_break,
+			bool sync_lease_break)
 {
 	int err = 0;
 	bool sent_interim = false;
@@ -1137,13 +1144,6 @@ static int oplock_break(struct oplock_info *brk_opinfo, int req_op_level,
 			}
 		}
 
-		if (in_work && !sent_interim) {
-			setup_async_work(in_work, NULL, NULL);
-			smb2_send_interim_resp(in_work, STATUS_PENDING);
-			release_async_work(in_work);
-			sent_interim = true;
-		}
-
 		if (lease->state & (SMB2_LEASE_WRITE_CACHING_LE |
 				SMB2_LEASE_HANDLE_CACHING_LE)) {
 			brk_opinfo->op_state = OPLOCK_ACK_WAIT;
@@ -1157,8 +1157,16 @@ static int oplock_break(struct oplock_info *brk_opinfo, int req_op_level,
 			inc_epoch = false;
 			lease->reuse_epoch = false;
 		}
-		err = smb2_lease_break_noti(brk_opinfo, wait_ack, inc_epoch);
+		err = smb2_lease_break_noti(brk_opinfo, sync_lease_break, inc_epoch);
 		inc_epoch = false;
+		if (in_work && !sent_interim) {
+			setup_async_work(in_work, NULL, NULL);
+			smb2_send_interim_resp(in_work, STATUS_PENDING);
+			release_async_work(in_work);
+			sent_interim = true;
+		}
+		if (wait_ack && !err && wait_for_break_ack(brk_opinfo))
+			err = ksmbd_invalidate_durable_fd(brk_opinfo->fid);
 
 		ksmbd_debug(OPLOCK, "oplock granted = %d\n", brk_opinfo->level);
 		if (brk_opinfo->op_state == OPLOCK_CLOSING)
@@ -1230,7 +1238,8 @@ static void oplock_break_drain_none(struct list_head *head)
 	struct oplock_break_entry *ent, *tmp;
 
 	list_for_each_entry_safe(ent, tmp, head, list) {
-		oplock_break(ent->opinfo, SMB2_OPLOCK_LEVEL_NONE, NULL, false);
+		oplock_break(ent->opinfo, SMB2_OPLOCK_LEVEL_NONE, NULL, false,
+			     false);
 		list_del(&ent->list);
 		opinfo_put(ent->opinfo);
 		kfree(ent);
@@ -1547,7 +1556,7 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid,
 	prev_fid = prev_op_snapshot.fid;
 
 	err = oplock_break(prev_opinfo, break_level, work,
-			   share_ret < 0 && prev_opinfo->is_lease);
+			   share_ret < 0 && prev_opinfo->is_lease, false);
 	if (prev_durable_detached || (prev_durable_open && err == -ENOENT))
 		ksmbd_invalidate_durable_fd(prev_fid);
 	opinfo_put(prev_opinfo);
@@ -1645,7 +1654,7 @@ static bool smb_break_all_write_oplock(struct ksmbd_work *work,
 	}
 
 	brk_opinfo->open_trunc = is_trunc;
-	oplock_break(brk_opinfo, SMB2_OPLOCK_LEVEL_II, work, false);
+	oplock_break(brk_opinfo, SMB2_OPLOCK_LEVEL_II, work, false, false);
 	sent_break = true;
 	opinfo_put(brk_opinfo);
 
@@ -1660,10 +1669,12 @@ static bool smb_break_all_write_oplock(struct ksmbd_work *work,
  * @is_trunc:		truncate on open
  * @send_interim:	send interim response to the client
  * @send_oplock_break:	send oplock break notification to the client
+ * @sync_lease_break:	send the lease break notification synchronously
  */
 static void __smb_break_all_levII_oplock(struct ksmbd_work *work,
 					 struct ksmbd_file *fp, int is_trunc,
-					 bool send_interim, bool send_oplock_break)
+					 bool send_interim, bool send_oplock_break,
+					 bool sync_lease_break)
 {
 	struct oplock_info *op, *brk_op;
 	struct oplock_break_entry *ent, *tmp;
@@ -1736,7 +1747,7 @@ static void __smb_break_all_levII_oplock(struct ksmbd_work *work,
 				     brk_op->is_lease && !is_trunc ?
 				     SMB2_OPLOCK_LEVEL_II : SMB2_OPLOCK_LEVEL_NONE,
 				     send_interim && !sent_interim ? work : NULL,
-				     false);
+				     false, sync_lease_break);
 		}
 		sent_interim = true;
 		list_del(&ent->list);
@@ -1751,19 +1762,24 @@ static void __smb_break_all_levII_oplock(struct ksmbd_work *work,
 void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp,
 				int is_trunc)
 {
-	__smb_break_all_levII_oplock(work, fp, is_trunc, true, true);
+	__smb_break_all_levII_oplock(work, fp, is_trunc, true, true, false);
+}
+
+void smb_break_all_levII_oplock_rename(struct ksmbd_work *work, struct ksmbd_file *fp)
+{
+	__smb_break_all_levII_oplock(work, fp, 0, true, true, true);
 }
 
 void smb_break_all_levII_oplock_no_interim(struct ksmbd_work *work,
 					   struct ksmbd_file *fp, int is_trunc)
 {
-	__smb_break_all_levII_oplock(work, fp, is_trunc, false, true);
+	__smb_break_all_levII_oplock(work, fp, is_trunc, false, true, false);
 }
 
 void smb_break_all_levII_oplock_for_delete(struct ksmbd_work *work,
 					   struct ksmbd_file *fp)
 {
-	__smb_break_all_levII_oplock(work, fp, 0, false, false);
+	__smb_break_all_levII_oplock(work, fp, 0, false, false, false);
 }
 
 /**
@@ -1780,7 +1796,7 @@ void smb_break_all_oplock(struct ksmbd_work *work, struct ksmbd_file *fp)
 		return;
 
 	sent_break = smb_break_all_write_oplock(work, fp, 1);
-	__smb_break_all_levII_oplock(work, fp, 1, !sent_break, true);
+	__smb_break_all_levII_oplock(work, fp, 1, !sent_break, true, false);
 }
 
 /**
@@ -2271,7 +2287,6 @@ struct oplock_info *lookup_lease_in_table(struct ksmbd_conn *conn,
 			if (!atomic_inc_not_zero(&opinfo->refcount))
 				continue;
 			ret_op = opinfo;
-			break;
 		}
 		spin_unlock(&lease->lock);
 		if (ret_op) {

fs/smb/server/oplock.h

@@ -98,7 +98,8 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level,
 		     u64 pid, struct ksmbd_file *fp, __u16 tid,
 		     struct lease_ctx_info *lctx, int share_ret);
 void smb_break_all_levII_oplock(struct ksmbd_work *work,
-				struct ksmbd_file *fp, int is_trunc);
+					struct ksmbd_file *fp, int is_trunc);
+void smb_break_all_levII_oplock_rename(struct ksmbd_work *work, struct ksmbd_file *fp);
 void smb_break_all_levII_oplock_no_interim(struct ksmbd_work *work,
 					   struct ksmbd_file *fp, int is_trunc);
 void smb_break_all_levII_oplock_for_delete(struct ksmbd_work *work,

fs/smb/server/smb2pdu.c

@@ -7135,9 +7135,12 @@ static int smb2_rename(struct ksmbd_work *work,
 	if (!file_info->ReplaceIfExists)
 		flags = RENAME_NOREPLACE;
 
+	rc = ksmbd_vfs_check_rename_share(work, &fp->filp->f_path);
+	if (rc)
+		goto out;
+
+	smb_break_all_levII_oplock_rename(work, fp);
 	rc = ksmbd_vfs_rename(work, &fp->filp->f_path, new_name, flags);
-	if (!rc)
-		smb_break_all_levII_oplock(work, fp, 0);
 out:
 	kfree(new_name);
 	return rc;

fs/smb/server/vfs.c

@@ -658,15 +658,34 @@ int ksmbd_vfs_link(struct ksmbd_work *work, const char *oldname,
 	return err;
 }
 
+int ksmbd_vfs_check_rename_share(struct ksmbd_work *work,
+				 const struct path *old_path)
+{
+	struct ksmbd_file *parent_fp;
+	int err = 0;
+
+	parent_fp = ksmbd_lookup_fd_inode(old_path->dentry->d_parent);
+	if (!parent_fp)
+		return 0;
+
+	if ((parent_fp->daccess & FILE_DELETE_LE) ||
+	    (!parent_fp->attrib_only &&
+	     !(parent_fp->saccess & FILE_SHARE_DELETE_LE))) {
+		ksmbd_debug(VFS, "parent dir blocks delete sharing\n");
+		err = -ESHARE;
+	}
+	ksmbd_fd_put(work, parent_fp);
+	return err;
+}
+
 int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
-		     char *newname, int flags)
+			     char *newname, int flags)
 {
 	struct dentry *old_child = old_path->dentry;
 	struct path new_path;
 	struct qstr new_last;
 	struct renamedata rd;
 	struct ksmbd_share_config *share_conf = work->tcon->share_conf;
-	struct ksmbd_file *parent_fp;
 	int err, lookup_flags = LOOKUP_NO_SYMLINKS;
 
 	if (ksmbd_override_fsids(work))
@@ -704,18 +723,9 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
 		goto out3;
 	}
 
-	parent_fp = ksmbd_lookup_fd_inode(old_child->d_parent);
-	if (parent_fp) {
-		if ((parent_fp->daccess & FILE_DELETE_LE) ||
-		    (!parent_fp->attrib_only &&
-		     !(parent_fp->saccess & FILE_SHARE_DELETE_LE))) {
-			pr_err("parent dir blocks delete sharing\n");
-			err = -ESHARE;
-			ksmbd_fd_put(work, parent_fp);
-			goto out3;
-		}
-		ksmbd_fd_put(work, parent_fp);
-	}
+	err = ksmbd_vfs_check_rename_share(work, old_path);
+	if (err)
+		goto out3;
 
 	if (d_is_symlink(rd.new_dentry)) {
 		err = -EACCES;

fs/smb/server/vfs.h

@@ -89,7 +89,9 @@ int ksmbd_vfs_link(struct ksmbd_work *work,
 		   const char *oldname, const char *newname);
 int ksmbd_vfs_getattr(const struct path *path, struct kstat *stat);
 int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
-		     char *newname, int flags);
+			     char *newname, int flags);
+int ksmbd_vfs_check_rename_share(struct ksmbd_work *work,
+				 const struct path *old_path);
 int ksmbd_vfs_truncate(struct ksmbd_work *work,
 		       struct ksmbd_file *fp, loff_t size);
 struct srv_copychunk;