Merge tag 'v6.9-rc-smb3-server-fixes' of git://git.samba.org/ksmbd

Pull smb server updates from Steve French:

 - add support for durable file handles (an important data integrity
   feature)

 - fixes for potential out of bounds issues

 - fix possible null dereference in close

 - getattr fixes

 - trivial typo fix and minor cleanup

* tag 'v6.9-rc-smb3-server-fixes' of git://git.samba.org/ksmbd:
  ksmbd: remove module version
  ksmbd: fix potencial out-of-bounds when buffer offset is invalid
  ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()
  ksmbd: Fix spelling mistake "connction" -> "connection"
  ksmbd: fix possible null-deref in smb_lazy_parent_lease_break_close
  ksmbd: add support for durable handles v1/v2
  ksmbd: mark SMB2_SESSION_EXPIRED to session when destroying previous session
  ksmbd: retrieve number of blocks using vfs_getattr in set_file_allocation_info
  ksmbd: replace generic_fillattr with vfs_getattr

fs/smb/server/glob.h

@@ -12,8 +12,6 @@
 #include "unicode.h"
 #include "vfs_cache.h"
 
-#define KSMBD_VERSION	"3.4.2"
-
 extern int ksmbd_debug_types;
 
 #define KSMBD_DEBUG_SMB		BIT(0)

fs/smb/server/ksmbd_netlink.h

@@ -75,6 +75,7 @@ struct ksmbd_heartbeat {
 #define KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION	BIT(1)
 #define KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL	BIT(2)
 #define KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION_OFF	BIT(3)
+#define KSMBD_GLOBAL_FLAG_DURABLE_HANDLE	BIT(4)
 
 /*
  * IPC request for ksmbd server startup

fs/smb/server/mgmt/user_session.c

@@ -156,7 +156,7 @@ void ksmbd_session_destroy(struct ksmbd_session *sess)
 	kfree(sess);
 }
 
-static struct ksmbd_session *__session_lookup(unsigned long long id)
+struct ksmbd_session *__session_lookup(unsigned long long id)
 {
 	struct ksmbd_session *sess;
 
@@ -305,6 +305,32 @@ struct preauth_session *ksmbd_preauth_session_alloc(struct ksmbd_conn *conn,
 	return sess;
 }
 
+void destroy_previous_session(struct ksmbd_conn *conn,
+			      struct ksmbd_user *user, u64 id)
+{
+	struct ksmbd_session *prev_sess;
+	struct ksmbd_user *prev_user;
+
+	down_write(&sessions_table_lock);
+	down_write(&conn->session_lock);
+	prev_sess = __session_lookup(id);
+	if (!prev_sess || prev_sess->state == SMB2_SESSION_EXPIRED)
+		goto out;
+
+	prev_user = prev_sess->user;
+	if (!prev_user ||
+	    strcmp(user->name, prev_user->name) ||
+	    user->passkey_sz != prev_user->passkey_sz ||
+	    memcmp(user->passkey, prev_user->passkey, user->passkey_sz))
+		goto out;
+
+	ksmbd_destroy_file_table(&prev_sess->file_table);
+	prev_sess->state = SMB2_SESSION_EXPIRED;
+out:
+	up_write(&conn->session_lock);
+	up_write(&sessions_table_lock);
+}
+
 static bool ksmbd_preauth_session_id_match(struct preauth_session *sess,
 					   unsigned long long id)
 {

fs/smb/server/mgmt/user_session.h

@@ -88,8 +88,11 @@ struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn,
 int ksmbd_session_register(struct ksmbd_conn *conn,
 			   struct ksmbd_session *sess);
 void ksmbd_sessions_deregister(struct ksmbd_conn *conn);
+struct ksmbd_session *__session_lookup(unsigned long long id);
 struct ksmbd_session *ksmbd_session_lookup_all(struct ksmbd_conn *conn,
 					       unsigned long long id);
+void destroy_previous_session(struct ksmbd_conn *conn,
+			      struct ksmbd_user *user, u64 id);
 struct preauth_session *ksmbd_preauth_session_alloc(struct ksmbd_conn *conn,
 						    u64 sess_id);
 struct preauth_session *ksmbd_preauth_session_lookup(struct ksmbd_conn *conn,

fs/smb/server/oplock.c

@@ -159,7 +159,8 @@ static struct oplock_info *opinfo_get_list(struct ksmbd_inode *ci)
 	opinfo = list_first_or_null_rcu(&ci->m_op_list, struct oplock_info,
 					op_entry);
 	if (opinfo) {
-		if (!atomic_inc_not_zero(&opinfo->refcount))
+		if (opinfo->conn == NULL ||
+		    !atomic_inc_not_zero(&opinfo->refcount))
 			opinfo = NULL;
 		else {
 			atomic_inc(&opinfo->conn->r_count);
@@ -527,7 +528,7 @@ static struct oplock_info *same_client_has_lease(struct ksmbd_inode *ci,
 	 */
 	read_lock(&ci->m_lock);
 	list_for_each_entry(opinfo, &ci->m_op_list, op_entry) {
-		if (!opinfo->is_lease)
+		if (!opinfo->is_lease || !opinfo->conn)
 			continue;
 		read_unlock(&ci->m_lock);
 		lease = opinfo->o_lease;
@@ -641,7 +642,7 @@ static void __smb2_oplock_break_noti(struct work_struct *wk)
 	struct smb2_hdr *rsp_hdr;
 	struct ksmbd_file *fp;
 
-	fp = ksmbd_lookup_durable_fd(br_info->fid);
+	fp = ksmbd_lookup_global_fd(br_info->fid);
 	if (!fp)
 		goto out;
 
@@ -1106,7 +1107,7 @@ void smb_send_parent_lease_break_noti(struct ksmbd_file *fp,
 
 	read_lock(&p_ci->m_lock);
 	list_for_each_entry(opinfo, &p_ci->m_op_list, op_entry) {
-		if (!opinfo->is_lease)
+		if (opinfo->conn == NULL || !opinfo->is_lease)
 			continue;
 
 		if (opinfo->o_lease->state != SMB2_OPLOCK_LEVEL_NONE &&
@@ -1142,7 +1143,7 @@ void smb_lazy_parent_lease_break_close(struct ksmbd_file *fp)
 	opinfo = rcu_dereference(fp->f_opinfo);
 	rcu_read_unlock();
 
-	if (!opinfo->is_lease || opinfo->o_lease->version != 2)
+	if (!opinfo || !opinfo->is_lease || opinfo->o_lease->version != 2)
 		return;
 
 	p_ci = ksmbd_inode_lookup_lock(fp->filp->f_path.dentry->d_parent);
@@ -1151,7 +1152,7 @@ void smb_lazy_parent_lease_break_close(struct ksmbd_file *fp)
 
 	read_lock(&p_ci->m_lock);
 	list_for_each_entry(opinfo, &p_ci->m_op_list, op_entry) {
-		if (!opinfo->is_lease)
+		if (opinfo->conn == NULL || !opinfo->is_lease)
 			continue;
 
 		if (opinfo->o_lease->state != SMB2_OPLOCK_LEVEL_NONE) {
@@ -1361,6 +1362,9 @@ void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp,
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(brk_op, &ci->m_op_list, op_entry) {
+		if (brk_op->conn == NULL)
+			continue;
+
 		if (!atomic_inc_not_zero(&brk_op->refcount))
 			continue;
 
@@ -1496,11 +1500,10 @@ void create_lease_buf(u8 *rbuf, struct lease *lease)
 /**
  * parse_lease_state() - parse lease context containted in file open request
  * @open_req:	buffer containing smb2 file open(create) request
- * @is_dir:	whether leasing file is directory
  *
  * Return:  oplock state, -ENOENT if create lease context not found
  */
-struct lease_ctx_info *parse_lease_state(void *open_req, bool is_dir)
+struct lease_ctx_info *parse_lease_state(void *open_req)
 {
 	struct create_context *cc;
 	struct smb2_create_req *req = (struct smb2_create_req *)open_req;
@@ -1518,12 +1521,7 @@ struct lease_ctx_info *parse_lease_state(void *open_req, bool is_dir)
 		struct create_lease_v2 *lc = (struct create_lease_v2 *)cc;
 
 		memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE);
-		if (is_dir) {
-			lreq->req_state = lc->lcontext.LeaseState &
-				~SMB2_LEASE_WRITE_CACHING_LE;
-			lreq->is_dir = true;
-		} else
-			lreq->req_state = lc->lcontext.LeaseState;
+		lreq->req_state = lc->lcontext.LeaseState;
 		lreq->flags = lc->lcontext.LeaseFlags;
 		lreq->epoch = lc->lcontext.Epoch;
 		lreq->duration = lc->lcontext.LeaseDuration;
@@ -1646,6 +1644,8 @@ void create_durable_v2_rsp_buf(char *cc, struct ksmbd_file *fp)
 	buf->Name[3] = 'Q';
 
 	buf->Timeout = cpu_to_le32(fp->durable_timeout);
+	if (fp->is_persistent)
+		buf->Flags = cpu_to_le32(SMB2_DHANDLE_FLAG_PERSISTENT);
 }
 
 /**
@@ -1813,3 +1813,71 @@ struct oplock_info *lookup_lease_in_table(struct ksmbd_conn *conn,
 	read_unlock(&lease_list_lock);
 	return ret_op;
 }
+
+int smb2_check_durable_oplock(struct ksmbd_conn *conn,
+			      struct ksmbd_share_config *share,
+			      struct ksmbd_file *fp,
+			      struct lease_ctx_info *lctx,
+			      char *name)
+{
+	struct oplock_info *opinfo = opinfo_get(fp);
+	int ret = 0;
+
+	if (!opinfo)
+		return 0;
+
+	if (opinfo->is_lease == false) {
+		if (lctx) {
+			pr_err("create context include lease\n");
+			ret = -EBADF;
+			goto out;
+		}
+
+		if (opinfo->level != SMB2_OPLOCK_LEVEL_BATCH) {
+			pr_err("oplock level is not equal to SMB2_OPLOCK_LEVEL_BATCH\n");
+			ret = -EBADF;
+		}
+
+		goto out;
+	}
+
+	if (memcmp(conn->ClientGUID, fp->client_guid,
+				SMB2_CLIENT_GUID_SIZE)) {
+		ksmbd_debug(SMB, "Client guid of fp is not equal to the one of connection\n");
+		ret = -EBADF;
+		goto out;
+	}
+
+	if (!lctx) {
+		ksmbd_debug(SMB, "create context does not include lease\n");
+		ret = -EBADF;
+		goto out;
+	}
+
+	if (memcmp(opinfo->o_lease->lease_key, lctx->lease_key,
+				SMB2_LEASE_KEY_SIZE)) {
+		ksmbd_debug(SMB,
+			    "lease key of fp does not match lease key in create context\n");
+		ret = -EBADF;
+		goto out;
+	}
+
+	if (!(opinfo->o_lease->state & SMB2_LEASE_HANDLE_CACHING_LE)) {
+		ksmbd_debug(SMB, "lease state does not contain SMB2_LEASE_HANDLE_CACHING\n");
+		ret = -EBADF;
+		goto out;
+	}
+
+	if (opinfo->o_lease->version != lctx->version) {
+		ksmbd_debug(SMB,
+			    "lease version of fp does not match the one in create context\n");
+		ret = -EBADF;
+		goto out;
+	}
+
+	if (!ksmbd_inode_pending_delete(fp))
+		ret = ksmbd_validate_name_reconnect(share, fp, name);
+out:
+	opinfo_put(opinfo);
+	return ret;
+}

fs/smb/server/oplock.h

@@ -111,7 +111,7 @@ void opinfo_put(struct oplock_info *opinfo);
 
 /* Lease related functions */
 void create_lease_buf(u8 *rbuf, struct lease *lease);
-struct lease_ctx_info *parse_lease_state(void *open_req, bool is_dir);
+struct lease_ctx_info *parse_lease_state(void *open_req);
 __u8 smb2_map_lease_to_oplock(__le32 lease_state);
 int lease_read_to_write(struct oplock_info *opinfo);
 
@@ -130,4 +130,9 @@ void destroy_lease_table(struct ksmbd_conn *conn);
 void smb_send_parent_lease_break_noti(struct ksmbd_file *fp,
 				      struct lease_ctx_info *lctx);
 void smb_lazy_parent_lease_break_close(struct ksmbd_file *fp);
+int smb2_check_durable_oplock(struct ksmbd_conn *conn,
+			      struct ksmbd_share_config *share,
+			      struct ksmbd_file *fp,
+			      struct lease_ctx_info *lctx,
+			      char *name);
 #endif /* __KSMBD_OPLOCK_H */

fs/smb/server/server.c

@@ -625,7 +625,6 @@ static void __exit ksmbd_server_exit(void)
 }
 
 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
-MODULE_VERSION(KSMBD_VERSION);
 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
 MODULE_LICENSE("GPL");
 MODULE_SOFTDEP("pre: ecb");

fs/smb/server/smb2misc.c

@@ -101,13 +101,17 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
 		*len = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferLength);
 		break;
 	case SMB2_TREE_CONNECT:
-		*off = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset);
+		*off = max_t(unsigned short int,
+			     le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset),
+			     offsetof(struct smb2_tree_connect_req, Buffer));
 		*len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength);
 		break;
 	case SMB2_CREATE:
 	{
 		unsigned short int name_off =
-			le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset);
+			max_t(unsigned short int,
+			      le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset),
+			      offsetof(struct smb2_create_req, Buffer));
 		unsigned short int name_len =
 			le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);
 
@@ -128,11 +132,15 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
 		break;
 	}
 	case SMB2_QUERY_INFO:
-		*off = le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset);
+		*off = max_t(unsigned int,
+			     le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset),
+			     offsetof(struct smb2_query_info_req, Buffer));
 		*len = le32_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferLength);
 		break;
 	case SMB2_SET_INFO:
-		*off = le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset);
+		*off = max_t(unsigned int,
+			     le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset),
+			     offsetof(struct smb2_set_info_req, Buffer));
 		*len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength);
 		break;
 	case SMB2_READ:
@@ -142,7 +150,7 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
 	case SMB2_WRITE:
 		if (((struct smb2_write_req *)hdr)->DataOffset ||
 		    ((struct smb2_write_req *)hdr)->Length) {
-			*off = max_t(unsigned int,
+			*off = max_t(unsigned short int,
 				     le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset),
 				     offsetof(struct smb2_write_req, Buffer));
 			*len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length);
@@ -153,7 +161,9 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
 		*len = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoLength);
 		break;
 	case SMB2_QUERY_DIRECTORY:
-		*off = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset);
+		*off = max_t(unsigned short int,
+			     le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset),
+			     offsetof(struct smb2_query_directory_req, Buffer));
 		*len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength);
 		break;
 	case SMB2_LOCK:
@@ -168,7 +178,9 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
 		break;
 	}
 	case SMB2_IOCTL:
-		*off = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset);
+		*off = max_t(unsigned int,
+			     le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset),
+			     offsetof(struct smb2_ioctl_req, Buffer));
 		*len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount);
 		break;
 	default:

fs/smb/server/smb2ops.c

@@ -256,6 +256,9 @@ void init_smb3_02_server(struct ksmbd_conn *conn)
 
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL)
 		conn->vals->capabilities |= SMB2_GLOBAL_CAP_MULTI_CHANNEL;
+
+	if (server_conf.flags & KSMBD_GLOBAL_FLAG_DURABLE_HANDLE)
+		conn->vals->capabilities |= SMB2_GLOBAL_CAP_PERSISTENT_HANDLES;
 }
 
 /**
@@ -283,6 +286,9 @@ int init_smb3_11_server(struct ksmbd_conn *conn)
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL)
 		conn->vals->capabilities |= SMB2_GLOBAL_CAP_MULTI_CHANNEL;
 
+	if (server_conf.flags & KSMBD_GLOBAL_FLAG_DURABLE_HANDLE)
+		conn->vals->capabilities |= SMB2_GLOBAL_CAP_PERSISTENT_HANDLES;
+
 	INIT_LIST_HEAD(&conn->preauth_sess_table);
 	return 0;
 }

fs/smb/server/smb2pdu.h

@@ -72,6 +72,18 @@ struct create_durable_req_v2 {
 	__u8 CreateGuid[16];
 } __packed;
 
+struct create_durable_reconn_req {
+	struct create_context ccontext;
+	__u8   Name[8];
+	union {
+		__u8  Reserved[16];
+		struct {
+			__u64 PersistentFileId;
+			__u64 VolatileFileId;
+		} Fid;
+	} Data;
+} __packed;
+
 struct create_durable_reconn_v2_req {
 	struct create_context ccontext;
 	__u8   Name[8];
@@ -98,6 +110,9 @@ struct create_durable_rsp {
 	} Data;
 } __packed;
 
+/* See MS-SMB2 2.2.13.2.11 */
+/* Flags */
+#define SMB2_DHANDLE_FLAG_PERSISTENT	0x00000002
 struct create_durable_v2_rsp {
 	struct create_context ccontext;
 	__u8   Name[8];

fs/smb/server/smb_common.c

@@ -457,10 +457,13 @@ int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
 			}
 
 			ksmbd_kstat.kstat = &kstat;
-			ksmbd_vfs_fill_dentry_attrs(work,
-						    idmap,
-						    dentry,
-						    &ksmbd_kstat);
+			rc = ksmbd_vfs_fill_dentry_attrs(work,
+							 idmap,
+							 dentry,
+							 &ksmbd_kstat);
+			if (rc)
+				break;
+
 			rc = fn(conn, info_level, d_info, &ksmbd_kstat);
 			if (rc)
 				break;

fs/smb/server/vfs.c

@@ -1682,11 +1682,19 @@ int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work,
 				struct dentry *dentry,
 				struct ksmbd_kstat *ksmbd_kstat)
 {
+	struct ksmbd_share_config *share_conf = work->tcon->share_conf;
 	u64 time;
 	int rc;
+	struct path path = {
+		.mnt = share_conf->vfs_path.mnt,
+		.dentry = dentry,
+	};
 
-	generic_fillattr(idmap, STATX_BASIC_STATS, d_inode(dentry),
-			 ksmbd_kstat->kstat);
+	rc = vfs_getattr(&path, ksmbd_kstat->kstat,
+			 STATX_BASIC_STATS | STATX_BTIME,
+			 AT_STATX_SYNC_AS_STAT);
+	if (rc)
+		return rc;
 
 	time = ksmbd_UnixTimeToNT(ksmbd_kstat->kstat->ctime);
 	ksmbd_kstat->create_time = time;

fs/smb/server/vfs_cache.c

@@ -305,7 +305,8 @@ static void __ksmbd_close_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
 
 	fd_limit_close();
 	__ksmbd_remove_durable_fd(fp);
-	__ksmbd_remove_fd(ft, fp);
+	if (ft)
+		__ksmbd_remove_fd(ft, fp);
 
 	close_id_del_oplock(fp);
 	filp = fp->filp;
@@ -465,11 +466,32 @@ struct ksmbd_file *ksmbd_lookup_fd_slow(struct ksmbd_work *work, u64 id,
 	return fp;
 }
 
-struct ksmbd_file *ksmbd_lookup_durable_fd(unsigned long long id)
+struct ksmbd_file *ksmbd_lookup_global_fd(unsigned long long id)
 {
 	return __ksmbd_lookup_fd(&global_ft, id);
 }
 
+struct ksmbd_file *ksmbd_lookup_durable_fd(unsigned long long id)
+{
+	struct ksmbd_file *fp;
+
+	fp = __ksmbd_lookup_fd(&global_ft, id);
+	if (fp && fp->conn) {
+		ksmbd_put_durable_fd(fp);
+		fp = NULL;
+	}
+
+	return fp;
+}
+
+void ksmbd_put_durable_fd(struct ksmbd_file *fp)
+{
+	if (!atomic_dec_and_test(&fp->refcount))
+		return;
+
+	__ksmbd_close_fd(NULL, fp);
+}
+
 struct ksmbd_file *ksmbd_lookup_fd_cguid(char *cguid)
 {
 	struct ksmbd_file	*fp = NULL;
@@ -639,6 +661,32 @@ __close_file_table_ids(struct ksmbd_file_table *ft,
 	return num;
 }
 
+static inline bool is_reconnectable(struct ksmbd_file *fp)
+{
+	struct oplock_info *opinfo = opinfo_get(fp);
+	bool reconn = false;
+
+	if (!opinfo)
+		return false;
+
+	if (opinfo->op_state != OPLOCK_STATE_NONE) {
+		opinfo_put(opinfo);
+		return false;
+	}
+
+	if (fp->is_resilient || fp->is_persistent)
+		reconn = true;
+	else if (fp->is_durable && opinfo->is_lease &&
+		 opinfo->o_lease->state & SMB2_LEASE_HANDLE_CACHING_LE)
+		reconn = true;
+
+	else if (fp->is_durable && opinfo->level == SMB2_OPLOCK_LEVEL_BATCH)
+		reconn = true;
+
+	opinfo_put(opinfo);
+	return reconn;
+}
+
 static bool tree_conn_fd_check(struct ksmbd_tree_connect *tcon,
 			       struct ksmbd_file *fp)
 {
@@ -648,7 +696,28 @@ static bool tree_conn_fd_check(struct ksmbd_tree_connect *tcon,
 static bool session_fd_check(struct ksmbd_tree_connect *tcon,
 			     struct ksmbd_file *fp)
 {
-	return false;
+	struct ksmbd_inode *ci;
+	struct oplock_info *op;
+	struct ksmbd_conn *conn;
+
+	if (!is_reconnectable(fp))
+		return false;
+
+	conn = fp->conn;
+	ci = fp->f_ci;
+	write_lock(&ci->m_lock);
+	list_for_each_entry_rcu(op, &ci->m_op_list, op_entry) {
+		if (op->conn != conn)
+			continue;
+		op->conn = NULL;
+	}
+	write_unlock(&ci->m_lock);
+
+	fp->conn = NULL;
+	fp->tcon = NULL;
+	fp->volatile_id = KSMBD_NO_FID;
+
+	return true;
 }
 
 void ksmbd_close_tree_conn_fds(struct ksmbd_work *work)
@@ -687,6 +756,68 @@ void ksmbd_free_global_file_table(void)
 	ksmbd_destroy_file_table(&global_ft);
 }
 
+int ksmbd_validate_name_reconnect(struct ksmbd_share_config *share,
+				  struct ksmbd_file *fp, char *name)
+{
+	char *pathname, *ab_pathname;
+	int ret = 0;
+
+	pathname = kmalloc(PATH_MAX, GFP_KERNEL);
+	if (!pathname)
+		return -EACCES;
+
+	ab_pathname = d_path(&fp->filp->f_path, pathname, PATH_MAX);
+	if (IS_ERR(ab_pathname)) {
+		kfree(pathname);
+		return -EACCES;
+	}
+
+	if (name && strcmp(&ab_pathname[share->path_sz + 1], name)) {
+		ksmbd_debug(SMB, "invalid name reconnect %s\n", name);
+		ret = -EINVAL;
+	}
+
+	kfree(pathname);
+
+	return ret;
+}
+
+int ksmbd_reopen_durable_fd(struct ksmbd_work *work, struct ksmbd_file *fp)
+{
+	struct ksmbd_inode *ci;
+	struct oplock_info *op;
+
+	if (!fp->is_durable || fp->conn || fp->tcon) {
+		pr_err("Invalid durable fd [%p:%p]\n", fp->conn, fp->tcon);
+		return -EBADF;
+	}
+
+	if (has_file_id(fp->volatile_id)) {
+		pr_err("Still in use durable fd: %llu\n", fp->volatile_id);
+		return -EBADF;
+	}
+
+	fp->conn = work->conn;
+	fp->tcon = work->tcon;
+
+	ci = fp->f_ci;
+	write_lock(&ci->m_lock);
+	list_for_each_entry_rcu(op, &ci->m_op_list, op_entry) {
+		if (op->conn)
+			continue;
+		op->conn = fp->conn;
+	}
+	write_unlock(&ci->m_lock);
+
+	__open_id(&work->sess->file_table, fp, OPEN_ID_TYPE_VOLATILE_ID);
+	if (!has_file_id(fp->volatile_id)) {
+		fp->conn = NULL;
+		fp->tcon = NULL;
+		return -EBADF;
+	}
+	return 0;
+}
+
 int ksmbd_init_file_table(struct ksmbd_file_table *ft)
 {
 	ft->idr = kzalloc(sizeof(struct idr), GFP_KERNEL);

fs/smb/server/vfs_cache.h

@@ -14,6 +14,7 @@
 #include <linux/workqueue.h>
 
 #include "vfs.h"
+#include "mgmt/share_config.h"
 
 /* Windows style file permissions for extended response */
 #define	FILE_GENERIC_ALL	0x1F01FF
@@ -106,6 +107,9 @@ struct ksmbd_file {
 	int				dot_dotdot[2];
 	unsigned int			f_state;
 	bool				reserve_lease_break;
+	bool				is_durable;
+	bool				is_persistent;
+	bool				is_resilient;
 };
 
 static inline void set_ctx_actor(struct dir_context *ctx,
@@ -141,7 +145,9 @@ struct ksmbd_file *ksmbd_lookup_fd_slow(struct ksmbd_work *work, u64 id,
 void ksmbd_fd_put(struct ksmbd_work *work, struct ksmbd_file *fp);
 struct ksmbd_inode *ksmbd_inode_lookup_lock(struct dentry *d);
 void ksmbd_inode_put(struct ksmbd_inode *ci);
+struct ksmbd_file *ksmbd_lookup_global_fd(unsigned long long id);
 struct ksmbd_file *ksmbd_lookup_durable_fd(unsigned long long id);
+void ksmbd_put_durable_fd(struct ksmbd_file *fp);
 struct ksmbd_file *ksmbd_lookup_fd_cguid(char *cguid);
 struct ksmbd_file *ksmbd_lookup_fd_inode(struct dentry *dentry);
 unsigned int ksmbd_open_durable_fd(struct ksmbd_file *fp);
@@ -173,6 +179,9 @@ void ksmbd_set_inode_pending_delete(struct ksmbd_file *fp);
 void ksmbd_clear_inode_pending_delete(struct ksmbd_file *fp);
 void ksmbd_fd_set_delete_on_close(struct ksmbd_file *fp,
 				  int file_info);
+int ksmbd_reopen_durable_fd(struct ksmbd_work *work, struct ksmbd_file *fp);
+int ksmbd_validate_name_reconnect(struct ksmbd_share_config *share,
+				  struct ksmbd_file *fp, char *name);
 int ksmbd_init_file_cache(void);
 void ksmbd_exit_file_cache(void);
 #endif /* __VFS_CACHE_H__ */