smb3: add support for statfs for smb3.1.1 posix extensions

Output now matches expected stat -f output for all fields
except for Namelen and ID which were addressed in a companion
patch (which retrieves them from existing SMB3 mechanisms
and works whether POSIX enabled or not)
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

fs/cifs/smb2ops.c

@@ -1533,6 +1533,39 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 	return rc;
 }
 
+#ifdef CONFIG_CIFS_SMB311
+static int
+smb311_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
+	     struct kstatfs *buf)
+{
+	int rc;
+	__le16 srch_path = 0; /* Null - open root of share */
+	u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
+	struct cifs_open_parms oparms;
+	struct cifs_fid fid;
+
+	if (!tcon->posix_extensions)
+		return smb2_queryfs(xid, tcon, buf);
+
+	oparms.tcon = tcon;
+	oparms.desired_access = FILE_READ_ATTRIBUTES;
+	oparms.disposition = FILE_OPEN;
+	oparms.create_options = 0;
+	oparms.fid = &fid;
+	oparms.reconnect = false;
+
+	rc = SMB2_open(xid, &oparms, &srch_path, &oplock, NULL, NULL, NULL);
+	if (rc)
+		return rc;
+
+	rc = SMB311_posix_qfs_info(xid, tcon, fid.persistent_fid,
+				   fid.volatile_fid, buf);
+	buf->f_type = SMB2_MAGIC_NUMBER;
+	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
+	return rc;
+}
+#endif /* SMB311 */
+
 static bool
 smb2_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2)
 {
@@ -3338,7 +3371,7 @@ struct smb_version_operations smb311_operations = {
 	.is_status_pending = smb2_is_status_pending,
 	.is_session_expired = smb2_is_session_expired,
 	.oplock_response = smb2_oplock_response,
-	.queryfs = smb2_queryfs,
+	.queryfs = smb311_queryfs,
 	.mand_lock = smb2_mand_lock,
 	.mand_unlock_range = smb2_unlock_range,
 	.push_mand_locks = smb2_push_mandatory_locks,

fs/cifs/smb2pdu.c

@@ -3938,6 +3938,27 @@ copy_fs_info_to_kstatfs(struct smb2_fs_full_size_info *pfs_inf,
 	return;
 }
 
+#ifdef CONFIG_CIFS_SMB311
+static void
+copy_posix_fs_info_to_kstatfs(FILE_SYSTEM_POSIX_INFO *response_data,
+			struct kstatfs *kst)
+{
+	kst->f_bsize = le32_to_cpu(response_data->BlockSize);
+	kst->f_blocks = le64_to_cpu(response_data->TotalBlocks);
+	kst->f_bfree =  le64_to_cpu(response_data->BlocksAvail);
+	if (response_data->UserBlocksAvail == cpu_to_le64(-1))
+		kst->f_bavail = kst->f_bfree;
+	else
+		kst->f_bavail = le64_to_cpu(response_data->UserBlocksAvail);
+	if (response_data->TotalFileNodes != cpu_to_le64(-1))
+		kst->f_files = le64_to_cpu(response_data->TotalFileNodes);
+	if (response_data->FreeFileNodes != cpu_to_le64(-1))
+		kst->f_ffree = le64_to_cpu(response_data->FreeFileNodes);
+
+	return;
+}
+#endif /* SMB311 */
+
 static int
 build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level,
 		   int outbuf_len, u64 persistent_fid, u64 volatile_fid)
@@ -3974,6 +3995,56 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level,
 	return 0;
 }
 
+#ifdef CONFIG_CIFS_SMB311
+int
+SMB311_posix_qfs_info(const unsigned int xid, struct cifs_tcon *tcon,
+	      u64 persistent_fid, u64 volatile_fid, struct kstatfs *fsdata)
+{
+	struct smb_rqst rqst;
+	struct smb2_query_info_rsp *rsp = NULL;
+	struct kvec iov;
+	struct kvec rsp_iov;
+	int rc = 0;
+	int resp_buftype;
+	struct cifs_ses *ses = tcon->ses;
+	FILE_SYSTEM_POSIX_INFO *info = NULL;
+	int flags = 0;
+
+	rc = build_qfs_info_req(&iov, tcon, FS_POSIX_INFORMATION,
+				sizeof(FILE_SYSTEM_POSIX_INFO),
+				persistent_fid, volatile_fid);
+	if (rc)
+		return rc;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
+	memset(&rqst, 0, sizeof(struct smb_rqst));
+	rqst.rq_iov = &iov;
+	rqst.rq_nvec = 1;
+
+	rc = cifs_send_recv(xid, ses, &rqst, &resp_buftype, flags, &rsp_iov);
+	cifs_small_buf_release(iov.iov_base);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
+		goto posix_qfsinf_exit;
+	}
+	rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
+
+	info = (FILE_SYSTEM_POSIX_INFO *)(
+		le16_to_cpu(rsp->OutputBufferOffset) + (char *)rsp);
+	rc = validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
+			  le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
+			  sizeof(FILE_SYSTEM_POSIX_INFO));
+	if (!rc)
+		copy_posix_fs_info_to_kstatfs(info, fsdata);
+
+posix_qfsinf_exit:
+	free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+	return rc;
+}
+#endif /* SMB311 */
+
 int
 SMB2_QFS_info(const unsigned int xid, struct cifs_tcon *tcon,
 	      u64 persistent_fid, u64 volatile_fid, struct kstatfs *fsdata)

fs/cifs/smb2pdu.h

@@ -1223,6 +1223,7 @@ struct smb2_lease_ack {
 #define FS_DRIVER_PATH_INFORMATION	9 /* Local only */
 #define FS_VOLUME_FLAGS_INFORMATION	10 /* Local only */
 #define FS_SECTOR_SIZE_INFORMATION	11 /* SMB3 or later. Query */
+#define FS_POSIX_INFORMATION		100 /* SMB3.1.1 POSIX. Query */
 
 struct smb2_fs_full_size_info {
 	__le64 TotalAllocationUnits;

fs/cifs/smb2proto.h

@@ -197,6 +197,9 @@ void smb2_cancelled_close_fid(struct work_struct *work);
 extern int SMB2_QFS_info(const unsigned int xid, struct cifs_tcon *tcon,
 			 u64 persistent_file_id, u64 volatile_file_id,
 			 struct kstatfs *FSData);
+extern int SMB311_posix_qfs_info(const unsigned int xid, struct cifs_tcon *tcon,
+			 u64 persistent_file_id, u64 volatile_file_id,
+			 struct kstatfs *FSData);
 extern int SMB2_QFS_attr(const unsigned int xid, struct cifs_tcon *tcon,
 			 u64 persistent_file_id, u64 volatile_file_id, int lvl);
 extern int SMB2_lock(const unsigned int xid, struct cifs_tcon *tcon,