CIFS: Do not assume one credit for async responses

If we don't receive a response we can't assume that the server
granted one credit. Assume zero credits in such cases.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 0af87bd..2ff209e 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2924,9 +2924,10 @@ smb2_echo_callback(struct mid_q_entry *mid)
 {
        struct TCP_Server_Info *server = mid->callback_data;
        struct smb2_echo_rsp *rsp = (struct smb2_echo_rsp *)mid->resp_buf;
-       unsigned int credits_received = 1;
+       unsigned int credits_received = 0;
 
-       if (mid->mid_state == MID_RESPONSE_RECEIVED)
+       if (mid->mid_state == MID_RESPONSE_RECEIVED
+           || mid->mid_state == MID_RESPONSE_MALFORMED)
                credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
 
        DeleteMidQEntry(mid);
@@ -3183,7 +3184,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
        struct TCP_Server_Info *server = tcon->ses->server;
        struct smb2_sync_hdr *shdr =
                                (struct smb2_sync_hdr *)rdata->iov[0].iov_base;
-       unsigned int credits_received = 1;
+       unsigned int credits_received = 0;
        struct smb_rqst rqst = { .rq_iov = rdata->iov,
                                 .rq_nvec = 2,
                                 .rq_pages = rdata->pages,
@@ -3222,6 +3223,9 @@ smb2_readv_callback(struct mid_q_entry *mid)
                task_io_account_read(rdata->got_bytes);
                cifs_stats_bytes_read(tcon, rdata->got_bytes);
                break;
+       case MID_RESPONSE_MALFORMED:
+               credits_received = le16_to_cpu(shdr->CreditRequest);
+               /* fall through */
        default:
                if (rdata->result != -ENODATA)
                        rdata->result = -EIO;
@@ -3407,7 +3411,7 @@ smb2_writev_callback(struct mid_q_entry *mid)
        struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
        unsigned int written;
        struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf;
-       unsigned int credits_received = 1;
+       unsigned int credits_received = 0;
 
        switch (mid->mid_state) {
        case MID_RESPONSE_RECEIVED:
@@ -3435,6 +3439,9 @@ smb2_writev_callback(struct mid_q_entry *mid)
        case MID_RETRY_NEEDED:
                wdata->result = -EAGAIN;
                break;
+       case MID_RESPONSE_MALFORMED:
+               credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+               /* fall through */
        default:
                wdata->result = -EIO;
                break;