TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

smb: client: let smbd_post_send_iter() respect the peers max_send_size and transmit all data

Browse Source 
We should not send smbdirect_data_transfer messages larger than
the negotiated max_send_size, typically 1364 bytes, which means
24 bytes of the smbdirect_data_transfer header + 1340 payload bytes.

This happened when doing an SMB2 write with more than 1340 bytes
(which is done inline as it's below rdma_readwrite_threshold).

It means the peer resets the connection.

When testing between cifs.ko and ksmbd.ko something like this
is logged:

client:

    CIFS: VFS: RDMA transport re-established
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    siw: got TERMINATE. layer 1, type 2, code 2
    CIFS: VFS: \\carina Send error in SessSetup = -11
    smb2_reconnect: 12 callbacks suppressed
    CIFS: VFS: reconnect tcon failed rc = -11
    CIFS: VFS: reconnect tcon failed rc = -11
    CIFS: VFS: reconnect tcon failed rc = -11
    CIFS: VFS: SMB: Zero rsize calculated, using minimum value 65536

and:

    CIFS: VFS: RDMA transport re-established
    siw: got TERMINATE. layer 1, type 2, code 2
    CIFS: VFS: smbd_recv:1894 disconnected
    siw: got TERMINATE. layer 1, type 2, code 2

The ksmbd dmesg is showing things like:

    smb_direct: Recv error. status='local length error (1)' opcode=128
    smb_direct: disconnected
    smb_direct: Recv error. status='local length error (1)' opcode=128
    ksmbd: smb_direct: disconnected
    ksmbd: sock_read failed: -107

As smbd_post_send_iter() limits the transmitted number of bytes
we need loop over it in order to transmit the whole iter.

Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Meetakshi Setiya <msetiya@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: <stable+noautosel@kernel.org> # sp->max_send_size should be info->max_send_size in backports
Fixes: 3d78fe73fa ("cifs: Build the RDMA SGE list directly from an iterator")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Stefan Metzmacher
2025-06-25 10:16:38 +02:00
committed by Steve French
parent ff8abbd248
commit 1944f6ab49
1 changed files with 27 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/smb/client/smbdirect.c
+27 -4
View File
@@ -907,8 +907,10 @@ wait_send_queue:
.local_dma_lkey = sc->ib.pd->local_dma_lkey,
.direction = DMA_TO_DEVICE,
};
size_t payload_len = umin(*_remaining_data_length,
sp->max_send_size - sizeof(*packet));
rc = smb_extract_iter_to_rdma(iter, *_remaining_data_length,
rc = smb_extract_iter_to_rdma(iter, payload_len,
&extract);
if (rc < 0)
goto err_dma;
@@ -1013,6 +1015,27 @@ static int smbd_post_send_empty(struct smbd_connection *info)
return smbd_post_send_iter(info, NULL, &remaining_data_length);
}
static int smbd_post_send_full_iter(struct smbd_connection *info,
struct iov_iter *iter,
int *_remaining_data_length)
{
int rc = 0;
/*
* smbd_post_send_iter() respects the
* negotiated max_send_size, so we need to
* loop until the full iter is posted
*/
while (iov_iter_count(iter) > 0) {
rc = smbd_post_send_iter(info, iter, _remaining_data_length);
if (rc < 0)
break;
}
return rc;
}
/*
* Post a receive request to the transport
* The remote peer can only send data when a receive request is posted
@@ -2032,14 +2055,14 @@ int smbd_send(struct TCP_Server_Info *server,
klen += rqst->rq_iov[i].iov_len;
iov_iter_kvec(&iter, ITER_SOURCE, rqst->rq_iov, rqst->rq_nvec, klen);
rc = smbd_post_send_iter(info, &iter, &remaining_data_length);
rc = smbd_post_send_full_iter(info, &iter, &remaining_data_length);
if (rc < 0)
break;
if (iov_iter_count(&rqst->rq_iter) > 0) {
/* And then the data pages if there are any */
rc = smbd_post_send_iter(info, &rqst->rq_iter,
&remaining_data_length);
rc = smbd_post_send_full_iter(info, &rqst->rq_iter,
&remaining_data_length);
if (rc < 0)
break;
}