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| author | Stefan Metzmacher <metze@samba.org> | 2026-02-05 19:14:14 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2026-02-09 05:25:16 +0300 |
| commit | 4a93d1ee2d0206970b6eb13fbffe07938cd95948 (patch) | |
| tree | 8421a0335a93693892a4e78f2e7613e3aeeff3af | |
| parent | 77ffbcac4e569566d0092d5f22627dfc0896b553 (diff) | |
| download | linux-4a93d1ee2d0206970b6eb13fbffe07938cd95948.tar.xz | |
smb: client: correct value for smbd_max_fragmented_recv_size
When we download a file without rdma offload or get
a large directly enumeration from the server,
the server might want to send up to smbd_max_fragmented_recv_size
bytes, but if it is too large all our recv buffers
might already be moved to the recv_io.reassembly.list
and we're no longer able to grant recv credits.
The maximum fragmented upper-layer payload receive size supported
Assume max_payload_per_credit is
smbd_max_receive_size - 24 = 1340
The maximum number would be
smbd_receive_credit_max * max_payload_per_credit
1340 * 255 = 341700 (0x536C4)
The minimum value from the spec is 131072 (0x20000)
For now we use the logic we used in ksmbd before:
(1364 * 255) / 2 = 173910 (0x2A756)
Fixes: 03bee01d6215 ("CIFS: SMBD: Add SMB Direct protocol initial values and constants")
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/smb/client/smbdirect.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c index bb236f80b3c7..d44847c9d8fc 100644 --- a/fs/smb/client/smbdirect.c +++ b/fs/smb/client/smbdirect.c @@ -101,8 +101,23 @@ int smbd_send_credit_target = 255; /* The maximum single message size can be sent to remote peer */ int smbd_max_send_size = 1364; -/* The maximum fragmented upper-layer payload receive size supported */ -int smbd_max_fragmented_recv_size = 1024 * 1024; +/* + * The maximum fragmented upper-layer payload receive size supported + * + * Assume max_payload_per_credit is + * smbd_max_receive_size - 24 = 1340 + * + * The maximum number would be + * smbd_receive_credit_max * max_payload_per_credit + * + * 1340 * 255 = 341700 (0x536C4) + * + * The minimum value from the spec is 131072 (0x20000) + * + * For now we use the logic we used in ksmbd before: + * (1364 * 255) / 2 = 173910 (0x2A756) + */ +int smbd_max_fragmented_recv_size = (1364 * 255) / 2; /* The maximum single-message size which can be received */ int smbd_max_receive_size = 1364; |