ksmbd: improve credits management

Message ID	20211005100026.250280-1-hyc.lee@gmail.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-cifs-owner@kernel.org> From: Hyunchul Lee <hyc.lee@gmail.com> To: linux-cifs@vger.kernel.org Cc: Namjae Jeon <linkinjeon@kernel.org>, Sergey Senozhatsky <senozhatsky@chromium.org>, Steve French <smfrench@gmail.com>, Ralph Boehme <slow@samba.org>, Hyunchul Lee <hyc.lee@gmail.com> Subject: [PATCH] ksmbd: improve credits management Date: Tue, 5 Oct 2021 19:00:26 +0900 Message-Id: <20211005100026.250280-1-hyc.lee@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	ksmbd: improve credits management \| expand ksmbd: improve credits management

diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c index 9aa46bb3e10d..cbbea6937816 100644 --- a/fs/ksmbd/smb2misc.c +++ b/fs/ksmbd/smb2misc.c @@ -287,11 +287,13 @@ static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h) le32_to_cpu(h->MaxOutputResponse); } -static int smb2_validate_credit_charge(struct smb2_hdr *hdr) +static int smb2_validate_credit_charge(struct ksmbd_conn *conn, + struct smb2_hdr *hdr) { - int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len; - int credit_charge = le16_to_cpu(hdr->CreditCharge); + unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len; + unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge); void *__hdr = hdr; + int ret; switch (hdr->Command) { case SMB2_QUERY_INFO: @@ -313,21 +315,37 @@ static int smb2_validate_credit_charge(struct smb2_hdr *hdr) req_len = smb2_ioctl_req_len(__hdr); expect_resp_len = smb2_ioctl_resp_len(__hdr); break; - default: + case SMB2_CANCEL: return 0; + default: + req_len = 1; + break; } - credit_charge = max(1, credit_charge); - max_len = max(req_len, expect_resp_len); + credit_charge = max_t(unsigned short, credit_charge, 1); + max_len = max_t(unsigned int, req_len, expect_resp_len); calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE); if (credit_charge < calc_credit_num) { - pr_err("Insufficient credit charge, given: %d, needed: %d\n", - credit_charge, calc_credit_num); + ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n", + credit_charge, calc_credit_num); + return 1; + } else if (credit_charge > conn->max_credits) { + ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge); return 1; } - return 0; + spin_lock(&conn->credits_lock); + if (credit_charge <= conn->total_credits) { + conn->total_credits -= credit_charge; + ret = 0; + } else { + ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n", + credit_charge, conn->total_credits); + ret = 1; + } + spin_unlock(&conn->credits_lock); + return ret; } int ksmbd_smb2_check_message(struct ksmbd_work *work) @@ -386,7 +404,7 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work) } if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && - smb2_validate_credit_charge(hdr)) { + smb2_validate_credit_charge(work->conn, hdr)) { work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); return 1; } diff --git a/fs/ksmbd/smb2ops.c b/fs/ksmbd/smb2ops.c index 197473871aa4..d7919f95be40 100644 --- a/fs/ksmbd/smb2ops.c +++ b/fs/ksmbd/smb2ops.c @@ -203,6 +203,7 @@ void init_smb2_1_server(struct ksmbd_conn *conn) conn->ops = &smb2_0_server_ops; conn->cmds = smb2_0_server_cmds; conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds); + conn->total_credits = 1; conn->max_credits = SMB2_MAX_CREDITS; conn->signing_algorithm = SIGNING_ALG_HMAC_SHA256; @@ -221,6 +222,7 @@ void init_smb3_0_server(struct ksmbd_conn *conn) conn->ops = &smb3_0_server_ops; conn->cmds = smb2_0_server_cmds; conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds); + conn->total_credits = 1; conn->max_credits = SMB2_MAX_CREDITS; conn->signing_algorithm = SIGNING_ALG_AES_CMAC; @@ -246,6 +248,7 @@ void init_smb3_02_server(struct ksmbd_conn *conn) conn->ops = &smb3_0_server_ops; conn->cmds = smb2_0_server_cmds; conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds); + conn->total_credits = 1; conn->max_credits = SMB2_MAX_CREDITS; conn->signing_algorithm = SIGNING_ALG_AES_CMAC; @@ -271,6 +274,7 @@ int init_smb3_11_server(struct ksmbd_conn *conn) conn->ops = &smb3_11_server_ops; conn->cmds = smb2_0_server_cmds; conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds); + conn->total_credits = 1; conn->max_credits = SMB2_MAX_CREDITS; conn->signing_algorithm = SIGNING_ALG_AES_CMAC; diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index dcf907738610..6df0b0759d3f 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -295,22 +295,6 @@ int init_smb2_neg_rsp(struct ksmbd_work *work) return 0; } -static int smb2_consume_credit_charge(struct ksmbd_work *work, - unsigned short credit_charge) -{ - struct ksmbd_conn *conn = work->conn; - unsigned int rsp_credits = 1; - - if (!conn->total_credits) - return 0; - - if (credit_charge > 0) - rsp_credits = credit_charge; - - conn->total_credits -= rsp_credits; - return rsp_credits; -} - /** * smb2_set_rsp_credits() - set number of credits in response buffer * @work: smb work containing smb response buffer @@ -320,48 +304,51 @@ int smb2_set_rsp_credits(struct ksmbd_work *work) struct smb2_hdr *req_hdr = ksmbd_req_buf_next(work); struct smb2_hdr *hdr = ksmbd_resp_buf_next(work); struct ksmbd_conn *conn = work->conn; - unsigned short credits_requested = le16_to_cpu(req_hdr->CreditRequest); - unsigned short credit_charge = 1, credits_granted = 0; - unsigned short aux_max, aux_credits, min_credits; - int rsp_credit_charge; + unsigned short credits_requested; + unsigned short credit_charge, credits_granted = 0; + unsigned short aux_max, aux_credits; - if (hdr->Command == SMB2_CANCEL) - goto out; + if (work->send_no_response) + return 0; - /* get default minimum credits by shifting maximum credits by 4 */ - min_credits = conn->max_credits >> 4; + hdr->CreditCharge = req_hdr->CreditCharge; - if (conn->total_credits >= conn->max_credits) { + if (conn->total_credits > conn->max_credits) { + hdr->CreditRequest = 0; pr_err("Total credits overflow: %d\n", conn->total_credits); - conn->total_credits = min_credits; - } - - rsp_credit_charge = - smb2_consume_credit_charge(work, le16_to_cpu(req_hdr->CreditCharge)); - if (rsp_credit_charge < 0) return -EINVAL; + } - hdr->CreditCharge = cpu_to_le16(rsp_credit_charge); + credit_charge = max_t(unsigned short, + le16_to_cpu(req_hdr->CreditCharge), 1); + credits_requested = max_t(unsigned short, + le16_to_cpu(req_hdr->CreditRequest), 1); - if (credits_requested > 0) { + /* We must grant 0 credit for the final response of an asynchronous + * operation. + */ + if ((hdr->Flags & SMB2_FLAGS_ASYNC_COMMAND) && !work->multiRsp) { + credits_granted = 0; + } else { + /* according to smb2.credits smbtorture, Windows server + * 2016 or later grant up to 8192 credits at one. + */ aux_credits = credits_requested - 1; - aux_max = 32; if (hdr->Command == SMB2_NEGOTIATE) aux_max = 0; - aux_credits = (aux_credits < aux_max) ? aux_credits : aux_max; - credits_granted = aux_credits + credit_charge; + else + aux_max = conn->max_credits - credit_charge; + aux_credits = min_t(unsigned short, aux_credits, aux_max); + credits_granted = credit_charge + aux_credits; + + if (conn->max_credits - conn->total_credits < credits_granted) + credits_granted = conn->max_credits - + conn->total_credits; - /* if credits granted per client is getting bigger than default - * minimum credits then we should wrap it up within the limits. - */ - if ((conn->total_credits + credits_granted) > min_credits) - credits_granted = min_credits - conn->total_credits; /* * TODO: Need to adjuct CreditRequest value according to * current cpu load */ - } else if (conn->total_credits == 0) { - credits_granted = 1; } conn->total_credits += credits_granted; @@ -371,7 +358,6 @@ int smb2_set_rsp_credits(struct ksmbd_work *work) /* Update CreditRequest in last request */ hdr->CreditRequest = cpu_to_le16(work->credits_granted); } -out: ksmbd_debug(SMB, "credits: requested[%d] granted[%d] total_granted[%d]\n", credits_requested, credits_granted, @@ -692,13 +678,18 @@ int setup_async_work(struct ksmbd_work *work, void (*fn)(void **), void **arg) void smb2_send_interim_resp(struct ksmbd_work *work, __le32 status) { - struct smb2_hdr *rsp_hdr; + struct smb2_hdr *rsp_hdr = work->response_buf; + + work->multiRsp = 1; + if (status != STATUS_CANCELLED) { + spin_lock(&work->conn->credits_lock); + smb2_set_rsp_credits(work); + spin_unlock(&work->conn->credits_lock); + } - rsp_hdr = work->response_buf; smb2_set_err_rsp(work); rsp_hdr->Status = status; - work->multiRsp = 1; ksmbd_conn_write(work); rsp_hdr->Status = 0; work->multiRsp = 0; @@ -1233,6 +1224,7 @@ int smb2_handle_negotiate(struct ksmbd_work *work) conn->srv_sec_mode = le16_to_cpu(rsp->SecurityMode); ksmbd_conn_set_need_negotiate(work); + conn->total_credits = 0; err_out: if (rc < 0)

ksmbd: improve credits management

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