From d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 Mon Sep 17 00:00:00 2001 From: Shyam Prasad N Date: Wed, 27 Jul 2022 14:49:56 -0500 Subject: cifs: avoid use of global locks for high contention data During analysis of multichannel perf, it was seen that the global locks cifs_tcp_ses_lock and GlobalMid_Lock, which were shared between various data structures were causing a lot of contention points. With this change, we're breaking down the use of these locks by introducing new locks at more granular levels. i.e. server->srv_lock, ses->ses_lock and tcon->tc_lock to protect the unprotected fields of server, session and tcon structs; and server->mid_lock to protect mid related lists and entries at server level. Signed-off-by: Shyam Prasad N Signed-off-by: Steve French --- fs/cifs/smb2ops.c | 47 ++++++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 21 deletions(-) (limited to 'fs/cifs/smb2ops.c') diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 5bed8b584086..82dd2e973753 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -126,13 +126,13 @@ smb2_add_credits(struct TCP_Server_Info *server, optype, scredits, add); } - spin_lock(&cifs_tcp_ses_lock); + spin_lock(&server->srv_lock); if (server->tcpStatus == CifsNeedReconnect || server->tcpStatus == CifsExiting) { - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&server->srv_lock); return; } - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&server->srv_lock); switch (rc) { case -1: @@ -218,12 +218,12 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size, spin_lock(&server->req_lock); } else { spin_unlock(&server->req_lock); - spin_lock(&cifs_tcp_ses_lock); + spin_lock(&server->srv_lock); if (server->tcpStatus == CifsExiting) { - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&server->srv_lock); return -ENOENT; } - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&server->srv_lock); spin_lock(&server->req_lock); scredits = server->credits; @@ -319,19 +319,19 @@ smb2_get_next_mid(struct TCP_Server_Info *server) { __u64 mid; /* for SMB2 we need the current value */ - spin_lock(&GlobalMid_Lock); + spin_lock(&server->mid_lock); mid = server->CurrentMid++; - spin_unlock(&GlobalMid_Lock); + spin_unlock(&server->mid_lock); return mid; } static void smb2_revert_current_mid(struct TCP_Server_Info *server, const unsigned int val) { - spin_lock(&GlobalMid_Lock); + spin_lock(&server->mid_lock); if (server->CurrentMid >= val) server->CurrentMid -= val; - spin_unlock(&GlobalMid_Lock); + spin_unlock(&server->mid_lock); } static struct mid_q_entry * @@ -346,7 +346,7 @@ __smb2_find_mid(struct TCP_Server_Info *server, char *buf, bool dequeue) return NULL; } - spin_lock(&GlobalMid_Lock); + spin_lock(&server->mid_lock); list_for_each_entry(mid, &server->pending_mid_q, qhead) { if ((mid->mid == wire_mid) && (mid->mid_state == MID_REQUEST_SUBMITTED) && @@ -356,11 +356,11 @@ __smb2_find_mid(struct TCP_Server_Info *server, char *buf, bool dequeue) list_del_init(&mid->qhead); mid->mid_flags |= MID_DELETED; } - spin_unlock(&GlobalMid_Lock); + spin_unlock(&server->mid_lock); return mid; } } - spin_unlock(&GlobalMid_Lock); + spin_unlock(&server->mid_lock); return NULL; } @@ -403,9 +403,9 @@ smb2_negotiate(const unsigned int xid, { int rc; - spin_lock(&GlobalMid_Lock); + spin_lock(&server->mid_lock); server->CurrentMid = 0; - spin_unlock(&GlobalMid_Lock); + spin_unlock(&server->mid_lock); rc = SMB2_negotiate(xid, ses, server); /* BB we probably don't need to retry with modern servers */ if (rc == -EAGAIN) @@ -2585,7 +2585,9 @@ smb2_is_network_name_deleted(char *buf, struct TCP_Server_Info *server) list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { if (tcon->tid == le32_to_cpu(shdr->Id.SyncId.TreeId)) { + spin_lock(&tcon->tc_lock); tcon->need_reconnect = true; + spin_unlock(&tcon->tc_lock); spin_unlock(&cifs_tcp_ses_lock); pr_warn_once("Server share %s deleted.\n", tcon->treeName); @@ -4561,9 +4563,11 @@ smb2_get_enc_key(struct TCP_Server_Info *server, __u64 ses_id, int enc, u8 *key) list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) { list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { if (ses->Suid == ses_id) { + spin_lock(&ses->ses_lock); ses_enc_key = enc ? ses->smb3encryptionkey : ses->smb3decryptionkey; memcpy(key, ses_enc_key, SMB3_ENC_DEC_KEY_SIZE); + spin_unlock(&ses->ses_lock); spin_unlock(&cifs_tcp_ses_lock); return 0; } @@ -5078,20 +5082,21 @@ static void smb2_decrypt_offload(struct work_struct *work) mid->callback(mid); } else { - spin_lock(&cifs_tcp_ses_lock); - spin_lock(&GlobalMid_Lock); + spin_lock(&dw->server->srv_lock); if (dw->server->tcpStatus == CifsNeedReconnect) { + spin_lock(&dw->server->mid_lock); mid->mid_state = MID_RETRY_NEEDED; - spin_unlock(&GlobalMid_Lock); - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&dw->server->mid_lock); + spin_unlock(&dw->server->srv_lock); mid->callback(mid); } else { + spin_lock(&dw->server->mid_lock); mid->mid_state = MID_REQUEST_SUBMITTED; mid->mid_flags &= ~(MID_DELETED); list_add_tail(&mid->qhead, &dw->server->pending_mid_q); - spin_unlock(&GlobalMid_Lock); - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&dw->server->mid_lock); + spin_unlock(&dw->server->srv_lock); } } cifs_mid_q_entry_release(mid); -- cgit v1.2.3