From d576a5e80cd07ea7049f8fd7b303c14df7b5d7d2 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Mon, 23 Jun 2014 10:41:02 -0400 Subject: [PATCH] bnx2fc: Improve stats update mechanism Recently had this warning reported: [ 290.489047] Call Trace: [ 290.489053] [] dump_stack+0x19/0x1b [ 290.489055] [] __might_sleep+0x179/0x230 [ 290.489057] [] mutex_lock_nested+0x55/0x520 [ 290.489061] [] ? bnx2fc_l2_rcv_thread+0xc5/0x4c0 [bnx2fc] [ 290.489065] [] fc_vport_id_lookup+0x3a/0xa0 [libfc] [ 290.489068] [] bnx2fc_l2_rcv_thread+0x22c/0x4c0 [bnx2fc] [ 290.489070] [] ? bnx2fc_vport_destroy+0x110/0x110 [bnx2fc] [ 290.489073] [] kthread+0xed/0x100 [ 290.489075] [] ? insert_kthread_work+0x80/0x80 [ 290.489077] [] ret_from_fork+0x7c/0xb0 [ 290.489078] [] ? insert_kthread_work+0x80/0x80 Its due to the fact that we call a potentially sleeping function from the bnx2fc rcv path with preemption disabled (via the get_cpu call embedded in the per-cpu variable stats lookup in bnx2fc_l2_rcv_thread. Easy enough fix, we can just move the stats collection later in the function where we are sure we won't preempt or sleep. This also allows us to not have to enable pre-emption when doing a per-cpu lookup, since we're certain not to get rescheduled. Signed-off-by: Neil Horman Acked-by: Eddie Wai Signed-off-by: Christoph Hellwig --- drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c index f548430..785d0d7 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c @@ -516,23 +516,17 @@ static void bnx2fc_recv_frame(struct sk_buff *skb) skb_pull(skb, sizeof(struct fcoe_hdr)); fr_len = skb->len - sizeof(struct fcoe_crc_eof); - stats = per_cpu_ptr(lport->stats, get_cpu()); - stats->RxFrames++; - stats->RxWords += fr_len / FCOE_WORD_TO_BYTE; - fp = (struct fc_frame *)skb; fc_frame_init(fp); fr_dev(fp) = lport; fr_sof(fp) = hp->fcoe_sof; if (skb_copy_bits(skb, fr_len, &crc_eof, sizeof(crc_eof))) { - put_cpu(); kfree_skb(skb); return; } fr_eof(fp) = crc_eof.fcoe_eof; fr_crc(fp) = crc_eof.fcoe_crc32; if (pskb_trim(skb, fr_len)) { - put_cpu(); kfree_skb(skb); return; } @@ -544,7 +538,6 @@ static void bnx2fc_recv_frame(struct sk_buff *skb) port = lport_priv(vn_port); if (!ether_addr_equal(port->data_src_addr, dest_mac)) { BNX2FC_HBA_DBG(lport, "fpma mismatch\n"); - put_cpu(); kfree_skb(skb); return; } @@ -552,7 +545,6 @@ static void bnx2fc_recv_frame(struct sk_buff *skb) if (fh->fh_r_ctl == FC_RCTL_DD_SOL_DATA && fh->fh_type == FC_TYPE_FCP) { /* Drop FCP data. We dont this in L2 path */ - put_cpu(); kfree_skb(skb); return; } @@ -562,7 +554,6 @@ static void bnx2fc_recv_frame(struct sk_buff *skb) case ELS_LOGO: if (ntoh24(fh->fh_s_id) == FC_FID_FLOGI) { /* drop non-FIP LOGO */ - put_cpu(); kfree_skb(skb); return; } @@ -572,22 +563,23 @@ static void bnx2fc_recv_frame(struct sk_buff *skb) if (fh->fh_r_ctl == FC_RCTL_BA_ABTS) { /* Drop incoming ABTS */ - put_cpu(); kfree_skb(skb); return; } + stats = per_cpu_ptr(lport->stats, smp_processor_id()); + stats->RxFrames++; + stats->RxWords += fr_len / FCOE_WORD_TO_BYTE; + if (le32_to_cpu(fr_crc(fp)) != ~crc32(~0, skb->data, fr_len)) { if (stats->InvalidCRCCount < 5) printk(KERN_WARNING PFX "dropping frame with " "CRC error\n"); stats->InvalidCRCCount++; - put_cpu(); kfree_skb(skb); return; } - put_cpu(); fc_exch_recv(lport, fp); } -- 2.7.4