From: Vasu Dev <vasu.dev@xxxxxxxxx> Currently the fc_exch_rrq is called with fc_exch's ex_lock held. The fc_exch_rrq allocates new exch and that requires taking ex_lock again after EM lock. This locking order causes warning, see more details on this warning at :- http://www.open-fcoe.org/pipermail/devel/2009-July/003251.html This patch fixes this by dropping the ex_lock before calling fc_exch_rrq(). The fc_exch_rrq needs to grab ex_lock lock again to schedule RRQ retry and in the meanwhile fc_exch_reset could occur before ex_lock is grabbed inside fc_exch_rrq. So to handle this case, this patch adds additional check to detect fc_exch_reset after ex_lock acquired and in case the fc_exch_reset occurred then abandons the RRQ retry and releases the exch. Signed-off-by: Vasu Dev <vasu.dev@xxxxxxxxx> Signed-off-by: Robert Love <robert.w.love@xxxxxxxxx> --- drivers/scsi/libfc/fc_exch.c | 23 +++++++++++++++-------- 1 files changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c index 2bc22be..145ab9b 100644 --- a/drivers/scsi/libfc/fc_exch.c +++ b/drivers/scsi/libfc/fc_exch.c @@ -415,9 +415,9 @@ static void fc_exch_timeout(struct work_struct *work) e_stat = ep->esb_stat; if (e_stat & ESB_ST_COMPLETE) { ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL; + spin_unlock_bh(&ep->ex_lock); if (e_stat & ESB_ST_REC_QUAL) fc_exch_rrq(ep); - spin_unlock_bh(&ep->ex_lock); goto done; } else { resp = ep->resp; @@ -1624,14 +1624,14 @@ static void fc_exch_rrq(struct fc_exch *ep) struct fc_lport *lp; struct fc_els_rrq *rrq; struct fc_frame *fp; - struct fc_seq *rrq_sp; u32 did; lp = ep->lp; fp = fc_frame_alloc(lp, sizeof(*rrq)); if (!fp) - return; + goto retry; + rrq = fc_frame_payload_get(fp, sizeof(*rrq)); memset(rrq, 0, sizeof(*rrq)); rrq->rrq_cmd = ELS_RRQ; @@ -1647,13 +1647,20 @@ static void fc_exch_rrq(struct fc_exch *ep) fc_host_port_id(lp->host), FC_TYPE_ELS, FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); - rrq_sp = fc_exch_seq_send(lp, fp, fc_exch_rrq_resp, NULL, ep, - lp->e_d_tov); - if (!rrq_sp) { - ep->esb_stat |= ESB_ST_REC_QUAL; - fc_exch_timer_set_locked(ep, ep->r_a_tov); + if (fc_exch_seq_send(lp, fp, fc_exch_rrq_resp, NULL, ep, lp->e_d_tov)) + return; + +retry: + spin_lock_bh(&ep->ex_lock); + if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) { + spin_unlock_bh(&ep->ex_lock); + /* drop hold for rec qual */ + fc_exch_release(ep); return; } + ep->esb_stat |= ESB_ST_REC_QUAL; + fc_exch_timer_set_locked(ep, ep->r_a_tov); + spin_unlock_bh(&ep->ex_lock); } -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
