Re: [RFC PATCH] lpfc: Add lockdep assertions

[James Smart <james.smart@avagotech.com>]

Johannes,

Thank you for the time and effort on the patch. At this time, as it 
doesn't functionally change anything, I did not include the patch. I 
will consider it if we see additional issues it can help resolve.

-- james s


On 11/20/2015 4:37 AM, Johannes Thumshirn wrote:
> Several functions in lpfc have comments stating that the function must be
> called with the hbalock (or hostlock, or ringlock) held. Add
> lockdep_assert_held() annotations to these functions, so one can actually
> verify the locks are held.
>
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---
>
> I'm not sure if this is actually helpfull upstream but it helped me to debug a
> downstream bug.
>
>   drivers/scsi/lpfc/lpfc_hbadisc.c |  5 +++++
>   drivers/scsi/lpfc/lpfc_sli.c     | 43 ++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 48 insertions(+)
>
> diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
> index bfc2442..96de2ab 100644
> --- a/drivers/scsi/lpfc/lpfc_hbadisc.c
> +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
> @@ -25,6 +25,7 @@
>   #include <linux/pci.h>
>   #include <linux/kthread.h>
>   #include <linux/interrupt.h>
> +#include <linux/lockdep.h>
>   
>   #include <scsi/scsi.h>
>   #include <scsi/scsi_device.h>
> @@ -1314,6 +1315,8 @@ __lpfc_update_fcf_record_pri(struct lpfc_hba *phba, uint16_t fcf_index,
>   {
>   	struct lpfc_fcf_pri *fcf_pri;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	fcf_pri = &phba->fcf.fcf_pri[fcf_index];
>   	fcf_pri->fcf_rec.fcf_index = fcf_index;
>   	/* FCF record priority */
> @@ -1398,6 +1401,8 @@ __lpfc_update_fcf_record(struct lpfc_hba *phba, struct lpfc_fcf_rec *fcf_rec,
>   		       struct fcf_record *new_fcf_record, uint32_t addr_mode,
>   		       uint16_t vlan_id, uint32_t flag)
>   {
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	/* Copy the fields from the HBA's FCF record */
>   	lpfc_copy_fcf_record(fcf_rec, new_fcf_record);
>   	/* Update other fields of driver FCF record */
> diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
> index f9585cd..6d84c77 100644
> --- a/drivers/scsi/lpfc/lpfc_sli.c
> +++ b/drivers/scsi/lpfc/lpfc_sli.c
> @@ -24,6 +24,7 @@
>   #include <linux/interrupt.h>
>   #include <linux/delay.h>
>   #include <linux/slab.h>
> +#include <linux/lockdep.h>
>   
>   #include <scsi/scsi.h>
>   #include <scsi/scsi_cmnd.h>
> @@ -576,6 +577,8 @@ __lpfc_sli_get_iocbq(struct lpfc_hba *phba)
>   	struct list_head *lpfc_iocb_list = &phba->lpfc_iocb_list;
>   	struct lpfc_iocbq * iocbq = NULL;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	list_remove_head(lpfc_iocb_list, iocbq, struct lpfc_iocbq, list);
>   	if (iocbq)
>   		phba->iocb_cnt++;
> @@ -797,6 +800,7 @@ int
>   lpfc_test_rrq_active(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp,
>   			uint16_t  xritag)
>   {
> +	lockdep_assert_held(&phba->hbalock);
>   	if (!ndlp)
>   		return 0;
>   	if (!ndlp->active_rrqs_xri_bitmap)
> @@ -914,6 +918,8 @@ __lpfc_sli_get_sglq(struct lpfc_hba *phba, struct lpfc_iocbq *piocbq)
>   	struct lpfc_nodelist *ndlp;
>   	int found = 0;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	if (piocbq->iocb_flag &  LPFC_IO_FCP) {
>   		lpfc_cmd = (struct lpfc_scsi_buf *) piocbq->context1;
>   		ndlp = lpfc_cmd->rdata->pnode;
> @@ -1003,6 +1009,8 @@ __lpfc_sli_release_iocbq_s4(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq)
>   	unsigned long iflag = 0;
>   	struct lpfc_sli_ring *pring = &phba->sli.ring[LPFC_ELS_RING];
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	if (iocbq->sli4_xritag == NO_XRI)
>   		sglq = NULL;
>   	else
> @@ -1058,6 +1066,7 @@ __lpfc_sli_release_iocbq_s3(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq)
>   {
>   	size_t start_clean = offsetof(struct lpfc_iocbq, iocb);
>   
> +	lockdep_assert_held(&phba->hbalock);
>   
>   	/*
>   	 * Clean all volatile data fields, preserve iotag and node struct.
> @@ -1080,6 +1089,8 @@ __lpfc_sli_release_iocbq_s3(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq)
>   static void
>   __lpfc_sli_release_iocbq(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq)
>   {
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	phba->__lpfc_sli_release_iocbq(phba, iocbq);
>   	phba->iocb_cnt--;
>   }
> @@ -1310,6 +1321,8 @@ static int
>   lpfc_sli_ringtxcmpl_put(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,
>   			struct lpfc_iocbq *piocb)
>   {
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	list_add_tail(&piocb->list, &pring->txcmplq);
>   	piocb->iocb_flag |= LPFC_IO_ON_TXCMPLQ;
>   
> @@ -1344,6 +1357,8 @@ lpfc_sli_ringtx_get(struct lpfc_hba *phba, struct lpfc_sli_ring *pring)
>   {
>   	struct lpfc_iocbq *cmd_iocb;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	list_remove_head((&pring->txq), cmd_iocb, struct lpfc_iocbq, list);
>   	return cmd_iocb;
>   }
> @@ -1367,6 +1382,9 @@ lpfc_sli_next_iocb_slot (struct lpfc_hba *phba, struct lpfc_sli_ring *pring)
>   {
>   	struct lpfc_pgp *pgp = &phba->port_gp[pring->ringno];
>   	uint32_t  max_cmd_idx = pring->sli.sli3.numCiocb;
> +
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	if ((pring->sli.sli3.next_cmdidx == pring->sli.sli3.cmdidx) &&
>   	   (++pring->sli.sli3.next_cmdidx >= max_cmd_idx))
>   		pring->sli.sli3.next_cmdidx = 0;
> @@ -1497,6 +1515,7 @@ static void
>   lpfc_sli_submit_iocb(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,
>   		IOCB_t *iocb, struct lpfc_iocbq *nextiocb)
>   {
> +	lockdep_assert_held(&phba->hbalock);
>   	/*
>   	 * Set up an iotag
>   	 */
> @@ -1606,6 +1625,8 @@ lpfc_sli_resume_iocb(struct lpfc_hba *phba, struct lpfc_sli_ring *pring)
>   	IOCB_t *iocb;
>   	struct lpfc_iocbq *nextiocb;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	/*
>   	 * Check to see if:
>   	 *  (a) there is anything on the txq to send
> @@ -1647,6 +1668,8 @@ lpfc_sli_next_hbq_slot(struct lpfc_hba *phba, uint32_t hbqno)
>   {
>   	struct hbq_s *hbqp = &phba->hbqs[hbqno];
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	if (hbqp->next_hbqPutIdx == hbqp->hbqPutIdx &&
>   	    ++hbqp->next_hbqPutIdx >= hbqp->entry_count)
>   		hbqp->next_hbqPutIdx = 0;
> @@ -1747,6 +1770,7 @@ static int
>   lpfc_sli_hbq_to_firmware(struct lpfc_hba *phba, uint32_t hbqno,
>   			 struct hbq_dmabuf *hbq_buf)
>   {
> +	lockdep_assert_held(&phba->hbalock);
>   	return phba->lpfc_sli_hbq_to_firmware(phba, hbqno, hbq_buf);
>   }
>   
> @@ -1768,6 +1792,7 @@ lpfc_sli_hbq_to_firmware_s3(struct lpfc_hba *phba, uint32_t hbqno,
>   	struct lpfc_hbq_entry *hbqe;
>   	dma_addr_t physaddr = hbq_buf->dbuf.phys;
>   
> +	lockdep_assert_held(&phba->hbalock);
>   	/* Get next HBQ entry slot to use */
>   	hbqe = lpfc_sli_next_hbq_slot(phba, hbqno);
>   	if (hbqe) {
> @@ -1808,6 +1833,7 @@ lpfc_sli_hbq_to_firmware_s4(struct lpfc_hba *phba, uint32_t hbqno,
>   	struct lpfc_rqe hrqe;
>   	struct lpfc_rqe drqe;
>   
> +	lockdep_assert_held(&phba->hbalock);
>   	hrqe.address_lo = putPaddrLow(hbq_buf->hbuf.phys);
>   	hrqe.address_hi = putPaddrHigh(hbq_buf->hbuf.phys);
>   	drqe.address_lo = putPaddrLow(hbq_buf->dbuf.phys);
> @@ -1986,6 +2012,8 @@ lpfc_sli_hbqbuf_find(struct lpfc_hba *phba, uint32_t tag)
>   	struct hbq_dmabuf *hbq_buf;
>   	uint32_t hbqno;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	hbqno = tag >> 16;
>   	if (hbqno >= LPFC_MAX_HBQS)
>   		return NULL;
> @@ -2647,6 +2675,7 @@ lpfc_sli_iocbq_lookup(struct lpfc_hba *phba,
>   {
>   	struct lpfc_iocbq *cmd_iocb = NULL;
>   	uint16_t iotag;
> +	lockdep_assert_held(&phba->hbalock);
>   
>   	iotag = prspiocb->iocb.ulpIoTag;
>   
> @@ -2685,6 +2714,7 @@ lpfc_sli_iocbq_lookup_by_tag(struct lpfc_hba *phba,
>   {
>   	struct lpfc_iocbq *cmd_iocb;
>   
> +	lockdep_assert_held(&phba->hbalock);
>   	if (iotag != 0 && iotag <= phba->sli.last_iotag) {
>   		cmd_iocb = phba->sli.iocbq_lookup[iotag];
>   		if (cmd_iocb->iocb_flag & LPFC_IO_ON_TXCMPLQ) {
> @@ -3799,6 +3829,8 @@ void lpfc_reset_barrier(struct lpfc_hba *phba)
>   	int  i;
>   	uint8_t hdrtype;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	pci_read_config_byte(phba->pcidev, PCI_HEADER_TYPE, &hdrtype);
>   	if (hdrtype != 0x80 ||
>   	    (FC_JEDEC_ID(phba->vpd.rev.biuRev) != HELIOS_JEDEC_ID &&
> @@ -7861,6 +7893,7 @@ void
>   __lpfc_sli_ringtx_put(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,
>   		    struct lpfc_iocbq *piocb)
>   {
> +	lockdep_assert_held(&phba->hbalock);
>   	/* Insert the caller's iocb in the txq tail for later processing. */
>   	list_add_tail(&piocb->list, &pring->txq);
>   }
> @@ -7888,6 +7921,8 @@ lpfc_sli_next_iocb(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,
>   {
>   	struct lpfc_iocbq * nextiocb;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	nextiocb = lpfc_sli_ringtx_get(phba, pring);
>   	if (!nextiocb) {
>   		nextiocb = *piocb;
> @@ -7927,6 +7962,8 @@ __lpfc_sli_issue_iocb_s3(struct lpfc_hba *phba, uint32_t ring_number,
>   	IOCB_t *iocb;
>   	struct lpfc_sli_ring *pring = &phba->sli.ring[ring_number];
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	if (piocb->iocb_cmpl && (!piocb->vport) &&
>   	   (piocb->iocb.ulpCommand != CMD_ABORT_XRI_CN) &&
>   	   (piocb->iocb.ulpCommand != CMD_CLOSE_XRI_CN)) {
> @@ -8642,6 +8679,8 @@ __lpfc_sli_issue_iocb_s4(struct lpfc_hba *phba, uint32_t ring_number,
>   	struct lpfc_queue *wq;
>   	struct lpfc_sli_ring *pring = &phba->sli.ring[ring_number];
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	if (piocb->sli4_xritag == NO_XRI) {
>   		if (piocb->iocb.ulpCommand == CMD_ABORT_XRI_CN ||
>   		    piocb->iocb.ulpCommand == CMD_CLOSE_XRI_CN)
> @@ -9752,6 +9791,8 @@ lpfc_sli_abort_iotag_issue(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,
>   	int retval;
>   	unsigned long iflags;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	/*
>   	 * There are certain command types we don't want to abort.  And we
>   	 * don't want to abort commands that are already in the process of
> @@ -9854,6 +9895,8 @@ lpfc_sli_issue_abort_iotag(struct lpfc_hba *phba, struct lpfc_sli_ring *pring,
>   	int retval = IOCB_ERROR;
>   	IOCB_t *icmd = NULL;
>   
> +	lockdep_assert_held(&phba->hbalock);
> +
>   	/*
>   	 * There are certain command types we don't want to abort.  And we
>   	 * don't want to abort commands that are already in the process of