libata: use WARN_ON_ONCE on hot paths

Convert WARN_ON() on command issue/completion paths to WARN_ON_ONCE()
so that libata doesn't spam the machine even when one of those
conditions triggers repeatedly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 175df54eb6646c595cc23f3410d80a8eaa61eab4..c507a9ac78f475e8569d920f0b5404553fff7b90 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4556,7 +4556,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
        struct scatterlist *sg = qc->sg;
        int dir = qc->dma_dir;
 
-       WARN_ON(sg == NULL);
+       WARN_ON_ONCE(sg == NULL);
 
        VPRINTK("unmapping %u sg elements\n", qc->n_elem);
 
@@ -4776,7 +4776,7 @@ void ata_qc_free(struct ata_queued_cmd *qc)
        struct ata_port *ap = qc->ap;
        unsigned int tag;
 
-       WARN_ON(qc == NULL);    /* ata_qc_from_tag _might_ return NULL */
+       WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
 
        qc->flags = 0;
        tag = qc->tag;
@@ -4791,8 +4791,8 @@ void __ata_qc_complete(struct ata_queued_cmd *qc)
        struct ata_port *ap = qc->ap;
        struct ata_link *link = qc->dev->link;
 
-       WARN_ON(qc == NULL);    /* ata_qc_from_tag _might_ return NULL */
-       WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
+       WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
+       WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_ACTIVE));
 
        if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
                ata_sg_clean(qc);
@@ -4878,7 +4878,7 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
                struct ata_device *dev = qc->dev;
                struct ata_eh_info *ehi = &dev->link->eh_info;
 
-               WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
+               WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);
 
                if (unlikely(qc->err_mask))
                        qc->flags |= ATA_QCFLAG_FAILED;
@@ -5000,16 +5000,16 @@ void ata_qc_issue(struct ata_queued_cmd *qc)
         * check is skipped for old EH because it reuses active qc to
         * request ATAPI sense.
         */
-       WARN_ON(ap->ops->error_handler && ata_tag_valid(link->active_tag));
+       WARN_ON_ONCE(ap->ops->error_handler && ata_tag_valid(link->active_tag));
 
        if (ata_is_ncq(prot)) {
-               WARN_ON(link->sactive & (1 << qc->tag));
+               WARN_ON_ONCE(link->sactive & (1 << qc->tag));
 
                if (!link->sactive)
                        ap->nr_active_links++;
                link->sactive |= 1 << qc->tag;
        } else {
-               WARN_ON(link->sactive);
+               WARN_ON_ONCE(link->sactive);
 
                ap->nr_active_links++;
                link->active_tag = qc->tag;

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index c59ad76c84b1ebe2e3e28b7a08166ffb5f0313fd..0eae9b4535564ce8a64be5428faf9382683cf985 100644 (file)
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -578,7 +578,7 @@ void ata_sff_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
        }
 
        if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
-               WARN_ON(!ioaddr->ctl_addr);
+               WARN_ON_ONCE(!ioaddr->ctl_addr);
                iowrite8(tf->hob_feature, ioaddr->feature_addr);
                iowrite8(tf->hob_nsect, ioaddr->nsect_addr);
                iowrite8(tf->hob_lbal, ioaddr->lbal_addr);
@@ -651,7 +651,7 @@ void ata_sff_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
                        iowrite8(tf->ctl, ioaddr->ctl_addr);
                        ap->last_ctl = tf->ctl;
                } else
-                       WARN_ON(1);
+                       WARN_ON_ONCE(1);
        }
 }
 EXPORT_SYMBOL_GPL(ata_sff_tf_read);
@@ -891,7 +891,7 @@ static void ata_pio_sectors(struct ata_queued_cmd *qc)
                /* READ/WRITE MULTIPLE */
                unsigned int nsect;
 
-               WARN_ON(qc->dev->multi_count == 0);
+               WARN_ON_ONCE(qc->dev->multi_count == 0);
 
                nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
                            qc->dev->multi_count);
@@ -918,7 +918,7 @@ static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
 {
        /* send SCSI cdb */
        DPRINTK("send cdb\n");
-       WARN_ON(qc->dev->cdb_len < 12);
+       WARN_ON_ONCE(qc->dev->cdb_len < 12);
 
        ap->ops->sff_data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
        ata_sff_sync(ap);
@@ -1014,7 +1014,7 @@ next_sg:
        }
 
        /* consumed can be larger than count only for the last transfer */
-       WARN_ON(qc->cursg && count != consumed);
+       WARN_ON_ONCE(qc->cursg && count != consumed);
 
        if (bytes)
                goto next_sg;
@@ -1172,13 +1172,13 @@ int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
        unsigned long flags = 0;
        int poll_next;
 
-       WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
+       WARN_ON_ONCE((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
 
        /* Make sure ata_sff_qc_issue() does not throw things
         * like DMA polling into the workqueue. Notice that
         * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
         */
-       WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
+       WARN_ON_ONCE(in_wq != ata_hsm_ok_in_wq(ap, qc));
 
 fsm_start:
        DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
@@ -1387,7 +1387,7 @@ fsm_start:
                DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
                        ap->print_id, qc->dev->devno, status);
 
-               WARN_ON(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
+               WARN_ON_ONCE(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
 
                ap->hsm_task_state = HSM_ST_IDLE;
 
@@ -1423,7 +1423,7 @@ void ata_pio_task(struct work_struct *work)
        int poll_next;
 
 fsm_start:
-       WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
+       WARN_ON_ONCE(ap->hsm_task_state == HSM_ST_IDLE);
 
        /*
         * This is purely heuristic.  This is a fast path.
@@ -1512,7 +1512,7 @@ unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
                break;
 
        case ATA_PROT_DMA:
-               WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
+               WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
 
                ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
                ap->ops->bmdma_setup(qc);           /* set up bmdma */
@@ -1564,7 +1564,7 @@ unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
                break;
 
        case ATAPI_PROT_DMA:
-               WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
+               WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
 
                ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
                ap->ops->bmdma_setup(qc);           /* set up bmdma */
@@ -1576,7 +1576,7 @@ unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
                break;
 
        default:
-               WARN_ON(1);
+               WARN_ON_ONCE(1);
                return AC_ERR_SYSTEM;
        }