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libata: use WARN_ON_ONCE on hot paths
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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>
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Tejun Heo authored and Linus Torvalds committed Jan 9, 2009
1 parent 43529c9 commit efcb3cf
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Showing 2 changed files with 20 additions and 20 deletions.
16 changes: 8 additions & 8 deletions drivers/ata/libata-core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down Expand Up @@ -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;
Expand All @@ -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);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down
24 changes: 12 additions & 12 deletions drivers/ata/libata-sff.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -1014,7 +1014,7 @@ static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
}

/* 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;
Expand Down Expand Up @@ -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",
Expand Down Expand Up @@ -1387,7 +1387,7 @@ int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
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;

Expand Down Expand Up @@ -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.
Expand Down Expand Up @@ -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 */
Expand Down Expand Up @@ -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 */
Expand All @@ -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;
}

Expand Down

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