From: Tejun Heo Date: Mon, 15 May 2006 11:57:32 +0000 (+0900) Subject: [PATCH] libata: clear ap->active_tag atomically w.r.t. command completion X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=7401abf2f44695ef44eef47d5deba1c20214a063;p=openwrt%2Fstaging%2Fblogic.git [PATCH] libata: clear ap->active_tag atomically w.r.t. command completion ap->active_tag was cleared in ata_qc_free(). This left ap->active_tag dangling after ata_qc_complete(). Spurious interrupts inbetween could incorrectly access the qc. Clear active_tag in ata_qc_complete(). This change is necessary for later EH changes. Signed-off-by: Tejun Heo --- diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index 1669dae53ce3..86cd0e0895d0 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -4083,8 +4083,6 @@ void ata_qc_free(struct ata_queued_cmd *qc) qc->flags = 0; tag = qc->tag; if (likely(ata_tag_valid(tag))) { - if (tag == ap->active_tag) - ap->active_tag = ATA_TAG_POISON; qc->tag = ATA_TAG_POISON; clear_bit(tag, &ap->qactive); } @@ -4098,6 +4096,9 @@ void __ata_qc_complete(struct ata_queued_cmd *qc) if (likely(qc->flags & ATA_QCFLAG_DMAMAP)) ata_sg_clean(qc); + /* command should be marked inactive atomically with qc completion */ + qc->ap->active_tag = ATA_TAG_POISON; + /* atapi: mark qc as inactive to prevent the interrupt handler * from completing the command twice later, before the error handler * is called. (when rc != 0 and atapi request sense is needed)