From cacaead301f6371dc869b89b0125ad91aec267be Mon Sep 17 00:00:00 2001
From: sos <sos@FreeBSD.org>
Date: Thu, 23 Feb 2006 20:15:22 +0000
Subject: [PATCH] Keep the parent device (in this case the channel) around in
 ata_request, so we dont panic device removal or failure. Clean up
 ata_fail_requests to prevent the queue munging to fail.

---
 sys/dev/ata/ata-all.h   |  1 +
 sys/dev/ata/ata-queue.c | 43 +++++++++++++++++++++++++----------------
 2 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/sys/dev/ata/ata-all.h b/sys/dev/ata/ata-all.h
index 670c580d8cda..1b98e0407389 100644
--- a/sys/dev/ata/ata-all.h
+++ b/sys/dev/ata/ata-all.h
@@ -338,6 +338,7 @@ struct ata_composite {
 /* structure used to queue an ATA/ATAPI request */
 struct ata_request {
     device_t                    dev;            /* device handle */
+    device_t                    parent;         /* channel handle */
     union {
 	struct {
 	    u_int8_t            command;        /* command reg */
diff --git a/sys/dev/ata/ata-queue.c b/sys/dev/ata/ata-queue.c
index da590f49868b..e7116fe82fb5 100644
--- a/sys/dev/ata/ata-queue.c
+++ b/sys/dev/ata/ata-queue.c
@@ -55,6 +55,7 @@ ata_queue_request(struct ata_request *request)
 
     /* mark request as virgin (this might be a ATA_R_REQUEUE) */
     request->result = request->status = request->error = 0;
+    request->parent = device_get_parent(request->dev);
     callout_init_mtx(&request->callout, &ch->state_mtx, CALLOUT_RETURNUNLOCKED);
 
     if (!request->callback && !(request->flags & ATA_R_REQUEUE))
@@ -218,7 +219,7 @@ ata_start(device_t dev)
 void
 ata_finish(struct ata_request *request)
 {
-    struct ata_channel *ch = device_get_softc(device_get_parent(request->dev));
+    struct ata_channel *ch = device_get_softc(request->parent);
 
     /*
      * if in ATA_STALL_QUEUE state or request has ATA_R_DIRECT flags set
@@ -247,7 +248,7 @@ static void
 ata_completed(void *context, int dummy)
 {
     struct ata_request *request = (struct ata_request *)context;
-    struct ata_channel *ch = device_get_softc(device_get_parent(request->dev));
+    struct ata_channel *ch = device_get_softc(request->parent);
     struct ata_device *atadev = device_get_softc(request->dev);
     struct ata_composite *composite;
 
@@ -466,7 +467,7 @@ ata_completed(void *context, int dummy)
 void
 ata_timeout(struct ata_request *request)
 {
-    struct ata_channel *ch = device_get_softc(device_get_parent(request->dev));
+    struct ata_channel *ch = device_get_softc(request->parent);
 
     //request->flags |= ATA_R_DEBUG;
     ATA_DEBUG_RQ(request, "timeout");
@@ -479,7 +480,6 @@ ata_timeout(struct ata_request *request)
      */
     if (ch->state == ATA_ACTIVE) {
 	request->flags |= ATA_R_TIMEOUT;
-	ch->running = NULL;
 	mtx_unlock(&ch->state_mtx);
 	ATA_LOCKING(ch->dev, ATA_LF_UNLOCK);
 	ata_finish(request);
@@ -493,34 +493,43 @@ void
 ata_fail_requests(device_t dev)
 {
     struct ata_channel *ch = device_get_softc(device_get_parent(dev));
-    struct ata_request *request;
+    struct ata_request *request, *tmp;
+    TAILQ_HEAD(, ata_request) fail_requests;
+    TAILQ_INIT(&fail_requests);
 
-    /* do we have any outstanding request to care about ?*/
+    /* grap all channel locks to avoid races */
+    mtx_lock(&ch->queue_mtx);
     mtx_lock(&ch->state_mtx);
+
+    /* do we have any running request to care about ? */
     if ((request = ch->running) && (!dev || request->dev == dev)) {
 	callout_stop(&request->callout);
 	ch->running = NULL;
-    }
-    else
-	request = NULL;
-    mtx_unlock(&ch->state_mtx);
-    if (request)  {
+	ch->state = ATA_IDLE;
 	request->result = ENXIO;
-	ata_finish(request);
+	TAILQ_INSERT_TAIL(&fail_requests, request, chain);
     }
 
     /* fail all requests queued on this channel for device dev if !NULL */
-    mtx_lock(&ch->queue_mtx);
-    while ((request = TAILQ_FIRST(&ch->ata_queue))) {
+    TAILQ_FOREACH_SAFE(request, &ch->ata_queue, chain, tmp) {
 	if (!dev || request->dev == dev) {
 	    TAILQ_REMOVE(&ch->ata_queue, request, chain);
-	    mtx_unlock(&ch->queue_mtx);
 	    request->result = ENXIO;
-	    ata_finish(request);
-	    mtx_lock(&ch->queue_mtx);
+	    TAILQ_INSERT_TAIL(&fail_requests, request, chain);
 	}
     }
+
+    mtx_unlock(&ch->state_mtx);
     mtx_unlock(&ch->queue_mtx);
+   
+    /* finish up all requests collected above */
+    TAILQ_FOREACH_SAFE(request, &fail_requests, chain, tmp) {
+        TAILQ_REMOVE(&fail_requests, request, chain);
+        ata_finish(request);
+    }
+
+    /* we might have work for the other device on this channel */
+    ata_start(ch->dev);
 }
 
 static u_int64_t