ide: ensure atapi sense request aren't preempted

There's an issue with how sense requests are handled in IDE. If ide-cd
encounters an error, it queues a sense request. With how IDE request
handling is done, this is the next request we need to handle. But it's
impossible to guarantee this, as another request could come in between
the sense being queued, and ->queue_rq() being run and handling it. If
that request ALSO fails, then we attempt to doubly queue the single
sense request we have.

Since we only support one active request at the time, defer request
processing when a sense request is queued.

Fixes: 600335205b8d "ide: convert to blk-mq"
Reported-by: He Zhe <zhe.he@windriver.com>
Tested-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index da58020a144eebfd47c169eca77cc438e218d8c0..33a28cde126c9013b7ab38e38d21232f47571f87 100644 (file)
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -235,21 +235,28 @@ EXPORT_SYMBOL_GPL(ide_prep_sense);
 
 int ide_queue_sense_rq(ide_drive_t *drive, void *special)
 {
-       struct request *sense_rq = drive->sense_rq;
+       ide_hwif_t *hwif = drive->hwif;
+       struct request *sense_rq;
+       unsigned long flags;
+
+       spin_lock_irqsave(&hwif->lock, flags);
 
        /* deferred failure from ide_prep_sense() */
        if (!drive->sense_rq_armed) {
                printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
                       drive->name);
+               spin_unlock_irqrestore(&hwif->lock, flags);
                return -ENOMEM;
        }
 
+       sense_rq = drive->sense_rq;
        ide_req(sense_rq)->special = special;
        drive->sense_rq_armed = false;
 
        drive->hwif->rq = NULL;
 
        ide_insert_request_head(drive, sense_rq);
+       spin_unlock_irqrestore(&hwif->lock, flags);
        return 0;
 }
 EXPORT_SYMBOL_GPL(ide_queue_sense_rq);

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 8445b484ae69ed3f813860731c137a6d4b32789b..b137f27a34d585b5d1472624d9d021fee833a8f0 100644 (file)
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -68,8 +68,10 @@ int ide_end_rq(ide_drive_t *drive, struct request *rq, blk_status_t error,
        }
 
        if (!blk_update_request(rq, error, nr_bytes)) {
-               if (rq == drive->sense_rq)
+               if (rq == drive->sense_rq) {
                        drive->sense_rq = NULL;
+                       drive->sense_rq_active = false;
+               }
 
                __blk_mq_end_request(rq, error);
                return 0;
@@ -451,16 +453,11 @@ void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
                blk_mq_delay_run_hw_queue(q->queue_hw_ctx[0], 3);
 }
 
-/*
- * Issue a new request to a device.
- */
-blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
-                         const struct blk_mq_queue_data *bd)
+blk_status_t ide_issue_rq(ide_drive_t *drive, struct request *rq,
+                         bool local_requeue)
 {
-       ide_drive_t     *drive = hctx->queue->queuedata;
-       ide_hwif_t      *hwif = drive->hwif;
+       ide_hwif_t *hwif = drive->hwif;
        struct ide_host *host = hwif->host;
-       struct request  *rq = bd->rq;
        ide_startstop_t startstop;
 
        if (!blk_rq_is_passthrough(rq) && !(rq->rq_flags & RQF_DONTPREP)) {
@@ -474,8 +471,6 @@ blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
        if (ide_lock_host(host, hwif))
                return BLK_STS_DEV_RESOURCE;
 
-       blk_mq_start_request(rq);
-
        spin_lock_irq(&hwif->lock);
 
        if (!ide_lock_port(hwif)) {
@@ -510,18 +505,6 @@ repeat:
                hwif->cur_dev = drive;
                drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
 
-               /*
-                * we know that the queue isn't empty, but this can happen
-                * if ->prep_rq() decides to kill a request
-                */
-               if (!rq) {
-                       rq = bd->rq;
-                       if (!rq) {
-                               ide_unlock_port(hwif);
-                               goto out;
-                       }
-               }
-
                /*
                 * Sanity: don't accept a request that isn't a PM request
                 * if we are currently power managed. This is very important as
@@ -560,9 +543,12 @@ repeat:
                }
        } else {
 plug_device:
+               if (local_requeue)
+                       list_add(&rq->queuelist, &drive->rq_list);
                spin_unlock_irq(&hwif->lock);
                ide_unlock_host(host);
-               ide_requeue_and_plug(drive, rq);
+               if (!local_requeue)
+                       ide_requeue_and_plug(drive, rq);
                return BLK_STS_OK;
        }
 
@@ -573,6 +559,26 @@ out:
        return BLK_STS_OK;
 }
 
+/*
+ * Issue a new request to a device.
+ */
+blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
+                         const struct blk_mq_queue_data *bd)
+{
+       ide_drive_t *drive = hctx->queue->queuedata;
+       ide_hwif_t *hwif = drive->hwif;
+
+       spin_lock_irq(&hwif->lock);
+       if (drive->sense_rq_active) {
+               spin_unlock_irq(&hwif->lock);
+               return BLK_STS_DEV_RESOURCE;
+       }
+       spin_unlock_irq(&hwif->lock);
+
+       blk_mq_start_request(bd->rq);
+       return ide_issue_rq(drive, bd->rq, false);
+}
+
 static int drive_is_ready(ide_drive_t *drive)
 {
        ide_hwif_t *hwif = drive->hwif;
@@ -893,13 +899,8 @@ EXPORT_SYMBOL_GPL(ide_pad_transfer);
 
 void ide_insert_request_head(ide_drive_t *drive, struct request *rq)
 {
-       ide_hwif_t *hwif = drive->hwif;
-       unsigned long flags;
-
-       spin_lock_irqsave(&hwif->lock, flags);
+       drive->sense_rq_active = true;
        list_add_tail(&rq->queuelist, &drive->rq_list);
-       spin_unlock_irqrestore(&hwif->lock, flags);
-
        kblockd_schedule_work(&drive->rq_work);
 }
 EXPORT_SYMBOL_GPL(ide_insert_request_head);

diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
index 102aa3bc3e7fc11e672bd15051f4c4a94de6a669..8af7af6001eb36cd28bdfd840c206942e1fda5c0 100644 (file)
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@@ -54,7 +54,9 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
        scsi_req(rq)->cmd[0] = REQ_UNPARK_HEADS;
        scsi_req(rq)->cmd_len = 1;
        ide_req(rq)->type = ATA_PRIV_MISC;
+       spin_lock_irq(&hwif->lock);
        ide_insert_request_head(drive, rq);
+       spin_unlock_irq(&hwif->lock);
 
 out:
        return;

diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 63627be0811a740142c769bcc66da80f64cc101e..5aeaca24a28f35a9f11744deeab46f9dcb18745d 100644 (file)
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1159,18 +1159,27 @@ static void drive_rq_insert_work(struct work_struct *work)
        ide_drive_t *drive = container_of(work, ide_drive_t, rq_work);
        ide_hwif_t *hwif = drive->hwif;
        struct request *rq;
+       blk_status_t ret;
        LIST_HEAD(list);
 
-       spin_lock_irq(&hwif->lock);
-       if (!list_empty(&drive->rq_list))
-               list_splice_init(&drive->rq_list, &list);
-       spin_unlock_irq(&hwif->lock);
+       blk_mq_quiesce_queue(drive->queue);
 
-       while (!list_empty(&list)) {
-               rq = list_first_entry(&list, struct request, queuelist);
+       ret = BLK_STS_OK;
+       spin_lock_irq(&hwif->lock);
+       while (!list_empty(&drive->rq_list)) {
+               rq = list_first_entry(&drive->rq_list, struct request, queuelist);
                list_del_init(&rq->queuelist);
-               blk_execute_rq_nowait(drive->queue, rq->rq_disk, rq, true, NULL);
+
+               spin_unlock_irq(&hwif->lock);
+               ret = ide_issue_rq(drive, rq, true);
+               spin_lock_irq(&hwif->lock);
        }
+       spin_unlock_irq(&hwif->lock);
+
+       blk_mq_unquiesce_queue(drive->queue);
+
+       if (ret != BLK_STS_OK)
+               kblockd_schedule_work(&drive->rq_work);
 }
 
 static const u8 ide_hwif_to_major[] =

diff --git a/include/linux/ide.h b/include/linux/ide.h
index e7d29ae633cd09d2fb2d0ad6a0094bf9df1cc426..971cf76a78a081d7fc8d96cda096810476169155 100644 (file)
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -615,6 +615,7 @@ struct ide_drive_s {
 
        /* current sense rq and buffer */
        bool sense_rq_armed;
+       bool sense_rq_active;
        struct request *sense_rq;
        struct request_sense sense_data;
 
@@ -1219,6 +1220,7 @@ extern void ide_stall_queue(ide_drive_t *drive, unsigned long timeout);
 extern void ide_timer_expiry(struct timer_list *t);
 extern irqreturn_t ide_intr(int irq, void *dev_id);
 extern blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *);
+extern blk_status_t ide_issue_rq(ide_drive_t *, struct request *, bool);
 extern void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq);
 
 void ide_init_disk(struct gendisk *, ide_drive_t *);