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path: root/drivers/scsi/scsi_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c54
1 files changed, 41 insertions, 13 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c9844043504e..1d83f29aee74 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -79,14 +79,15 @@ int scsi_init_sense_cache(struct Scsi_Host *shost)
if (shost->unchecked_isa_dma) {
scsi_sense_isadma_cache =
kmem_cache_create("scsi_sense_cache(DMA)",
- SCSI_SENSE_BUFFERSIZE, 0,
- SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL);
+ SCSI_SENSE_BUFFERSIZE, 0,
+ SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL);
if (!scsi_sense_isadma_cache)
ret = -ENOMEM;
} else {
scsi_sense_cache =
- kmem_cache_create("scsi_sense_cache",
- SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, NULL);
+ kmem_cache_create_usercopy("scsi_sense_cache",
+ SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN,
+ 0, SCSI_SENSE_BUFFERSIZE, NULL);
if (!scsi_sense_cache)
ret = -ENOMEM;
}
@@ -190,7 +191,19 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
*/
cmd->result = 0;
if (q->mq_ops) {
- scsi_mq_requeue_cmd(cmd);
+ /*
+ * Before a SCSI command is dispatched,
+ * get_device(&sdev->sdev_gendev) is called and the host,
+ * target and device busy counters are increased. Since
+ * requeuing a request causes these actions to be repeated and
+ * since scsi_device_unbusy() has already been called,
+ * put_device(&device->sdev_gendev) must still be called. Call
+ * put_device() after blk_mq_requeue_request() to avoid that
+ * removal of the SCSI device can start before requeueing has
+ * happened.
+ */
+ blk_mq_requeue_request(cmd->request, true);
+ put_device(&device->sdev_gendev);
return;
}
spin_lock_irqsave(q->queue_lock, flags);
@@ -857,6 +870,17 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
/* for passthrough error may be set */
error = BLK_STS_OK;
}
+ /*
+ * Another corner case: the SCSI status byte is non-zero but 'good'.
+ * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when
+ * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD
+ * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related
+ * intermediate statuses (both obsolete in SAM-4) as good.
+ */
+ if (status_byte(result) && scsi_status_is_good(result)) {
+ result = 0;
+ error = BLK_STS_OK;
+ }
/*
* special case: failed zero length commands always need to
@@ -1987,6 +2011,8 @@ static bool scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx)
out_put_device:
put_device(&sdev->sdev_gendev);
out:
+ if (atomic_read(&sdev->device_busy) == 0 && !scsi_device_blocked(sdev))
+ blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
return false;
}
@@ -2048,9 +2074,9 @@ out_put_budget:
case BLK_STS_OK:
break;
case BLK_STS_RESOURCE:
- if (atomic_read(&sdev->device_busy) == 0 &&
- !scsi_device_blocked(sdev))
- blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
+ if (atomic_read(&sdev->device_busy) ||
+ scsi_device_blocked(sdev))
+ ret = BLK_STS_DEV_RESOURCE;
break;
default:
/*
@@ -2168,11 +2194,13 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
q->limits.cluster = 0;
/*
- * set a reasonable default alignment on word boundaries: the
- * host and device may alter it using
- * blk_queue_update_dma_alignment() later.
+ * Set a reasonable default alignment: The larger of 32-byte (dword),
+ * which is a common minimum for HBAs, and the minimum DMA alignment,
+ * which is set by the platform.
+ *
+ * Devices that require a bigger alignment can increase it later.
*/
- blk_queue_dma_alignment(q, 0x03);
+ blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1);
}
EXPORT_SYMBOL_GPL(__scsi_init_queue);
@@ -2606,7 +2634,7 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
/* try to eat the UNIT_ATTENTION if there are enough retries */
do {
result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
- timeout, retries, NULL);
+ timeout, 1, NULL);
if (sdev->removable && scsi_sense_valid(sshdr) &&
sshdr->sense_key == UNIT_ATTENTION)
sdev->changed = 1;