99 lines
3.3 KiB
Plaintext
99 lines
3.3 KiB
Plaintext
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From: Hannes Reinecke <hare@suse.de>
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Subject: Kernel bug triggered in multipath
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References: bnc#486001
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Patch-mainline: not yet
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Starting multipath on a cciss device will cause a kernel
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warning to be triggered. Problem is that we're using the
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->queuedata field of the request_queue to derefence the
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scsi device; however, for other (non-SCSI) devices this
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points to a totally different structure.
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So we should rather be using accessors here which make
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sure we're only returning valid SCSI device structures.
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Signed-off-by: Hannes Reinecke <hare@suse.de>
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---
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drivers/scsi/device_handler/scsi_dh.c | 10 +++++-----
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drivers/scsi/scsi_lib.c | 11 +++++++++++
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include/scsi/scsi_device.h | 1 +
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3 files changed, 17 insertions(+), 5 deletions(-)
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--- a/drivers/scsi/device_handler/scsi_dh.c
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+++ b/drivers/scsi/device_handler/scsi_dh.c
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@@ -438,7 +438,7 @@ int scsi_dh_activate(struct request_queu
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struct scsi_device_handler *scsi_dh = NULL;
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spin_lock_irqsave(q->queue_lock, flags);
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- sdev = q->queuedata;
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+ sdev = scsi_device_from_queue(q);
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if (sdev && sdev->scsi_dh_data)
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scsi_dh = sdev->scsi_dh_data->scsi_dh;
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if (!scsi_dh || !get_device(&sdev->sdev_gendev))
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@@ -500,7 +500,7 @@ int scsi_dh_handler_exist(const char *na
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EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
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/*
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- * scsi_dh_handler_attach - Attach device handler
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+ * scsi_dh_attach - Attach device handler
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* @sdev - sdev the handler should be attached to
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* @name - name of the handler to attach
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*/
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@@ -516,7 +516,7 @@ int scsi_dh_attach(struct request_queue
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return -EINVAL;
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spin_lock_irqsave(q->queue_lock, flags);
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- sdev = q->queuedata;
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+ sdev = scsi_device_from_queue(q);
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if (!sdev || !get_device(&sdev->sdev_gendev))
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err = -ENODEV;
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spin_unlock_irqrestore(q->queue_lock, flags);
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@@ -530,7 +530,7 @@ int scsi_dh_attach(struct request_queue
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EXPORT_SYMBOL_GPL(scsi_dh_attach);
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/*
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- * scsi_dh_handler_detach - Detach device handler
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+ * scsi_dh_detach - Detach device handler
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* @sdev - sdev the handler should be detached from
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*
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* This function will detach the device handler only
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@@ -544,7 +544,7 @@ void scsi_dh_detach(struct request_queue
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struct scsi_device_handler *scsi_dh = NULL;
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spin_lock_irqsave(q->queue_lock, flags);
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- sdev = q->queuedata;
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+ sdev = scsi_device_from_queue(q);
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if (!sdev || !get_device(&sdev->sdev_gendev))
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sdev = NULL;
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spin_unlock_irqrestore(q->queue_lock, flags);
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--- a/drivers/scsi/scsi_lib.c
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+++ b/drivers/scsi/scsi_lib.c
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@@ -1595,6 +1595,17 @@ static void scsi_request_fn(struct reque
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spin_lock_irq(q->queue_lock);
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}
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+struct scsi_device *scsi_device_from_queue(struct request_queue *q)
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+{
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+ struct scsi_device *sdev = NULL;
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+
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+ if (q->request_fn == scsi_request_fn)
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+ sdev = q->queuedata;
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+
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+ return sdev;
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+}
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+EXPORT_SYMBOL_GPL(scsi_device_from_queue);
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+
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u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
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{
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struct device *host_dev;
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--- a/include/scsi/scsi_device.h
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+++ b/include/scsi/scsi_device.h
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@@ -297,6 +297,7 @@ extern void starget_for_each_device(stru
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extern void __starget_for_each_device(struct scsi_target *, void *,
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void (*fn)(struct scsi_device *,
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void *));
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+extern struct scsi_device *scsi_device_from_queue(struct request_queue *);
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/* only exposed to implement shost_for_each_device */
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extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *,
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