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authorMaciej W. Rozycki <macro@linux-mips.org>2007-12-10 15:49:31 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-12-10 19:43:55 -0800
commit522939d45c293388e6a360210905f9230298df16 (patch)
tree38c37c6688a5095ab49c8fd42425e2bf3fb61ae9
parent794e64d5e9c7f088378e093a48eb36a30091d82d (diff)
esp_scsi: fix reset cleanup spinlock recursion
The esp_reset_cleanup() function is called with the host lock held and invokes starget_for_each_device() which wants to take it too. Here is a fix along the lines of shost_for_each_device()/__shost_for_each_device() adding a __starget_for_each_device() counterpart which assumes the lock has already been taken. Eventually, I think the driver should get modified so that more work is done as a softirq rather than in the interrupt context, but for now it fixes a bug that causes the spinlock debugger to fire. While at it, it fixes a small number of cosmetic problems with starget_for_each_device() too. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/scsi/esp_scsi.c4
-rw-r--r--drivers/scsi/scsi.c31
-rw-r--r--include/scsi/scsi_device.h3
3 files changed, 34 insertions, 4 deletions
diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index 4ed3a529706..bfdee596889 100644
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -2026,8 +2026,8 @@ static void esp_reset_cleanup(struct esp *esp)
tp->flags |= ESP_TGT_CHECK_NEGO;
if (tp->starget)
- starget_for_each_device(tp->starget, NULL,
- esp_clear_hold);
+ __starget_for_each_device(tp->starget, NULL,
+ esp_clear_hold);
}
esp->flags &= ~ESP_FLAG_RESETTING;
}
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 19294882245..0fb1709ce5e 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -896,11 +896,11 @@ EXPORT_SYMBOL(__scsi_iterate_devices);
* starget_for_each_device - helper to walk all devices of a target
* @starget: target whose devices we want to iterate over.
*
- * This traverses over each devices of @shost. The devices have
+ * This traverses over each device of @starget. The devices have
* a reference that must be released by scsi_host_put when breaking
* out of the loop.
*/
-void starget_for_each_device(struct scsi_target *starget, void * data,
+void starget_for_each_device(struct scsi_target *starget, void *data,
void (*fn)(struct scsi_device *, void *))
{
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
@@ -915,6 +915,33 @@ void starget_for_each_device(struct scsi_target *starget, void * data,
EXPORT_SYMBOL(starget_for_each_device);
/**
+ * __starget_for_each_device - helper to walk all devices of a target
+ * (UNLOCKED)
+ * @starget: target whose devices we want to iterate over.
+ *
+ * This traverses over each device of @starget. It does _not_
+ * take a reference on the scsi_device, so the whole loop must be
+ * protected by shost->host_lock.
+ *
+ * Note: The only reason why drivers would want to use this is because
+ * they need to access the device list in irq context. Otherwise you
+ * really want to use starget_for_each_device instead.
+ **/
+void __starget_for_each_device(struct scsi_target *starget, void *data,
+ void (*fn)(struct scsi_device *, void *))
+{
+ struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
+ struct scsi_device *sdev;
+
+ __shost_for_each_device(sdev, shost) {
+ if ((sdev->channel == starget->channel) &&
+ (sdev->id == starget->id))
+ fn(sdev, data);
+ }
+}
+EXPORT_SYMBOL(__starget_for_each_device);
+
+/**
* __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
* @starget: SCSI target pointer
* @lun: SCSI Logical Unit Number
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 66e9058357e..6c2d80b36aa 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -242,6 +242,9 @@ extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *,
uint);
extern void starget_for_each_device(struct scsi_target *, void *,
void (*fn)(struct scsi_device *, void *));
+extern void __starget_for_each_device(struct scsi_target *, void *,
+ void (*fn)(struct scsi_device *,
+ void *));
/* only exposed to implement shost_for_each_device */
extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *,