From 522939d45c293388e6a360210905f9230298df16 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Mon, 10 Dec 2007 15:49:31 -0800 Subject: [PATCH] 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 Acked-by: David S. Miller Cc: James Bottomley Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/scsi/esp_scsi.c | 4 ++-- drivers/scsi/scsi.c | 31 +++++++++++++++++++++++++++++-- include/scsi/scsi_device.h | 3 +++ 3 files changed, 34 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c index 4ed3a5297066..bfdee5968892 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 192948822455..0fb1709ce5e3 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); @@ -914,6 +914,33 @@ 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 diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 66e9058357e0..6c2d80b36aa1 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 *,