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authorMaciej W. Rozycki <macro@linux-mips.org>2007-12-10 18:49:31 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-12-10 22:43:55 -0500
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 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)
2026 tp->flags |= ESP_TGT_CHECK_NEGO; 2026 tp->flags |= ESP_TGT_CHECK_NEGO;
2027 2027
2028 if (tp->starget) 2028 if (tp->starget)
2029 starget_for_each_device(tp->starget, NULL, 2029 __starget_for_each_device(tp->starget, NULL,
2030 esp_clear_hold); 2030 esp_clear_hold);
2031 } 2031 }
2032 esp->flags &= ~ESP_FLAG_RESETTING; 2032 esp->flags &= ~ESP_FLAG_RESETTING;
2033} 2033}
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);
896 * starget_for_each_device - helper to walk all devices of a target 896 * starget_for_each_device - helper to walk all devices of a target
897 * @starget: target whose devices we want to iterate over. 897 * @starget: target whose devices we want to iterate over.
898 * 898 *
899 * This traverses over each devices of @shost. The devices have 899 * This traverses over each device of @starget. The devices have
900 * a reference that must be released by scsi_host_put when breaking 900 * a reference that must be released by scsi_host_put when breaking
901 * out of the loop. 901 * out of the loop.
902 */ 902 */
903void starget_for_each_device(struct scsi_target *starget, void * data, 903void starget_for_each_device(struct scsi_target *starget, void *data,
904 void (*fn)(struct scsi_device *, void *)) 904 void (*fn)(struct scsi_device *, void *))
905{ 905{
906 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 906 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,
915EXPORT_SYMBOL(starget_for_each_device); 915EXPORT_SYMBOL(starget_for_each_device);
916 916
917/** 917/**
918 * __starget_for_each_device - helper to walk all devices of a target
919 * (UNLOCKED)
920 * @starget: target whose devices we want to iterate over.
921 *
922 * This traverses over each device of @starget. It does _not_
923 * take a reference on the scsi_device, so the whole loop must be
924 * protected by shost->host_lock.
925 *
926 * Note: The only reason why drivers would want to use this is because
927 * they need to access the device list in irq context. Otherwise you
928 * really want to use starget_for_each_device instead.
929 **/
930void __starget_for_each_device(struct scsi_target *starget, void *data,
931 void (*fn)(struct scsi_device *, void *))
932{
933 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
934 struct scsi_device *sdev;
935
936 __shost_for_each_device(sdev, shost) {
937 if ((sdev->channel == starget->channel) &&
938 (sdev->id == starget->id))
939 fn(sdev, data);
940 }
941}
942EXPORT_SYMBOL(__starget_for_each_device);
943
944/**
918 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) 945 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
919 * @starget: SCSI target pointer 946 * @starget: SCSI target pointer
920 * @lun: SCSI Logical Unit Number 947 * @lun: SCSI Logical Unit Number
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 *,
242 uint); 242 uint);
243extern void starget_for_each_device(struct scsi_target *, void *, 243extern void starget_for_each_device(struct scsi_target *, void *,
244 void (*fn)(struct scsi_device *, void *)); 244 void (*fn)(struct scsi_device *, void *));
245extern void __starget_for_each_device(struct scsi_target *, void *,
246 void (*fn)(struct scsi_device *,
247 void *));
245 248
246/* only exposed to implement shost_for_each_device */ 249/* only exposed to implement shost_for_each_device */
247extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *, 250extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *,