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    Subject[patch 35/60] esp_scsi: fix reset cleanup spinlock recursion

    2.6.23-stable review patch. If anyone has any objections, please let us
    know.

    ------------------
    From: "Maciej W. Rozycki" <macro@linux-mips.org>

    patch 522939d45c293388e6a360210905f9230298df16 in mainline.

    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>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    drivers/scsi/esp_scsi.c | 4 ++--
    drivers/scsi/scsi.c | 31 +++++++++++++++++++++++++++++--
    include/scsi/scsi_device.h | 3 +++
    3 files changed, 34 insertions(+), 4 deletions(-)

    --- a/drivers/scsi/esp_scsi.c
    +++ b/drivers/scsi/esp_scsi.c
    @@ -2026,8 +2026,8 @@ static void esp_reset_cleanup(struct 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;
    }
    --- a/drivers/scsi/scsi.c
    +++ b/drivers/scsi/scsi.c
    @@ -886,11 +886,11 @@ 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);
    @@ -905,6 +905,33 @@ void starget_for_each_device(struct scsi
    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
    --- a/include/scsi/scsi_device.h
    +++ b/include/scsi/scsi_device.h
    @@ -222,6 +222,9 @@ extern struct scsi_device *__scsi_device
    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 *,
    --


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