Re: [-next] BUG_ON in scsi_target_destroy()

From: Johannes Thumshirn <jthumshirn@suse.de>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: "Ewan D. Milne" <emilne@redhat.com>,
	Hannes Reinecke <hare@suse.com>,
	James Bottomley <jejb@linux.vnet.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-next@vger.kernel.org,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Xiong Zhou <jencce.kernel@gmail.com>
Subject: Re: [-next] BUG_ON in scsi_target_destroy()
Date: Wed, 13 Apr 2016 10:41:50 +0200	[thread overview]
Message-ID: <2201725.I2to9GCRQJ@c203> (raw)
In-Reply-To: <20160411090146.GA537@swordfish>

Hi Sergey,  Xiong,

Can you try below patch?

On Montag, 11. April 2016 18:01:47 CEST Sergey Senozhatsky wrote:
> Hello,
> 
> commit 7b106f2de6938c31ce5e9c86bc70ad3904666b96
> Author: Johannes Thumshirn <jthumshirn@suse.de>
> Date:   Tue Apr 5 11:50:44 2016 +0200
> 
>     scsi: Add intermediate STARGET_REMOVE state to scsi_target_state
> 
> 
> BUG_ON()s (next-20160411) each time I remove a usb flash
> 
> [   49.561600]  [<ffffffffa0087f42>] scsi_target_destroy+0x5a/0xcb [scsi_mod]
> [   49.561607]  [<ffffffffa0089099>] scsi_target_reap+0x4a/0x4f [scsi_mod]
> [   49.561613]  [<ffffffffa008b453>] __scsi_remove_device+0xc3/0xd0 [scsi_mod]
> [   49.561619]  [<ffffffffa0089d7b>] scsi_forget_host+0x52/0x63 [scsi_mod]
> [   49.561623]  [<ffffffffa0080dbc>] scsi_remove_host+0x8c/0x102 [scsi_mod]
> [   49.561627]  [<ffffffffa015c447>] usb_stor_disconnect+0x6b/0xab [usb_storage]
> [   49.561634]  [<ffffffffa0013f73>] usb_unbind_interface+0x77/0x1ca [usbcore]
> [   49.561636]  [<ffffffff813ae064>] __device_release_driver+0x9d/0x121
> [   49.561638]  [<ffffffff813ae10b>] device_release_driver+0x23/0x30
> [   49.561639]  [<ffffffff813ad2d1>] bus_remove_device+0xfb/0x10e
> [   49.561641]  [<ffffffff813aac05>] device_del+0x164/0x1e6
> [   49.561648]  [<ffffffffa0011b09>] ? remove_intf_ep_devs+0x3b/0x48 [usbcore]
> [   49.561655]  [<ffffffffa001200e>] usb_disable_device+0x84/0x1a5 [usbcore]
> [   49.561661]  [<ffffffffa000ac7b>] usb_disconnect+0x94/0x19f [usbcore]
> [   49.561667]  [<ffffffffa000c2ab>] hub_event+0x5c1/0xdea [usbcore]
> [   49.561670]  [<ffffffff810530b1>] process_one_work+0x1dc/0x37f
> [   49.561672]  [<ffffffff81053dc5>] worker_thread+0x282/0x36d
> [   49.561673]  [<ffffffff81053b43>] ? rescuer_thread+0x2ae/0x2ae
> [   49.561675]  [<ffffffff810580a8>] kthread+0xd2/0xda
> [   49.561678]  [<ffffffff814bbf92>] ret_from_fork+0x22/0x40
> [   49.561679]  [<ffffffff81057fd6>] ? kthread_worker_fn+0x13e/0x13e
> 
> 	-ss
> --
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diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 0734927..0c00928 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1276,6 +1276,7 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
 void __scsi_remove_device(struct scsi_device *sdev)
 {
 	struct device *dev = &sdev->sdev_gendev;
+	struct scsi_target *starget;
 
 	/*
 	 * This cleanup path is not reentrant and while it is impossible
@@ -1315,7 +1316,9 @@ void __scsi_remove_device(struct scsi_device *sdev)
 	 * remoed sysfs visibility from the device, so make the target
 	 * invisible if this was the last device underneath it.
 	 */
-	scsi_target_reap(scsi_target(sdev));
+	starget = scsi_target(sdev);
+	starget->state = STARGET_REMOVE;
+	scsi_target_reap(starget);
 
 	put_device(dev);
 }



-- 
Johannes Thumshirn                                                                                Storage
jthumshirn@suse.de                                                             +49 911 74053 689
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