Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1276864 > unrolled thread

[PATCH 3.2 39/52] scsi: Fix a bdi reregistration race

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 3.2 39/52] scsi: Fix a bdi reregistration race Ben Hutchings <ben@decadent.org.uk> - 2015-11-24 23:50 +0100
    Re: [PATCH 3.2 39/52] scsi: Fix a bdi reregistration race Ben Hutchings <ben@decadent.org.uk> - 2015-11-25 19:10 +0100

#1276864 — [PATCH 3.2 39/52] scsi: Fix a bdi reregistration race

3.2.74-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bart.vanassche@sandisk.com>

commit bf2cf3baa20b0a6cd2d08707ef05dc0e992a8aa0 upstream.

Unregister and reregister BDI devices in the proper order. This patch
avoids that the following kernel warning can get triggered:

WARNING: CPU: 7 PID: 203 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x68/0x80()
sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:32'
Workqueue: events_unbound async_run_entry_fn
Call Trace:
[<ffffffff814ff5a4>] dump_stack+0x4c/0x65
[<ffffffff810746ba>] warn_slowpath_common+0x8a/0xc0
[<ffffffff81074736>] warn_slowpath_fmt+0x46/0x50
[<ffffffff81237ca8>] sysfs_warn_dup+0x68/0x80
[<ffffffff81237d8e>] sysfs_create_dir_ns+0x7e/0x90
[<ffffffff81291f58>] kobject_add_internal+0xa8/0x320
[<ffffffff812923a0>] kobject_add+0x60/0xb0
[<ffffffff8138c937>] device_add+0x107/0x5e0
[<ffffffff8138d018>] device_create_groups_vargs+0xd8/0x100
[<ffffffff8138d05c>] device_create_vargs+0x1c/0x20
[<ffffffff8117f233>] bdi_register+0x63/0x2a0
[<ffffffff8117f497>] bdi_register_dev+0x27/0x30
[<ffffffff81281549>] add_disk+0x1a9/0x4e0
[<ffffffffa00c5739>] sd_probe_async+0x119/0x1d0 [sd_mod]
[<ffffffff8109a81a>] async_run_entry_fn+0x4a/0x140
[<ffffffff81091078>] process_one_work+0x1d8/0x7c0
[<ffffffff81091774>] worker_thread+0x114/0x460
[<ffffffff81097878>] kthread+0xf8/0x110
[<ffffffff8150801f>] ret_from_fork+0x3f/0x70

See also patch "block: destroy bdi before blockdev is unregistered"
(commit ID 6cd18e711dd8).

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 drivers/scsi/scsi_sysfs.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -955,9 +955,7 @@ void __scsi_remove_device(struct scsi_de
 		bsg_unregister_queue(sdev->request_queue);
 		device_unregister(&sdev->sdev_dev);
 		transport_remove_device(dev);
-		device_del(dev);
-	} else
-		put_device(&sdev->sdev_dev);
+	}
 
 	/*
 	 * Stop accepting new requests and wait until all queuecommand() and
@@ -968,6 +966,16 @@ void __scsi_remove_device(struct scsi_de
 	blk_cleanup_queue(sdev->request_queue);
 	cancel_work_sync(&sdev->requeue_work);
 
+	/*
+	 * Remove the device after blk_cleanup_queue() has been called such
+	 * a possible bdi_register() call with the same name occurs after
+	 * blk_cleanup_queue() has called bdi_destroy().
+	 */
+	if (sdev->is_visible)
+		device_del(dev);
+	else
+		put_device(&sdev->sdev_dev);
+
 	if (sdev->host->hostt->slave_destroy)
 		sdev->host->hostt->slave_destroy(sdev);
 	transport_destroy_device(dev);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1277668

[Multipart message — attachments visible in raw view] — view raw

On Tue, 2015-11-24 at 14:39 -0800, Bart Van Assche wrote:
> On 11/24/2015 02:35 PM, Ben Hutchings wrote:
> > 3.2.74-rc1 review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: Bart Van Assche <bart.vanassche@sandisk.com>
> > 
> > commit bf2cf3baa20b0a6cd2d08707ef05dc0e992a8aa0 upstream.
> 
> Hi Ben,
> 
> This patch fixes one bug but introduces another one ... So it's probably 
> better to drop this patch. See also the discussion in 
> http://www.spinics.net/lists/linux-scsi/msg90920.html.

Thanks, I've now dropped it.

Ben.

-- 
Ben Hutchings
This sentence contradicts itself - no actually it doesn't.

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web