| Message ID | 1448921420-12035-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
On 11/30/2015 02:10 PM, Kamal Mostafa wrote: > This is a note to let you know that I have just added a patch titled > > scsi: Fix a bdi reregistration race > > to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree > which can be found at: > > http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue > > This patch is scheduled to be released in version 3.19.8-ckt11. > > If you, or anyone else, feels it should not be added to this tree, please > reply to this email. Hello Kamal, This patch fixes a race but introduces a new bug. So it's probably better to drop this patch. More information is available in the e-mail thread that is available at http://thread.gmane.org/gmane.linux.scsi/107519. Thanks, Bart.
On Mon, 2015-11-30 at 14:14 -0800, Bart Van Assche wrote: > On 11/30/2015 02:10 PM, Kamal Mostafa wrote: > > This is a note to let you know that I have just added a patch titled > > > > scsi: Fix a bdi reregistration race > > > > to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree > > which can be found at: > > > > http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue > > > > This patch is scheduled to be released in version 3.19.8-ckt11. > > > > If you, or anyone else, feels it should not be added to this tree, please > > reply to this email. > > Hello Kamal, > > This patch fixes a race but introduces a new bug. So it's probably > better to drop this patch. More information is available in the e-mail > thread that is available at http://thread.gmane.org/gmane.linux.scsi/107519. > > Thanks, > > Bart. > Got it -- dropping this patch from 3.19-stable. Thanks very much for the heads-up, Bart. -Kamal
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index e71eb8e..f582cc1 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1074,9 +1074,7 @@ void __scsi_remove_device(struct scsi_device *sdev) 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 @@ -1087,6 +1085,16 @@ void __scsi_remove_device(struct scsi_device *sdev) 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);
This is a note to let you know that I have just added a patch titled scsi: Fix a bdi reregistration race to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt11. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 72fb25f976fda3e1e0702a99413739c15601d39b Mon Sep 17 00:00:00 2001 From: Bart Van Assche <bart.vanassche@sandisk.com> Date: Fri, 18 Sep 2015 17:23:42 -0700 Subject: scsi: Fix a bdi reregistration race 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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/scsi/scsi_sysfs.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) -- 1.9.1