Avoid that the sd driver registers a BDI device with a name that is still in use. This patch avoids that the following warning is triggered sporadically:
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 Signed-off-by: Bart Van Assche <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Hannes Reinecke <[email protected]> Cc: Joe Lawrence <[email protected]> Cc: <[email protected]> --- Changes compared to v4: - Renamed the device filter function. - Added test to skip sg child device. Changes between v3 and v4: - Added (dev->class != &sdev_class) test to device filter function. Changes between v2 and v3: - Switched from separating BDI unregistration and deletion to increasing the sd device reference count. Changes between v1 and v2: - Changed the approach from swapping the device_del() and blk_cleanup_queue() calls to separating BDI unregistration and deletion. drivers/scsi/scsi_sysfs.c | 45 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 0734927..64cebf5 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1273,9 +1273,41 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev) return error; } +/** + * scsi_filter_ulpdev - Look up the device created by the ULP SCSI driver + * @dev: A sdev_gendev device + * @data: A struct device pointer + * + * sdev_gendev devices have multiple children: the device(s) that has been + * created by the SCSI ULP driver (e.g. sd), the sdev_dev device and the sg + * device. The sd driver creates one device instance itself and zero or more + * device instances by creating genhd instances. These last devices represent + * partitions. Select the device that has been created by the ULP SCSI driver + * by returning the first device that is not the sdev_dev device nor the sg + * device. + */ +static int scsi_filter_ulpdev(struct device *dev, void *data) +{ + struct device **childp = data; + + if (!*childp && dev->class != &sdev_class && + strncmp(dev_name(dev), "sg", 2) != 0) + *childp = dev; + return 0; +} + +/* Caller must call put_device() if this function does not return NULL. */ +static struct device *scsi_get_ulpdev(struct device *dev) +{ + struct device *child = NULL; + + device_for_each_child(dev, &child, scsi_filter_ulpdev); + return get_device(child); +} + void __scsi_remove_device(struct scsi_device *sdev) { - struct device *dev = &sdev->sdev_gendev; + struct device *dev = &sdev->sdev_gendev, *sdp = NULL; /* * This cleanup path is not reentrant and while it is impossible @@ -1290,6 +1322,7 @@ void __scsi_remove_device(struct scsi_device *sdev) return; bsg_unregister_queue(sdev->request_queue); + sdp = scsi_get_ulpdev(dev); device_unregister(&sdev->sdev_dev); transport_remove_device(dev); scsi_dh_remove_device(sdev); @@ -1306,6 +1339,16 @@ void __scsi_remove_device(struct scsi_device *sdev) blk_cleanup_queue(sdev->request_queue); cancel_work_sync(&sdev->requeue_work); + /* + * blk_cleanup_queue() unregisters the BDI device. The name of the + * BDI device is derived from the dev_t of the /dev/sd<n> device. + * Keep a reference to the /dev/sd<n> device until the BDI device + * has been unregistered to avoid that a BDI device with the same + * name gets registered before blk_cleanup_queue() has finished. + */ + if (sdp) + put_device(sdp); + if (sdev->host->hostt->slave_destroy) sdev->host->hostt->slave_destroy(sdev); transport_destroy_device(dev); -- 2.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
