James and Jens: I got a WARNING when unbinding the sd driver from a USB flash drive and then binding it back again. Here's where the flash drive gets probed initially: [ 143.300886] usb-storage 4-8:1.0: usb_probe_interface [ 143.300911] usb-storage 4-8:1.0: usb_probe_interface - got id [ 143.300930] usb-storage 4-8:1.0: USB Mass Storage device detected [ 143.318239] scsi host0: usb-storage 4-8:1.0 [ 143.359979] scsi 0:0:0:0: Direct-Access Ut165 USB2FlashStorage 0.00 PQ: 0 ANSI: 2 [ 143.376366] usbcore: registered new interface driver usb-storage [ 143.468464] sd 0:0:0:0: [sda] 7892040 512-byte logical blocks: (4.04 GB/3.76 GiB) [ 143.481725] sd 0:0:0:0: [sda] Write Protect is off [ 143.485712] sd 0:0:0:0: [sda] Mode Sense: 00 00 00 00 [ 143.487064] sd 0:0:0:0: [sda] Asking for cache data failed [ 143.498428] sd 0:0:0:0: [sda] Assuming drive cache: write through [ 143.656797] sda: sda1 [ 143.676922] sd 0:0:0:0: [sda] Attached SCSI removable disk Then I did echo 0:0:0:0 >/sys/bus/scsi/drivers/sd_mod/unbind followed by echo 0:0:0:0 >/sys/bus/scsi/drivers/sd_mod/bind which resulted in: [ 165.079557] sd 0:0:0:0: [sda] 7892040 512-byte logical blocks: (4.04 GB/3.76 GiB) [ 165.093510] sd 0:0:0:0: [sda] Write Protect is off [ 165.104388] sd 0:0:0:0: [sda] Mode Sense: 00 00 00 00 [ 165.105632] sd 0:0:0:0: [sda] Asking for cache data failed [ 165.115136] sd 0:0:0:0: [sda] Assuming drive cache: write through [ 165.142950] sda: sda1 [ 165.156480] ------------[ cut here ]------------ [ 165.159912] WARNING: CPU: 0 PID: 29 at block/blk-core.c:473 blk_queue_bypass_end+0x4d/0x62() [ 165.160030] Modules linked in: sd_mod usb_storage scsi_mod hid_generic usbhid hid pcspkr evdev i915 cfbfillrect cfbimgblt i2c_algo_bit cfbcopyarea video fbcon backlight bitblit softcursor font ehci_pci drm_kms_helper uhci_hcd ehci_hcd ohci_pci ohci_hcd drm i2ccore usbcore e100 mii usb_common fb fbdev fan processor button thermal_sys [ 165.160030] CPU: 0 PID: 29 Comm: kworker/u4:1 Not tainted 3.17.0-rc3AS-dirty #12 [ 165.160030] Hardware name: Hewlett-Packard HP dx2000 MT (EE004AA)/08FCh, BIOS 1.17 11/24/2005 [ 165.160030] Workqueue: events_unbound async_run_entry_fn [ 165.160030] c105d2ef 00000000 ea569e10 c12771c0 00000000 ea569e28 c102c5fb c114907d [ 165.160030] ecc18000 ea619c20 ecc18000 ea569e38 c102c676 00000009 00000000 ea569e44 [ 165.160030] c114907d ea619c20 ea569e5c c114b97d ea569e5c ea619c20 ed74e400 ea619c2c [ 165.160030] Call Trace: [ 165.160030] [<c105d2ef>] ? console_unlock+0x37e/0x3ab [ 165.160030] [<c12771c0>] dump_stack+0x49/0x73 [ 165.160030] [<c102c5fb>] warn_slowpath_common+0x5c/0x73 [ 165.160030] [<c114907d>] ? blk_queue_bypass_end+0x4d/0x62 [ 165.160030] [<c102c676>] warn_slowpath_null+0xf/0x13 [ 165.160030] [<c114907d>] blk_queue_bypass_end+0x4d/0x62 [ 165.160030] [<c114b97d>] blk_register_queue+0x8f/0xc4 [ 165.160030] [<c11548a6>] add_disk+0x2bc/0x3a8 [ 165.160030] [<efff40a5>] sd_probe_async+0xf5/0x17b [sd_mod] [ 165.160030] [<c103fc08>] async_run_entry_fn+0x59/0xf9 [ 165.160030] [<c103ab22>] process_one_work+0x187/0x2ac [ 165.160030] [<c103aac4>] ? process_one_work+0x129/0x2ac [ 165.160030] [<c103ae19>] worker_thread+0x1b1/0x26b [ 165.160030] [<c103ac68>] ? process_scheduled_works+0x21/0x21 [ 165.160030] [<c103e4ee>] kthread+0x82/0x87 [ 165.160030] [<c127b074>] ? _raw_spin_unlock_irq+0x22/0x3f [ 165.160030] [<c1160000>] ? radix_tree_tag_set+0x3f/0xa5 [ 165.160030] [<c127b781>] ret_from_kernel_thread+0x21/0x30 [ 165.160030] [<c103e46c>] ? __kthread_parkme+0x50/0x50 [ 165.160030] ---[ end trace 31df765b6ea80892 ]--- [ 165.308986] sd 0:0:0:0: [sda] Attached SCSI removable disk I don't know what's going on here, but it looks like something doesn't get cleaned up properly during the unbind operation. This was in vanilla 3.17-rc3. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
