I made a microsd flash with 2 partitions, sdb1 is data partition, and sdb2 is a sentinel partition, 1 block in size. I attached the usb-microsd reader with that card in it and by mistake tried to mount the sentinel partition, I ran: mount /dev/sdb2 /mnt/flash/ mount got stuck, I was not able to kill or strace it, I pulled the usb reader from the port, mount was still stuck, here's the dmesg log: [65464.536212] usb 4-1.2: new high-speed USB device number 3 using ehci_hcd [65464.700933] usbcore: registered new interface driver uas [65464.703478] Initializing USB Mass Storage driver... [65464.703762] scsi8 : usb-storage 4-1.2:1.0 [65464.703852] usbcore: registered new interface driver usb-storage [65464.703854] USB Mass Storage support registered. [65465.706479] scsi 8:0:0:0: Direct-Access Generic- Card Reader 1.00 PQ: 0 ANSI: 0 CCS [65466.389664] sd 8:0:0:0: [sdb] 3862528 512-byte logical blocks: (1.97 GB/1.84 GiB) [65466.390493] sd 8:0:0:0: [sdb] Write Protect is off [65466.390497] sd 8:0:0:0: [sdb] Mode Sense: 03 00 00 00 [65466.391263] sd 8:0:0:0: [sdb] No Caching mode page present [65466.391267] sd 8:0:0:0: [sdb] Assuming drive cache: write through [65466.394723] sd 8:0:0:0: [sdb] No Caching mode page present [65466.394727] sd 8:0:0:0: [sdb] Assuming drive cache: write through [65466.397500] sdb: sdb1 sdb2 [65466.400468] sd 8:0:0:0: [sdb] No Caching mode page present [65466.400471] sd 8:0:0:0: [sdb] Assuming drive cache: write through [65466.400474] sd 8:0:0:0: [sdb] Attached SCSI removable disk [66159.793752] usb 4-1.2: USB disconnect, device number 3 [66291.567080] INFO: task khubd:90 blocked for more than 120 seconds. [66291.567083] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [66291.567086] khubd D 0000000000000001 0 90 2 0x00000000 [66291.567090] ffff880230313948 0000000000000046 ffff88023233e000 ffff880230313fd8 [66291.567095] ffff880230313fd8 ffff880230313fd8 ffff880194f8b000 ffff88023233e000 [66291.567099] ffffffff81244c85 ffff880194f8b048 0000000000000046 ffff8802303138c0 [66291.567104] Call Trace: [66291.567112] [<ffffffff81244c85>] ? number.isra.2+0x315/0x350 [66291.567117] [<ffffffff811b091b>] ? ep_poll_callback+0xeb/0x120 [66291.567121] [<ffffffff81244cfe>] ? string.isra.4+0x3e/0xd0 [66291.567125] [<ffffffff8145e50f>] schedule+0x3f/0x60 [66291.567129] [<ffffffff8145ef35>] rwsem_down_failed_common+0xc5/0x160 [66291.567133] [<ffffffff81185f49>] ? find_inode+0xa9/0xb0 [66291.567136] [<ffffffff8145f005>] rwsem_down_read_failed+0x15/0x17 [66291.567139] [<ffffffff81248434>] call_rwsem_down_read_failed+0x14/0x30 [66291.567143] [<ffffffff8145d3d7>] ? down_read+0x17/0x20 [66291.567146] [<ffffffff8116ebdf>] get_super+0x9f/0xe0 [66291.567149] [<ffffffff811a4d9d>] fsync_bdev+0x1d/0x60 [66291.567152] [<ffffffff81227a2d>] invalidate_partition+0x2d/0x60 [66291.567155] [<ffffffff81228920>] del_gendisk+0x90/0x250 [66291.567170] [<ffffffffa01004ed>] sd_remove+0x6d/0xb0 [sd_mod] [66291.567177] [<ffffffff8130ae0c>] __device_release_driver+0x7c/0xe0 [66291.567181] [<ffffffff8130ae9c>] device_release_driver+0x2c/0x40 [66291.567185] [<ffffffff8130a931>] bus_remove_device+0xe1/0x120 [66291.567188] [<ffffffff8130848a>] device_del+0x12a/0x1b0 [66291.567195] [<ffffffffa01211f5>] __scsi_remove_device+0xc5/0xd0 [scsi_mod] [66291.567202] [<ffffffffa011fb54>] scsi_forget_host+0x64/0x70 [scsi_mod] [66291.567209] [<ffffffffa01165cf>] scsi_remove_host+0x6f/0x120 [scsi_mod] [66291.567213] [<ffffffffa04d26e3>] usb_stor_disconnect+0x63/0xd0 [usb_storage] [66291.567221] [<ffffffffa0154240>] usb_unbind_interface+0x50/0x180 [usbcore] [66291.567226] [<ffffffff8130ae0c>] __device_release_driver+0x7c/0xe0 [66291.567229] [<ffffffff8130ae9c>] device_release_driver+0x2c/0x40 [66291.567233] [<ffffffff8130a931>] bus_remove_device+0xe1/0x120 [66291.567236] [<ffffffff8130848a>] device_del+0x12a/0x1b0 [66291.567243] [<ffffffffa0151fef>] usb_disable_device+0xaf/0x1f0 [usbcore] [66291.567250] [<ffffffffa014a427>] usb_disconnect+0x87/0x120 [usbcore] [66291.567256] [<ffffffffa014be1b>] hub_thread+0x54b/0x12a0 [usbcore] [66291.567261] [<ffffffff81072540>] ? abort_exclusive_wait+0xb0/0xb0 [66291.567268] [<ffffffffa014b8d0>] ? usb_remote_wakeup+0x40/0x40 [usbcore] [66291.567272] [<ffffffff81071bc3>] kthread+0x93/0xa0 [66291.567275] [<ffffffff81461664>] kernel_thread_helper+0x4/0x10 [66291.567279] [<ffffffff81071b30>] ? kthread_freezable_should_stop+0x70/0x70 [66291.567282] [<ffffffff81461660>] ? gs_change+0x13/0x13 subsequent to this, another khubd and systemd-udevd are reported blocked in terms. kernel 3.3.8-1-ARCH #1 x86_64 I think I will have to reboot to get usb running again Tell if there's something I can do to narrow down this issue as I see it is rather vague as it is now. Thanks, Dima Tisnek -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
