On 26/11/14 15:33, Tim Small wrote: > I decided to exercise the eject code path a bit more by triggering > simultaneous eject commands on all 11 optical drives in my test box, > followed by simultaneous close-tray commands, repeatedly. ... > > Unfortunately running these tests did eventually make all further > attempts to open /dev/sr* block on my test box. > > I've stared at the code for a while, but not making any headway > currently, except that a blocking blk_execute_rq (called by > test_unit_ready) is then causing all over cdrom open/close calls to > block (because sr_mutex is held by sr_block_open(), and in turn calls > check_disk_change... scsi_test_unit_ready). > > How do I work out why blk_execute_rq is blocking? > > # ps -l 3779 2383 3780 > F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD > 1 D 0 2383 2 0 80 0 - 0 blk_ex ? 0:00 [kworker/1:2] > 0 D 0 3779 1034 0 80 0 - 1057 blk_ex pts/0 0:00 eject -t /dev/sr7 > 0 D 0 3780 1034 0 80 0 - 0 sr_blo pts/0 0:00 [eject] > > > > /proc/3779/stack-[<ffffffff812e47cb>] blk_execute_rq+0x16b/0x210 > /proc/3779/stack-[<ffffffffa0291cb1>] scsi_execute+0x141/0x1f0 [scsi_mod] > /proc/3779/stack-[<ffffffffa0293e1e>] scsi_execute_req_flags+0x8e/0x100 [scsi_mod] > /proc/2383/stack-[<ffffffff812e47cb>] blk_execute_rq+0x16b/0x210 > /proc/2383/stack-[<ffffffffa0291cb1>] scsi_execute+0x141/0x1f0 [scsi_mod] > /proc/2383/stack-[<ffffffffa0293e1e>] scsi_execute_req_flags+0x8e/0x100 [scsi_mod] > /proc/2383/stack-[<ffffffffa02944f3>] scsi_test_unit_ready+0x83/0x130 [scsi_mod] An extra data point, the drive is showing busy: # cat /sys/block/sr7/device/device_busy 1 I was wondering if this might be an unrelated bug in the drive or host adaptor driver? This device is attached to an old PCI card using pata_pdc2027x, and has an old firmware version, so I'm going to try and change both of those things and try again. Tim. -- 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
