Yes it does when there is IO failure But. But my question was when disk fail silently with out IO as show below. The md sysfs interface /sys/block/mdY/md/dev-sdX/state is written with faulty when sd corresponding disk is deleted with.. echo 1 > /sys/block/sdc/device/delete kernel: [21853.981735] sd 2:0:0:0: [sdc] Synchronizing SCSI cache kernel: [21854.049967] md: md0 still in use. kernel: [21854.051201] md/raid1:md0: Disk failure on sdc, disabling device. kernel: [21854.051201] md/raid1:md0: Operation continuing on 1 devices. kernel: [21854.308355] sd 2:0:0:0: [sdc] Stopping disk kernel: [21854.415122] ata3.00: disabled kernel: [21854.467540] md: unbind<sdc> kernel: [21854.467544] md: export_rdev(sdc) earlier stack dump which shows the sysfs write interface there has to be code monitoring block disk state, and propagating that state to the md ? Thx. On Fri, Apr 18, 2014 at 2:13 PM, NeilBrown <neilb@xxxxxxx> wrote: > On Fri, 18 Apr 2014 13:38:58 +0800 Sonu a <p10sonu@xxxxxxxxx> wrote: > >> when disk is removed with out mdadm as I see from the stack below the >> communication reaching the md driver. >> >> dump_stack+0x49/0x5e >> md_error+0x50/0x110 [md_mod] >> state_store+0x43/0x300 [md_mod] >> rdev_attr_store+0xad/0xd0 [md_mod] >> ? sysfs_write_file+0x62/0x1c0 >> sysfs_write_file+0x138/0x1c0 >> vfs_write+0xc0/0x1e0 >> SyS_write+0x5a/0xa0 >> ? __audit_syscall_exit+0x246/0x2f0 >> system_call_fastpath+0x16/0x1b >> >> could someone point me to the code which is monitoring scsi disks >> status and thus calling md driver sysfs interface accordingly ? > > I think you ask asking how md_error gets called when a SCSI device fails, > having already discovered how it is called when you explicitly write to a > sysfs file. > > Nothing monitors the scsi disks. md only discovers failure if it sends a > request to a disk, and the request signals an error. If you search for > 'bi_end_io', functions assigned to this field are called when a request > finishes. Those functions might call md_error if the request failed, or they > might schedule some other handling first to try to correct the error. > > NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
