On Thu, Jan 14, 2010 at 01:24:59PM -0500, Douglas Gilbert wrote: > scameron@xxxxxxxxxxxxxxxxxx wrote: > >I'm seeing a problem which I think is a problem in the SCSI mid layer. > > > >Check this out: > > > >I can rmmod and insmod hpsa (a modified version from > >what's currently in the mainline tree, but I don't think > >that matters.) > > > >I have one logical drive present > > > >[root@slicer ~]# rmmod hpsa > >[root@slicer ~]# insmod /usr/src/linux-2.6.27.42/drivers/scsi/hpsa.ko > >[root@slicer ~]# cat /proc/scsi/scsi > >Attached devices: > >Host: scsi1 Channel: 00 Id: 00 Lun: 00 > > Vendor: HP Model: 1210m Rev: 0150 > > Type: RAID ANSI SCSI revision: 05 > >Host: scsi1 Channel: 00 Id: 00 Lun: 01 > > Vendor: HP Model: 1210m VOLUME Rev: 0150 > > Type: Direct-Access ANSI SCSI revision: 05 > >[root@slicer ~]# rmmod hpsa > >[root@slicer ~]# insmod /usr/src/linux-2.6.27.42/drivers/scsi/hpsa.ko > >[root@slicer ~]# cat /proc/scsi/scsi > >Attached devices: > >Host: scsi2 Channel: 00 Id: 00 Lun: 00 > > Vendor: HP Model: 1210m Rev: 0150 > > Type: RAID ANSI SCSI revision: 05 > >Host: scsi2 Channel: 00 Id: 00 Lun: 01 > > Vendor: HP Model: 1210m VOLUME Rev: 0150 > > Type: Direct-Access ANSI SCSI revision: 05 > >[root@slicer ~]# lsscsi -g > >[2:0:0:0] storage HP 1210m 0150 - /dev/sg0 > >[2:0:0:1] disk HP 1210m VOLUME 0150 /dev/sda /dev/sg1 > > > >So far, so good. > > > >Now, watch this. Remove the device while something has it open: > > > >[root@slicer ~]# sleep 10 < /dev/sg1 & ( sleep 1 && echo scsi > >remove-single-device 2 0 0 1 > /proc/scsi/scsi ) > >[1] 6077 > >[root@slicer ~]# > >[1]+ Done sleep 10 < /dev/sg1 > >[root@slicer ~]# lsof /dev/sg1 > >lsof: status error on /dev/sg1: No such file or directory > >lsof 4.78 > > latest revision: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/ > > latest FAQ: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/FAQ > > latest man page: ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/lsof_man > > usage: [-?abhlnNoOPRstUvVX] [+|-c c] [+|-d s] [+D D] [+|-f] > > [-F [f]] [-g [s]] [-i [i]] [+|-L [l]] [+m [m]] [+|-M] [-o [o]] > > [-p s] [+|-r [t]] [-S [t]] [-T [t]] [-u s] [+|-w] [-x [fl]] [-Z [Z]] [--] > > [names] > >Use the ``-h'' option to get more help information. > >[root@slicer ~]# rmmod hpsa > >ERROR: Module hpsa is in use > >[root@slicer ~]# > > > >Hmm, that's not cool. > > Steve, > That 'sleep 10 < /dev/sg1' worries me. The purpose of a > read() on a sg device is to fetch the response of a SCSI > command sent by a preceding write(). So with nothing to > read and a blocking sg device file descriptor the read() > probably hangs. IMO the valid use of the sg driver should > not have a read() hanging for a SCSI command that was > never sent. While that is happening you remove the > device. > > That may be a valid torture test for the sg driver but > isn't something that should be encouraged from the > user space. > > On a Ubuntu kernel 2.6.31-17-generic using a virtual > device owned by the scsi_debug driver and the same > torture test, I don't have a problem with 'rmmod scsi_debug' > > IMO the usb-storage driver is not a good yardstick. I tried it with mptsas with the same results: mptlinuxtest:~ # cat /proc/scsi/scsi mptlinuxtest:~ # modprobe mptsas mptlinuxtest:~ # cat /proc/scsi/scsi Attached devices: Host: scsi2 Channel: 00 Id: 00 Lun: 00 Vendor: HP Model: DG072A9BB7 Rev: HPD0 Type: Direct-Access ANSI SCSI revision: 05 Host: scsi2 Channel: 00 Id: 01 Lun: 00 Vendor: HP Model: DG072A8B54 Rev: HPD4 Type: Direct-Access ANSI SCSI revision: 05 Host: scsi2 Channel: 01 Id: 03 Lun: 00 Vendor: LSILOGIC Model: Logical Volume Rev: 3000 Type: Direct-Access ANSI SCSI revision: 02 mptlinuxtest:~ # rmmod mptsas mptlinuxtest:~ # modprobe mptsas mptlinuxtest:~ # cat /proc/scsi/scsi Attached devices: Host: scsi3 Channel: 00 Id: 00 Lun: 00 Vendor: HP Model: DG072A9BB7 Rev: HPD0 Type: Direct-Access ANSI SCSI revision: 05 Host: scsi3 Channel: 00 Id: 01 Lun: 00 Vendor: HP Model: DG072A8B54 Rev: HPD4 Type: Direct-Access ANSI SCSI revision: 05 Host: scsi3 Channel: 01 Id: 03 Lun: 00 Vendor: LSILOGIC Model: Logical Volume Rev: 3000 Type: Direct-Access ANSI SCSI revision: 02 mptlinuxtest:~ # lsscsi -g [3:0:0:0] disk HP DG072A9BB7 HPD0 - /dev/sg0 [3:0:1:0] disk HP DG072A8B54 HPD4 - /dev/sg1 [3:1:3:0] disk LSILOGIC Logical Volume 3000 /dev/sda /dev/sg2 mptlinuxtest:~ # sleep 10 < /dev/sg2 & ( sleep 1 && echo scsi remove-single-device 3 1 3 0 > /proc/scsi/scsi ) [1] 797 mptlinuxtest:~ # [1]+ Done sleep 10 < /dev/sg2 mptlinuxtest:~ # echo $? 0 mptlinuxtest:~ # rmmod mptsas ERROR: Module mptsas is in use mptlinuxtest:~ # Also I tried using a C program rather than the sleep command, to remove the possibility of a read from stdin by sleep command (even though I think it doesn't, according to strace.) [root@slicer ~]# cat sleeptest.c #include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <errno.h> int main(int argc, char *argv[]) { int fd; fd = open(argv[1], O_RDONLY); if (fd < 0) { perror("open"); return 1; } sleep(10); return 0; } Using that, used in place of the "sleep < /dev/sg1", made no difference. -- steve > > Doug Gilbert > > > >Maybe it's my driver. Let me try with USB. > > > >[root@slicer ~]# cat /proc/scsi/scsi > >Attached devices: > >Host: scsi1 Channel: 00 Id: 00 Lun: 00 > > Vendor: USB Model: DISK 2.0 Rev: 0403 > > Type: Direct-Access ANSI SCSI revision: 00 > >[root@slicer ~]# lsmod | grep sd > >sd_mod 59592 0 > >scsi_mod 189304 9 > >usb_storage,ib_iser,iscsi_tcp,libiscsi,scsi_transport_iscsi,scsi_dh,sg,cciss,sd_mod > >[root@slicer ~]# rmmod usb_storage > >[root@slicer ~]# cat /proc/scsi/scsi > >Attached devices: > >[root@slicer ~]# modprobe usb_storage > >[root@slicer ~]# cat /proc/scsi/scsi > >Attached devices: > >[root@slicer ~]# echo scsi add-single-device 1 0 0 0 > /proc/scsi/scsi > >-bash: echo: write error: No such device or address > > > >Oh yeah, the host number increments, forgot about that... > > > >[root@slicer ~]# echo scsi add-single-device 2 0 0 0 > /proc/scsi/scsi > >[root@slicer ~]# cat /proc/scsi/scsi > >Attached devices: > >Host: scsi2 Channel: 00 Id: 00 Lun: 00 > > Vendor: USB Model: DISK 2.0 Rev: 0403 > > Type: Direct-Access ANSI SCSI revision: 00 > >[root@slicer ~]# lsscsi -g > >[2:0:0:0] disk USB DISK 2.0 0403 /dev/sda /dev/sg0 > >[root@slicer ~]# sleep 10 < /dev/sg0 & ( sleep 1 && echo scsi > >remove-single-device 2 0 0 0 > /proc/scsi/scsi ) > >[1] 6073 > >[root@slicer ~]# > >[root@slicer ~]# > >[1]+ Done sleep 10 < /dev/sg0 > >[root@slicer ~]# rmmod usb_storage > >ERROR: Module usb_storage is in use > >[root@slicer ~]# > > > >Hmm, same thing. > > > >Any thoughts? (other than "don't do that." Our array configuration > >utility for smart arrays is causing similar trouble, as it rapidly creates > >and deletes logical drives, etc. so it would be nice if this didn't > >happen.) -- 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
