alistair23-linux/drivers/scsi/cxlflash
Manoj N. Kumar f411396d94 cxlflash: Fix to drain operations from previous reset
While running 'sg_reset -H' in a loop with a user-space application active,
hit the following exception:

cpu 0x2: Vector: 300 (Data Access)
    pc: : afu_attach+0x50/0x240 [cxlflash]
    lr: : cxlflash_afu_recover+0x3dc/0x7d0 [cxlflash]
    pid   = 20365, comm = run_block_fvt

Linux version 4.5.0-491-26f710d+

cxlflash_afu_recover+0x3dc/0x7d0 [cxlflash]
cxlflash_ioctl+0x5a8/0x6f0 [cxlflash]
scsi_ioctl+0x3b0/0x4c0
sd_ioctl+0x110/0x190
blkdev_ioctl+0x28c/0xc20
block_ioctl+0xa4/0xd0
do_vfs_ioctl+0xd8/0x8c0
SyS_ioctl+0xd4/0xf0
system_call+0x38/0xb4

The problem here is that the problem space area is unmapped while the
application issues the DK_CXLFLASH_RECOVER_AFU ioctl.

This is the order I observe:

proc1				proc2
1) sg_reset
				2) ioctl(DK_CXLFLASH_RECOVER_AFU)
3) sg_reset again
   causing a PSA unmap
				4) continues RECOVER_AFU processing

The resolution to this problem is to have the reset handler drain all
outstanding user space initiated ioctls before proceeding.  It is safe
to drain after the state has been changed to STATE_RESET. Also since
drain_ioctls() was static, it had to be moved up a bit to be before
cxlflash_eh_host_reset_handler().

Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-07-12 23:16:31 -04:00
..
common.h powerpc updates for 4.6 2016-03-19 15:38:41 -07:00
Kconfig
lunmgt.c cxlflash: Fix to avoid corrupting port selection mask 2015-10-30 17:23:55 +09:00
main.c cxlflash: Fix to drain operations from previous reset 2016-07-12 23:16:31 -04:00
main.h cxlflash: Fix regression issue with re-ordering patch 2016-03-28 20:43:17 -04:00
Makefile cxlflash: Virtual LUN support 2015-08-26 18:05:39 -07:00
sislite.h cxlflash: Correct spelling, grammar, and alignment mistakes 2015-10-30 17:18:28 +09:00
superpipe.c cxlflash: Fix to resolve dead-lock during EEH recovery 2016-05-05 21:02:17 -04:00
superpipe.h cxlflash: Split out context initialization 2016-03-08 21:17:33 -05:00
vlun.c cxlflash: Fix to avoid virtual LUN failover failure 2016-01-06 20:50:08 -05:00
vlun.h cxlflash: Virtual LUN support 2015-08-26 18:05:39 -07:00