Currently, scsi_dh_alua fails I/O requests early on once ALUA state
unavailable/standby occur, which prevents path checkers to actually
check if I/O still fails or now works.
Then I/O requests are blocked indefinitely due to queue_if_no_path
but the underlying individual paths are fully operational, and can
be verified as such otherways (e.g., SG_IO).
This patchset addresses that problem, and adds a few improvements
to the logging of PG state changes.
Patch 1 fixes the problem.
Patch 2 makes sure that state changes for all PGs are logged.
Patch 3 makes sure that state no-changes for PGs in unavailable/standby
are not logged - only changes are.
Patch 4 adds few sdev_dbg() calls to track the path to alua_rtpg_work()
Tested on v4.12+ (commit b4b8cbf679c4).
Mauricio Faria de Oliveira (4):
scsi: scsi_dh_alua: allow I/O in target port unavailable and standby
states
scsi: scsi_dh_alua: print changes to RTPG state of all PGs
scsi: scsi_dh_alua: do not print RTPG state if it remains
unavailable/standby
scsi: scsi_dh_alua: add sdev_dbg() to track alua_rtpg_work()
drivers/scsi/device_handler/scsi_dh_alua.c | 129 +++++++++++++++++++++++++----
1 file changed, 113 insertions(+), 16 deletions(-)
--
1.8.3.1
