forked from Minki/linux
760bf578ed
This fixes the following races:
1. core_alua_do_transition_tg_pt could have read
tg_pt_gp_alua_access_state and gone into this if chunk:
if (!explicit &&
atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==
ALUA_ACCESS_STATE_TRANSITION) {
and then core_alua_do_transition_tg_pt_work could update the
state. core_alua_do_transition_tg_pt would then only set
tg_pt_gp_alua_pending_state and the tg_pt_gp_alua_access_state would
not get updated with the second calls state.
2. core_alua_do_transition_tg_pt could be setting
tg_pt_gp_transition_complete while the tg_pt_gp_transition_work
is already completing. core_alua_do_transition_tg_pt then waits on the
completion that will never be called.
To handle these issues, we just call flush_work which will return when
core_alua_do_transition_tg_pt_work has completed so there is no need
to do the complete/wait. And, if core_alua_do_transition_tg_pt_work
was running, instead of trying to sneak in the state change, we just
schedule up another core_alua_do_transition_tg_pt_work call.
Note that this does not handle a possible race where there are multiple
threads call core_alua_do_transition_tg_pt at the same time. I think
we need a mutex in target_tg_pt_gp_alua_access_state_store.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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| .. | ||
| iscsi | ||
| loopback | ||
| sbp | ||
| tcm_fc | ||
| Kconfig | ||
| Makefile | ||
| target_core_alua.c | ||
| target_core_alua.h | ||
| target_core_configfs.c | ||
| target_core_device.c | ||
| target_core_fabric_configfs.c | ||
| target_core_fabric_lib.c | ||
| target_core_file.c | ||
| target_core_file.h | ||
| target_core_hba.c | ||
| target_core_iblock.c | ||
| target_core_iblock.h | ||
| target_core_internal.h | ||
| target_core_pr.c | ||
| target_core_pr.h | ||
| target_core_pscsi.c | ||
| target_core_pscsi.h | ||
| target_core_rd.c | ||
| target_core_rd.h | ||
| target_core_sbc.c | ||
| target_core_spc.c | ||
| target_core_stat.c | ||
| target_core_tmr.c | ||
| target_core_tpg.c | ||
| target_core_transport.c | ||
| target_core_ua.c | ||
| target_core_ua.h | ||
| target_core_user.c | ||
| target_core_xcopy.c | ||
| target_core_xcopy.h | ||