[PATCH 06/19] staging: lustre: introduce and use l_wait_event_abortable()

NeilBrown
2018-01-08T03:29:52Z

lustre sometimes wants to wait for an event, but abort if
one of a specific list of signals arrives. This is a little
bit like wait_event_killable(), except that the signals are
identified a different way.

So introduce l_wait_event_abortable() which provides this
functionality.
Having separate functions for separate needs is more in line
with the pattern set by include/linux/wait.h, than having a
single function which tries to include all possible needs.

Also introduce l_wait_event_abortable_exclusive().

Note that l_wait_event() return -EINTR on a signal, while
Linux wait_event functions return -ERESTARTSYS.
l_wait_event_{abortable_,}exclusive follow the Linux pattern.

Signed-off-by: NeilBrown <neilb@suse.com>
---
drivers/staging/lustre/lustre/include/lustre_lib.h | 24 ++++++++++++++++++++
drivers/staging/lustre/lustre/ldlm/ldlm_resource.c | 12 +++++-----
drivers/staging/lustre/lustre/llite/llite_lib.c | 12 +++-------
drivers/staging/lustre/lustre/obdclass/genops.c | 9 +++-----
drivers/staging/lustre/lustre/obdclass/llog_obd.c | 5 ++--
drivers/staging/lustre/lustre/osc/osc_page.c | 6 ++---
drivers/staging/lustre/lustre/osc/osc_request.c | 6 ++---
7 files changed, 43 insertions(+), 31 deletions(-)

diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h
index 7d950c53e962..b2a64d0e682c 100644
--- a/drivers/staging/lustre/lustre/include/lustre_lib.h
+++ b/drivers/staging/lustre/lustre/include/lustre_lib.h
@@ -336,4 +336,28 @@ do { \
/** @} lib */

+
+/* l_wait_event_abortable() is a bit like wait_event_killable()
+ * except there is a fixed set of signals which will abort:
+ * LUSTRE_FATAL_SIGS
+ */
+#define l_wait_event_abortable(wq, condition) \
+({ \
+ sigset_t __blocked; \
+ int __ret = 0; \
+ __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
+ __ret = wait_event_interruptible(wq, condition); \
+ cfs_restore_sigs(__blocked); \
+ __ret; \
+})
+
+#define l_wait_event_abortable_exclusive(wq, condition) \
+({ \
+ sigset_t __blocked; \
+ int __ret = 0; \
+ __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
+ __ret = wait_event_interruptible_exclusive(wq, condition); \
+ cfs_restore_sigs(__blocked); \
+ __ret; \
+})
#endif /* _LUSTRE_LIB_H */
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_resource.c b/drivers/staging/lustre/lustre/ldlm/ldlm_resource.c
index 2e66825c8f4b..4c44603ab6f9 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_resource.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_resource.c
@@ -879,7 +879,6 @@ static int __ldlm_namespace_free(struct ldlm_namespace *ns, int force)
ldlm_namespace_cleanup(ns, force ? LDLM_FL_LOCAL_ONLY : 0);

if (atomic_read(&ns->ns_bref) > 0) {
- struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
int rc;

CDEBUG(D_DLMTRACE,
@@ -887,11 +886,12 @@ static int __ldlm_namespace_free(struct ldlm_namespace *ns, int force)
ldlm_ns_name(ns), atomic_read(&ns->ns_bref));
force_wait:
if (force)
- lwi = LWI_TIMEOUT(msecs_to_jiffies(obd_timeout *
- MSEC_PER_SEC) / 4, NULL, NULL);
-
- rc = l_wait_event(ns->ns_waitq,
- atomic_read(&ns->ns_bref) == 0, &lwi);
+ rc = wait_event_idle_timeout(ns->ns_waitq,
+ atomic_read(&ns->ns_bref) == 0,
+ obd_timeout * HZ / 4) ? 0 : -ETIMEDOUT;
+ else
+ rc = l_wait_event_abortable(ns->ns_waitq,
+ atomic_read(&ns->ns_bref) == 0);

/* Forced cleanups should be able to reclaim all references,
* so it's safe to wait forever... we can't leak locks...
diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index 0a9183f271f5..33dc15e9aebb 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -986,16 +986,12 @@ void ll_put_super(struct super_block *sb)
}

/* Wait for unstable pages to be committed to stable storage */
- if (!force) {
- struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
-
- rc = l_wait_event(sbi->ll_cache->ccc_unstable_waitq,
- !atomic_long_read(&sbi->ll_cache->ccc_unstable_nr),
- &lwi);
- }
+ if (!force)
+ rc = l_wait_event_abortable(sbi->ll_cache->ccc_unstable_waitq,
+ !atomic_long_read(&sbi->ll_cache->ccc_unstable_nr));

ccc_count = atomic_long_read(&sbi->ll_cache->ccc_unstable_nr);
- if (!force && rc != -EINTR)
+ if (!force && rc != -ERESTARTSYS)
LASSERTF(!ccc_count, "count: %li\n", ccc_count);

/* We need to set force before the lov_disconnect in
diff --git a/drivers/staging/lustre/lustre/obdclass/genops.c b/drivers/staging/lustre/lustre/obdclass/genops.c
index 3ff25b8d3b48..8f776a4058a9 100644
--- a/drivers/staging/lustre/lustre/obdclass/genops.c
+++ b/drivers/staging/lustre/lustre/obdclass/genops.c
@@ -1332,7 +1332,6 @@ static bool obd_request_slot_avail(struct client_obd *cli,
int obd_get_request_slot(struct client_obd *cli)
{
struct obd_request_slot_waiter orsw;
- struct l_wait_info lwi;
int rc;

spin_lock(&cli->cl_loi_list_lock);
@@ -1347,11 +1346,9 @@ int obd_get_request_slot(struct client_obd *cli)
orsw.orsw_signaled = false;
spin_unlock(&cli->cl_loi_list_lock);

- lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
- rc = l_wait_event(orsw.orsw_waitq,
- obd_request_slot_avail(cli, &orsw) ||
- orsw.orsw_signaled,
- &lwi);
+ rc = l_wait_event_abortable(orsw.orsw_waitq,
+ obd_request_slot_avail(cli, &orsw) ||
+ orsw.orsw_signaled);

/*
* Here, we must take the lock to avoid the on-stack 'orsw' to be
diff --git a/drivers/staging/lustre/lustre/obdclass/llog_obd.c b/drivers/staging/lustre/lustre/obdclass/llog_obd.c
index 28bbaa2136ac..26aea114a29b 100644
--- a/drivers/staging/lustre/lustre/obdclass/llog_obd.c
+++ b/drivers/staging/lustre/lustre/obdclass/llog_obd.c
@@ -104,7 +104,6 @@ EXPORT_SYMBOL(__llog_ctxt_put);

int llog_cleanup(const struct lu_env *env, struct llog_ctxt *ctxt)
{
- struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
struct obd_llog_group *olg;
int rc, idx;

@@ -129,8 +128,8 @@ int llog_cleanup(const struct lu_env *env, struct llog_ctxt *ctxt)
CERROR("Error %d while cleaning up ctxt %p\n",
rc, ctxt);

- l_wait_event(olg->olg_waitq,
- llog_group_ctxt_null(olg, idx), &lwi);
+ l_wait_event_abortable(olg->olg_waitq,
+ llog_group_ctxt_null(olg, idx));

return rc;
}
diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c
index 20094b6309f9..6fdd521feb21 100644
--- a/drivers/staging/lustre/lustre/osc/osc_page.c
+++ b/drivers/staging/lustre/lustre/osc/osc_page.c
@@ -759,7 +759,6 @@ static long osc_lru_reclaim(struct client_obd *cli, unsigned long npages)
static int osc_lru_alloc(const struct lu_env *env, struct client_obd *cli,
struct osc_page *opg)
{
- struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
struct osc_io *oio = osc_env_io(env);
int rc = 0;

@@ -782,9 +781,8 @@ static int osc_lru_alloc(const struct lu_env *env, struct client_obd *cli,

cond_resched();

- rc = l_wait_event(osc_lru_waitq,
- atomic_long_read(cli->cl_lru_left) > 0,
- &lwi);
+ rc = l_wait_event_abortable(osc_lru_waitq,
+ atomic_long_read(cli->cl_lru_left) > 0);

if (rc < 0)
break;
diff --git a/drivers/staging/lustre/lustre/osc/osc_request.c b/drivers/staging/lustre/lustre/osc/osc_request.c
index 45b1ebf33363..074b5ce6284c 100644
--- a/drivers/staging/lustre/lustre/osc/osc_request.c
+++ b/drivers/staging/lustre/lustre/osc/osc_request.c
@@ -552,14 +552,12 @@ static int osc_destroy(const struct lu_env *env, struct obd_export *exp,

req->rq_interpret_reply = osc_destroy_interpret;
if (!osc_can_send_destroy(cli)) {
- struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
-
/*
* Wait until the number of on-going destroy RPCs drops
* under max_rpc_in_flight
*/
- l_wait_event_exclusive(cli->cl_destroy_waitq,
- osc_can_send_destroy(cli), &lwi);
+ l_wait_event_abortable_exclusive(cli->cl_destroy_waitq,
+ osc_can_send_destroy(cli));
}

/* Do not wait for response */