xprt_alloc_slot will call rpc_delay() to make the task wait a bit before
retrying when it gets back an -ENOMEM error from xprt_dynamic_alloc_slot.
The problem there is that rpc_delay does this:
rpc_sleep_on(&delay_queue, task, __rpc_atrun);
...and __rpc_atrun will reset the task->tk_status back to 0 when the
task wakes back up. This makes call_reserveresult abort the task with
-EIO.
The RH QA group discovered this problem when testing with low-memory
clients and this patch fixed it:
https://bugzilla.redhat.com/show_bug.cgi?id=822189
Fix this by adding a new rpc_delay_action() variant that makes allows
us to pass in a rpc_action to reset the status back to -EAGAIN instead.
Cc: Andy Adamson <andros@xxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
include/linux/sunrpc/sched.h | 1 +
net/sunrpc/sched.c | 9 +++++++--
net/sunrpc/xprt.c | 7 ++++++-
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index dc0c3cc..6cafdbb 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -241,6 +241,7 @@ struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *,
void *);
void rpc_wake_up_status(struct rpc_wait_queue *, int);
int rpc_queue_empty(struct rpc_wait_queue *);
+void rpc_delay_action(struct rpc_task *, unsigned long, rpc_action);
void rpc_delay(struct rpc_task *, unsigned long);
void * rpc_malloc(struct rpc_task *, size_t);
void rpc_free(void *);
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 994cfea..f2ff98d 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -613,13 +613,18 @@ static void __rpc_atrun(struct rpc_task *task)
task->tk_status = 0;
}
+void rpc_delay_action(struct rpc_task *task, unsigned long delay, rpc_action action)
+{
+ task->tk_timeout = delay;
+ rpc_sleep_on(&delay_queue, task, action);
+}
+
/*
* Run a task at a later time
*/
void rpc_delay(struct rpc_task *task, unsigned long delay)
{
- task->tk_timeout = delay;
- rpc_sleep_on(&delay_queue, task, __rpc_atrun);
+ rpc_delay_action(task, delay, __rpc_atrun);
}
EXPORT_SYMBOL_GPL(rpc_delay);
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index b239e75..a5dc816 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -969,6 +969,11 @@ static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
return false;
}
+static void xprt_alloc_delay_reset_status(struct rpc_task *task)
+{
+ task->tk_status = -EAGAIN;
+}
+
static void xprt_alloc_slot(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_xprt;
@@ -984,7 +989,7 @@ static void xprt_alloc_slot(struct rpc_task *task)
goto out_init_req;
switch (PTR_ERR(req)) {
case -ENOMEM:
- rpc_delay(task, HZ >> 2);
+ rpc_delay_action(task, HZ >> 2, xprt_alloc_delay_reset_status);
dprintk("RPC: dynamic allocation of request slot "
"failed! Retrying\n");
break;
--
1.7.7.6
--
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