Merge git://git.kvack.org/~bcrl/aio-fixes
Pull another aio fix from Ben LaHaise:
"put_reqs_available() can now be called from within irq context, which
means that it (and its sibling function get_reqs_available()) now need
to be irq-safe, not just preempt-safe"
* git://git.kvack.org/~bcrl/aio-fixes:
aio: protect reqs_available updates from changes in interrupt handlers
diff --git a/fs/aio.c b/fs/aio.c
index 955947e..1c9c5f0 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -830,16 +830,20 @@
static void put_reqs_available(struct kioctx *ctx, unsigned nr)
{
struct kioctx_cpu *kcpu;
+ unsigned long flags;
preempt_disable();
kcpu = this_cpu_ptr(ctx->cpu);
+ local_irq_save(flags);
kcpu->reqs_available += nr;
+
while (kcpu->reqs_available >= ctx->req_batch * 2) {
kcpu->reqs_available -= ctx->req_batch;
atomic_add(ctx->req_batch, &ctx->reqs_available);
}
+ local_irq_restore(flags);
preempt_enable();
}
@@ -847,10 +851,12 @@
{
struct kioctx_cpu *kcpu;
bool ret = false;
+ unsigned long flags;
preempt_disable();
kcpu = this_cpu_ptr(ctx->cpu);
+ local_irq_save(flags);
if (!kcpu->reqs_available) {
int old, avail = atomic_read(&ctx->reqs_available);
@@ -869,6 +875,7 @@
ret = true;
kcpu->reqs_available--;
out:
+ local_irq_restore(flags);
preempt_enable();
return ret;
}
