Commit 9048cf05 authored by Olga Kornievskaia's avatar Olga Kornievskaia Committed by Chuck Lever
Browse files

NFSD: fix management of pending async copies 



Currently the pending_async_copies count is decremented just
before a struct nfsd4_copy is destroyed. After commit aa0ebd21
("NFSD: Add nfsd4_copy time-to-live") nfsd4_copy structures sticks
around for 10 lease periods after the COPY itself has completed,
the pending_async_copies count stays high for a long time. This
causes NFSD to avoid the use of background copy even though the
actual background copy workload might no longer be running.

In this patch, decrement pending_async_copies once async copy thread
is done processing the copy work.

Fixes: aa0ebd21 ("NFSD: Add nfsd4_copy time-to-live")
Signed-off-by: default avatarOlga Kornievskaia <okorniev@redhat.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 69d803c4

fs/nfsd/nfs4proc.c

+8 −5
Original line number Diff line number Diff line
@@ -1347,7 +1347,6 @@ static void nfs4_put_copy(struct nfsd4_copy *copy) 
{

	if (!refcount_dec_and_test(&copy->refcount))

		return;

	atomic_dec(&copy->cp_nn->pending_async_copies);

	kfree(copy->cp_src);

	kfree(copy);

}
@@ -1870,6 +1869,7 @@ static int nfsd4_do_async_copy(void *data) 
	set_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_flags);

	trace_nfsd_copy_async_done(copy);

	nfsd4_send_cb_offload(copy);

	atomic_dec(&copy->cp_nn->pending_async_copies);

	return 0;

}
@@ -1927,19 +1927,19 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
		/* Arbitrary cap on number of pending async copy operations */

		if (atomic_inc_return(&nn->pending_async_copies) >

				(int)rqstp->rq_pool->sp_nrthreads)

			goto out_err;

			goto out_dec_async_copy_err;

		async_copy->cp_src = kmalloc(sizeof(*async_copy->cp_src), GFP_KERNEL);

		if (!async_copy->cp_src)

			goto out_err;

			goto out_dec_async_copy_err;

		if (!nfs4_init_copy_state(nn, copy))

			goto out_err;

			goto out_dec_async_copy_err;

		memcpy(&result->cb_stateid, &copy->cp_stateid.cs_stid,

			sizeof(result->cb_stateid));

		dup_copy_fields(copy, async_copy);

		async_copy->copy_task = kthread_create(nfsd4_do_async_copy,

				async_copy, "%s", "copy thread");

		if (IS_ERR(async_copy->copy_task))

			goto out_err;

			goto out_dec_async_copy_err;

		spin_lock(&async_copy->cp_clp->async_lock);

		list_add(&async_copy->copies,

				&async_copy->cp_clp->async_copies);
@@ -1954,6 +1954,9 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	trace_nfsd_copy_done(copy, status);

	release_copy_files(copy);

	return status;

out_dec_async_copy_err:

	if (async_copy)

		atomic_dec(&nn->pending_async_copies);

out_err:

	if (nfsd4_ssc_is_inter(copy)) {

		/*