From: Chuck Lever <chuck.lever@xxxxxxxxxx>
[ Upstream commit 35308e7f0fc3942edc87d9c6dc78c4a096428957 ]
To reduce contention on the bucket locks, we must avoid calling
kfree() while each bucket lock is held.
Start by refactoring nfsd_reply_cache_free_locked() into a helper
that removes an entry from the bucket (and must therefore run under
the lock) and a second helper that frees the entry (which does not
need to hold the lock).
For readability, rename the helpers nfsd_cacherep_<verb>.
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Stable-dep-of: a9507f6af145 ("NFSD: Replace nfsd_prune_bucket()")
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfsd/nfscache.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -110,21 +110,33 @@ nfsd_reply_cache_alloc(struct svc_rqst *
return rp;
}
+static void nfsd_cacherep_free(struct svc_cacherep *rp)
+{
+ if (rp->c_type == RC_REPLBUFF)
+ kfree(rp->c_replvec.iov_base);
+ kmem_cache_free(drc_slab, rp);
+}
+
static void
-nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
- struct nfsd_net *nn)
+nfsd_cacherep_unlink_locked(struct nfsd_net *nn, struct nfsd_drc_bucket *b,
+ struct svc_cacherep *rp)
{
- if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) {
+ if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base)
nfsd_stats_drc_mem_usage_sub(nn, rp->c_replvec.iov_len);
- kfree(rp->c_replvec.iov_base);
- }
if (rp->c_state != RC_UNUSED) {
rb_erase(&rp->c_node, &b->rb_head);
list_del(&rp->c_lru);
atomic_dec(&nn->num_drc_entries);
nfsd_stats_drc_mem_usage_sub(nn, sizeof(*rp));
}
- kmem_cache_free(drc_slab, rp);
+}
+
+static void
+nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
+ struct nfsd_net *nn)
+{
+ nfsd_cacherep_unlink_locked(nn, b, rp);
+ nfsd_cacherep_free(rp);
}
static void
@@ -132,8 +144,9 @@ nfsd_reply_cache_free(struct nfsd_drc_bu
struct nfsd_net *nn)
{
spin_lock(&b->cache_lock);
- nfsd_reply_cache_free_locked(b, rp, nn);
+ nfsd_cacherep_unlink_locked(nn, b, rp);
spin_unlock(&b->cache_lock);
+ nfsd_cacherep_free(rp);
}
int nfsd_drc_slab_create(void)
Patches currently in stable-queue which might be from cel@xxxxxxxxxx are
queue-5.10/nfsd-rename-nfsd_net_-to-nfsd_stats_.patch
queue-5.10/nfsd-rename-nfsd_reply_cache_alloc.patch
queue-5.10/nfsd-simplify-error-paths-in-nfsd_svc.patch
queue-5.10/sunrpc-pass-in-the-sv_stats-struct-through-svc_create_pooled.patch
queue-5.10/nfsd-move-init-of-percpu-reply_cache_stats-counters-back-to-nfsd_init_net.patch
queue-5.10/sunrpc-use-the-struct-net-as-the-svc-proc-private.patch
queue-5.10/nfsd-rewrite-synopsis-of-nfsd_percpu_counters_init.patch
queue-5.10/nfsd-replace-nfsd_prune_bucket.patch
queue-5.10/nfsd-refactor-the-duplicate-reply-cache-shrinker.patch
queue-5.10/sunrpc-remove-pg_stats-from-svc_program.patch
queue-5.10/nfsd-make-all-of-the-nfsd-stats-per-network-namespace.patch
queue-5.10/nfsd-fix-frame-size-warning-in-svc_export_parse.patch
queue-5.10/nfsd-expose-proc-net-sunrpc-nfsd-in-net-namespaces.patch
queue-5.10/nfsd-move-reply-cache-initialization-into-nfsd-startup.patch
queue-5.10/nfsd-remove-nfsd_stats-make-th_cnt-a-global-counter.patch
queue-5.10/nfsd-make-svc_stat-per-network-namespace-instead-of-global.patch
queue-5.10/sunrpc-don-t-change-sv_stats-if-it-doesn-t-exist.patch
queue-5.10/nfsd-refactor-nfsd_reply_cache_free_locked.patch
queue-5.10/nfsd-stop-setting-pg_stats-for-unused-stats.patch
