From: Jeff Layton <jlayton@kernel.org>
To: Chuck Lever <chuck.lever@oracle.com>, NeilBrown <neil@brown.name>,
Olga Kornievskaia <okorniev@redhat.com>,
Dai Ngo <Dai.Ngo@oracle.com>, Tom Talpey <tom@talpey.com>,
Trond Myklebust <trondmy@kernel.org>,
Anna Schumaker <anna@kernel.org>
Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeff Layton <jlayton@kernel.org>
Subject: [PATCH v2 2/4] sunrpc: convert queue_lock from global spinlock to per-cache-detail lock
Date: Mon, 23 Feb 2026 12:09:59 -0500 [thread overview]
Message-ID: <20260223-sunrpc-cache-v2-2-91fc827c4d33@kernel.org> (raw)
In-Reply-To: <20260223-sunrpc-cache-v2-0-91fc827c4d33@kernel.org>
The global queue_lock serializes all upcall queue operations across
every cache_detail instance. Convert it to a per-cache-detail spinlock
so that different caches (e.g. auth.unix.ip vs nfsd.fh) no longer
contend with each other on queue operations.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
include/linux/sunrpc/cache.h | 1 +
net/sunrpc/cache.c | 47 ++++++++++++++++++++++----------------------
2 files changed, 24 insertions(+), 24 deletions(-)
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index e783132e481ff2593fdc5d323f7b3a08f85d4cd8..3d32dd1f7b05d35562d2064fed69877b3950fb51 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -113,6 +113,7 @@ struct cache_detail {
/* fields for communication over channel */
struct list_head queue;
+ spinlock_t queue_lock;
atomic_t writers; /* how many time is /channel open */
time64_t last_close; /* if no writers, when did last close */
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 86b3fd5a429d77f7f917f398a02cb7a5ff8dd1e0..1cfaae488c6c67a9797511804e4bbba16bcc70ae 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -400,6 +400,7 @@ void sunrpc_init_cache_detail(struct cache_detail *cd)
{
spin_lock_init(&cd->hash_lock);
INIT_LIST_HEAD(&cd->queue);
+ spin_lock_init(&cd->queue_lock);
spin_lock(&cache_list_lock);
cd->nextcheck = 0;
cd->entries = 0;
@@ -803,8 +804,6 @@ void cache_clean_deferred(void *owner)
*
*/
-static DEFINE_SPINLOCK(queue_lock);
-
struct cache_queue {
struct list_head list;
int reader; /* if 0, then request */
@@ -847,7 +846,7 @@ static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
inode_lock(inode); /* protect against multiple concurrent
* readers on this file */
again:
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
/* need to find next request */
while (rp->q.list.next != &cd->queue &&
list_entry(rp->q.list.next, struct cache_queue, list)
@@ -856,7 +855,7 @@ static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
list_move(&rp->q.list, next);
}
if (rp->q.list.next == &cd->queue) {
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
inode_unlock(inode);
WARN_ON_ONCE(rp->offset);
return 0;
@@ -865,7 +864,7 @@ static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
WARN_ON_ONCE(rq->q.reader);
if (rp->offset == 0)
rq->readers++;
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
if (rq->len == 0) {
err = cache_request(cd, rq);
@@ -876,9 +875,9 @@ static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) {
err = -EAGAIN;
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
list_move(&rp->q.list, &rq->q.list);
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
} else {
if (rp->offset + count > rq->len)
count = rq->len - rp->offset;
@@ -888,26 +887,26 @@ static ssize_t cache_read(struct file *filp, char __user *buf, size_t count,
rp->offset += count;
if (rp->offset >= rq->len) {
rp->offset = 0;
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
list_move(&rp->q.list, &rq->q.list);
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
}
err = 0;
}
out:
if (rp->offset == 0) {
/* need to release rq */
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
rq->readers--;
if (rq->readers == 0 &&
!test_bit(CACHE_PENDING, &rq->item->flags)) {
list_del(&rq->q.list);
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
cache_put(rq->item, cd);
kfree(rq->buf);
kfree(rq);
} else
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
}
if (err == -EAGAIN)
goto again;
@@ -988,7 +987,7 @@ static __poll_t cache_poll(struct file *filp, poll_table *wait,
if (!rp)
return mask;
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
for (cq= &rp->q; &cq->list != &cd->queue;
cq = list_entry(cq->list.next, struct cache_queue, list))
@@ -996,7 +995,7 @@ static __poll_t cache_poll(struct file *filp, poll_table *wait,
mask |= EPOLLIN | EPOLLRDNORM;
break;
}
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
return mask;
}
@@ -1011,7 +1010,7 @@ static int cache_ioctl(struct inode *ino, struct file *filp,
if (cmd != FIONREAD || !rp)
return -EINVAL;
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
/* only find the length remaining in current request,
* or the length of the next request
@@ -1024,7 +1023,7 @@ static int cache_ioctl(struct inode *ino, struct file *filp,
len = cr->len - rp->offset;
break;
}
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
return put_user(len, (int __user *)arg);
}
@@ -1046,9 +1045,9 @@ static int cache_open(struct inode *inode, struct file *filp,
rp->offset = 0;
rp->q.reader = 1;
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
list_add(&rp->q.list, &cd->queue);
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
}
if (filp->f_mode & FMODE_WRITE)
atomic_inc(&cd->writers);
@@ -1064,7 +1063,7 @@ static int cache_release(struct inode *inode, struct file *filp,
if (rp) {
struct cache_request *rq = NULL;
- spin_lock(&queue_lock);
+ spin_lock(&cd->queue_lock);
if (rp->offset) {
struct cache_queue *cq;
for (cq = &rp->q; &cq->list != &cd->queue;
@@ -1086,7 +1085,7 @@ static int cache_release(struct inode *inode, struct file *filp,
rp->offset = 0;
}
list_del(&rp->q.list);
- spin_unlock(&queue_lock);
+ spin_unlock(&cd->queue_lock);
if (rq) {
cache_put(rq->item, cd);
@@ -1113,7 +1112,7 @@ static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
struct cache_request *cr;
LIST_HEAD(dequeued);
- spin_lock(&queue_lock);
+ spin_lock(&detail->queue_lock);
list_for_each_entry_safe(cq, tmp, &detail->queue, list)
if (!cq->reader) {
cr = container_of(cq, struct cache_request, q);
@@ -1126,7 +1125,7 @@ static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
continue;
list_move(&cr->q.list, &dequeued);
}
- spin_unlock(&queue_lock);
+ spin_unlock(&detail->queue_lock);
while (!list_empty(&dequeued)) {
cr = list_entry(dequeued.next, struct cache_request, q.list);
list_del(&cr->q.list);
@@ -1251,7 +1250,7 @@ static int cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
crq->buf = buf;
crq->len = 0;
crq->readers = 0;
- spin_lock(&queue_lock);
+ spin_lock(&detail->queue_lock);
if (test_bit(CACHE_PENDING, &h->flags)) {
crq->item = cache_get(h);
list_add_tail(&crq->q.list, &detail->queue);
@@ -1259,7 +1258,7 @@ static int cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
} else
/* Lost a race, no longer PENDING, so don't enqueue */
ret = -EAGAIN;
- spin_unlock(&queue_lock);
+ spin_unlock(&detail->queue_lock);
wake_up(&queue_wait);
if (ret == -EAGAIN) {
kfree(buf);
--
2.53.0
next prev parent reply other threads:[~2026-02-23 17:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-23 17:09 [PATCH v2 0/4] sunrpc: cache infrastructure scalability improvements Jeff Layton
2026-02-23 17:09 ` [PATCH v2 1/4] sunrpc: fix cache_request leak in cache_release Jeff Layton
2026-02-23 17:09 ` Jeff Layton [this message]
2026-02-23 17:10 ` [PATCH v2 3/4] sunrpc: convert queue_wait from global to per-cache-detail waitqueue Jeff Layton
2026-02-23 17:10 ` [PATCH v2 4/4] sunrpc: split cache_detail queue into request and reader lists Jeff Layton
2026-02-23 21:09 ` [PATCH v2 0/4] sunrpc: cache infrastructure scalability improvements Chuck Lever
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260223-sunrpc-cache-v2-2-91fc827c4d33@kernel.org \
--to=jlayton@kernel.org \
--cc=Dai.Ngo@oracle.com \
--cc=anna@kernel.org \
--cc=chuck.lever@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=neil@brown.name \
--cc=okorniev@redhat.com \
--cc=tom@talpey.com \
--cc=trondmy@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox