From: Christoph Hellwig <hch@lst.de>
To: Trond Myklebust <trondmy@kernel.org>
Cc: Anna Schumaker <anna@kernel.org>,
linux-nfs@vger.kernel.org, Jeff Layton <jlayton@kernel.org>
Subject: [PATCH 4/5] NFS: track active delegations per-server
Date: Fri, 18 Jul 2025 10:14:49 +0200 [thread overview]
Message-ID: <20250718081509.2607553-5-hch@lst.de> (raw)
In-Reply-To: <20250718081509.2607553-1-hch@lst.de>
The active delegation watermark was added to avoid overloading servers.
Track the active delegation per-server instead of globally so that clients
talking to multiple servers aren't limited by the global limit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
---
fs/nfs/client.c | 1 +
fs/nfs/delegation.c | 35 +++++++++++++++++++----------------
include/linux/nfs_fs_sb.h | 1 +
3 files changed, 21 insertions(+), 16 deletions(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 47258dc3af70..e13eb429b8b5 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1005,6 +1005,7 @@ struct nfs_server *nfs_alloc_server(void)
INIT_LIST_HEAD(&server->ss_src_copies);
atomic_set(&server->active, 0);
+ atomic_long_set(&server->nr_active_delegations, 0);
server->io_stats = nfs_alloc_iostats();
if (!server->io_stats) {
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 5f85966d7709..ea96f77e38c2 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -27,7 +27,6 @@
#define NFS_DEFAULT_DELEGATION_WATERMARK (5000U)
-static atomic_long_t nfs_active_delegations;
static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK;
module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);
@@ -38,11 +37,12 @@ static void __nfs_free_delegation(struct nfs_delegation *delegation)
kfree_rcu(delegation, rcu);
}
-static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation)
+static void nfs_mark_delegation_revoked(struct nfs_server *server,
+ struct nfs_delegation *delegation)
{
if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
delegation->stateid.type = NFS4_INVALID_STATEID_TYPE;
- atomic_long_dec(&nfs_active_delegations);
+ atomic_long_dec(&server->nr_active_delegations);
if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
nfs_clear_verifier_delegated(delegation->inode);
}
@@ -60,9 +60,10 @@ static void nfs_put_delegation(struct nfs_delegation *delegation)
__nfs_free_delegation(delegation);
}
-static void nfs_free_delegation(struct nfs_delegation *delegation)
+static void nfs_free_delegation(struct nfs_server *server,
+ struct nfs_delegation *delegation)
{
- nfs_mark_delegation_revoked(delegation);
+ nfs_mark_delegation_revoked(server, delegation);
nfs_put_delegation(delegation);
}
@@ -261,7 +262,7 @@ void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
}
clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
if (test_and_clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
- atomic_long_inc(&nfs_active_delegations);
+ atomic_long_inc(&NFS_SERVER(inode)->nr_active_delegations);
spin_unlock(&delegation->lock);
rcu_read_unlock();
put_cred(oldcred);
@@ -413,7 +414,8 @@ nfs_update_delegation_cred(struct nfs_delegation *delegation,
}
static void
-nfs_update_inplace_delegation(struct nfs_delegation *delegation,
+nfs_update_inplace_delegation(struct nfs_server *server,
+ struct nfs_delegation *delegation,
const struct nfs_delegation *update)
{
if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
@@ -426,7 +428,7 @@ nfs_update_inplace_delegation(struct nfs_delegation *delegation,
nfs_update_delegation_cred(delegation, update->cred);
/* smp_mb__before_atomic() is implicit due to xchg() */
clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
- atomic_long_inc(&nfs_active_delegations);
+ atomic_long_inc(&server->nr_active_delegations);
}
}
}
@@ -481,7 +483,7 @@ int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
if (nfs4_stateid_match_other(&old_delegation->stateid,
&delegation->stateid)) {
spin_lock(&old_delegation->lock);
- nfs_update_inplace_delegation(old_delegation,
+ nfs_update_inplace_delegation(server, old_delegation,
delegation);
spin_unlock(&old_delegation->lock);
goto out;
@@ -530,7 +532,7 @@ int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
rcu_assign_pointer(nfsi->delegation, delegation);
delegation = NULL;
- atomic_long_inc(&nfs_active_delegations);
+ atomic_long_inc(&server->nr_active_delegations);
trace_nfs4_set_delegation(inode, type);
@@ -544,7 +546,7 @@ int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
__nfs_free_delegation(delegation);
if (freeme != NULL) {
nfs_do_return_delegation(inode, freeme, 0);
- nfs_free_delegation(freeme);
+ nfs_free_delegation(server, freeme);
}
return status;
}
@@ -756,7 +758,7 @@ void nfs_inode_evict_delegation(struct inode *inode)
set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
nfs_do_return_delegation(inode, delegation, 1);
- nfs_free_delegation(delegation);
+ nfs_free_delegation(NFS_SERVER(inode), delegation);
}
}
@@ -842,7 +844,8 @@ void nfs4_inode_return_delegation_on_close(struct inode *inode)
if (!delegation)
goto out;
if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) ||
- atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) {
+ atomic_long_read(&NFS_SERVER(inode)->nr_active_delegations) >=
+ nfs_delegation_watermark) {
spin_lock(&delegation->lock);
if (delegation->inode &&
list_empty(&NFS_I(inode)->open_files) &&
@@ -1018,7 +1021,7 @@ static void nfs_revoke_delegation(struct inode *inode,
}
spin_unlock(&delegation->lock);
}
- nfs_mark_delegation_revoked(delegation);
+ nfs_mark_delegation_revoked(NFS_SERVER(inode), delegation);
ret = true;
out:
rcu_read_unlock();
@@ -1050,7 +1053,7 @@ void nfs_delegation_mark_returned(struct inode *inode,
delegation->stateid.seqid = stateid->seqid;
}
- nfs_mark_delegation_revoked(delegation);
+ nfs_mark_delegation_revoked(NFS_SERVER(inode), delegation);
clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
spin_unlock(&delegation->lock);
if (nfs_detach_delegation(NFS_I(inode), delegation, NFS_SERVER(inode)))
@@ -1270,7 +1273,7 @@ static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
if (delegation != NULL) {
if (nfs_detach_delegation(NFS_I(inode), delegation,
server) != NULL)
- nfs_free_delegation(delegation);
+ nfs_free_delegation(server, delegation);
/* Match nfs_start_delegation_return_locked */
nfs_put_delegation(delegation);
}
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index d2d36711a119..a9b44f12623f 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -254,6 +254,7 @@ struct nfs_server {
struct list_head state_owners_lru;
struct list_head layouts;
struct list_head delegations;
+ atomic_long_t nr_active_delegations;
struct list_head ss_copies;
struct list_head ss_src_copies;
--
2.47.2
next prev parent reply other threads:[~2025-07-18 8:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-18 8:14 use a hash for looking up delegation v3 Christoph Hellwig
2025-07-18 8:14 ` [PATCH 1/5] NFS: cleanup error handling in nfs4_server_common_setup Christoph Hellwig
2025-07-18 8:14 ` [PATCH 2/5] NFS: cleanup nfs_inode_reclaim_delegation Christoph Hellwig
2025-07-18 8:14 ` [PATCH 3/5] NFS: move the delegation_watermark module parameter Christoph Hellwig
2025-07-18 8:14 ` Christoph Hellwig [this message]
2025-07-18 8:14 ` [PATCH 5/5] NFS: use a hash table for delegation lookup Christoph Hellwig
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