[3/3] ceph: add ceph_cap_unlink_work to fire check caps immediately

Commit Message

Xiubo Li Sept. 25, 2023, 5:28 a.m. UTC

From: Xiubo Li <[e-mail]>

When unlinking a file the check caps could be delayed for more than
5 seconds, but in MDS side it maybe waiting for the clients to
release caps.

This will add a dedicated work queue and list to help trigger to
fire the check caps and dirty buffer flushing immediately.

URL: https://tracker.ceph.com/issues/50223
Signed-off-by: Xiubo Li <[e-mail]>
---
 fs/ceph/caps.c       | 17 ++++++++++++++++-
 fs/ceph/mds_client.c | 34 ++++++++++++++++++++++++++++++++++
 fs/ceph/mds_client.h |  4 ++++
 3 files changed, 54 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 7ce275838007..a36366df7773 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -4793,7 +4793,22 @@  int ceph_drop_caps_for_unlink(struct inode *inode)
 		if (__ceph_caps_dirty(ci)) {
 			struct ceph_mds_client *mdsc =
 				ceph_inode_to_fs_client(inode)->mdsc;
-			__cap_delay_requeue_front(mdsc, ci);
+
+			doutc(mdsc->fsc->client, "%p %llx.%llx\n", inode,
+			      ceph_vinop(inode));
+			spin_lock(&mdsc->cap_unlink_delay_lock);
+			ci->i_ceph_flags |= CEPH_I_FLUSH;
+			if (!list_empty(&ci->i_cap_delay_list))
+				list_del_init(&ci->i_cap_delay_list);
+			list_add_tail(&ci->i_cap_delay_list,
+				      &mdsc->cap_unlink_delay_list);
+			spin_unlock(&mdsc->cap_unlink_delay_lock);
+
+			/*
+			 * Fire the work immediately, because the MDS maybe
+			 * waiting for caps release.
+			 */
+			schedule_work(&mdsc->cap_unlink_work);
 		}
 	}
 	spin_unlock(&ci->i_ceph_lock);
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 6fa7134beec8..a7bffb030036 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2500,6 +2500,37 @@  void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
 	}
 }
 
+static void ceph_cap_unlink_work(struct work_struct *work)
+{
+	struct ceph_mds_client *mdsc =
+		container_of(work, struct ceph_mds_client, cap_unlink_work);
+	struct ceph_client *cl = mdsc->fsc->client;
+
+	doutc(cl, "begin\n");
+	spin_lock(&mdsc->cap_unlink_delay_lock);
+	while (!list_empty(&mdsc->cap_unlink_delay_list)) {
+		struct ceph_inode_info *ci;
+		struct inode *inode;
+
+		ci = list_first_entry(&mdsc->cap_unlink_delay_list,
+				      struct ceph_inode_info,
+				      i_cap_delay_list);
+		list_del_init(&ci->i_cap_delay_list);
+
+		inode = igrab(&ci->netfs.inode);
+		if (inode) {
+			spin_unlock(&mdsc->cap_unlink_delay_lock);
+			doutc(cl, "on %p %llx.%llx\n", inode,
+			      ceph_vinop(inode));
+			ceph_check_caps(ci, CHECK_CAPS_FLUSH);
+			iput(inode);
+			spin_lock(&mdsc->cap_unlink_delay_lock);
+		}
+	}
+	spin_unlock(&mdsc->cap_unlink_delay_lock);
+	doutc(cl, "done\n");
+}
+
 /*
  * requests
  */
@@ -5372,6 +5403,8 @@  int ceph_mdsc_init(struct ceph_fs_client *fsc)
 	INIT_LIST_HEAD(&mdsc->cap_delay_list);
 	INIT_LIST_HEAD(&mdsc->cap_wait_list);
 	spin_lock_init(&mdsc->cap_delay_lock);
+	INIT_LIST_HEAD(&mdsc->cap_unlink_delay_list);
+	spin_lock_init(&mdsc->cap_unlink_delay_lock);
 	INIT_LIST_HEAD(&mdsc->snap_flush_list);
 	spin_lock_init(&mdsc->snap_flush_lock);
 	mdsc->last_cap_flush_tid = 1;
@@ -5380,6 +5413,7 @@  int ceph_mdsc_init(struct ceph_fs_client *fsc)
 	spin_lock_init(&mdsc->cap_dirty_lock);
 	init_waitqueue_head(&mdsc->cap_flushing_wq);
 	INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
+	INIT_WORK(&mdsc->cap_unlink_work, ceph_cap_unlink_work);
 	err = ceph_metric_init(&mdsc->metric);
 	if (err)
 		goto err_mdsmap;
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 2e6ddaa13d72..f25117fa910f 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -462,6 +462,8 @@  struct ceph_mds_client {
 	unsigned long    last_renew_caps;  /* last time we renewed our caps */
 	struct list_head cap_delay_list;   /* caps with delayed release */
 	spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
+	struct list_head cap_unlink_delay_list;  /* caps with delayed release for unlink */
+	spinlock_t       cap_unlink_delay_lock;  /* protects cap_unlink_delay_list */
 	struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 	spinlock_t       snap_flush_lock;
 
@@ -475,6 +477,8 @@  struct ceph_mds_client {
 	struct work_struct cap_reclaim_work;
 	atomic_t	   cap_reclaim_pending;
 
+	struct work_struct cap_unlink_work;
+
 	/*
 	 * Cap reservations
 	 *