From 82edffead58642796f085e9cd4c01a687883942c Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 20 Nov 2019 12:00:59 -0500 Subject: [PATCH] ceph: show tasks waiting on caps in debugfs caps file [ Upstream commit 3a3430affce5de301fc8e6e50fa3543d7597820e ] Add some visibility of tasks that are waiting for caps to the "caps" debugfs file. Display the tgid of the waiting task, inode number, and the caps the task needs and wants. Signed-off-by: Jeff Layton Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov Stable-dep-of: e7e607bd0048 ("ceph: defer stopping mdsc delayed_work") Signed-off-by: Sasha Levin --- fs/ceph/caps.c | 17 +++++++++++++++++ fs/ceph/debugfs.c | 13 +++++++++++++ fs/ceph/mds_client.c | 1 + fs/ceph/mds_client.h | 9 +++++++++ 4 files changed, 40 insertions(+) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 243e246cb504..4e88cb990723 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -2790,7 +2790,19 @@ int ceph_get_caps(struct file *filp, int need, int want, if (ret == -EAGAIN) continue; if (!ret) { + struct ceph_mds_client *mdsc = fsc->mdsc; + struct cap_wait cw; DEFINE_WAIT_FUNC(wait, woken_wake_function); + + cw.ino = inode->i_ino; + cw.tgid = current->tgid; + cw.need = need; + cw.want = want; + + spin_lock(&mdsc->caps_list_lock); + list_add(&cw.list, &mdsc->cap_wait_list); + spin_unlock(&mdsc->caps_list_lock); + add_wait_queue(&ci->i_cap_wq, &wait); flags |= NON_BLOCKING; @@ -2804,6 +2816,11 @@ int ceph_get_caps(struct file *filp, int need, int want, } remove_wait_queue(&ci->i_cap_wq, &wait); + + spin_lock(&mdsc->caps_list_lock); + list_del(&cw.list); + spin_unlock(&mdsc->caps_list_lock); + if (ret == -EAGAIN) continue; } diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c index facb387c2735..c281f32b54f7 100644 --- a/fs/ceph/debugfs.c +++ b/fs/ceph/debugfs.c @@ -139,6 +139,7 @@ static int caps_show(struct seq_file *s, void *p) struct ceph_fs_client *fsc = s->private; struct ceph_mds_client *mdsc = fsc->mdsc; int total, avail, used, reserved, min, i; + struct cap_wait *cw; ceph_reservation_status(fsc, &total, &avail, &used, &reserved, &min); seq_printf(s, "total\t\t%d\n" @@ -166,6 +167,18 @@ static int caps_show(struct seq_file *s, void *p) } mutex_unlock(&mdsc->mutex); + seq_printf(s, "\n\nWaiters:\n--------\n"); + seq_printf(s, "tgid ino need want\n"); + seq_printf(s, "-----------------------------------------------------\n"); + + spin_lock(&mdsc->caps_list_lock); + list_for_each_entry(cw, &mdsc->cap_wait_list, list) { + seq_printf(s, "%-13d0x%-17lx%-17s%-17s\n", cw->tgid, cw->ino, + ceph_cap_string(cw->need), + ceph_cap_string(cw->want)); + } + spin_unlock(&mdsc->caps_list_lock); + return 0; } diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 3bf81fe5f10a..6ceda2a4791c 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -4174,6 +4174,7 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work); mdsc->last_renew_caps = jiffies; 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->snap_flush_list); spin_lock_init(&mdsc->snap_flush_lock); diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h index 5cd131b41d84..14c7e8c49970 100644 --- a/fs/ceph/mds_client.h +++ b/fs/ceph/mds_client.h @@ -340,6 +340,14 @@ struct ceph_quotarealm_inode { struct inode *inode; }; +struct cap_wait { + struct list_head list; + unsigned long ino; + pid_t tgid; + int need; + int want; +}; + /* * mds client state */ @@ -416,6 +424,7 @@ struct ceph_mds_client { spinlock_t caps_list_lock; struct list_head caps_list; /* unused (reserved or unreserved) */ + struct list_head cap_wait_list; int caps_total_count; /* total caps allocated */ int caps_use_count; /* in use */ int caps_use_max; /* max used caps */