From: Jeff Layton jlayton@kernel.org
[ 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 jlayton@kernel.org Reviewed-by: "Yan, Zheng" zyan@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Stable-dep-of: e7e607bd0048 ("ceph: defer stopping mdsc delayed_work") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 243e246cb5046..4e88cb9907230 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 facb387c27356..c281f32b54f7b 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 3bf81fe5f10a3..6ceda2a4791c4 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 5cd131b41d84f..14c7e8c49970a 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 */