On Mon, Nov 25, 2019 at 11:21 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> Display the tgid of the waiting task, plus inode number, and the
> caps we need and want.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> 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 f5a38910a82b..271d8283d263 100644
> --- a/fs/ceph/caps.c
> +++ b/fs/ceph/caps.c
> @@ -2764,7 +2764,19 @@ 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;
> @@ -2778,6 +2790,11 @@ 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 890f7f613390..40f9a640481d 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -4169,6 +4169,7 @@ 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 */
> --
> 2.23.0
>
Reviewed-by: "Yan, Zheng" <zyan@xxxxxxxxxx>
