[PATCH 5.17 663/772] dlm: fix wake_up() calls for pending remove

From: Greg Kroah-Hartman
Date: Tue Jun 07 2022 - 17:42:13 EST


From: Alexander Aring <aahringo@xxxxxxxxxx>

commit f6f7418357457ed58cbb020fc97e74d4e0e7b47f upstream.

This patch move the wake_up() call at the point when a remove message
completed. Before it was only when a remove message was going to be
sent. The possible waiter in wait_pending_remove() waits until a remove
is done if the resource name matches with the per ls variable
ls->ls_remove_name. If this is the case we must wait until a pending
remove is done which is indicated if DLM_WAIT_PENDING_COND() returns
false which will always be the case when ls_remove_len and
ls_remove_name are unset to indicate that a remove is not going on
anymore.

Fixes: 21d9ac1a5376 ("fs: dlm: use event based wait for pending remove")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
Signed-off-by: David Teigland <teigland@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/dlm/lock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -1795,7 +1795,6 @@ static void shrink_bucket(struct dlm_ls
memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
spin_unlock(&ls->ls_remove_spin);
spin_unlock(&ls->ls_rsbtbl[b].lock);
- wake_up(&ls->ls_remove_wait);

send_remove(r);

@@ -1804,6 +1803,7 @@ static void shrink_bucket(struct dlm_ls
ls->ls_remove_len = 0;
memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
spin_unlock(&ls->ls_remove_spin);
+ wake_up(&ls->ls_remove_wait);

dlm_free_rsb(r);
}
@@ -4079,7 +4079,6 @@ static void send_repeat_remove(struct dl
memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
spin_unlock(&ls->ls_remove_spin);
spin_unlock(&ls->ls_rsbtbl[b].lock);
- wake_up(&ls->ls_remove_wait);

rv = _create_message(ls, sizeof(struct dlm_message) + len,
dir_nodeid, DLM_MSG_REMOVE, &ms, &mh);
@@ -4095,6 +4094,7 @@ static void send_repeat_remove(struct dl
ls->ls_remove_len = 0;
memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
spin_unlock(&ls->ls_remove_spin);
+ wake_up(&ls->ls_remove_wait);
}

static int receive_request(struct dlm_ls *ls, struct dlm_message *ms)