From 7b012732d005fba22912dda038dd253e3b9a1bfc Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Wed, 17 Apr 2024 15:13:22 -0400 Subject: [PATCH] dlm: fix sleep in atomic context This patch changes the orphans mutex to a spinlock since commit c288745f1d4a ("dlm: avoid blocking receive at the end of recovery") is using a rwlock_t to lock the DLM message receive path and do_purge() can be called while this lock is held that forbids to sleep. We need to use spin_lock_bh() because also a user context that calls dlm_user_purge() can call do_purge() and since commit 92d59adfaf71 ("dlm: do message processing in softirq context") the DLM message receive path is done under softirq context. Fixes: c288745f1d4a ("dlm: avoid blocking receive at the end of recovery") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/gfs2/9ad928eb-2ece-4ad9-a79c-d2bce228e4bc@moroto.mountain/ Signed-off-by: Alexander Aring Signed-off-by: David Teigland --- fs/dlm/dlm_internal.h | 2 +- fs/dlm/lock.c | 12 ++++++------ fs/dlm/lockspace.c | 2 +- 3 files changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h index 19e57cbd5b13..9085ba3b2f20 100644 --- a/fs/dlm/dlm_internal.h +++ b/fs/dlm/dlm_internal.h @@ -602,7 +602,7 @@ struct dlm_ls { spinlock_t ls_waiters_lock; struct list_head ls_waiters; /* lkbs needing a reply */ - struct mutex ls_orphans_mutex; + spinlock_t ls_orphans_lock; struct list_head ls_orphans; spinlock_t ls_new_rsb_spin; diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index bbbc9593a64e..f103b8c30592 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -5880,7 +5880,7 @@ int dlm_user_adopt_orphan(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, int found_other_mode = 0; int rv = 0; - mutex_lock(&ls->ls_orphans_mutex); + spin_lock_bh(&ls->ls_orphans_lock); list_for_each_entry(iter, &ls->ls_orphans, lkb_ownqueue) { if (iter->lkb_resource->res_length != namelen) continue; @@ -5897,7 +5897,7 @@ int dlm_user_adopt_orphan(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, *lkid = iter->lkb_id; break; } - mutex_unlock(&ls->ls_orphans_mutex); + spin_unlock_bh(&ls->ls_orphans_lock); if (!lkb && found_other_mode) { rv = -EAGAIN; @@ -6089,9 +6089,9 @@ static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) int error; hold_lkb(lkb); /* reference for the ls_orphans list */ - mutex_lock(&ls->ls_orphans_mutex); + spin_lock_bh(&ls->ls_orphans_lock); list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans); - mutex_unlock(&ls->ls_orphans_mutex); + spin_unlock_bh(&ls->ls_orphans_lock); set_unlock_args(0, lkb->lkb_ua, &args); @@ -6241,7 +6241,7 @@ static void do_purge(struct dlm_ls *ls, int nodeid, int pid) { struct dlm_lkb *lkb, *safe; - mutex_lock(&ls->ls_orphans_mutex); + spin_lock_bh(&ls->ls_orphans_lock); list_for_each_entry_safe(lkb, safe, &ls->ls_orphans, lkb_ownqueue) { if (pid && lkb->lkb_ownpid != pid) continue; @@ -6249,7 +6249,7 @@ static void do_purge(struct dlm_ls *ls, int nodeid, int pid) list_del_init(&lkb->lkb_ownqueue); dlm_put_lkb(lkb); } - mutex_unlock(&ls->ls_orphans_mutex); + spin_unlock_bh(&ls->ls_orphans_lock); } static int send_purge(struct dlm_ls *ls, int nodeid, int pid) diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index 5ce26882159e..ed23787271b1 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -436,7 +436,7 @@ static int new_lockspace(const char *name, const char *cluster, INIT_LIST_HEAD(&ls->ls_waiters); spin_lock_init(&ls->ls_waiters_lock); INIT_LIST_HEAD(&ls->ls_orphans); - mutex_init(&ls->ls_orphans_mutex); + spin_lock_init(&ls->ls_orphans_lock); INIT_LIST_HEAD(&ls->ls_new_rsb); spin_lock_init(&ls->ls_new_rsb_spin);