From 991834f5dcff9d515fce3b74a83a40ffc626e012 Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Tue, 25 Jul 2023 12:08:36 -0400
Subject: [PATCH] Remove zl_issuer_lock from zil_suspend().
This locking was recently added as part of #14979. But appears it
is illegal to take zl_issuer_lock while holding dp_config_rwlock,
taken by dsl_pool_hold(). It causes deadlock with sync thread in
spa_sync_upgrades(). On a second thought, we should not
need this locking, since zil_commit_impl() we call below takes
zl_issuer_lock, that should sufficiently protect zl_suspend reads,
combined with other logic from #14979.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #15103
---
module/zfs/zil.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/module/zfs/zil.c b/module/zfs/zil.c
index af7137faac..be5b9edf6e 100644
--- a/module/zfs/zil.c
+++ b/module/zfs/zil.c
@@ -3941,13 +3941,11 @@ zil_suspend(const char *osname, void **cookiep)
return (error);
zilog = dmu_objset_zil(os);
- mutex_enter(&zilog->zl_issuer_lock);
mutex_enter(&zilog->zl_lock);
zh = zilog->zl_header;
if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */
mutex_exit(&zilog->zl_lock);
- mutex_exit(&zilog->zl_issuer_lock);
dmu_objset_rele(os, suspend_tag);
return (SET_ERROR(EBUSY));
}
@@ -3961,7 +3959,6 @@ zil_suspend(const char *osname, void **cookiep)
if (cookiep == NULL && !zilog->zl_suspending &&
(zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) {
mutex_exit(&zilog->zl_lock);
- mutex_exit(&zilog->zl_issuer_lock);
dmu_objset_rele(os, suspend_tag);
return (0);
}
@@ -3970,7 +3967,6 @@ zil_suspend(const char *osname, void **cookiep)
dsl_pool_rele(dmu_objset_pool(os), suspend_tag);
zilog->zl_suspend++;
- mutex_exit(&zilog->zl_issuer_lock);
if (zilog->zl_suspend > 1) {
/*