diff --git a/module/os/linux/zfs/zfs_ctldir.c b/module/os/linux/zfs/zfs_ctldir.c index d33188f382..c58d851d77 100644 --- a/module/os/linux/zfs/zfs_ctldir.c +++ b/module/os/linux/zfs/zfs_ctldir.c @@ -118,6 +118,7 @@ typedef struct { spa_t *se_spa; /* pool spa */ uint64_t se_objsetid; /* snapshot objset id */ struct dentry *se_root_dentry; /* snapshot root dentry */ + krwlock_t se_taskqid_lock; /* scheduled unmount taskqid lock */ taskqid_t se_taskqid; /* scheduled unmount taskqid */ avl_node_t se_node_name; /* zfs_snapshots_by_name link */ avl_node_t se_node_objsetid; /* zfs_snapshots_by_objsetid link */ @@ -144,6 +145,7 @@ zfsctl_snapshot_alloc(const char *full_name, const char *full_path, spa_t *spa, se->se_objsetid = objsetid; se->se_root_dentry = root_dentry; se->se_taskqid = TASKQID_INVALID; + rw_init(&se->se_taskqid_lock, NULL, RW_DEFAULT, NULL); zfs_refcount_create(&se->se_refcount); @@ -160,6 +162,7 @@ zfsctl_snapshot_free(zfs_snapentry_t *se) zfs_refcount_destroy(&se->se_refcount); kmem_strfree(se->se_name); kmem_strfree(se->se_path); + rw_destroy(se->se_taskqid_lock); kmem_free(se, sizeof (zfs_snapentry_t)); } @@ -335,7 +338,9 @@ snapentry_expire(void *data) return; } + rw_enter(&se->se_taskqid_lock, RW_WRITER); se->se_taskqid = TASKQID_INVALID; + rw_exit(&se->se_taskqid_lock); (void) zfsctl_snapshot_unmount(se->se_name, MNT_EXPIRE); zfsctl_snapshot_rele(se); @@ -359,8 +364,18 @@ snapentry_expire(void *data) static void zfsctl_snapshot_unmount_cancel(zfs_snapentry_t *se) { - if (taskq_cancel_id(system_delay_taskq, se->se_taskqid) == 0) { - se->se_taskqid = TASKQID_INVALID; + int err = 0; + rw_enter(&se->se_taskqid_lock, RW_WRITER); + err = taskq_cancel_id(system_delay_taskq, se->se_taskqid); + /* + * if we get ENOENT, the taskq couldn't be found to be + * canceled, so we can just mark it as invalid because + * it's already gone. If we got EBUSY, then we already + * blocked until it was gone _anyway_, so we don't care. + */ + se->se_taskqid = TASKQID_INVALID; + rw_exit(&se->se_taskqid_lock); + if (err == 0) { zfsctl_snapshot_rele(se); } } @@ -371,14 +386,16 @@ zfsctl_snapshot_unmount_cancel(zfs_snapentry_t *se) static void zfsctl_snapshot_unmount_delay_impl(zfs_snapentry_t *se, int delay) { - ASSERT3S(se->se_taskqid, ==, TASKQID_INVALID); if (delay <= 0) return; zfsctl_snapshot_hold(se); + rw_enter(&se->se_taskqid_lock, RW_WRITER); + ASSERT3S(se->se_taskqid, ==, TASKQID_INVALID); se->se_taskqid = taskq_dispatch_delay(system_delay_taskq, snapentry_expire, se, TQ_SLEEP, ddi_get_lbolt() + delay * HZ); + rw_exit(&se->se_taskqid_lock); } /*