libata: Use per port sync for detach

Commit 130f4caf14 ("libata: Ensure ata_port probe has completed before
detach") may cause system freeze during suspend.

Using async_synchronize_full() in PM callbacks is wrong, since async
callbacks that are already scheduled may wait for not-yet-scheduled
callbacks, causes a circular dependency.

Instead of using big hammer like async_synchronize_full(), use async
cookie to make sure port probe are synced, without affecting other
scheduled PM callbacks.

Fixes: 130f4caf14 ("libata: Ensure ata_port probe has completed before detach")
Suggested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: John Garry <john.garry@huawei.com>
BugLink: https://bugs.launchpad.net/bugs/1867983
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Kai-Heng Feng 2020-06-03 15:48:19 +08:00 коммит произвёл Jens Axboe
Родитель f650ef61e0
Коммит b5292111de
2 изменённых файлов: 8 добавлений и 6 удалений

Просмотреть файл

@ -42,7 +42,6 @@
#include <linux/workqueue.h>
#include <linux/scatterlist.h>
#include <linux/io.h>
#include <linux/async.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/glob.h>
@ -5778,7 +5777,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
/* perform each probe asynchronously */
for (i = 0; i < host->n_ports; i++) {
struct ata_port *ap = host->ports[i];
async_schedule(async_port_probe, ap);
ap->cookie = async_schedule(async_port_probe, ap);
}
return 0;
@ -5920,11 +5919,11 @@ void ata_host_detach(struct ata_host *host)
{
int i;
/* Ensure ata_port probe has completed */
async_synchronize_full();
for (i = 0; i < host->n_ports; i++)
for (i = 0; i < host->n_ports; i++) {
/* Ensure ata_port probe has completed */
async_synchronize_cookie(host->ports[i]->cookie + 1);
ata_port_detach(host->ports[i]);
}
/* the host is dead now, dissociate ACPI */
ata_acpi_dissociate(host);

Просмотреть файл

@ -22,6 +22,7 @@
#include <linux/acpi.h>
#include <linux/cdrom.h>
#include <linux/sched.h>
#include <linux/async.h>
/*
* Define if arch has non-standard setup. This is a _PCI_ standard
@ -872,6 +873,8 @@ struct ata_port {
struct timer_list fastdrain_timer;
unsigned long fastdrain_cnt;
async_cookie_t cookie;
int em_message_type;
void *private_data;