md: use sysfs_notify_dirent to notify changes to md/dev-xxx/state
The 'state' file for a device reports, for example, when the device
has failed. Changes should be reported to userspace ASAP without
the possibility of blocking on low-memory. sysfs_notify does
have that possibility (as it takes a mutex which can be held
across a kmalloc) so use sysfs_notify_dirent instead.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index feea72d..8b30347 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1462,6 +1462,8 @@
kobject_del(&rdev->kobj);
goto fail;
}
+ rdev->sysfs_state = sysfs_get_dirent(rdev->kobj.sd, "state");
+
list_add_rcu(&rdev->same_set, &mddev->disks);
bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
return 0;
@@ -1491,7 +1493,8 @@
printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
rdev->mddev = NULL;
sysfs_remove_link(&rdev->kobj, "block");
-
+ sysfs_put(rdev->sysfs_state);
+ rdev->sysfs_state = NULL;
/* We need to delay this, otherwise we can deadlock when
* writing to 'remove' to "dev/state". We also need
* to delay it due to rcu usage.
@@ -1926,8 +1929,8 @@
err = 0;
}
- if (!err)
- sysfs_notify(&rdev->kobj, NULL, "state");
+ if (!err && rdev->sysfs_state)
+ sysfs_notify_dirent(rdev->sysfs_state);
return err ? err : len;
}
static struct rdev_sysfs_entry rdev_state =
@@ -2022,7 +2025,7 @@
rdev->raid_disk = -1;
return err;
} else
- sysfs_notify(&rdev->kobj, NULL, "state");
+ sysfs_notify_dirent(rdev->sysfs_state);
sprintf(nm, "rd%d", rdev->raid_disk);
if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
printk(KERN_WARNING
@@ -2039,7 +2042,7 @@
clear_bit(Faulty, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
set_bit(In_sync, &rdev->flags);
- sysfs_notify(&rdev->kobj, NULL, "state");
+ sysfs_notify_dirent(rdev->sysfs_state);
}
return len;
}
@@ -3583,7 +3586,7 @@
return -EINVAL;
}
}
- sysfs_notify(&rdev->kobj, NULL, "state");
+ sysfs_notify_dirent(rdev->sysfs_state);
}
md_probe(mddev->unit, NULL, NULL);
@@ -4302,7 +4305,7 @@
if (err)
export_rdev(rdev);
else
- sysfs_notify(&rdev->kobj, NULL, "state");
+ sysfs_notify_dirent(rdev->sysfs_state);
md_update_sb(mddev, 1);
if (mddev->degraded)
@@ -6113,7 +6116,7 @@
rdev_for_each(rdev, rtmp, mddev)
if (test_and_clear_bit(StateChanged, &rdev->flags))
- sysfs_notify(&rdev->kobj, NULL, "state");
+ sysfs_notify_dirent(rdev->sysfs_state);
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
@@ -6223,7 +6226,7 @@
void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
{
- sysfs_notify(&rdev->kobj, NULL, "state");
+ sysfs_notify_dirent(rdev->sysfs_state);
wait_event_timeout(rdev->blocked_wait,
!test_bit(Blocked, &rdev->flags),
msecs_to_jiffies(5000));