md: mark some attributes as pre-alloc
Since __ATTR_PREALLOC was introduced in v3.19-rc1~78^2~18
it can now be used by md.
This ensure that writing to these sysfs attributes will never
block due to a memory allocation.
Such blocking could become a deadlock if mdmon is trying to
reconfigure an array after a failure prior to re-enabling writes.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c8d2bac..cadf9cc 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2555,7 +2555,7 @@
return err ? err : len;
}
static struct rdev_sysfs_entry rdev_state =
-__ATTR(state, S_IRUGO|S_IWUSR, state_show, state_store);
+__ATTR_PREALLOC(state, S_IRUGO|S_IWUSR, state_show, state_store);
static ssize_t
errors_show(struct md_rdev *rdev, char *page)
@@ -3638,7 +3638,8 @@
return err ?: len;
}
static struct md_sysfs_entry md_resync_start =
-__ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
+__ATTR_PREALLOC(resync_start, S_IRUGO|S_IWUSR,
+ resync_start_show, resync_start_store);
/*
* The array state can be:
@@ -3851,7 +3852,7 @@
return err ?: len;
}
static struct md_sysfs_entry md_array_state =
-__ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
+__ATTR_PREALLOC(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
static ssize_t
max_corrected_read_errors_show(struct mddev *mddev, char *page) {
@@ -4101,7 +4102,7 @@
}
static struct md_sysfs_entry md_metadata =
-__ATTR(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
+__ATTR_PREALLOC(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
static ssize_t
action_show(struct mddev *mddev, char *page)
@@ -4189,7 +4190,7 @@
}
static struct md_sysfs_entry md_scan_mode =
-__ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
+__ATTR_PREALLOC(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
static ssize_t
last_sync_action_show(struct mddev *mddev, char *page)
@@ -4335,7 +4336,8 @@
return sprintf(page, "%llu / %llu\n", resync, max_sectors);
}
-static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
+static struct md_sysfs_entry md_sync_completed =
+ __ATTR_PREALLOC(sync_completed, S_IRUGO, sync_completed_show, NULL);
static ssize_t
min_sync_show(struct mddev *mddev, char *page)
