This patch applyes the introduced pm_runtime_set_memalloc_noio on
block device so that PM core will teach mm to not allocate memory with
GFP_IOFS when calling the runtime_resume and runtime_suspend callback
for block devices and its ancestors.
Cc: Jens Axboe <ax...@kernel.dk>
Signed-off-by: Ming Lei <ming....@canonical.com>
--
v5:
- fix code style and one typo
v4:
- call pm_runtime_set_memalloc_noio(ddev, true) after device_add
---
block/genhd.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/block/genhd.c b/block/genhd.c
index 4125beb..2eb64a3 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -18,6 +18,7 @@
#include <linux/mutex.h>
#include <linux/idr.h>
#include <linux/log2.h>
+#include <linux/pm_runtime.h>
#include "blk.h"
@@ -534,6 +535,14 @@ static void register_disk(struct gendisk *disk)
return;
}
}
+
+ /*
+ * avoid probable deadlock caused by allocating memory with
+ * GFP_KERNEL in runtime_resume callback of its all ancestor
+ * devices
+ */
+ pm_runtime_set_memalloc_noio(ddev, true);
+
disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
@@ -663,6 +672,7 @@ void del_gendisk(struct gendisk *disk)
disk->driverfs_dev = NULL;
if (!sysfs_deprecated)
sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
+ pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
device_del(disk_to_dev(disk));
}
EXPORT_SYMBOL(del_gendisk);
--
1.7.9.5
--
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