From: Vasant Hegde Date: Sat, 17 Oct 2020 16:42:36 +0000 (+0530) Subject: powerpc/powernv/dump: Handle multiple writes to ack attribute X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=358ab796ce78ba271a6ff82834183ffb2cb68c4c;p=linux.git powerpc/powernv/dump: Handle multiple writes to ack attribute Even though we use self removing sysfs helper, we still need to make sure we do the final kobject delete conditionally. sysfs_remove_file_self() will handle parallel calls to remove the sysfs attribute file and returns true only in the caller that removed the attribute file. The other parallel callers are returned false. Do the final kobject delete checking the return value of sysfs_remove_file_self(). Signed-off-by: Vasant Hegde Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201017164236.264713-1-hegdevasant@linux.vnet.ibm.com --- diff --git a/arch/powerpc/platforms/powernv/opal-dump.c b/arch/powerpc/platforms/powernv/opal-dump.c index 0e6693bacb7e7..00c5a59d82d93 100644 --- a/arch/powerpc/platforms/powernv/opal-dump.c +++ b/arch/powerpc/platforms/powernv/opal-dump.c @@ -88,9 +88,14 @@ static ssize_t dump_ack_store(struct dump_obj *dump_obj, const char *buf, size_t count) { - dump_send_ack(dump_obj->id); - sysfs_remove_file_self(&dump_obj->kobj, &attr->attr); - kobject_put(&dump_obj->kobj); + /* + * Try to self remove this attribute. If we are successful, + * delete the kobject itself. + */ + if (sysfs_remove_file_self(&dump_obj->kobj, &attr->attr)) { + dump_send_ack(dump_obj->id); + kobject_put(&dump_obj->kobj); + } return count; }