From: Aneesh Kumar K.V Date: Wed, 14 Oct 2020 06:48:13 +0000 (+0530) Subject: powerpc/opal_elog: Handle multiple writes to ack attribute X-Git-Tag: howlett/maple_spf/20210104~708^2~11 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=d4263b12a1a0e8816e021450be0765a1ad8bb53c;p=users%2Fjedix%2Flinux-maple.git powerpc/opal_elog: 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: Aneesh Kumar K.V Reviewed-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201014064813.109515-1-aneesh.kumar@linux.ibm.com --- diff --git a/arch/powerpc/platforms/powernv/opal-elog.c b/arch/powerpc/platforms/powernv/opal-elog.c index 5e33b1fc67c2b..37b380eef41a4 100644 --- a/arch/powerpc/platforms/powernv/opal-elog.c +++ b/arch/powerpc/platforms/powernv/opal-elog.c @@ -72,9 +72,14 @@ static ssize_t elog_ack_store(struct elog_obj *elog_obj, const char *buf, size_t count) { - opal_send_ack_elog(elog_obj->id); - sysfs_remove_file_self(&elog_obj->kobj, &attr->attr); - kobject_put(&elog_obj->kobj); + /* + * Try to self remove this attribute. If we are successful, + * delete the kobject itself. + */ + if (sysfs_remove_file_self(&elog_obj->kobj, &attr->attr)) { + opal_send_ack_elog(elog_obj->id); + kobject_put(&elog_obj->kobj); + } return count; }