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authorVasant Hegde <hegdevasant@linux.vnet.ibm.com>2020-10-17 18:42:36 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2020-10-19 13:58:52 +0200
commit358ab796ce78ba271a6ff82834183ffb2cb68c4c (patch)
treeca31d08756cbeee6fb850bdc0c97a5b6c6c108e5
parentpowerpc/powernv/dump: Fix race while processing OPAL dump (diff)
downloadlinux-358ab796ce78ba271a6ff82834183ffb2cb68c4c.tar.xz
linux-358ab796ce78ba271a6ff82834183ffb2cb68c4c.zip
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 <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201017164236.264713-1-hegdevasant@linux.vnet.ibm.com
-rw-r--r--arch/powerpc/platforms/powernv/opal-dump.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-dump.c b/arch/powerpc/platforms/powernv/opal-dump.c
index 0e6693bacb7e..00c5a59d82d9 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;
}