From: Aaron Tomlin Date: Wed, 25 Mar 2026 00:11:58 +0000 (-0400) Subject: fs/resctrl: Report invalid domain ID when parsing io_alloc_cbm X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d06b8e7c97c3290e61006e30b32beb9e715fab82;p=thirdparty%2Fkernel%2Flinux.git fs/resctrl: Report invalid domain ID when parsing io_alloc_cbm The last_cmd_status file is intended to report details about the most recent resctrl filesystem operation, specifically to aid in diagnosing failures. However, when parsing io_alloc_cbm, if a user provides a domain ID that does not exist in the resource, the operation fails with -EINVAL without updating last_cmd_status. This results in inconsistent behaviour where the system call returns an error, but last_cmd_status misleadingly reports "ok", leaving the user unaware that the failure was caused by an invalid domain ID. Write an error message to last_cmd_status when the target domain ID cannot be found. Fixes: 28fa2cce7a83 ("fs/resctrl: Introduce interface to modify io_alloc capacity bitmasks") Suggested-by: Reinette Chatre Signed-off-by: Aaron Tomlin Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Babu Moger Tested-by: Babu Moger Link: https://patch.msgid.link/20260325001159.447075-2-atomlin@atomlin.com --- diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index cc4237c57cbe4..2ef53161ce119 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -992,6 +992,7 @@ next: } } + rdt_last_cmd_printf("Invalid domain %lu\n", dom_id); return -EINVAL; }