[PATCH 5/5] x86/intel_rdt: Add diagnostics when making directories

From: Luck, Tony
Date: Mon Sep 18 2017 - 18:19:24 EST


From: Tony Luck <tony.luck@xxxxxxxxx>

Mostly this is about running out of RMIDs or CLOSIDs. Other
errors are various internal errors.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 8b851ae601df..dc8bc21cc6ee 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1574,8 +1574,10 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
int ret;

prdtgrp = rdtgroup_kn_lock_live(prgrp_kn);
+ seq_buf_clear(&last_cmd_status);
if (!prdtgrp) {
ret = -ENODEV;
+ seq_buf_puts(&last_cmd_status, "directory was removed\n");
goto out_unlock;
}

@@ -1583,6 +1585,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
if (!rdtgrp) {
ret = -ENOSPC;
+ seq_buf_puts(&last_cmd_status, "kernel out of memory\n");
goto out_unlock;
}
*r = rdtgrp;
@@ -1594,6 +1597,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
if (IS_ERR(kn)) {
ret = PTR_ERR(kn);
+ seq_buf_puts(&last_cmd_status, "kernfs create error\n");
goto out_free_rgrp;
}
rdtgrp->kn = kn;
@@ -1607,24 +1611,32 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
kernfs_get(kn);

ret = rdtgroup_kn_set_ugid(kn);
- if (ret)
+ if (ret) {
+ seq_buf_puts(&last_cmd_status, "kernfs perm error\n");
goto out_destroy;
+ }

files = RFTYPE_BASE | RFTYPE_CTRL;
files = RFTYPE_BASE | BIT(RF_CTRLSHIFT + rtype);
ret = rdtgroup_add_files(kn, files);
- if (ret)
+ if (ret) {
+ seq_buf_puts(&last_cmd_status, "kernfs fill error\n");
goto out_destroy;
+ }

if (rdt_mon_capable) {
ret = alloc_rmid();
- if (ret < 0)
+ if (ret < 0) {
+ seq_buf_puts(&last_cmd_status, "out of RMIDs\n");
goto out_destroy;
+ }
rdtgrp->mon.rmid = ret;

ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
- if (ret)
+ if (ret) {
+ seq_buf_puts(&last_cmd_status, "kernfs subdir error\n");
goto out_idfree;
+ }
}
kernfs_activate(kn);

@@ -1702,8 +1714,10 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,

kn = rdtgrp->kn;
ret = closid_alloc();
- if (ret < 0)
+ if (ret < 0) {
+ seq_buf_puts(&last_cmd_status, "out of CLOSIDs\n");
goto out_common_fail;
+ }
closid = ret;

rdtgrp->closid = closid;
@@ -1715,8 +1729,10 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
* of tasks and cpus to monitor.
*/
ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
- if (ret)
+ if (ret) {
+ seq_buf_puts(&last_cmd_status, "kernfs subdir error\n");
goto out_id_free;
+ }
}

goto out_unlock;
--
2.11.0