Hi Dan,
I am trying to track this patch and looking forward to get your comments.
Many thanks!
Ocean.
-----Original Message-----
From: oceanhehy(a)gmail.com <oceanhehy(a)gmail.com>
Sent: Tuesday, September 11, 2018 4:31 PM
To: dan.j.williams(a)intel.com; vishal.l.verma(a)intel.com; qi.fuli(a)jp.fujitsu.com;
linux-nvdimm(a)lists.01.org
Cc: Ocean HY1 He <hehy1(a)lenovo.com>
Subject: [External] [ndctl PATCH] ndctl: recover from failed namespace
creation
From: Ocean He <hehy1(a)lenovo.com>
When namespace creation failure occurs, the consumed namespace (seed or
0th
idle) and pfn/dax seed would block next namespace creation. A recovery is
needed to handle this type failure.
A symptom example (section size is 128MB) based on kernel 4.19-rc2 and
ndctl v62:
# ndctl create-namespace -r region1 -s 100m -t pmem -m fsdax
{
"dev":"namespace1.0",
"mode":"fsdax",
"map":"dev",
"size":"96.00 MiB (100.66 MB)",
"uuid":"ef9a0556-a610-40b5-8c71-43991765a2cc",
"raw_uuid":"177b22e2-b7e8-482f-a063-2b8de876d979",
"sector_size":512,
"blockdev":"pmem1",
"numa_node":1
}
# ndctl create-namespace -r region1 -s 100m -t pmem -m fsdax
libndctl: ndctl_pfn_enable: pfn1.1: failed to enable
Error: namespace1.1: failed to enable
failed to create namespace: No such device or address
# ndctl destroy-namespace namespace1.0 -f
destroyed 1 namespace
# ndctl create-namespace -r region1 -s 128m -t pmem -m fsdax
failed to create namespace: Device or resource busy
Signed-off-by: Ocean He <hehy1(a)lenovo.com>
---
Additional information:
A kernel patch to fix this has been reviewed by Dan Williams, and he prefers
to handle it in ndctl directly.
https://www.spinics.net/lists/kernel/msg2901465.html
ndctl/namespace.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/ndctl/namespace.c b/ndctl/namespace.c
index 510553c..76ee2ed 100644
--- a/ndctl/namespace.c
+++ b/ndctl/namespace.c
@@ -393,6 +393,8 @@ static int setup_namespace(struct ndctl_region
*region,
try(ndctl_pfn, set_align, pfn, p->align);
try(ndctl_pfn, set_namespace, pfn, ndns);
rc = ndctl_pfn_enable(pfn);
+ if (rc)
+ ndctl_pfn_set_namespace(pfn, NULL);
} else if (p->mode == NDCTL_NS_MODE_DAX) {
struct ndctl_dax *dax = ndctl_region_get_dax_seed(region);
@@ -402,6 +404,8 @@ static int setup_namespace(struct ndctl_region
*region,
try(ndctl_dax, set_align, dax, p->align);
try(ndctl_dax, set_namespace, dax, ndns);
rc = ndctl_dax_enable(dax);
+ if (rc)
+ ndctl_dax_set_namespace(dax, NULL);
} else if (p->mode == NDCTL_NS_MODE_SAFE) {
struct ndctl_btt *btt = ndctl_region_get_btt_seed(region);
@@ -783,7 +787,13 @@ static int namespace_create(struct ndctl_region
*region)
return -ENODEV;
}
- return setup_namespace(region, ndns, &p);
+ rc = setup_namespace(region, ndns, &p);
+ if (rc) {
+ ndctl_namespace_set_enforce_mode(ndns,
NDCTL_NS_MODE_RAW);
+ ndctl_namespace_delete(ndns);
+ }
+
+ return rc;
}
static int zero_info_block(struct ndctl_namespace *ndns)
--
1.8.3.1