Re: [ndctl PATCHv4] ndctl: Use max_available_extent for namespace

[Masayoshi Mizuma <msys.mizuma@gmail.com>]

Hi Keith,

I tested your patch with the following test script.
The result is good to me. 

Please feel free to add:

   Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>

Test script:
---
#!/bin/bash -Ex

NDCTL=./ndctl/ndctl

modprobe nfit_test
region=$($NDCTL list -b nfit_test.0 -R -t pmem | jq -r .[].dev | head -1)

available_sz=$($NDCTL list -r $region | jq -r .[].available_size)
size=$(( available_sz/4 ))

NS1=$($NDCTL create-namespace -r $region -t pmem -s $size | jq -r .dev)
NS2=$($NDCTL create-namespace -r $region -t pmem -s $size | jq -r .dev)
NS3=$($NDCTL create-namespace -r $region -t pmem -s $size | jq -r .dev)

$NDCTL disable-namespace $NS2
$NDCTL destroy-namespace $NS2

$NDCTL list -r $region

$NDCTL create-namespace -r $region -t pmem 
ret=$?

$NDCTL disable-region all
modprobe -r nfit_test

exit $ret
---

Thanks,
Masa

On 07/24/2018 06:31 PM, Keith Busch wrote:
> The available_size attribute returns all the unused regions, but a
> memory namespace has to use contiguous free regions. This patch uses the
> max_available_extent attribute, which reports the largest capacity that
> can be created when determining what size to allocate.
> 
> If the attribute is available, this patch will also report the max
> available extent in the region list output.
> 
> Signed-off-by: Keith Busch <keith.busch@intel.com>
> ---
> v3 -> v4:
> 
>   Moved the symbol to the appropriate version section of the symbols
>   script.
> 
>   Report the max available extent in the region list if the attribute
>   exists.
> 
>  ndctl/lib/libndctl.c   | 33 +++++++++++++++++++++++++++++++++
>  ndctl/lib/libndctl.sym |  1 +
>  ndctl/libndctl.h       |  2 ++
>  ndctl/list.c           |  9 +++++++++
>  ndctl/namespace.c      |  4 +++-
>  5 files changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c
> index 969e4aa..e911ea2 100644
> --- a/ndctl/lib/libndctl.c
> +++ b/ndctl/lib/libndctl.c
> @@ -2107,6 +2107,39 @@ NDCTL_EXPORT unsigned long long ndctl_region_get_available_size(
>  	return strtoull(buf, NULL, 0);
>  }
>  
> +NDCTL_EXPORT unsigned long long ndctl_region_get_max_available_extent(
> +		struct ndctl_region *region)
> +{
> +	unsigned int nstype = ndctl_region_get_nstype(region);
> +	struct ndctl_ctx *ctx = ndctl_region_get_ctx(region);
> +	char *path = region->region_buf;
> +	int len = region->buf_len;
> +	char buf[SYSFS_ATTR_SIZE];
> +
> +	switch (nstype) {
> +	case ND_DEVICE_NAMESPACE_PMEM:
> +	case ND_DEVICE_NAMESPACE_BLK:
> +		break;
> +	default:
> +		return 0;
> +	}
> +
> +	if (snprintf(path, len,
> +		     "%s/max_available_extent", region->region_path) >= len) {
> +		err(ctx, "%s: buffer too small!\n",
> +				ndctl_region_get_devname(region));
> +		return ULLONG_MAX;
> +	}
> +
> +	/* fall back to legacy behavior if max extents is not exported */
> +	if (sysfs_read_attr(ctx, path, buf) < 0) {
> +		dbg(ctx, "max extents attribute not exported on older kernels\n");
> +		return ULLONG_MAX;
> +	}
> +
> +	return strtoull(buf, NULL, 0);
> +}
> +
>  NDCTL_EXPORT unsigned int ndctl_region_get_range_index(struct ndctl_region *region)
>  {
>  	return region->range_index;
> diff --git a/ndctl/lib/libndctl.sym b/ndctl/lib/libndctl.sym
> index 9b36960..2bc312d 100644
> --- a/ndctl/lib/libndctl.sym
> +++ b/ndctl/lib/libndctl.sym
> @@ -375,4 +375,5 @@ global:
>  	ndctl_dimm_get_flags;
>  	ndctl_dimm_get_event_flags;
>  	ndctl_dimm_is_flag_supported;
> +	ndctl_region_get_max_available_extent;
>  } LIBNDCTL_16;
> diff --git a/ndctl/libndctl.h b/ndctl/libndctl.h
> index 6a6bb0d..a146502 100644
> --- a/ndctl/libndctl.h
> +++ b/ndctl/libndctl.h
> @@ -350,6 +350,8 @@ unsigned int ndctl_region_get_interleave_ways(struct ndctl_region *region);
>  unsigned int ndctl_region_get_mappings(struct ndctl_region *region);
>  unsigned long long ndctl_region_get_size(struct ndctl_region *region);
>  unsigned long long ndctl_region_get_available_size(struct ndctl_region *region);
> +unsigned long long ndctl_region_get_max_available_extent(
> +		struct ndctl_region *region);
>  unsigned int ndctl_region_get_range_index(struct ndctl_region *region);
>  unsigned int ndctl_region_get_type(struct ndctl_region *region);
>  struct ndctl_namespace *ndctl_region_get_namespace_seed(
> diff --git a/ndctl/list.c b/ndctl/list.c
> index a06edc9..82e88bb 100644
> --- a/ndctl/list.c
> +++ b/ndctl/list.c
> @@ -72,6 +72,7 @@ static struct json_object *region_to_json(struct ndctl_region *region,
>  	struct ndctl_interleave_set *iset;
>  	struct ndctl_mapping *mapping;
>  	unsigned int bb_count = 0;
> +	unsigned long long extent;
>  	enum ndctl_persistence_domain pd;
>  	int numa;
>  
> @@ -94,6 +95,14 @@ static struct json_object *region_to_json(struct ndctl_region *region,
>  		goto err;
>  	json_object_object_add(jregion, "available_size", jobj);
>  
> +	extent = ndctl_region_get_max_available_extent(region);
> +	if (extent != ULLONG_MAX) {
> +		jobj = util_json_object_size(extent, flags);
> +		if (!jobj)
> +			goto err;
> +		json_object_object_add(jregion, "max_available_extent", jobj);
> +	}
> +
>  	switch (ndctl_region_get_type(region)) {
>  	case ND_DEVICE_REGION_PMEM:
>  		jobj = json_object_new_string("pmem");
> diff --git a/ndctl/namespace.c b/ndctl/namespace.c
> index fe86d82..cfe0559 100644
> --- a/ndctl/namespace.c
> +++ b/ndctl/namespace.c
> @@ -764,7 +764,9 @@ static int namespace_create(struct ndctl_region *region)
>  		return -EAGAIN;
>  	}
>  
> -	available = ndctl_region_get_available_size(region);
> +	available = ndctl_region_get_max_available_extent(region);
> +	if (available == ULLONG_MAX)
> +		available = ndctl_region_get_available_size(region);
>  	if (!available || p.size > available) {
>  		debug("%s: insufficient capacity size: %llx avail: %llx\n",
>  			devname, p.size, available);
> 
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm