Re: [ndctl PATCH 3/3] ndctl/namespace: add a --continue option to create namespaces greedily

[jane . chu]

Hi, Vishal,


On 8/28/19 5:17 PM, Vishal Verma wrote:

Add a --continue option to ndctl-create-namespaces to allow the creation
of as many namespaces as possible, that meet the given filter
restrictions.

The creation loop will be aborted if a failure is encountered at any
point.

Just wondering what is the motivation behind providing this option?

thanks!
-jane

Link: https://github.com/pmem/ndctl/issues/106
Reported-by: Steve Scargal <steve.scarg...@intel.com>
Cc: Jeff Moyer <jmo...@redhat.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Vishal Verma <vishal.l.ve...@intel.com>
---
  .../ndctl/ndctl-create-namespace.txt          |  7 ++++++
  ndctl/namespace.c                             | 25 +++++++++++++++----
  2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/Documentation/ndctl/ndctl-create-namespace.txt 
b/Documentation/ndctl/ndctl-create-namespace.txt
index c9ae27c..55a8581 100644
--- a/Documentation/ndctl/ndctl-create-namespace.txt
+++ b/Documentation/ndctl/ndctl-create-namespace.txt
@@ -215,6 +215,13 @@ include::xable-region-options.txt[]
  --bus=::
  include::xable-bus-options.txt[]

+-c::

+--continue::
+       Do not stop after creating one namespace. Instead, greedily create as
+       many namespaces as possible within the given --bus and --region filter
+       restrictions. This will abort if any creation attempt results in an
+       error.
+
  include::../copyright.txt[]

SEE ALSO

diff --git a/ndctl/namespace.c b/ndctl/namespace.c
index af20a42..8d6b249 100644
--- a/ndctl/namespace.c
+++ b/ndctl/namespace.c
@@ -41,6 +41,7 @@ static struct parameters {
        bool do_scan;
        bool mode_default;
        bool autolabel;
+       bool greedy;
        const char *bus;
        const char *map;
        const char *type;
@@ -114,7 +115,9 @@ OPT_STRING('t', "type", &param.type, "type", \
  OPT_STRING('a', "align", &param.align, "align", \
        "specify the namespace alignment in bytes (default: 2M)"), \
  OPT_BOOLEAN('f', "force", &force, "reconfigure namespace even if currently 
active"), \
-OPT_BOOLEAN('L', "autolabel", &param.autolabel, "automatically initialize 
labels")
+OPT_BOOLEAN('L', "autolabel", &param.autolabel, "automatically initialize 
labels"), \
+OPT_BOOLEAN('c', "continue", &param.greedy, \
+       "continue creating namespaces as long as the filter criteria are met")

#define CHECK_OPTIONS() \

  OPT_BOOLEAN('R', "repair", &repair, "perform metadata repairs"), \
@@ -1365,8 +1368,11 @@ static int do_xaction_namespace(const char *namespace,
                                rc = namespace_create(region);
                                if (rc == -EAGAIN)
                                        continue;
-                               if (rc == 0)
-                                       *processed = 1;
+                               if (rc == 0) {
+                                       (*processed)++;
+                                       if (param.greedy)
+                                               continue;
+                               }
                                return rc;
                        }
                        ndctl_namespace_foreach_safe(region, ndns, _n) {
@@ -1427,9 +1433,15 @@ static int do_xaction_namespace(const char *namespace,
                /*
                 * Namespace creation searched through all candidate
                 * regions and all of them said "nope, I don't have
-                * enough capacity", so report -ENOSPC
+                * enough capacity", so report -ENOSPC. Except during
+                * greedy namespace creation using --continue as we
+                * may have created some namespaces already, and the
+                * last one in the region search may preexist.
                 */
-               rc = -ENOSPC;
+               if (param.greedy && (*processed) > 0)
+                       rc = 0;
+               else
+                       rc = -ENOSPC;
        }

return rc;

@@ -1487,6 +1499,9 @@ int cmd_create_namespace(int argc, const char **argv, 
struct ndctl_ctx *ctx)
                rc = do_xaction_namespace(NULL, ACTION_CREATE, ctx, &created);
        }

+ if (param.greedy)

+               fprintf(stderr, "created %d namespace%s\n", created,
+                       created == 1 ? "" : "s");
        if (rc < 0 || (!namespace && created < 1)) {
                fprintf(stderr, "failed to %s namespace: %s\n", namespace
                                ? "reconfigure" : "create", strerror(-rc));

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm