[PATCH ndctl v2 4/7] cxl/region: accept user-supplied UUIDs for pmem regions

[Vishal Verma]

Attempting to add additional checking around user-supplied UUIDs against
'ram' type regions revealed that commit 21b089025178 ("cxl: add a 
'create-region' command")
completely neglected to add the requisite support for accepting
user-supplied UUIDs, even though the man page for cxl-create-region
advertised the option.

Fix this by actually adding this option now, and add checks to validate
the user-supplied UUID, and refuse it for ram regions.

Cc: Dan Williams <dan.j.willi...@intel.com>
Reviewed-by: Dan Williams <dan.j.willi...@intel.com>
Reviewed-by: Ira Weiny <ira.we...@intel.com>
Signed-off-by: Vishal Verma <vishal.l.ve...@intel.com>
---
 cxl/region.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/cxl/region.c b/cxl/region.c
index c69cb9a..5c908bb 100644
--- a/cxl/region.c
+++ b/cxl/region.c
@@ -22,6 +22,7 @@ static struct region_params {
        const char *bus;
        const char *size;
        const char *type;
+       const char *uuid;
        const char *root_decoder;
        const char *region;
        int ways;
@@ -40,6 +41,7 @@ struct parsed_params {
        u64 ep_min_size;
        int ways;
        int granularity;
+       uuid_t uuid;
        struct json_object *memdevs;
        int num_memdevs;
        int argc;
@@ -74,6 +76,8 @@ OPT_INTEGER('g', "granularity", &param.granularity,  \
            "granularity of the interleave set"), \
 OPT_STRING('t', "type", &param.type, \
           "region type", "region type - 'pmem' or 'ram'"), \
+OPT_STRING('U', "uuid", &param.uuid, \
+          "region uuid", "uuid for the new region (default: autogenerate)"), \
 OPT_BOOLEAN('m', "memdevs", &param.memdevs, \
            "non-option arguments are memdevs"), \
 OPT_BOOLEAN('u', "human", &param.human, "use human friendly number formats")
@@ -293,6 +297,11 @@ static int parse_create_options(struct cxl_ctx *ctx, int 
count,
 
        if (param.type) {
                p->mode = cxl_decoder_mode_from_ident(param.type);
+               if (p->mode == CXL_DECODER_MODE_RAM && param.uuid) {
+                       log_err(&rl,
+                               "can't set UUID for ram / volatile regions");
+                       return -EINVAL;
+               }
                if (p->mode == CXL_DECODER_MODE_NONE) {
                        log_err(&rl, "unsupported type: %s\n", param.type);
                        return -EINVAL;
@@ -341,6 +350,13 @@ static int parse_create_options(struct cxl_ctx *ctx, int 
count,
                }
        }
 
+       if (param.uuid) {
+               if (uuid_parse(param.uuid, p->uuid)) {
+                       error("failed to parse uuid: '%s'\n", param.uuid);
+                       return -EINVAL;
+               }
+       }
+
        return 0;
 }
 
@@ -562,7 +578,6 @@ static int create_region(struct cxl_ctx *ctx, int *count,
        int i, rc, granularity;
        u64 size, max_extent;
        const char *devname;
-       uuid_t uuid;
 
        rc = create_region_validate_config(ctx, p);
        if (rc)
@@ -623,8 +638,9 @@ static int create_region(struct cxl_ctx *ctx, int *count,
        try(cxl_region, set_interleave_granularity, region, granularity);
        try(cxl_region, set_interleave_ways, region, p->ways);
        if (p->mode == CXL_DECODER_MODE_PMEM) {
-               uuid_generate(uuid);
-               try(cxl_region, set_uuid, region, uuid);
+               if (!param.uuid)
+                       uuid_generate(p->uuid);
+               try(cxl_region, set_uuid, region, p->uuid);
        }
        try(cxl_region, set_size, region, size);
 

-- 
2.39.1