fabrics: Add support for volatile configuration

The fabric resources are global resources and as such should only
modified by one component. So far nvme-cli was the only component
managing connections. With the introduction of nvme-stas we need to
coordinate the access to these resources.

Introduce access coordination feature which allows the external software
to drop volatile configurations files into the /var/nvme directory.

When nvme-cli ls executed(e.g. via the udev rules), the execution
context is evaluated and only resources which belong the application are
considered.

Signed-off-by: Daniel Wagner <dwagner@suse.de>

diff --git a/fabrics.c b/fabrics.c
index 821d0f55ce09771b082a7b1b81cb1e66c3956d47..ac240cad030fcd1e4c2b314654288150c79d98a6 100644 (file)
--- a/fabrics.c
+++ b/fabrics.c
@@ -47,6 +47,7 @@
 
 #define PATH_NVMF_DISC         SYSCONFDIR "/nvme/discovery.conf"
 #define PATH_NVMF_CONFIG       SYSCONFDIR "/nvme/config.json"
+#define PATH_NVMF_RUNDIR       RUNDIR "/nvme"
 #define MAX_DISC_ARGS          32
 #define MAX_DISC_RETRIES       10
 
@@ -84,6 +85,7 @@ static const char *nvmf_hdr_digest    = "enable transport protocol header digest (T
 static const char *nvmf_data_digest    = "enable transport protocol data digest (TCP transport)";
 static const char *nvmf_tls            = "enable TLS";
 static const char *nvmf_config_file    = "Use specified JSON configuration file or 'none' to disable";
+static const char *nvmf_context                = "execution context identification string";
 
 #define NVMF_ARGS(n, c, ...)                                                                     \
        struct argconfig_commandline_options opts[] = {                                          \
@@ -641,6 +643,40 @@ static int discover_from_json_config_file(nvme_root_t r, nvme_host_t h,
        return ret;
 }
 
+static int nvme_read_volatile_config(nvme_root_t r)
+{
+       char *filename, *ext;
+       struct dirent *dir;
+       DIR *d;
+       int ret = -ENOENT;
+
+       d = opendir(PATH_NVMF_RUNDIR);
+       if (!d)
+               return -ENOTDIR;
+
+       while ((dir = readdir(d))) {
+               if (dir->d_type != DT_REG)
+                       continue;
+
+               ext = strchr(dir->d_name, '.');
+               if (!ext || strcmp("json", ext + 1))
+                       continue;
+
+               if (asprintf(&filename, "%s/%s", PATH_NVMF_RUNDIR, dir->d_name) < 0) {
+                       ret = -ENOMEM;
+                       break;
+               }
+
+               if (nvme_read_config(r, filename))
+                       ret = 0;
+
+               free(filename);
+       }
+       closedir(d);
+
+       return ret;
+}
+
 int nvmf_discover(const char *desc, int argc, char **argv, bool connect)
 {
        char *subsysnqn = NVME_DISC_SUBSYS_NAME;
@@ -649,6 +685,7 @@ int nvmf_discover(const char *desc, int argc, char **argv, bool connect)
        char *transport = NULL, *traddr = NULL, *trsvcid = NULL;
        char *config_file = PATH_NVMF_CONFIG;
        char *hnqn = NULL, *hid = NULL;
+       char *context = NULL;
        enum nvme_print_flags flags;
        nvme_root_t r;
        nvme_host_t h;
@@ -675,7 +712,8 @@ int nvmf_discover(const char *desc, int argc, char **argv, bool connect)
                  OPT_FLAG("force",          0, &force,               "Force persistent discovery controller creation"),
                  OPT_FLAG("nbft",           0, &nbft,                "Only look at NBFT tables"),
                  OPT_FLAG("no-nbft",        0, &nonbft,              "Do not look at NBFT tables"),
-                 OPT_STRING("nbft-path",    0, "STR", &nbft_path,    "user-defined path for NBFT tables"));
+                 OPT_STRING("nbft-path",    0, "STR", &nbft_path,    "user-defined path for NBFT tables"),
+                 OPT_STRING("context",      0, "STR", &context,       nvmf_context));
 
        nvmf_default_config(&cfg);
 
@@ -696,6 +734,8 @@ int nvmf_discover(const char *desc, int argc, char **argv, bool connect)
                        nvme_strerror(errno));
                return -errno;
        }
+       if (context)
+               nvme_root_set_application(r, context);
        ret = nvme_scan_topology(r, NULL, NULL);
        if (ret < 0) {
                fprintf(stderr, "Failed to scan topology: %s\n",
@@ -703,8 +743,11 @@ int nvmf_discover(const char *desc, int argc, char **argv, bool connect)
                nvme_free_tree(r);
                return ret;
        }
+
        if (!nvme_read_config(r, config_file))
                json_config = true;
+       if (!nvme_read_volatile_config(r))
+               json_config = true;
 
        hostnqn_arg = hostnqn;
        hostid_arg = hostid;
@@ -820,9 +863,10 @@ int nvmf_discover(const char *desc, int argc, char **argv, bool connect)
                /* No device or non-matching device, create a new controller */
                c = create_discover_ctrl(r, h, &cfg, &trcfg);
                if (!c) {
-                       fprintf(stderr,
-                               "failed to add controller, error %s\n",
-                               nvme_strerror(errno));
+                       if (errno != ENVME_CONNECT_IGNORED)
+                               fprintf(stderr,
+                                       "failed to add controller, error %s\n",
+                                       nvme_strerror(errno));
                        ret = errno;
                        goto out_free;
                }
@@ -851,6 +895,7 @@ int nvmf_connect(const char *desc, int argc, char **argv)
        char *hostkey = NULL, *ctrlkey = NULL;
        char *hnqn = NULL, *hid = NULL;
        char *config_file = PATH_NVMF_CONFIG;
+       char *context = NULL;
        unsigned int verbose = 0;
        nvme_root_t r;
        nvme_host_t h;
@@ -860,12 +905,14 @@ int nvmf_connect(const char *desc, int argc, char **argv)
        struct nvme_fabrics_config cfg = { 0 };
        char *format = "";
 
+
        NVMF_ARGS(opts, cfg,
                  OPT_STRING("dhchap-ctrl-secret", 'C', "STR", &ctrlkey,      nvmf_ctrlkey),
                  OPT_STRING("config",             'J', "FILE", &config_file, nvmf_config_file),
                  OPT_INCR("verbose",              'v', &verbose,             "Increase logging verbosity"),
-                 OPT_FLAG("dump-config",          'O', &dump_config,         "Dump JSON configuration to stdout"),
-                 OPT_FMT("output-format",         'o', &format,              "Output format: normal|json"));
+                 OPT_FLAG("dump-config",          'O', &dump_config,             "Dump JSON configuration to stdout"),
+                 OPT_FMT("output-format",         'o', &format,       "Output format: normal|json"),
+                 OPT_STRING("context",              0, "STR", &context,  nvmf_context));
 
        nvmf_default_config(&cfg);
 
@@ -905,6 +952,8 @@ int nvmf_connect(const char *desc, int argc, char **argv)
                        nvme_strerror(errno));
                return -errno;
        }
+       if (context)
+               nvme_root_set_application(r, context);
        ret = nvme_scan_topology(r, NULL, NULL);
        if (ret < 0) {
                fprintf(stderr, "Failed to scan topology: %s\n",
@@ -913,6 +962,7 @@ int nvmf_connect(const char *desc, int argc, char **argv)
                return ret;
        }
        nvme_read_config(r, config_file);
+       nvme_read_volatile_config(r);
 
        if (!hostnqn)
                hostnqn = hnqn = nvmf_hostnqn_from_file();
@@ -1035,9 +1085,9 @@ int nvmf_disconnect(const char *desc, int argc, char **argv)
        struct config cfg = { 0 };
 
        OPT_ARGS(opts) = {
-               OPT_STRING("nqn",    'n', "NAME", &cfg.nqn,    nvmf_nqn),
-               OPT_STRING("device", 'd', "DEV",  &cfg.device, device),
-               OPT_INCR("verbose",  'v', &cfg.verbose, "Increase logging verbosity"),
+               OPT_STRING("nqn",        'n', "NAME", &cfg.nqn,    nvmf_nqn),
+               OPT_STRING("device",     'd', "DEV",  &cfg.device, device),
+               OPT_INCR("verbose",      'v', &cfg.verbose, "Increase logging verbosity"),
                OPT_END()
        };
 

diff --git a/meson.build b/meson.build
index 944fabc25aaf315d5d9abd480d265d39914cce8d..deb3b9c5bb70d5e12659cd17b782d9cc749e2709 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -27,6 +27,7 @@ sysconfdir = join_paths(prefixdir, get_option('sysconfdir'))
 udevrulesdir   = join_paths(prefixdir, get_option('udevrulesdir'))
 dracutrulesdir = join_paths(prefixdir, get_option('dracutrulesdir'))
 systemddir     = join_paths(prefixdir, get_option('systemddir'))
+rundir         = join_paths(prefixdir, get_option('rundir'))
 
 ###############################################################################
 conf = configuration_data()
@@ -44,6 +45,7 @@ else
 endif
 
 conf.set('SYSCONFDIR', '"@0@"'.format(sysconfdir))
+conf.set('RUNDIR', '"@0@"'.format(rundir))
 
 # Check for libnvme availability
 libnvme_dep = dependency('libnvme', version: '>=1.4', required: true,
@@ -182,6 +184,7 @@ substs.set('DRACUTRILESDIR', dracutrulesdir)
 substs.set('REQUIRES', requires)
 substs.set('DATADIR', datadir)
 substs.set('MANDIR', mandir)
+substs.set('RUNDIR', rundir)
 substs.set('SBINDIR', sbindir)
 substs.set('SYSCONFDIR', sysconfdir)
 substs.set('SYSTEMDDIR', systemddir)
@@ -319,6 +322,7 @@ if meson.version().version_compare('>=0.53.0')
         'mandir':            mandir,
         'udevrulesdir':      udevrulesdir,
         'dracutrulesdir':    dracutrulesdir,
+        'rundir':            rundir,
         'systemddir':        systemddir,
         'build location':    meson.current_build_dir(),
     }

diff --git a/meson_options.txt b/meson_options.txt
index 6c0e7dd9eb3eb9e3f229f638c9f1eae1110597a9..c61dae0fff5640d7e1fd1dbb7e1f4cdb22ce6b97 100644 (file)
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -41,6 +41,12 @@ option(
   value : false,
   description : 'set default Persistent Discovery Controllers behavior'
 )
+option(
+  'rundir',
+  type: 'string',
+  value: 'run',
+  description: 'directory for volatile configuration files',
+)
 option(
   'systemctl',
   type : 'string',