[dm-devel] [PATCH v2 21/23] libmultipath: foreign/nvme: implement path display
Benjamin Marzinski
bmarzins at redhat.com
Wed Mar 7 19:27:16 UTC 2018
On Tue, Mar 06, 2018 at 12:15:05AM +0100, Martin Wilck wrote:
> implement display of path information for NVMe foreign paths and maps.
> With this patch, I get output like this for Linux NVMe soft targets:
>
> nvme-submultipathd show topology
> sys0:NQN:subsysname (uuid.96926ba3-b207-437c-902c-4a4df6538c3f) [nvme] nvme0n1 NVMe,Linux,4.15.0-r
> size=2097152 features='n/a' hwhandler='n/a' wp=rw
> `-+- policy='n/a' prio=n/a status=n/a
> |- 0:1:1 nvme0c1n1 0:0 n/a n/a live
> |- 0:2:1 nvme0c2n1 0:0 n/a n/a live
> |- 0:3:1 nvme0c3n1 0:0 n/a n/a live
> `- 0:4:1 nvme0c4n1 0:0 n/a n/a live
>
> multipathd show paths format '%G %d %i %o %z %m %N'
> foreign dev hcil dev_st serial multipath host WWNN
> [nvme] nvme0c1n1 0:1:1 live 1c2c86659503a02f nvme0n1 rdma:traddr=192.168.201.101,trsvcid=4420
> [nvme] nvme0c2n1 0:2:1 live 1c2c86659503a02f nvme0n1 rdma:traddr=192.168.202.101,trsvcid=4420
> [nvme] nvme0c3n1 0:3:1 live 1c2c86659503a02f nvme0n1 rdma:traddr=192.168.203.101,trsvcid=4420
> [nvme] nvme0c4n1 0:4:1 live 1c2c86659503a02f nvme0n1 rdma:traddr=192.168.204.101,trsvcid=4420
>
> (admittedly, I abused the 'WWNN' wildcard here a bit to display information
> which is helpful for NVMe over RDMA).
>
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>
> Signed-off-by: Martin Wilck <mwilck at suse.com>
> ---
> libmultipath/foreign/nvme.c | 334 ++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 320 insertions(+), 14 deletions(-)
>
> diff --git a/libmultipath/foreign/nvme.c b/libmultipath/foreign/nvme.c
> index 32bd5c96c44a..235f75dd2add 100644
> --- a/libmultipath/foreign/nvme.c
> +++ b/libmultipath/foreign/nvme.c
> @@ -25,42 +25,98 @@
> #include <stdbool.h>
> #include <libudev.h>
> #include <pthread.h>
> +#include <limits.h>
> +#include <dirent.h>
> +#include <errno.h>
> #include "vector.h"
> #include "generic.h"
> #include "foreign.h"
> #include "debug.h"
> +#include "structs.h"
> +#include "sysfs.h"
>
> +static const char nvme_vendor[] = "NVMe";
> +static const char N_A[] = "n/a";
> const char *THIS;
>
> +struct nvme_map;
> +struct nvme_path {
> + struct gen_path gen;
> + struct udev_device *udev;
> + struct udev_device *ctl;
> + struct nvme_map *map;
> + bool seen;
> +};
> +
> +struct nvme_pathgroup {
> + struct gen_pathgroup gen;
> + vector pathvec;
> +};
> +
> struct nvme_map {
> struct gen_multipath gen;
> struct udev_device *udev;
> struct udev_device *subsys;
> dev_t devt;
> + /* Just one static pathgroup for NVMe for now */
> + struct nvme_pathgroup pg;
> + struct gen_pathgroup *gpg;
> + struct _vector pgvec;
> + vector pathvec;
> + int nr_live;
> };
>
> -#define NAME_LEN 64 /* buffer length temp model name */
> +#define NAME_LEN 64 /* buffer length for temp attributes */
> #define const_gen_mp_to_nvme(g) ((const struct nvme_map*)(g))
> #define gen_mp_to_nvme(g) ((struct nvme_map*)(g))
> #define nvme_mp_to_gen(n) &((n)->gen)
> +#define const_gen_pg_to_nvme(g) ((const struct nvme_pathgroup*)(g))
> +#define gen_pg_to_nvme(g) ((struct nvme_pathgroup*)(g))
> +#define nvme_pg_to_gen(n) &((n)->gen)
> +#define const_gen_path_to_nvme(g) ((const struct nvme_path*)(g))
> +#define gen_path_to_nvme(g) ((struct nvme_path*)(g))
> +#define nvme_path_to_gen(n) &((n)->gen)
> +
> +static void cleanup_nvme_path(struct nvme_path *path)
> +{
> + condlog(5, "%s: %p %p", __func__, path, path->udev);
> + if (path->udev)
> + udev_device_unref(path->udev);
> + /* ctl is implicitly referenced by udev, no need to unref */
> + free(path);
> +}
>
> static void cleanup_nvme_map(struct nvme_map *map)
> {
> + if (map->pathvec) {
> + struct nvme_path *path;
> + int i;
> +
> + vector_foreach_slot_backwards(map->pathvec, path, i) {
> + condlog(5, "%s: %d %p", __func__, i, path);
> + cleanup_nvme_path(path);
> + vector_del_slot(map->pathvec, i);
> + }
> + }
> + vector_free(map->pathvec);
> if (map->udev)
> udev_device_unref(map->udev);
> - if (map->subsys)
> - udev_device_unref(map->subsys);
> + /* subsys is implicitly referenced by udev, no need to unref */
> free(map);
> }
>
> static const struct _vector*
> nvme_mp_get_pgs(const struct gen_multipath *gmp) {
> - return NULL;
> + const struct nvme_map *nvme = const_gen_mp_to_nvme(gmp);
> +
> + /* This is all used under the lock, no need to copy */
> + return &nvme->pgvec;
> }
>
> static void
> nvme_mp_rel_pgs(const struct gen_multipath *gmp, const struct _vector *v)
> {
> + /* empty */
> }
>
> static void rstrip(char *str)
> @@ -75,7 +131,6 @@ static int snprint_nvme_map(const struct gen_multipath *gmp,
> char *buff, int len, char wildcard)
> {
> const struct nvme_map *nvm = const_gen_mp_to_nvme(gmp);
> - static const char nvme_vendor[] = "NVMe";
> char fld[NAME_LEN];
> const char *val;
>
> @@ -92,6 +147,8 @@ static int snprint_nvme_map(const struct gen_multipath *gmp,
> return snprintf(buff, len, "%s",
> udev_device_get_sysattr_value(nvm->udev,
> "wwid"));
> + case 'N':
> + return snprintf(buff, len, "%u", nvm->nr_live);
> case 'S':
> return snprintf(buff, len, "%s",
> udev_device_get_sysattr_value(nvm->udev,
> @@ -122,7 +179,7 @@ static int snprint_nvme_map(const struct gen_multipath *gmp,
> case 'G':
> return snprintf(buff, len, "%s", THIS);
> default:
> - return snprintf(buff, len, "N/A");
> + return snprintf(buff, len, N_A);
> break;
> }
> return 0;
> @@ -130,27 +187,101 @@ static int snprint_nvme_map(const struct gen_multipath *gmp,
>
> static const struct _vector*
> nvme_pg_get_paths(const struct gen_pathgroup *gpg) {
> - return NULL;
> + const struct nvme_pathgroup *gp = const_gen_pg_to_nvme(gpg);
> +
> + /* This is all used under the lock, no need to copy */
> + return gp->pathvec;
> }
>
> static void
> nvme_pg_rel_paths(const struct gen_pathgroup *gpg, const struct _vector *v)
> {
> + /* empty */
> }
>
> static int snprint_nvme_pg(const struct gen_pathgroup *gmp,
> char *buff, int len, char wildcard)
> {
> - return 0;
> + return snprintf(buff, len, N_A);
> }
>
> -static int snprint_nvme_path(const struct gen_path *gmp,
> +static int snprint_hcil(const struct nvme_path *np, char *buf, int len)
> +{
> + unsigned int nvmeid, ctlid, nsid;
> + int rc;
> + const char *sysname = udev_device_get_sysname(np->udev);
> +
> + rc = sscanf(sysname, "nvme%uc%un%u", &nvmeid, &ctlid, &nsid);
> + if (rc != 3) {
> + condlog(1, "%s: failed to scan %s", __func__, sysname);
> + rc = snprintf(buf, len, "(ERR:%s)", sysname);
> + } else
> + rc = snprintf(buf, len, "%u:%u:%u", nvmeid, ctlid, nsid);
> + return (rc < len ? rc : len);
> +}
> +
> +static int snprint_nvme_path(const struct gen_path *gp,
> char *buff, int len, char wildcard)
> {
> + const struct nvme_path *np = const_gen_path_to_nvme(gp);
> + dev_t devt;
> + char fld[NAME_LEN];
> + struct udev_device *pci;
> +
> switch (wildcard) {
> + case 'w':
> + return snprintf(buff, len, "%s",
> + udev_device_get_sysattr_value(np->udev,
> + "wwid"));
> + case 'd':
> + return snprintf(buff, len, "%s",
> + udev_device_get_sysname(np->udev));
> + case 'i':
> + return snprint_hcil(np, buff, len);
> + case 'D':
> + devt = udev_device_get_devnum(np->udev);
> + return snprintf(buff, len, "%u:%u", major(devt), minor(devt));
> + case 'o':
> + sysfs_attr_get_value(np->ctl, "state", fld, sizeof(fld));
> + return snprintf(buff, len, "%s", fld);
> + case 's':
> + snprintf(fld, sizeof(fld), "%s",
> + udev_device_get_sysattr_value(np->ctl,
> + "model"));
> + rstrip(fld);
> + return snprintf(buff, len, "%s,%s,%s", nvme_vendor, fld,
> + udev_device_get_sysattr_value(np->ctl,
> + "firmware_rev"));
> + case 'S':
> + return snprintf(buff, len, "%s",
> + udev_device_get_sysattr_value(np->udev,
> + "size"));
> + case 'z':
> + return snprintf(buff, len, "%s",
> + udev_device_get_sysattr_value(np->ctl,
> + "serial"));
> + case 'm':
> + return snprintf(buff, len, "%s",
> + udev_device_get_sysname(np->map->udev));
> + case 'N':
> case 'R':
> - return snprintf(buff, len, "[foreign: %s]", THIS);
> + return snprintf(buff, len, "%s:%s",
> + udev_device_get_sysattr_value(np->ctl,
> + "transport"),
> + udev_device_get_sysattr_value(np->ctl,
> + "address"));
> + case 'G':
> + return snprintf(buff, len, "[%s]", THIS);
> + case 'a':
> + pci = udev_device_get_parent_with_subsystem_devtype(np->ctl,
> + "pci",
> + NULL);
> + if (pci != NULL)
> + return snprintf(buff, len, "PCI:%s",
> + udev_device_get_sysname(pci));
> + /* fall through */
> default:
> + return snprintf(buff, len, "%s", N_A);
> break;
> }
> return 0;
> @@ -176,6 +307,7 @@ static const struct gen_path_ops nvme_path_ops __attribute__((unused)) = {
> struct context {
> pthread_mutex_t mutex;
> vector mpvec;
> + struct udev *udev;
> };
>
> void lock(struct context *ctx)
> @@ -257,6 +389,10 @@ struct context *init(unsigned int api, const char *name)
>
> pthread_mutex_init(&ctx->mutex, NULL);
>
> + ctx->udev = udev_new();
> + if (ctx->udev == NULL)
> + goto err;
> +
> ctx->mpvec = vector_alloc();
> if (ctx->mpvec == NULL)
> goto err;
> @@ -285,6 +421,138 @@ static struct nvme_map *_find_nvme_map_by_devt(const struct context *ctx,
> return NULL;
> }
>
> +static struct nvme_path *
> +_find_path_by_syspath(struct nvme_map *map, const char *syspath)
> +{
> + struct nvme_path *path;
> + char real[PATH_MAX];
> + const char *ppath;
> + int i;
> +
> + ppath = realpath(syspath, real);
> + if (ppath == NULL) {
> + condlog(1, "%s: %s: error in realpath", __func__, THIS);
> + ppath = syspath;
> + }
> +
> + vector_foreach_slot(map->pathvec, path, i) {
> + if (!strcmp(ppath,
> + udev_device_get_syspath(path->udev)))
> + return path;
> + }
> + condlog(4, "%s: %s: %s not found", __func__, THIS, ppath);
> + return NULL;
> +}
> +
> +static int no_dotfiles(const struct dirent *di)
> +{
> + return di->d_name[0] != '.';
> +}
> +
> +static void _find_slaves(struct context *ctx, struct nvme_map *map)
> +{
> + char pathbuf[PATH_MAX];
> + struct dirent **di = NULL;
> + struct nvme_path *path;
> + int r, i;
> +
> + if (map == NULL || map->udev == NULL)
> + return;
> +
> + vector_foreach_slot(map->pathvec, path, i)
> + path->seen = false;
> +
> + snprintf(pathbuf, sizeof(pathbuf),
> + "%s/slaves",
> + udev_device_get_syspath(map->udev));
> +
> + r = scandir(pathbuf, &di, no_dotfiles, alphasort);
> +
> + if (r == 0) {
> + condlog(3, "%s: %s: no paths for %s", __func__, THIS,
> + udev_device_get_sysname(map->udev));
> + return;
> + } else if (r < 0) {
> + condlog(1, "%s: %s: error %d scanning paths of %s", __func__,
> + THIS, errno, udev_device_get_sysname(map->udev));
> + return;
> + }
> +
> + pthread_cleanup_push(free, di);
> + for (i = 0; i < r; i++) {
> + char *fn = di[i]->d_name;
> + struct udev_device *udev;
> +
> + if (snprintf(pathbuf, sizeof(pathbuf), "%s/slaves/%s",
> + udev_device_get_syspath(map->udev), fn)
> + >= sizeof(pathbuf))
> + continue;
> +
> + path = _find_path_by_syspath(map, pathbuf);
> + if (path != NULL) {
> + path->seen = true;
> + condlog(4, "%s: %s already known",
> + __func__, fn);
> + continue;
> + }
> +
> + udev = udev_device_new_from_syspath(ctx->udev, pathbuf);
> + if (udev == NULL) {
> + condlog(1, "%s: %s: failed to get udev device for %s",
> + __func__, THIS, fn);
> + continue;
> + }
> +
> + path = calloc(1, sizeof(*path));
> + if (path == NULL)
> + continue;
> +
> + path->gen.ops = &nvme_path_ops;
> + path->udev = udev;
> + path->seen = true;
> + path->map = map;
> + path->ctl = udev_device_get_parent_with_subsystem_devtype
> + (udev, "nvme", NULL);
> + if (path->ctl == NULL) {
> + condlog(1, "%s: %s: failed to get controller for %s",
> + __func__, THIS, fn);
> + cleanup_nvme_path(path);
> + continue;
> + }
> +
> + if (vector_alloc_slot(map->pathvec) == NULL) {
> + cleanup_nvme_path(path);
> + continue;
> + }
> + condlog(3, "%s: %s: new path %s added to %s",
> + __func__, THIS, udev_device_get_sysname(udev),
> + udev_device_get_sysname(map->udev));
> + vector_set_slot(map->pathvec, path);
> + }
> + pthread_cleanup_pop(1);
> +
> + map->nr_live = 0;
> + vector_foreach_slot_backwards(map->pathvec, path, i) {
> + if (!path->seen) {
> + condlog(1, "path %d not found in %s any more",
> + i, udev_device_get_sysname(map->udev));
> + vector_del_slot(map->pathvec, i);
> + cleanup_nvme_path(path);
> + } else {
> + static const char live_state[] = "live";
> + char state[16];
> +
> + if ((sysfs_attr_get_value(path->ctl, "state", state,
> + sizeof(state)) > 0) &&
> + !strncmp(state, live_state, sizeof(live_state) - 1))
> + map->nr_live++;
> + }
> + }
> + condlog(3, "%s: %s: map %s has %d/%d live paths", __func__, THIS,
> + udev_device_get_sysname(map->udev), map->nr_live,
> + VECTOR_SIZE(map->pathvec));
> +}
> +
> static int _add_map(struct context *ctx, struct udev_device *ud,
> struct udev_device *subsys)
> {
> @@ -307,12 +575,25 @@ static int _add_map(struct context *ctx, struct udev_device *ud,
> map->subsys = subsys;
> map->gen.ops = &nvme_map_ops;
>
> - if (vector_alloc_slot(ctx->mpvec) == NULL) {
> + map->pathvec = vector_alloc();
> + if (map->pathvec == NULL) {
> cleanup_nvme_map(map);
> return FOREIGN_ERR;
> }
>
> + map->pg.gen.ops = &nvme_pg_ops;
> + map->pg.pathvec = map->pathvec;
> + map->gpg = nvme_pg_to_gen(&map->pg);
> +
> + map->pgvec.allocated = 1;
> + map->pgvec.slot = (void**)&map->gpg;
> +
> + if (vector_alloc_slot(ctx->mpvec) == NULL) {
> + cleanup_nvme_map(map);
> + return FOREIGN_ERR;
> + }
> vector_set_slot(ctx->mpvec, map);
> + _find_slaves(ctx, map);
>
> return FOREIGN_CLAIMED;
> }
> @@ -401,9 +682,25 @@ int delete(struct context *ctx, struct udev_device *ud)
> return rc;
> }
>
> +void _check(struct context *ctx)
> +{
> + struct gen_multipath *gm;
> + int i;
> +
> + vector_foreach_slot(ctx->mpvec, gm, i) {
> + struct nvme_map *map = gen_mp_to_nvme(gm);
> +
> + _find_slaves(ctx, map);
> + }
> +}
> +
> void check(struct context *ctx)
> {
> - condlog(5, "%s called for \"%s\"", __func__, THIS);
> + condlog(4, "%s called for \"%s\"", __func__, THIS);
> + lock(ctx);
> + pthread_cleanup_push(unlock, ctx);
> + _check(ctx);
> + pthread_cleanup_pop(1);
> return;
> }
>
> @@ -427,14 +724,23 @@ void release_multipaths(const struct context *ctx, const struct _vector *mpvec)
> */
> const struct _vector * get_paths(const struct context *ctx)
> {
> + vector paths = NULL;
> + const struct gen_multipath *gm;
> + int i;
> +
> condlog(5, "%s called for \"%s\"", __func__, THIS);
> - return NULL;
> + vector_foreach_slot(ctx->mpvec, gm, i) {
> + const struct nvme_map *nm = const_gen_mp_to_nvme(gm);
> + paths = vector_convert(paths, nm->pathvec,
> + struct gen_path, identity);
> + }
> + return paths;
> }
>
> void release_paths(const struct context *ctx, const struct _vector *mpvec)
> {
> condlog(5, "%s called for \"%s\"", __func__, THIS);
> - /* NOP */
> + vector_free_const(mpvec);
> }
>
> /* compile-time check whether all methods are present and correctly typed */
> --
> 2.16.1
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