Author: cem Date: Fri Jun 5 16:12:21 2020 New Revision: 361838 URL: https://svnweb.freebsd.org/changeset/base/361838
Log: geom_label: Use provider aliasing to alias upstream geoms For synthetic aliases (just pseudonyms inferred from metadata like GPT or UFS labels, GPT UUIDs, etc), use the GEOM provider aliasing system to create a symlink to the real device instead of creating an independent device. This makes it more clear which labels and devices correspond, and we can safely have multiple labels to a single device accessed at once. The confusingly named geom_label on-disk construct continues to behave identically to how it did before. This requires teaching GEOM's provider aliasing about the possibility that aliases might be added later in time, and GEOM's devfs interaction layer not to worry about existing aliases during retaste. Discussed with: imp Relnotes: sure, if we don't end up reverting it Differential Revision: https://reviews.freebsd.org/D24968 Modified: head/sys/geom/geom_dev.c head/sys/geom/label/g_label.c Modified: head/sys/geom/geom_dev.c ============================================================================== --- head/sys/geom/geom_dev.c Fri Jun 5 16:05:09 2020 (r361837) +++ head/sys/geom/geom_dev.c Fri Jun 5 16:12:21 2020 (r361838) @@ -336,9 +336,20 @@ g_dev_taste(struct g_class *mp, struct g_provider *pp, struct cdev *dev, *adev; char buf[SPECNAMELEN + 6]; struct make_dev_args args; + bool retaste; g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name); g_topology_assert(); + /* Only one geom_dev per provider. */ + LIST_FOREACH(cp, &pp->consumers, consumers) { + if (cp->geom->class != mp || (cp->flags & G_CF_SPOILED)) + continue; + gp = cp->geom; + sc = cp->private; + dev = sc->sc_dev; + retaste = true; + goto aliases; + } gp = g_new_geomf(mp, "%s", pp->name); sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO); mtx_init(&sc->sc_mtx, "g_dev", NULL, MTX_DEF); @@ -380,6 +391,8 @@ g_dev_taste(struct g_class *mp, struct g_provider *pp, g_dev_attrchanged(cp, "GEOM::physpath"); snprintf(buf, sizeof(buf), "cdev=%s", gp->name); devctl_notify_f("GEOM", "DEV", "CREATE", buf, M_WAITOK); + retaste = false; +aliases: /* * Now add all the aliases for this drive */ @@ -387,8 +400,16 @@ g_dev_taste(struct g_class *mp, struct g_provider *pp, error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &adev, dev, "%s", gap->ga_alias); if (error) { - printf("%s: make_dev_alias_p() failed (name=%s, error=%d)\n", - __func__, gap->ga_alias, error); + /* + * With aliases added after initial taste, we don't + * know which aliases are new in this retaste, so we + * try to create all of them. EEXIST is expected and + * silently ignored or else this becomes really spammy. + */ + if (error != EEXIST || !retaste) + printf("%s: make_dev_alias_p() failed (name=%s," + " error=%d)\n", __func__, gap->ga_alias, + error); continue; } snprintf(buf, sizeof(buf), "cdev=%s", gap->ga_alias); Modified: head/sys/geom/label/g_label.c ============================================================================== --- head/sys/geom/label/g_label.c Fri Jun 5 16:05:09 2020 (r361837) +++ head/sys/geom/label/g_label.c Fri Jun 5 16:12:21 2020 (r361838) @@ -46,6 +46,7 @@ __FBSDID("$FreeBSD$"); #include <sys/sysctl.h> #include <geom/geom.h> #include <geom/geom_dbg.h> +#include <geom/geom_int.h> #include <geom/geom_slice.h> #include <geom/label/g_label.h> @@ -344,18 +345,16 @@ g_label_taste(struct g_class *mp, struct g_provider *p { struct g_label_metadata md; struct g_consumer *cp; + struct g_class *clsp; struct g_geom *gp; int i; + bool changed; g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name); g_topology_assert(); G_LABEL_DEBUG(2, "Tasting %s.", pp->name); - /* Skip providers that are already open for writing. */ - if (pp->acw > 0) - return (NULL); - if (strcmp(pp->geom->class->name, mp->name) == 0) return (NULL); @@ -391,9 +390,16 @@ g_label_taste(struct g_class *mp, struct g_provider *p if (md.md_provsize != pp->mediasize) break; + /* Skip providers that are already open for writing. */ + if (pp->acw > 0) { + g_access(cp, -1, 0, 0); + goto end; + } + g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR, pp->mediasize - pp->sectorsize); } while (0); + changed = false; for (i = 0; g_labels[i] != NULL; i++) { char label[128]; @@ -405,8 +411,28 @@ g_label_taste(struct g_class *mp, struct g_provider *p g_topology_lock(); if (label[0] == '\0') continue; - g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir, - pp->mediasize); + if (!g_label_is_name_ok(label)) { + G_LABEL_DEBUG(0, + "%s contains suspicious label, skipping.", + pp->name); + G_LABEL_DEBUG(1, "%s suspicious label is: %s", + pp->name, label); + continue; + } + g_provider_add_alias(pp, "%s/%s", g_labels[i]->ld_dir, label); + changed = true; + } + /* + * Force devfs interface to retaste the provider, to catch the new + * alias(es). + */ + if (changed) { + LIST_FOREACH(clsp, &g_classes, class) { + if (strcmp(clsp->name, "DEV") != 0) + continue; + clsp->taste(clsp, pp, 0); + break; + } } g_access(cp, -1, 0, 0); end: _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
