diff options
| -rw-r--r-- | sys/geom/geom_bsd.c | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/sys/geom/geom_bsd.c b/sys/geom/geom_bsd.c index 7d51896..27c4c8a 100644 --- a/sys/geom/geom_bsd.c +++ b/sys/geom/geom_bsd.c @@ -36,7 +36,7 @@ * * This is the method for dealing with BSD disklabels. It has been * extensively (by my standards at least) commented, in the vain hope that - * it will server as the source in future copy&paste operations. + * it will serve as the source in future copy&paste operations. */ #include <sys/param.h> @@ -56,6 +56,7 @@ #include <sys/mutex.h> #endif #include <sys/stdint.h> +#include <sys/md5.h> #include <sys/errno.h> #include <sys/disklabel.h> #include <geom/geom.h> @@ -76,6 +77,7 @@ struct g_bsd_softc { off_t rawoffset; struct disklabel ondisk; struct disklabel inram; + u_char labelsum[16]; }; /* @@ -627,6 +629,10 @@ g_bsd_start(struct bio *bp) g_call_me(g_bsd_hotwrite, bp); return (EJUSTRETURN); case BIO_GETATTR: + if (g_handleattr(bp, "BSD::labelsum", ms->labelsum, + sizeof(ms->labelsum))) + return (1); + break; case BIO_SETATTR: break; default: @@ -723,6 +729,8 @@ g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags) struct disklabel *dl; u_int secsize; struct g_slicer *gsp; + MD5_CTX md5sum; + u_char hash[16]; g_trace(G_T_TOPOLOGY, "bsd_taste(%s,%s)", mp->name, pp->name); g_topology_assert(); @@ -732,15 +740,6 @@ g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags) return (NULL); /* - * The BSD-method will not automatically configure itself recursively - * Note that it is legal to examine the class-name of our provider, - * nothing else should ever be examined inside the provider. - */ - if (flags == G_TF_NORMAL && - !strcmp(pp->geom->class->name, BSD_CLASS_NAME)) - return (NULL); - - /* * BSD labels are a subclass of the general "slicing" topology so * a lot of the work can be done by the common "slice" code. * Create a geom with space for MAXPARTITIONS providers, one consumer @@ -779,7 +778,7 @@ g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags) /* * If the provider is an MBR we will only auto attach * to type 165 slices in the G_TF_NORMAL case. We will - * attach to any other type (BSD was handles above) + * attach to any other type. */ error = g_getattr("MBR::type", cp, &i); if (!error) { @@ -818,10 +817,25 @@ g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags) break; /* + * In order to avoid recursively attaching to the same + * on-disk label (it's usually visible through the 'c' + * partition) we calculate an MD5 and ask if other BSD's + * below us love that label. If they do, we don't. + */ + + dl = &ms->inram; + MD5Init(&md5sum); + MD5Update(&md5sum, (u_char *)dl, sizeof(dl)); + MD5Final(ms->labelsum, &md5sum); + + error = g_getattr("BSD::labelsum", cp, &hash); + if (!error && !strncmp(ms->labelsum, hash, sizeof(hash))) + break; + + /* * Process the found disklabel, and modify our "slice" * instance to match it, if possible. */ - dl = &ms->inram; error = g_bsd_modify(gp, dl); /* Picks up topology lock. */ if (!error) g_topology_unlock(); |
