[src/trunk]: src Allow the user to specify the filesystem ID for umapfs at mo...

[perseant <perseant%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/40cd6aeb24af
branches:  trunk
changeset: 964879:40cd6aeb24af
user:      perseant <perseant%NetBSD.org@localhost>
date:      Tue Aug 20 20:18:54 2019 +0000

description:
Allow the user to specify the filesystem ID for umapfs at mount time,
allowing a consistent filesystem ID across reboots.  Closes PR #54471.

diffstat:

 sbin/mount_umap/mount_umap.8    |   8 +++++++-
 sbin/mount_umap/mount_umap.c    |  19 ++++++++++++++-----
 sys/miscfs/umapfs/umap.h        |   9 +++++----
 sys/miscfs/umapfs/umap_vfsops.c |  31 +++++++++++++++++++++++++++----
 4 files changed, 53 insertions(+), 14 deletions(-)

diffs (195 lines):

diff -r ff58721f8ff1 -r 40cd6aeb24af sbin/mount_umap/mount_umap.8
--- a/sbin/mount_umap/mount_umap.8      Tue Aug 20 18:43:57 2019 +0000
+++ b/sbin/mount_umap/mount_umap.8      Tue Aug 20 20:18:54 2019 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: mount_umap.8,v 1.19 2005/09/11 23:40:43 wiz Exp $
+.\"    $NetBSD: mount_umap.8,v 1.20 2019/08/20 20:18:54 perseant Exp $
 .\"
 .\" Copyright (c) 1992, 1993, 1994
 .\"    The Regents of the University of California.  All rights reserved.
@@ -42,6 +42,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl o Ar options
+.Op Fl i Ar fsid
 .Fl g Ar gid-mapfile
 .Fl u Ar uid-mapfile
 .Ar target
@@ -70,6 +71,11 @@
 Use the group ID mapping specified in
 .Ar gid-mapfile .
 This flag is required.
+.It Fl i Ar fsid
+Use the specified
+.Ar fsid
+for the filesystem ID, rather than choosing one at random.
+This is useful if the filesystem is to be exported.
 .It Fl o
 Options are specified with a
 .Fl o
diff -r ff58721f8ff1 -r 40cd6aeb24af sbin/mount_umap/mount_umap.c
--- a/sbin/mount_umap/mount_umap.c      Tue Aug 20 18:43:57 2019 +0000
+++ b/sbin/mount_umap/mount_umap.c      Tue Aug 20 20:18:54 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mount_umap.c,v 1.23 2011/08/29 14:35:03 joerg Exp $    */
+/*     $NetBSD: mount_umap.c,v 1.24 2019/08/20 20:18:54 perseant Exp $ */
 
 /*
  * Copyright (c) 1992, 1993, 1994
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)mount_umap.c       8.5 (Berkeley) 4/26/95";
 #else
-__RCSID("$NetBSD: mount_umap.c,v 1.23 2011/08/29 14:35:03 joerg Exp $");
+__RCSID("$NetBSD: mount_umap.c,v 1.24 2019/08/20 20:18:54 perseant Exp $");
 #endif
 #endif /* not lint */
 
@@ -104,18 +104,22 @@
        long d1, d2;
        u_long mapdata[MAPFILEENTRIES][2];
        u_long gmapdata[GMAPFILEENTRIES][2];
+       u_long fsid;
        int ch, count, gnentries, mntflags, nentries;
        char *gmapfile, *mapfile, buf[20];
        char source[MAXPATHLEN], target[MAXPATHLEN];
        mntoptparse_t mp;
 
-       mntflags = 0;
+       fsid = mntflags = 0;
        mapfile = gmapfile = NULL;
-       while ((ch = getopt(argc, argv, "g:o:u:")) != -1)
+       while ((ch = getopt(argc, argv, "g:i:o:u:")) != -1)
                switch (ch) {
                case 'g':
                        gmapfile = optarg;
                        break;
+               case 'i':
+                       fsid = strtoul(optarg, NULL, 16);
+                       break;
                case 'o':
                        mp = getmntopts(optarg, mopts, &mntflags, 0);
                        if (mp == NULL)
@@ -246,7 +250,12 @@
        args.mapdata = mapdata;
        args.gnentries = gnentries;
        args.gmapdata = gmapdata;
+       args.fsid = fsid;
 
+       printf("sizeof export_args30 = %d, sizeof layer_args = %d, sizeof umap_args = %d\n",
+               (int)sizeof(struct export_args30),
+               (int)sizeof(struct layer_args),
+               (int)sizeof(struct umap_args));
        if (mount(MOUNT_UMAP, target, mntflags, &args, sizeof args) == -1)
                err(1, "%s on %s", source, target);
        if (mntflags & MNT_GETARGS) {
@@ -260,6 +269,6 @@
 usage(void)
 {
        (void)fprintf(stderr,
-"usage: mount_umap [-o options] -g groupmap -u usermap target_fs mount_point\n");
+"usage: mount_umap [-o options] [-i fsid] -g groupmap -u usermap target_fs mount_point\n");
        exit(1);
 }
diff -r ff58721f8ff1 -r 40cd6aeb24af sys/miscfs/umapfs/umap.h
--- a/sys/miscfs/umapfs/umap.h  Tue Aug 20 18:43:57 2019 +0000
+++ b/sys/miscfs/umapfs/umap.h  Tue Aug 20 20:18:54 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: umap.h,v 1.17 2017/04/11 07:51:37 hannken Exp $        */
+/*     $NetBSD: umap.h,v 1.18 2019/08/20 20:18:54 perseant Exp $       */
 
 /*
  * Copyright (c) 1992, 1993
@@ -51,6 +51,7 @@
        int             gnentries;      /* # of entries in group map array */
        u_long          (*mapdata)[2];  /* pointer to array of user mappings */
        u_long          (*gmapdata)[2]; /* pointer to array of group mappings */
+       u_long          fsid;           /* user-supplied per-fs ident */
 };
 
 #ifdef _KERNEL
@@ -94,11 +95,11 @@
 #define        MOUNTTOUMAPMOUNT(mp) ((struct umap_mount *)((mp)->mnt_data))
 #define        VTOUMAP(vp) ((struct umap_node *)(vp)->v_data)
 #define UMAPTOV(xp) ((xp)->umap_vnode)
-#ifdef UMAPFS_DIAGNOSTIC
+/* #ifdef UMAPFS_DIAGNOSTIC
 #define        UMAPVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
-#else
+#else */
 #define        UMAPVPTOLOWERVP(vp) (VTOUMAP(vp)->umap_lowervp)
-#endif
+/* #endif */
 
 extern int (**umap_vnodeop_p)(void *);
 extern struct vfsops umapfs_vfsops;
diff -r ff58721f8ff1 -r 40cd6aeb24af sys/miscfs/umapfs/umap_vfsops.c
--- a/sys/miscfs/umapfs/umap_vfsops.c   Tue Aug 20 18:43:57 2019 +0000
+++ b/sys/miscfs/umapfs/umap_vfsops.c   Tue Aug 20 20:18:54 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: umap_vfsops.c,v 1.100 2019/02/20 10:06:00 hannken Exp $        */
+/*     $NetBSD: umap_vfsops.c,v 1.101 2019/08/20 20:18:54 perseant Exp $       */
 
 /*
  * Copyright (c) 1992, 1993
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.100 2019/02/20 10:06:00 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.101 2019/08/20 20:18:54 perseant Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -51,6 +51,7 @@
 #include <sys/vnode.h>
 #include <sys/mount.h>
 #include <sys/namei.h>
+#include <sys/syslog.h>
 #include <sys/kauth.h>
 #include <sys/module.h>
 
@@ -79,11 +80,17 @@
 #ifdef UMAPFS_DIAGNOSTIC
        int i;
 #endif
+       fsid_t tfsid;
 
        if (args == NULL)
                return EINVAL;
-       if (*data_len < sizeof *args)
+       if (*data_len < sizeof *args) {
+#ifdef UMAPFS_DIAGNOSTIC
+               printf("mount_umap: data len %d < args %d\n",
+                       (int)*data_len, (int)(sizeof *args));
+#endif
                return EINVAL;
+       }
 
        if (mp->mnt_flag & MNT_GETARGS) {
                amp = MOUNTTOUMAPMOUNT(mp);
@@ -190,7 +197,23 @@
         * Make sure the mount point's sufficiently initialized
         * that the node create call will work.
         */
-       vfs_getnewfsid(mp);
+       tfsid.__fsid_val[0] = (int32_t)args->fsid;
+       tfsid.__fsid_val[1] = makefstype(MOUNT_UMAP);
+       if (tfsid.__fsid_val[0] == 0) {
+               log(LOG_WARNING, "umapfs: fsid given as 0, ignoring\n");
+               vfs_getnewfsid(mp);
+       } else if (vfs_getvfs(&tfsid)) {
+               log(LOG_WARNING, "umapfs: fsid %x already mounted\n",
+                       tfsid.__fsid_val[0]);
+               vfs_getnewfsid(mp);
+       } else {
+                       mp->mnt_stat.f_fsidx.__fsid_val[0] = tfsid.__fsid_val[0];
+                       mp->mnt_stat.f_fsidx.__fsid_val[1] = tfsid.__fsid_val[1];
+               mp->mnt_stat.f_fsid = tfsid.__fsid_val[0];
+       }
+       log(LOG_DEBUG, "umapfs: using fsid %x/%x\n",
+               mp->mnt_stat.f_fsidx.__fsid_val[0],
+               mp->mnt_stat.f_fsidx.__fsid_val[1]);
        mp->mnt_lower = lowerrootvp->v_mount;
 
        amp->umapm_size = sizeof(struct umap_node);