Oops, I did my usual and forgot to attach the patch.

Here it is, rick

----- Original Message -----
> Doug Rabson wrote:
> > You could add a single integer-valued vfsopt which holds the
> > high-order
> > bits of f_flags?
> > 
> I have created a patch that does this. It is on
>   https://reviews.freebsd.org/D2506
> (I have also attached it here, for those who don't use Phabricator.)
> 
> Please review/comment on this. (Feel free to add yourself as a
> reviewer, etc.)
> 
> Also, David, if you can test this patch, it would be appreciated.
> 
> Thanks for the suggestion Doug, rick
> 
> > On 7 May 2015 at 02:10, Rick Macklem <rmack...@uoguelph.ca> wrote:
> > 
> > > David Boyd reported a problem to freebsd-current@ w.r.t. the
> > > MNT_AUTOMOUNTED
> > > flag getting cleared by mountd.
> > >   http://docs.FreeBSD.org/cgi/mid.cgi?1429477202.29812.38.camel
> > > I just took a look at this and it's kinda ugly...
> > >
> > > mountd acquires a list of mounts via getmntinfo() and then does
> > > an
> > > nmount() for each of them to get rid of any exports. It uses
> > > f_flags from the statfs returned by getmntinfo() as the 3rd
> > > argument to nmount().
> > > --> Since nmount()s 3rd argument is a "int", it silently drops
> > > any
> > >     MNT_xx flag in the high order 32bits of f_flags. At this
> > >     time,
> > >     it happens that MNT_AUTOMOUNTED is the only one, but...
> > >
> > > I can think of a couple of ways to fix this, but I don't like any
> > > of
> > > them;-)
> > >
> > > 1) I suppose mountd could check for each flag set in f_flags and
> > > generate
> > > a vfsopts string for it, but that means that every time a new
> > > flag
> > > that
> > > can be updated is added to MNT_xx, this mountd.c code would have
> > > to
> > > updated.
> > > --> Ugly!!
> > >
> > > 2) Require that all flags in MNT_UPDATEMASK be in the low order
> > > 32bits.
> > >    I wouldn`t mind this except in means that the MNT_xx flags
> > >    must
> > >    be
> > > redefined
> > >    and I don`t think that could get MFC`d.
> > >
> > > 3) Add a new newernmount(2) which has a 64bit flags argument
> > > instead of
> > > int.
> > >
> > > Hopefully someone can think of a nice way to fix this, rick
> > > _______________________________________________
> > > freebsd-current@freebsd.org mailing list
> > > http://lists.freebsd.org/mailman/listinfo/freebsd-current
> > > To unsubscribe, send any mail to
> > > "freebsd-current-unsubscr...@freebsd.org"
> > >
> > _______________________________________________
> > freebsd-current@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-current
> > To unsubscribe, send any mail to
> > "freebsd-current-unsubscr...@freebsd.org"
> > 
> _______________________________________________
> freebsd-current@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to
> "freebsd-current-unsubscr...@freebsd.org"
> 
--- kern/vfs_mount.c.savmnt	2015-05-09 19:30:14.000000000 -0400
+++ kern/vfs_mount.c	2015-05-10 08:34:45.000000000 -0400
@@ -537,6 +537,7 @@ vfs_donmount(struct thread *td, uint64_t
 	struct vfsopt *opt, *tmp_opt;
 	char *fstype, *fspath, *errmsg;
 	int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
+	uint64_t fsflag_high;
 
 	errmsg = fspath = NULL;
 	errmsg_len = fspathlen = 0;
@@ -653,6 +654,20 @@ vfs_donmount(struct thread *td, uint64_t
 			fsflags |= MNT_AUTOMOUNTED;
 			vfs_freeopt(optlist, opt);
 		}
+		else if (strcmp(opt->name, "fsflaghigh") == 0) {
+			/*
+			 * This option allows a process doing a mount update
+			 * to set all the high order 32bits of mnt_flag with
+			 * one option.  This is needed, since nmount(2)
+			 * accepts an "int" option and, therefore, only takes
+			 * the low order 32bits.
+			 */
+			if (vfs_copyopt(optlist, "fsflaghigh",
+			    &fsflag_high, sizeof(fsflag_high)) == 0 &&
+			    (fsflag_high & 0xffffffffULL) == 0)
+				fsflags |= fsflag_high;
+			vfs_freeopt(optlist, opt);
+		}
 	}
 
 	/*
--- usr.sbin/mountd/mountd.c.orig	2015-05-09 22:04:15.000000000 -0400
+++ usr.sbin/mountd/mountd.c	2015-05-09 22:27:06.000000000 -0400
@@ -1649,6 +1649,7 @@ get_exportlist(void)
 	int iovlen;
 	int done;
 	struct nfsex_args eargs;
+	uint64_t fsflag_high;
 
 	if (suspend_nfsd != 0)
 		(void)nfssvc(NFSSVC_SUSPENDNFSD, NULL);
@@ -1706,6 +1707,8 @@ get_exportlist(void)
 		build_iovec(&iov, &iovlen, "update", NULL, 0);
 		build_iovec(&iov, &iovlen, "export", &export, sizeof(export));
 		build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
+		build_iovec(&iov, &iovlen, "fsflaghigh", &fsflag_high,
+		    sizeof(fsflag_high));
 	}
 
 	for (i = 0; i < num; i++) {
@@ -1736,6 +1739,9 @@ get_exportlist(void)
 		iov[3].iov_len = strlen(fsp->f_mntonname) + 1;
 		iov[5].iov_base = fsp->f_mntfromname;
 		iov[5].iov_len = strlen(fsp->f_mntfromname) + 1;
+		/* Use "fsflaghigh" to set the high order bits of f_flags. */
+		fsflag_high = (fsp->f_flags & 0xffffffff00000000ULL);
+
 		errmsg[0] = '\0';
 
 		/*
@@ -2394,6 +2400,7 @@ do_mount(struct exportlist *ep, struct g
 	int i, iovlen;
 	int ret;
 	struct nfsex_args nfsea;
+	uint64_t fsflag_high;
 
 	eap = &nfsea.export;
 
@@ -2429,6 +2436,12 @@ do_mount(struct exportlist *ep, struct g
 		build_iovec(&iov, &iovlen, "export", eap,
 		    sizeof (struct export_args));
 		build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
+
+		/* Use "fsflaghigh" to set the high order bits of f_flags. */
+		fsflag_high = (fsb->f_flags & 0xffffffff00000000ULL);
+		if (fsflag_high != 0)
+			build_iovec(&iov, &iovlen, "fsflaghigh", &fsflag_high,
+			    sizeof(fsflag_high));
 	}
 
 	while (!done) {
_______________________________________________
freebsd-current@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"

Reply via email to