svn commit: r193041 - head/sys/sys
Edward Tomasz Napierala
trasz at FreeBSD.org
Fri May 29 16:49:46 UTC 2009
On 0529T0948, Scott Long wrote:
> Occasionally it's useful to be able to run older binaries on newer
> kernels.
Yes, not being able to use mount(8) from FreeBSD 7 on a kernel from
FreeBSD 8 would suck. ;-)
> One particularly useful place is for making releases. Does
> this change to struct mount break that? If so, could there be any other
> way to achieve what you want without the breakage?
No, it doesn't break it. Also, I think breaking ABI for mount(8)
because of mount flags won't be neccessary anytime soon - for mounting
and unmounting we have nmount(2), which is extensible by definition,
and to display mounted filesystems, mount(8) uses statfs(2), and f_flags
is int64_t already.
> Edward Tomasz Napierala wrote:
> > Author: trasz
> > Date: Fri May 29 15:00:04 2009
> > New Revision: 193041
> > URL: http://svn.freebsd.org/changeset/base/193041
> >
> > Log:
> > There is only one spare MNT_ flag left, and I want to use it for NFSv4 ACLs.
> > Make room for additional filesystem flags now, to avoid breaking ABI later.
> >
> > Reviewed by: kib@
> >
> > Modified:
> > head/sys/sys/mount.h
> >
> > Modified: head/sys/sys/mount.h
> > ==============================================================================
> > --- head/sys/sys/mount.h Fri May 29 14:42:02 2009 (r193040)
> > +++ head/sys/sys/mount.h Fri May 29 15:00:04 2009 (r193041)
> > @@ -167,6 +167,7 @@ struct mount {
> > int mnt_writeopcount; /* (i) write syscalls pending */
> > int mnt_kern_flag; /* (i) kernel only flags */
> > u_int mnt_flag; /* (i) flags shared with user */
> > + u_int mnt_xflag; /* (i) more flags shared with user */
> > u_int mnt_noasync; /* (i) # noasync overrides */
> > struct vfsoptlist *mnt_opt; /* current mount options */
> > struct vfsoptlist *mnt_optnew; /* new options passed to fs */
> > @@ -221,7 +222,7 @@ void __mnt_vnode_markerfree(str
> > #endif /* _KERNEL */
> >
> > /*
> > - * User specifiable flags.
> > + * User specifiable flags, stored in mnt_flag.
> > */
> > #define MNT_RDONLY 0x00000001 /* read only filesystem */
> > #define MNT_SYNCHRONOUS 0x00000002 /* filesystem written synchronously */
>
--
If you cut off my head, what would I say? Me and my head, or me and my body?
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