On Wed, 3 Oct 2018 00:40:27 +0000 Rick Macklem <rmack...@uoguelph.ca> wrote:
> Hi, > > I am working on updating "struct export_args" to fix/add a few things. > One of these is that "ex_flags" is an int, but the flags are defined in > mount.h > as MNT_xx bits that now exceed 32bits (mnt_flag is now uint64_t). > For now, this doesn't break anything, since the flags used by ex_flags are > all defined in the low order 32bits but...it seems like this should be > addressed > by a new version of "struct export_args". > > I have two versions of the updated structure: > A) > struct export_args { > uint64_t ex_flags; /* export related flags */ > uid_t ex_root; /* mapping for root uid */ > struct xucred ex_anon; /* mapping for anonymous user */ > struct sockaddr *ex_addr; /* net address to which exported */ > u_char ex_addrlen; /* and the net address length */ > struct sockaddr *ex_mask; /* mask of valid bits in saddr */ > u_char ex_masklen; /* and the smask length */ > char *ex_indexfile; /* index file for WebNFS URLs */ > int ex_numsecflavors; /* security flavor count */ > int ex_secflavors[MAXSECFLAVORS]; /* list of security flavors */ > int32_t ex_fsid; /* mnt_stat.f_fsid.val[0] if */ > /* MNT_EXPORTFSID set in ex_flags64 */ > gid_t *ex_suppgroups; /* Supplemental groups if */ > /* ex_anon.cr_ngroups > XU_NGROUPS */ > }; > B) > struct export_args { > int ex_flags; /* export related flags */ > uid_t ex_root; /* mapping for root uid */ > struct xucred ex_anon; /* mapping for anonymous user */ > struct sockaddr *ex_addr; /* net address to which exported */ > u_char ex_addrlen; /* and the net address length */ > struct sockaddr *ex_mask; /* mask of valid bits in saddr */ > u_char ex_masklen; /* and the smask length */ > char *ex_indexfile; /* index file for WebNFS URLs */ > int ex_numsecflavors; /* security flavor count */ > int ex_secflavors[MAXSECFLAVORS]; /* list of security flavors */ > uint64_t ex_flagshighbits; /* High order bits of mnt_flag */ > int32_t ex_fsid; /* mnt_stat.f_fsid.val[0] if */ > /* MNT_EXPORTFSID set in ex_flags64 */ > gid_t *ex_suppgroups; /* Supplemental groups if */ > /* ex_anon.cr_ngroups > XU_NGROUPS */ > }; > > A) does the obvious thing. Unfortunately, this changes the vfs KABI > (specifically the function vfs_oexport_conv()) such that a file system > module compiled with an unpatched mount.h could crash a patched system. > As such, I think it couldn't be MFC'd and would be stuck in head/current > until FreeBSD13 (or FreeBSD14 if 13 gets skipped over;-). > > B) doesn't change any fields, but adds a second ex_flagshighbits for the high > order bit. Since it only adds fields where none of those bits are used after > the exports are processed by vfs_export() and, as such, will not break > the VFS KABI, since vfs_domount_update() differentiates which version > of export_args is being used. > As such, I believe this version can be MFC'd. However, it does seem confusing > to have the two ex_flags fields for the low and high 32bits. > > So, which do you think it preferable? rick > ps: Josh Paetzel has volunteered to do the mountd.c changes and I have a kerne > patch that I'll put up on phabricator once Josh has been able to test > it. > In B, shouldn't ex_flags become uint32_t if all 32 bits can contain flag bits? And why make ex_flagshighbits a uint64_t? You could make it uint32_t and simply shift the high bits around. -- Gary Jennejohn _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"