Fix export_args ex_flags field so that is 64bits, the same as mnt_flags.

Since mnt_flags was upgraded to 64bits there has been a quirk in
"struct export_args", since it hold a copy of mnt_flags
in ex_flags, which is an "int" (32bits).
This happens to currently work, since all the flag bits used in ex_flags are
defined in the low order 32bits. However, new export flags cannot be defined.
Also, ex_anon is a "struct xucred", which limits it to 16 additional groups.
This patch revises "struct export_args" to make ex_flags 64bits and replaces
ex_anon with ex_uid, ex_ngroups and ex_groups (which points to a
groups list, so it can be malloc'd up to NGROUPS in size.
This requires that the VFS_CHECKEXP() arguments change, so I also modified the
last "secflavors" argument to be an array pointer, so that the
secflavors could be copied in VFS_CHECKEXP() while the export entry is locked.
(Without this patch VFS_CHECKEXP() returns a pointer to the secflavors
array and then it is used after being unlocked, which is potentially
a problem if the exports entry is changed.
In practice this does not occur when mountd is run with "-S",
but I think it is worth fixing.)

This patch also deleted the vfs_oexport_conv() function, since
do_mount_update() does the conversion, as required by the old vfs_cmount()
calls.

Reviewed by:	kib, freqlabs
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D25088

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/kern/vfs_init.c b/sys/kern/vfs_init.c
index 1e7a5f678469..cbc8bb56ab3e 100644
--- a/sys/kern/vfs_init.c
+++ b/sys/kern/vfs_init.c
@@ -268,8 +268,8 @@ vfs_fhtovp_sigdefer(struct mount *mp, struct fid *fidp, int flags,
 }
 
 static int
-vfs_checkexp_sigdefer(struct mount *mp, struct sockaddr *nam, int *exflg,
-    struct ucred **credp, int *numsecflavors, int **secflavors)
+vfs_checkexp_sigdefer(struct mount *mp, struct sockaddr *nam, uint64_t *exflg,
+    struct ucred **credp, int *numsecflavors, int *secflavors)
 {
 	int prev_stops, rc;