Fix the new NFS client so that it handles the 64bit fields

that are now in "struct statfs" for NFSv3 and NFSv4. Since
the ffiles value is uint64_t on the wire, I clip the value
to INT64_MAX to avoid setting f_ffree negative.

Tested by:	kib
MFC after:	2 weeks

1 files changed, 23 insertions, 11 deletions

diff --git a/sys/fs/nfsclient/nfs_clport.c b/sys/fs/nfsclient/nfs_clport.c
index 2470a8c..0c3a4c9 100644
--- a/sys/fs/nfsclient/nfs_clport.c
+++ b/sys/fs/nfsclient/nfs_clport.c
@@ -838,21 +838,33 @@ void
 nfscl_loadsbinfo(struct nfsmount *nmp, struct nfsstatfs *sfp, void *statfs)
 {
 	struct statfs *sbp = (struct statfs *)statfs;
-	nfsquad_t tquad;
 
 	if (nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_NFSV4)) {
 		sbp->f_bsize = NFS_FABLKSIZE;
-		tquad.qval = sfp->sf_tbytes;
-		sbp->f_blocks = (long)(tquad.qval / ((u_quad_t)NFS_FABLKSIZE));
-		tquad.qval = sfp->sf_fbytes;
-		sbp->f_bfree = (long)(tquad.qval / ((u_quad_t)NFS_FABLKSIZE));
-		tquad.qval = sfp->sf_abytes;
-		sbp->f_bavail = (long)(tquad.qval / ((u_quad_t)NFS_FABLKSIZE));
-		tquad.qval = sfp->sf_tfiles;
-		sbp->f_files = (tquad.lval[0] & 0x7fffffff);
-		tquad.qval = sfp->sf_ffiles;
-		sbp->f_ffree = (tquad.lval[0] & 0x7fffffff);
+		sbp->f_blocks = sfp->sf_tbytes / NFS_FABLKSIZE;
+		sbp->f_bfree = sfp->sf_fbytes / NFS_FABLKSIZE;
+		/*
+		 * Although sf_abytes is uint64_t and f_bavail is int64_t,
+		 * the value after dividing by NFS_FABLKSIZE is small
+		 * enough that it will fit in 63bits, so it is ok to
+		 * assign it to f_bavail without fear that it will become
+		 * negative.
+		 */
+		sbp->f_bavail = sfp->sf_abytes / NFS_FABLKSIZE;
+		sbp->f_files = sfp->sf_tfiles;
+		/* Since f_ffree is int64_t, clip it to 63bits. */
+		if (sfp->sf_ffiles > INT64_MAX)
+			sbp->f_ffree = INT64_MAX;
+		else
+			sbp->f_ffree = sfp->sf_ffiles;
 	} else if ((nmp->nm_flag & NFSMNT_NFSV4) == 0) {
+		/*
+		 * The type casts to (int32_t) ensure that this code is
+		 * compatible with the old NFS client, in that it will
+		 * propagate bit31 to the high order bits. This may or may
+		 * not be correct for NFSv2, but since it is a legacy
+		 * environment, I'd rather retain backwards compatibility.
+		 */
 		sbp->f_bsize = (int32_t)sfp->sf_bsize;
 		sbp->f_blocks = (int32_t)sfp->sf_blocks;
 		sbp->f_bfree = (int32_t)sfp->sf_bfree;