Re: Opps in 2.6.21-rc4 nfsd

[Neil Brown <neilb@suse.de>]

On Monday March 26, neilb@suse.de wrote:
> 
> I'll try to have a patch for you to try on 2.6.21rc4 shortly.
> 

This patch should remove the Oops, but I have a suspicion that
something else is wrong, so I'd be very interested if you could run
with this for a few days and report the results.

NeilBrown

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
 ./fs/nfsd/nfsfh.c |   37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff .prev/fs/nfsd/nfsfh.c ./fs/nfsd/nfsfh.c
--- .prev/fs/nfsd/nfsfh.c	2007-03-26 10:51:01.000000000 +1000
+++ ./fs/nfsd/nfsfh.c	2007-03-26 11:04:20.000000000 +1000
@@ -324,7 +324,7 @@ fh_compose(struct svc_fh *fhp, struct sv
 	 *
 	 */
 
-	u8 version = 1;
+	u8 version;
 	u8 fsid_type = 0;
 	struct inode * inode = dentry->d_inode;
 	struct dentry *parent = dentry->d_parent;
@@ -342,12 +342,45 @@ fh_compose(struct svc_fh *fhp, struct sv
 	 * the reference filehandle (if it is in the same export)
 	 * or the export options.
 	 */
+ retry:
+	version = 1;
 	if (ref_fh && ref_fh->fh_export == exp) {
 		version = ref_fh->fh_handle.fh_version;
 		if (version == 0xca)
 			fsid_type = FSID_DEV;
-		else
+		else {
 			fsid_type = ref_fh->fh_handle.fh_fsid_type;
+			/* need to check that this type works for this
+			 * export point.  As the lookup was done with
+			 * help from user-space, there is no guarantee
+			 */
+			if (ref_fh == fhp)
+				fh_put(ref_fh);
+			ref_fh = NULL;
+			switch(fsid_type) {
+			case FSID_DEV:
+				if (!old_valid_dev(ex_dev))
+					goto retry;
+				break;
+			case FSID_NUM:
+				if (! (exp->ex_flags & NFSEXP_FSID))
+					goto retry;
+				break;
+			case FSID_MAJOR_MINOR:
+			case FSID_ENCODE_DEV:
+				break;
+			case FSID_UUID8:
+			case FSID_UUID16:
+				if (!root_export)
+					goto retry;
+				/* fall through */
+			case FSID_UUID4_INUM:
+			case FSID_UUID16_INUM:
+				if (exp->ex_uuid == NULL)
+					goto retry;
+				break;
+			}
+		}
 		/* We know this version/type works for this export
 		 * so there is no need for further checks.
 		 */