[9/8] nfsd: fix crash on LOCKT on reexported NFSv3

Commit Message

J. Bruce Fields Aug. 25, 2021, 2:36 a.m. UTC

From: "J. Bruce Fields" <[e-mail]>

Unlike other filesystems, NFSv3 tries to use fl_file in the GETLK case.

Signed-off-by: J. Bruce Fields <[e-mail]>
---
 fs/nfsd/nfs4state.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Patch

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 1b6a7f48982e..4b6d60b46b0a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7043,8 +7043,7 @@  nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 /*
  * The NFSv4 spec allows a client to do a LOCKT without holding an OPEN,
  * so we do a temporary open here just to get an open file to pass to
- * vfs_test_lock.  (Arguably perhaps test_lock should be done with an
- * inode operation.)
+ * vfs_test_lock.
  */
 static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
 {
@@ -7059,7 +7058,9 @@  static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct
 							NFSD_MAY_READ));
 	if (err)
 		goto out;
+	lock->fl_file = nf->nf_file;
 	err = nfserrno(vfs_test_lock(nf->nf_file, lock));
+	lock->fl_file = NULL;
 out:
 	fh_unlock(fhp);
 	nfsd_file_put(nf);