Once we've dropped the flc_lock, there is nothing that ensures that the
delegation that was found will still be around later. Take a reference
to it while holding the lock and then drop it when we've finished with
the delegation.
Fixes: c5967721e106 ("NFSD: handle GETATTR conflict with write delegation")
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index dafff707e23a..19d39872be32 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -8837,7 +8837,6 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
struct file_lock_context *ctx;
struct file_lease *fl;
- struct nfs4_delegation *dp;
struct iattr attrs;
struct nfs4_cb_fattr *ncf;
@@ -8862,7 +8861,8 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,
goto break_lease;
}
if (type == F_WRLCK) {
- dp = fl->c.flc_owner;
+ struct nfs4_delegation *dp = fl->c.flc_owner;
+
if (dp->dl_recall.cb_clp == *(rqstp->rq_lease_breaker)) {
spin_unlock(&ctx->flc_lock);
return 0;
@@ -8870,6 +8870,7 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,
break_lease:
nfsd_stats_wdeleg_getattr_inc(nn);
dp = fl->c.flc_owner;
+ refcount_inc(&dp->dl_stid.sc_count);
ncf = &dp->dl_cb_fattr;
nfs4_cb_getattr(&dp->dl_cb_fattr);
spin_unlock(&ctx->flc_lock);
@@ -8879,8 +8880,10 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,
/* Recall delegation only if client didn't respond */
status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
if (status != nfserr_jukebox ||
- !nfsd_wait_for_delegreturn(rqstp, inode))
+ !nfsd_wait_for_delegreturn(rqstp, inode)) {
+ nfs4_put_stid(&dp->dl_stid);
return status;
+ }
}
if (!ncf->ncf_file_modified &&
(ncf->ncf_initial_cinfo != ncf->ncf_cb_change ||
@@ -8900,6 +8903,7 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,
*size = ncf->ncf_cur_fsize;
*modified = true;
}
+ nfs4_put_stid(&dp->dl_stid);
return 0;
}
break;
--
2.46.0
