From: Trond Myklebust <trondmy@xxxxxxxxx>
[ Upstream commit be3df3dd4c70ee020587a943a31b98a0fb4b6424 ]
If the delegation is marked as being revoked, we must not use it
for cached opens.
Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfs/delegation.c | 10 ++++++++++
fs/nfs/delegation.h | 1 +
fs/nfs/nfs4proc.c | 7 ++-----
3 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 7af5eeabc80e1..5dac3382405ce 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -52,6 +52,16 @@ nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
return false;
}
+struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
+{
+ struct nfs_delegation *delegation;
+
+ delegation = rcu_dereference(NFS_I(inode)->delegation);
+ if (nfs4_is_valid_delegation(delegation, 0))
+ return delegation;
+ return NULL;
+}
+
static int
nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
{
diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h
index 333063e032f01..26a8af7bdca36 100644
--- a/fs/nfs/delegation.h
+++ b/fs/nfs/delegation.h
@@ -58,6 +58,7 @@ int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state
int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid);
bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode, fmode_t flags);
+struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode);
void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);
int nfs4_have_delegation(struct inode *inode, fmode_t flags);
int nfs4_check_delegation(struct inode *inode, fmode_t flags);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 900a62a9ad4e5..08207001d4753 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1243,8 +1243,6 @@ static int can_open_delegated(struct nfs_delegation *delegation, fmode_t fmode,
return 0;
if ((delegation->type & fmode) != fmode)
return 0;
- if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
- return 0;
switch (claim) {
case NFS4_OPEN_CLAIM_NULL:
case NFS4_OPEN_CLAIM_FH:
@@ -1473,7 +1471,6 @@ static void nfs4_return_incompatible_delegation(struct inode *inode, fmode_t fmo
static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
{
struct nfs4_state *state = opendata->state;
- struct nfs_inode *nfsi = NFS_I(state->inode);
struct nfs_delegation *delegation;
int open_mode = opendata->o_arg.open_flags;
fmode_t fmode = opendata->o_arg.fmode;
@@ -1490,7 +1487,7 @@ static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
}
spin_unlock(&state->owner->so_lock);
rcu_read_lock();
- delegation = rcu_dereference(nfsi->delegation);
+ delegation = nfs4_get_valid_delegation(state->inode);
if (!can_open_delegated(delegation, fmode, claim)) {
rcu_read_unlock();
break;
@@ -1981,7 +1978,7 @@ static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
if (can_open_cached(data->state, data->o_arg.fmode, data->o_arg.open_flags))
goto out_no_action;
rcu_read_lock();
- delegation = rcu_dereference(NFS_I(data->state->inode)->delegation);
+ delegation = nfs4_get_valid_delegation(data->state->inode);
if (can_open_delegated(delegation, data->o_arg.fmode, claim))
goto unlock_no_action;
rcu_read_unlock();
--
2.20.1
