Commit be3df3dd authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
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NFSv4: Don't allow a cached open with a revoked delegation 



If the delegation is marked as being revoked, we must not use it
for cached opens.

Fixes: 869f9dfa ("NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 669996ad

fs/nfs/delegation.c

+10 −0
Original line number Diff line number Diff line
@@ -53,6 +53,16 @@ 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)

{

fs/nfs/delegation.h

+1 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, 
bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, nfs4_stateid *dst, const struct cred **cred);

bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode);



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);

fs/nfs/nfs4proc.c

+2 −5
Original line number Diff line number Diff line
@@ -1440,8 +1440,6 @@ 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:
@@ -1810,7 +1808,6 @@ 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;
@@ -1827,7 +1824,7 @@ 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;
@@ -2371,7 +2368,7 @@ static void nfs4_open_prepare(struct rpc_task *task, void *calldata) 
					data->o_arg.open_flags, claim))

			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();

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