From: Trond Myklebust trondmy@gmail.com
[ 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@hammerspace.com Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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();