NFSv4: Fix problem with OPEN_DOWNGRADE

 RFC 3530 states that for OPEN_DOWNGRADE "The share_access and share_deny
 bits specified must be exactly equal to the union of the share_access and
 share_deny bits specified for some subset of the OPENs in effect for
 current openowner on the current file.

 Setattr is currently violating the NFSv4 rules for OPEN_DOWNGRADE in that
 it may cause a downgrade from OPEN4_SHARE_ACCESS_BOTH to
 OPEN4_SHARE_ACCESS_WRITE despite the fact that there exists no open file
 with O_WRONLY access mode.

 Fix the problem by replacing nfs4_find_state() with a modified version of
 nfs_find_open_context().

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 0 insertions, 33 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 959374d833a7..81d964bfd8a7 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -384,28 +384,6 @@ nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 }
 
 static struct nfs4_state *
-__nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
-{
-        struct nfs_inode *nfsi = NFS_I(inode);
-        struct nfs4_state *state;
-
-        mode &= (FMODE_READ|FMODE_WRITE);
-        list_for_each_entry(state, &nfsi->open_states, inode_states) {
-                if (state->owner->so_cred != cred)
-                        continue;
-                if ((state->state & mode) != mode)
-                        continue;
-                atomic_inc(&state->count);
-                if (mode & FMODE_READ)
-                        state->nreaders++;
-                if (mode & FMODE_WRITE)
-                        state->nwriters++;
-                return state;
-        }
-        return NULL;
-}
-
-static struct nfs4_state *
 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
@@ -423,17 +401,6 @@ __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
         return NULL;
 }
 
-struct nfs4_state *
-nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
-{
-        struct nfs4_state *state;
-
-        spin_lock(&inode->i_lock);
-        state = __nfs4_find_state(inode, cred, mode);
-        spin_unlock(&inode->i_lock);
-        return state;
-}
-
 static void
 nfs4_free_open_state(struct nfs4_state *state)
 {