NFS: Fix the ftruncate() credential problem

ftruncate() access checking is supposed to be performed at open() time,
just like reads and writes.

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

1 files changed, 23 insertions, 24 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 26fbeb3467cb..31a7e4c54a12 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1139,8 +1139,9 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir, struct path *path, int
         return res;
 }
 
-static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
-                struct iattr *sattr, struct nfs4_state *state)
+static int _nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred,
+                            struct nfs_fattr *fattr, struct iattr *sattr,
+                            struct nfs4_state *state)
 {
         struct nfs_server *server = NFS_SERVER(inode);
         struct nfs_setattrargs  arg = {
@@ -1154,9 +1155,10 @@ static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
                 .server         = server,
         };
         struct rpc_message msg = {
-                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
-                .rpc_argp       = &arg,
-                .rpc_resp       = &res,
+                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
+                .rpc_argp       = &arg,
+                .rpc_resp       = &res,
+                .rpc_cred       = cred,
         };
         unsigned long timestamp = jiffies;
         int status;
@@ -1166,7 +1168,6 @@ static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
         if (nfs4_copy_delegation_stateid(&arg.stateid, inode)) {
                 /* Use that stateid */
         } else if (state != NULL) {
-                msg.rpc_cred = state->owner->so_cred;
                 nfs4_copy_stateid(&arg.stateid, state, current->files);
         } else
                 memcpy(&arg.stateid, &zero_stateid, sizeof(arg.stateid));
@@ -1177,15 +1178,16 @@ static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
         return status;
 }
 
-static int nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
-                struct iattr *sattr, struct nfs4_state *state)
+static int nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred,
+                           struct nfs_fattr *fattr, struct iattr *sattr,
+                           struct nfs4_state *state)
 {
         struct nfs_server *server = NFS_SERVER(inode);
         struct nfs4_exception exception = { };
         int err;
         do {
                 err = nfs4_handle_exception(server,
-                                _nfs4_do_setattr(inode, fattr, sattr, state),
+                                _nfs4_do_setattr(inode, cred, fattr, sattr, state),
                                 &exception);
         } while (exception.retry);
         return err;
@@ -1647,29 +1649,25 @@ static int
 nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
                   struct iattr *sattr)
 {
-        struct rpc_cred *cred;
         struct inode *inode = dentry->d_inode;
-        struct nfs_open_context *ctx;
+        struct rpc_cred *cred = NULL;
         struct nfs4_state *state = NULL;
         int status;
 
         nfs_fattr_init(fattr);
         
-        cred = rpc_lookup_cred();
-        if (IS_ERR(cred))
-                return PTR_ERR(cred);
-
         /* Search for an existing open(O_WRITE) file */
-        ctx = nfs_find_open_context(inode, cred, FMODE_WRITE);
-        if (ctx != NULL)
+        if (sattr->ia_valid & ATTR_FILE) {
+                struct nfs_open_context *ctx;
+
+                ctx = nfs_file_open_context(sattr->ia_file);
+                cred = ctx->cred;
                 state = ctx->state;
+        }
 
-        status = nfs4_do_setattr(inode, fattr, sattr, state);
+        status = nfs4_do_setattr(inode, cred, fattr, sattr, state);
         if (status == 0)
                 nfs_setattr_update_inode(inode, sattr);
-        if (ctx != NULL)
-                put_nfs_open_context(ctx);
-        put_rpccred(cred);
         return status;
 }
 
@@ -1897,17 +1895,16 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                 goto out;
         }
         state = nfs4_do_open(dir, &path, flags, sattr, cred);
-        put_rpccred(cred);
         d_drop(dentry);
         if (IS_ERR(state)) {
                 status = PTR_ERR(state);
-                goto out;
+                goto out_putcred;
         }
         d_add(dentry, igrab(state->inode));
         nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
         if (flags & O_EXCL) {
                 struct nfs_fattr fattr;
-                status = nfs4_do_setattr(state->inode, &fattr, sattr, state);
+                status = nfs4_do_setattr(state->inode, cred, &fattr, sattr, state);
                 if (status == 0)
                         nfs_setattr_update_inode(state->inode, sattr);
                 nfs_post_op_update_inode(state->inode, &fattr);
@@ -1916,6 +1913,8 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                 status = nfs4_intent_set_file(nd, &path, state);
         else
                 nfs4_close_sync(&path, state, flags);
+out_putcred:
+        put_rpccred(cred);
 out:
         return status;
 }