Revert "NFS: nfs_rename() handle -ERESTARTSYS dentry left behind"

This reverts commit 920b4530fb80430ff30ef83efe21ba1fa5623731 which could
call d_move() without holding the directory's i_mutex, and reverts commit
d4ea7e3c5c0e341c15b073016dbf3ab6c65f12f3 "NFS: Fix old dentry rehash after
move", which was a follow-up fix.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: 920b4530fb80 ("NFS: nfs_rename() handle -ERESTARTSYS dentry left behind")
Cc: stable@vger.kernel.org # v4.10+
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 32ccd7754f8a2875933d1f9c532b54c656971bfd..2ac00bf4ecf146815bff44755f4406161e569007 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1946,29 +1946,6 @@ nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 }
 EXPORT_SYMBOL_GPL(nfs_link);
 
-static void
-nfs_complete_rename(struct rpc_task *task, struct nfs_renamedata *data)
-{
-       struct dentry *old_dentry = data->old_dentry;
-       struct dentry *new_dentry = data->new_dentry;
-       struct inode *old_inode = d_inode(old_dentry);
-       struct inode *new_inode = d_inode(new_dentry);
-
-       nfs_mark_for_revalidate(old_inode);
-
-       switch (task->tk_status) {
-       case 0:
-               if (new_inode != NULL)
-                       nfs_drop_nlink(new_inode);
-               d_move(old_dentry, new_dentry);
-               nfs_set_verifier(new_dentry,
-                                       nfs_save_change_attribute(data->new_dir));
-               break;
-       case -ENOENT:
-               nfs_dentry_handle_enoent(old_dentry);
-       }
-}
-
 /*
  * RENAME
  * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
@@ -1999,7 +1976,7 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 {
        struct inode *old_inode = d_inode(old_dentry);
        struct inode *new_inode = d_inode(new_dentry);
-       struct dentry *dentry = NULL;
+       struct dentry *dentry = NULL, *rehash = NULL;
        struct rpc_task *task;
        int error = -EBUSY;
 
@@ -2022,8 +1999,10 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                 * To prevent any new references to the target during the
                 * rename, we unhash the dentry in advance.
                 */
-               if (!d_unhashed(new_dentry))
+               if (!d_unhashed(new_dentry)) {
                        d_drop(new_dentry);
+                       rehash = new_dentry;
+               }
 
                if (d_count(new_dentry) > 2) {
                        int err;
@@ -2040,6 +2019,7 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                                goto out;
 
                        new_dentry = dentry;
+                       rehash = NULL;
                        new_inode = NULL;
                }
        }
@@ -2048,8 +2028,7 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        if (new_inode != NULL)
                NFS_PROTO(new_inode)->return_delegation(new_inode);
 
-       task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry,
-                                       nfs_complete_rename);
+       task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry, NULL);
        if (IS_ERR(task)) {
                error = PTR_ERR(task);
                goto out;
@@ -2059,9 +2038,27 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        if (error == 0)
                error = task->tk_status;
        rpc_put_task(task);
+       nfs_mark_for_revalidate(old_inode);
 out:
+       if (rehash)
+               d_rehash(rehash);
        trace_nfs_rename_exit(old_dir, old_dentry,
                        new_dir, new_dentry, error);
+       if (!error) {
+               if (new_inode != NULL)
+                       nfs_drop_nlink(new_inode);
+               /*
+                * The d_move() should be here instead of in an async RPC completion
+                * handler because we need the proper locks to move the dentry.  If
+                * we're interrupted by a signal, the async RPC completion handler
+                * should mark the directories for revalidation.
+                */
+               d_move(old_dentry, new_dentry);
+               nfs_set_verifier(new_dentry,
+                                       nfs_save_change_attribute(new_dir));
+       } else if (error == -ENOENT)
+               nfs_dentry_handle_enoent(old_dentry);
+
        /* new dentry created? */
        if (dentry)
                dput(dentry);