[PATCH 4.11 44/84] Revert "NFS: nfs_rename() handle -ERESTARTSYS dentry left behind"

Greg Kroah-Hartman
2017-07-03T13:48:17Z

From: Benjamin Coddington <bcodding@redhat.com>

commit d9f2950006f110f54444a10442752372ee568289 upstream.

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")
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfs/dir.c | 51 ++++++++++++++++++++++++---------------------------
1 file changed, 24 insertions(+), 27 deletions(-)

--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2002,29 +2002,6 @@ nfs_link(struct dentry *old_dentry, stru
}
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
@@ -2055,7 +2032,7 @@ int nfs_rename(struct inode *old_dir, st
{
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;

@@ -2078,8 +2055,10 @@ int nfs_rename(struct inode *old_dir, st
* 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;
@@ -2096,6 +2075,7 @@ int nfs_rename(struct inode *old_dir, st
goto out;

new_dentry = dentry;
+ rehash = NULL;
new_inode = NULL;
}
}
@@ -2104,8 +2084,7 @@ int nfs_rename(struct inode *old_dir, st
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;
@@ -2115,9 +2094,27 @@ int nfs_rename(struct inode *old_dir, st
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);