From 818a8dbe83fddff534b814a7d4e0c75b511dff2e Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Fri, 16 Jun 2017 11:13:00 -0400 Subject: [PATCH] NFS: nfs_rename() - revalidate directories on -ERESTARTSYS An interrupted rename will leave the old dentry behind if the rename succeeds. Fix this by forcing a lookup the next time through ->d_revalidate. A previous attempt at solving this problem took the approach to complete the work of the rename asynchronously, however that approach was wrong since it would allow the d_move() to occur after the directory's i_mutex had been dropped by the original process. Signed-off-by: Benjamin Coddington Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker --- fs/nfs/dir.c | 6 +++++- fs/nfs/unlink.c | 13 +++++++++++++ include/linux/nfs_xdr.h | 1 + 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 9688e9b..ab69ebb 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2056,7 +2056,11 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, } error = rpc_wait_for_completion_task(task); - if (error == 0) + if (error != 0) { + ((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1; + /* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */ + smp_wmb(); + } else error = task->tk_status; rpc_put_task(task); out: diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c index 191aa57..e3949d9 100644 --- a/fs/nfs/unlink.c +++ b/fs/nfs/unlink.c @@ -288,6 +288,19 @@ static void nfs_async_rename_release(void *calldata) if (d_really_is_positive(data->old_dentry)) nfs_mark_for_revalidate(d_inode(data->old_dentry)); + /* The result of the rename is unknown. Play it safe by + * forcing a new lookup */ + if (data->cancelled) { + spin_lock(&data->old_dir->i_lock); + nfs_force_lookup_revalidate(data->old_dir); + spin_unlock(&data->old_dir->i_lock); + if (data->new_dir != data->old_dir) { + spin_lock(&data->new_dir->i_lock); + nfs_force_lookup_revalidate(data->new_dir); + spin_unlock(&data->new_dir->i_lock); + } + } + dput(data->old_dentry); dput(data->new_dentry); iput(data->old_dir); diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 9b42bff..9463eef 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -1533,6 +1533,7 @@ struct nfs_renamedata { struct nfs_fattr new_fattr; void (*complete)(struct rpc_task *, struct nfs_renamedata *); long timeout; + bool cancelled; }; struct nfs_access_entry; -- 2.7.4