> On Dec 16, 2016, at 06:09, Benjamin Coddington <bcodding@xxxxxxxxxx> wrote:
>
> On 15 Dec 2016, at 17:38, Trond Myklebust wrote:
>
>>> On Dec 15, 2016, at 09:48, Benjamin Coddington <bcodding@xxxxxxxxxx> wrote:
>>>
>>> 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.
>>>
>>> Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
>>> ---
>>> fs/nfs/dir.c | 14 ++++++++++++--
>>> 1 file changed, 12 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
>>> index 5f1af4cd1a33..5d409616f77e 100644
>>> --- a/fs/nfs/dir.c
>>> +++ b/fs/nfs/dir.c
>>> @@ -2100,14 +2100,24 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
>>> d_rehash(rehash);
>>> trace_nfs_rename_exit(old_dir, old_dentry,
>>> new_dir, new_dentry, error);
>>> - if (!error) {
>>> +
>>> + switch (error) {
>>> + 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(new_dir));
>>> - } else if (error == -ENOENT)
>>> + break;
>>> + case -ENOENT:
>>> nfs_dentry_handle_enoent(old_dentry);
>>> + break;
>>> + case -ERESTARTSYS:
>>> + /* The result of the rename is unknown. Play it safe by
>>> + * forcing a new lookup */
>>> + nfs_force_lookup_revalidate(old_dir);
>>> + nfs_force_lookup_revalidate(new_dir);
>>> + }
>>
>> Doesn’t this error handling belong in nfs_async_rename_done(), or possibly in its “data->complete()” callback? There isn’t much point in forcing a new lookup until we know the RPC call has run its course.
>
> That would be more correct, however if moved there, we'd be forcing a lookup after every rename, not just a rename that was signaled. Is it worth trying to find a way to inform those functions that the wait was interrupted?
>
There are already precedents for this. Look, for instance, at how the data->cancelled flag interoperates between nfs4_run_open_task() and
nfs4_open_release() to trigger state recovery (by issuing a close) if the RPC call was completed, but the user interrupted the operation.
Cheers
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