In article <2F29CA9A-0AE1-48D3-B3F4-1556912D4C22%me.com@localhost>,
Jason Thorpe <thorpej%me.com@localhost> wrote:
>
>
>> On Sep 14, 2019, at 2:52 PM, Kamil Rytarowski <n54%gmx.com@localhost> wrote:
>>
>> On 14.09.2019 23:34, Christos Zoulas wrote:
>>> Comments?
>>>
>>
>> Question. How does it handle symbolic/hardlinks?
>
>Symbolic links, of course, are simply continuations of the lookup, so
>there's "nothing to see here" with a symbolic link.
If you can get a file desriptor to a symlink, it will work; I don't think
that we have a way to do this now.
>I looked at cache_revlookup() and it looks to me like it simply picks
>the first hit it finds in the hash table for the given vnode.
That is correct.
>At least one platform that support this API uses "the last name the file
>was looked up with", and will fall back on "whatever the underlying file
>system considers to be the canonical name for the file", which is file
>system-defined, if for some reason there is no entry in the name cache
>(which could, for example, happen if an application is doing an
>"open-by-file-id" type operation and the file has not yet been opened by
>path name).
It will also fail if the entry has been evicted from the cache, but that
rarely happens with recently opened files.
if we want to provide this API, it should be done in a reliable way.
"rarely fails" is not reliable enough, IMO.