Hi,
This is better I think.
Muhammad Usama Anjum <musamaanjum@xxxxxxxxx> writes:
> @@ -894,6 +891,10 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
>
> /* BB TBD check to see if oplock level check can be removed below */
> if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) {
> + /*
> + * caller expects this func to set the fid in crfid to valid
> + * cached root, so increment the refcount.
> + */
This comment is misleading. crfid variable doesn't exist anymore, and
the kref_get() here is because of this commit:
commit 2f94a3125b87
Author: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Date: Thu Mar 28 11:20:02 2019 +1000
cifs: fix kref underflow in close_shroot()
[...]
--> This extra get() is only used to hold the structure until we get a lease
--> break from the server at which point we will kref_put() it during lease
--> processing.
[...]
When we queue a lease break, we usually get() the cifsFileInfo, but if
that cifsFileInfo is backed by a cached_fid, the cached_fid isn't
bumped. That commit was probably a work around for that.
@Ronnie :
struct cached_fid is starting to look very much like struct
cifsFileInfo. I wonder why we couldn't use it, along with
find_writable_file()/find_readable_file() to handle the caching.
Alternatively, make cifsFileInfo use cached_fid (perhaps renaming it in
the process, I don't know)
Because I suspect a lot more issues will come up regarding cached_fid
refcount and cifsFileInfo refcount going out of sync otherwise.
Cheers,
--
Aurélien Aptel / SUSE Labs Samba Team
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