[ Upstream commit aba2072f452346d56a462718bcde93d697383148 ]
It's OK to grant a read delegation to a client that holds a write,
as long as it's the only client holding the write.
We originally tried to do this in commit 94415b06eb8a ("nfsd4: a
client's own opens needn't prevent delegations"), which had to be
reverted in commit 6ee65a773096 ("Revert "nfsd4: a client's own
opens needn't prevent delegations"").
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 120ce2b0cd52abe73e8b16c23461eb14df5a87d8 ]
To make it easy to tell where files->file_lock protection is being
used when looking up a file create files_lookup_fd_locked. Only allow
this function to be called with the file_lock held.
Update the callers of fcheck and fcheck_files that are called with the
files->file_lock held to call files_lookup_fd_locked instead.
Hopefully this makes it easier to quickly understand what is going on.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-8-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
