This is a note to let you know that I've just added the patch titled
nfsd: Cache R, RW, and W opens separately
to the 5.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-cache-r-rw-and-w-opens-separately.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c44e2a49ba731107b9fed6306edc428e7eb55b43
Author: J. Bruce Fields <bfields@xxxxxxxxxx>
Date: Fri Jul 17 18:54:54 2020 -0400
nfsd: Cache R, RW, and W opens separately
[ Upstream commit ae3c57b5ca47665dc3416447a5534a9796096d86 ]
The nfsd open code has always kept separate read-only, read-write, and
write-only opens as necessary to ensure that when a client closes or
downgrades, we don't retain more access than necessary.
Also, I didn't realize the cache behaved this way when I wrote
94415b06eb8a "nfsd4: a client's own opens needn't prevent delegations".
There I assumed fi_fds[O_WRONLY] and fi_fds[O_RDWR] would always be
distinct. The violation of that assumption is triggering a
WARN_ON_ONCE() and could also cause the server to give out a delegation
when it shouldn't.
Fixes: 94415b06eb8a ("nfsd4: a client's own opens needn't prevent delegations")
Tested-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index c8b9d2667ee6f..3c6c2f7d1688b 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -889,7 +889,7 @@ nfsd_file_find_locked(struct inode *inode, unsigned int may_flags,
hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head,
nf_node, lockdep_is_held(&nfsd_file_hashtbl[hashval].nfb_lock)) {
- if ((need & nf->nf_may) != need)
+ if (nf->nf_may != need)
continue;
if (nf->nf_inode != inode)
continue;
