Patch "nfsd: Clean up nfsd_file_put()" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    nfsd: Clean up nfsd_file_put()

to the 5.15-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-clean-up-nfsd_file_put.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b393716274b82ab3e65138f32858f62ab33009bf
Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date:   Thu Mar 31 09:54:02 2022 -0400

    nfsd: Clean up nfsd_file_put()
    
    [ Upstream commit 999397926ab3f78c7d1235cc4ca6e3c89d2769bf ]
    
    Make it a little less racy, by removing the refcount_read() test. Then
    remove the redundant 'is_hashed' variable.
    
    Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 6cde6ef68996e..429ae485ebbbe 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -295,21 +295,14 @@ nfsd_file_put_noref(struct nfsd_file *nf)
 void
 nfsd_file_put(struct nfsd_file *nf)
 {
-	bool is_hashed;
-
 	set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
-	if (refcount_read(&nf->nf_ref) > 2 || !nf->nf_file) {
-		nfsd_file_put_noref(nf);
-		return;
-	}
-
-	is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0;
-	if (!is_hashed) {
+	if (test_bit(NFSD_FILE_HASHED, &nf->nf_flags) == 0) {
 		nfsd_file_flush(nf);
 		nfsd_file_put_noref(nf);
 	} else {
 		nfsd_file_put_noref(nf);
-		nfsd_file_schedule_laundrette();
+		if (nf->nf_file)
+			nfsd_file_schedule_laundrette();
 	}
 	if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT)
 		nfsd_file_gc();