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authorJeff Layton <jlayton@kernel.org>2023-01-20 14:52:14 -0500
committerChuck Lever <chuck.lever@oracle.com>2023-01-23 09:51:17 -0500
commit4bdbba54e9b1c769da8ded9abd209d765715e1d6 (patch)
tree5dc3af2ca14cef52d2d784375062ed04acc6d21d
parent7c24fa225081f31bc6da6a355c1ba801889ab29a (diff)
downloadlinux-4bdbba54e9b1c769da8ded9abd209d765715e1d6.tar.bz2
nfsd: don't free files unconditionally in __nfsd_file_cache_purge
nfsd_file_cache_purge is called when the server is shutting down, in which case, tearing things down is generally fine, but it also gets called when the exports cache is flushed. Instead of walking the cache and freeing everything unconditionally, handle it the same as when we have a notification of conflicting access. Fixes: ac3a2585f018 ("nfsd: rework refcounting in filecache") Reported-by: Ruben Vestergaard <rubenv@drcmr.dk> Reported-by: Torkil Svensgaard <torkil@drcmr.dk> Reported-by: Shachar Kagan <skagan@nvidia.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Tested-by: Shachar Kagan <skagan@nvidia.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
-rw-r--r--fs/nfsd/filecache.c61
1 files changed, 36 insertions, 25 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 0ef070349014..c0950edb26b0 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -662,6 +662,39 @@ static struct shrinker nfsd_file_shrinker = {
};
/**
+ * nfsd_file_cond_queue - conditionally unhash and queue a nfsd_file
+ * @nf: nfsd_file to attempt to queue
+ * @dispose: private list to queue successfully-put objects
+ *
+ * Unhash an nfsd_file, try to get a reference to it, and then put that
+ * reference. If it's the last reference, queue it to the dispose list.
+ */
+static void
+nfsd_file_cond_queue(struct nfsd_file *nf, struct list_head *dispose)
+ __must_hold(RCU)
+{
+ int decrement = 1;
+
+ /* If we raced with someone else unhashing, ignore it */
+ if (!nfsd_file_unhash(nf))
+ return;
+
+ /* If we can't get a reference, ignore it */
+ if (!nfsd_file_get(nf))
+ return;
+
+ /* Extra decrement if we remove from the LRU */
+ if (nfsd_file_lru_remove(nf))
+ ++decrement;
+
+ /* If refcount goes to 0, then put on the dispose list */
+ if (refcount_sub_and_test(decrement, &nf->nf_ref)) {
+ list_add(&nf->nf_lru, dispose);
+ trace_nfsd_file_closing(nf);
+ }
+}
+
+/**
* nfsd_file_queue_for_close: try to close out any open nfsd_files for an inode
* @inode: inode on which to close out nfsd_files
* @dispose: list on which to gather nfsd_files to close out
@@ -688,30 +721,11 @@ nfsd_file_queue_for_close(struct inode *inode, struct list_head *dispose)
rcu_read_lock();
do {
- int decrement = 1;
-
nf = rhashtable_lookup(&nfsd_file_rhash_tbl, &key,
nfsd_file_rhash_params);
if (!nf)
break;
-
- /* If we raced with someone else unhashing, ignore it */
- if (!nfsd_file_unhash(nf))
- continue;
-
- /* If we can't get a reference, ignore it */
- if (!nfsd_file_get(nf))
- continue;
-
- /* Extra decrement if we remove from the LRU */
- if (nfsd_file_lru_remove(nf))
- ++decrement;
-
- /* If refcount goes to 0, then put on the dispose list */
- if (refcount_sub_and_test(decrement, &nf->nf_ref)) {
- list_add(&nf->nf_lru, dispose);
- trace_nfsd_file_closing(nf);
- }
+ nfsd_file_cond_queue(nf, dispose);
} while (1);
rcu_read_unlock();
}
@@ -928,11 +942,8 @@ __nfsd_file_cache_purge(struct net *net)
nf = rhashtable_walk_next(&iter);
while (!IS_ERR_OR_NULL(nf)) {
- if (!net || nf->nf_net == net) {
- nfsd_file_unhash(nf);
- nfsd_file_lru_remove(nf);
- list_add(&nf->nf_lru, &dispose);
- }
+ if (!net || nf->nf_net == net)
+ nfsd_file_cond_queue(nf, &dispose);
nf = rhashtable_walk_next(&iter);
}