[PATCH 6.1 015/451] nfsd: simplify the delayed disposal list code

Sasha Levin
2024-03-24T23:12:23Z

From: Jeff Layton <jlayton@kernel.org>

[ Upstream commit 92e4a6733f922f0fef1d0995f7b2d0eaff86c7ea ]

When queueing a dispose list to the appropriate "freeme" lists, it
pointlessly queues the objects one at a time to an intermediate list.

Remove a few helpers and just open code a list_move to make it more
clear and efficient. Better document the resulting functions with
kerneldoc comments.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfsd/filecache.c | 64 ++++++++++++++++-----------------------------
1 file changed, 22 insertions(+), 42 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 2f0b2d964cbb1..f40d8f3b35a4c 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -402,49 +402,26 @@ nfsd_file_dispose_list(struct list_head *dispose)
}
}

-static void
-nfsd_file_list_remove_disposal(struct list_head *dst,
- struct nfsd_fcache_disposal *l)
-{
- spin_lock(&l->lock);
- list_splice_init(&l->freeme, dst);
- spin_unlock(&l->lock);
-}
-
-static void
-nfsd_file_list_add_disposal(struct list_head *files, struct net *net)
-{
- struct nfsd_net *nn = net_generic(net, nfsd_net_id);
- struct nfsd_fcache_disposal *l = nn->fcache_disposal;
-
- spin_lock(&l->lock);
- list_splice_tail_init(files, &l->freeme);
- spin_unlock(&l->lock);
- queue_work(nfsd_filecache_wq, &l->work);
-}
-
-static void
-nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src,
- struct net *net)
-{
- struct nfsd_file *nf, *tmp;
-
- list_for_each_entry_safe(nf, tmp, src, nf_lru) {
- if (nf->nf_net == net)
- list_move_tail(&nf->nf_lru, dst);
- }
-}
-
+/**
+ * nfsd_file_dispose_list_delayed - move list of dead files to net's freeme list
+ * @dispose: list of nfsd_files to be disposed
+ *
+ * Transfers each file to the "freeme" list for its nfsd_net, to eventually
+ * be disposed of by the per-net garbage collector.
+ */
static void
nfsd_file_dispose_list_delayed(struct list_head *dispose)
{
- LIST_HEAD(list);
- struct nfsd_file *nf;
-
while(!list_empty(dispose)) {
- nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
- nfsd_file_list_add_pernet(&list, dispose, nf->nf_net);
- nfsd_file_list_add_disposal(&list, nf->nf_net);
+ struct nfsd_file *nf = list_first_entry(dispose,
+ struct nfsd_file, nf_lru);
+ struct nfsd_net *nn = net_generic(nf->nf_net, nfsd_net_id);
+ struct nfsd_fcache_disposal *l = nn->fcache_disposal;
+
+ spin_lock(&l->lock);
+ list_move_tail(&nf->nf_lru, &l->freeme);
+ spin_unlock(&l->lock);
+ queue_work(nfsd_filecache_wq, &l->work);
}
}

@@ -665,8 +642,8 @@ nfsd_file_close_inode_sync(struct inode *inode)
* nfsd_file_delayed_close - close unused nfsd_files
* @work: dummy
*
- * Walk the LRU list and destroy any entries that have not been used since
- * the last scan.
+ * Scrape the freeme list for this nfsd_net, and then dispose of them
+ * all.
*/
static void
nfsd_file_delayed_close(struct work_struct *work)
@@ -675,7 +652,10 @@ nfsd_file_delayed_close(struct work_struct *work)
struct nfsd_fcache_disposal *l = container_of(work,
struct nfsd_fcache_disposal, work);

- nfsd_file_list_remove_disposal(&head, l);
+ spin_lock(&l->lock);
+ list_splice_init(&l->freeme, &head);
+ spin_unlock(&l->lock);
+
nfsd_file_dispose_list(&head);
}

--
2.43.0