[Devel] [PATCH hci-8.0 1/2] Revert "fs/fuse: fix fuse file refcount leak on close_wait writeback"

[Liu Kui]

This reverts commit 4c648a077765fdb61aa1298ecb8205b629411fed.

The fix addressed the fuse file refcount leak on close_wait writeback
by moving the wpa's reference acquisition from allocation time back to
submit/promotion time, so that wpas freed without passing through
fuse_writepage_finish() own no reference. Revert it in favor of the
following patch, which fixes the leak while keeping the allocation-time
ownership model of mainline commit 4046d3adcca4 ("fuse: move fuse file
initialization to wpa allocation time") unmodified.

https://virtuozzo.atlassian.net/browse/VSTOR-145614

Signed-off-by: Liu Kui <kui.liu at virtuozzo.com>
---
 fs/fuse/file.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 50d3f8186d39..180f60fc539a 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2181,7 +2181,7 @@ static ssize_t fuse_splice_write(struct pipe_inode_info *pipe, struct file *out,
 static void fuse_writepage_free(struct fuse_writepage_args *wpa)
 {
 	struct fuse_args_pages *ap = &wpa->ia.ap;
-	struct fuse_conn *fc = get_fuse_conn(wpa->inode);
+	struct fuse_conn *fc = wpa->ia.ff->fm->fc;
 	int i;
 
 	if (wpa->bucket)
@@ -2374,7 +2374,6 @@ static void fuse_writepage_end(struct fuse_mount *fm, struct fuse_args *args,
 
 		wpa->next = next->next;
 		next->next = NULL;
-		next->ia.ff = fuse_file_get(wpa->ia.ff);
 		tree_insert(&fi->writepages, next);
 
 		/*
@@ -2524,7 +2523,7 @@ static struct fuse_writepage_args *fuse_writepage_args_setup(struct folio *folio
 	fuse_write_args_fill(&wpa->ia, ff, inode, folio_pos(folio), 0);
 	wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE;
 	wpa->inode = inode;
-	wpa->ia.ff = NULL;
+	wpa->ia.ff = ff;
 
 	ap = &wpa->ia.ap;
 	ap->args.in_pages = true;
@@ -2562,7 +2561,6 @@ static int fuse_writepage_locked(struct folio *folio)
 	if (!wpa)
 		goto err_writepage_args;
 
-	wpa->ia.ff = ff;
 	ap = &wpa->ia.ap;
 	ap->num_pages = 1;
 
@@ -2630,7 +2628,6 @@ static void fuse_writepages_send(struct fuse_fill_wb_data *data)
 	int num_pages = wpa->ia.ap.num_pages;
 	int i;
 
-	wpa->ia.ff = fuse_file_get(data->ff);
 	spin_lock(&fi->lock);
 	list_add_tail(&wpa->queue_entry, &fi->queued_writes);
 	fuse_flush_writepages(inode);
@@ -2794,6 +2791,7 @@ static int fuse_writepages_fill(struct folio *folio,
 			folio_redirty_for_writepage(wbc, folio);
 			goto out_unlock;
 		}
+		fuse_file_get(wpa->ia.ff);
 		data->max_pages = 1;
 		ap = &wpa->ia.ap;
 

-- 
Git-155)