[PATCH 1/2] afs: Fix dangling folio ref counts in writeback

From: David Howells
Date: Mon Jun 19 2023 - 09:43:09 EST


From: "Vishal Moola (Oracle)" <vishal.moola@xxxxxxxxx>

Commit acc8d8588cb7 converted afs_writepages_region() to write back a
folio batch. If writeback needs rescheduling, the function exits without
dropping the references to the folios in fbatch. This patch fixes that.

[DH: Moved the added line before the _leave()]

Fixes: acc8d8588cb7 ("afs: convert afs_writepages_region() to use filemap_get_folios_tag()")
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20230607204120.89416-1-vishal.moola@xxxxxxxxx/
---
fs/afs/write.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index c822d6006033..fd433024070e 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -763,6 +763,7 @@ static int afs_writepages_region(struct address_space *mapping,
if (wbc->sync_mode == WB_SYNC_NONE) {
if (skips >= 5 || need_resched()) {
*_next = start;
+ folio_batch_release(&fbatch);
_leave(" = 0 [%llx]", *_next);
return 0;
}