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

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Message-ID: <20230619134204.922713-2-dhowells@redhat.com>
Date:   Mon, 19 Jun 2023 14:42:03 +0100
From:   David Howells <dhowells@...hat.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     David Howells <dhowells@...hat.com>,
        Marc Dionne <marc.dionne@...istor.com>,
        linux-afs@...ts.infradead.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        "Vishal Moola (Oracle)" <vishal.moola@...il.com>
Subject: [PATCH 1/2] afs: Fix dangling folio ref counts in writeback

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

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@...il.com>
Signed-off-by: David Howells <dhowells@...hat.com>
cc: Marc Dionne <marc.dionne@...istor.com>
cc: linux-afs@...ts.infradead.org
Link: https://lore.kernel.org/r/20230607204120.89416-1-vishal.moola@gmail.com/
---
 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;
 					}