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

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Message-Id: <20230607204120.89416-1-vishal.moola@gmail.com>
Date:   Wed,  7 Jun 2023 13:41:19 -0700
From:   "Vishal Moola (Oracle)" <vishal.moola@...il.com>
To:     linux-afs@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, dhowells@...hat.com,
        akpm@...ux-foundation.org,
        "Vishal Moola (Oracle)" <vishal.moola@...il.com>
Subject: [PATCH] afs: Fix dangling folio ref counts in writeback

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.

This has only been compile tested.

Fixes: acc8d8588cb7 ("afs: convert afs_writepages_region() to use filemap_get_folios_tag()")
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@...il.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..a724228e4d94 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -764,6 +764,7 @@ static int afs_writepages_region(struct address_space *mapping,
 					if (skips >= 5 || need_resched()) {
 						*_next = start;
 						_leave(" = 0 [%llx]", *_next);
+						folio_batch_release(&fbatch);
 						return 0;
 					}
 					skips++;
-- 
2.40.1