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From: Josef Bacik <jbacik@fb.com>
To: <linux-btrfs@vger.kernel.org>
Subject: [PATCH] Btrfs: just free dummy extent buffers
Date: Mon, 16 Mar 2015 17:40:48 -0400	[thread overview]
Message-ID: <1426542048-32047-1-git-send-email-jbacik@fb.com> (raw)

If we fail during our sanity tests we could get NULL deref's because we unload
the module before the dummy extent buffers are free'd via RCU.  So check for
this case and just free the things directly.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
---
 fs/btrfs/extent_io.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 29850d4..d13cead 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4968,6 +4968,12 @@ static int release_extent_buffer(struct extent_buffer *eb)
 
 		/* Should be safe to release our pages at this point */
 		btrfs_release_extent_buffer_page(eb);
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+		if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) {
+			__free_extent_buffer(eb);
+			return 1;
+		}
+#endif
 		call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
 		return 1;
 	}
-- 
1.9.3


                 reply	other threads:[~2015-03-16 21:41 UTC|newest]

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