From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B3B3B4431 for ; Wed, 15 Mar 2023 12:40:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2FA25C433D2; Wed, 15 Mar 2023 12:40:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678884044; bh=wzG/d1uqZsRC5ni15sAttM6C+zyO0wtwPZoI2vQ6e4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fIDEA5YoXl13iL0lCRN6jrPdfVMq+Uv3+TI3N7W5IlP7RWsTImn3Ao4QjsvoCLX4S Gf6A+sg7rNyqCzaZ+7UBAsD45pUBBjXP+DGHV5fOkMXf3T9VSFbTZ5Cu4PSbNHrbXu jGUnOSsJwnZqJXBnsmG/jhUj2h1uPzhyr2B64HOM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Filipe Manana , David Sterba , Sasha Levin Subject: [PATCH 6.2 085/141] btrfs: fix extent map logging bit not cleared for split maps after dropping range Date: Wed, 15 Mar 2023 13:13:08 +0100 Message-Id: <20230315115742.566634206@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230315115739.932786806@linuxfoundation.org> References: <20230315115739.932786806@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Filipe Manana [ Upstream commit e4cc1483f35940c9288c332dd275f6fad485f8d2 ] At btrfs_drop_extent_map_range() we are clearing the EXTENT_FLAG_LOGGING bit on a 'flags' variable that was not initialized. This makes static checkers complain about it, so initialize the 'flags' variable before clearing the bit. In practice this has no consequences, because EXTENT_FLAG_LOGGING should not be set when btrfs_drop_extent_map_range() is called, as an fsync locks the inode in exclusive mode, locks the inode's mmap semaphore in exclusive mode too and it always flushes all delalloc. Also add a comment about why we clear EXTENT_FLAG_LOGGING on a copy of the flags of the split extent map. Reported-by: Dan Carpenter Link: https://lore.kernel.org/linux-btrfs/Y%2FyipSVozUDEZKow@kili/ Fixes: db21370bffbc ("btrfs: drop extent map range more efficiently") Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/extent_map.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index be94030e1dfbf..138afa955370b 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -763,7 +763,13 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end, goto next; } + flags = em->flags; clear_bit(EXTENT_FLAG_PINNED, &em->flags); + /* + * In case we split the extent map, we want to preserve the + * EXTENT_FLAG_LOGGING flag on our extent map, but we don't want + * it on the new extent maps. + */ clear_bit(EXTENT_FLAG_LOGGING, &flags); modified = !list_empty(&em->list); @@ -774,7 +780,6 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end, if (em->start >= start && em_end <= end) goto remove_em; - flags = em->flags; gen = em->generation; compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); -- 2.39.2