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 B2AAF2FE56E; Sat, 6 Dec 2025 14:03:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765029787; cv=none; b=mvhvbosAuH2DunD49qUuYWMjMncFBuix4boErECXP3U+OBORhUVDcb131P6r3/TBiYX4pCb5rLG2r6Yf1vRM8W4QvwWihFPUOUl758wS0kaJi2jH+1O6W08Pw37hh/e+Dtl32qkUdL4j9bM0SyE3XUjnHqEr3UApLaDjqJLpxIA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765029787; c=relaxed/simple; bh=Cv1rkLZwSfO1XqtszF2yVxBBqj1l4Zku5hCFCCY0NwA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YahB10cZD0zm59lwKo9ziXMaOuS3U95ECe+Vfr0FLBPGVC8QYyHcaFsztjI4QmaGb9GbMs1eO12uauvtbDfDnEiT5Vdo1njTVJCPgCp2tVC1SwlYic+CNdgGRrunXY4GiTRKMLB6CegaX6ixOGacMlxJ6Q+b8rXEIBGzW62AvMU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GjoT4CXI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GjoT4CXI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4E72C4CEF5; Sat, 6 Dec 2025 14:03:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765029787; bh=Cv1rkLZwSfO1XqtszF2yVxBBqj1l4Zku5hCFCCY0NwA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GjoT4CXIWDISJjpNHdODKMI7ORpeOM6JM50B7NlcekVvyq3TqvaHAvB/a7Zvv/Ymx RsEk+oVM7wcD7OmlVMfM8PZRkSe/doZE5A77rcmJcgqLzks7u83/ytqI+ZBU5nEXXF ubwEVrPSiCfzza7guhoAszU7xERkvugmxkG7jP5YRud2RxTWPQVSgLVF9x0JIiwokx iOZo7lF4whHR+3RV3j62m9NCJGTKQr5hcdT041NtVRZKC37KIvFWIbaj2+XAWTRZFF Zc3wPgE5nSr7ZHFWBatI5zwGfpfjSfmIssfBVtT9QT8UXR3+VtXOG3A/60oR3JbKAO tm5gukIXMD8gQ== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Qu Wenruo , David Sterba , Sasha Levin , clm@fb.com, linux-btrfs@vger.kernel.org Subject: [PATCH AUTOSEL 6.18-5.10] btrfs: scrub: always update btrfs_scrub_progress::last_physical Date: Sat, 6 Dec 2025 09:02:12 -0500 Message-ID: <20251206140252.645973-7-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251206140252.645973-1-sashal@kernel.org> References: <20251206140252.645973-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.18 Content-Transfer-Encoding: 8bit From: Qu Wenruo [ Upstream commit 54df8b80cc63aa0f22c4590cad11542731ed43ff ] [BUG] When a scrub failed immediately without any byte scrubbed, the returned btrfs_scrub_progress::last_physical will always be 0, even if there is a non-zero @start passed into btrfs_scrub_dev() for resume cases. This will reset the progress and make later scrub resume start from the beginning. [CAUSE] The function btrfs_scrub_dev() accepts a @progress parameter to copy its updated progress to the caller, there are cases where we either don't touch progress::last_physical at all or copy 0 into last_physical: - last_physical not updated at all If some error happened before scrubbing any super block or chunk, we will not copy the progress, leaving the @last_physical untouched. E.g. failed to allocate @sctx, scrubbing a missing device or even there is already a running scrub and so on. All those cases won't touch @progress at all, resulting the last_physical untouched and will be left as 0 for most cases. - Error out before scrubbing any bytes In those case we allocated @sctx, and sctx->stat.last_physical is all zero (initialized by kvzalloc()). Unfortunately some critical errors happened during scrub_enumerate_chunks() or scrub_supers() before any stripe is really scrubbed. In that case although we will copy sctx->stat back to @progress, since no byte is really scrubbed, last_physical will be overwritten to 0. [FIX] Make sure the parameter @progress always has its @last_physical member updated to @start parameter inside btrfs_scrub_dev(). At the very beginning of the function, set @progress->last_physical to @start, so that even if we error out without doing progress copying, last_physical is still at @start. Then after we got @sctx allocated, set sctx->stat.last_physical to @start, this will make sure even if we didn't get any byte scrubbed, at the progress copying stage the @last_physical is not left as zero. This should resolve the resume progress reset problem. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: fs/btrfs/scrub.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index ba20d9286a340..cff67ed630196 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -3039,6 +3039,10 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, unsigned int nofs_flag; bool need_commit = false; + /* Set the basic fallback @last_physical before we got a sctx. */ + if (progress) + progress->last_physical = start; + if (btrfs_fs_closing(fs_info)) return -EAGAIN; @@ -3057,6 +3061,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, sctx = scrub_setup_ctx(fs_info, is_dev_replace); if (IS_ERR(sctx)) return PTR_ERR(sctx); + sctx->stat.last_physical = start; ret = scrub_workers_get(fs_info); if (ret) -- 2.51.0