From patchwork Tue Jul 30 00:52:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 13746035 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 2C1CB63D for ; Tue, 30 Jul 2024 00:53:00 +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=1722300780; cv=none; b=i+SkD/u8GFXJeGbdRQOEDgIdk7ElhgE17evfQtuRdqIaIZDb96rAQvY4Q04QecQCl8b1TOR6Br04FsHDGgjF3o/h+KLZDJJHxqsrNNSsn4+OAvZOcDScadudpP2o2179Ehv44jee3+eCvOcEL0u4TSxMy7hncIfHd1n+J1jnvlQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722300780; c=relaxed/simple; bh=YB6LGPg4laErKm6ba8BGrHDa+oP290ymgPN08DXflNw=; h=Date:Subject:From:To:Cc:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=fHFgolD1FVtZQ5W5sxtGDNfG8n8dqtCyhsJEn2sBlaIx8K+lyKDW6jz0/GklLh9+jeclJGTImkVvsmNipbXbjq4Yi8WGurVAk8pIe2EuRM93GDYzOymkIC7rjbviOYyDH1vr9iXDnqQVDixwiQKZKiw1YDIQHbPkYQWNzkwnExM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lOJUeI04; 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="lOJUeI04" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 030C4C32786; Tue, 30 Jul 2024 00:52:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722300780; bh=YB6LGPg4laErKm6ba8BGrHDa+oP290ymgPN08DXflNw=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=lOJUeI048hJBtWpoewFecTC+3yBrjABhpeBfa+8P7FUBD1fpyHfPcCLfOdxIyrEQ7 rAADQ/tHWu+oAo6LAkPVTjAEVdtVBaLQVx/0CK7eYXnjenWSu08hA2egjeL/nmZk3b ApKyQbDwO7r1Ll+MM8HXGJ9IZUekyNoMdTNSAMhNLUI8TUVAew+z9B8tQbc46VJ+ET YMwZds7Xo4xxrKSqdqPuJhY8guEq9ITe03+GzUV+wpZjcJmcfpEGfusudlRG/A5NRU Y9GzkYf0YbRz8rF1puGJlQbp3VWXtAw1pig/65hwGrqVrkPv74ps2fE1MD+npqpEDZ zSvPCTFNYi94g== Date: Mon, 29 Jul 2024 17:52:59 -0700 Subject: [PATCH 112/115] xfs: make sure sb_fdblocks is non-negative From: "Darrick J. Wong" To: djwong@kernel.org, cem@kernel.org Cc: Wengang Wang , Chandan Babu R , linux-xfs@vger.kernel.org Message-ID: <172229844017.1338752.2042405284909950974.stgit@frogsfrogsfrogs> In-Reply-To: <172229842329.1338752.683513668861748171.stgit@frogsfrogsfrogs> References: <172229842329.1338752.683513668861748171.stgit@frogsfrogsfrogs> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Wengang Wang Source kernel commit: 58f880711f2ba53fd5e959875aff5b3bf6d5c32e A user with a completely full filesystem experienced an unexpected shutdown when the filesystem tried to write the superblock during runtime. kernel shows the following dmesg: [ 8.176281] XFS (dm-4): Metadata corruption detected at xfs_sb_write_verify+0x60/0x120 [xfs], xfs_sb block 0x0 [ 8.177417] XFS (dm-4): Unmount and run xfs_repair [ 8.178016] XFS (dm-4): First 128 bytes of corrupted metadata buffer: [ 8.178703] 00000000: 58 46 53 42 00 00 10 00 00 00 00 00 01 90 00 00 XFSB............ [ 8.179487] 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 8.180312] 00000020: cf 12 dc 89 ca 26 45 29 92 e6 e3 8d 3b b8 a2 c3 .....&E)....;... [ 8.181150] 00000030: 00 00 00 00 01 00 00 06 00 00 00 00 00 00 00 80 ................ [ 8.182003] 00000040: 00 00 00 00 00 00 00 81 00 00 00 00 00 00 00 82 ................ [ 8.182004] 00000050: 00 00 00 01 00 64 00 00 00 00 00 04 00 00 00 00 .....d.......... [ 8.182004] 00000060: 00 00 64 00 b4 a5 02 00 02 00 00 08 00 00 00 00 ..d............. [ 8.182005] 00000070: 00 00 00 00 00 00 00 00 0c 09 09 03 17 00 00 19 ................ [ 8.182008] XFS (dm-4): Corruption of in-memory data detected. Shutting down filesystem [ 8.182010] XFS (dm-4): Please unmount the filesystem and rectify the problem(s) When xfs_log_sb writes super block to disk, b_fdblocks is fetched from m_fdblocks without any lock. As m_fdblocks can experience a positive -> negative -> positive changing when the FS reaches fullness (see xfs_mod_fdblocks). So there is a chance that sb_fdblocks is negative, and because sb_fdblocks is type of unsigned long long, it reads super big. And sb_fdblocks being bigger than sb_dblocks is a problem during log recovery, xfs_validate_sb_write() complains. Fix: As sb_fdblocks will be re-calculated during mount when lazysbcount is enabled, We just need to make xfs_validate_sb_write() happy -- make sure sb_fdblocks is not nenative. This patch also takes care of other percpu counters in xfs_log_sb. Signed-off-by: Wengang Wang Reviewed-by: Darrick J. Wong Signed-off-by: Chandan Babu R --- libxfs/libxfs_priv.h | 2 +- libxfs/xfs_sb.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/libxfs/libxfs_priv.h b/libxfs/libxfs_priv.h index 64bc10e10..5d1aa23c7 100644 --- a/libxfs/libxfs_priv.h +++ b/libxfs/libxfs_priv.h @@ -210,7 +210,7 @@ static inline bool WARN_ON(bool expr) { #define WARN_ON_ONCE(e) WARN_ON(e) #define percpu_counter_read(x) (*x) #define percpu_counter_read_positive(x) ((*x) > 0 ? (*x) : 0) -#define percpu_counter_sum(x) (*x) +#define percpu_counter_sum_positive(x) ((*x) > 0 ? (*x) : 0) /* * get_random_u32 is used for di_gen inode allocation, it must be zero for diff --git a/libxfs/xfs_sb.c b/libxfs/xfs_sb.c index f45ffd994..bedb36a06 100644 --- a/libxfs/xfs_sb.c +++ b/libxfs/xfs_sb.c @@ -1035,11 +1035,12 @@ xfs_log_sb( * and hence we don't need have to update it here. */ if (xfs_has_lazysbcount(mp)) { - mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount); + mp->m_sb.sb_icount = percpu_counter_sum_positive(&mp->m_icount); mp->m_sb.sb_ifree = min_t(uint64_t, - percpu_counter_sum(&mp->m_ifree), + percpu_counter_sum_positive(&mp->m_ifree), mp->m_sb.sb_icount); - mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks); + mp->m_sb.sb_fdblocks = + percpu_counter_sum_positive(&mp->m_fdblocks); } xfs_sb_to_disk(bp->b_addr, &mp->m_sb);