From: dann frazier Subject: Re: [Bisect] ext4_validate_inode_bitmap:98: comm stress-ng: Corrupt inode bitmap Date: Sat, 14 Jul 2018 05:21:14 -0600 Message-ID: References: <20180706174324.GA3049@xps13.dannf> <20180707041018.GB3546@thunk.org> <20180710165143.GA20459@xps13.dannf> <20180710204329.GB20459@xps13.dannf> <20180712230826.GB28610@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" To: tytso@mit.edu, Ike Pan , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, yanaijie@huawei.com, Colin King , Kamal Mostafa Return-path: In-Reply-To: <20180712230826.GB28610@thunk.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, Jul 12, 2018 at 5:08 PM Theodore Y. Ts'o wrote: > > > > > Review console log and on each run I have filesystem rebuild. The problem > > is that mke2fs I am using is 1.44.3-rc2. I am now reseting the environment > > and re-test. > > > > Could it be that you saw the error in ext4_validate_block_bitmap()? Looks like it. From Ike's report: # grep EXT4 d05-4-ipmi.log [ 26.215587] EXT4-fs (sdb2): mounted filesystem with ordered data mode. Opts: (null) [ 29.844105] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro [ 3586.211348] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383: comm stress-ng: bg 4705: bad block bitmap checksum [ 8254.776992] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383: comm stress-ng: bg 4193: bad block bitmap checksum I've ran my test case for several days w/ just the inode bitmap fix and haven't been able to reproduce it - but perhaps that's just the nature of the chdir test. > The patch which I sent Dann only fixed the problem for inode bitmaps; > I noticed today that we need to fix it for block allocation bitmaps as > well. I've also now ran several iterations w/ the block bitmap fix as well, and still no problems, so: Tested-by: dann frazier > commit 8d5a803c6a6ce4ec258e31f76059ea5153ba46ef > Author: Theodore Ts'o > Date: Thu Jul 12 19:08:05 2018 -0400 > > ext4: check for allocation block validity with block group locked > > With commit 044e6e3d74a3: "ext4: don't update checksum of new > initialized bitmaps" the buffer valid bit will get set without > actually setting up the checksum for the allocation bitmap, since the > checksum will get calculated once we actually allocate an inode or > block. > > If we are doing this, then we need to (re-)check the verified bit > after we take the block group lock. Otherwise, we could race with > another process reading and verifying the bitmap, which would then > complain about the checksum being invalid. > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1780137 > > Signed-off-by: Theodore Ts'o > Cc: stable@kernel.org Would it also make sense to add the following? Fixes: 044e6e3d74a3 ("ext4: don't update checksum of new initialized bitmaps") -dann > diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c > index e68cefe08261..aa52d87985aa 100644 > --- a/fs/ext4/balloc.c > +++ b/fs/ext4/balloc.c > @@ -368,6 +368,8 @@ static int ext4_validate_block_bitmap(struct super_block *sb, > return -EFSCORRUPTED; > > ext4_lock_group(sb, block_group); > + if (buffer_verified(bh)) > + goto verified; > if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group, > desc, bh))) { > ext4_unlock_group(sb, block_group); > @@ -386,6 +388,7 @@ static int ext4_validate_block_bitmap(struct super_block *sb, > return -EFSCORRUPTED; > } > set_buffer_verified(bh); > +verified: > ext4_unlock_group(sb, block_group); > return 0; > } > diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c > index fb83750c1a14..e9d8e2667ab5 100644 > --- a/fs/ext4/ialloc.c > +++ b/fs/ext4/ialloc.c > @@ -90,6 +90,8 @@ static int ext4_validate_inode_bitmap(struct super_block *sb, > return -EFSCORRUPTED; > > ext4_lock_group(sb, block_group); > + if (buffer_verified(bh)) > + goto verified; > blk = ext4_inode_bitmap(sb, desc); > if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh, > EXT4_INODES_PER_GROUP(sb) / 8)) { > @@ -101,6 +103,7 @@ static int ext4_validate_inode_bitmap(struct super_block *sb, > return -EFSBADCRC; > } > set_buffer_verified(bh); > +verified: > ext4_unlock_group(sb, block_group); > return 0; > }