linux-ext4 - Re: [PATCH] ext4: don't set SB_RDONLY after filesystem errors

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Message-ID: <172476284023.635532.9064427382024981891.b4-ty@mit.edu>
Date: Tue, 27 Aug 2024 08:47:22 -0400
From: "Theodore Ts'o" <tytso@....edu>
To: Jan Kara <jack@...e.cz>
Cc: "Theodore Ts'o" <tytso@....edu>, linux-ext4@...r.kernel.org,
        Christian Brauner <brauner@...nel.org>, linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH] ext4: don't set SB_RDONLY after filesystem errors


On Mon, 05 Aug 2024 22:12:41 +0200, Jan Kara wrote:
> When the filesystem is mounted with errors=remount-ro, we were setting
> SB_RDONLY flag to stop all filesystem modifications. We knew this misses
> proper locking (sb->s_umount) and does not go through proper filesystem
> remount procedure but it has been the way this worked since early ext2
> days and it was good enough for catastrophic situation damage
> mitigation. Recently, syzbot has found a way (see link) to trigger
> warnings in filesystem freezing because the code got confused by
> SB_RDONLY changing under its hands. Since these days we set
> EXT4_FLAGS_SHUTDOWN on the superblock which is enough to stop all
> filesystem modifications, modifying SB_RDONLY shouldn't be needed. So
> stop doing that.
> 
> [...]

Applied, thanks!

[1/1] ext4: don't set SB_RDONLY after filesystem errors
      commit: d3476f3dad4ad68ae5f6b008ea6591d1520da5d8

Best regards,
-- 
Theodore Ts'o <tytso@....edu>