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Ryusuke Konishi authored
According to syzbot's report, mark_buffer_dirty() called from
nilfs_segctor_do_construct() outputs a warning with some patterns after
nilfs2 detects metadata corruption and degrades to read-only mode.

After such read-only degeneration, page cache data may be cleared through
nilfs_clear_dirty_page() which may also clear the uptodate flag for their
buffer heads.  However, even after the degeneration, log writes are still
performed by unmount processing etc., which causes mark_buffer_dirty() to
be called for buffer heads without the "uptodate" flag and causes the
warning.

Since any writes should not be done to a read-only file system in the
first place, this fixes the warning in mark_buffer_dirty() by letting
nilfs_segctor_do_construct() abort early if in read-only mode.

This also changes the retry check of nilfs_segctor_write_out() to avoid
unnecessary log write retries if it detects -EROFS that
nilfs_segctor_do_construct() returned.

Link: https://lkml.kernel.org/r/20230427011526.13457-1-konishi.ryusuke@gmail.com


Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: default avatarRyusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: default avatar <syzbot+2af3bc9585be7f23f290@syzkaller.appspotmail.com>
  Link: https://syzkaller.appspot.com/bug?extid=2af3bc9585be7f23f290


Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
28a65b49
Linux kernel
============

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Please read the Documentation/process/changes.rst file, as it contains the
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