On Wed, 28 May 2008 23:56:12 +0200 Jan Kara <jack@xxxxxxx> wrote: > When underlying block device becomes unavailable (e.g. someone pulling an > USB stick from under us), kernel produces warning about non-uptodate buffer > (superblock) being marked dirty. Silence these warnings by making buffer > uptodate before marking it dirty. > > Signed-off-by: Jan Kara <jack@xxxxxxx> > --- > fs/jbd2/journal.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index 2e24567..55de8f7 100644 > --- a/fs/jbd2/journal.c > +++ b/fs/jbd2/journal.c > @@ -1261,6 +1261,7 @@ void jbd2_journal_update_superblock(journal_t *journal, int wait) > spin_unlock(&journal->j_state_lock); > > BUFFER_TRACE(bh, "marking dirty"); > + set_buffer_uptodate(bh); > mark_buffer_dirty(bh); > if (wait) > sync_dirty_buffer(bh); I have issues.... - Are we really really sure that we aren't about to wreck people's filesystems when this happens? I mean, a non-uptodate buffer might have random garbage in it, and it would be sad to write that to disk. Either way, I do think that potentially falsely setting BH_Uptodate just to squish a WARN_ON_ONCE() is not a good solution. Better to set a new BH_Nowarn, or to call a new mark_buffer_dirty_nowarn() here. - Did the reads of these buffers encounter an IO error? If so, perhaps we could set a new BH_GotIOError or something. Even if I'm completely wrong about everything as usual, I do think that the code change should at least include a comment explaining why the filesystem is doing set_buffer_uptodate() in such a weird place. One nice way of adding that comment would be to implement a new /* * comment goes here */ set_buffer_uptodate_for_mark_buffer_dirty(struct buffer_head *bh); /* needs better name */ and call that. But I agree with me: this looks like abuse of buffer_uptodate(), and a mark_buffer_dirty_nowarn() would be a cleaner solution. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
