On Fri, Sep 15, 2023 at 03:57:34PM +0300, Dan Carpenter wrote: > Hello Kent Overstreet, > > The patch 93a640e2570b: "bcachefs: GFP_NOIO -> GFP_NOFS" from May 28, > 2023 (linux-next), leads to the following Smatch static checker > warning: > > fs/bcachefs/journal_io.c:1461 journal_buf_realloc() warn: sleeping in atomic > context > fs/bcachefs/journal_io.c:1662 bch2_journal_entries_postprocess() warn: > sleeping in atomic context > fs/bcachefs/journal_io.c:1764 bch2_journal_write() warn: sleeping in atomic > context > fs/bcachefs/journal_io.c:788 jset_validate() warn: sleeping in atomic context > fs/bcachefs/replicas.c:439 bch2_mark_replicas() warn: sleeping in atomic > context > > All this sleeping in atomic warnings start in journal_write_done() > where it takes spin_lock(&j->lock) so preempt is disabled.
>From 0528bebd8b42ce43a39da8e911bf21825f5085dd Mon Sep 17 00:00:00 2001 From: Kent Overstreet <[email protected]> Date: Tue, 19 Sep 2023 22:36:30 -0400 Subject: [PATCH] bcachefs: drop journal lock before calling journal_write bch2_journal_write() expects process context, it takes journal_lock as needed. Reported-by: Dan Carpenter <[email protected]> Signed-off-by: Kent Overstreet <[email protected]> diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c index 269c8e8a1d95..6a3d6a374e9c 100644 --- a/fs/bcachefs/journal_io.c +++ b/fs/bcachefs/journal_io.c @@ -1554,6 +1554,7 @@ static void journal_write_done(struct closure *cl) if (!journal_state_count(new, new.unwritten_idx) && journal_last_unwritten_seq(j) <= journal_cur_seq(j)) { + spin_unlock(&j->lock); closure_call(&j->io, bch2_journal_write, c->io_complete_wq, NULL); } else if (journal_last_unwritten_seq(j) == journal_cur_seq(j) && new.cur_entry_offset < JOURNAL_ENTRY_CLOSED_VAL) { @@ -1566,10 +1567,11 @@ static void journal_write_done(struct closure *cl) * might want to be written now: */ + spin_unlock(&j->lock); mod_delayed_work(c->io_complete_wq, &j->write_work, max(0L, delta)); + } else { + spin_unlock(&j->lock); } - - spin_unlock(&j->lock); } static void journal_write_endio(struct bio *bio)
