diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2022-10-09 11:29:04 +0300 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-23 00:09:42 +0300 |
| commit | 1148a97f1fb9b80ef5355021f0c2dfc7b8f003a2 (patch) | |
| tree | 6acb14dfff4d86d895e01b67aca7428b6abb7723 /fs/bcachefs/btree_locking.c | |
| parent | 1be887979bc12a6c88b33b0d53dfdc369bfa9d49 (diff) | |
| download | linux-1148a97f1fb9b80ef5355021f0c2dfc7b8f003a2.tar.xz | |
bcachefs: Print cycle on unrecoverable deadlock
Some lock operations can't fail; a cycle of nofail locks is impossible
to recover from. So we want to get rid of these nofail locking
operations, but as this is tricky it'll be done incrementally.
If such a cycle happens, this patch prints out which codepaths are
involved so we know what to work on next.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/btree_locking.c')
| -rw-r--r-- | fs/bcachefs/btree_locking.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c index ad6e364980f3..3973e8d7e6da 100644 --- a/fs/bcachefs/btree_locking.c +++ b/fs/bcachefs/btree_locking.c @@ -138,7 +138,29 @@ static noinline int break_cycle(struct lock_graph *g) return abort_lock(g, i); } - BUG(); + { + struct bch_fs *c = g->g->trans->c; + struct printbuf buf = PRINTBUF; + + bch_err(c, "cycle of nofail locks"); + + for (i = g->g; i < g->g + g->nr; i++) { + struct btree_trans *trans = i->trans; + + bch2_btree_trans_to_text(&buf, trans); + + prt_printf(&buf, "backtrace:"); + prt_newline(&buf); + printbuf_indent_add(&buf, 2); + bch2_prt_backtrace(&buf, trans->locking_wait.task); + printbuf_indent_sub(&buf, 2); + prt_newline(&buf); + } + + bch2_print_string_as_lines(KERN_ERR, buf.buf); + printbuf_exit(&buf); + BUG(); + } } static void lock_graph_pop(struct lock_graph *g) |