From 2ef995df0ce592f665d312008dbe1ad1c4bcf87f Mon Sep 17 00:00:00 2001 From: Jeongjun Park Date: Sun, 2 Feb 2025 15:13:51 +0900 Subject: [PATCH] bcachefs: fix deadlock in journal_entry_open() In the previous commit b3d82c2f2761, code was added to prevent journal sequence overflow. Among them, the code added to journal_entry_open() uses the bch2_fs_fatal_err_on() function to handle errors. However, __journal_res_get() , which calls journal_entry_open() , calls journal_entry_open() while holding journal->lock , but bch2_fs_fatal_err_on() internally tries to acquire journal->lock , which results in a deadlock. So we need to add a locked helper to handle fatal errors even when the journal->lock is held. Fixes: b3d82c2f2761 ("bcachefs: Guard against journal seq overflow") Signed-off-by: Jeongjun Park Signed-off-by: Kent Overstreet --- fs/bcachefs/journal.c | 17 +++++++++++++++-- fs/bcachefs/journal.h | 1 + fs/bcachefs/super.c | 11 +++++++++++ fs/bcachefs/super.h | 1 + 4 files changed, 28 insertions(+), 2 deletions(-) diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c index cb2c3722f6741..0a943a27ef449 100644 --- a/fs/bcachefs/journal.c +++ b/fs/bcachefs/journal.c @@ -319,6 +319,16 @@ void bch2_journal_halt(struct journal *j) spin_unlock(&j->lock); } +void bch2_journal_halt_locked(struct journal *j) +{ + lockdep_assert_held(&j->lock); + + __journal_entry_close(j, JOURNAL_ENTRY_ERROR_VAL, true); + if (!j->err_seq) + j->err_seq = journal_cur_seq(j); + journal_wake(j); +} + static bool journal_entry_want_write(struct journal *j) { bool ret = !journal_entry_is_open(j) || @@ -381,9 +391,12 @@ static int journal_entry_open(struct journal *j) if (nr_unwritten_journal_entries(j) == ARRAY_SIZE(j->buf)) return JOURNAL_ERR_max_in_flight; - if (bch2_fs_fatal_err_on(journal_cur_seq(j) >= JOURNAL_SEQ_MAX, - c, "cannot start: journal seq overflow")) + if (journal_cur_seq(j) >= JOURNAL_SEQ_MAX) { + bch_err(c, "cannot start: journal seq overflow"); + if (bch2_fs_emergency_read_only_locked(c)) + bch_err(c, "fatal error - emergency read only"); return JOURNAL_ERR_insufficient_devices; /* -EROFS */ + } BUG_ON(!j->cur_entry_sectors); diff --git a/fs/bcachefs/journal.h b/fs/bcachefs/journal.h index dccddd5420adf..107f7f901cd96 100644 --- a/fs/bcachefs/journal.h +++ b/fs/bcachefs/journal.h @@ -409,6 +409,7 @@ bool bch2_journal_noflush_seq(struct journal *, u64, u64); int bch2_journal_meta(struct journal *); void bch2_journal_halt(struct journal *); +void bch2_journal_halt_locked(struct journal *); static inline int bch2_journal_error(struct journal *j) { diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c index d97ea7bd1171b..6d97d412fed98 100644 --- a/fs/bcachefs/super.c +++ b/fs/bcachefs/super.c @@ -411,6 +411,17 @@ bool bch2_fs_emergency_read_only(struct bch_fs *c) return ret; } +bool bch2_fs_emergency_read_only_locked(struct bch_fs *c) +{ + bool ret = !test_and_set_bit(BCH_FS_emergency_ro, &c->flags); + + bch2_journal_halt_locked(&c->journal); + bch2_fs_read_only_async(c); + + wake_up(&bch2_read_only_wait); + return ret; +} + static int bch2_fs_read_write_late(struct bch_fs *c) { int ret; diff --git a/fs/bcachefs/super.h b/fs/bcachefs/super.h index fa6d522165108..04f8287eff5c3 100644 --- a/fs/bcachefs/super.h +++ b/fs/bcachefs/super.h @@ -29,6 +29,7 @@ int bch2_dev_resize(struct bch_fs *, struct bch_dev *, u64); struct bch_dev *bch2_dev_lookup(struct bch_fs *, const char *); bool bch2_fs_emergency_read_only(struct bch_fs *); +bool bch2_fs_emergency_read_only_locked(struct bch_fs *); void bch2_fs_read_only(struct bch_fs *); int bch2_fs_read_write(struct bch_fs *); -- 2.39.5