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| author |   Kent Overstreet <kent.overstreet@linux.dev> | 2025-05-13 12:55:44 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2025-05-14 17:05:19 -0400 |
| commit | 7b6759b1991d427cf9a562b2891b8c3e87a19c76 (patch) | |
| tree | 6ccea7b463257f87df116efd52f029ea19491e99 | |
| parent | bcachefs: Fix broken btree_path lock invariants in next_node() (diff) | |
| download | wireguard-linux-7b6759b1991d427cf9a562b2891b8c3e87a19c76.tar.xz wireguard-linux-7b6759b1991d427cf9a562b2891b8c3e87a19c76.zip | |
bcachefs: Fix livelock in journal_entry_open()
When the journal is low on space, we might do discards from
journal_res_get() -> journal_entry_open().
Make sure we set j->can_discard correctly, so that if we're low on space
but not because discards aren't keeping up we don't livelock.
Fixes: 8e4d28036c29 ("bcachefs: Don't aggressively discard the journal")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
| -rw-r--r-- | fs/bcachefs/journal_reclaim.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/fs/bcachefs/journal_reclaim.c b/fs/bcachefs/journal_reclaim.c index 976464d8a695..cc00b0fc40d8 100644 --- a/fs/bcachefs/journal_reclaim.c +++ b/fs/bcachefs/journal_reclaim.c @@ -17,6 +17,8 @@ #include <linux/kthread.h> #include <linux/sched/mm.h> +static bool __should_discard_bucket(struct journal *, struct journal_device *); + /* Free space calculations: */ static unsigned journal_space_from(struct journal_device *ja, @@ -203,8 +205,7 @@ void bch2_journal_space_available(struct journal *j) ja->bucket_seq[ja->dirty_idx_ondisk] < j->last_seq_ondisk) ja->dirty_idx_ondisk = (ja->dirty_idx_ondisk + 1) % ja->nr; - if (ja->discard_idx != ja->dirty_idx_ondisk) - can_discard = true; + can_discard |= __should_discard_bucket(j, ja); max_entry_size = min_t(unsigned, max_entry_size, ca->mi.bucket_size); nr_online++; @@ -264,13 +265,19 @@ out: /* Discards - last part of journal reclaim: */ -static bool should_discard_bucket(struct journal *j, struct journal_device *ja) +static bool __should_discard_bucket(struct journal *j, struct journal_device *ja) { - spin_lock(&j->lock); unsigned min_free = max(4, ja->nr / 8); - bool ret = bch2_journal_dev_buckets_available(j, ja, journal_space_discarded) < min_free && + return bch2_journal_dev_buckets_available(j, ja, journal_space_discarded) < + min_free && ja->discard_idx != ja->dirty_idx_ondisk; +} + +static bool should_discard_bucket(struct journal *j, struct journal_device *ja) +{ + spin_lock(&j->lock); + bool ret = __should_discard_bucket(j, ja); spin_unlock(&j->lock); return ret; |