From 76966dbfa9eb4a723cb899ba07f55448e5b21bbe Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sat, 11 Feb 2023 16:53:59 -0500 Subject: [PATCH] bcachefs: Improve locking in __bch2_set_nr_journal_buckets() This refactors to not call bch2_journal_block() with c->sb_lock held. Signed-off-by: Kent Overstreet --- fs/bcachefs/journal.c | 46 +++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 24 deletions(-) diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c index 66bd0a72c7747..00e806a642472 100644 --- a/fs/bcachefs/journal.c +++ b/fs/bcachefs/journal.c @@ -768,6 +768,7 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr, if (c) { bch2_journal_flush_all_pins(&c->journal); bch2_journal_block(&c->journal); + mutex_lock(&c->sb_lock); } bu = kcalloc(nr_want, sizeof(*bu), GFP_KERNEL); @@ -848,6 +849,9 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr, if (!new_fs) spin_unlock(&c->journal.lock); + if (ja->nr != old_nr && !new_fs) + bch2_write_super(c); + if (c) bch2_journal_unblock(&c->journal); @@ -867,6 +871,9 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr, } } err: + if (c) + mutex_unlock(&c->sb_lock); + if (ob && !new_fs) for (i = 0; i < nr_got; i++) bch2_open_bucket_put(c, ob[i]); @@ -892,7 +899,6 @@ int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca, { struct journal_device *ja = &ca->journal; struct closure cl; - unsigned current_nr; int ret = 0; /* don't handle reducing nr of buckets yet: */ @@ -901,44 +907,44 @@ int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca, closure_init_stack(&cl); - while (ja->nr != nr && (ret == 0 || ret == -BCH_ERR_bucket_alloc_blocked)) { + while (ja->nr != nr) { struct disk_reservation disk_res = { 0, 0 }; - closure_sync(&cl); - - mutex_lock(&c->sb_lock); - current_nr = ja->nr; - /* * note: journal buckets aren't really counted as _sectors_ used yet, so * we don't need the disk reservation to avoid the BUG_ON() in buckets.c * when space used goes up without a reservation - but we do need the * reservation to ensure we'll actually be able to allocate: + * + * XXX: that's not right, disk reservations only ensure a + * filesystem-wide allocation will succeed, this is a device + * specific allocation - we can hang here: */ ret = bch2_disk_reservation_get(c, &disk_res, bucket_to_sector(ca, nr - ja->nr), 1, 0); - if (ret) { - mutex_unlock(&c->sb_lock); - return ret; - } + if (ret) + break; ret = __bch2_set_nr_journal_buckets(ca, nr, false, &cl); bch2_disk_reservation_put(c, &disk_res); - if (ja->nr != current_nr) - bch2_write_super(c); - mutex_unlock(&c->sb_lock); + closure_sync(&cl); + + if (ret && ret != -BCH_ERR_bucket_alloc_blocked) + break; } + if (ret) + bch_err(c, "%s: err %s", __func__, bch2_err_str(ret)); + return ret; } int bch2_dev_journal_alloc(struct bch_dev *ca) { unsigned nr; - int ret; if (dynamic_fault("bcachefs:add:journal_alloc")) return -ENOMEM; @@ -955,15 +961,7 @@ int bch2_dev_journal_alloc(struct bch_dev *ca) min(1 << 13, (1 << 24) / ca->mi.bucket_size)); - if (ca->fs) - mutex_lock(&ca->fs->sb_lock); - - ret = __bch2_set_nr_journal_buckets(ca, nr, true, NULL); - - if (ca->fs) - mutex_unlock(&ca->fs->sb_lock); - - return ret; + return __bch2_set_nr_journal_buckets(ca, nr, true, NULL); } /* startup/shutdown: */ -- 2.30.2