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| author | Kent Overstreet <kent.overstreet@linux.dev> | 2022-12-14 20:52:11 -0500 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-22 17:09:52 -0400 |
| commit | 350175bf9b0fe5da12a2fd8bfd453a49f038ceb4 (patch) | |
| tree | 6118c2363f0ee7570b8d9ac6440b13217b8c322e /fs/bcachefs/io.c | |
| parent | f3a37e76cade1469871c4309584ebbc358becf40 (diff) | |
| download | lwn-350175bf9b0fe5da12a2fd8bfd453a49f038ceb4.tar.gz lwn-350175bf9b0fe5da12a2fd8bfd453a49f038ceb4.zip | |
bcachefs: Improved nocow locking
This improves the nocow lock table so that hash table entries have
multiple locks, and locks specify which bucket they're for - i.e. we can
now resolve hash collisions.
This is important because the allocator has to skip buckets that are
locked in the nocow lock table, and previously hash collisions would
cause it to spuriously skip unlocked buckets.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/io.c')
| -rw-r--r-- | fs/bcachefs/io.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/fs/bcachefs/io.c b/fs/bcachefs/io.c index d511bd664953..fe0c4b58e525 100644 --- a/fs/bcachefs/io.c +++ b/fs/bcachefs/io.c @@ -27,6 +27,7 @@ #include "journal.h" #include "keylist.h" #include "move.h" +#include "nocow_locking.h" #include "rebalance.h" #include "subvolume.h" #include "super.h" @@ -1469,7 +1470,7 @@ static void bch2_nocow_write(struct bch_write_op *op) struct { struct bpos b; unsigned gen; - two_state_lock_t *l; + struct nocow_lock_bucket *l; } buckets[BCH_REPLICAS_MAX]; unsigned nr_buckets = 0; u32 snapshot; @@ -1516,7 +1517,8 @@ retry: buckets[nr_buckets].b = PTR_BUCKET_POS(c, ptr); buckets[nr_buckets].gen = ptr->gen; buckets[nr_buckets].l = - bucket_nocow_lock(&c->nocow_locks, buckets[nr_buckets].b); + bucket_nocow_lock(&c->nocow_locks, + bucket_to_u64(buckets[nr_buckets].b)); prefetch(buckets[nr_buckets].l); nr_buckets++; @@ -1538,11 +1540,12 @@ retry: for (i = 0; i < nr_buckets; i++) { struct bch_dev *ca = bch_dev_bkey_exists(c, buckets[i].b.inode); - two_state_lock_t *l = buckets[i].l; + struct nocow_lock_bucket *l = buckets[i].l; bool stale; - if (!bch2_two_state_trylock(l, BUCKET_NOCOW_LOCK_UPDATE)) - __bch2_bucket_nocow_lock(&c->nocow_locks, l, BUCKET_NOCOW_LOCK_UPDATE); + __bch2_bucket_nocow_lock(&c->nocow_locks, l, + bucket_to_u64(buckets[i].b), + BUCKET_NOCOW_LOCK_UPDATE); rcu_read_lock(); stale = gen_after(*bucket_gen(ca, buckets[i].b.offset), buckets[i].gen); @@ -2984,11 +2987,6 @@ void bch2_fs_io_exit(struct bch_fs *c) int bch2_fs_io_init(struct bch_fs *c) { - unsigned i; - - for (i = 0; i < ARRAY_SIZE(c->nocow_locks.l); i++) - two_state_lock_init(&c->nocow_locks.l[i]); - if (bioset_init(&c->bio_read, 1, offsetof(struct bch_read_bio, bio), BIOSET_NEED_BVECS) || bioset_init(&c->bio_read_split, 1, offsetof(struct bch_read_bio, bio), |