diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2023-07-10 11:17:56 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-22 17:10:06 -0400 |
| commit | 01e691e830edae9a145eeb70f8983223d606e2ca (patch) | |
| tree | 278d45c4b81de206eb65084fda747c7d7a40230d | |
| parent | ba8eeae8eee0aae03eb6be0372519b72057d312c (diff) | |
| download | lwn-01e691e830edae9a145eeb70f8983223d606e2ca.tar.gz lwn-01e691e830edae9a145eeb70f8983223d606e2ca.zip | |
bcachefs: Fix a write buffer flush deadlock
We're not supposed to block if BTREE_INSERT_JOURNAL_RECLAIM && watermark
!= BCH_WATERMARK_reclaim.
This should really be a separate BTREE_INSERT_NONBLOCK flag - add some
comments to that effect, it's not important for this patch.
btree write buffer flush depends on this behaviour though - the first
loop tries to flush sequentially, which doesn't free up space in the
journal optimally. If that can't proceed we bail out and flush in
journal order - that won't work if we're blocked instead of returning an
error.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
| -rw-r--r-- | fs/bcachefs/btree_update_interior.c | 11 | ||||
| -rw-r--r-- | fs/bcachefs/btree_update_leaf.c | 4 |
2 files changed, 15 insertions, 0 deletions
diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c index 5592feff79d1..3659b2c08109 100644 --- a/fs/bcachefs/btree_update_interior.c +++ b/fs/bcachefs/btree_update_interior.c @@ -1158,6 +1158,17 @@ bch2_btree_update_start(struct btree_trans *trans, struct btree_path *path, bch2_err_matches(ret, ENOMEM)) { struct closure cl; + /* + * XXX: this should probably be a separate BTREE_INSERT_NONBLOCK + * flag + */ + if (bch2_err_matches(ret, ENOSPC) && + (flags & BTREE_INSERT_JOURNAL_RECLAIM) && + watermark != BCH_WATERMARK_reclaim) { + ret = -BCH_ERR_journal_reclaim_would_deadlock; + goto err; + } + closure_init_stack(&cl); do { diff --git a/fs/bcachefs/btree_update_leaf.c b/fs/bcachefs/btree_update_leaf.c index 6e12e8e7c301..53219fdcff66 100644 --- a/fs/bcachefs/btree_update_leaf.c +++ b/fs/bcachefs/btree_update_leaf.c @@ -958,6 +958,10 @@ int bch2_trans_commit_error(struct btree_trans *trans, unsigned flags, bch2_replicas_delta_list_mark(c, trans->fs_usage_deltas)); break; case -BCH_ERR_journal_res_get_blocked: + /* + * XXX: this should probably be a separate BTREE_INSERT_NONBLOCK + * flag + */ if ((flags & BTREE_INSERT_JOURNAL_RECLAIM) && (flags & BCH_WATERMARK_MASK) != BCH_WATERMARK_reclaim) { ret = -BCH_ERR_journal_reclaim_would_deadlock; |