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| author | Kent Overstreet <kent.overstreet@gmail.com> | 2022-02-27 17:56:33 +0300 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-23 00:09:26 +0300 |
| commit | bf3efff5e4fc2dcd6e6c15578d3f08c301a13229 (patch) | |
| tree | cca40f2591a81ba52e14350a663266b83c78e43f /fs/bcachefs/btree_cache.c | |
| parent | 6f5f747c318be4adf3824ee7716a7886da35f9a3 (diff) | |
| download | linux-bf3efff5e4fc2dcd6e6c15578d3f08c301a13229.tar.xz | |
bcachefs: Fix race leading to btree node write getting stuck
Checking btree_node_may_write() isn't atomic with the other btree flags,
dirty and need_write in particular. There was a rare race where we'd
unblock a node from writing while __btree_node_flush() was setting
need_write, and no thread would notice that the node was now both able
to write and needed to be written.
Fix this by adding btree node flags for will_make_reachable and
write_blocked that can be checked in the cmpxchg loop in
__bch2_btree_node_write.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Diffstat (limited to 'fs/bcachefs/btree_cache.c')
| -rw-r--r-- | fs/bcachefs/btree_cache.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/bcachefs/btree_cache.c b/fs/bcachefs/btree_cache.c index 7b264619c276..5f96c5d1a064 100644 --- a/fs/bcachefs/btree_cache.c +++ b/fs/bcachefs/btree_cache.c @@ -223,10 +223,9 @@ wait_on_io: goto wait_on_io; } - if (btree_node_noevict(b)) - goto out_unlock; - - if (!btree_node_may_write(b)) + if (btree_node_noevict(b) || + btree_node_write_blocked(b) || + btree_node_will_make_reachable(b)) goto out_unlock; if (btree_node_dirty(b)) { |