Merge tag 'bcachefs-2023-11-17' of https://evilpiepirate.org/git/bcachefs

Pull bcachefs fixes from Kent Overstreet:
 "Lots of small fixes for minor nits and compiler warnings.

  Bigger items:

   - The six locks lost wakeup is finally fixed: six_read_trylock() was
     checking for the waiting bit before decrementing the number of
     readers - validated the fix with a torture test.

   - Fix for a memory reclaim issue: when needing to reallocate a key
     cache key, we now do our usual GFP_NOWAIT; unlock(); GFP_KERNEL
     dance.

   - Multiple deleted inodes btree fixes

   - Fix an issue in fsck, where i_nlink would be recalculated
     incorrectly for hardlinked files if a snapshot had ever been taken.

   - Kill journal pre-reservations: This is a bigger patch than I would
     normally send at this point, but it deletes code and it fixes some
     of our tests that would sporadically die with the journal getting
     stuck, and it's a performance improvement, too"

* tag 'bcachefs-2023-11-17' of https://evilpiepirate.org/git/bcachefs: (22 commits)
  bcachefs: Fix missing locking for dentry->d_parent access
  bcachefs: six locks: Fix lost wakeup
  bcachefs: Fix no_data_io mode checksum check
  bcachefs: Fix bch2_check_nlinks() for snapshots
  bcachefs: Don't decrease BTREE_ITER_MAX when LOCKDEP=y
  bcachefs: Disable debug log statements
  bcachefs: Fix missing transaction commit
  bcachefs: Fix error path in bch2_mount()
  bcachefs: Fix potential sleeping during mount
  bcachefs: Fix iterator leak in may_delete_deleted_inode()
  bcachefs: Kill journal pre-reservations
  bcachefs: Check for nonce offset inconsistency in data_update path
  bcachefs: Make sure to drop/retake btree locks before reclaim
  bcachefs: btree_trans->write_locked
  bcachefs: Run btree key cache shrinker less aggressively
  bcachefs: Split out btree_key_cache_types.h
  bcachefs: Guard against insufficient devices to create stripes
  bcachefs: Fix null ptr deref in bch2_backpointer_get_node()
  bcachefs: Fix multiple -Warray-bounds warnings
  bcachefs: Use DECLARE_FLEX_ARRAY() helper and fix multiple -Warray-bounds warnings
  ...

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/bcachefs/six.c b/fs/bcachefs/six.c
index b775cf0fb7cb..97790445e67a 100644
--- a/fs/bcachefs/six.c
+++ b/fs/bcachefs/six.c
@@ -163,8 +163,11 @@ static int __do_six_trylock(struct six_lock *lock, enum six_lock_type type,
 		this_cpu_sub(*lock->readers, !ret);
 		preempt_enable();
 
-		if (!ret && (old & SIX_LOCK_WAITING_write))
-			ret = -1 - SIX_LOCK_write;
+		if (!ret) {
+			smp_mb();
+			if (atomic_read(&lock->state) & SIX_LOCK_WAITING_write)
+				ret = -1 - SIX_LOCK_write;
+		}
 	} else if (type == SIX_LOCK_write && lock->readers) {
 		if (try) {
 			atomic_add(SIX_LOCK_HELD_write, &lock->state);