Merge tag 'for-5.1-part1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This contains usual mix of new features, core changes and fixes; full
  list below. I'm planning second pull request, with a few more fixes
  that arrived recently but too close to merge window, will send it next
  week.

  New features:

   - support zstd compression levels

   - new ioctl to unregister a device from the module (ie. reverse of
     device scan)

   - scrub prints a message to log when it's about to start or finish

  Core changes:

   - qgroups can now skip part of a tree that does not get updated
     during relocation, because this does not affect the quota
     accounting, estimated speedup in run time is about 20%

   - the compression workspace management had to be enhanced due to zstd
     requirements

   - various enospc fixes, when there's high fragmentation the
     over-reservation can cause ENOSPC that might not happen after a
     flush, in such cases try to wait if the situation improves

  Fixes:

   - various ioctls could overwrite previous return value if
     copy_to_user fails, fix this so the original error is reported

   - more reclaim vs GFP_KERNEL fixes

   - other cleanups and refactoring

   - fix a (valid) lockdep warning in a test when device replace is
     destroying worker threads

   - make qgroup async transaction commit more aggressive, this avoids
     some 'quota limit reached' errors if there are not enough data to
     trigger transaction in order to flush

   - fix deadlock between snapshot deletion and quotas when backref
     walking is called from context that already holds the same locks

   - fsync fixes:
      - fix fsync after succession of renames of different files
      - fix fsync after succession of renames and unlink/rmdir"

* tag 'for-5.1-part1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (92 commits)
  btrfs: Remove unnecessary casts in btrfs_read_root_item
  Btrfs: remove assertion when searching for a key in a node/leaf
  Btrfs: add missing error handling after doing leaf/node binary search
  btrfs: drop the lock on error in btrfs_dev_replace_cancel
  btrfs: ensure that a DUP or RAID1 block group has exactly two stripes
  btrfs: init csum_list before possible free
  Btrfs: remove no longer needed range length checks for deduplication
  Btrfs: fix fsync after succession of renames and unlink/rmdir
  Btrfs: fix fsync after succession of renames of different files
  btrfs: honor path->skip_locking in backref code
  btrfs: qgroup: Make qgroup async transaction commit more aggressive
  btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record
  btrfs: scrub: remove unused nocow worker pointer
  btrfs: scrub: add assertions for worker pointers
  btrfs: scrub: convert scrub_workers_refcnt to refcount_t
  btrfs: scrub: add scrub_lock lockdep check in scrub_workers_get
  btrfs: scrub: fix circular locking dependency warning
  btrfs: fix comment its device list mutex not volume lock
  btrfs: extent_io: Kill the forward declaration of flush_write_bio
  btrfs: Fix grossly misleading argument names in extent io search
  ...

1 files changed, 53 insertions, 55 deletions

diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 1da768e5ef75..82b84e4daad1 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -14,43 +14,58 @@
 
 static void btrfs_assert_tree_read_locked(struct extent_buffer *eb);
 
-/*
- * if we currently have a spinning reader or writer lock
- * (indicated by the rw flag) this will bump the count
- * of blocking holders and drop the spinlock.
- */
-void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw)
+void btrfs_set_lock_blocking_read(struct extent_buffer *eb)
 {
 	/*
-	 * no lock is required.  The lock owner may change if
-	 * we have a read lock, but it won't change to or away
-	 * from us.  If we have the write lock, we are the owner
-	 * and it'll never change.
+	 * No lock is required.  The lock owner may change if we have a read
+	 * lock, but it won't change to or away from us.  If we have the write
+	 * lock, we are the owner and it'll never change.
 	 */
 	if (eb->lock_nested && current->pid == eb->lock_owner)
 		return;
-	if (rw == BTRFS_WRITE_LOCK) {
-		if (atomic_read(&eb->blocking_writers) == 0) {
-			WARN_ON(atomic_read(&eb->spinning_writers) != 1);
-			atomic_dec(&eb->spinning_writers);
-			btrfs_assert_tree_locked(eb);
-			atomic_inc(&eb->blocking_writers);
-			write_unlock(&eb->lock);
-		}
-	} else if (rw == BTRFS_READ_LOCK) {
-		btrfs_assert_tree_read_locked(eb);
-		atomic_inc(&eb->blocking_readers);
-		WARN_ON(atomic_read(&eb->spinning_readers) == 0);
-		atomic_dec(&eb->spinning_readers);
-		read_unlock(&eb->lock);
+	btrfs_assert_tree_read_locked(eb);
+	atomic_inc(&eb->blocking_readers);
+	WARN_ON(atomic_read(&eb->spinning_readers) == 0);
+	atomic_dec(&eb->spinning_readers);
+	read_unlock(&eb->lock);
+}
+
+void btrfs_set_lock_blocking_write(struct extent_buffer *eb)
+{
+	/*
+	 * No lock is required.  The lock owner may change if we have a read
+	 * lock, but it won't change to or away from us.  If we have the write
+	 * lock, we are the owner and it'll never change.
+	 */
+	if (eb->lock_nested && current->pid == eb->lock_owner)
+		return;
+	if (atomic_read(&eb->blocking_writers) == 0) {
+		WARN_ON(atomic_read(&eb->spinning_writers) != 1);
+		atomic_dec(&eb->spinning_writers);
+		btrfs_assert_tree_locked(eb);
+		atomic_inc(&eb->blocking_writers);
+		write_unlock(&eb->lock);
 	}
 }
 
-/*
- * if we currently have a blocking lock, take the spinlock
- * and drop our blocking count
- */
-void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
+void btrfs_clear_lock_blocking_read(struct extent_buffer *eb)
+{
+	/*
+	 * No lock is required.  The lock owner may change if we have a read
+	 * lock, but it won't change to or away from us.  If we have the write
+	 * lock, we are the owner and it'll never change.
+	 */
+	if (eb->lock_nested && current->pid == eb->lock_owner)
+		return;
+	BUG_ON(atomic_read(&eb->blocking_readers) == 0);
+	read_lock(&eb->lock);
+	atomic_inc(&eb->spinning_readers);
+	/* atomic_dec_and_test implies a barrier */
+	if (atomic_dec_and_test(&eb->blocking_readers))
+		cond_wake_up_nomb(&eb->read_lock_wq);
+}
+
+void btrfs_clear_lock_blocking_write(struct extent_buffer *eb)
 {
 	/*
 	 * no lock is required.  The lock owner may change if
@@ -60,23 +75,13 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
 	 */
 	if (eb->lock_nested && current->pid == eb->lock_owner)
 		return;
-
-	if (rw == BTRFS_WRITE_LOCK_BLOCKING) {
-		BUG_ON(atomic_read(&eb->blocking_writers) != 1);
-		write_lock(&eb->lock);
-		WARN_ON(atomic_read(&eb->spinning_writers));
-		atomic_inc(&eb->spinning_writers);
-		/* atomic_dec_and_test implies a barrier */
-		if (atomic_dec_and_test(&eb->blocking_writers))
-			cond_wake_up_nomb(&eb->write_lock_wq);
-	} else if (rw == BTRFS_READ_LOCK_BLOCKING) {
-		BUG_ON(atomic_read(&eb->blocking_readers) == 0);
-		read_lock(&eb->lock);
-		atomic_inc(&eb->spinning_readers);
-		/* atomic_dec_and_test implies a barrier */
-		if (atomic_dec_and_test(&eb->blocking_readers))
-			cond_wake_up_nomb(&eb->read_lock_wq);
-	}
+	BUG_ON(atomic_read(&eb->blocking_writers) != 1);
+	write_lock(&eb->lock);
+	WARN_ON(atomic_read(&eb->spinning_writers));
+	atomic_inc(&eb->spinning_writers);
+	/* atomic_dec_and_test implies a barrier */
+	if (atomic_dec_and_test(&eb->blocking_writers))
+		cond_wake_up_nomb(&eb->write_lock_wq);
 }
 
 /*
@@ -232,16 +237,9 @@ again:
 	wait_event(eb->read_lock_wq, atomic_read(&eb->blocking_readers) == 0);
 	wait_event(eb->write_lock_wq, atomic_read(&eb->blocking_writers) == 0);
 	write_lock(&eb->lock);
-	if (atomic_read(&eb->blocking_readers)) {
+	if (atomic_read(&eb->blocking_readers) ||
+	    atomic_read(&eb->blocking_writers)) {
 		write_unlock(&eb->lock);
-		wait_event(eb->read_lock_wq,
-			   atomic_read(&eb->blocking_readers) == 0);
-		goto again;
-	}
-	if (atomic_read(&eb->blocking_writers)) {
-		write_unlock(&eb->lock);
-		wait_event(eb->write_lock_wq,
-			   atomic_read(&eb->blocking_writers) == 0);
 		goto again;
 	}
 	WARN_ON(atomic_read(&eb->spinning_writers));