Btrfs: shift all end_io work to thread pools

bio_end_io for reads without checksumming on and btree writes were
happening without using async thread pools.  This means the extent_io.c
code had to use spin_lock_irq and friends on the rb tree locks for
extent state.

There were some irq safe vs unsafe lock inversions between the delallock
lock and the extent state locks.  This patch gets rid of them by moving
all end_io code into the thread pools.

To avoid contention and deadlocks between the data end_io processing and the
metadata end_io processing yet another thread pool is added to finish
off metadata writes.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 24 insertions, 27 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 607f5ff2791c..25ce2d18e5b4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -477,7 +477,6 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 	struct extent_state *state;
 	struct extent_state *prealloc = NULL;
 	struct rb_node *node;
-	unsigned long flags;
 	int err;
 	int set = 0;
 
@@ -488,7 +487,7 @@ again:
 			return -ENOMEM;
 	}
 
-	spin_lock_irqsave(&tree->lock, flags);
+	spin_lock(&tree->lock);
 	/*
 	 * this search will find the extents that end after
 	 * our range starts
@@ -559,7 +558,7 @@ again:
 	goto search_again;
 
 out:
-	spin_unlock_irqrestore(&tree->lock, flags);
+	spin_unlock(&tree->lock);
 	if (prealloc)
 		free_extent_state(prealloc);
 
@@ -568,7 +567,7 @@ out:
 search_again:
 	if (start > end)
 		goto out;
-	spin_unlock_irqrestore(&tree->lock, flags);
+	spin_unlock(&tree->lock);
 	if (mask & __GFP_WAIT)
 		cond_resched();
 	goto again;
@@ -582,9 +581,9 @@ static int wait_on_state(struct extent_io_tree *tree,
 {
 	DEFINE_WAIT(wait);
 	prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE);
-	spin_unlock_irq(&tree->lock);
+	spin_unlock(&tree->lock);
 	schedule();
-	spin_lock_irq(&tree->lock);
+	spin_lock(&tree->lock);
 	finish_wait(&state->wq, &wait);
 	return 0;
 }
@@ -599,7 +598,7 @@ int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
 	struct extent_state *state;
 	struct rb_node *node;
 
-	spin_lock_irq(&tree->lock);
+	spin_lock(&tree->lock);
 again:
 	while (1) {
 		/*
@@ -628,13 +627,13 @@ again:
 			break;
 
 		if (need_resched()) {
-			spin_unlock_irq(&tree->lock);
+			spin_unlock(&tree->lock);
 			cond_resched();
-			spin_lock_irq(&tree->lock);
+			spin_lock(&tree->lock);
 		}
 	}
 out:
-	spin_unlock_irq(&tree->lock);
+	spin_unlock(&tree->lock);
 	return 0;
 }
 EXPORT_SYMBOL(wait_extent_bit);
@@ -668,7 +667,6 @@ static int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int b
 	struct extent_state *state;
 	struct extent_state *prealloc = NULL;
 	struct rb_node *node;
-	unsigned long flags;
 	int err = 0;
 	int set;
 	u64 last_start;
@@ -680,7 +678,7 @@ again:
 			return -ENOMEM;
 	}
 
-	spin_lock_irqsave(&tree->lock, flags);
+	spin_lock(&tree->lock);
 	/*
 	 * this search will find all the extents that end after
 	 * our range starts.
@@ -800,7 +798,7 @@ again:
 	goto search_again;
 
 out:
-	spin_unlock_irqrestore(&tree->lock, flags);
+	spin_unlock(&tree->lock);
 	if (prealloc)
 		free_extent_state(prealloc);
 
@@ -809,7 +807,7 @@ out:
 search_again:
 	if (start > end)
 		goto out;
-	spin_unlock_irqrestore(&tree->lock, flags);
+	spin_unlock(&tree->lock);
 	if (mask & __GFP_WAIT)
 		cond_resched();
 	goto again;
@@ -1021,7 +1019,7 @@ int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
 	struct extent_state *state;
 	int ret = 1;
 
-	spin_lock_irq(&tree->lock);
+	spin_lock(&tree->lock);
 	/*
 	 * this search will find all the extents that end after
 	 * our range starts.
@@ -1044,7 +1042,7 @@ int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
 			break;
 	}
 out:
-	spin_unlock_irq(&tree->lock);
+	spin_unlock(&tree->lock);
 	return ret;
 }
 EXPORT_SYMBOL(find_first_extent_bit);
@@ -1097,7 +1095,7 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
 	u64 found = 0;
 	u64 total_bytes = 0;
 
-	spin_lock_irq(&tree->lock);
+	spin_lock(&tree->lock);
 
 	/*
 	 * this search will find all the extents that end after
@@ -1134,7 +1132,7 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
 			break;
 	}
 out:
-	spin_unlock_irq(&tree->lock);
+	spin_unlock(&tree->lock);
 	return found;
 }
 
@@ -1391,7 +1389,7 @@ u64 count_range_bits(struct extent_io_tree *tree,
 		return 0;
 	}
 
-	spin_lock_irq(&tree->lock);
+	spin_lock(&tree->lock);
 	if (cur_start == 0 && bits == EXTENT_DIRTY) {
 		total_bytes = tree->dirty_bytes;
 		goto out;
@@ -1424,7 +1422,7 @@ u64 count_range_bits(struct extent_io_tree *tree,
 			break;
 	}
 out:
-	spin_unlock_irq(&tree->lock);
+	spin_unlock(&tree->lock);
 	return total_bytes;
 }
 
@@ -1501,7 +1499,7 @@ int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
 	struct extent_state *state;
 	int ret = 0;
 
-	spin_lock_irq(&tree->lock);
+	spin_lock(&tree->lock);
 	/*
 	 * this search will find all the extents that end after
 	 * our range starts.
@@ -1518,7 +1516,7 @@ int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
 	}
 	state->private = private;
 out:
-	spin_unlock_irq(&tree->lock);
+	spin_unlock(&tree->lock);
 	return ret;
 }
 
@@ -1528,7 +1526,7 @@ int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
 	struct extent_state *state;
 	int ret = 0;
 
-	spin_lock_irq(&tree->lock);
+	spin_lock(&tree->lock);
 	/*
 	 * this search will find all the extents that end after
 	 * our range starts.
@@ -1545,7 +1543,7 @@ int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
 	}
 	*private = state->private;
 out:
-	spin_unlock_irq(&tree->lock);
+	spin_unlock(&tree->lock);
 	return ret;
 }
 
@@ -1561,9 +1559,8 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
 	struct extent_state *state = NULL;
 	struct rb_node *node;
 	int bitset = 0;
-	unsigned long flags;
 
-	spin_lock_irqsave(&tree->lock, flags);
+	spin_lock(&tree->lock);
 	node = tree_search(tree, start);
 	while (node && start <= end) {
 		state = rb_entry(node, struct extent_state, rb_node);
@@ -1594,7 +1591,7 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			break;
 		}
 	}
-	spin_unlock_irqrestore(&tree->lock, flags);
+	spin_unlock(&tree->lock);
 	return bitset;
 }
 EXPORT_SYMBOL(test_range_bit);