Commit 90f1c19a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Woodhouse
Browse files

Btrfs: [PATCH] extent_map: fix locking for bio completion 



The bio completion handlers can be run in any context, e.g. when using
the old ide driver they run in hardirq context with irqs disabled so
lockdep rightfully warns about using write_lock_irq useage in these
handlers.

This patch switches clear_extent_bit and set_extent_bit to
write_lock_irqsave to fix this problem.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 9433063b

fs/btrfs/extent_map.c

+8 −6
Original line number Diff line number Diff line
@@ -456,6 +456,7 @@ int clear_extent_bit(struct extent_map_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;
@@ -466,7 +467,7 @@ again: 
			return -ENOMEM;

	}



	write_lock_irq(&tree->lock);

	write_lock_irqsave(&tree->lock, flags);

	/*

	 * this search will find the extents that end after

	 * our range starts
@@ -533,7 +534,7 @@ again: 
	goto search_again;



out:

	write_unlock_irq(&tree->lock);

	write_unlock_irqrestore(&tree->lock, flags);

	if (prealloc)

		free_extent_state(prealloc);
@@ -542,7 +543,7 @@ out: 
search_again:

	if (start >= end)

		goto out;

	write_unlock_irq(&tree->lock);

	write_unlock_irqrestore(&tree->lock, flags);

	if (mask & __GFP_WAIT)

		cond_resched();

	goto again;
@@ -628,6 +629,7 @@ int set_extent_bit(struct extent_map_tree *tree, u64 start, u64 end, int bits, 
	struct extent_state *state;

	struct extent_state *prealloc = NULL;

	struct rb_node *node;

	unsigned long flags;

	int err = 0;

	int set;

	u64 last_start;
@@ -639,7 +641,7 @@ again: 
			return -ENOMEM;

	}



	write_lock_irq(&tree->lock);

	write_lock_irqsave(&tree->lock, flags);

	/*

	 * this search will find all the extents that end after

	 * our range starts.
@@ -759,7 +761,7 @@ again: 
	goto search_again;



out:

	write_unlock_irq(&tree->lock);

	write_unlock_irqrestore(&tree->lock, flags);

	if (prealloc)

		free_extent_state(prealloc);
@@ -768,7 +770,7 @@ out: 
search_again:

	if (start > end)

		goto out;

	write_unlock_irq(&tree->lock);

	write_unlock_irqrestore(&tree->lock, flags);

	if (mask & __GFP_WAIT)

		cond_resched();

	goto again;

CRA Git | Maintained and supported by SUSTech CRA and CCSE