btrfs: move simple extent bit helpers out of extent_io.c

These are just variants and wrappers around the actual work horses of
the extent state.  Extract these out of extent_io.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c
index 2aedac452636..4688f67fd8e6 100644
--- a/fs/btrfs/extent-io-tree.c
+++ b/fs/btrfs/extent-io-tree.c
@@ -142,6 +142,51 @@ void free_extent_state(struct extent_state *state)
 	}
 }
 
+/* Wrappers around set/clear extent bit */
+int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+			   u32 bits, struct extent_changeset *changeset)
+{
+	/*
+	 * We don't support EXTENT_LOCKED yet, as current changeset will
+	 * record any bits changed, so for EXTENT_LOCKED case, it will
+	 * either fail with -EEXIST or changeset will record the whole
+	 * range.
+	 */
+	ASSERT(!(bits & EXTENT_LOCKED));
+
+	return set_extent_bit(tree, start, end, bits, 0, NULL, NULL, GFP_NOFS,
+			      changeset);
+}
+
+int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
+			     u32 bits, struct extent_changeset *changeset)
+{
+	/*
+	 * Don't support EXTENT_LOCKED case, same reason as
+	 * set_record_extent_bits().
+	 */
+	ASSERT(!(bits & EXTENT_LOCKED));
+
+	return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, GFP_NOFS,
+				  changeset);
+}
+
+int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
+{
+	int err;
+	u64 failed_start;
+
+	err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
+			     &failed_start, NULL, GFP_NOFS, NULL);
+	if (err == -EEXIST) {
+		if (failed_start > start)
+			clear_extent_bit(tree, start, failed_start - 1,
+					 EXTENT_LOCKED, 1, 0, NULL);
+		return 0;
+	}
+	return 1;
+}
+
 void __cold extent_state_free_cachep(void)
 {
 	btrfs_extent_state_leak_debug_check();