Merge series "Compatible string consolidation for NXP DSPI driver" from Vladimir Oltean <olteanv@gmail.com>:

This series makes room in the driver for differentiation between the
controllers which currently operate in TCFQ mode. Most of these are
actually capable of a lot more in terms of throughput. This is in
preparation of a second series which will convert the remaining users of
TCFQ mode altogether to XSPI mode with command cycling.

Vladimir Oltean (6):
  doc: spi-fsl-dspi: Add specific compatibles for all Layerscape SoCs
  spi: spi-fsl-dspi: Use specific compatible strings for all SoC
    instantiations
  spi: spi-fsl-dspi: Parameterize the FIFO size and DMA buffer size
  spi: spi-fsl-dspi: LS2080A and LX2160A support XSPI mode
  spi: spi-fsl-dspi: Support SPI software timestamping in all non-DMA
    modes
  spi: spi-fsl-dspi: Convert the instantiations that support it to DMA

 .../devicetree/bindings/spi/spi-fsl-dspi.txt  |  17 +-
 drivers/spi/spi-fsl-dspi.c                    | 162 +++++++++++++-----
 2 files changed, 128 insertions(+), 51 deletions(-)

--
2.17.1

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 6f417ff68980..bd6229fb2b6f 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -237,6 +237,17 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
 	struct extent_map *merge = NULL;
 	struct rb_node *rb;
 
+	/*
+	 * We can't modify an extent map that is in the tree and that is being
+	 * used by another task, as it can cause that other task to see it in
+	 * inconsistent state during the merging. We always have 1 reference for
+	 * the tree and 1 for this task (which is unpinning the extent map or
+	 * clearing the logging flag), so anything > 2 means it's being used by
+	 * other tasks too.
+	 */
+	if (refcount_read(&em->refs) > 2)
+		return;
+
 	if (em->start != 0) {
 		rb = rb_prev(&em->rb_node);
 		if (rb)