Merge tag 'arm-vfp-refactor-for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux into devel-stabledevel-stable

Refactor VFP support code and reimplement in C

The VFP related changes to permit kernel mode NEON in softirq context
resulted in some issues regarding en/disabling of sofirqs from asm code,
and this made it clear that it would be better to handle more of it from
C code.

Given that we already have infrastructure that associates undefined
instruction exceptions with handler code based on value/mask pairs, we
can easily move the dispatch of VFP and NEON instructions to C code once
we reimplement the actual VFP support routine (which reasons about how
to deal with the exception and whether any emulation is needed) in C
code first.

With those out of the way, we can drop the partial decoding logic in asm
that reasons about which ISA is being used by user space, as the
remaining cases are all 32-bit ARM only. This leaves a FPE specific
routine with some iWMMXT logic that is easily duplicated in C as well,
allowing us to move the FPE asm code into the FPE asm source file, and
out of the shared entry code.

1 files changed, 37 insertions, 1 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 3c983c70028a..2ff2961b1183 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2627,6 +2627,10 @@ static bool check_sibling_keys(struct extent_buffer *left,
 	}
 
 	if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) {
+		btrfs_crit(left->fs_info, "left extent buffer:");
+		btrfs_print_tree(left, false);
+		btrfs_crit(left->fs_info, "right extent buffer:");
+		btrfs_print_tree(right, false);
 		btrfs_crit(left->fs_info,
 "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)",
 			   left_last.objectid, left_last.type,
@@ -3215,6 +3219,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 
 	if (check_sibling_keys(left, right)) {
 		ret = -EUCLEAN;
+		btrfs_abort_transaction(trans, ret);
 		btrfs_tree_unlock(right);
 		free_extent_buffer(right);
 		return ret;
@@ -3433,6 +3438,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 
 	if (check_sibling_keys(left, right)) {
 		ret = -EUCLEAN;
+		btrfs_abort_transaction(trans, ret);
 		goto out;
 	}
 	return __push_leaf_left(trans, path, min_data_size, empty, left,
@@ -4478,10 +4484,12 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
 {
 	struct btrfs_key key;
+	struct btrfs_key orig_key;
 	struct btrfs_disk_key found_key;
 	int ret;
 
 	btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
+	orig_key = key;
 
 	if (key.offset > 0) {
 		key.offset--;
@@ -4498,8 +4506,36 @@ int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
 
 	btrfs_release_path(path);
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-	if (ret < 0)
+	if (ret <= 0)
 		return ret;
+
+	/*
+	 * Previous key not found. Even if we were at slot 0 of the leaf we had
+	 * before releasing the path and calling btrfs_search_slot(), we now may
+	 * be in a slot pointing to the same original key - this can happen if
+	 * after we released the path, one of more items were moved from a
+	 * sibling leaf into the front of the leaf we had due to an insertion
+	 * (see push_leaf_right()).
+	 * If we hit this case and our slot is > 0 and just decrement the slot
+	 * so that the caller does not process the same key again, which may or
+	 * may not break the caller, depending on its logic.
+	 */
+	if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
+		btrfs_item_key(path->nodes[0], &found_key, path->slots[0]);
+		ret = comp_keys(&found_key, &orig_key);
+		if (ret == 0) {
+			if (path->slots[0] > 0) {
+				path->slots[0]--;
+				return 0;
+			}
+			/*
+			 * At slot 0, same key as before, it means orig_key is
+			 * the lowest, leftmost, key in the tree. We're done.
+			 */
+			return 1;
+		}
+	}
+
 	btrfs_item_key(path->nodes[0], &found_key, 0);
 	ret = comp_keys(&found_key, &key);
 	/*