btrfs: enhance extent_io_tree error reports

Pass the type of the extent io tree operation which failed in the report
helper. The message wording and contents is updated, though locking
might be the cause of the error it's probably not the only one and we're
interested in the state.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent-io-tree.c

@@ -313,10 +313,14 @@ static inline struct extent_state *tree_search(struct extent_io_tree *tree, u64
 	return tree_search_for_insert(tree, offset, NULL, NULL);
 }
 
-static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
+static void extent_io_tree_panic(const struct extent_io_tree *tree,
+				 const struct extent_state *state,
+				 const char *opname,
+				 int err)
 {
 	btrfs_panic(tree->fs_info, err,
-	"locking error: extent tree was modified by another thread while locked");
+		    "extent io tree error on %s state start %llu end %llu",
+		    opname, state->start, state->end);
 }
 
 static void merge_prev_state(struct extent_io_tree *tree, struct extent_state *state)
@@ -676,7 +680,7 @@ int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			goto search_again;
 		err = split_state(tree, state, prealloc, start);
 		if (err)
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, state, "split", err);
 
 		prealloc = NULL;
 		if (err)
@@ -698,7 +702,7 @@ int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			goto search_again;
 		err = split_state(tree, state, prealloc, end + 1);
 		if (err)
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, state, "split", err);
 
 		if (wake)
 			wake_up(&state->wq);
@@ -1133,7 +1137,7 @@ static int __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			goto search_again;
 		err = split_state(tree, state, prealloc, start);
 		if (err)
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, state, "split", err);
 
 		prealloc = NULL;
 		if (err)
@@ -1181,7 +1185,7 @@ static int __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 		inserted_state = insert_state(tree, prealloc, bits, changeset);
 		if (IS_ERR(inserted_state)) {
 			err = PTR_ERR(inserted_state);
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, prealloc, "insert", err);
 		}
 
 		cache_state(inserted_state, cached_state);
@@ -1209,7 +1213,7 @@ static int __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 			goto search_again;
 		err = split_state(tree, state, prealloc, end + 1);
 		if (err)
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, state, "split", err);
 
 		set_state_bits(tree, prealloc, bits, changeset);
 		cache_state(prealloc, cached_state);
@@ -1363,7 +1367,7 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 		}
 		err = split_state(tree, state, prealloc, start);
 		if (err)
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, state, "split", err);
 		prealloc = NULL;
 		if (err)
 			goto out;
@@ -1411,7 +1415,7 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 		inserted_state = insert_state(tree, prealloc, bits, NULL);
 		if (IS_ERR(inserted_state)) {
 			err = PTR_ERR(inserted_state);
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, prealloc, "insert", err);
 		}
 		cache_state(inserted_state, cached_state);
 		if (inserted_state == prealloc)
@@ -1434,7 +1438,7 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 
 		err = split_state(tree, state, prealloc, end + 1);
 		if (err)
-			extent_io_tree_panic(tree, err);
+			extent_io_tree_panic(tree, state, "split", err);
 
 		set_state_bits(tree, prealloc, bits, NULL);
 		cache_state(prealloc, cached_state);