Commit 290342f6 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David Sterba
Browse files

btrfs: use BUG() instead of BUG_ON(1) 



BUG_ON(1) leads to bogus warnings from clang when
CONFIG_PROFILE_ANNOTATED_BRANCHES is set:

fs/btrfs/volumes.c:5041:3: error: variable 'max_chunk_size' is used uninitialized whenever 'if' condition is false
      [-Werror,-Wsometimes-uninitialized]
                BUG_ON(1);
                ^~~~~~~~~
include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON'
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                   ^~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:48:23: note: expanded from macro 'unlikely'
 #  define unlikely(x)   (__branch_check__(x, 0, __builtin_constant_p(x)))
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/btrfs/volumes.c:5046:9: note: uninitialized use occurs here
                             max_chunk_size);
                             ^~~~~~~~~~~~~~
include/linux/kernel.h:860:36: note: expanded from macro 'min'
 #define min(x, y)       __careful_cmp(x, y, <)
                                         ^
include/linux/kernel.h:853:17: note: expanded from macro '__careful_cmp'
                __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
                              ^
include/linux/kernel.h:847:25: note: expanded from macro '__cmp_once'
                typeof(y) unique_y = (y);               \
                                      ^
fs/btrfs/volumes.c:5041:3: note: remove the 'if' if its condition is always true
                BUG_ON(1);
                ^
include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON'
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                               ^
fs/btrfs/volumes.c:4993:20: note: initialize the variable 'max_chunk_size' to silence this warning
        u64 max_chunk_size;
                          ^
                           = 0

Change it to BUG() so clang can see that this code path can never
continue.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 247462a5

fs/btrfs/backref.c

+2 −2
Original line number Diff line number Diff line
@@ -791,7 +791,7 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info, 
			count = node->ref_mod * -1;

			break;

		default:

			BUG_ON(1);

			BUG();

		}

		*total_refs += count;

		switch (node->type) {
@@ -1747,7 +1747,7 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, 
		else if (flags & BTRFS_EXTENT_FLAG_DATA)

			*flags_ret = BTRFS_EXTENT_FLAG_DATA;

		else

			BUG_ON(1);

			BUG();

		return 0;

	}

fs/btrfs/ctree.c

+2 −2
Original line number Diff line number Diff line
@@ -4684,7 +4684,7 @@ void btrfs_extend_item(struct btrfs_fs_info *fs_info, struct btrfs_path *path, 
		btrfs_print_leaf(leaf);

		btrfs_crit(fs_info, "slot %d too large, nritems %d",

			   slot, nritems);

		BUG_ON(1);

		BUG();

	}



	/*
@@ -4764,7 +4764,7 @@ void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, 
			btrfs_print_leaf(leaf);

			btrfs_crit(fs_info, "slot %d old_data %d data_end %d",

				   slot, old_data, data_end);

			BUG_ON(1);

			BUG();

		}

		/*

		 * item0..itemN ... dataN.offset..dataN.size .. data0.size

fs/btrfs/extent_io.c

+4 −4
Original line number Diff line number Diff line
@@ -5786,13 +5786,13 @@ void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 
		btrfs_err(fs_info,

			"memmove bogus src_offset %lu move len %lu dst len %lu",

			 src_offset, len, dst->len);

		BUG_ON(1);

		BUG();

	}

	if (dst_offset + len > dst->len) {

		btrfs_err(fs_info,

			"memmove bogus dst_offset %lu move len %lu dst len %lu",

			 dst_offset, len, dst->len);

		BUG_ON(1);

		BUG();

	}



	while (len > 0) {
@@ -5833,13 +5833,13 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 
		btrfs_err(fs_info,

			  "memmove bogus src_offset %lu move len %lu len %lu",

			  src_offset, len, dst->len);

		BUG_ON(1);

		BUG();

	}

	if (dst_offset + len > dst->len) {

		btrfs_err(fs_info,

			  "memmove bogus dst_offset %lu move len %lu len %lu",

			  dst_offset, len, dst->len);

		BUG_ON(1);

		BUG();

	}

	if (dst_offset < src_offset) {

		memcpy_extent_buffer(dst, dst_offset, src_offset, len);

fs/btrfs/file.c

+1 −1
Original line number Diff line number Diff line
@@ -1025,7 +1025,7 @@ delete_extent_item: 
			continue;

		}



		BUG_ON(1);

		BUG();

	}



	if (!ret && del_nr > 0) {

fs/btrfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -1451,7 +1451,7 @@ next_slot: 
			extent_end = ALIGN(extent_end,

					   fs_info->sectorsize);

		} else {

			BUG_ON(1);

			BUG();

		}

out_check:

		if (extent_end <= start) {

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