Merge branch 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes from Chris Mason:
 "Some fixes from Omar and Dave Sterba for our new free space tree.

  This isn't heavily used yet, but as we move toward making it the new
  default we wanted to nail down an endian bug"

* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: tests: uninline member definitions in free_space_extent
  btrfs: tests: constify free space extent specs
  Btrfs: expand free space tree sanity tests to catch endianness bug
  Btrfs: fix extent buffer bitmap tests on big-endian systems
  Btrfs: catch invalid free space trees
  Btrfs: fix mount -o clear_cache,space_cache=v2
  Btrfs: fix free space tree bitmaps on big-endian systems

Author: torvalds

fs/btrfs/ctree.h

@@ -252,7 +252,8 @@ struct btrfs_super_block {
 #define BTRFS_FEATURE_COMPAT_SAFE_CLEAR		0ULL
 
 #define BTRFS_FEATURE_COMPAT_RO_SUPP			\
-	(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE)
+	(BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE |	\
+	 BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID)
 
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_SET	0ULL
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR	0ULL

fs/btrfs/disk-io.c

@@ -2586,6 +2586,7 @@ int open_ctree(struct super_block *sb,
 	int num_backups_tried = 0;
 	int backup_index = 0;
 	int max_active;
+	int clear_free_space_tree = 0;
 
 	tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
 	chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info, GFP_KERNEL);
@@ -3148,6 +3149,26 @@ int open_ctree(struct super_block *sb,
 	if (sb->s_flags & MS_RDONLY)
 		return 0;
 
+	if (btrfs_test_opt(fs_info, CLEAR_CACHE) &&
+	    btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
+		clear_free_space_tree = 1;
+	} else if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
+		   !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID)) {
+		btrfs_warn(fs_info, "free space tree is invalid");
+		clear_free_space_tree = 1;
+	}
+
+	if (clear_free_space_tree) {
+		btrfs_info(fs_info, "clearing free space tree");
+		ret = btrfs_clear_free_space_tree(fs_info);
+		if (ret) {
+			btrfs_warn(fs_info,
+				   "failed to clear free space tree: %d", ret);
+			close_ctree(tree_root);
+			return ret;
+		}
+	}
+
 	if (btrfs_test_opt(tree_root->fs_info, FREE_SPACE_TREE) &&
 	    !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
 		btrfs_info(fs_info, "creating free space tree");
@@ -3185,18 +3206,6 @@ int open_ctree(struct super_block *sb,
 
 	btrfs_qgroup_rescan_resume(fs_info);
 
-	if (btrfs_test_opt(tree_root->fs_info, CLEAR_CACHE) &&
-	    btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
-		btrfs_info(fs_info, "clearing free space tree");
-		ret = btrfs_clear_free_space_tree(fs_info);
-		if (ret) {
-			btrfs_warn(fs_info,
-				"failed to clear free space tree: %d", ret);
-			close_ctree(tree_root);
-			return ret;
-		}
-	}
-
 	if (!fs_info->uuid_root) {
 		btrfs_info(fs_info, "creating UUID tree");
 		ret = btrfs_create_uuid_tree(fs_info);

fs/btrfs/extent_io.c

@@ -5558,17 +5558,45 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
 	}
 }
 
-/*
- * The extent buffer bitmap operations are done with byte granularity because
- * bitmap items are not guaranteed to be aligned to a word and therefore a
- * single word in a bitmap may straddle two pages in the extent buffer.
- */
-#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
-#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
-#define BITMAP_FIRST_BYTE_MASK(start) \
-	((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
-#define BITMAP_LAST_BYTE_MASK(nbits) \
-	(BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
+void le_bitmap_set(u8 *map, unsigned int start, int len)
+{
+	u8 *p = map + BIT_BYTE(start);
+	const unsigned int size = start + len;
+	int bits_to_set = BITS_PER_BYTE - (start % BITS_PER_BYTE);
+	u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(start);
+
+	while (len - bits_to_set >= 0) {
+		*p |= mask_to_set;
+		len -= bits_to_set;
+		bits_to_set = BITS_PER_BYTE;
+		mask_to_set = ~(u8)0;
+		p++;
+	}
+	if (len) {
+		mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
+		*p |= mask_to_set;
+	}
+}
+
+void le_bitmap_clear(u8 *map, unsigned int start, int len)
+{
+	u8 *p = map + BIT_BYTE(start);
+	const unsigned int size = start + len;
+	int bits_to_clear = BITS_PER_BYTE - (start % BITS_PER_BYTE);
+	u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(start);
+
+	while (len - bits_to_clear >= 0) {
+		*p &= ~mask_to_clear;
+		len -= bits_to_clear;
+		bits_to_clear = BITS_PER_BYTE;
+		mask_to_clear = ~(u8)0;
+		p++;
+	}
+	if (len) {
+		mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
+		*p &= ~mask_to_clear;
+	}
+}
 
 /*
  * eb_bitmap_offset() - calculate the page and offset of the byte containing the
@@ -5612,7 +5640,7 @@ static inline void eb_bitmap_offset(struct extent_buffer *eb,
 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
 			   unsigned long nr)
 {
-	char *kaddr;
+	u8 *kaddr;
 	struct page *page;
 	unsigned long i;
 	size_t offset;
@@ -5634,13 +5662,13 @@ int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
 			      unsigned long pos, unsigned long len)
 {
-	char *kaddr;
+	u8 *kaddr;
 	struct page *page;
 	unsigned long i;
 	size_t offset;
 	const unsigned int size = pos + len;
 	int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
-	unsigned int mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
+	u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
 
 	eb_bitmap_offset(eb, start, pos, &i, &offset);
 	page = eb->pages[i];
@@ -5651,7 +5679,7 @@ void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
 		kaddr[offset] |= mask_to_set;
 		len -= bits_to_set;
 		bits_to_set = BITS_PER_BYTE;
-		mask_to_set = ~0U;
+		mask_to_set = ~(u8)0;
 		if (++offset >= PAGE_SIZE && len > 0) {
 			offset = 0;
 			page = eb->pages[++i];
@@ -5676,13 +5704,13 @@ void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
 				unsigned long pos, unsigned long len)
 {
-	char *kaddr;
+	u8 *kaddr;
 	struct page *page;
 	unsigned long i;
 	size_t offset;
 	const unsigned int size = pos + len;
 	int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
-	unsigned int mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
+	u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
 
 	eb_bitmap_offset(eb, start, pos, &i, &offset);
 	page = eb->pages[i];
@@ -5693,7 +5721,7 @@ void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
 		kaddr[offset] &= ~mask_to_clear;
 		len -= bits_to_clear;
 		bits_to_clear = BITS_PER_BYTE;
-		mask_to_clear = ~0U;
+		mask_to_clear = ~(u8)0;
 		if (++offset >= PAGE_SIZE && len > 0) {
 			offset = 0;
 			page = eb->pages[++i];

fs/btrfs/extent_io.h

@@ -59,6 +59,28 @@
  */
 #define EXTENT_PAGE_PRIVATE 1
 
+/*
+ * The extent buffer bitmap operations are done with byte granularity instead of
+ * word granularity for two reasons:
+ * 1. The bitmaps must be little-endian on disk.
+ * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
+ *    single word in a bitmap may straddle two pages in the extent buffer.
+ */
+#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
+#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
+#define BITMAP_FIRST_BYTE_MASK(start) \
+	((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
+#define BITMAP_LAST_BYTE_MASK(nbits) \
+	(BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
+
+static inline int le_test_bit(int nr, const u8 *addr)
+{
+	return 1U & (addr[BIT_BYTE(nr)] >> (nr & (BITS_PER_BYTE-1)));
+}
+
+extern void le_bitmap_set(u8 *map, unsigned int start, int len);
+extern void le_bitmap_clear(u8 *map, unsigned int start, int len);
+
 struct extent_state;
 struct btrfs_root;
 struct btrfs_io_bio;

fs/btrfs/free-space-tree.c

@@ -151,7 +151,7 @@ static inline u32 free_space_bitmap_size(u64 size, u32 sectorsize)
 	return DIV_ROUND_UP((u32)div_u64(size, sectorsize), BITS_PER_BYTE);
 }
 
-static unsigned long *alloc_bitmap(u32 bitmap_size)
+static u8 *alloc_bitmap(u32 bitmap_size)
 {
 	void *mem;
 
@@ -180,8 +180,7 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
 	struct btrfs_free_space_info *info;
 	struct btrfs_key key, found_key;
 	struct extent_buffer *leaf;
-	unsigned long *bitmap;
-	char *bitmap_cursor;
+	u8 *bitmap, *bitmap_cursor;
 	u64 start, end;
 	u64 bitmap_range, i;
 	u32 bitmap_size, flags, expected_extent_count;
@@ -231,7 +230,7 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
 						block_group->sectorsize);
 				last = div_u64(found_key.objectid + found_key.offset - start,
 					       block_group->sectorsize);
-				bitmap_set(bitmap, first, last - first);
+				le_bitmap_set(bitmap, first, last - first);
 
 				extent_count++;
 				nr++;
@@ -270,7 +269,7 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 
-	bitmap_cursor = (char *)bitmap;
+	bitmap_cursor = bitmap;
 	bitmap_range = block_group->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS;
 	i = start;
 	while (i < end) {
@@ -319,7 +318,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
 	struct btrfs_free_space_info *info;
 	struct btrfs_key key, found_key;
 	struct extent_buffer *leaf;
-	unsigned long *bitmap;
+	u8 *bitmap;
 	u64 start, end;
 	/* Initialize to silence GCC. */
 	u64 extent_start = 0;
@@ -363,7 +362,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
 				break;
 			} else if (found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) {
 				unsigned long ptr;
-				char *bitmap_cursor;
+				u8 *bitmap_cursor;
 				u32 bitmap_pos, data_size;
 
 				ASSERT(found_key.objectid >= start);
@@ -373,7 +372,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
 				bitmap_pos = div_u64(found_key.objectid - start,
 						     block_group->sectorsize *
 						     BITS_PER_BYTE);
-				bitmap_cursor = ((char *)bitmap) + bitmap_pos;
+				bitmap_cursor = bitmap + bitmap_pos;
 				data_size = free_space_bitmap_size(found_key.offset,
 								   block_group->sectorsize);
 
@@ -410,7 +409,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
 	offset = start;
 	bitnr = 0;
 	while (offset < end) {
-		bit = !!test_bit(bitnr, bitmap);
+		bit = !!le_test_bit(bitnr, bitmap);
 		if (prev_bit == 0 && bit == 1) {
 			extent_start = offset;
 		} else if (prev_bit == 1 && bit == 0) {
@@ -1185,6 +1184,7 @@ int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info)
 	}
 
 	btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE);
+	btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID);
 	clear_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags);
 
 	ret = btrfs_commit_transaction(trans, tree_root);
@@ -1253,6 +1253,7 @@ int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info)
 		return PTR_ERR(trans);
 
 	btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE);
+	btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID);
 	fs_info->free_space_root = NULL;
 
 	ret = clear_free_space_tree(trans, free_space_root);