btrfs: remove extent_map::block_start member

The member extent_map::block_start can be calculated from
extent_map::disk_bytenr + extent_map::offset for regular extents.
And otherwise just extent_map::disk_bytenr.

And this is already validated by the validate_extent_map().  Now we can
remove the member.

However there is a special case in btrfs_create_dio_extent() where we
for NOCOW/PREALLOC ordered extents cannot directly use the resulting
btrfs_file_extent, as btrfs_split_ordered_extent() cannot handle them
yet.

So for that call site, we pass file_extent->disk_bytenr +
file_extent->num_bytes as disk_bytenr for the ordered extent, and 0 for
offset.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 17 insertions, 31 deletions

diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c
index 0dd270d6c506..ebec4ab361b8 100644
--- a/fs/btrfs/tests/extent-map-tests.c
+++ b/fs/btrfs/tests/extent-map-tests.c
@@ -28,8 +28,8 @@ static int free_extent_map_tree(struct btrfs_inode *inode)
 		if (refcount_read(&em->refs) != 1) {
 			ret = -EINVAL;
 			test_err(
-"em leak: em (start %llu len %llu block_start %llu disk_num_bytes %llu offset %llu) refs %d",
-				 em->start, em->len, em->block_start,
+"em leak: em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu offset %llu) refs %d",
+				 em->start, em->len, em->disk_bytenr,
 				 em->disk_num_bytes, em->offset,
 				 refcount_read(&em->refs));
 
@@ -77,7 +77,6 @@ static int test_case_1(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 	/* Add [0, 16K) */
 	em->start = 0;
 	em->len = SZ_16K;
-	em->block_start = 0;
 	em->disk_bytenr = 0;
 	em->disk_num_bytes = SZ_16K;
 	em->ram_bytes = SZ_16K;
@@ -100,7 +99,6 @@ static int test_case_1(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 
 	em->start = SZ_16K;
 	em->len = SZ_4K;
-	em->block_start = SZ_32K; /* avoid merging */
 	em->disk_bytenr = SZ_32K; /* avoid merging */
 	em->disk_num_bytes = SZ_4K;
 	em->ram_bytes = SZ_4K;
@@ -123,7 +121,6 @@ static int test_case_1(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 	/* Add [0, 8K), should return [0, 16K) instead. */
 	em->start = start;
 	em->len = len;
-	em->block_start = start;
 	em->disk_bytenr = start;
 	em->disk_num_bytes = len;
 	em->ram_bytes = len;
@@ -141,11 +138,11 @@ static int test_case_1(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 		goto out;
 	}
 	if (em->start != 0 || extent_map_end(em) != SZ_16K ||
-	    em->block_start != 0 || em->disk_num_bytes != SZ_16K) {
+	    em->disk_bytenr != 0 || em->disk_num_bytes != SZ_16K) {
 		test_err(
-"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu disk_num_bytes %llu",
+"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu",
 			 start, start + len, ret, em->start, em->len,
-			 em->block_start, em->disk_num_bytes);
+			 em->disk_bytenr, em->disk_num_bytes);
 		ret = -EINVAL;
 	}
 	free_extent_map(em);
@@ -179,7 +176,6 @@ static int test_case_2(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 	/* Add [0, 1K) */
 	em->start = 0;
 	em->len = SZ_1K;
-	em->block_start = EXTENT_MAP_INLINE;
 	em->disk_bytenr = EXTENT_MAP_INLINE;
 	em->disk_num_bytes = 0;
 	em->ram_bytes = SZ_1K;
@@ -202,7 +198,6 @@ static int test_case_2(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 
 	em->start = SZ_4K;
 	em->len = SZ_4K;
-	em->block_start = SZ_4K;
 	em->disk_bytenr = SZ_4K;
 	em->disk_num_bytes = SZ_4K;
 	em->ram_bytes = SZ_4K;
@@ -225,7 +220,6 @@ static int test_case_2(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 	/* Add [0, 1K) */
 	em->start = 0;
 	em->len = SZ_1K;
-	em->block_start = EXTENT_MAP_INLINE;
 	em->disk_bytenr = EXTENT_MAP_INLINE;
 	em->disk_num_bytes = 0;
 	em->ram_bytes = SZ_1K;
@@ -242,10 +236,10 @@ static int test_case_2(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 		goto out;
 	}
 	if (em->start != 0 || extent_map_end(em) != SZ_1K ||
-	    em->block_start != EXTENT_MAP_INLINE) {
+	    em->disk_bytenr != EXTENT_MAP_INLINE) {
 		test_err(
-"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu",
-			 ret, em->start, em->len, em->block_start);
+"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu disk_bytenr %llu",
+			 ret, em->start, em->len, em->disk_bytenr);
 		ret = -EINVAL;
 	}
 	free_extent_map(em);
@@ -275,7 +269,6 @@ static int __test_case_3(struct btrfs_fs_info *fs_info,
 	/* Add [4K, 8K) */
 	em->start = SZ_4K;
 	em->len = SZ_4K;
-	em->block_start = SZ_4K;
 	em->disk_bytenr = SZ_4K;
 	em->disk_num_bytes = SZ_4K;
 	em->ram_bytes = SZ_4K;
@@ -298,7 +291,6 @@ static int __test_case_3(struct btrfs_fs_info *fs_info,
 	/* Add [0, 16K) */
 	em->start = 0;
 	em->len = SZ_16K;
-	em->block_start = 0;
 	em->disk_bytenr = 0;
 	em->disk_num_bytes = SZ_16K;
 	em->ram_bytes = SZ_16K;
@@ -321,11 +313,11 @@ static int __test_case_3(struct btrfs_fs_info *fs_info,
 	 * em->start.
 	 */
 	if (start < em->start || start + len > extent_map_end(em) ||
-	    em->start != em->block_start) {
+	    em->start != extent_map_block_start(em)) {
 		test_err(
-"case3 [%llu %llu): ret %d em (start %llu len %llu block_start %llu block_len %llu)",
+"case3 [%llu %llu): ret %d em (start %llu len %llu disk_bytenr %llu block_len %llu)",
 			 start, start + len, ret, em->start, em->len,
-			 em->block_start, em->disk_num_bytes);
+			 em->disk_bytenr, em->disk_num_bytes);
 		ret = -EINVAL;
 	}
 	free_extent_map(em);
@@ -386,7 +378,6 @@ static int __test_case_4(struct btrfs_fs_info *fs_info,
 	/* Add [0K, 8K) */
 	em->start = 0;
 	em->len = SZ_8K;
-	em->block_start = 0;
 	em->disk_bytenr = 0;
 	em->disk_num_bytes = SZ_8K;
 	em->ram_bytes = SZ_8K;
@@ -409,7 +400,6 @@ static int __test_case_4(struct btrfs_fs_info *fs_info,
 	/* Add [8K, 32K) */
 	em->start = SZ_8K;
 	em->len = 24 * SZ_1K;
-	em->block_start = SZ_16K; /* avoid merging */
 	em->disk_bytenr = SZ_16K; /* avoid merging */
 	em->disk_num_bytes = 24 * SZ_1K;
 	em->ram_bytes = 24 * SZ_1K;
@@ -431,7 +421,6 @@ static int __test_case_4(struct btrfs_fs_info *fs_info,
 	/* Add [0K, 32K) */
 	em->start = 0;
 	em->len = SZ_32K;
-	em->block_start = 0;
 	em->disk_bytenr = 0;
 	em->disk_num_bytes = SZ_32K;
 	em->ram_bytes = SZ_32K;
@@ -451,9 +440,9 @@ static int __test_case_4(struct btrfs_fs_info *fs_info,
 	}
 	if (start < em->start || start + len > extent_map_end(em)) {
 		test_err(
-"case4 [%llu %llu): ret %d, added wrong em (start %llu len %llu block_start %llu disk_num_bytes %llu)",
-			 start, start + len, ret, em->start, em->len, em->block_start,
-			 em->disk_num_bytes);
+"case4 [%llu %llu): ret %d, added wrong em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu)",
+			 start, start + len, ret, em->start, em->len,
+			 em->disk_bytenr, em->disk_num_bytes);
 		ret = -EINVAL;
 	}
 	free_extent_map(em);
@@ -517,7 +506,6 @@ static int add_compressed_extent(struct btrfs_inode *inode,
 
 	em->start = start;
 	em->len = len;
-	em->block_start = block_start;
 	em->disk_bytenr = block_start;
 	em->disk_num_bytes = SZ_4K;
 	em->ram_bytes = len;
@@ -740,7 +728,6 @@ static int test_case_6(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 
 	em->start = SZ_4K;
 	em->len = SZ_4K;
-	em->block_start = SZ_16K;
 	em->disk_bytenr = SZ_16K;
 	em->disk_num_bytes = SZ_16K;
 	em->ram_bytes = SZ_16K;
@@ -795,7 +782,6 @@ static int test_case_7(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 	/* [0, 16K), pinned */
 	em->start = 0;
 	em->len = SZ_16K;
-	em->block_start = 0;
 	em->disk_bytenr = 0;
 	em->disk_num_bytes = SZ_4K;
 	em->ram_bytes = SZ_16K;
@@ -819,7 +805,6 @@ static int test_case_7(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 	/* [32K, 48K), not pinned */
 	em->start = SZ_32K;
 	em->len = SZ_16K;
-	em->block_start = SZ_32K;
 	em->disk_bytenr = SZ_32K;
 	em->disk_num_bytes = SZ_16K;
 	em->ram_bytes = SZ_16K;
@@ -885,8 +870,9 @@ static int test_case_7(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
 		goto out;
 	}
 
-	if (em->block_start != SZ_32K + SZ_4K) {
-		test_err("em->block_start is %llu, expected 36K", em->block_start);
+	if (extent_map_block_start(em) != SZ_32K + SZ_4K) {
+		test_err("em->block_start is %llu, expected 36K",
+				extent_map_block_start(em));
 		goto out;
 	}