btrfs-progs: replace write_and_map_eb() by write_data_to_disk()

The function write_and_map_eb() is quite abused as a way to write any
generic buffer back to disk.

But we have a more suitable function already, write_data_to_disk().

This patch would remove the abused write_data_to_disk() calls, and
convert the only three valid call sites to write_data_to_disk() instead.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: adam900710

btrfs-corrupt-block.c

@@ -38,40 +38,46 @@
 
 #define FIELD_BUF_LEN 80
 
-static int debug_corrupt_block(struct extent_buffer *eb,
-		struct btrfs_root *root, u64 bytenr, u32 blocksize, u64 copy)
+static int debug_corrupt_sector(struct btrfs_root *root, u64 logical, int mirror)
 {
+	const u32 sectorsize = root->fs_info->sectorsize;
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	int ret;
 	int num_copies;
 	int mirror_num = 1;
+	void *buf;
+
+	buf = malloc(root->fs_info->sectorsize);
+	if (!buf) {
+		error_msg(ERROR_MSG_MEMORY, "allocating memory for bytenr %llu",
+			  logical);
+		return -ENOMEM;
+	}
 
 	while (1) {
-		if (!copy || mirror_num == copy) {
-			u64 read_len = eb->len;
+		if (!mirror || mirror_num == mirror) {
+			u64 read_len = sectorsize;
 
-			ret = read_data_from_disk(eb->fs_info, eb->data,
-						  eb->start, &read_len,
-						  mirror_num);
-			if (read_len < eb->len)
+			ret = read_data_from_disk(fs_info, buf, logical,
+						  &read_len, mirror_num);
+			if (read_len < sectorsize)
 				ret = -EIO;
 			if (ret < 0) {
 				errno = -ret;
-				error("cannot read eb bytenr %llu: %m", eb->start);
+				error("cannot read bytenr %llu: %m", logical);
 				return ret;
 			}
-			printf("corrupting %llu copy %d\n", eb->start,
-			       mirror_num);
-			memset(eb->data, 0, eb->len);
-			ret = write_and_map_eb(eb->fs_info, eb);
+			printf("corrupting %llu copy %d\n", logical, mirror_num);
+			memset(buf, 0, sectorsize);
+			ret = write_data_to_disk(fs_info, buf, logical, sectorsize);
 			if (ret < 0) {
 				errno = -ret;
-				error("cannot write eb bytenr %llu: %m", eb->start);
+				error("cannot write bytenr %llu: %m", logical);
 				return ret;
 			}
 		}
 
-		num_copies = btrfs_num_copies(root->fs_info, eb->start,
-					      eb->len);
+		num_copies = btrfs_num_copies(root->fs_info, logical, sectorsize);
 		if (num_copies == 1)
 			break;
 
@@ -157,7 +163,7 @@ static void corrupt_keys(struct btrfs_trans_handle *trans,
 		u16 csum_type = fs_info->csum_type;
 
 		csum_tree_block_size(eb, csum_size, 0, csum_type);
-		write_and_map_eb(eb->fs_info, eb);
+		write_data_to_disk(eb->fs_info, eb->data, eb->start, eb->len);
 	}
 }
 
@@ -878,7 +884,7 @@ static int corrupt_metadata_block(struct btrfs_fs_info *fs_info, u64 block,
 		btrfs_set_header_generation(eb, bogus);
 		csum_tree_block_size(eb, fs_info->csum_size, 0,
 				     fs_info->csum_type);
-		ret = write_and_map_eb(fs_info, eb);
+		ret = write_data_to_disk(fs_info, eb->data, eb->start, eb->len);
 		free_extent_buffer(eb);
 		if (ret < 0) {
 			errno = -ret;
@@ -1607,8 +1613,11 @@ int main(int argc, char **argv)
 				goto out_close;
 			}
 
-			debug_corrupt_block(eb, root, logical,
-					    root->fs_info->sectorsize, copy);
+			ret = debug_corrupt_sector(root, logical, (int)copy);
+			if (ret < 0) {
+				ret = 1;
+				goto out_close;
+			}
 			free_extent_buffer(eb);
 		}
 		logical += root->fs_info->sectorsize;

convert/main.c

@@ -359,7 +359,6 @@ static int migrate_one_reserved_range(struct btrfs_trans_handle *trans,
 	u64 hole_len;
 	struct cache_extent *cache;
 	struct btrfs_key key;
-	struct extent_buffer *eb;
 	int ret = 0;
 
 	/*
@@ -370,6 +369,8 @@ static int migrate_one_reserved_range(struct btrfs_trans_handle *trans,
 	 * migrate ranges that covered by old fs data.
 	 */
 	while (cur_off < range_end(range)) {
+		void *buf;
+
 		cache = search_cache_extent(used, cur_off);
 		if (!cache)
 			break;
@@ -391,25 +392,20 @@ static int migrate_one_reserved_range(struct btrfs_trans_handle *trans,
 		if (ret < 0)
 			break;
 
-		eb = malloc(sizeof(*eb) + cur_len);
-		if (!eb) {
+		buf = malloc(cur_len);
+		if (!buf) {
 			ret = -ENOMEM;
 			break;
 		}
 
-		ret = pread(fd, eb->data, cur_len, cur_off);
+		ret = pread(fd, buf, cur_len, cur_off);
 		if (ret < cur_len) {
 			ret = (ret < 0 ? ret : -EIO);
-			free(eb);
+			free(buf);
 			break;
 		}
-		eb->start = key.objectid;
-		eb->len = key.offset;
-		eb->fs_info = root->fs_info;
-
-		/* Write the data */
-		ret = write_and_map_eb(root->fs_info, eb);
-		free(eb);
+		ret = write_data_to_disk(root->fs_info, buf, key.objectid, key.offset);
+		free(buf);
 		if (ret < 0)
 			break;
 

convert/source-reiserfs.c

@@ -352,22 +352,14 @@ static int convert_direct(struct btrfs_trans_handle *trans,
 	struct btrfs_key key;
 	u32 sectorsize = root->fs_info->sectorsize;
 	int ret;
-	struct extent_buffer *eb;
 
 	BUG_ON(length > sectorsize);
 	ret = btrfs_reserve_extent(trans, root, sectorsize,
 				   0, 0, -1ULL, &key, 1);
 	if (ret)
 		return ret;
 
-	eb = alloc_extent_buffer(root->fs_info, key.objectid, sectorsize);
-
-	if (!eb)
-		return -ENOMEM;
-
-	write_extent_buffer(eb, body, 0, length);
-	ret = write_and_map_eb(root->fs_info, eb);
-	free_extent_buffer(eb);
+	ret = write_data_to_disk(root->fs_info, body, key.objectid, sectorsize);
 	if (ret)
 		return ret;
 

kernel-shared/disk-io.c

@@ -462,27 +462,6 @@ struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
 	return eb;
 }
 
-int write_and_map_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb)
-{
-	int ret;
-	u64 *raid_map = NULL;
-	struct btrfs_multi_bio *multi = NULL;
-
-	/* write_data_to_disk() will handle all mirrors and RAID56. */
-	ret = write_data_to_disk(fs_info, eb->data, eb->start, eb->len);
-	if (ret < 0) {
-		errno = -ret;
-		error("failed to write bytenr %llu length %u: %m",
-			eb->start, eb->len);
-		goto out;
-	}
-
-out:
-	kfree(raid_map);
-	kfree(multi);
-	return ret;
-}
-
 int write_tree_block(struct btrfs_trans_handle *trans,
 		     struct btrfs_fs_info *fs_info,
 		     struct extent_buffer *eb)
@@ -500,7 +479,7 @@ int write_tree_block(struct btrfs_trans_handle *trans,
 	btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 	csum_tree_block(fs_info, eb, 0);
 
-	return write_and_map_eb(fs_info, eb);
+	return write_data_to_disk(fs_info, eb->data, eb->start, eb->len);
 }
 
 void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,

kernel-shared/disk-io.h

@@ -222,7 +222,6 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 int write_tree_block(struct btrfs_trans_handle *trans,
 		     struct btrfs_fs_info *fs_info,
 		     struct extent_buffer *eb);
-int write_and_map_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb);
 int btrfs_fs_roots_compare_roots(struct rb_node *node1, struct rb_node *node2);
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     struct btrfs_fs_info *fs_info,

mkfs/rootdir.c

@@ -316,7 +316,7 @@ static int add_file_items(struct btrfs_trans_handle *trans,
 	u64 file_pos = 0;
 	u64 cur_bytes;
 	u64 total_bytes;
-	struct extent_buffer *eb = NULL;
+	void *buf = NULL;
 	int fd;
 
 	if (st->st_size == 0)
@@ -358,12 +358,8 @@ static int add_file_items(struct btrfs_trans_handle *trans,
 	/* round up our st_size to the FS blocksize */
 	total_bytes = (u64)blocks * sectorsize;
 
-	/*
-	 * do our IO in extent buffers so it can work
-	 * against any raid type
-	 */
-	eb = calloc(1, sizeof(*eb) + sectorsize);
-	if (!eb) {
+	buf = malloc(sectorsize);
+	if (!buf) {
 		ret = -ENOMEM;
 		goto end;
 	}
@@ -385,37 +381,28 @@ static int add_file_items(struct btrfs_trans_handle *trans,
 
 	while (bytes_read < cur_bytes) {
 
-		memset(eb->data, 0, sectorsize);
+		memset(buf, 0, sectorsize);
 
-		ret_read = pread(fd, eb->data, sectorsize, file_pos +
-				   bytes_read);
+		ret_read = pread(fd, buf, sectorsize, file_pos + bytes_read);
 		if (ret_read == -1) {
 			error("cannot read %s at offset %llu length %u: %m",
 				path_name, file_pos + bytes_read, sectorsize);
 			goto end;
 		}
 
-		eb->start = first_block + bytes_read;
-		eb->len = sectorsize;
-		eb->fs_info = root->fs_info;
+		ret = write_data_to_disk(root->fs_info, buf,
+					 first_block + bytes_read, sectorsize);
+		if (ret) {
+			error("failed to write %s", path_name);
+			goto end;
+		}
 
-		/*
-		 * we're doing the csum before we record the extent, but
-		 * that's ok
-		 */
 		ret = btrfs_csum_file_block(trans,
 				first_block + bytes_read + sectorsize,
-				first_block + bytes_read,
-				eb->data, sectorsize);
+				first_block + bytes_read, buf, sectorsize);
 		if (ret)
 			goto end;
 
-		ret = write_and_map_eb(root->fs_info, eb);
-		if (ret) {
-			error("failed to write %s", path_name);
-			goto end;
-		}
-
 		bytes_read += sectorsize;
 	}
 
@@ -434,7 +421,7 @@ static int add_file_items(struct btrfs_trans_handle *trans,
 		goto again;
 
 end:
-	free(eb);
+	free(buf);
 	close(fd);
 	return ret;
 }