Commit e28b851e authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: remove extent_map::block_len member 



The extent_map::block_len is either extent_map::len (non-compressed
extent) or extent_map::disk_num_bytes (compressed extent).

Since we already have sanity checks to do the cross-checks between the
new and old members, we can drop the old extent_map::block_len now.

For most call sites, they can manually select extent_map::len or
extent_map::disk_num_bytes, since most if not all of them have checked
if the extent is compressed.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 4aa7b5d1

fs/btrfs/compression.c

+1 −1
Original line number Diff line number Diff line
@@ -585,7 +585,7 @@ void btrfs_submit_compressed_read(struct btrfs_bio *bbio) 
	}



	ASSERT(extent_map_is_compressed(em));

	compressed_len = em->block_len;

	compressed_len = em->disk_num_bytes;



	cb = alloc_compressed_bio(inode, file_offset, REQ_OP_READ,

				  end_bbio_compressed_read);

fs/btrfs/extent_map.c

+14 −27
Original line number Diff line number Diff line
@@ -183,11 +183,18 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset, 
	return NULL;

}



static inline u64 extent_map_block_len(const struct extent_map *em)

{

	if (extent_map_is_compressed(em))

		return em->disk_num_bytes;

	return em->len;

}



static inline u64 extent_map_block_end(const struct extent_map *em)

{

	if (em->block_start + em->block_len < em->block_start)

	if (em->block_start + extent_map_block_len(em) < em->block_start)

		return (u64)-1;

	return em->block_start + em->block_len;

	return em->block_start + extent_map_block_len(em);

}



static bool can_merge_extent_map(const struct extent_map *em)
@@ -290,10 +297,9 @@ static void dump_extent_map(struct btrfs_fs_info *fs_info, const char *prefix, 
	if (!IS_ENABLED(CONFIG_BTRFS_DEBUG))

		return;

	btrfs_crit(fs_info,

"%s, start=%llu len=%llu disk_bytenr=%llu disk_num_bytes=%llu ram_bytes=%llu offset=%llu block_start=%llu block_len=%llu flags=0x%x",

"%s, start=%llu len=%llu disk_bytenr=%llu disk_num_bytes=%llu ram_bytes=%llu offset=%llu block_start=%llu flags=0x%x",

		prefix, em->start, em->len, em->disk_bytenr, em->disk_num_bytes,

		em->ram_bytes, em->offset, em->block_start,

		em->block_len, em->flags);

		em->ram_bytes, em->offset, em->block_start, em->flags);

	ASSERT(0);

}
@@ -315,9 +321,6 @@ static void validate_extent_map(struct btrfs_fs_info *fs_info, struct extent_map 
			if (em->block_start != em->disk_bytenr)

				dump_extent_map(fs_info,

					"mismatch block_start/disk_bytenr/offset", em);

			if (em->disk_num_bytes != em->block_len)

				dump_extent_map(fs_info,

					"mismatch disk_num_bytes/block_len", em);

		} else if (em->block_start != em->disk_bytenr + em->offset) {

			dump_extent_map(fs_info,

				"mismatch block_start/disk_bytenr/offset", em);
@@ -355,7 +358,6 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em) 
		if (rb && can_merge_extent_map(merge) && mergeable_maps(merge, em)) {

			em->start = merge->start;

			em->len += merge->len;

			em->block_len += merge->block_len;

			em->block_start = merge->block_start;

			em->generation = max(em->generation, merge->generation);
@@ -376,7 +378,6 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em) 
		merge = rb_entry(rb, struct extent_map, rb_node);

	if (rb && can_merge_extent_map(merge) && mergeable_maps(em, merge)) {

		em->len += merge->len;

		em->block_len += merge->block_len;

		if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE)

			merge_ondisk_extents(em, merge);

		validate_extent_map(fs_info, em);
@@ -670,7 +671,6 @@ static noinline int merge_extent_mapping(struct btrfs_inode *inode, 
	if (em->block_start < EXTENT_MAP_LAST_BYTE &&

	    !extent_map_is_compressed(em)) {

		em->block_start += start_diff;

		em->block_len = em->len;

		em->offset += start_diff;

	}

	return add_extent_mapping(inode, em, 0);
@@ -890,17 +890,11 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end, 
			if (em->block_start < EXTENT_MAP_LAST_BYTE) {

				split->block_start = em->block_start;



				if (compressed)

					split->block_len = em->block_len;

				else

					split->block_len = split->len;

				split->disk_bytenr = em->disk_bytenr;

				split->disk_num_bytes = max(split->block_len,

							    em->disk_num_bytes);

				split->disk_num_bytes = em->disk_num_bytes;

				split->offset = em->offset;

				split->ram_bytes = em->ram_bytes;

			} else {

				split->block_len = 0;

				split->block_start = em->block_start;

				split->disk_bytenr = em->disk_bytenr;

				split->disk_num_bytes = 0;
@@ -930,23 +924,18 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end, 
			split->generation = gen;



			if (em->block_start < EXTENT_MAP_LAST_BYTE) {

				split->disk_num_bytes = max(em->block_len,

							    em->disk_num_bytes);

				split->disk_num_bytes = em->disk_num_bytes;

				split->offset = em->offset + end - em->start;

				split->ram_bytes = em->ram_bytes;

				if (compressed) {

					split->block_len = em->block_len;

				} else {

				if (!compressed) {

					const u64 diff = end - em->start;



					split->block_len = split->len;

					split->block_start += diff;

				}

			} else {

				split->disk_num_bytes = 0;

				split->offset = 0;

				split->ram_bytes = split->len;

				split->block_len = 0;

			}



			if (extent_map_in_tree(em)) {
@@ -1104,7 +1093,6 @@ int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre, 
	split_pre->disk_num_bytes = split_pre->len;

	split_pre->offset = 0;

	split_pre->block_start = new_logical;

	split_pre->block_len = split_pre->len;

	split_pre->ram_bytes = split_pre->len;

	split_pre->flags = flags;

	split_pre->generation = em->generation;
@@ -1123,7 +1111,6 @@ int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre, 
	split_mid->disk_num_bytes = split_mid->len;

	split_mid->offset = 0;

	split_mid->block_start = em->block_start + pre;

	split_mid->block_len = split_mid->len;

	split_mid->ram_bytes = split_mid->len;

	split_mid->flags = flags;

	split_mid->generation = em->generation;

fs/btrfs/extent_map.h

+0 −9
Original line number Diff line number Diff line
@@ -102,15 +102,6 @@ struct extent_map { 
	 */

	u64 block_start;



	/*

	 * The on-disk length for the file extent.

	 *

	 * For compressed extents it matches btrfs_file_extent_item::disk_num_bytes.

	 * For uncompressed extents it matches extent_map::len.

	 * For holes and inline extents it's -1 and shouldn't be used.

	 */

	u64 block_len;



	/*

	 * Generation of the extent map, for merged em it's the highest

	 * generation of all merged ems.

fs/btrfs/file-item.c

+0 −7
Original line number Diff line number Diff line
@@ -1307,11 +1307,9 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, 
		if (compress_type != BTRFS_COMPRESS_NONE) {

			extent_map_set_compression(em, compress_type);

			em->block_start = bytenr;

			em->block_len = em->disk_num_bytes;

		} else {

			bytenr += btrfs_file_extent_offset(leaf, fi);

			em->block_start = bytenr;

			em->block_len = em->len;

			if (type == BTRFS_FILE_EXTENT_PREALLOC)

				em->flags |= EXTENT_FLAG_PREALLOC;

		}
@@ -1324,11 +1322,6 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, 
		em->start = 0;

		em->len = fs_info->sectorsize;

		em->offset = 0;

		/*

		 * Initialize block_len with the same values

		 * as in inode.c:btrfs_get_extent().

		 */

		em->block_len = (u64)-1;

		extent_map_set_compression(em, compress_type);

	} else {

		btrfs_err(fs_info,

fs/btrfs/file.c

+0 −1
Original line number Diff line number Diff line
@@ -2349,7 +2349,6 @@ static int fill_holes(struct btrfs_trans_handle *trans, 


		hole_em->block_start = EXTENT_MAP_HOLE;

		hole_em->disk_bytenr = EXTENT_MAP_HOLE;

		hole_em->block_len = 0;

		hole_em->disk_num_bytes = 0;

		hole_em->generation = trans->transid;