Btrfs: use linux/sizes.h to represent constants

We use many constants to represent size and offset value. And to make
code readable we use '256 * 1024 * 1024' instead of '268435456' to
represent '256MB'. However we can make far more readable with 'SZ_256MB'
which is defined in the 'linux/sizes.h'.

So this patch replaces 'xxx * 1024 * 1024' kind of expression with
single 'SZ_xxxMB' if 'xxx' is a power of 2 then 'xxx * SZ_1M' if 'xxx' is
not a power of 2. And I haven't touched to '4096' & '8192' because it's
more intuitive than 'SZ_4KB' & 'SZ_8KB'.

Signed-off-by: Byongho Lee <[e-mail]>
Signed-off-by: David Sterba <[e-mail]>

fs/btrfs/ctree.c

···
 		return 0;
 	}
 
-	search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
+	search_start = buf->start & ~((u64)SZ_1G - 1);
 
 	if (parent)
 		btrfs_set_lock_blocking(parent);

fs/btrfs/ctree.h

···
 #include <linux/btrfs.h>
 #include <linux/workqueue.h>
 #include <linux/security.h>
+#include <linux/sizes.h>
 #include "extent_io.h"
 #include "extent_map.h"
 #include "async-thread.h"
···
 /* ioprio of readahead is set to idle */
 #define BTRFS_IOPRIO_READA (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0))
 
-#define BTRFS_DIRTY_METADATA_THRESH	(32 * 1024 * 1024)
+#define BTRFS_DIRTY_METADATA_THRESH	SZ_32M
 
-#define BTRFS_MAX_EXTENT_SIZE (128 * 1024 * 1024)
+#define BTRFS_MAX_EXTENT_SIZE SZ_128M
 
 /*
  * The key defines the order in the tree, and so it also defines (optimal)

fs/btrfs/disk-io.c

···
 
 	fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
 	fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
-				    4 * 1024 * 1024 / PAGE_CACHE_SIZE);
+				    SZ_4M / PAGE_CACHE_SIZE);
 
 	tree_root->nodesize = nodesize;
 	tree_root->sectorsize = sectorsize;

fs/btrfs/disk-io.h

···
 #ifndef __DISKIO__
 #define __DISKIO__
 
-#define BTRFS_SUPER_INFO_OFFSET (64 * 1024)
+#define BTRFS_SUPER_INFO_OFFSET SZ_64K
 #define BTRFS_SUPER_INFO_SIZE 4096
 
 #define BTRFS_SUPER_MIRROR_MAX	 3
···
 
 static inline u64 btrfs_sb_offset(int mirror)
 {
-	u64 start = 16 * 1024;
+	u64 start = SZ_16K;
 	if (mirror)
 		return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror);
 	return BTRFS_SUPER_INFO_OFFSET;

fs/btrfs/extent-tree.c

···
 			else
 				last = key.objectid + key.offset;
 
-			if (total_found > (1024 * 1024 * 2)) {
+			if (total_found > SZ_2M) {
 				total_found = 0;
 				if (wakeup)
 					wake_up(&caching_ctl->wait);
···
 	 * If this block group is smaller than 100 megs don't bother caching the
 	 * block group.
 	 */
-	if (block_group->key.offset < (100 * 1024 * 1024)) {
+	if (block_group->key.offset < (100 * SZ_1M)) {
 		spin_lock(&block_group->lock);
 		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
 		spin_unlock(&block_group->lock);
···
 	 * taking up quite a bit since it's not folded into the other space
 	 * cache.
 	 */
-	num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024);
+	num_pages = div_u64(block_group->key.offset, SZ_256M);
 	if (!num_pages)
 		num_pages = 1;
 
···
 	 */
 	if (force == CHUNK_ALLOC_LIMITED) {
 		thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
-		thresh = max_t(u64, 64 * 1024 * 1024,
-			       div_factor_fine(thresh, 1));
+		thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
 
 		if (num_bytes - num_allocated < thresh)
 			return 1;
 	}
 
-	if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8))
+	if (num_allocated + SZ_2M < div_factor(num_bytes, 8))
 		return 0;
 	return 1;
 }
···
 	 * transaction.
 	 */
 	if (trans->can_flush_pending_bgs &&
-	    trans->chunk_bytes_reserved >= (2 * 1024 * 1024ull)) {
+	    trans->chunk_bytes_reserved >= (u64)SZ_2M) {
 		btrfs_create_pending_block_groups(trans, trans->root);
 		btrfs_trans_release_chunk_metadata(trans);
 	}
···
 	return nr;
 }
 
-#define EXTENT_SIZE_PER_ITEM	(256 * 1024)
+#define EXTENT_SIZE_PER_ITEM	SZ_256K
 
 /*
  * shrink metadata reservation for delalloc
···
 	u64 expected;
 	u64 to_reclaim;
 
-	to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024,
-				16 * 1024 * 1024);
+	to_reclaim = min_t(u64, num_online_cpus() * SZ_1M, SZ_16M);
 	spin_lock(&space_info->lock);
 	if (can_overcommit(root, space_info, to_reclaim,
 			   BTRFS_RESERVE_FLUSH_ALL)) {
···
 	used = space_info->bytes_used + space_info->bytes_reserved +
 	       space_info->bytes_pinned + space_info->bytes_readonly +
 	       space_info->bytes_may_use;
-	if (can_overcommit(root, space_info, 1024 * 1024,
-			   BTRFS_RESERVE_FLUSH_ALL))
+	if (can_overcommit(root, space_info, SZ_1M, BTRFS_RESERVE_FLUSH_ALL))
 		expected = div_factor_fine(space_info->total_bytes, 95);
 	else
 		expected = div_factor_fine(space_info->total_bytes, 90);
···
 	spin_lock(&sinfo->lock);
 	spin_lock(&block_rsv->lock);
 
-	block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024);
+	block_rsv->size = min_t(u64, num_bytes, SZ_512M);
 
 	num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
 		    sinfo->bytes_reserved + sinfo->bytes_readonly +
···
 		return ret;
 
 	if (ssd)
-		*empty_cluster = 2 * 1024 * 1024;
+		*empty_cluster = SZ_2M;
 	if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
 		ret = &root->fs_info->meta_alloc_cluster;
 		if (!ssd)
-			*empty_cluster = 64 * 1024;
+			*empty_cluster = SZ_64K;
 	} else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) && ssd) {
 		ret = &root->fs_info->data_alloc_cluster;
 	}
···
 	if ((sinfo->flags &
 	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
 	    !force)
-		min_allocable_bytes = 1 * 1024 * 1024;
+		min_allocable_bytes = SZ_1M;
 	else
 		min_allocable_bytes = 0;
 

fs/btrfs/extent_io.c

···
 	u64 end = start + PAGE_CACHE_SIZE - 1;
 
 	if (gfpflags_allow_blocking(mask) &&
-	    page->mapping->host->i_size > 16 * 1024 * 1024) {
+	    page->mapping->host->i_size > SZ_16M) {
 		u64 len;
 		while (start <= end) {
 			len = end - start + 1;

fs/btrfs/free-space-cache.c

···
 #include "volumes.h"
 
 #define BITS_PER_BITMAP		(PAGE_CACHE_SIZE * 8)
-#define MAX_CACHE_BYTES_PER_GIG	(32 * 1024)
+#define MAX_CACHE_BYTES_PER_GIG	SZ_32K
 
 struct btrfs_trim_range {
 	u64 start;
···
 	 * at or below 32k, so we need to adjust how much memory we allow to be
 	 * used by extent based free space tracking
 	 */
-	if (size < 1024 * 1024 * 1024)
+	if (size < SZ_1G)
 		max_bytes = MAX_CACHE_BYTES_PER_GIG;
 	else
-		max_bytes = MAX_CACHE_BYTES_PER_GIG *
-			div_u64(size, 1024 * 1024 * 1024);
+		max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
 
 	/*
 	 * we want to account for 1 more bitmap than what we have so we can make
···
 	 * track of free space, and if we pass 1/2 of that we want to
 	 * start converting things over to using bitmaps
 	 */
-	ctl->extents_thresh = ((1024 * 32) / 2) /
-				sizeof(struct btrfs_free_space);
+	ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
 }
 
 /*

fs/btrfs/inode-map.c

···
 	}
 }
 
-#define INIT_THRESHOLD	(((1024 * 32) / 2) / sizeof(struct btrfs_free_space))
+#define INIT_THRESHOLD	((SZ_32K / 2) / sizeof(struct btrfs_free_space))
 #define INODES_PER_BITMAP (PAGE_CACHE_SIZE * 8)
 
 /*

fs/btrfs/inode.c

···
 	unsigned long nr_pages_ret = 0;
 	unsigned long total_compressed = 0;
 	unsigned long total_in = 0;
-	unsigned long max_compressed = 128 * 1024;
-	unsigned long max_uncompressed = 128 * 1024;
+	unsigned long max_compressed = SZ_128K;
+	unsigned long max_uncompressed = SZ_128K;
 	int i;
 	int will_compress;
 	int compress_type = root->fs_info->compress_type;
 	int redirty = 0;
 
 	/* if this is a small write inside eof, kick off a defrag */
-	if ((end - start + 1) < 16 * 1024 &&
+	if ((end - start + 1) < SZ_16K &&
 	    (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
 		btrfs_add_inode_defrag(NULL, inode);
 
···
 again:
 	will_compress = 0;
 	nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
-	nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
+	nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_CACHE_SIZE);
 
 	/*
 	 * we don't want to send crud past the end of i_size through
···
 	disk_num_bytes = num_bytes;
 
 	/* if this is a small write inside eof, kick off defrag */
-	if (num_bytes < 64 * 1024 &&
+	if (num_bytes < SZ_64K &&
 	    (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
 		btrfs_add_inode_defrag(NULL, inode);
 
···
 	 * atomic_sub_return implies a barrier for waitqueue_active
 	 */
 	if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
-	    5 * 1024 * 1024 &&
+	    5 * SZ_1M &&
 	    waitqueue_active(&root->fs_info->async_submit_wait))
 		wake_up(&root->fs_info->async_submit_wait);
 
···
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	unsigned long nr_pages;
 	u64 cur_end;
-	int limit = 10 * 1024 * 1024;
+	int limit = 10 * SZ_1M;
 
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
 			 1, 0, NULL, GFP_NOFS);
···
 		    !btrfs_test_opt(root, FORCE_COMPRESS))
 			cur_end = end;
 		else
-			cur_end = min(end, start + 512 * 1024 - 1);
+			cur_end = min(end, start + SZ_512K - 1);
 
 		async_cow->end = cur_end;
 		INIT_LIST_HEAD(&async_cow->extents);
···
 	 * up a huge file in a single leaf.  Most of the time that
 	 * bytes_deleted is > 0, it will be huge by the time we get here
 	 */
-	if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
+	if (be_nice && bytes_deleted > SZ_32M) {
 		if (btrfs_should_end_transaction(trans, root)) {
 			err = -EAGAIN;
 			goto error;
···
 
 	btrfs_free_path(path);
 
-	if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
+	if (be_nice && bytes_deleted > SZ_32M) {
 		unsigned long updates = trans->delayed_ref_updates;
 		if (updates) {
 			trans->delayed_ref_updates = 0;
···
 			}
 		}
 
-		cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
+		cur_bytes = min_t(u64, num_bytes, SZ_256M);
 		cur_bytes = max(cur_bytes, min_size);
 		/*
 		 * If we are severely fragmented we could end up with really

fs/btrfs/ioctl.c

···
 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 		ret = false;
 	else if ((em->block_start + em->block_len == next->block_start) &&
-		 (em->block_len > 128 * 1024 && next->block_len > 128 * 1024))
+		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
 		ret = false;
 
 	free_extent_map(next);
···
 	int defrag_count = 0;
 	int compress_type = BTRFS_COMPRESS_ZLIB;
 	u32 extent_thresh = range->extent_thresh;
-	unsigned long max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
+	unsigned long max_cluster = SZ_256K >> PAGE_CACHE_SHIFT;
 	unsigned long cluster = max_cluster;
-	u64 new_align = ~((u64)128 * 1024 - 1);
+	u64 new_align = ~((u64)SZ_128K - 1);
 	struct page **pages = NULL;
 
 	if (isize == 0)
···
 	}
 
 	if (extent_thresh == 0)
-		extent_thresh = 256 * 1024;
+		extent_thresh = SZ_256K;
 
 	/*
 	 * if we were not given a file, allocate a readahead
···
 
 	if (newer_than) {
 		ret = find_new_extents(root, inode, newer_than,
-				       &newer_off, 64 * 1024);
+				       &newer_off, SZ_64K);
 		if (!ret) {
 			range->start = newer_off;
 			/*
···
 			newer_off = max(newer_off + 1,
 					(u64)i << PAGE_CACHE_SHIFT);
 
-			ret = find_new_extents(root, inode,
-					       newer_than, &newer_off,
-					       64 * 1024);
+			ret = find_new_extents(root, inode, newer_than,
+					       &newer_off, SZ_64K);
 			if (!ret) {
 				range->start = newer_off;
 				i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
···
 		new_size = old_size + new_size;
 	}
 
-	if (new_size < 256 * 1024 * 1024) {
+	if (new_size < SZ_256M) {
 		ret = -EINVAL;
 		goto out_free;
 	}
···
 	struct inode *inode;
 	int ret;
 	size_t buf_size;
-	const size_t buf_limit = 16 * 1024 * 1024;
+	const size_t buf_limit = SZ_16M;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
···
 	return ret;
 }
 
-#define BTRFS_MAX_DEDUPE_LEN	(16 * 1024 * 1024)
+#define BTRFS_MAX_DEDUPE_LEN	SZ_16M
 
 static long btrfs_ioctl_file_extent_same(struct file *file,
 			struct btrfs_ioctl_same_args __user *argp)
···
 		goto out;
 	}
 
-	size = min_t(u32, loi->size, 64 * 1024);
+	size = min_t(u32, loi->size, SZ_64K);
 	inodes = init_data_container(size);
 	if (IS_ERR(inodes)) {
 		ret = PTR_ERR(inodes);

fs/btrfs/send.h

···
 #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
 #define BTRFS_SEND_STREAM_VERSION 1
 
-#define BTRFS_SEND_BUF_SIZE (1024 * 64)
-#define BTRFS_SEND_READ_SIZE (1024 * 48)
+#define BTRFS_SEND_BUF_SIZE SZ_64K
+#define BTRFS_SEND_READ_SIZE (48 * SZ_1K)
 
 enum btrfs_tlv_type {
 	BTRFS_TLV_U8,

fs/btrfs/super.c

···
 		 * btrfs starts at an offset of at least 1MB when doing chunk
 		 * allocation.
 		 */
-		skip_space = 1024 * 1024;
+		skip_space = SZ_1M;
 
 		/* user can set the offset in fs_info->alloc_start. */
 		if (fs_info->alloc_start &&

fs/btrfs/tests/extent-io-tests.c

···
 
 #include <linux/pagemap.h>
 #include <linux/sched.h>
+#include <linux/sizes.h>
 #include "btrfs-tests.h"
 #include "../extent_io.h"
 
···
 	struct page *page;
 	struct page *locked_page = NULL;
 	unsigned long index = 0;
-	u64 total_dirty = 256 * 1024 * 1024;
-	u64 max_bytes = 128 * 1024 * 1024;
+	u64 total_dirty = SZ_256M;
+	u64 max_bytes = SZ_128M;
 	u64 start, end, test_start;
 	u64 found;
 	int ret = -EINVAL;
···
 	 * |--- delalloc ---|
 	 *           |--- search ---|
 	 */
-	test_start = 64 * 1024 * 1024;
+	test_start = SZ_64M;
 	locked_page = find_lock_page(inode->i_mapping,
 				     test_start >> PAGE_CACHE_SHIFT);
 	if (!locked_page) {
···
 	 * Now to test where we run into a page that is no longer dirty in the
 	 * range we want to find.
 	 */
-	page = find_get_page(inode->i_mapping, (max_bytes + (1 * 1024 * 1024))
-			     >> PAGE_CACHE_SHIFT);
+	page = find_get_page(inode->i_mapping,
+			     (max_bytes + SZ_1M) >> PAGE_CACHE_SHIFT);
 	if (!page) {
 		test_msg("Couldn't find our page\n");
 		goto out_bits;

fs/btrfs/tests/free-space-tests.c

···
 	}
 
 	cache->key.objectid = 0;
-	cache->key.offset = 1024 * 1024 * 1024;
+	cache->key.offset = SZ_1G;
 	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
 	cache->sectorsize = 4096;
 	cache->full_stripe_len = 4096;
···
 	test_msg("Running extent only tests\n");
 
 	/* First just make sure we can remove an entire entry */
-	ret = btrfs_add_free_space(cache, 0, 4 * 1024 * 1024);
+	ret = btrfs_add_free_space(cache, 0, SZ_4M);
 	if (ret) {
 		test_msg("Error adding initial extents %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 0, 4 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, 0, SZ_4M);
 	if (ret) {
 		test_msg("Error removing extent %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, 0, 4 * 1024 * 1024)) {
+	if (test_check_exists(cache, 0, SZ_4M)) {
 		test_msg("Full remove left some lingering space\n");
 		return -1;
 	}
 
 	/* Ok edge and middle cases now */
-	ret = btrfs_add_free_space(cache, 0, 4 * 1024 * 1024);
+	ret = btrfs_add_free_space(cache, 0, SZ_4M);
 	if (ret) {
 		test_msg("Error adding half extent %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 3 * 1024 * 1024, 1 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, 3 * SZ_1M, SZ_1M);
 	if (ret) {
 		test_msg("Error removing tail end %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 0, 1 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, 0, SZ_1M);
 	if (ret) {
 		test_msg("Error removing front end %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 2 * 1024 * 1024, 4096);
+	ret = btrfs_remove_free_space(cache, SZ_2M, 4096);
 	if (ret) {
 		test_msg("Error removing middle piece %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, 0, 1 * 1024 * 1024)) {
+	if (test_check_exists(cache, 0, SZ_1M)) {
 		test_msg("Still have space at the front\n");
 		return -1;
 	}
 
-	if (test_check_exists(cache, 2 * 1024 * 1024, 4096)) {
+	if (test_check_exists(cache, SZ_2M, 4096)) {
 		test_msg("Still have space in the middle\n");
 		return -1;
 	}
 
-	if (test_check_exists(cache, 3 * 1024 * 1024, 1 * 1024 * 1024)) {
+	if (test_check_exists(cache, 3 * SZ_1M, SZ_1M)) {
 		test_msg("Still have space at the end\n");
 		return -1;
 	}
···
 
 	test_msg("Running bitmap only tests\n");
 
-	ret = test_add_free_space_entry(cache, 0, 4 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, 0, SZ_4M, 1);
 	if (ret) {
 		test_msg("Couldn't create a bitmap entry %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 0, 4 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, 0, SZ_4M);
 	if (ret) {
 		test_msg("Error removing bitmap full range %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, 0, 4 * 1024 * 1024)) {
+	if (test_check_exists(cache, 0, SZ_4M)) {
 		test_msg("Left some space in bitmap\n");
 		return -1;
 	}
 
-	ret = test_add_free_space_entry(cache, 0, 4 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, 0, SZ_4M, 1);
 	if (ret) {
 		test_msg("Couldn't add to our bitmap entry %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 1 * 1024 * 1024, 2 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, SZ_1M, SZ_2M);
 	if (ret) {
 		test_msg("Couldn't remove middle chunk %d\n", ret);
 		return ret;
···
 	next_bitmap_offset = (u64)(BITS_PER_BITMAP * 4096);
 
 	/* Test a bit straddling two bitmaps */
-	ret = test_add_free_space_entry(cache, next_bitmap_offset -
-				   (2 * 1024 * 1024), 4 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, next_bitmap_offset - SZ_2M,
+					SZ_4M, 1);
 	if (ret) {
 		test_msg("Couldn't add space that straddles two bitmaps %d\n",
 				ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, next_bitmap_offset -
-				      (1 * 1024 * 1024), 2 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, next_bitmap_offset - SZ_1M, SZ_2M);
 	if (ret) {
 		test_msg("Couldn't remove overlapping space %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, next_bitmap_offset - (1 * 1024 * 1024),
-			 2 * 1024 * 1024)) {
+	if (test_check_exists(cache, next_bitmap_offset - SZ_1M, SZ_2M)) {
 		test_msg("Left some space when removing overlapping\n");
 		return -1;
 	}
···
 	 * bitmap, but the free space completely in the extent and then
 	 * completely in the bitmap.
 	 */
-	ret = test_add_free_space_entry(cache, 4 * 1024 * 1024, 1 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, SZ_4M, SZ_1M, 1);
 	if (ret) {
 		test_msg("Couldn't create bitmap entry %d\n", ret);
 		return ret;
 	}
 
-	ret = test_add_free_space_entry(cache, 0, 1 * 1024 * 1024, 0);
+	ret = test_add_free_space_entry(cache, 0, SZ_1M, 0);
 	if (ret) {
 		test_msg("Couldn't add extent entry %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 0, 1 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, 0, SZ_1M);
 	if (ret) {
 		test_msg("Couldn't remove extent entry %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, 0, 1 * 1024 * 1024)) {
+	if (test_check_exists(cache, 0, SZ_1M)) {
 		test_msg("Left remnants after our remove\n");
 		return -1;
 	}
 
 	/* Now to add back the extent entry and remove from the bitmap */
-	ret = test_add_free_space_entry(cache, 0, 1 * 1024 * 1024, 0);
+	ret = test_add_free_space_entry(cache, 0, SZ_1M, 0);
 	if (ret) {
 		test_msg("Couldn't re-add extent entry %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 4 * 1024 * 1024, 1 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, SZ_4M, SZ_1M);
 	if (ret) {
 		test_msg("Couldn't remove from bitmap %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, 4 * 1024 * 1024, 1 * 1024 * 1024)) {
+	if (test_check_exists(cache, SZ_4M, SZ_1M)) {
 		test_msg("Left remnants in the bitmap\n");
 		return -1;
 	}
···
 	 * Ok so a little more evil, extent entry and bitmap at the same offset,
 	 * removing an overlapping chunk.
 	 */
-	ret = test_add_free_space_entry(cache, 1 * 1024 * 1024, 4 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, SZ_1M, SZ_4M, 1);
 	if (ret) {
 		test_msg("Couldn't add to a bitmap %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 512 * 1024, 3 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, SZ_512K, 3 * SZ_1M);
 	if (ret) {
 		test_msg("Couldn't remove overlapping space %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, 512 * 1024, 3 * 1024 * 1024)) {
+	if (test_check_exists(cache, SZ_512K, 3 * SZ_1M)) {
 		test_msg("Left over pieces after removing overlapping\n");
 		return -1;
 	}
···
 	__btrfs_remove_free_space_cache(cache->free_space_ctl);
 
 	/* Now with the extent entry offset into the bitmap */
-	ret = test_add_free_space_entry(cache, 4 * 1024 * 1024, 4 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, SZ_4M, SZ_4M, 1);
 	if (ret) {
 		test_msg("Couldn't add space to the bitmap %d\n", ret);
 		return ret;
 	}
 
-	ret = test_add_free_space_entry(cache, 2 * 1024 * 1024, 2 * 1024 * 1024, 0);
+	ret = test_add_free_space_entry(cache, SZ_2M, SZ_2M, 0);
 	if (ret) {
 		test_msg("Couldn't add extent to the cache %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 3 * 1024 * 1024, 4 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, 3 * SZ_1M, SZ_4M);
 	if (ret) {
 		test_msg("Problem removing overlapping space %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, 3 * 1024 * 1024, 4 * 1024 * 1024)) {
+	if (test_check_exists(cache, 3 * SZ_1M, SZ_4M)) {
 		test_msg("Left something behind when removing space");
 		return -1;
 	}
···
 	 *        [ del ]
 	 */
 	__btrfs_remove_free_space_cache(cache->free_space_ctl);
-	ret = test_add_free_space_entry(cache, bitmap_offset + 4 * 1024 * 1024,
-				   4 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, bitmap_offset + SZ_4M, SZ_4M, 1);
 	if (ret) {
 		test_msg("Couldn't add bitmap %d\n", ret);
 		return ret;
 	}
 
-	ret = test_add_free_space_entry(cache, bitmap_offset - 1 * 1024 * 1024,
-				   5 * 1024 * 1024, 0);
+	ret = test_add_free_space_entry(cache, bitmap_offset - SZ_1M,
+					5 * SZ_1M, 0);
 	if (ret) {
 		test_msg("Couldn't add extent entry %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, bitmap_offset + 1 * 1024 * 1024,
-				      5 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, bitmap_offset + SZ_1M, 5 * SZ_1M);
 	if (ret) {
 		test_msg("Failed to free our space %d\n", ret);
 		return ret;
 	}
 
-	if (test_check_exists(cache, bitmap_offset + 1 * 1024 * 1024,
-			 5 * 1024 * 1024)) {
+	if (test_check_exists(cache, bitmap_offset + SZ_1M, 5 * SZ_1M)) {
 		test_msg("Left stuff over\n");
 		return -1;
 	}
···
 	 * to return -EAGAIN back from btrfs_remove_extent, make sure this
 	 * doesn't happen.
 	 */
-	ret = test_add_free_space_entry(cache, 1 * 1024 * 1024, 2 * 1024 * 1024, 1);
+	ret = test_add_free_space_entry(cache, SZ_1M, SZ_2M, 1);
 	if (ret) {
 		test_msg("Couldn't add bitmap entry %d\n", ret);
 		return ret;
 	}
 
-	ret = test_add_free_space_entry(cache, 3 * 1024 * 1024, 1 * 1024 * 1024, 0);
+	ret = test_add_free_space_entry(cache, 3 * SZ_1M, SZ_1M, 0);
 	if (ret) {
 		test_msg("Couldn't add extent entry %d\n", ret);
 		return ret;
 	}
 
-	ret = btrfs_remove_free_space(cache, 1 * 1024 * 1024, 3 * 1024 * 1024);
+	ret = btrfs_remove_free_space(cache, SZ_1M, 3 * SZ_1M);
 	if (ret) {
 		test_msg("Error removing bitmap and extent overlapping %d\n", ret);
 		return ret;
···
 	/*
 	 * Extent entry covering free space range [128Mb - 256Kb, 128Mb - 128Kb[
 	 */
-	ret = test_add_free_space_entry(cache, 128 * 1024 * 1024 - 256 * 1024,
-					128 * 1024, 0);
+	ret = test_add_free_space_entry(cache, SZ_128M - SZ_256K, SZ_128K, 0);
 	if (ret) {
 		test_msg("Couldn't add extent entry %d\n", ret);
 		return ret;
 	}
 
 	/* Bitmap entry covering free space range [128Mb + 512Kb, 256Mb[ */
-	ret = test_add_free_space_entry(cache, 128 * 1024 * 1024 + 512 * 1024,
-					128 * 1024 * 1024 - 512 * 1024, 1);
+	ret = test_add_free_space_entry(cache, SZ_128M + SZ_512K,
+					SZ_128M - SZ_512K, 1);
 	if (ret) {
 		test_msg("Couldn't add bitmap entry %d\n", ret);
 		return ret;
···
 	 * [128Mb + 512Kb, 128Mb + 768Kb[
 	 */
 	ret = btrfs_remove_free_space(cache,
-				      128 * 1024 * 1024 + 768 * 1024,
-				      128 * 1024 * 1024 - 768 * 1024);
+				      SZ_128M + 768 * SZ_1K,
+				      SZ_128M - 768 * SZ_1K);
 	if (ret) {
 		test_msg("Failed to free part of bitmap space %d\n", ret);
 		return ret;
 	}
 
 	/* Confirm that only those 2 ranges are marked as free. */
-	if (!test_check_exists(cache, 128 * 1024 * 1024 - 256 * 1024,
-			       128 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M - SZ_256K, SZ_128K)) {
 		test_msg("Free space range missing\n");
 		return -ENOENT;
 	}
-	if (!test_check_exists(cache, 128 * 1024 * 1024 + 512 * 1024,
-			       256 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M + SZ_512K, SZ_256K)) {
 		test_msg("Free space range missing\n");
 		return -ENOENT;
 	}
···
 	 * Confirm that the bitmap range [128Mb + 768Kb, 256Mb[ isn't marked
 	 * as free anymore.
 	 */
-	if (test_check_exists(cache, 128 * 1024 * 1024 + 768 * 1024,
-			      128 * 1024 * 1024 - 768 * 1024)) {
+	if (test_check_exists(cache, SZ_128M + 768 * SZ_1K,
+			      SZ_128M - 768 * SZ_1K)) {
 		test_msg("Bitmap region not removed from space cache\n");
 		return -EINVAL;
 	}
···
 	 * Confirm that the region [128Mb + 256Kb, 128Mb + 512Kb[, which is
 	 * covered by the bitmap, isn't marked as free.
 	 */
-	if (test_check_exists(cache, 128 * 1024 * 1024 + 256 * 1024,
-			      256 * 1024)) {
+	if (test_check_exists(cache, SZ_128M + SZ_256K, SZ_256K)) {
 		test_msg("Invalid bitmap region marked as free\n");
 		return -EINVAL;
 	}
···
 	 * Confirm that the region [128Mb, 128Mb + 256Kb[, which is covered
 	 * by the bitmap too, isn't marked as free either.
 	 */
-	if (test_check_exists(cache, 128 * 1024 * 1024,
-			      256 * 1024)) {
+	if (test_check_exists(cache, SZ_128M, SZ_256K)) {
 		test_msg("Invalid bitmap region marked as free\n");
 		return -EINVAL;
 	}
···
 	 * lets make sure the free space cache marks it as free in the bitmap,
 	 * and doesn't insert a new extent entry to represent this region.
 	 */
-	ret = btrfs_add_free_space(cache, 128 * 1024 * 1024, 512 * 1024);
+	ret = btrfs_add_free_space(cache, SZ_128M, SZ_512K);
 	if (ret) {
 		test_msg("Error adding free space: %d\n", ret);
 		return ret;
 	}
 	/* Confirm the region is marked as free. */
-	if (!test_check_exists(cache, 128 * 1024 * 1024, 512 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M, SZ_512K)) {
 		test_msg("Bitmap region not marked as free\n");
 		return -ENOENT;
 	}
···
 	 * The goal is to test that the bitmap entry space stealing doesn't
 	 * steal this space region.
 	 */
-	ret = btrfs_add_free_space(cache, 128 * 1024 * 1024 + 16 * 1024 * 1024,
-				   4096);
+	ret = btrfs_add_free_space(cache, SZ_128M + SZ_16M, 4096);
 	if (ret) {
 		test_msg("Error adding free space: %d\n", ret);
 		return ret;
···
 	 * expand the range covered by the existing extent entry that represents
 	 * the free space [128Mb - 256Kb, 128Mb - 128Kb[.
 	 */
-	ret = btrfs_add_free_space(cache, 128 * 1024 * 1024 - 128 * 1024,
-				   128 * 1024);
+	ret = btrfs_add_free_space(cache, SZ_128M - SZ_128K, SZ_128K);
 	if (ret) {
 		test_msg("Error adding free space: %d\n", ret);
 		return ret;
 	}
 	/* Confirm the region is marked as free. */
-	if (!test_check_exists(cache, 128 * 1024 * 1024 - 128 * 1024,
-			       128 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M - SZ_128K, SZ_128K)) {
 		test_msg("Extent region not marked as free\n");
 		return -ENOENT;
 	}
···
 	 * that represents the 1Mb free space, and therefore we're able to
 	 * allocate the whole free space at once.
 	 */
-	if (!test_check_exists(cache, 128 * 1024 * 1024 - 256 * 1024,
-			       1 * 1024 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M - SZ_256K, SZ_1M)) {
 		test_msg("Expected region not marked as free\n");
 		return -ENOENT;
 	}
 
-	if (cache->free_space_ctl->free_space != (1 * 1024 * 1024 + 4096)) {
+	if (cache->free_space_ctl->free_space != (SZ_1M + 4096)) {
 		test_msg("Cache free space is not 1Mb + 4Kb\n");
 		return -EINVAL;
 	}
 
 	offset = btrfs_find_space_for_alloc(cache,
-					    0, 1 * 1024 * 1024, 0,
+					    0, SZ_1M, 0,
 					    &max_extent_size);
-	if (offset != (128 * 1024 * 1024 - 256 * 1024)) {
+	if (offset != (SZ_128M - SZ_256K)) {
 		test_msg("Failed to allocate 1Mb from space cache, returned offset is: %llu\n",
 			 offset);
 		return -EINVAL;
···
 	offset = btrfs_find_space_for_alloc(cache,
 					    0, 4096, 0,
 					    &max_extent_size);
-	if (offset != (128 * 1024 * 1024 + 16 * 1024 * 1024)) {
+	if (offset != (SZ_128M + SZ_16M)) {
 		test_msg("Failed to allocate 4Kb from space cache, returned offset is: %llu\n",
 			 offset);
 		return -EINVAL;
···
 	/*
 	 * Extent entry covering free space range [128Mb + 128Kb, 128Mb + 256Kb[
 	 */
-	ret = test_add_free_space_entry(cache, 128 * 1024 * 1024 + 128 * 1024,
-					128 * 1024, 0);
+	ret = test_add_free_space_entry(cache, SZ_128M + SZ_128K, SZ_128K, 0);
 	if (ret) {
 		test_msg("Couldn't add extent entry %d\n", ret);
 		return ret;
 	}
 
 	/* Bitmap entry covering free space range [0, 128Mb - 512Kb[ */
-	ret = test_add_free_space_entry(cache, 0,
-					128 * 1024 * 1024 - 512 * 1024, 1);
+	ret = test_add_free_space_entry(cache, 0, SZ_128M - SZ_512K, 1);
 	if (ret) {
 		test_msg("Couldn't add bitmap entry %d\n", ret);
 		return ret;
···
 	 * [128Mb + 128b, 128Mb + 256Kb[
 	 * [128Mb - 768Kb, 128Mb - 512Kb[
 	 */
-	ret = btrfs_remove_free_space(cache,
-				      0,
-				      128 * 1024 * 1024 - 768 * 1024);
+	ret = btrfs_remove_free_space(cache, 0, SZ_128M - 768 * SZ_1K);
 	if (ret) {
 		test_msg("Failed to free part of bitmap space %d\n", ret);
 		return ret;
 	}
 
 	/* Confirm that only those 2 ranges are marked as free. */
-	if (!test_check_exists(cache, 128 * 1024 * 1024 + 128 * 1024,
-			       128 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M + SZ_128K, SZ_128K)) {
 		test_msg("Free space range missing\n");
 		return -ENOENT;
 	}
-	if (!test_check_exists(cache, 128 * 1024 * 1024 - 768 * 1024,
-			       256 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M - 768 * SZ_1K, SZ_256K)) {
 		test_msg("Free space range missing\n");
 		return -ENOENT;
 	}
···
 	 * Confirm that the bitmap range [0, 128Mb - 768Kb[ isn't marked
 	 * as free anymore.
 	 */
-	if (test_check_exists(cache, 0,
-			      128 * 1024 * 1024 - 768 * 1024)) {
+	if (test_check_exists(cache, 0, SZ_128M - 768 * SZ_1K)) {
 		test_msg("Bitmap region not removed from space cache\n");
 		return -EINVAL;
 	}
···
 	 * Confirm that the region [128Mb - 512Kb, 128Mb[, which is
 	 * covered by the bitmap, isn't marked as free.
 	 */
-	if (test_check_exists(cache, 128 * 1024 * 1024 - 512 * 1024,
-			      512 * 1024)) {
+	if (test_check_exists(cache, SZ_128M - SZ_512K, SZ_512K)) {
 		test_msg("Invalid bitmap region marked as free\n");
 		return -EINVAL;
 	}
···
 	 * lets make sure the free space cache marks it as free in the bitmap,
 	 * and doesn't insert a new extent entry to represent this region.
 	 */
-	ret = btrfs_add_free_space(cache, 128 * 1024 * 1024 - 512 * 1024,
-				   512 * 1024);
+	ret = btrfs_add_free_space(cache, SZ_128M - SZ_512K, SZ_512K);
 	if (ret) {
 		test_msg("Error adding free space: %d\n", ret);
 		return ret;
 	}
 	/* Confirm the region is marked as free. */
-	if (!test_check_exists(cache, 128 * 1024 * 1024 - 512 * 1024,
-			       512 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M - SZ_512K, SZ_512K)) {
 		test_msg("Bitmap region not marked as free\n");
 		return -ENOENT;
 	}
···
 	 * The goal is to test that the bitmap entry space stealing doesn't
 	 * steal this space region.
 	 */
-	ret = btrfs_add_free_space(cache, 32 * 1024 * 1024, 8192);
+	ret = btrfs_add_free_space(cache, SZ_32M, 8192);
 	if (ret) {
 		test_msg("Error adding free space: %d\n", ret);
 		return ret;
···
 	 * expand the range covered by the existing extent entry that represents
 	 * the free space [128Mb + 128Kb, 128Mb + 256Kb[.
 	 */
-	ret = btrfs_add_free_space(cache, 128 * 1024 * 1024, 128 * 1024);
+	ret = btrfs_add_free_space(cache, SZ_128M, SZ_128K);
 	if (ret) {
 		test_msg("Error adding free space: %d\n", ret);
 		return ret;
 	}
 	/* Confirm the region is marked as free. */
-	if (!test_check_exists(cache, 128 * 1024 * 1024, 128 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M, SZ_128K)) {
 		test_msg("Extent region not marked as free\n");
 		return -ENOENT;
 	}
···
 	 * that represents the 1Mb free space, and therefore we're able to
 	 * allocate the whole free space at once.
 	 */
-	if (!test_check_exists(cache, 128 * 1024 * 1024 - 768 * 1024,
-			       1 * 1024 * 1024)) {
+	if (!test_check_exists(cache, SZ_128M - 768 * SZ_1K, SZ_1M)) {
 		test_msg("Expected region not marked as free\n");
 		return -ENOENT;
 	}
 
-	if (cache->free_space_ctl->free_space != (1 * 1024 * 1024 + 8192)) {
+	if (cache->free_space_ctl->free_space != (SZ_1M + 8192)) {
 		test_msg("Cache free space is not 1Mb + 8Kb\n");
 		return -EINVAL;
 	}
 
-	offset = btrfs_find_space_for_alloc(cache,
-					    0, 1 * 1024 * 1024, 0,
+	offset = btrfs_find_space_for_alloc(cache, 0, SZ_1M, 0,
 					    &max_extent_size);
-	if (offset != (128 * 1024 * 1024 - 768 * 1024)) {
+	if (offset != (SZ_128M - 768 * SZ_1K)) {
 		test_msg("Failed to allocate 1Mb from space cache, returned offset is: %llu\n",
 			 offset);
 		return -EINVAL;
···
 	offset = btrfs_find_space_for_alloc(cache,
 					    0, 8192, 0,
 					    &max_extent_size);
-	if (offset != (32 * 1024 * 1024)) {
+	if (offset != SZ_32M) {
 		test_msg("Failed to allocate 8Kb from space cache, returned offset is: %llu\n",
 			 offset);
 		return -EINVAL;

fs/btrfs/tests/inode-tests.c

···
 static void setup_file_extents(struct btrfs_root *root)
 {
 	int slot = 0;
-	u64 disk_bytenr = 1 * 1024 * 1024;
+	u64 disk_bytenr = SZ_1M;
 	u64 offset = 0;
 
 	/* First we want a hole */

fs/btrfs/volumes.c

···
 	 * we don't want to overwrite the superblock on the drive,
 	 * so we make sure to start at an offset of at least 1MB
 	 */
-	search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
+	search_start = max_t(u64, root->fs_info->alloc_start, SZ_1M);
 	return find_free_dev_extent_start(trans->transaction, device,
 					  num_bytes, search_start, start, len);
 }
···
 	list_for_each_entry(device, devices, dev_list) {
 		old_size = btrfs_device_get_total_bytes(device);
 		size_to_free = div_factor(old_size, 1);
-		size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
+		size_to_free = min_t(u64, size_to_free, SZ_1M);
 		if (!device->writeable ||
 		    btrfs_device_get_total_bytes(device) -
 		    btrfs_device_get_bytes_used(device) > size_to_free ||
···
 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
 {
 	/* TODO allow them to set a preferred stripe size */
-	return 64 * 1024;
+	return SZ_64K;
 }
 
 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
···
 	ncopies = btrfs_raid_array[index].ncopies;
 
 	if (type & BTRFS_BLOCK_GROUP_DATA) {
-		max_stripe_size = 1024 * 1024 * 1024;
+		max_stripe_size = SZ_1G;
 		max_chunk_size = 10 * max_stripe_size;
 		if (!devs_max)
 			devs_max = BTRFS_MAX_DEVS(info->chunk_root);
 	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
 		/* for larger filesystems, use larger metadata chunks */
-		if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
-			max_stripe_size = 1024 * 1024 * 1024;
+		if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
+			max_stripe_size = SZ_1G;
 		else
-			max_stripe_size = 256 * 1024 * 1024;
+			max_stripe_size = SZ_256M;
 		max_chunk_size = max_stripe_size;
 		if (!devs_max)
 			devs_max = BTRFS_MAX_DEVS(info->chunk_root);
 	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
-		max_stripe_size = 32 * 1024 * 1024;
+		max_stripe_size = SZ_32M;
 		max_chunk_size = 2 * max_stripe_size;
 		if (!devs_max)
 			devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;

fs/btrfs/volumes.h

···
 
 extern struct mutex uuid_mutex;
 
-#define BTRFS_STRIPE_LEN	(64 * 1024)
+#define BTRFS_STRIPE_LEN	SZ_64K
 
 struct buffer_head;
 struct btrfs_pending_bios {