btrfs: cleanup for open-coded alignment
Though most of the btrfs codes are using ALIGN macro for page alignment,
there are still some codes using open-coded alignment like the
following:
------
u64 mask = ((u64)root->stripesize - 1);
u64 ret = (val + mask) & ~mask;
------
Or even hidden one:
------
num_bytes = (end - start + blocksize) & ~(blocksize - 1);
------
Sometimes these open-coded alignment is not so easy to understand for
newbie like me.
This commit changes the open-coded alignment to the ALIGN macro for a
better readability.
Also there is a previous patch from David Sterba with similar changes,
but the patch is for 3.2 kernel and seems not merged.
http://www.spinics.net/lists/linux-btrfs/msg12747.html
Cc: David Sterba <dave@jikos.cz>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index be09654..9ef7a5b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -233,8 +233,7 @@
u64 isize = i_size_read(inode);
u64 actual_end = min(end + 1, isize);
u64 inline_len = actual_end - start;
- u64 aligned_end = (end + root->sectorsize - 1) &
- ~((u64)root->sectorsize - 1);
+ u64 aligned_end = ALIGN(end, root->sectorsize);
u64 data_len = inline_len;
int ret;
@@ -391,7 +390,7 @@
* a compressed extent to 128k.
*/
total_compressed = min(total_compressed, max_uncompressed);
- num_bytes = (end - start + blocksize) & ~(blocksize - 1);
+ num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
total_in = 0;
ret = 0;
@@ -490,15 +489,13 @@
* up to a block size boundary so the allocator does sane
* things
*/
- total_compressed = (total_compressed + blocksize - 1) &
- ~(blocksize - 1);
+ total_compressed = ALIGN(total_compressed, blocksize);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk
*/
- total_in = (total_in + PAGE_CACHE_SIZE - 1) &
- ~(PAGE_CACHE_SIZE - 1);
+ total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
if (total_compressed >= total_in) {
will_compress = 0;
} else {
@@ -856,7 +853,7 @@
BUG_ON(btrfs_is_free_space_inode(inode));
- num_bytes = (end - start + blocksize) & ~(blocksize - 1);
+ num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
disk_num_bytes = num_bytes;
@@ -4015,7 +4012,6 @@
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
- u64 mask = root->sectorsize - 1;
u32 found_type = (u8)-1;
int found_extent;
int del_item;
@@ -4039,7 +4035,8 @@
* extent just the way it is.
*/
if (root->ref_cows || root == root->fs_info->tree_root)
- btrfs_drop_extent_cache(inode, (new_size + mask) & (~mask), (u64)-1, 0);
+ btrfs_drop_extent_cache(inode, ALIGN(new_size,
+ root->sectorsize), (u64)-1, 0);
/*
* This function is also used to drop the items in the log tree before
@@ -4118,10 +4115,9 @@
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
- extent_num_bytes = new_size -
- found_key.offset + root->sectorsize - 1;
- extent_num_bytes = extent_num_bytes &
- ~((u64)root->sectorsize - 1);
+ extent_num_bytes = ALIGN(new_size -
+ found_key.offset,
+ root->sectorsize);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes -
@@ -4357,9 +4353,8 @@
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
- u64 mask = root->sectorsize - 1;
- u64 hole_start = (oldsize + mask) & ~mask;
- u64 block_end = (size + mask) & ~mask;
+ u64 hole_start = ALIGN(oldsize, root->sectorsize);
+ u64 block_end = ALIGN(size, root->sectorsize);
u64 last_byte;
u64 cur_offset;
u64 hole_size;
@@ -4392,7 +4387,7 @@
break;
}
last_byte = min(extent_map_end(em), block_end);
- last_byte = (last_byte + mask) & ~mask;
+ last_byte = ALIGN(last_byte , root->sectorsize);
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
struct extent_map *hole_em;
hole_size = last_byte - cur_offset;
@@ -6111,8 +6106,7 @@
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size_t size;
size = btrfs_file_extent_inline_len(leaf, item);
- extent_end = (extent_start + size + root->sectorsize - 1) &
- ~((u64)root->sectorsize - 1);
+ extent_end = ALIGN(extent_start + size, root->sectorsize);
}
if (start >= extent_end) {
@@ -6184,8 +6178,7 @@
copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
size - extent_offset);
em->start = extent_start + extent_offset;
- em->len = (copy_size + root->sectorsize - 1) &
- ~((u64)root->sectorsize - 1);
+ em->len = ALIGN(copy_size, root->sectorsize);
em->orig_block_len = em->len;
em->orig_start = em->start;
if (compress_type) {