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>

6 files changed, 25 insertions, 38 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 8520354f086e..5681a91ed400 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3431,7 +3431,7 @@ int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
         int ret = 0, committed = 0, alloc_chunk = 1;
 
         /* make sure bytes are sectorsize aligned */
-        bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
+        bytes = ALIGN(bytes, root->sectorsize);
 
         if (root == root->fs_info->tree_root ||
             BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID) {
@@ -3526,7 +3526,7 @@ void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
         struct btrfs_space_info *data_sinfo;
 
         /* make sure bytes are sectorsize aligned */
-        bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
+        bytes = ALIGN(bytes, root->sectorsize);
 
         data_sinfo = root->fs_info->data_sinfo;
         spin_lock(&data_sinfo->lock);
@@ -5607,10 +5607,7 @@ static u64 stripe_align(struct btrfs_root *root,
                         struct btrfs_block_group_cache *cache,
                         u64 val, u64 num_bytes)
 {
-        u64 mask;
-        u64 ret;
-        mask = ((u64)root->stripesize - 1);
-        ret = (val + mask) & ~mask;
+        u64 ret = ALIGN(val, root->stripesize);
         return ret;
 }
 
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 66f999b97cbb..597ab8966c80 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2686,7 +2686,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
 
                 iosize = min(extent_map_end(em) - cur, end - cur + 1);
                 cur_end = min(extent_map_end(em) - 1, end);
-                iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
+                iosize = ALIGN(iosize, blocksize);
                 if (this_bio_flag & EXTENT_BIO_COMPRESSED) {
                         disk_io_size = em->block_len;
                         sector = em->block_start >> 9;
@@ -2977,7 +2977,7 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
                 BUG_ON(extent_map_end(em) <= cur);
                 BUG_ON(end < cur);
                 iosize = min(extent_map_end(em) - cur, end - cur + 1);
-                iosize = (iosize + blocksize - 1) & ~((u64)blocksize - 1);
+                iosize = ALIGN(iosize, blocksize);
                 sector = (em->block_start + extent_offset) >> 9;
                 bdev = em->bdev;
                 block_start = em->block_start;
@@ -3664,7 +3664,7 @@ int extent_invalidatepage(struct extent_io_tree *tree,
         u64 end = start + PAGE_CACHE_SIZE - 1;
         size_t blocksize = page->mapping->host->i_sb->s_blocksize;
 
-        start += (offset + blocksize - 1) & ~(blocksize - 1);
+        start += ALIGN(offset, blocksize);
         if (start > end)
                 return 0;
 
@@ -3783,7 +3783,7 @@ static struct extent_map *get_extent_skip_holes(struct inode *inode,
                 len = last - offset;
                 if (len == 0)
                         break;
-                len = (len + sectorsize - 1) & ~(sectorsize - 1);
+                len = ALIGN(len, sectorsize);
                 em = get_extent(inode, NULL, 0, offset, len, 0);
                 if (IS_ERR_OR_NULL(em))
                         return em;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 6e6dd8cdad92..83c790d84038 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -510,8 +510,7 @@ int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
         loff_t isize = i_size_read(inode);
 
         start_pos = pos & ~((u64)root->sectorsize - 1);
-        num_bytes = (write_bytes + pos - start_pos +
-                    root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
+        num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
 
         end_of_last_block = start_pos + num_bytes - 1;
         err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index be09654e11b9..9ef7a5b1b77e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -233,8 +233,7 @@ static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
         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 @@ again:
          * 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 @@ cont:
                  * 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 @@ static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
 
         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 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
         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 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
          * 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 @@ search_again:
                         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 @@ int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
         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 @@ int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
                         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 @@ again:
         } 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 @@ again:
                 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) {
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 1a79087c4575..e8b7a68e1b37 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -484,7 +484,6 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
                                       struct btrfs_key *key)
 {
         int found_type;
-        u64 mask = root->sectorsize - 1;
         u64 extent_end;
         u64 start = key->offset;
         u64 saved_nbytes;
@@ -501,7 +500,7 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
                 extent_end = start + btrfs_file_extent_num_bytes(eb, item);
         else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
                 size = btrfs_file_extent_inline_len(eb, item);
-                extent_end = (start + size + mask) & ~mask;
+                extent_end = ALIGN(start + size, root->sectorsize);
         } else {
                 ret = 0;
                 goto out;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 538c5cfa005f..db72e0cc6f87 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4556,8 +4556,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
         num_stripes = 1;
         stripe_index = 0;
         stripe_nr_orig = stripe_nr;
-        stripe_nr_end = (offset + *length + map->stripe_len - 1) &
-                        (~(map->stripe_len - 1));
+        stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
         do_div(stripe_nr_end, map->stripe_len);
         stripe_end_offset = stripe_nr_end * map->stripe_len -
                             (offset + *length);