[PATCH] btrfs: Use kvzalloc instead of kzalloc/vmalloc in alloc_bitmap

From: Vinnie Magro
Date: Thu May 25 2017 - 15:18:20 EST


Replace alloc_bitmap with call to kvzalloc. kvzalloc preserves the
same fallback heuristic.

Signed-off-by: Vinnie Magro <vmagro@xxxxxx>
---
fs/btrfs/free-space-tree.c | 23 ++---------------------
1 file changed, 2 insertions(+), 21 deletions(-)

diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index fc0bd84..9e87129 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -151,25 +151,6 @@ static inline u32 free_space_bitmap_size(u64 size, u32 sectorsize)
return DIV_ROUND_UP((u32)div_u64(size, sectorsize), BITS_PER_BYTE);
}

-static u8 *alloc_bitmap(u32 bitmap_size)
-{
- void *mem;
-
- /*
- * The allocation size varies, observed numbers were < 4K up to 16K.
- * Using vmalloc unconditionally would be too heavy, we'll try
- * contiguous allocations first.
- */
- if (bitmap_size <= PAGE_SIZE)
- return kzalloc(bitmap_size, GFP_NOFS);
-
- mem = kzalloc(bitmap_size, GFP_NOFS | __GFP_NOWARN);
- if (mem)
- return mem;
-
- return __vmalloc(bitmap_size, GFP_NOFS | __GFP_ZERO, PAGE_KERNEL);
-}
-
int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group,
@@ -189,7 +170,7 @@ int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,

bitmap_size = free_space_bitmap_size(block_group->key.offset,
fs_info->sectorsize);
- bitmap = alloc_bitmap(bitmap_size);
+ bitmap = kvzalloc(bitmap_size, GFP_NOFS);
if (!bitmap) {
ret = -ENOMEM;
goto out;
@@ -330,7 +311,7 @@ int convert_free_space_to_extents(struct btrfs_trans_handle *trans,

bitmap_size = free_space_bitmap_size(block_group->key.offset,
fs_info->sectorsize);
- bitmap = alloc_bitmap(bitmap_size);
+ bitmap = kvzalloc(bitmap_size, GFP_NOFS);
if (!bitmap) {
ret = -ENOMEM;
goto out;
--
2.9.3