[PATCH 4.4 01/19] btrfs: cow_file_range() num_bytes and disk_num_bytes are same

From: Greg Kroah-Hartman
Date: Tue Jul 07 2020 - 11:10:30 EST


From: Anand Jain <Anand.Jain@xxxxxxxxxx>

[ Upstream commit 3752d22fcea160cc2493e34f5e0e41cdd7fdd921 ]

This patch deletes local variable disk_num_bytes as its value
is same as num_bytes in the function cow_file_range().

Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/btrfs/inode.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 972475eeb2dd0..ef8ed0cd8075a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -926,7 +926,6 @@ static noinline int cow_file_range(struct inode *inode,
u64 alloc_hint = 0;
u64 num_bytes;
unsigned long ram_size;
- u64 disk_num_bytes;
u64 cur_alloc_size;
u64 blocksize = root->sectorsize;
struct btrfs_key ins;
@@ -942,7 +941,6 @@ static noinline int cow_file_range(struct inode *inode,

num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
- disk_num_bytes = num_bytes;

/* if this is a small write inside eof, kick off defrag */
if (num_bytes < 64 * 1024 &&
@@ -969,16 +967,15 @@ static noinline int cow_file_range(struct inode *inode,
}
}

- BUG_ON(disk_num_bytes >
- btrfs_super_total_bytes(root->fs_info->super_copy));
+ BUG_ON(num_bytes > btrfs_super_total_bytes(root->fs_info->super_copy));

alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);

- while (disk_num_bytes > 0) {
+ while (num_bytes > 0) {
unsigned long op;

- cur_alloc_size = disk_num_bytes;
+ cur_alloc_size = num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size,
root->sectorsize, 0, alloc_hint,
&ins, 1, 1);
@@ -1033,7 +1030,7 @@ static noinline int cow_file_range(struct inode *inode,
goto out_drop_extent_cache;
}

- if (disk_num_bytes < cur_alloc_size)
+ if (num_bytes < cur_alloc_size)
break;

/* we're not doing compressed IO, don't unlock the first
@@ -1050,8 +1047,10 @@ static noinline int cow_file_range(struct inode *inode,
start + ram_size - 1, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC,
op);
- disk_num_bytes -= cur_alloc_size;
- num_bytes -= cur_alloc_size;
+ if (num_bytes < cur_alloc_size)
+ num_bytes = 0;
+ else
+ num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
}
--
2.25.1