On 22.11.18 г. 18:16 ч., David Sterba wrote:
> The async_cow::root is used to propagate fs_info to async_cow_submit.
> We can't use inode to reach it because it could become NULL after
> write without compression in async_cow_start.
>
> Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/inode.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index a88122b89f50..26b8bec7c2dc 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -358,7 +358,7 @@ struct async_extent {
>
> struct async_cow {
> struct inode *inode;
> - struct btrfs_root *root;
> + struct btrfs_fs_info *fs_info;
> struct page *locked_page;
> u64 start;
> u64 end;
> @@ -1144,13 +1144,11 @@ static noinline void async_cow_submit(struct btrfs_work *work)
> {
> struct btrfs_fs_info *fs_info;
> struct async_cow *async_cow;
> - struct btrfs_root *root;
> unsigned long nr_pages;
>
> async_cow = container_of(work, struct async_cow, work);
>
> - root = async_cow->root;
> - fs_info = root->fs_info;
> + fs_info = async_cow->fs_info;
> nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
> PAGE_SHIFT;
>
> @@ -1179,7 +1177,6 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
> {
> struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> struct async_cow *async_cow;
> - struct btrfs_root *root = BTRFS_I(inode)->root;
> unsigned long nr_pages;
> u64 cur_end;
>
> @@ -1189,7 +1186,7 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
> async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
> BUG_ON(!async_cow); /* -ENOMEM */
> async_cow->inode = igrab(inode);
> - async_cow->root = root;
> + async_cow->fs_info = fs_info;
> async_cow->locked_page = locked_page;
> async_cow->start = start;
> async_cow->write_flags = write_flags;
>
