On 30.01.20 г. 1:50 ч., Josef Bacik wrote:
> We have btrfs_wait_ordered_roots() which takes a u64 for nr, but
> btrfs_start_delalloc_roots() that takes an int for nr, which makes using
> them in conjunction, especially for something like (u64)-1, annoying and
> inconsistent. Fix btrfs_start_delalloc_roots() to take a u64 for nr and
> adjust start_delalloc_inodes() and it's callers appropriately.
nit: You could include one more sentence to be explicit about the fact
that now 'nr' management is delegated to start_delalloc_inodes i.e you
pass it as a pointer to that function which in turn will control when
btrfs_Start_delalloc_roots breaks out of its own loop.
>
> Part of adjusting the callers to this means changing
> btrfs_writeback_inodes_sb_nr() to take a u64 for items. This may be
> confusing because it seems unrelated, but the caller of
> btrfs_writeback_inodes_sb_nr() already passes in a u64, it's just the
> function variable that needs to be changed.
>
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> ---
> fs/btrfs/ctree.h | 2 +-
> fs/btrfs/dev-replace.c | 2 +-
> fs/btrfs/inode.c | 27 +++++++++++----------------
> fs/btrfs/ioctl.c | 2 +-
> fs/btrfs/space-info.c | 2 +-
> 5 files changed, 15 insertions(+), 20 deletions(-)
>
<snip>
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -9619,7 +9619,8 @@ static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode
> * some fairly slow code that needs optimization. This walks the list
> * of all the inodes with pending delalloc and forces them to disk.
> */
> -static int start_delalloc_inodes(struct btrfs_root *root, int nr, bool snapshot)
> +static int start_delalloc_inodes(struct btrfs_root *root, u64 *nr,
> + bool snapshot)
> {
> struct btrfs_inode *binode;
> struct inode *inode;
> @@ -9659,9 +9660,11 @@ static int start_delalloc_inodes(struct btrfs_root *root, int nr, bool snapshot)
> list_add_tail(&work->list, &works);
> btrfs_queue_work(root->fs_info->flush_workers,
> &work->work);
> - ret++;
> - if (nr != -1 && ret >= nr)
> - goto out;
> + if (*nr != U64_MAX) {
> + (*nr)--;
> + if (*nr == 0)
> + goto out;
> + }
> cond_resched();
> spin_lock(&root->delalloc_lock);
> }
> @@ -9686,18 +9689,15 @@ static int start_delalloc_inodes(struct btrfs_root *root, int nr, bool snapshot)
> int btrfs_start_delalloc_snapshot(struct btrfs_root *root)
> {
> struct btrfs_fs_info *fs_info = root->fs_info;
> - int ret;
> + u64 nr = U64_MAX;
This var is never used past start_delalloc_snapshot so you can remove it
and simply pass U64_MAX to start_delalloc_inodes.
>
> if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
> return -EROFS;
>
> - ret = start_delalloc_inodes(root, -1, true);
> - if (ret > 0)
> - ret = 0;
> - return ret;
> + return start_delalloc_inodes(root, &nr, true);
> }
>
> -int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int nr)
> +int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, u64 nr)
> {
> struct btrfs_root *root;
> struct list_head splice;
> @@ -9720,15 +9720,10 @@ int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int nr)
> &fs_info->delalloc_roots);
> spin_unlock(&fs_info->delalloc_root_lock);
>
> - ret = start_delalloc_inodes(root, nr, false);
> + ret = start_delalloc_inodes(root, &nr, false);
> btrfs_put_root(root);
> if (ret < 0)
> goto out;
> -
> - if (nr != -1) {
> - nr -= ret;
> - WARN_ON(nr < 0);
> - }
> spin_lock(&fs_info->delalloc_root_lock);
> }
> spin_unlock(&fs_info->delalloc_root_lock);
<snip>
