On 21.11.18 г. 21:03 ч., Josef Bacik wrote:
> may_commit_transaction will skip committing the transaction if we don't
> have enough pinned space or if we're trying to find space for a SYSTEM
> chunk. However if we have pending free block groups in this transaction
> we still want to commit as we may be able to allocate a chunk to make
> our reservation. So instead of just returning ENOSPC, check if we have
> free block groups pending, and if so commit the transaction to allow us
> to use that free space.
>
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> Reviewed-by: Omar Sandoval <osandov@xxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/extent-tree.c | 33 +++++++++++++++++++--------------
> 1 file changed, 19 insertions(+), 14 deletions(-)
>
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 8af68b13fa27..0dca250dc02e 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -4843,10 +4843,18 @@ static int may_commit_transaction(struct btrfs_fs_info *fs_info,
> if (!bytes)
> return 0;
>
> - /* See if there is enough pinned space to make this reservation */
> - if (__percpu_counter_compare(&space_info->total_bytes_pinned,
> - bytes,
> - BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0)
> + trans = btrfs_join_transaction(fs_info->extent_root);
> + if (IS_ERR(trans))
> + return PTR_ERR(trans);
> +
> + /*
> + * See if there is enough pinned space to make this reservation, or if
> + * we have bg's that are going to be freed, allowing us to possibly do a
> + * chunk allocation the next loop through.
> + */
> + if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags) ||
> + __percpu_counter_compare(&space_info->total_bytes_pinned, bytes,
> + BTRFS_TOTAL_BYTES_PINNED_BATCH) >= 0)
> goto commit;
>
> /*
> @@ -4854,7 +4862,7 @@ static int may_commit_transaction(struct btrfs_fs_info *fs_info,
> * this reservation.
> */
> if (space_info != delayed_rsv->space_info)
> - return -ENOSPC;
> + goto enospc;
>
> spin_lock(&delayed_rsv->lock);
> reclaim_bytes += delayed_rsv->reserved;
> @@ -4868,17 +4876,14 @@ static int may_commit_transaction(struct btrfs_fs_info *fs_info,
> bytes -= reclaim_bytes;
>
> if (__percpu_counter_compare(&space_info->total_bytes_pinned,
> - bytes,
> - BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0) {
> - return -ENOSPC;
> - }
> -
> + bytes,
> + BTRFS_TOTAL_BYTES_PINNED_BATCH) < 0)
> + goto enospc;
> commit:
> - trans = btrfs_join_transaction(fs_info->extent_root);
> - if (IS_ERR(trans))
> - return -ENOSPC;
> -
> return btrfs_commit_transaction(trans);
> +enospc:
> + btrfs_end_transaction(trans);
> + return -ENOSPC;
> }
>
> /*
>
