On 3.12.18 г. 17:24 ч., Josef Bacik wrote:
> With the introduction of the per-inode block_rsv it became possible to
> have really really large reservation requests made because of data
> fragmentation. Since the ticket stuff assumed that we'd always have
> relatively small reservation requests it just killed all tickets if we
> were unable to satisfy the current request. However this is generally
> not the case anymore. So fix this logic to instead see if we had a
> ticket that we were able to give some reservation to, and if we were
> continue the flushing loop again. Likewise we make the tickets use the
> space_info_add_old_bytes() method of returning what reservation they did
> receive in hopes that it could satisfy reservations down the line.
>
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/extent-tree.c | 45 +++++++++++++++++++++++++--------------------
> 1 file changed, 25 insertions(+), 20 deletions(-)
>
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 2d0dd70570ca..0ee77a98f867 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -4801,6 +4801,7 @@ static void shrink_delalloc(struct btrfs_fs_info *fs_info, u64 to_reclaim,
> }
>
> struct reserve_ticket {
> + u64 orig_bytes;
> u64 bytes;
> int error;
> struct list_head list;
> @@ -5023,7 +5024,7 @@ static inline int need_do_async_reclaim(struct btrfs_fs_info *fs_info,
> !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
> }
>
> -static void wake_all_tickets(struct list_head *head)
> +static bool wake_all_tickets(struct list_head *head)
> {
> struct reserve_ticket *ticket;
>
> @@ -5032,7 +5033,10 @@ static void wake_all_tickets(struct list_head *head)
> list_del_init(&ticket->list);
> ticket->error = -ENOSPC;
> wake_up(&ticket->wait);
> + if (ticket->bytes != ticket->orig_bytes)
> + return true;
> }
> + return false;
> }
>
> /*
> @@ -5100,8 +5104,12 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
> if (flush_state > COMMIT_TRANS) {
> commit_cycles++;
> if (commit_cycles > 2) {
> - wake_all_tickets(&space_info->tickets);
> - space_info->flush = 0;
> + if (wake_all_tickets(&space_info->tickets)) {
> + flush_state = FLUSH_DELAYED_ITEMS_NR;
> + commit_cycles--;
> + } else {
> + space_info->flush = 0;
> + }
> } else {
> flush_state = FLUSH_DELAYED_ITEMS_NR;
> }
> @@ -5153,10 +5161,11 @@ static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
>
> static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
> struct btrfs_space_info *space_info,
> - struct reserve_ticket *ticket, u64 orig_bytes)
> + struct reserve_ticket *ticket)
>
> {
> DEFINE_WAIT(wait);
> + u64 reclaim_bytes = 0;
> int ret = 0;
>
> spin_lock(&space_info->lock);
> @@ -5177,14 +5186,12 @@ static int wait_reserve_ticket(struct btrfs_fs_info *fs_info,
> ret = ticket->error;
> if (!list_empty(&ticket->list))
> list_del_init(&ticket->list);
> - if (ticket->bytes && ticket->bytes < orig_bytes) {
> - u64 num_bytes = orig_bytes - ticket->bytes;
> - update_bytes_may_use(space_info, -num_bytes);
> - trace_btrfs_space_reservation(fs_info, "space_info",
> - space_info->flags, num_bytes, 0);
> - }
> + if (ticket->bytes && ticket->bytes < ticket->orig_bytes)
> + reclaim_bytes = ticket->orig_bytes - ticket->bytes;
> spin_unlock(&space_info->lock);
>
> + if (reclaim_bytes)
> + space_info_add_old_bytes(fs_info, space_info, reclaim_bytes);
> return ret;
> }
>
> @@ -5210,6 +5217,7 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
> {
> struct reserve_ticket ticket;
> u64 used;
> + u64 reclaim_bytes = 0;
> int ret = 0;
>
> ASSERT(orig_bytes);
> @@ -5245,6 +5253,7 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
> * the list and we will do our own flushing further down.
> */
> if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
> + ticket.orig_bytes = orig_bytes;
> ticket.bytes = orig_bytes;
> ticket.error = 0;
> init_waitqueue_head(&ticket.wait);
> @@ -5285,25 +5294,21 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
> return ret;
>
> if (flush == BTRFS_RESERVE_FLUSH_ALL)
> - return wait_reserve_ticket(fs_info, space_info, &ticket,
> - orig_bytes);
> + return wait_reserve_ticket(fs_info, space_info, &ticket);
>
> ret = 0;
> priority_reclaim_metadata_space(fs_info, space_info, &ticket);
> spin_lock(&space_info->lock);
> if (ticket.bytes) {
> - if (ticket.bytes < orig_bytes) {
> - u64 num_bytes = orig_bytes - ticket.bytes;
> - update_bytes_may_use(space_info, -num_bytes);
> - trace_btrfs_space_reservation(fs_info, "space_info",
> - space_info->flags,
> - num_bytes, 0);
> -
> - }
> + if (ticket.bytes < orig_bytes)
> + reclaim_bytes = orig_bytes - ticket.bytes;
> list_del_init(&ticket.list);
> ret = -ENOSPC;
> }
> spin_unlock(&space_info->lock);
> +
> + if (reclaim_bytes)
> + space_info_add_old_bytes(fs_info, space_info, reclaim_bytes);
> ASSERT(list_empty(&ticket.list));
> return ret;
> }
>
