On Wed, Aug 10, 2022 at 09:03:52AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> Because we are going to need them soon. API change only, no logic
> changes.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Would've been nice to do the xlog_grant_space_left move as a separate
change, but as I've already squinted at both to verify that there's
nothing changing here besides the function signature, let's just leave
this as it is:
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
(ok, I lie, I actually just open the patch twice in gvim, increase the
transparency on one of the gvims, and then overlay them :P)
--D
> ---
> fs/xfs/xfs_log.c | 157 +++++++++++++++++++++---------------------
> fs/xfs/xfs_log_priv.h | 2 -
> 2 files changed, 77 insertions(+), 82 deletions(-)
>
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 5b7c91a42edf..459c0f438c89 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -136,10 +136,10 @@ xlog_prepare_iovec(
> static void
> xlog_grant_sub_space(
> struct xlog *log,
> - atomic64_t *head,
> + struct xlog_grant_head *head,
> int bytes)
> {
> - int64_t head_val = atomic64_read(head);
> + int64_t head_val = atomic64_read(&head->grant);
> int64_t new, old;
>
> do {
> @@ -155,17 +155,17 @@ xlog_grant_sub_space(
>
> old = head_val;
> new = xlog_assign_grant_head_val(cycle, space);
> - head_val = atomic64_cmpxchg(head, old, new);
> + head_val = atomic64_cmpxchg(&head->grant, old, new);
> } while (head_val != old);
> }
>
> static void
> xlog_grant_add_space(
> struct xlog *log,
> - atomic64_t *head,
> + struct xlog_grant_head *head,
> int bytes)
> {
> - int64_t head_val = atomic64_read(head);
> + int64_t head_val = atomic64_read(&head->grant);
> int64_t new, old;
>
> do {
> @@ -184,7 +184,7 @@ xlog_grant_add_space(
>
> old = head_val;
> new = xlog_assign_grant_head_val(cycle, space);
> - head_val = atomic64_cmpxchg(head, old, new);
> + head_val = atomic64_cmpxchg(&head->grant, old, new);
> } while (head_val != old);
> }
>
> @@ -197,6 +197,63 @@ xlog_grant_head_init(
> spin_lock_init(&head->lock);
> }
>
> +/*
> + * Return the space in the log between the tail and the head. The head
> + * is passed in the cycle/bytes formal parms. In the special case where
> + * the reserve head has wrapped passed the tail, this calculation is no
> + * longer valid. In this case, just return 0 which means there is no space
> + * in the log. This works for all places where this function is called
> + * with the reserve head. Of course, if the write head were to ever
> + * wrap the tail, we should blow up. Rather than catch this case here,
> + * we depend on other ASSERTions in other parts of the code. XXXmiken
> + *
> + * If reservation head is behind the tail, we have a problem. Warn about it,
> + * but then treat it as if the log is empty.
> + *
> + * If the log is shut down, the head and tail may be invalid or out of whack, so
> + * shortcut invalidity asserts in this case so that we don't trigger them
> + * falsely.
> + */
> +static int
> +xlog_grant_space_left(
> + struct xlog *log,
> + struct xlog_grant_head *head)
> +{
> + int tail_bytes;
> + int tail_cycle;
> + int head_cycle;
> + int head_bytes;
> +
> + xlog_crack_grant_head(&head->grant, &head_cycle, &head_bytes);
> + xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
> + tail_bytes = BBTOB(tail_bytes);
> + if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
> + return log->l_logsize - (head_bytes - tail_bytes);
> + if (tail_cycle + 1 < head_cycle)
> + return 0;
> +
> + /* Ignore potential inconsistency when shutdown. */
> + if (xlog_is_shutdown(log))
> + return log->l_logsize;
> +
> + if (tail_cycle < head_cycle) {
> + ASSERT(tail_cycle == (head_cycle - 1));
> + return tail_bytes - head_bytes;
> + }
> +
> + /*
> + * The reservation head is behind the tail. In this case we just want to
> + * return the size of the log as the amount of space left.
> + */
> + xfs_alert(log->l_mp, "xlog_grant_space_left: head behind tail");
> + xfs_alert(log->l_mp, " tail_cycle = %d, tail_bytes = %d",
> + tail_cycle, tail_bytes);
> + xfs_alert(log->l_mp, " GH cycle = %d, GH bytes = %d",
> + head_cycle, head_bytes);
> + ASSERT(0);
> + return log->l_logsize;
> +}
> +
> STATIC void
> xlog_grant_head_wake_all(
> struct xlog_grant_head *head)
> @@ -277,7 +334,7 @@ xlog_grant_head_wait(
> spin_lock(&head->lock);
> if (xlog_is_shutdown(log))
> goto shutdown;
> - } while (xlog_space_left(log, &head->grant) < need_bytes);
> + } while (xlog_grant_space_left(log, head) < need_bytes);
>
> list_del_init(&tic->t_queue);
> return 0;
> @@ -322,7 +379,7 @@ xlog_grant_head_check(
> * otherwise try to get some space for this transaction.
> */
> *need_bytes = xlog_ticket_reservation(log, head, tic);
> - free_bytes = xlog_space_left(log, &head->grant);
> + free_bytes = xlog_grant_space_left(log, head);
> if (!list_empty_careful(&head->waiters)) {
> spin_lock(&head->lock);
> if (!xlog_grant_head_wake(log, head, &free_bytes) ||
> @@ -396,7 +453,7 @@ xfs_log_regrant(
> if (error)
> goto out_error;
>
> - xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
> + xlog_grant_add_space(log, &log->l_write_head, need_bytes);
> trace_xfs_log_regrant_exit(log, tic);
> xlog_verify_grant_tail(log);
> return 0;
> @@ -447,8 +504,8 @@ xfs_log_reserve(
> if (error)
> goto out_error;
>
> - xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
> - xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
> + xlog_grant_add_space(log, &log->l_reserve_head, need_bytes);
> + xlog_grant_add_space(log, &log->l_write_head, need_bytes);
> trace_xfs_log_reserve_exit(log, tic);
> xlog_verify_grant_tail(log);
> return 0;
> @@ -1114,7 +1171,7 @@ xfs_log_space_wake(
> ASSERT(!xlog_in_recovery(log));
>
> spin_lock(&log->l_write_head.lock);
> - free_bytes = xlog_space_left(log, &log->l_write_head.grant);
> + free_bytes = xlog_grant_space_left(log, &log->l_write_head);
> xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
> spin_unlock(&log->l_write_head.lock);
> }
> @@ -1123,7 +1180,7 @@ xfs_log_space_wake(
> ASSERT(!xlog_in_recovery(log));
>
> spin_lock(&log->l_reserve_head.lock);
> - free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
> + free_bytes = xlog_grant_space_left(log, &log->l_reserve_head);
> xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
> spin_unlock(&log->l_reserve_head.lock);
> }
> @@ -1237,64 +1294,6 @@ xfs_log_cover(
> return error;
> }
>
> -/*
> - * Return the space in the log between the tail and the head. The head
> - * is passed in the cycle/bytes formal parms. In the special case where
> - * the reserve head has wrapped passed the tail, this calculation is no
> - * longer valid. In this case, just return 0 which means there is no space
> - * in the log. This works for all places where this function is called
> - * with the reserve head. Of course, if the write head were to ever
> - * wrap the tail, we should blow up. Rather than catch this case here,
> - * we depend on other ASSERTions in other parts of the code. XXXmiken
> - *
> - * If reservation head is behind the tail, we have a problem. Warn about it,
> - * but then treat it as if the log is empty.
> - *
> - * If the log is shut down, the head and tail may be invalid or out of whack, so
> - * shortcut invalidity asserts in this case so that we don't trigger them
> - * falsely.
> - */
> -int
> -xlog_space_left(
> - struct xlog *log,
> - atomic64_t *head)
> -{
> - int tail_bytes;
> - int tail_cycle;
> - int head_cycle;
> - int head_bytes;
> -
> - xlog_crack_grant_head(head, &head_cycle, &head_bytes);
> - xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
> - tail_bytes = BBTOB(tail_bytes);
> - if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
> - return log->l_logsize - (head_bytes - tail_bytes);
> - if (tail_cycle + 1 < head_cycle)
> - return 0;
> -
> - /* Ignore potential inconsistency when shutdown. */
> - if (xlog_is_shutdown(log))
> - return log->l_logsize;
> -
> - if (tail_cycle < head_cycle) {
> - ASSERT(tail_cycle == (head_cycle - 1));
> - return tail_bytes - head_bytes;
> - }
> -
> - /*
> - * The reservation head is behind the tail. In this case we just want to
> - * return the size of the log as the amount of space left.
> - */
> - xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
> - xfs_alert(log->l_mp, " tail_cycle = %d, tail_bytes = %d",
> - tail_cycle, tail_bytes);
> - xfs_alert(log->l_mp, " GH cycle = %d, GH bytes = %d",
> - head_cycle, head_bytes);
> - ASSERT(0);
> - return log->l_logsize;
> -}
> -
> -
> static void
> xlog_ioend_work(
> struct work_struct *work)
> @@ -1883,8 +1882,8 @@ xlog_sync(
> if (ticket) {
> ticket->t_curr_res -= roundoff;
> } else {
> - xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
> - xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
> + xlog_grant_add_space(log, &log->l_reserve_head, roundoff);
> + xlog_grant_add_space(log, &log->l_write_head, roundoff);
> }
>
> /* put cycle number in every block */
> @@ -2815,17 +2814,15 @@ xfs_log_ticket_regrant(
> if (ticket->t_cnt > 0)
> ticket->t_cnt--;
>
> - xlog_grant_sub_space(log, &log->l_reserve_head.grant,
> - ticket->t_curr_res);
> - xlog_grant_sub_space(log, &log->l_write_head.grant,
> - ticket->t_curr_res);
> + xlog_grant_sub_space(log, &log->l_reserve_head, ticket->t_curr_res);
> + xlog_grant_sub_space(log, &log->l_write_head, ticket->t_curr_res);
> ticket->t_curr_res = ticket->t_unit_res;
>
> trace_xfs_log_ticket_regrant_sub(log, ticket);
>
> /* just return if we still have some of the pre-reserved space */
> if (!ticket->t_cnt) {
> - xlog_grant_add_space(log, &log->l_reserve_head.grant,
> + xlog_grant_add_space(log, &log->l_reserve_head,
> ticket->t_unit_res);
> trace_xfs_log_ticket_regrant_exit(log, ticket);
>
> @@ -2873,8 +2870,8 @@ xfs_log_ticket_ungrant(
> bytes += ticket->t_unit_res*ticket->t_cnt;
> }
>
> - xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
> - xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
> + xlog_grant_sub_space(log, &log->l_reserve_head, bytes);
> + xlog_grant_sub_space(log, &log->l_write_head, bytes);
>
> trace_xfs_log_ticket_ungrant_exit(log, ticket);
>
> diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
> index 8a005cb08a02..86b5959b5ef2 100644
> --- a/fs/xfs/xfs_log_priv.h
> +++ b/fs/xfs/xfs_log_priv.h
> @@ -571,8 +571,6 @@ xlog_assign_grant_head(atomic64_t *head, int cycle, int space)
> atomic64_set(head, xlog_assign_grant_head_val(cycle, space));
> }
>
> -int xlog_space_left(struct xlog *log, atomic64_t *head);
> -
> /*
> * Committed Item List interfaces
> */
> --
> 2.36.1
>
