On Wed, Jun 30, 2021 at 05:21:05PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> Pass the CIL context to xlog_write() rather than a pointer to a LSN
> variable. Only the CIL checkpoint calls to xlog_write() need to know
> about the start LSN of the writes, so rework xlog_write to directly
> write the LSNs into the CIL context structure.
>
> This removes the commit_lsn variable from xlog_cil_push_work(), so
> now we only have to issue the commit record ordering wakeup from
> there.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Thanks for removing the &commit_lsn bit, which made it more difficult to
figure out what was going on.
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> fs/xfs/xfs_log.c | 18 +++++++++------
> fs/xfs/xfs_log_cil.c | 52 ++++++++++++++++++++++++++++++-------------
> fs/xfs/xfs_log_priv.h | 7 ++++--
> 3 files changed, 52 insertions(+), 25 deletions(-)
>
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 559a78f3752d..fd0731cf1cb3 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -898,7 +898,7 @@ xlog_write_unmount_record(
> */
> if (log->l_targ != log->l_mp->m_ddev_targp)
> blkdev_issue_flush(log->l_targ->bt_bdev);
> - return xlog_write(log, &vec, ticket, NULL, NULL, XLOG_UNMOUNT_TRANS);
> + return xlog_write(log, NULL, &vec, ticket, NULL, XLOG_UNMOUNT_TRANS);
> }
>
> /*
> @@ -2391,9 +2391,9 @@ xlog_write_copy_finish(
> int
> xlog_write(
> struct xlog *log,
> + struct xfs_cil_ctx *ctx,
> struct xfs_log_vec *log_vector,
> struct xlog_ticket *ticket,
> - xfs_lsn_t *start_lsn,
> struct xlog_in_core **commit_iclog,
> uint optype)
> {
> @@ -2424,8 +2424,6 @@ xlog_write(
> }
>
> len = xlog_write_calc_vec_length(ticket, log_vector, optype);
> - if (start_lsn)
> - *start_lsn = 0;
> while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
> void *ptr;
> int log_offset;
> @@ -2438,9 +2436,15 @@ xlog_write(
> ASSERT(log_offset <= iclog->ic_size - 1);
> ptr = iclog->ic_datap + log_offset;
>
> - /* Start_lsn is the first lsn written to. */
> - if (start_lsn && !*start_lsn)
> - *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
> + /*
> + * If we have a context pointer, pass it the first iclog we are
> + * writing to so it can record state needed for iclog write
> + * ordering.
> + */
> + if (ctx) {
> + xlog_cil_set_ctx_write_state(ctx, iclog);
> + ctx = NULL;
> + }
>
> /*
> * This loop writes out as many regions as can fit in the amount
> diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
> index 41f44e6e191c..4b6589bbddb5 100644
> --- a/fs/xfs/xfs_log_cil.c
> +++ b/fs/xfs/xfs_log_cil.c
> @@ -631,6 +631,30 @@ xlog_cil_process_committed(
> }
> }
>
> +/*
> +* Record the LSN of the iclog we were just granted space to start writing into.
> +* If the context doesn't have a start_lsn recorded, then this iclog will
> +* contain the start record for the checkpoint. Otherwise this write contains
> +* the commit record for the checkpoint.
> +*/
> +void
> +xlog_cil_set_ctx_write_state(
> + struct xfs_cil_ctx *ctx,
> + struct xlog_in_core *iclog)
> +{
> + struct xfs_cil *cil = ctx->cil;
> + xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn);
> +
> + ASSERT(!ctx->commit_lsn);
> + spin_lock(&cil->xc_push_lock);
> + if (!ctx->start_lsn)
> + ctx->start_lsn = lsn;
> + else
> + ctx->commit_lsn = lsn;
> + spin_unlock(&cil->xc_push_lock);
> +}
> +
> +
> /*
> * Write out the commit record of a checkpoint transaction associated with the
> * given ticket to close off a running log write. Return the lsn of the commit
> @@ -638,26 +662,26 @@ xlog_cil_process_committed(
> */
> static int
> xlog_cil_write_commit_record(
> - struct xlog *log,
> - struct xlog_ticket *ticket,
> - struct xlog_in_core **iclog,
> - xfs_lsn_t *lsn)
> + struct xfs_cil_ctx *ctx,
> + struct xlog_in_core **iclog)
> {
> - struct xfs_log_iovec reg = {
> + struct xlog *log = ctx->cil->xc_log;
> + struct xfs_log_iovec reg = {
> .i_addr = NULL,
> .i_len = 0,
> .i_type = XLOG_REG_TYPE_COMMIT,
> };
> - struct xfs_log_vec vec = {
> + struct xfs_log_vec vec = {
> .lv_niovecs = 1,
> .lv_iovecp = ®,
> };
> - int error;
> + int error;
>
> if (xlog_is_shutdown(log))
> return -EIO;
>
> - error = xlog_write(log, &vec, ticket, lsn, iclog, XLOG_COMMIT_TRANS);
> + error = xlog_write(log, ctx, &vec, ctx->ticket, iclog,
> + XLOG_COMMIT_TRANS);
> if (error)
> xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
> return error;
> @@ -694,7 +718,6 @@ xlog_cil_push_work(
> struct xfs_trans_header thdr;
> struct xfs_log_iovec lhdr;
> struct xfs_log_vec lvhdr = { NULL };
> - xfs_lsn_t commit_lsn;
> xfs_lsn_t push_seq;
> struct bio bio;
> DECLARE_COMPLETION_ONSTACK(bdev_flush);
> @@ -868,8 +891,7 @@ xlog_cil_push_work(
> */
> wait_for_completion(&bdev_flush);
>
> - error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL,
> - XLOG_START_TRANS);
> + error = xlog_write(log, ctx, &lvhdr, tic, NULL, XLOG_START_TRANS);
> if (error)
> goto out_abort_free_ticket;
>
> @@ -907,8 +929,7 @@ xlog_cil_push_work(
> }
> spin_unlock(&cil->xc_push_lock);
>
> - error = xlog_cil_write_commit_record(log, tic, &commit_iclog,
> - &commit_lsn);
> + error = xlog_cil_write_commit_record(ctx, &commit_iclog);
> if (error)
> goto out_abort_free_ticket;
>
> @@ -935,7 +956,6 @@ xlog_cil_push_work(
> * and wake up anyone who is waiting for the commit to complete.
> */
> spin_lock(&cil->xc_push_lock);
> - ctx->commit_lsn = commit_lsn;
> wake_up_all(&cil->xc_commit_wait);
> spin_unlock(&cil->xc_push_lock);
>
> @@ -951,11 +971,11 @@ xlog_cil_push_work(
> * iclog header lsn and compare it to the commit lsn to determine if we
> * need to wait on iclogs or not.
> */
> - if (ctx->start_lsn != commit_lsn) {
> + if (ctx->start_lsn != ctx->commit_lsn) {
> xfs_lsn_t plsn;
>
> plsn = be64_to_cpu(commit_iclog->ic_prev->ic_header.h_lsn);
> - if (plsn && XFS_LSN_CMP(plsn, commit_lsn) < 0) {
> + if (plsn && XFS_LSN_CMP(plsn, ctx->commit_lsn) < 0) {
> /*
> * Waiting on ic_force_wait orders the completion of
> * iclogs older than ic_prev. Hence we only need to wait
> diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
> index 2de9fe62d8ca..2a02ce05b649 100644
> --- a/fs/xfs/xfs_log_priv.h
> +++ b/fs/xfs/xfs_log_priv.h
> @@ -501,8 +501,8 @@ xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes)
>
> void xlog_print_tic_res(struct xfs_mount *mp, struct xlog_ticket *ticket);
> void xlog_print_trans(struct xfs_trans *);
> -int xlog_write(struct xlog *log, struct xfs_log_vec *log_vector,
> - struct xlog_ticket *tic, xfs_lsn_t *start_lsn,
> +int xlog_write(struct xlog *log, struct xfs_cil_ctx *ctx,
> + struct xfs_log_vec *log_vector, struct xlog_ticket *tic,
> struct xlog_in_core **commit_iclog, uint optype);
> void xfs_log_ticket_ungrant(struct xlog *log, struct xlog_ticket *ticket);
> void xfs_log_ticket_regrant(struct xlog *log, struct xlog_ticket *ticket);
> @@ -573,6 +573,9 @@ void xlog_cil_destroy(struct xlog *log);
> bool xlog_cil_empty(struct xlog *log);
> void xlog_cil_commit(struct xlog *log, struct xfs_trans *tp,
> xfs_csn_t *commit_seq, bool regrant);
> +void xlog_cil_set_ctx_write_state(struct xfs_cil_ctx *ctx,
> + struct xlog_in_core *iclog);
> +
>
> /*
> * CIL force routines
> --
> 2.31.1
>
