[PATCH 5/8] xfs: factor and move some code in xfs_log_cil.c

Dave Chinner
2022-04-27T02:23:08Z

From: Dave Chinner <dchinner@redhat.com>

In preparation for adding support for intent item whiteouts.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_log_cil.c | 119 ++++++++++++++++++++++++-------------------
1 file changed, 67 insertions(+), 52 deletions(-)

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index e5ab62f08c19..0d8d092447ad 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -47,6 +47,38 @@ xlog_cil_ticket_alloc(
return tic;
}

+/*
+ * Check if the current log item was first committed in this sequence.
+ * We can't rely on just the log item being in the CIL, we have to check
+ * the recorded commit sequence number.
+ *
+ * Note: for this to be used in a non-racy manner, it has to be called with
+ * CIL flushing locked out. As a result, it should only be used during the
+ * transaction commit process when deciding what to format into the item.
+ */
+static bool
+xlog_item_in_current_chkpt(
+ struct xfs_cil *cil,
+ struct xfs_log_item *lip)
+{
+ if (list_empty(&lip->li_cil))
+ return false;
+
+ /*
+ * li_seq is written on the first commit of a log item to record the
+ * first checkpoint it is written to. Hence if it is different to the
+ * current sequence, we're in a new checkpoint.
+ */
+ return lip->li_seq == READ_ONCE(cil->xc_current_sequence);
+}
+
+bool
+xfs_log_item_in_current_chkpt(
+ struct xfs_log_item *lip)
+{
+ return xlog_item_in_current_chkpt(lip->li_log->l_cilp, lip);
+}
+
/*
* Unavoidable forward declaration - xlog_cil_push_work() calls
* xlog_cil_ctx_alloc() itself.
@@ -934,6 +966,40 @@ xlog_cil_build_trans_hdr(
tic->t_curr_res -= lvhdr->lv_bytes;
}

+/*
+ * Pull all the log vectors off the items in the CIL, and remove the items from
+ * the CIL. We don't need the CIL lock here because it's only needed on the
+ * transaction commit side which is currently locked out by the flush lock.
+ */
+static void
+xlog_cil_build_lv_chain(
+ struct xfs_cil *cil,
+ struct xfs_cil_ctx *ctx,
+ uint32_t *num_iovecs,
+ uint32_t *num_bytes)
+{
+ struct xfs_log_vec *lv = NULL;
+
+ while (!list_empty(&cil->xc_cil)) {
+ struct xfs_log_item *item;
+
+ item = list_first_entry(&cil->xc_cil,
+ struct xfs_log_item, li_cil);
+ list_del_init(&item->li_cil);
+ if (!ctx->lv_chain)
+ ctx->lv_chain = item->li_lv;
+ else
+ lv->lv_next = item->li_lv;
+ lv = item->li_lv;
+ item->li_lv = NULL;
+ *num_iovecs += lv->lv_niovecs;
+
+ /* we don't write ordered log vectors */
+ if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED)
+ *num_bytes += lv->lv_bytes;
+ }
+}
+
/*
* Push the Committed Item List to the log.
*
@@ -956,7 +1022,6 @@ xlog_cil_push_work(
container_of(work, struct xfs_cil_ctx, push_work);
struct xfs_cil *cil = ctx->cil;
struct xlog *log = cil->xc_log;
- struct xfs_log_vec *lv;
struct xfs_cil_ctx *new_ctx;
int num_iovecs = 0;
int num_bytes = 0;
@@ -1033,31 +1098,7 @@ xlog_cil_push_work(
list_add(&ctx->committing, &cil->xc_committing);
spin_unlock(&cil->xc_push_lock);

- /*
- * Pull all the log vectors off the items in the CIL, and remove the
- * items from the CIL. We don't need the CIL lock here because it's only
- * needed on the transaction commit side which is currently locked out
- * by the flush lock.
- */
- lv = NULL;
- while (!list_empty(&cil->xc_cil)) {
- struct xfs_log_item *item;
-
- item = list_first_entry(&cil->xc_cil,
- struct xfs_log_item, li_cil);
- list_del_init(&item->li_cil);
- if (!ctx->lv_chain)
- ctx->lv_chain = item->li_lv;
- else
- lv->lv_next = item->li_lv;
- lv = item->li_lv;
- item->li_lv = NULL;
- num_iovecs += lv->lv_niovecs;
-
- /* we don't write ordered log vectors */
- if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED)
- num_bytes += lv->lv_bytes;
- }
+ xlog_cil_build_lv_chain(cil, ctx, &num_iovecs, &num_bytes);

/*
* Switch the contexts so we can drop the context lock and move out
@@ -1508,32 +1549,6 @@ xlog_cil_force_seq(
return 0;
}

-/*
- * Check if the current log item was first committed in this sequence.
- * We can't rely on just the log item being in the CIL, we have to check
- * the recorded commit sequence number.
- *
- * Note: for this to be used in a non-racy manner, it has to be called with
- * CIL flushing locked out. As a result, it should only be used during the
- * transaction commit process when deciding what to format into the item.
- */
-bool
-xfs_log_item_in_current_chkpt(
- struct xfs_log_item *lip)
-{
- struct xfs_cil *cil = lip->li_log->l_cilp;
-
- if (list_empty(&lip->li_cil))
- return false;
-
- /*
- * li_seq is written on the first commit of a log item to record the
- * first checkpoint it is written to. Hence if it is different to the
- * current sequence, we're in a new checkpoint.
- */
- return lip->li_seq == READ_ONCE(cil->xc_current_sequence);
-}
-
/*
* Perform initial CIL structure initialisation.
*/
--
2.35.1