xfs: factor out the CIL transaction header building

It is static code deep in the middle of the CIL push logic. Factor
it out into a helper so that it is clear and easy to modify
separately.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index ba57323bfdcea38d0c02cc308c43260cd89d5e29..93f966c191a3d3a330015461d0402c4ec4f8cd0b 100644 (file)
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -868,6 +868,41 @@ xlog_cil_write_commit_record(
        return error;
 }
 
+struct xlog_cil_trans_hdr {
+       struct xfs_trans_header thdr;
+       struct xfs_log_iovec    lhdr;
+};
+
+/*
+ * Build a checkpoint transaction header to begin the journal transaction.  We
+ * need to account for the space used by the transaction header here as it is
+ * not accounted for in xlog_write().
+ */
+static void
+xlog_cil_build_trans_hdr(
+       struct xfs_cil_ctx      *ctx,
+       struct xlog_cil_trans_hdr *hdr,
+       struct xfs_log_vec      *lvhdr,
+       int                     num_iovecs)
+{
+       struct xlog_ticket      *tic = ctx->ticket;
+
+       memset(hdr, 0, sizeof(*hdr));
+
+       hdr->thdr.th_magic = XFS_TRANS_HEADER_MAGIC;
+       hdr->thdr.th_type = XFS_TRANS_CHECKPOINT;
+       hdr->thdr.th_tid = tic->t_tid;
+       hdr->thdr.th_num_items = num_iovecs;
+       hdr->lhdr.i_addr = &hdr->thdr;
+       hdr->lhdr.i_len = sizeof(xfs_trans_header_t);
+       hdr->lhdr.i_type = XLOG_REG_TYPE_TRANSHDR;
+       tic->t_curr_res -= hdr->lhdr.i_len + sizeof(struct xlog_op_header);
+
+       lvhdr->lv_niovecs = 1;
+       lvhdr->lv_iovecp = &hdr->lhdr;
+       lvhdr->lv_next = ctx->lv_chain;
+}
+
 /*
  * Push the Committed Item List to the log.
  *
@@ -892,11 +927,9 @@ xlog_cil_push_work(
        struct xlog             *log = cil->xc_log;
        struct xfs_log_vec      *lv;
        struct xfs_cil_ctx      *new_ctx;
-       struct xlog_ticket      *tic;
        int                     num_iovecs;
        int                     error = 0;
-       struct xfs_trans_header thdr;
-       struct xfs_log_iovec    lhdr;
+       struct xlog_cil_trans_hdr thdr;
        struct xfs_log_vec      lvhdr = { NULL };
        xfs_csn_t               push_seq;
        bool                    push_commit_stable;
@@ -1025,24 +1058,8 @@ xlog_cil_push_work(
         * Build a checkpoint transaction header and write it to the log to
         * begin the transaction. We need to account for the space used by the
         * transaction header here as it is not accounted for in xlog_write().
-        *
-        * The LSN we need to pass to the log items on transaction commit is
-        * the LSN reported by the first log vector write. If we use the commit
-        * record lsn then we can move the tail beyond the grant write head.
         */
-       tic = ctx->ticket;
-       thdr.th_magic = XFS_TRANS_HEADER_MAGIC;
-       thdr.th_type = XFS_TRANS_CHECKPOINT;
-       thdr.th_tid = tic->t_tid;
-       thdr.th_num_items = num_iovecs;
-       lhdr.i_addr = &thdr;
-       lhdr.i_len = sizeof(xfs_trans_header_t);
-       lhdr.i_type = XLOG_REG_TYPE_TRANSHDR;
-       tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t);
-
-       lvhdr.lv_niovecs = 1;
-       lvhdr.lv_iovecp = &lhdr;
-       lvhdr.lv_next = ctx->lv_chain;
+       xlog_cil_build_trans_hdr(ctx, &thdr, &lvhdr, num_iovecs);
 
        error = xlog_cil_write_chain(ctx, &lvhdr);
        if (error)
@@ -1052,7 +1069,7 @@ xlog_cil_push_work(
        if (error)
                goto out_abort_free_ticket;
 
-       xfs_log_ticket_ungrant(log, tic);
+       xfs_log_ticket_ungrant(log, ctx->ticket);
 
        /*
         * If the checkpoint spans multiple iclogs, wait for all previous iclogs
@@ -1116,7 +1133,7 @@ out_skip:
        return;
 
 out_abort_free_ticket:
-       xfs_log_ticket_ungrant(log, tic);
+       xfs_log_ticket_ungrant(log, ctx->ticket);
        ASSERT(xlog_is_shutdown(log));
        if (!ctx->commit_iclog) {
                xlog_cil_committed(ctx);