Merge branch 'topic/misc' into for-linus

[firefly-linux-kernel-4.4.55.git] / fs / xfs / xfs_log_cil.c

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 9b21f80f31ce70d44d566c2efa8d75b6d2abe358..bb17cc044bf37c994dbf877292ecaf36aa3842fb 100644 (file)
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -199,6 +199,15 @@ xlog_cil_insert(
        list_move_tail(&item->li_cil, &cil->xc_cil);
        ctx->nvecs += diff_iovecs;
 
+       /*
+        * If this is the first time the item is being committed to the CIL,
+        * store the sequence number on the log item so we can tell
+        * in future commits whether this is the first checkpoint the item is
+        * being committed into.
+        */
+       if (!item->li_seq)
+               item->li_seq = ctx->sequence;
+
        /*
         * Now transfer enough transaction reservation to the context ticket
         * for the checkpoint. The context ticket is special - the unit
@@ -325,6 +334,10 @@ xlog_cil_free_logvec(
  * For more specific information about the order of operations in
  * xfs_log_commit_cil() please refer to the comments in
  * xfs_trans_commit_iclog().
+ *
+ * Called with the context lock already held in read mode to lock out
+ * background commit, returns without it held once background commits are
+ * allowed again.
  */
 int
 xfs_log_commit_cil(
@@ -678,3 +691,35 @@ restart:
        spin_unlock(&cil->xc_cil_lock);
        return commit_lsn;
 }
+
+/*
+ * 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_ctx *ctx;
+
+       if (!(lip->li_mountp->m_flags & XFS_MOUNT_DELAYLOG))
+               return false;
+       if (list_empty(&lip->li_cil))
+               return false;
+
+       ctx = lip->li_mountp->m_log->l_cilp->xc_ctx;
+
+       /*
+        * 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.
+        */
+       if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0)
+               return false;
+       return true;
+}