xfs: merge iop_unpin_remove into iop_unpin

The unpin_remove item operation instances always share most of the
implementation with the respective unpin implementation.  So instead
of keeping two different entry points add a remove flag to the unpin
operation and share the code more easily.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

1 files changed, 28 insertions, 46 deletions

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 711f69abbbe4..93899953c603 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -388,20 +388,25 @@ xfs_buf_item_pin(
  * Also drop the reference to the buf item for the current transaction.
  * If the XFS_BLI_STALE flag is set and we are the last reference,
  * then free up the buf log item and unlock the buffer.
+ *
+ * If the remove flag is set we are called from uncommit in the
+ * forced-shutdown path.  If that is true and the reference count on
+ * the log item is going to drop to zero we need to free the item's
+ * descriptor in the transaction.
  */
 STATIC void
 xfs_buf_item_unpin(
-        xfs_buf_log_item_t      *bip)
+        xfs_buf_log_item_t      *bip,
+        int                     remove)
 {
         struct xfs_ail  *ailp;
-        xfs_buf_t       *bp;
+        xfs_buf_t       *bp = bip->bli_buf;
         int             freed;
         int             stale = bip->bli_flags & XFS_BLI_STALE;
 
-        bp = bip->bli_buf;
-        ASSERT(bp != NULL);
         ASSERT(XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *) == bip);
         ASSERT(atomic_read(&bip->bli_refcount) > 0);
+
         trace_xfs_buf_item_unpin(bip);
 
         freed = atomic_dec_and_test(&bip->bli_refcount);
@@ -413,8 +418,26 @@ xfs_buf_item_unpin(
                 ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
                 ASSERT(XFS_BUF_ISSTALE(bp));
                 ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
+
                 trace_xfs_buf_item_unpin_stale(bip);
 
+                if (remove) {
+                        /*
+                         * We have to remove the log item from the transaction
+                         * as we are about to release our reference to the
+                         * buffer.  If we don't, the unlock that occurs later
+                         * in xfs_trans_uncommit() will ry to reference the
+                         * buffer which we no longer have a hold on.
+                         */
+                        xfs_trans_del_item(&bip->bli_item);
+
+                        /*
+                         * Since the transaction no longer refers to the buffer,
+                         * the buffer should no longer refer to the transaction.
+                         */
+                        XFS_BUF_SET_FSPRIVATE2(bp, NULL);
+                }
+
                 /*
                  * If we get called here because of an IO error, we may
                  * or may not have the item on the AIL. xfs_trans_ail_delete()
@@ -436,45 +459,6 @@ xfs_buf_item_unpin(
 }
 
 /*
- * this is called from uncommit in the forced-shutdown path.
- * we need to check to see if the reference count on the log item
- * is going to drop to zero.  If so, unpin will free the log item
- * so we need to free the item's descriptor (that points to the item)
- * in the transaction.
- */
-STATIC void
-xfs_buf_item_unpin_remove(
-        xfs_buf_log_item_t      *bip,
-        xfs_trans_t             *tp)
-{
-        /* will xfs_buf_item_unpin() call xfs_buf_item_relse()? */
-        if ((atomic_read(&bip->bli_refcount) == 1) &&
-            (bip->bli_flags & XFS_BLI_STALE)) {
-                /*
-                 * yes -- We can safely do some work here and then call
-                 * buf_item_unpin to do the rest because we are
-                 * are holding the buffer locked so no one else will be
-                 * able to bump up the refcount. We have to remove the
-                 * log item from the transaction as we are about to release
-                 * our reference to the buffer. If we don't, the unlock that
-                 * occurs later in the xfs_trans_uncommit() will try to
-                 * reference the buffer which we no longer have a hold on.
-                 */
-                ASSERT(XFS_BUF_VALUSEMA(bip->bli_buf) <= 0);
-                trace_xfs_buf_item_unpin_stale(bip);
-
-                xfs_trans_del_item(&bip->bli_item);
-
-                /*
-                 * Since the transaction no longer refers to the buffer, the
-                 * buffer should no longer refer to the transaction.
-                 */
-                XFS_BUF_SET_FSPRIVATE2(bip->bli_buf, NULL);
-        }
-        xfs_buf_item_unpin(bip);
-}
-
-/*
  * This is called to attempt to lock the buffer associated with this
  * buf log item.  Don't sleep on the buffer lock.  If we can't get
  * the lock right away, return 0.  If we can get the lock, take a
@@ -669,9 +653,7 @@ static struct xfs_item_ops xfs_buf_item_ops = {
         .iop_format     = (void(*)(xfs_log_item_t*, xfs_log_iovec_t*))
                                         xfs_buf_item_format,
         .iop_pin        = (void(*)(xfs_log_item_t*))xfs_buf_item_pin,
-        .iop_unpin      = (void(*)(xfs_log_item_t*))xfs_buf_item_unpin,
-        .iop_unpin_remove = (void(*)(xfs_log_item_t*, xfs_trans_t *))
-                                        xfs_buf_item_unpin_remove,
+        .iop_unpin      = (void(*)(xfs_log_item_t*, int))xfs_buf_item_unpin,
         .iop_trylock    = (uint(*)(xfs_log_item_t*))xfs_buf_item_trylock,
         .iop_unlock     = (void(*)(xfs_log_item_t*))xfs_buf_item_unlock,
         .iop_committed  = (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))