xfs: cancel dfops on xfs_defer_finish() error

The current semantics of xfs_defer_finish() require the caller to
call xfs_defer_cancel() on error. This is slightly inconsistent with
transaction commit error handling where a failed commit cleans up
the transaction before returning.

More significantly, the only requirement for exposure of
->dop_pending outside of xfs_defer_finish() is so that
xfs_defer_cancel() can drain it on error. Since the only recourse of
xfs_defer_finish() errors is cancellation, mirror the transaction
logic and cancel remaining dfops before returning from
xfs_defer_finish() with an error.

Beside simplifying xfs_defer_finish() semantics, this ensures that
xfs_defer_finish() always returns with an empty ->dop_pending and
thus facilitates removal of the list from xfs_defer_ops.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

8 files changed, 21 insertions, 24 deletions

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 3190dfc21b60..1e671d4eb6fa 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -590,7 +590,7 @@ xfs_attr_leaf_addname(
                         goto out_defer_cancel;
                 error = xfs_defer_finish(&args->trans);
                 if (error)
-                        goto out_defer_cancel;
+                        return error;
 
                 /*
                  * Commit the current trans (including the inode) and start
@@ -678,7 +678,7 @@ xfs_attr_leaf_addname(
                                 goto out_defer_cancel;
                         error = xfs_defer_finish(&args->trans);
                         if (error)
-                                goto out_defer_cancel;
+                                return error;
                 }
 
                 /*
@@ -741,7 +741,7 @@ xfs_attr_leaf_removename(
                         goto out_defer_cancel;
                 error = xfs_defer_finish(&args->trans);
                 if (error)
-                        goto out_defer_cancel;
+                        return error;
         }
         return 0;
 out_defer_cancel:
@@ -867,7 +867,7 @@ restart:
                                 goto out_defer_cancel;
                         error = xfs_defer_finish(&args->trans);
                         if (error)
-                                goto out_defer_cancel;
+                                goto out;
 
                         /*
                          * Commit the node conversion and start the next
@@ -891,7 +891,7 @@ restart:
                         goto out_defer_cancel;
                 error = xfs_defer_finish(&args->trans);
                 if (error)
-                        goto out_defer_cancel;
+                        goto out;
         } else {
                 /*
                  * Addition succeeded, update Btree hashvals.
@@ -987,7 +987,7 @@ restart:
                                 goto out_defer_cancel;
                         error = xfs_defer_finish(&args->trans);
                         if (error)
-                                goto out_defer_cancel;
+                                goto out;
                 }
 
                 /*
@@ -1110,7 +1110,7 @@ xfs_attr_node_removename(
                         goto out_defer_cancel;
                 error = xfs_defer_finish(&args->trans);
                 if (error)
-                        goto out_defer_cancel;
+                        goto out;
                 /*
                  * Commit the Btree join operation and start a new trans.
                  */
@@ -1141,7 +1141,7 @@ xfs_attr_node_removename(
                                 goto out_defer_cancel;
                         error = xfs_defer_finish(&args->trans);
                         if (error)
-                                goto out_defer_cancel;
+                                goto out;
                 } else
                         xfs_trans_brelse(args->trans, bp);
         }
diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
index f52552313773..af094063e402 100644
--- a/fs/xfs/libxfs/xfs_attr_remote.c
+++ b/fs/xfs/libxfs/xfs_attr_remote.c
@@ -488,7 +488,7 @@ xfs_attr_rmtval_set(
                         goto out_defer_cancel;
                 error = xfs_defer_finish(&args->trans);
                 if (error)
-                        goto out_defer_cancel;
+                        return error;
 
                 ASSERT(nmap == 1);
                 ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
@@ -628,7 +628,7 @@ xfs_attr_rmtval_remove(
                         goto out_defer_cancel;
                 error = xfs_defer_finish(&args->trans);
                 if (error)
-                        goto out_defer_cancel;
+                        return error;
 
                 /*
                  * Close out trans and start the next one in the chain.
diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
index 7079f534c735..b656a399cd71 100644
--- a/fs/xfs/libxfs/xfs_defer.c
+++ b/fs/xfs/libxfs/xfs_defer.c
@@ -416,14 +416,15 @@ xfs_defer_finish_noroll(
         }
 
 out:
-        if (error)
+        if (error) {
                 trace_xfs_defer_finish_error((*tp)->t_mountp, (*tp)->t_dfops,
                                              error);
-         else
-                trace_xfs_defer_finish_done((*tp)->t_mountp, (*tp)->t_dfops,
-                                            _RET_IP_);
+                xfs_defer_cancel(*tp);
+                return error;
+        }
 
-        return error;
+        trace_xfs_defer_finish_done((*tp)->t_mountp, (*tp)->t_dfops, _RET_IP_);
+        return 0;
 }
 
 int
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 30ac1300dc49..d9dad399440a 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1624,7 +1624,7 @@ xfs_swap_extent_rmap(
                         error = xfs_defer_finish(tpp);
                         tp = *tpp;
                         if (error)
-                                goto out_defer;
+                                goto out;
 
                         tirec.br_startoff += rlen;
                         if (tirec.br_startblock != HOLESTARTBLOCK &&
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index e1196854dbcd..70a76ac41f01 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -371,7 +371,7 @@ xfs_dquot_disk_alloc(
         tp = *tpp;
         if (error) {
                 xfs_buf_relse(bp);
-                goto error1;
+                goto error0;
         }
         *bpp = bp;
         return 0;
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 7bb46a0eecfc..d957a46dc1cb 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1571,7 +1571,7 @@ xfs_itruncate_extents_flags(
                  */
                 error = xfs_defer_finish(&tp);
                 if (error)
-                        goto out_bmap_cancel;
+                        goto out;
 
                 error = xfs_trans_roll_inode(&tp, ip);
                 if (error)
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index dce8ba8ab681..2ec562d75494 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -518,10 +518,8 @@ xfs_reflink_cancel_cow_blocks(
 
                         /* Roll the transaction */
                         error = xfs_defer_finish(tpp);
-                        if (error) {
-                                xfs_defer_cancel(*tpp);
+                        if (error)
                                 break;
-                        }
 
                         /* Remove the mapping from the CoW fork. */
                         xfs_bmap_del_extent_cow(ip, &icur, &got, &del);
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index b0130b21f4de..b050663c2a70 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -933,10 +933,8 @@ __xfs_trans_commit(
                      !(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
         if (!regrant && (tp->t_flags & XFS_TRANS_PERM_LOG_RES)) {
                 error = xfs_defer_finish_noroll(&tp);
-                if (error) {
-                        xfs_defer_cancel(tp);
+                if (error)
                         goto out_unreserve;
-                }
         }
 
         /*