btrfs: qgroup: show more meaningful qgroup_rescan_init error message

Error message from qgroup_rescan_init() mostly looks like:

  BTRFS info (device nvme0n1p1): qgroup_rescan_init failed with -115

Which is far from meaningful, and sometimes confusing as for above
-EINPROGRESS it's mostly (despite the init race) harmless, but sometimes
it can also indicate problem if the return value is -EINVAL.

Change it to some more meaningful messages like:

  BTRFS info (device nvme0n1p1): qgroup rescan is already in progress

And

  BTRFS err(device nvme0n1p1): qgroup rescan init failed, qgroup is not enabled

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
[ update the messages and level ]
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 18 insertions, 15 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 457219d6a16b..1874a6d2e6f5 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2782,26 +2782,36 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 {
         int ret = 0;
 
-        if (!init_flags &&
-            (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
-             !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
-                ret = -EINVAL;
-                goto err;
+        if (!init_flags) {
+                /* we're resuming qgroup rescan at mount time */
+                if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN))
+                        btrfs_warn(fs_info,
+                        "qgroup rescan init failed, qgroup is not enabled");
+                else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
+                        btrfs_warn(fs_info,
+                        "qgroup rescan init failed, qgroup rescan is not queued");
+                return -EINVAL;
         }
 
         mutex_lock(&fs_info->qgroup_rescan_lock);
         spin_lock(&fs_info->qgroup_lock);
 
         if (init_flags) {
-                if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
+                if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
+                        btrfs_warn(fs_info,
+                                   "qgroup rescan is already in progress");
                         ret = -EINPROGRESS;
-                else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
+                } else if (!(fs_info->qgroup_flags &
+                             BTRFS_QGROUP_STATUS_FLAG_ON)) {
+                        btrfs_warn(fs_info,
+                        "qgroup rescan init failed, qgroup is not enabled");
                         ret = -EINVAL;
+                }
 
                 if (ret) {
                         spin_unlock(&fs_info->qgroup_lock);
                         mutex_unlock(&fs_info->qgroup_rescan_lock);
-                        goto err;
+                        return ret;
                 }
                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
         }
@@ -2820,13 +2830,6 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
         btrfs_init_work(&fs_info->qgroup_rescan_work,
                         btrfs_qgroup_rescan_helper,
                         btrfs_qgroup_rescan_worker, NULL, NULL);
-
-        if (ret) {
-err:
-                btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
-                return ret;
-        }
-
         return 0;
 }