Btrfs: add balance progress reporting

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 35 insertions, 4 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c32667318ae4..d73439b4d7da 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2441,6 +2441,7 @@ static u64 div_factor(u64 num, int factor)
 
 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 {
+        struct btrfs_balance_control *bctl = fs_info->balance_ctl;
         struct btrfs_root *chunk_root = fs_info->chunk_root;
         struct btrfs_root *dev_root = fs_info->dev_root;
         struct list_head *devices;
@@ -2456,6 +2457,7 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
         int slot;
         int ret;
         int enospc_errors = 0;
+        bool counting = true;
 
         /* step one make some room on all the devices */
         devices = &fs_info->fs_devices->devices;
@@ -2487,12 +2489,18 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
                 ret = -ENOMEM;
                 goto error;
         }
+
+        /* zero out stat counters */
+        spin_lock(&fs_info->balance_lock);
+        memset(&bctl->stat, 0, sizeof(bctl->stat));
+        spin_unlock(&fs_info->balance_lock);
+again:
         key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
         key.offset = (u64)-1;
         key.type = BTRFS_CHUNK_ITEM_KEY;
 
         while (1) {
-                if (atomic_read(&fs_info->balance_pause_req) ||
+                if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
                     atomic_read(&fs_info->balance_cancel_req)) {
                         ret = -ECANCELED;
                         goto error;
@@ -2529,24 +2537,47 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 
                 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
 
+                if (!counting) {
+                        spin_lock(&fs_info->balance_lock);
+                        bctl->stat.considered++;
+                        spin_unlock(&fs_info->balance_lock);
+                }
+
                 ret = should_balance_chunk(chunk_root, leaf, chunk,
                                            found_key.offset);
                 btrfs_release_path(path);
                 if (!ret)
                         goto loop;
 
+                if (counting) {
+                        spin_lock(&fs_info->balance_lock);
+                        bctl->stat.expected++;
+                        spin_unlock(&fs_info->balance_lock);
+                        goto loop;
+                }
+
                 ret = btrfs_relocate_chunk(chunk_root,
                                            chunk_root->root_key.objectid,
                                            found_key.objectid,
                                            found_key.offset);
                 if (ret && ret != -ENOSPC)
                         goto error;
-                if (ret == -ENOSPC)
+                if (ret == -ENOSPC) {
                         enospc_errors++;
+                } else {
+                        spin_lock(&fs_info->balance_lock);
+                        bctl->stat.completed++;
+                        spin_unlock(&fs_info->balance_lock);
+                }
 loop:
                 key.offset = found_key.offset - 1;
         }
 
+        if (counting) {
+                btrfs_release_path(path);
+                counting = false;
+                goto again;
+        }
 error:
         btrfs_free_path(path);
         if (enospc_errors) {
@@ -2576,7 +2607,7 @@ static void __cancel_balance(struct btrfs_fs_info *fs_info)
         BUG_ON(ret);
 }
 
-void update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
+void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
                                struct btrfs_ioctl_balance_args *bargs);
 
 /*
@@ -2706,7 +2737,7 @@ do_balance:
 
         if (bargs) {
                 memset(bargs, 0, sizeof(*bargs));
-                update_ioctl_balance_args(fs_info, bargs);
+                update_ioctl_balance_args(fs_info, 0, bargs);
         }
 
         if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||