btrfs: Output ENOSPC debug info in inc_block_group_ro

Since inc_block_group_ro() would return -ENOSPC, outputting debug info
for enospc_debug mount option would be helpful to debug some balance
false ENOSPC report.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2f683da..994c71c 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -9605,6 +9605,7 @@ static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
 {
        struct btrfs_space_info *sinfo = cache->space_info;
        u64 num_bytes;
+       u64 sinfo_used;
        u64 min_allocable_bytes;
        int ret = -ENOSPC;
 
@@ -9631,9 +9632,10 @@ static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
 
        num_bytes = cache->key.offset - cache->reserved - cache->pinned -
                    cache->bytes_super - btrfs_block_group_used(&cache->item);
+       sinfo_used = btrfs_space_info_used(sinfo, true);
 
-       if (btrfs_space_info_used(sinfo, true) + num_bytes +
-           min_allocable_bytes <= sinfo->total_bytes) {
+       if (sinfo_used + num_bytes + min_allocable_bytes <=
+           sinfo->total_bytes) {
                sinfo->bytes_readonly += num_bytes;
                cache->ro++;
                list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
@@ -9642,6 +9644,15 @@ static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
 out:
        spin_unlock(&cache->lock);
        spin_unlock(&sinfo->lock);
+       if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) {
+               btrfs_info(cache->fs_info,
+                       "unable to make block group %llu ro",
+                       cache->key.objectid);
+               btrfs_info(cache->fs_info,
+                       "sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu",
+                       sinfo_used, num_bytes, min_allocable_bytes);
+               dump_space_info(cache->fs_info, cache->space_info, 0, 0);
+       }
        return ret;
 }