Pinning an MFS folder takes a lot of IO

### Checklist

- [X] This is a bug report, not a question. Ask questions on [discuss.ipfs.io](https://discuss.ipfs.io).
- [X] I have searched on the [issue tracker](https://github.com/ipfs/go-ipfs/issues?q=is%3Aissue) for my bug.
- [X] I am running the latest [go-ipfs version](https://dist.ipfs.io/#go-ipfs) or have an issue updating.

### Installation method

built from source

### Version

```Text
go-ipfs version: 0.14.0-dev-a72753bad-dirty
Repo version: 12
System version: amd64/linux
Golang version: go1.18.2
```

### Config

```json
{
"API": {
"HTTPHeaders": {}
},
"Addresses": {
"API": "/ip4/127.0.0.1/tcp/5001",
"Announce": [],
"AppendAnnounce": null,
"Gateway": "/ip4/127.0.0.1/tcp/80",
"NoAnnounce": [
"/ip4/10.0.0.0/ipcidr/8",
"/ip4/100.64.0.0/ipcidr/10",
"/ip4/169.254.0.0/ipcidr/16",
"/ip4/172.16.0.0/ipcidr/12",
"/ip4/192.0.0.0/ipcidr/24",
"/ip4/192.0.0.0/ipcidr/29",
"/ip4/192.0.0.8/ipcidr/32",
"/ip4/192.0.0.170/ipcidr/32",
"/ip4/192.0.0.171/ipcidr/32",
"/ip4/192.0.2.0/ipcidr/24",
"/ip4/192.168.0.0/ipcidr/16",
"/ip4/198.18.0.0/ipcidr/15",
"/ip4/198.51.100.0/ipcidr/24",
"/ip4/203.0.113.0/ipcidr/24",
"/ip4/240.0.0.0/ipcidr/4",
"/ip6/100::/ipcidr/64",
"/ip6/2001:2::/ipcidr/48",
"/ip6/2001:db8::/ipcidr/32",
"/ip6/fc00::/ipcidr/7",
"/ip6/fe80::/ipcidr/10"
],
"Swarm": [
"/ip4/0.0.0.0/tcp/443",
"/ip6/::/tcp/443",
"/ip4/0.0.0.0/udp/443/quic",
"/ip6/::/udp/443/quic"
]
},
"AutoNAT": {
"ServiceMode": "disabled"
},
"Bootstrap": [
"/dnsaddr/bootstrap.libp2p.io/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN",
"/dnsaddr/bootstrap.libp2p.io/p2p/QmQCU2EcMqAqQPR2i9bChDtGNJchTbq5TbXJJ16u19uLTa",
"/dnsaddr/bootstrap.libp2p.io/p2p/QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb",
"/dnsaddr/bootstrap.libp2p.io/p2p/QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt",
"/ip4/104.131.131.82/tcp/4001/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ",
"/ip4/104.131.131.82/udp/4001/quic/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ"
],
"DNS": {
"Resolvers": null
},
"Datastore": {
"BloomFilterSize": 0,
"GCPeriod": "1h",
"HashOnRead": false,
"Spec": {
"mounts": [
{
"child": {
"path": "blocks",
"shardFunc": "/repo/flatfs/shard/v1/next-to-last/2",
"sync": false,
"type": "flatfs"
},
"mountpoint": "/blocks",
"prefix": "flatfs.datastore",
"type": "measure"
},
{
"child": {
"compression": "none",
"path": "datastore",
"type": "levelds"
},
"mountpoint": "/",
"prefix": "leveldb.datastore",
"type": "measure"
}
],
"type": "mount"
},
"StorageGCWatermark": 90,
"StorageMax": "500GB"
},
"Discovery": {
"MDNS": {
"Enabled": false,
"Interval": 10
}
},
"Experimental": {
"AcceleratedDHTClient": true,
"FilestoreEnabled": false,
"GraphsyncEnabled": false,
"Libp2pStreamMounting": false,
"P2pHttpProxy": false,
"StrategicProviding": false,
"UrlstoreEnabled": false
},
"Gateway": {
"APICommands": [],
"HTTPHeaders": {
"Access-Control-Allow-Headers": [
"X-Requested-With",
"Range",
"User-Agent"
],
"Access-Control-Allow-Methods": [
"GET"
],
"Access-Control-Allow-Origin": [
"*"
]
},
"NoDNSLink": false,
"NoFetch": false,
"PathPrefixes": [],
"PublicGateways": null,
"RootRedirect": "",
"Writable": false
},
"Identity": {
"PeerID": "QmVoV4RiGLcxAfhA181GXR867bzVxmRTWwaubvhUyFrBwB"
},
"Internal": {
"Bitswap": {
"EngineBlockstoreWorkerCount": 4,
"EngineTaskWorkerCount": 2,
"TaskWorkerCount": 4
},
"UnixFSShardingSizeThreshold": "1MB"
},
"Ipns": {
"RecordLifetime": "4h",
"RepublishPeriod": "15m",
"ResolveCacheSize": 2048,
"UsePubsub": true
},
"Migration": {
"DownloadSources": null,
"Keep": ""
},
"Mounts": {
"FuseAllowOther": false,
"IPFS": "/ipfs",
"IPNS": "/ipns"
},
"Peering": {
"Peers": null
},
"Pinning": {},
"Plugins": {
"Plugins": null
},
"Provider": {
"Strategy": ""
},
"Pubsub": {
"DisableSigning": false,
"Enabled": true,
"Router": "gossipsub"
},
"Reprovider": {
"Interval": "12h",
"Strategy": "all"
},
"Routing": {
"Type": "dht"
},
"Swarm": {
"AddrFilters": [
"/ip4/10.0.0.0/ipcidr/8",
"/ip4/100.64.0.0/ipcidr/10",
"/ip4/169.254.0.0/ipcidr/16",
"/ip4/172.16.0.0/ipcidr/12",
"/ip4/192.0.0.0/ipcidr/24",
"/ip4/192.0.0.0/ipcidr/29",
"/ip4/192.0.0.8/ipcidr/32",
"/ip4/192.0.0.170/ipcidr/32",
"/ip4/192.0.0.171/ipcidr/32",
"/ip4/192.0.2.0/ipcidr/24",
"/ip4/192.168.0.0/ipcidr/16",
"/ip4/198.18.0.0/ipcidr/15",
"/ip4/198.51.100.0/ipcidr/24",
"/ip4/203.0.113.0/ipcidr/24",
"/ip4/240.0.0.0/ipcidr/4",
"/ip6/100::/ipcidr/64",
"/ip6/2001:2::/ipcidr/48",
"/ip6/2001:db8::/ipcidr/32",
"/ip6/fc00::/ipcidr/7",
"/ip6/fe80::/ipcidr/10"
],
"ConnMgr": {
"GracePeriod": "3m",
"HighWater": 1200,
"LowWater": 600,
"Type": "basic"
},
"DisableBandwidthMetrics": false,
"DisableNatPortMap": true,
"EnableHolePunching": false,
"RelayClient": {
"Enabled": false
},
"RelayService": {
"ConnectionDataLimit": 268435456,
"ConnectionDurationLimit": "24h",
"Enabled": true,
"MaxCircuits": 100,
"MaxReservations": 1024,
"MaxReservationsPerASN": 100,
"MaxReservationsPerIP": 1,
"MaxReservationsPerPeer": 1
},
"Transports": {
"Multiplexers": {},
"Network": {},
"Security": {}
}
}
}
```

### Description

I'm using ipfs-cluster on an ipfs node with around 500 GB data in the MFS in a lot of smallish files.

I do update the files with normal `ipfs files` operations like `ipfs files rm` and `ipfs files cp`.

Afterwards the folder is added to the clusterpin, so the already fully stored MFS folder is then pinned locally again, by the ipfs-cluster-daemon.

I run the `ipfs-cluster-ctl pin update $oldcid $newcid` command for this, to only push the data to cluster members which already hold the old pin, to avoid shuffling the 60-100 GB folders around in the cluster.

The "null" pin operation takes a very long time and creates a lot of reading IO – for no apparent benefit. The data is already stored in the MFS and would just need to be marked as "pinned" additionally, without checking each and every block for existence (or whatever IPFS does in this case).

I see loads of up to 60 on the machine:

```
Log in to system : odin.pacman.store
Operating system : ArchLinux
Kernel version : 5.17.5-arch1-1
No. processors : 10
Main memory : 32104M
Machine load : 53,91, 58,76, 61,60
Machine uptime : 13 days 6:54
```






# What I tried to work around this:

I reduced the IO priority of the ipfs daemon in the systemd unit file:

```
IOSchedulingClass=idle
IOSchedulingPriority=1
```

This made the system more responsive again.

I changed the bitswap internal values to the following:

```
"Bitswap": {
"EngineBlockstoreWorkerCount": 4,
"EngineTaskWorkerCount": 2,
"TaskWorkerCount": 4
},
```

Overall, this doesn't really help (if it does do anything (yet)).

(The graphs above are already with these changes)

Edit: Just to confirm: The GC is *not* running. I invoke the GC manually when necessary.