In the Current bug we were re-using the context
from previously granted lockers, this would
lead to lock timeouts for existing valid
read or write locks, leading to premature
timeout of locks.
This bug affects only local lockers in FS
or standalone erasure coded mode. This issue
is rather historical as well and was present
in lsync for some time but we were lucky to
not see it.
Similar changes are done in dsync as well
to keep the code more familiar
Fixes#9827
At a customer setup with lots of concurrent calls
it can be observed that in newRetryTimer there
were lots of tiny alloations which are not
relinquished upon retries, in this codepath
we were only interested in re-using the timer
and use it wisely for each locker.
```
(pprof) top
Showing nodes accounting for 8.68TB, 97.02% of 8.95TB total
Dropped 1198 nodes (cum <= 0.04TB)
Showing top 10 nodes out of 79
flat flat% sum% cum cum%
5.95TB 66.50% 66.50% 5.95TB 66.50% time.NewTimer
1.16TB 13.02% 79.51% 1.16TB 13.02% github.com/ncw/directio.AlignedBlock
0.67TB 7.53% 87.04% 0.70TB 7.78% github.com/minio/minio/cmd.xlObjects.putObject
0.21TB 2.36% 89.40% 0.21TB 2.36% github.com/minio/minio/cmd.(*posix).Walk
0.19TB 2.08% 91.49% 0.27TB 2.99% os.statNolog
0.14TB 1.59% 93.08% 0.14TB 1.60% os.(*File).readdirnames
0.10TB 1.09% 94.17% 0.11TB 1.25% github.com/minio/minio/cmd.readDirN
0.10TB 1.07% 95.23% 0.10TB 1.07% syscall.ByteSliceFromString
0.09TB 1.03% 96.27% 0.09TB 1.03% strings.(*Builder).grow
0.07TB 0.75% 97.02% 0.07TB 0.75% path.(*lazybuf).append
```
enable linter using golangci-lint across
codebase to run a bunch of linters together,
we shall enable new linters as we fix more
things the codebase.
This PR fixes the first stage of this
cleanup.
Some tests take a long time on CI:
* `--- PASS: TestRWMutex (226.49s)`
* ` --- PASS: TestRWMutex (7.13s)`
Reduce the number of runs.
Before/after locally:
```
--- PASS: TestRWMutex (20.95s)
--- PASS: TestRWMutex (7.13s)
--- PASS: TestMutex (3.01s)
--- PASS: TestMutex (1.65s)
```
Change distributed locking to allow taking bulk locks
across objects, reduces usually 1000 calls to 1.
Also allows for situations where multiple clients sends
delete requests to objects with following names
```
{1,2,3,4,5}
```
```
{5,4,3,2,1}
```
will block and ensure that we do not fail the request
on each other.
This PR implements locking from a global entity into
a more localized set level entity, allowing for locks
to be held only on the resources which are writing
to a collection of disks rather than a global level.
In this process this PR also removes the top-level
limit of 32 nodes to an unlimited number of nodes. This
is a precursor change before bring in bucket expansion.
Harshavardhana