There was an error in how we validated disk formats,
if one of the disk was formatted and was formatted with
FS would cause confusion and object layer would never
initialize essentially go into an infinite loop.
Validate pre-emptively and also check for FS format
properly.
This is implemented so that the issues like in the
following flow don't affect the behavior of operation.
```
GetObjectInfo()
.... --> Time window for mutation (no lock held)
.... --> Time window for mutation (no lock held)
GetObject()
```
This happens when two simultaneous uploads are made
to the same object the object has returned wrong
info to the client.
Another classic example is "CopyObject" API itself
which reads from a source object and copies to
destination object.
Fixes#3370Fixes#2912
This is needed as explained by @krisis
Lets say we have following errors.
```
[]error{nil, errFileNotFound, errDiskAccessDenied, errDiskAccesDenied}
```
Since the last two errors are filtered, the maximum is nil,
depending on map order.
Let's say we get nil from reduceErr. Clearly at this point
we don't have quorum nodes agreeing about the data and since
GetObject only requires N/2 (Read quorum) and isDiskQuorum
would have returned true. This is problematic and can lead to
undersiable consequences.
Fixes#3298
Disks when are offline for a long period of time, we should
ignore the disk after trying Login upto 5 times.
This is to reduce the network chattiness, this also reduces
the overall time spent on `net.Dial`.
Fixes#3286
In a situation when we have lots of buckets the bootup time
might have slowed down a bit but during this situation the
servers quickly going up and down would be an in-transit state.
Certain calls which do not use quorum like `readXLMetaStat`
might return an error saying `errDiskNotFound` this is returned
in place of expected `errFileNotFound` which leads to an issue
where server doesn't start.
To avoid this situation we need to ignore them as safe values
to be ignored, for the most part these are network related errors.
Fixes#3275
- abstract out instrumentation information.
- use separate lockInstance type that encapsulates the nsMutex, volume,
path and opsID as the frontend or top-level lock object.
In a multipart upload scenario disks going down and coming backup
can lead to certain parts missing on the disk/server which was
going down. This is a valid case since these blocks can be
missing and should be healed through heal operation. But we are
not supposed to fail prematurely since we have enough data on
the other disks as well within read-quorum.
This fix relaxes previous assumption, fixes a major corruption
issue reproduced by @vadmeste.
Fixes#2976
