* store: proxy: add test for deadlocking problem

Signed-off-by: Giedrius Statkevičius <giedriuswork@gmail.com>

* store: proxy: add fix for timeouts

Checking here if the series context has ended is the correct fix here.
We want to check it because if any of the other Series() calls error out
then the context is canceled. So, it is equal to checking for errors
"downstream", in `mergedSeriesSet`.

Also, `handleErr()` here is the correct function to use because in such
a case we want to set `s.err` -- if `io.EOF` still hasn't been received
then it means that StoreAPI still has some data that it wants to send
but hasn't yet.

With this, the previously added test passes.

Signed-off-by: Giedrius Statkevičius <giedriuswork@gmail.com>

Co-authored-by: Giedrius Statkevičius <giedriuswork@gmail.com>

Related to: #2459

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

Fixes: #2471

This commit fixes an issue where multiple goroutines in the block
fetcher filtering were concurrently accessing the same map. The
goroutines were concurrently writing AND reading to the shared metas
map. This commit guards this concurrent access by giving the
DeduplicateFilter struct a mutex.

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

Fixes #2459 (quick fix).

This keeps the logic from the 0.11.0 which was good enough.

Some improvement for future: #2470

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

Signed-off-by: yeya24 <yb532204897@gmail.com>
Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

Co-authored-by: yeya24 <yb532204897@gmail.com>

Merge v0.12.1 into master

Signed-off-by: Marco Pracucci <marco@pracucci.com>

Signed-off-by: Marco Pracucci <marco@pracucci.com>

Signed-off-by: Marco Pracucci <marco@pracucci.com>