WIP Use preload tests to test pmemfile-fuse.

[mslusarz]

This change is 

[codecov]

Codecov Report

Merging #437 into master will increase coverage by 1.72%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #437      +/-   ##
==========================================
+ Coverage    78.9%   80.63%   +1.72%     
==========================================
  Files          71       71              
  Lines        8809     8809              
  Branches     1774     1774              
==========================================
+ Hits         6951     7103     +152     
+ Misses       1409     1207     -202     
- Partials      449      499      +50

Flag	Coverage Δ
#ltp_tests	45.69% <ø> (+0.18%)	⬆️
#sqlite_tests	45.69% <ø> (+0.01%)	⬆️
#tests_antool	15.06% <ø> (ø)	⬆️
#tests_fuse	30.85% <ø> (?)
#tests_posix_multi_threaded	25.32% <ø> (+0.01%)	⬆️
#tests_posix_single_threaded	57.02% <ø> (+0.02%)	⬆️
#tests_preload	44.88% <ø> (+0.2%)	⬆️

Impacted Files	Coverage Δ
src/libpmemfile-posix/offset_mapping.c	85% <0%> (-1.43%)	⬇️
src/libpmemfile-posix/rename.c	91.09% <0%> (-0.81%)	⬇️
src/libpmemfile-posix/data.c	94.48% <0%> (-0.4%)	⬇️
src/libpmemfile-posix/dir.c	90.19% <0%> (ø)	⬆️
src/libpmemfile/preload.c	51.42% <0%> (+0.15%)	⬆️
src/libpmemfile-posix/inode.c	89.07% <0%> (+0.33%)	⬆️
src/libpmemfile-posix/getdents.c	90.96% <0%> (+0.64%)	⬆️
src/pmemfile-fuse/main.c	49.35% <0%> (+49.35%)	⬆️

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[mslusarz]

I'm puzzled why "preload_nested_dirs" fails on Travis with this PR. It passes locally and I can't see anything in the patch that could affect this test. It fails randomly when test tries to create many directories (https://github.com/mslusarz/pmemfile/blob/fuse/tests/preload/nested_dirs/nested_dirs.cmake#L82 ).

@GBuella ideas?

[GBuella]

/pmemfile-fedora-25/tests/helpers.cmake(151):  execute(mkdir /tmp/pmemfile-tests//nested_dirs/mount_point/test_dir/a/b/c/d/e/f/g/x43 )
/pmemfile-fedora-25/tests/helpers.cmake(102):  execute_process(COMMAND mkdir /tmp/pmemfile-tests//nested_dirs/mount_point/test_dir/a/b/c/d/e/f/g/x43 RESULT_VARIABLE res )
mkdir: cannot create directory '/tmp/pmemfile-tests//nested_dirs/mount_point/test_dir/a/b/c/d/e/f/g/x43': Input/output error

I found only a single place in code where we return EIO: when libpmemfile does not manage to open a pool. Perhaps some more logging, to find out why it can't open the pool sometimes.

[krzycz]

Reviewed 17 of 21 files at r1.
Review status: 17 of 21 files reviewed at latest revision, all discussions resolved, some commit checks failed.

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Comments from Reviewable

[krzycz]

Reviewed 4 of 21 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved, some commit checks failed.

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Comments from Reviewable