When running fuse under valgrind and maybe other tools which slows down execution,
the fuse does not release all resources when fusermount -u is executed immediately
after resource usage.
Adding delay before fusermount -u resolves the issue, so this is a timing race.
Reproduce using make check
libfuse issue libfuse/libfuse#647
./fuse-leak-test
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| Check with no valgrind, usually releases...
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getattr '/'
readdir '/'
getattr '/file1'
open '/file1'
read '/file1'
release '/file1'
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| Check with valgrind, usually fail to release, termination race...
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getattr '/'
readdir '/'
getattr '/file1'
open '/file1'
read '/file1'
FAIL: No release!
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| Check with valgrind and sleep before umount, usually releases.. this proves there is a race...
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getattr '/'
readdir '/'
getattr '/file1'
open '/file1'
read '/file1'
release '/file1'