The locking can fail in a couple of ways:
- A concurrent fread from an unbuffered or line-buffered file flushes
the output of other line-buffered files, and if _fwalk locks every
file, then the fread blocks until other file reads have completed.
- __sfp can initialize a file lock while _fwalk is locking/unlocking it.
For now, revert to the behavior Bionic had in previous releases. This
commit reverts the file locking parts of commit
468efc80da.
Bug: http://b/131251441
Bug: http://b/130189834
Test: bionic unit tests
Change-Id: I9e20b9cd8ccd14e7962f7308e174f08af72b56c6
c485cdb024