commit cb6d88f291e51116e5acafa6620be1425db15330
author Chris Suter <csuter@google.com> Tue Apr 13 01:22:07 2021 +0000
committer CQ Bot <commit-bot@chromium.org> Tue Apr 13 01:22:07 2021 +0000
tree c3a18bb7ac3845f2ebeb43f442f17a1faf19dc32
parent 568e8347f3981007b6e17aa8810d3ca18b2d1ecd

[fxfs] Add transaction locks

 + Add support for transaction locks to guard against things such as
   trying to write to the same object at the same time.

 + Add support for associated objects which allow in-memory changes to
   cached values to be made when the mutation is applied.  This is
   currently used to update the cached size for an object.

 + Also adds support for handling dropped transactions which need to
   roll back changes, e.g. reserved allocations need to be unreserved if
   a transaction fails.

 + This changes creation of new transactions so that an error can be
   returned which will mean that we can stop accepting new transactions
   if the journaling system fails somehow.

Some additional work will need to follow to address locks required for
reads.

Change-Id: Iee70938a6b0b39615661693ae4ab1cbb936e845a
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/509939
Commit-Queue: Chris Suter <csuter@google.com>
Reviewed-by: James Sullivan <jfsulliv@google.com>