Commit Graph

4 Commits

Author SHA1 Message Date
Adam Simpkins
b4527fe5bb simplify InodePtr classes
Summary:
This simplifies the InodePtrImpl class by removing support for pointer-to-const
Inode objects.  We don't currently use pointer-to-const Inode objects, and I
don't really anticipate that we will ever need this.

The primary motivating factor behind this diff is a recent change in clang that
breaks the existing code: clang PR31606 prevents children classes from
inheriting template constructor instantiations from their parent which take a
reference to the parent class type as the only argument.

While this could have been fixed by explicitly defining the necessary
constructors in the child class (or simply by overriding newPtrLocked() and
newPtrFromExisting() to return the subclass type), dropping support for
pointer-to-const allows us to simplify the code and resolve this issue.

Reviewed By: wez

Differential Revision: D4825526

fbshipit-source-id: 999de352788b13818b7f23788bb34686e193cd5d
2017-04-06 13:20:01 -07:00
Wez Furlong
4235784907 add .eden "magic" dir
Summary:
It's not really magic because we don't have a virtual directory
inode base any more.  Instead, we mkdir and populate it at mount time.

What is slightly magical about it is that we give it some special powers:

* We know the inode number of the eden dir and prevent unlink operations
  on it or inside it.
* The .eden dir is present in the contents of the root inode and will
  show up when that directory is `readdir`'d
* When resolving a child of a TreeInode by name, we know to return the
  magic `.eden` inode number.  This means that it is possible to `stat`
  and consume the `.eden` directory from any directory inside the eden
  mount, even though it won't show up in `readdir` for those child dirs.

The contents of the `.eden` dir are:

* `socket` - a symlink back to the unix domain socket that our thrift
  server is listening on.  This means that it is a simple
  `readlink(".eden/socket")` operation to discover both whether a directory
  is part of an eden mount and how to talk to the server.

* `root` - a symlink back to the root of this eden mount.  This allows
  using `readlink(".eden/root")` as a simple 1-step operation to find
  the root of an eden mount, and avoids needing to walk up directory
  by directory as is the common pattern for locating `.hg` or `.git`
  dirs.

Reviewed By: simpkins

Differential Revision: D4637285

fbshipit-source-id: 0eabf98b29144acccef5c83bd367493399dc55bb
2017-03-24 23:07:42 -07:00
Adam Simpkins
251da81f36 update all copyright statements to "2016-present"
Summary:
Update copyright statements to "2016-present".  This makes our updated lint
rules happy and complies with the recommended license header statement.

Reviewed By: wez, bolinfest

Differential Revision: D4433594

fbshipit-source-id: e9ecb1c1fc66e4ec49c1f046c6a98d425b13bc27
2017-01-20 22:03:02 -08:00
Adam Simpkins
3a73253057 add new InodePtr classes
Summary:
This defines our own custom smart pointer type for Inode objects.  This will
provide us with more control over Inode lifetime, allowing us to decide if we
want to unload them immediately when they become unreferenced, or keep them
around for a while.

This will also allow us to fix some memory management issues around EdenMount
destruction.  Currently we destroy the EdenMount immediately when it is
unmounted.  This can cause issues if other parts of the code are still holding
references to Inode objects from this EdenMount.  Our custom InodePtr class
will also allow us to delay destroying the EdenMount until all of its Inodes
have been destroyed.

This diff adds the new pointer types and updates the code to use them, but does
not actually implement destroying unreferenced inodes yet.  The logic for that
has proven to be slightly subtle; I will split it out into its own separate
diff.

Reviewed By: wez

Differential Revision: D4351072

fbshipit-source-id: 7a9d81cbd226c9662a79a2f2ceda82fe2651f312
2017-01-17 15:03:20 -08:00