2391245ac2
When flushing space we join a transaction to flush delayed items and delayed references, in order to try to release space. However using btrfs_join_transaction() not only joins an existing transaction as well as it starts a new transaction if there is none open. If there is no transaction open, we don't have neither delayed items nor delayed references, so creating a new transaction is a waste of time, IO and creates an unnecessary rotation of the backup roots without gaining any benefits (including releasing space). So use btrfs_join_transaction_nostart() when attempting to flush delayed items and references. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.