636d91d7ee
The purpose of the BUG_ON is not clear. The helper btrfs_grab_root()
could return a NULL in case args->root would be a NULL or if there are
zero references. Then we check if the root pointer stored in the inode
still exists.
The whole call chain is for iget:
btrfs_iget
btrfs_iget_path
btrfs_iget_locked
iget5_locked
btrfs_init_locked_inode
which is called from many contexts where we the root pointer is used and
we can safely assume has enough references.
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.