089f4eb003
During direct reads and writes, the caller is holding the inode glock in deferred mode, which doesn't allow metadata updates. However, a previous change caused callers to update the inode modification time before carrying out direct writes, which caused the inode glock to be converted to exclusive mode for the timestamp update, only to be immediately converted back to deferred mode for the direct write. This locks out other direct readers and writers and wreaks havoc on performance. Fix that by reverting to not updating the inode modification time for direct writes. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.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.