71bddbccab
While running a new fstest that races a readonly remount with scrub running in repair mode, I observed the kernel tripping over debugging assertions in the log quiesce code that were checking that the CIL was empty. When the sysadmin runs scrub in repair mode, the scrub code allocates real transactions (with reservations) to change things, but doesn't increment the superblock writers count to block a readonly remount attempt while it is running. We don't require the userspace caller to have a writable file descriptor to run repairs, so we have to call mnt_want_write_file to obtain freeze protection and increment the writers count. It's ok to remove the call to sb_start_write for the dry-run case because commit 8321ddb2fa29 removed the behavior where scrub and fsfreeze fight over the buffer LRU. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
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.