fe4f7940d2
The kernel threads are currently stopped and destroyed synchronously by gfs2_make_fs_ro() and gfs2_put_super(), and asynchronously by signal_our_withdraw(), with no synchronization, so the synchronous and asynchronous contexts can race with each other. First, when creating the kernel threads, take an extra task struct reference so that the task struct won't go away immediately when they terminate. This allows those kthreads to terminate immediately when they're done rather than hanging around as zombies until they are reaped by kthread_stop(). When kthread_stop() is called on a terminated kthread, it will return immediately. Second, in signal_our_withdraw(), once the SDF_JOURNAL_LIVE flag has been cleared, wake up the logd and quotad wait queues instead of stopping the logd and quotad kthreads. The kthreads are then expected to terminate automatically within short time, but if they cannot, they will not block the withdraw. For example, if a user process and one of the kthread decide to withdraw at the same time, only one of them will perform the actual withdraw and the other will wait for it to be done. If the kthread ends up being the one to wait, the withdrawing user process won't be able to stop it. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> |
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.