be78ff0e72
Eryu Guan reported seeing occasional hangs when running generic/269 with a new fsstress that supports clonerange/deduperange. The cause of this hang is an infinite loop when we convert the CoW fork extents from unwritten to real just prior to writing the pages out; the infinite loop happens because there's nothing in the CoW fork to convert, and so it spins forever. The fundamental issue here is that when we go to perform these CoW fork conversions, we're supposed to have an extent waiting for us, but the low space CoW reaper has snuck in and blown them away! There are four conditions that can dissuade the reaper from touching our file -- no reflink iflag; dirty page cache; writeback in progress; or directio in progress. We check the four conditions prior to taking the locks, but we neglect to recheck them once we have the locks, which is how we end up whacking the writeback that's in progress. Therefore, refactor the four checks into a helper function and call it once again once we have the locks to make sure we really want to reap the inode. While we're at it, add an ASSERT for this weird condition so that we'll fail noisily if we ever screw this up again. Reported-by: Eryu Guan <eguan@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Tested-by: Eryu Guan <eguan@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> |
||
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.