Zack's Kernel News
Zack's Kernel News

Chronicler Zack Brown reports on the latest news, views, dilemmas, and developments within the Linux kernel community.
Protecting Filesystems from Themselves
Chao Yu recently tried to revert a kernel commit for an F2FS patch. F2FS is a Samsung filesystem for solid state drives. Chao wanted to revert the patch because one of the kernel's generic tests expected F2FS to fail to mount a read-only partition. Ironically, as pointed out by Jaegeuk Kim, F2FS had no trouble mounting such a partition and giving the user full read access to all its data. So the filesystem failed the test … because it succeeded.
Jaegeuk suggested changing the test rather than reverting the patch, but Chao pointed out that the test was actually important for filesystems in general, not just F2FS. Changing the test for that one case, he said, would mean other filesystems might technically pass the test when they really should fail.
Chao also disagreed with Jaegeuk that F2FS handled the case properly. Walking through the code, he identified a certain point at which, he said, the device was then read-only, so that all writes would fail. Therefore, recovered data would not be able to persist beyond the expiration of the page cache. At that point, he said, the user would see stale data instead of the latest system state.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
Linux Mint 22.2 Beta Available for Testing
Some interesting new additions and improvements are coming to Linux Mint. Check out the Linux Mint 22.2 Beta to give it a test run.
-
Debian 13.0 Officially Released
After two years of development, the latest iteration of Debian is now available with plenty of under-the-hood improvements.
-
Upcoming Changes for MXLinux
MXLinux 25 has plenty in store to please all types of users.
-
A New Linux AI Assistant in Town
Newelle, a Linux AI assistant, works with different LLMs and includes document parsing and profiles.
-
Linux Kernel 6.16 Released with Minor Fixes
The latest Linux kernel doesn't really include any big-ticket features, just a lot of lines of code.
-
EU Sovereign Tech Fund Gains Traction
OpenForum Europe recently released a report regarding a sovereign tech fund with backing from several significant entities.
-
FreeBSD Promises a Full Desktop Installer
FreeBSD has lacked an option to include a full desktop environment during installation.
-
Linux Hits an Important Milestone
If you pay attention to the news in the Linux-sphere, you've probably heard that the open source operating system recently crashed through a ceiling no one thought possible.
-
Plasma Bigscreen Returns
A developer discovered that the Plasma Bigscreen feature had been sitting untouched, so he decided to do something about it.
-
CachyOS Now Lets Users Choose Their Shell
Imagine getting the opportunity to select which shell you want during the installation of your favorite Linux distribution. That's now a thing.