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
-
Wayland 1.24 Released with Fixes and New Features
Wayland continues to move forward, while X11 slowly vanishes into the shadows, and the latest release includes plenty of improvements.
-
Bugs Found in sudo
Two critical flaws allow users to gain access to root privileges.
-
Fedora Continues 32-Bit Support
In a move that should come as a relief to some portions of the Linux community, Fedora will continue supporting 32-bit architecture.
-
Linux Kernel 6.17 Drops bcachefs
After a clash over some late fixes and disagreements between bcachefs's lead developer and Linus Torvalds, bachefs is out.
-
ONLYOFFICE v9 Embraces AI
Like nearly all office suites on the market (except LibreOffice), ONLYOFFICE has decided to go the AI route.
-
Two Local Privilege Escalation Flaws Discovered in Linux
Qualys researchers have discovered two local privilege escalation vulnerabilities that allow hackers to gain root privileges on major Linux distributions.
-
New TUXEDO InfinityBook Pro Powered by AMD Ryzen AI 300
The TUXEDO InfinityBook Pro 14 Gen10 offers serious power that is ready for your business, development, or entertainment needs.
-
LibreOffice Tested as Possible Office 365 Alternative
Another major organization has decided to test the possibility of migrating from Microsoft's Office 365 to LibreOffice.
-
Linux Mint 20 Reaches EOL
With Linux Mint 20 at its end of life, the time has arrived to upgrade to Linux Mint 22.
-
TuxCare Announces Support for AlmaLinux 9.2
Thanks to TuxCare, AlmaLinux 9.2 (and soon version 9.6) now enjoys years of ongoing patching and compliance.