https://bugzilla.kernel.org/show_bug.cgi?id=43260 Summary: ftruncate locks up when used with direct IO on ext4 Product: File System Version: 2.5 Kernel Version: all above 3.1-rc3 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: ext4 AssignedTo: fs_ext4@xxxxxxxxxxxxxxxxxxxx ReportedBy: ivan@xxxxxxxxxxxxx CC: tytso@xxxxxxx Regression: No Created an attachment (id=73323) --> (https://bugzilla.kernel.org/attachment.cgi?id=73323) Test program to reproduce the lock up Calling ftruncate shortly after submitting a lot of direct IO requests on a file located on ext4 filesystem causes the ftruncate syscall to lock up. Using other filesystems, e.g. xfs, does not exhibit this behavior. This problem can be reproduced on all kernel versions above 3.1-rc3 (3.1-rc3 itself is fine), e.g. on v3.2.14 -- the kernel that is used in the latest Ubuntu LTS release. The attached program can be used to reproduce the problem. It is possible to reproduce the problem by running the program on a temporary ext4 filesystem inside UML, it is also advisable to do so since other syscalls accessing the file system may lock up as well after starting the program. I was able to bisect the problem to this commit: 8c0bec2151a47906bf779c6715a10ce04453ab77. If you plan to be building the user-mode linux kernel for this range of kernel commits, you may need to apply the changes from commit e5f0bdc7840bdb791247cb98dfc1dab6ea6c7da4 which fix the building problem for ARCH=um. Keywords: ext4, ftruncate, direct IO, dio Architecture: amd64 (but likely is architecture-independent) -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
