https://bugzilla.kernel.org/show_bug.cgi?id=194739 Bug ID: 194739 Summary: fallocate --collapse-range causes temporal data corruption on fragmented file Product: File System Version: 2.5 Kernel Version: 4.10.1 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: ext4 Assignee: fs_ext4@xxxxxxxxxxxxxxxxxxxx Reporter: iive@xxxxxxxxx Regression: No I use `fallocate -c` to cut the start of the file without having to copy the whole file again. However recently, after collapsing the file it seems to repeat a portion of the data, that should have been moved. That is, the new start of the file is found somewhere around its old location. Restarting the computer (or just hibernate) seems to fix the file. Doing: `echo 3 > /proc/sys/vm/drop_caches` also seems to fix the issue. Using just `echo 1` fixes some of the data, but the file still might be broken. I've noticed this problem on 4.9 kernel. I'm not sure if it is regression, because the problem might be triggered by high fragmentation. This partition got quite full and the files are quite big, thus they are always very fragmented. Just want to make it clear. Data on disk is not damaged. -- You are receiving this mail because: You are watching the assignee of the bug.
