On Wed, 2025-01-29 at 11:07 +0100, Andreas Schwab wrote: > The statx06 test in the LTP testsuite fails since the multigrain > timestamp feature was merged: > > https://openqa.opensuse.org/tests/4800409#step/statx06/7 > > The issue is that the nsec part of ctime does not change from the time > the file is created: > > $ touch xx > $ stat -c $'mtime %y\nctime %z' xx > mtime 2025-01-29 09:43:44.677442605 +0100 > ctime 2025-01-29 09:43:44.677442605 +0100 > $ touch xx > $ stat -c $'mtime %y\nctime %z' xx > mtime 2025-01-29 09:43:51.641581658 +0100 > ctime 2025-01-29 09:43:51.677442605 +0100 > > My guess would be that something in inode_set_ctime_current is going > wrong. > Thanks for the bug report, Andreas. I assume you're seeing this across different filesystems (i.e. tmpfs, ext4, etc.)? It almost looks like this try_cmpxchg() is returning true without actually doing the swap: if (try_cmpxchg(&inode->i_ctime_nsec, &cur, now.tv_nsec)) { /* If swap occurred, then we're (mostly) done */ inode->i_ctime_sec = now.tv_sec; trace_ctime_ns_xchg(inode, cns, now.tv_nsec, cur); mgtime_counter_inc(mg_ctime_swaps); } else { It might also be interesting to see the output of that tracepoint over this test, if you're able. Thanks, -- Jeff Layton <jlayton@xxxxxxxxxx>
