Based on discussions at LSFMM, on where are we at with automatic fs suspend / resume. I did a quick check and most of the complexities from the last series I tried from 2023-03 [0] are now resolved, namely the following patches are no longer needed as Christian did the work for this already: fs: unify locking semantics for fs freeze / thaw fs: distinguish between user initiated freeze and kernel initiated freeze fs: move !SB_BORN check early on freeze and add for thaw So the only thing left to do is add an fs flag for a sanity check that the fs doesn't use rely on ktrhead freezing, and enable it for filesystems which have done that work. This adds the work for a few filesystems. If regressions are found we can simply remove FS_AUTOFREEZE from the fs. I did a quick boot test with this on my laptop and suspend doesn't work, its not clear if this was an artifact of me trying this on linux-next or what, I can try without my patches on next to see if next actually suspends without them. And so, we gotta figure out if there's something stupid still to fix, or something broken with these changes I overlooked on the rebase. [0] https://web.git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=20230507-fs-freeze Luis Chamberlain (6): fs: add frozen sb state helpers fs: add iterate_supers_excl() and iterate_supers_reverse_excl() fs: add automatic kernel fs freeze / thaw and remove kthread freezing ext4: replace kthread freezing with auto fs freezing btrfs: replace kthread freezing with auto fs freezing xfs: replace kthread freezing with auto fs freezing fs/btrfs/disk-io.c | 4 +- fs/btrfs/scrub.c | 2 +- fs/btrfs/super.c | 2 +- fs/ext4/ext4_jbd2.c | 2 +- fs/ext4/mballoc.c | 2 +- fs/ext4/super.c | 9 +-- fs/gfs2/sys.c | 2 +- fs/quota/quota.c | 3 +- fs/super.c | 149 +++++++++++++++++++++++++++++++++++++++-- fs/xfs/xfs_discard.c | 2 +- fs/xfs/xfs_log.c | 3 +- fs/xfs/xfs_log_cil.c | 2 +- fs/xfs/xfs_mru_cache.c | 2 +- fs/xfs/xfs_pwork.c | 2 +- fs/xfs/xfs_super.c | 16 ++--- fs/xfs/xfs_trans.c | 3 +- fs/xfs/xfs_trans_ail.c | 3 - fs/xfs/xfs_zone_gc.c | 2 - include/linux/fs.h | 38 +++++++++++ kernel/power/process.c | 15 ++++- 20 files changed, 223 insertions(+), 40 deletions(-) -- 2.47.2
