Darrick J. Wong poked me about the status of the fs freez work, he's right, it's been too long since the last spin. The last v2 attempt happened in April 2021 [0], this just takes the feedback from Christoph and spins it again. I've only done basic build tests on x86_64, and haven't yet run time tested the stuff, but given the size of this set its better to review early before getting stuck on details. So this is what I've ended up with so far. Please help me paint the bike shed, and figure out the stuff perhaps I had not considered yet. The locking stuff is really the important thing here. I'd like to re-iterate that tons of areas of the kernel are using the kthread freezer stuff for things it probably has no reason to use it, so once we remove this from the fs, it should be easy to start trimming this from other parts of the kernel. The kthread freezer stuff was put in place originally stop IO in flight for fs. Other parts of the kernels should have no business using this stuff after all this work is done. [0] https://lore.kernel.org/all/20210417001026.23858-1-mcgrof@xxxxxxxxxx/ Changes since the last v2: * instead of having different semantics for lock / unlocked freeze and thaw calls, this unifies the semantics by requiring the lock prior to freeze / thaw * uses grab_active_super() now in all all places which need to freeze or thaw, this includes filesystems, this is to match the locking requirements, and so to not add new heuristics over defining if the superblock might be in a good state for freeze/thaw. * drops SB_FREEZE_COMPLETE_AUTO in favor of just checking for a flag to be able to determine if userspace initiated the freeze or if its auto (by the kernel pm) * folded the pm calls for the VFS so that instead of one call which has a one-liner with two routines, we use the same one-liner on the pm side of things. * split the FS stuff by using a enw temporary flag, so to enable easier review of the FS changes * more filesystems use the freezer API now so this also converts them over * adjusted the coccinelle rule to use the new flag and in the end removes it This is all here too: https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=20231010-fs-freeze-v5 Luis Chamberlain (24): fs: unify locking semantics for fs freeze / thaw fs: add frozen sb state helpers fs: distinguish between user initiated freeze and kernel initiated freeze fs: add iterate_supers_excl() and iterate_supers_reverse_excl() fs: add automatic kernel fs freeze / thaw and remove kthread freezing xfs: replace kthread freezing with auto fs freezing btrfs: replace kthread freezing with auto fs freezing ext4: replace kthread freezing with auto fs freezing f2fs: replace kthread freezing with auto fs freezing cifs: replace kthread freezing with auto fs freezing gfs2: replace kthread freezing with auto fs freezing jfs: replace kthread freezing with auto fs freezing nilfs2: replace kthread freezing with auto fs freezing nfs: replace kthread freezing with auto fs freezing nfsd: replace kthread freezing with auto fs freezing ubifs: replace kthread freezing with auto fs freezing ksmbd: replace kthread freezing with auto fs freezing jffs2: replace kthread freezing with auto fs freezing jbd2: replace kthread freezing with auto fs freezing coredump: drop freezer usage ecryptfs: replace kthread freezing with auto fs freezing fscache: replace kthread freezing with auto fs freezing lockd: replace kthread freezing with auto fs freezing fs: remove FS_AUTOFREEZE block/bdev.c | 9 +- fs/btrfs/disk-io.c | 4 +- fs/btrfs/scrub.c | 2 +- fs/cifs/cifsfs.c | 10 +- fs/cifs/connect.c | 8 -- fs/cifs/dfs_cache.c | 2 +- fs/coredump.c | 2 +- fs/ecryptfs/kthread.c | 1 - fs/ext4/ext4_jbd2.c | 2 +- fs/ext4/super.c | 3 - fs/f2fs/gc.c | 12 +- fs/f2fs/segment.c | 6 +- fs/fscache/main.c | 2 +- fs/gfs2/glock.c | 6 +- fs/gfs2/glops.c | 2 +- fs/gfs2/log.c | 2 - fs/gfs2/main.c | 4 +- fs/gfs2/quota.c | 2 - fs/gfs2/super.c | 11 +- fs/gfs2/sys.c | 12 +- fs/gfs2/util.c | 7 +- fs/ioctl.c | 14 ++- fs/jbd2/journal.c | 54 ++++----- fs/jffs2/background.c | 3 +- fs/jfs/jfs_logmgr.c | 11 +- fs/jfs/jfs_txnmgr.c | 31 ++---- fs/ksmbd/connection.c | 3 - fs/ksmbd/transport_tcp.c | 2 - fs/lockd/clntproc.c | 1 - fs/lockd/svc.c | 3 - fs/nfs/callback.c | 4 - fs/nfsd/nfssvc.c | 2 - fs/nilfs2/segment.c | 48 ++++---- fs/quota/quota.c | 4 +- fs/super.c | 232 ++++++++++++++++++++++++++++++++------- fs/ubifs/commit.c | 4 - 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 | 14 +-- fs/xfs/xfs_trans.c | 3 +- fs/xfs/xfs_trans_ail.c | 3 - include/linux/fs.h | 53 ++++++++- kernel/power/process.c | 15 ++- 45 files changed, 393 insertions(+), 229 deletions(-) -- 2.35.1
