mds: nudge log for unstable locks after early_reply

mds: nudge log for unstable locks after early_reply

A getattr/lookup can cause a wrlock or xlock to become unstable after a request
(like rename) acquires it but before early reply. The MDS will not nudge the
log in this situation and the getattr/lookup will need to wait for the eventual
journal flush before the lock is released.

Now looks like:

    2025-06-27T19:41:32.043+0000 7f11d21a9640  5 mds.0.log _submit_thread 25185408~2845 : EUpdate rename [metablob 0x1, 3 dirs]
    2025-06-27T19:41:32.043+0000 7f11d99b8640  1 -- [v2:172.21.10.4:6868/56297870,v1:172.21.10.4:6869/56297870] --> [v2:172.21.10.4:6818/999439823,v1:172.21.10.4:6819/999439823] -- osd_op(unknown.0.23:135 2.e 2:7bf7e7b5:::200.00000006:head [write 19584~2865 [fadvise_dontneed] in=2865b] snapc 0=[] ondisk+write+known_if_redirected+full_force+supports_pool_eio e72) -- 0x563e9b730000 con 0x563e9a674800
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (dn xlock x=1 by request(client.4393:20702 nref=6 cr=0x563e9b83ae00)) on [dentry #0x1/a/file [2,head] auth (dn xlock x=1 by request(client.4393:20702 nref=6 cr=0x563e9b83ae00)) (dversion lock w=1 last_client=4393) pv=14558 v=14556 ap=2 ino=0x10000000002 remote_ino=0x0 referent_inode_ptr=(nil) referent_ino=0x0 state=1610612736 | request=1 lock=2 inodepin=1 dirty=1 waiter=0 authpin=1 0x563e95629900]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (dn xlock x=1 by request(client.4393:20702 nref=6 cr=0x563e9b83ae00)) on [dentry #0x1/b/file [2,head] auth NULL (dn xlock x=1 by request(client.4393:20702 nref=6 cr=0x563e9b83ae00)) (dversion lock w=1 last_client=4393) pv=14557 v=14555 ap=2 ino=(nil) remote_ino=0x0 referent_inode_ptr=(nil) referent_ino=0x0 state=1610612736 | request=1 lock=2 inodepin=0 dirty=1 waiter=0 authpin=1 0x563e95629b80]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (dversion lock w=1 last_client=4393) on [dentry #0x1/a/file [2,head] auth (dn xlock x=1 by request(client.4393:20702 nref=6 cr=0x563e9b83ae00)) (dversion lock w=1 last_client=4393) pv=14558 v=14556 ap=2 ino=0x10000000002 remote_ino=0x0 referent_inode_ptr=(nil) referent_ino=0x0 state=1610612736 | request=1 lock=2 inodepin=1 dirty=1 waiter=0 authpin=1 0x563e95629900]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (dversion lock w=1 last_client=4393) on [dentry #0x1/b/file [2,head] auth NULL (dn xlock x=1 by request(client.4393:20702 nref=6 cr=0x563e9b83ae00)) (dversion lock w=1 last_client=4393) pv=14557 v=14555 ap=2 ino=(nil) remote_ino=0x0 referent_inode_ptr=(nil) referent_ino=0x0 state=1610612736 | request=1 lock=2 inodepin=0 dirty=1 waiter=0 authpin=1 0x563e95629b80]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (ifile excl w=1) on [inode 0x10000000001 [...2,head] /b/ auth v29159 pv29165 ap=1 DIRTYPARENT f(v0 m2025-06-27T19:41:32.017971+0000) n(v0 rc2025-06-27T19:41:32.017971+0000 1=0+1) (isnap sync r=1) (inest lock w=1) (ifile excl w=1) (iversion lock w=1 last_client=4393) caps={4393=pAsLsXsFsx/-@955},l=4393 | request=0 lock=4 dirfrag=1 caps=1 dirtyparent=1 dirty=1 authpin=1 0x563e9a6f5080]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (inest lock w=1 dirty) on [inode 0x1 [...2,head] / auth v179 snaprealm=0x563e9a6ce6c0 f(v0 m2025-06-27T19:09:29.187695+0000 2=0+2) n(v45 rc2025-06-27T19:41:31.249722+0000 3=0+3)/n(v0 rc2025-06-27T19:08:43.024940+0000 1=0+1) (isnap sync r=2) (inest lock w=1 dirty) caps={4359=pAsLsXsFs/-@83,4393=pAsLsXsFs/-@1245} | dirtyscattered=1 request=0 lock=2 dirfrag=1 caps=1 openingsnapparents=0 dirty=1 authpin=0 0x563e9a6f4b00]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (inest lock w=1) on [inode 0x10000000001 [...2,head] /b/ auth v29159 pv29165 ap=1 DIRTYPARENT f(v0 m2025-06-27T19:41:32.017971+0000) n(v0 rc2025-06-27T19:41:32.017971+0000 1=0+1) (isnap sync r=1) (inest lock w=1) (ifile excl w=1) (iversion lock w=1 last_client=4393) caps={4393=pAsLsXsFsx/-@955},l=4393 | request=0 lock=4 dirfrag=1 caps=1 dirtyparent=1 dirty=1 authpin=1 0x563e9a6f5080]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (iquiesce lock w=1 last_client=4393) on [inode 0x10000000000 [...2,head] /a/ auth v29161 pv29163 ap=3 DIRTYPARENT f(v0 m2025-06-27T19:41:32.017971+0000 1=1+0) n(v0 rc2025-06-27T19:41:32.017971+0000 2=1+1) (isnap sync r=2) (inest lock w=1) (ifile lock->sync w=1) (iversion lock w=1 last_client=4393) (iquiesce lock w=1 last_client=4393) caps={4359=pAsLsXs/-@109,4393=pAsLsXs/-@955} | request=1 lock=5 dirfrag=1 caps=1 dirtyparent=1 dirty=1 waiter=1 authpin=1 0x563e9a6f5600]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (isnap sync r=1) on [inode 0x10000000001 [...2,head] /b/ auth v29159 pv29165 ap=1 DIRTYPARENT f(v0 m2025-06-27T19:41:32.017971+0000) n(v0 rc2025-06-27T19:41:32.017971+0000 1=0+1) (isnap sync r=1) (inest lock w=1) (ifile excl w=1) (iversion lock w=1 last_client=4393) caps={4393=pAsLsXsFsx/-@955},l=4393 | request=0 lock=4 dirfrag=1 caps=1 dirtyparent=1 dirty=1 authpin=1 0x563e9a6f5080]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (isnap sync r=2) on [inode 0x1 [...2,head] / auth v179 snaprealm=0x563e9a6ce6c0 f(v0 m2025-06-27T19:09:29.187695+0000 2=0+2) n(v45 rc2025-06-27T19:41:31.249722+0000 3=0+3)/n(v0 rc2025-06-27T19:08:43.024940+0000 1=0+1) (isnap sync r=2) (inest lock w=1 dirty) caps={4359=pAsLsXsFs/-@83,4393=pAsLsXsFs/-@1245} | dirtyscattered=1 request=0 lock=2 dirfrag=1 caps=1 openingsnapparents=0 dirty=1 authpin=0 0x563e9a6f4b00]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (iversion lock w=1 last_client=4393) on [inode 0x10000000000 [...2,head] /a/ auth v29161 pv29163 ap=3 DIRTYPARENT f(v0 m2025-06-27T19:41:32.017971+0000 1=1+0) n(v0 rc2025-06-27T19:41:32.017971+0000 2=1+1) (isnap sync r=2) (inest lock w=1) (ifile lock->sync w=1) (iversion lock w=1 last_client=4393) (iquiesce lock w=1 last_client=4393) caps={4359=pAsLsXs/-@109,4393=pAsLsXs/-@955} | request=1 lock=5 dirfrag=1 caps=1 dirtyparent=1 dirty=1 waiter=1 authpin=1 0x563e9a6f5600]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log NO (iversion lock w=1 last_client=4393) on [inode 0x10000000001 [...2,head] /b/ auth v29159 pv29165 ap=1 DIRTYPARENT f(v0 m2025-06-27T19:41:32.017971+0000) n(v0 rc2025-06-27T19:41:32.017971+0000 1=0+1) (isnap sync r=1) (inest lock w=1) (ifile excl w=1) (iversion lock w=1 last_client=4393) caps={4393=pAsLsXsFsx/-@955},l=4393 | request=0 lock=4 dirfrag=1 caps=1 dirtyparent=1 dirty=1 authpin=1 0x563e9a6f5080]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 10 mds.0.locker nudge_log YES (ifile lock->sync w=1) on [inode 0x10000000000 [...2,head] /a/ auth v29161 pv29163 ap=3 DIRTYPARENT f(v0 m2025-06-27T19:41:32.017971+0000 1=1+0) n(v0 rc2025-06-27T19:41:32.017971+0000 2=1+1) (isnap sync r=2) (inest lock w=1) (ifile lock->sync w=1) (iversion lock w=1 last_client=4393) (iquiesce lock w=1 last_client=4393) caps={4359=pAsLsXs/-@109,4393=pAsLsXs/-@955} | request=1 lock=5 dirfrag=1 caps=1 dirtyparent=1 dirty=1 waiter=1 authpin=1 0x563e9a6f5600]
    2025-06-27T19:41:32.043+0000 7f11d99b8640 20 mds.0.locker : request(client.4393:20702 nref=5 cr=0x563e9b83ae00)
    2025-06-27T19:41:32.043+0000 7f11d99b8640 20 mds.0.log _submit_entry EUpdate rename [metablob 0x1, 3 dirs]

Easily reproducible with two ceph-fuse clients. One session doing:

    $ mkdir a b
    $ touch a/file
    $ while true; do mv -v a/file b/file; mv -v b/file a/file; done

and the other

    $ while true; do stat a/file; done

You can observe the rename/stat stalls (up to 5 seconds; MDS tick interval) without this patch.

Fixes: https://tracker.ceph.com/issues/71876
Signed-off-by: Patrick Donnelly <pdonnell@ibm.com>
(cherry picked from commit db5c9dc2e6cc95a8d112c2131e4cac5340ca9dd0)