On Sun, Jan 22, 2023 at 09:57:46PM +0800, Xiubo Li wrote:
> Hi Luis,
>
> On 20/01/2023 18:36, Luís Henriques wrote:
> > On Thu, Jan 19, 2023 at 04:27:09PM +0000, Luís Henriques wrote:
> > > On Wed, Dec 21, 2022 at 05:30:31PM +0800, xiubli@xxxxxxxxxx wrote:
> > > > From: Xiubo Li <xiubli@xxxxxxxxxx>
> > > >
> > > > When unmounting it will just wait for the inflight requests to be
> > > > finished, but just before the sessions are closed the kclient still
> > > > could receive the caps/snaps/lease/quota msgs from MDS. All these
> > > > msgs need to hold some inodes, which will cause ceph_kill_sb() failing
> > > > to evict the inodes in time.
> > > >
> > > > If encrypt is enabled the kernel generate a warning when removing
> > > > the encrypt keys when the skipped inodes still hold the keyring:
> > > Finally (sorry for the delay!) I managed to look into the 6.1 rebase. It
> > > does look good, but I started hitting the WARNING added by patch:
> > >
> > > [DO NOT MERGE] ceph: make sure all the files successfully put before unmounting
> > >
> > > This patch seems to be working but I'm not sure we really need the extra
> > OK, looks like I jumped the gun here: I still see the warning with your
> > patch.
> >
> > I've done a quick hack and the patch below sees fix it. But again, it
> > will impact performance. I'll see if I can figure out something else.
> >
> > Cheers,
> > --
> > Luís
> >
> > diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> > index 2cd134ad02a9..bdb4efa0f9f7 100644
> > --- a/fs/ceph/file.c
> > +++ b/fs/ceph/file.c
> > @@ -2988,6 +2988,21 @@ static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
> > return ret;
> > }
> > +static int ceph_flush(struct file *file, fl_owner_t id)
> > +{
> > + struct inode *inode = file_inode(file);
> > + int ret;
> > +
> > + if ((file->f_mode & FMODE_WRITE) == 0)
> > + return 0;
> > +
> > + ret = filemap_write_and_wait(inode->i_mapping);
> > + if (ret)
> > + ret = filemap_check_wb_err(file->f_mapping, 0);
> > +
> > + return ret;
> > +}
> > +
> > const struct file_operations ceph_file_fops = {
> > .open = ceph_open,
> > .release = ceph_release,
> > @@ -3005,4 +3020,5 @@ const struct file_operations ceph_file_fops = {
> > .compat_ioctl = compat_ptr_ioctl,
> > .fallocate = ceph_fallocate,
> > .copy_file_range = ceph_copy_file_range,
> > + .flush = ceph_flush,
> > };
> >
> This will only fix the second crash case in
> https://tracker.ceph.com/issues/58126#note-6, but not the case in
> https://tracker.ceph.com/issues/58126#note-5.
>
> This issue could be triggered with "test_dummy_encryption" and with
> xfstests-dev's generic/124. You can have a try.
OK, thanks. I'll give it a try. BTW, my local reproducer was
generic/132, not generic/124. I'll let you know if I find something.
> Locally I am still reading the code to check why "sync_filesystem(s);"
> couldn't do the same with "ceph_flush" as above.
>
> I am still on holiday these days and I will test this after my back.
Sure, no problem. Enjoy your break!
Cheers,
--
Luís
>
> Thanks
>
>
> > > 'stopping' state. Looking at the code, we've flushed all the workqueues
> > > and done all the waits, so I *think* the sync_filesystem() call should be
> > > enough.
> > >
> > > The other alternative I see would be to add a ->flush() to ceph_file_fops,
> > > where we'd do a filemap_write_and_wait(). But that would probably have a
> > > negative performance impact -- my understand is that it basically means
> > > we'll have sync file closes.
> > >
> > > Cheers,
> > > --
> > > Luís
> > >
> > > > WARNING: CPU: 4 PID: 168846 at fs/crypto/keyring.c:242 fscrypt_destroy_keyring+0x7e/0xd0
> > > > CPU: 4 PID: 168846 Comm: umount Tainted: G S 6.1.0-rc5-ceph-g72ead199864c #1
> > > > Hardware name: Supermicro SYS-5018R-WR/X10SRW-F, BIOS 2.0 12/17/2015
> > > > RIP: 0010:fscrypt_destroy_keyring+0x7e/0xd0
> > > > RSP: 0018:ffffc9000b277e28 EFLAGS: 00010202
> > > > RAX: 0000000000000002 RBX: ffff88810d52ac00 RCX: ffff88810b56aa00
> > > > RDX: 0000000080000000 RSI: ffffffff822f3a09 RDI: ffff888108f59000
> > > > RBP: ffff8881d394fb88 R08: 0000000000000028 R09: 0000000000000000
> > > > R10: 0000000000000001 R11: 11ff4fe6834fcd91 R12: ffff8881d394fc40
> > > > R13: ffff888108f59000 R14: ffff8881d394f800 R15: 0000000000000000
> > > > FS: 00007fd83f6f1080(0000) GS:ffff88885fd00000(0000) knlGS:0000000000000000
> > > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > > CR2: 00007f918d417000 CR3: 000000017f89a005 CR4: 00000000003706e0
> > > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > > > Call Trace:
> > > > <TASK>
> > > > generic_shutdown_super+0x47/0x120
> > > > kill_anon_super+0x14/0x30
> > > > ceph_kill_sb+0x36/0x90 [ceph]
> > > > deactivate_locked_super+0x29/0x60
> > > > cleanup_mnt+0xb8/0x140
> > > > task_work_run+0x67/0xb0
> > > > exit_to_user_mode_prepare+0x23d/0x240
> > > > syscall_exit_to_user_mode+0x25/0x60
> > > > do_syscall_64+0x40/0x80
> > > > entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > > > RIP: 0033:0x7fd83dc39e9b
> > > >
> > > > URL: https://tracker.ceph.com/issues/58126
> > > > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
> > > > ---
> > > >
> > > > V2:
> > > > - Fix it in ceph layer.
> > > >
> > > >
> > > > fs/ceph/caps.c | 3 +++
> > > > fs/ceph/mds_client.c | 5 ++++-
> > > > fs/ceph/mds_client.h | 7 ++++++-
> > > > fs/ceph/quota.c | 3 +++
> > > > fs/ceph/snap.c | 3 +++
> > > > fs/ceph/super.c | 14 ++++++++++++++
> > > > 6 files changed, 33 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
> > > > index 15d9e0f0d65a..e8a53aeb2a8c 100644
> > > > --- a/fs/ceph/caps.c
> > > > +++ b/fs/ceph/caps.c
> > > > @@ -4222,6 +4222,9 @@ void ceph_handle_caps(struct ceph_mds_session *session,
> > > > dout("handle_caps from mds%d\n", session->s_mds);
> > > > + if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED)
> > > > + return;
> > > > +
> > > > /* decode */
> > > > end = msg->front.iov_base + msg->front.iov_len;
> > > > if (msg->front.iov_len < sizeof(*h))
> > > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> > > > index d41ab68f0130..1ad85af49b45 100644
> > > > --- a/fs/ceph/mds_client.c
> > > > +++ b/fs/ceph/mds_client.c
> > > > @@ -4869,6 +4869,9 @@ static void handle_lease(struct ceph_mds_client *mdsc,
> > > > dout("handle_lease from mds%d\n", mds);
> > > > + if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED)
> > > > + return;
> > > > +
> > > > /* decode */
> > > > if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
> > > > goto bad;
> > > > @@ -5262,7 +5265,7 @@ void send_flush_mdlog(struct ceph_mds_session *s)
> > > > void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
> > > > {
> > > > dout("pre_umount\n");
> > > > - mdsc->stopping = 1;
> > > > + mdsc->stopping = CEPH_MDSC_STOPPING_BEGAIN;
> > > > ceph_mdsc_iterate_sessions(mdsc, send_flush_mdlog, true);
> > > > ceph_mdsc_iterate_sessions(mdsc, lock_unlock_session, false);
> > > > diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
> > > > index 81a1f9a4ac3b..56f9d8077068 100644
> > > > --- a/fs/ceph/mds_client.h
> > > > +++ b/fs/ceph/mds_client.h
> > > > @@ -398,6 +398,11 @@ struct cap_wait {
> > > > int want;
> > > > };
> > > > +enum {
> > > > + CEPH_MDSC_STOPPING_BEGAIN = 1,
> > > > + CEPH_MDSC_STOPPING_FLUSHED = 2,
> > > > +};
> > > > +
> > > > /*
> > > > * mds client state
> > > > */
> > > > @@ -414,7 +419,7 @@ struct ceph_mds_client {
> > > > struct ceph_mds_session **sessions; /* NULL for mds if no session */
> > > > atomic_t num_sessions;
> > > > int max_sessions; /* len of sessions array */
> > > > - int stopping; /* true if shutting down */
> > > > + int stopping; /* the stage of shutting down */
> > > > atomic64_t quotarealms_count; /* # realms with quota */
> > > > /*
> > > > diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
> > > > index 64592adfe48f..f5819fc31d28 100644
> > > > --- a/fs/ceph/quota.c
> > > > +++ b/fs/ceph/quota.c
> > > > @@ -47,6 +47,9 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
> > > > struct inode *inode;
> > > > struct ceph_inode_info *ci;
> > > > + if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED)
> > > > + return;
> > > > +
> > > > if (msg->front.iov_len < sizeof(*h)) {
> > > > pr_err("%s corrupt message mds%d len %d\n", __func__,
> > > > session->s_mds, (int)msg->front.iov_len);
> > > > diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
> > > > index a73943e51a77..eeabdd0211d8 100644
> > > > --- a/fs/ceph/snap.c
> > > > +++ b/fs/ceph/snap.c
> > > > @@ -1010,6 +1010,9 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc,
> > > > int locked_rwsem = 0;
> > > > bool close_sessions = false;
> > > > + if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED)
> > > > + return;
> > > > +
> > > > /* decode */
> > > > if (msg->front.iov_len < sizeof(*h))
> > > > goto bad;
> > > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> > > > index f10a076f47e5..012b35be41a9 100644
> > > > --- a/fs/ceph/super.c
> > > > +++ b/fs/ceph/super.c
> > > > @@ -1483,6 +1483,20 @@ static void ceph_kill_sb(struct super_block *s)
> > > > ceph_mdsc_pre_umount(fsc->mdsc);
> > > > flush_fs_workqueues(fsc);
> > > > + /*
> > > > + * Though the kill_anon_super() will finally trigger the
> > > > + * sync_filesystem() anyway, we still need to do it here and
> > > > + * then bump the stage of shutdown. This will drop any further
> > > > + * message, which makes no sense any more, from MDSs.
> > > > + *
> > > > + * Without this when evicting the inodes it may fail in the
> > > > + * kill_anon_super(), which will trigger a warning when
> > > > + * destroying the fscrypt keyring and then possibly trigger
> > > > + * a further crash in ceph module when iput() the inodes.
> > > > + */
> > > > + sync_filesystem(s);
> > > > + fsc->mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHED;
> > > > +
> > > > kill_anon_super(s);
> > > > fsc->client->extra_mon_dispatch = NULL;
> > > > --
> > > > 2.31.1
> > > >
> --
> Best Regards,
>
> Xiubo Li (李秀波)
>
> Email: xiubli@xxxxxxxxxx/xiubli@xxxxxxx
> Slack: @Xiubo Li
>
