On 23/01/2023 18:15, Luís Henriques wrote:
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.
Hi Luis,
I added some logs and found that when doing the aio_write, it will split
to many aio requests and when the last req finished it will call the
"writepages_finish()", which will iput() the inode and release the last
refcount of the inode.
But it seems the complete_all() is called without the req->r_callback()
is totally finished:
<4>[500400.268200] writepages_finish 0000000060940222 rc 0
<4>[500400.268476] writepages_finish 0000000060940222 rc 0 <===== the
last osd req->r_callback()
<4>[500400.268515] sync_fs (blocking) <===== unmounting begin
<4>[500400.268526] sync_fs (blocking) done
<4>[500400.268530] kill_sb after sync_filesystem 00000000a01a1cf4 <===
the sync_filesystem() will be called, I just added it in ceph code but
the VFS will call it again in "kill_anon_super()"
<4>[500400.268539] ceph_evict_inode:682, dec inode 0000000044f12aa7
<4>[500400.268626] sync_fs (blocking)
<4>[500400.268631] sync_fs (blocking) done
<4>[500400.268634] evict_inodes inode 0000000060940222, i_count = 1, was
skipped! <=== skipped
<4>[500400.268642] fscrypt_destroy_keyring: mk 00000000baf04977
mk_active_refs = 2
<4>[500400.268651] ceph_evict_inode:682, dec inode 0000000060940222
<==== evict the inode in the req->r_callback()
Locally my VM is not working and I couldn't run the test for now. Could
you help test the following patch ?
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 78b622178a3d..5cdaba0d3003 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -2539,6 +2539,7 @@ static void __complete_request(struct
ceph_osd_request *req)
if (req->r_callback)
req->r_callback(req);
+ barrier();
complete_all(&req->r_completion);
ceph_osdc_put_request(req);
}
Thanks
- Xiubo
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
--
Best Regards,
Xiubo Li (李秀波)
Email: xiubli@xxxxxxxxxx/xiubli@xxxxxxx
Slack: @Xiubo Li
