RE: [PATCH] Revert "ceph: when filling trace, call ceph_get_inode outside of mutexes"

Viacheslav Dubeyko
2026-04-24T18:12:11Z

On Thu, 2026-04-23 at 19:50 +0000, Viacheslav Dubeyko wrote:
> On Sat, 2026-04-18 at 12:12 +0800, Li Lei wrote:
> > This reverts commit bca9fc14c70fcbbebc84954cc39994e463fb9468.
> >
> > Deadlock detected between mdsc->snap_rwsem and the I_NEW bit in
> > handle_reply().
> >
> > - kworker/u113:1 (stat inode)
> > 1) Hold a inode with I_NEW set
> > 2) Request for mdsc->snap_rwsem
> > - kworker/u113:2 (readdir)
> > 1) Hold mdsc->snap_rwsem
> > 2) Wait for inode I_NEW flag to be cleared
> >
> > task:kworker/u113:1 state:D stack: 0 pid:34454 ppid: 2
> > flags:0x00004000
> > Workqueue: ceph-msgr ceph_con_workfn [libceph]
> > Call Trace:
> > __schedule+0x3a9/0x8d0
> > schedule+0x49/0xb0
> > rwsem_down_write_slowpath+0x30a/0x5e0
> > handle_reply+0x4d7/0x7f0 [ceph]
> > ? ceph_tcp_recvmsg+0x6f/0xa0 [libceph]
> > mds_dispatch+0x10a/0x690 [ceph]
> > ? calc_signature+0xdf/0x110 [libceph]
> > ? ceph_x_check_message_signature+0x58/0xc0 [libceph]
> > ceph_con_process_message+0x73/0x140 [libceph]
> > ceph_con_v1_try_read+0x2f2/0x860 [libceph]
> > ceph_con_workfn+0x31e/0x660 [libceph]
> > process_one_work+0x1cb/0x370
> > worker_thread+0x30/0x390
> > ? process_one_work+0x370/0x370
> > kthread+0x13e/0x160
> > ? set_kthread_struct+0x50/0x50
> > ret_from_fork+0x1f/0x30
> >
> > task:kworker/u113:2 state:D stack: 0 pid:54267 ppid: 2
> > flags:0x00004000
> > Workqueue: ceph-msgr ceph_con_workfn [libceph]
> > Call Trace:
> > __schedule+0x3a9/0x8d0
> > ? bit_wait_io+0x60/0x60
> > ? bit_wait_io+0x60/0x60
> > schedule+0x49/0xb0
> > bit_wait+0xd/0x60
> > __wait_on_bit+0x2a/0x90
> > ? ceph_force_reconnect+0x90/0x90 [ceph]
> > out_of_line_wait_on_bit+0x91/0xb0
> > ? bitmap_empty+0x20/0x20
> > ilookup5.part.29+0x69/0x90
> > ? ceph_force_reconnect+0x90/0x90 [ceph]
> > ? ceph_ino_compare+0x30/0x30 [ceph]
> > iget5_locked+0x26/0x90
> > ceph_get_inode+0x45/0x130 [ceph]
> > ceph_readdir_prepopulate+0x59f/0xca0 [ceph]
> > handle_reply+0x78d/0x7f0 [ceph]
> > ? ceph_tcp_recvmsg+0x6f/0xa0 [libceph]
> > mds_dispatch+0x10a/0x690 [ceph]
> > ? calc_signature+0xdf/0x110 [libceph]
> > ? ceph_x_check_message_signature+0x58/0xc0 [libceph]
> > ceph_con_process_message+0x73/0x140 [libceph]
> > ceph_con_v1_try_read+0x2f2/0x860 [libceph]
> > ceph_con_workfn+0x31e/0x660 [libceph]
> > process_one_work+0x1cb/0x370
> > worker_thread+0x30/0x390
> > ? process_one_work+0x370/0x370
> > kthread+0x13e/0x160
> > ? set_kthread_struct+0x50/0x50
> > ret_from_fork+0x1f/0x30
> >
> > It's rather rear to be caught, but here's Fast Reproduce Steps
> > (multiple mds is needed):
> > 1. Try to find 2 different directories (DIR_a DIR_b) in a cephfs cluster
> > and make sure they have different auth mds nodes. In this way, a client
> > may have chances to run handle_reply on different CPU for our test
> > (see step 5 and step 6).
> > 2. In DIR_b, create a hard link of DIR_a/FILE_a, namely FILE_b.
> > DIR_a/FILE_a and DIR_b/FILE_b have the same ino (123456 e.g)
> > 3. Save ino in code below, make it sleep for stat command.
> > ```
> > static void handle_reply(struct ceph_mds_session
> > *session, struct ceph_msg *msg)
> > goto out_err;
> > }
> > req->r_target_inode = in;
> > + if (in->i_ino == 123456) {
> > + pr_err("inode %lu found, ready to wait 10 seconds.\n",
> > + in->i_ino);
> > + msleep(10000);
> > + }
> > ```
> > 4. Execute echo 3 > /proc/sys/vm/drop_caches
> > 5. In a shell, do `cd DIR_a;stat DIR_a/FILE_a`, we suppose to be stuck on this shell
> > because of msleep() in handle_reply().
> > 6. In the other shell, do `cd DIR_b;ls DIR_b/` to trigger ceph_readdir_prepopulate()
> >
> > Repeat step 4-6, less than 10 times is enough to see the problem.
> >
> > It turns out that commit bca9fc14c70f ("ceph: when filling trace, call ceph_get_inode outside of mutexes")
> > moved ceph_inode_get outside snap_rmsem and made a chance for the deadlock of ceph_inode_get()
> > and snap_rwsem.
> >
> > After the following commit, original commit(bca9fc14c70f) can be reverted safely.
> > commit 6a92b08fdad2 ("ceph: don't take s_mutex or snap_rwsem in ceph_check_caps")
> >
> > Signed-off-by: Zhao Sun <sunzhao03@kuaishou.com>
> > Signed-off-by: Li Lei <lilei24@kuaishou.com>
> > ---
> > fs/ceph/inode.c | 26 ++++++++++++++++++++++----
> > fs/ceph/mds_client.c | 29 -----------------------------
> > 2 files changed, 22 insertions(+), 33 deletions(-)
> >
> > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> > index d99e12d..0c241a4 100644
> > --- a/fs/ceph/inode.c
> > +++ b/fs/ceph/inode.c
> > @@ -1667,10 +1667,28 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
> > }
> >
> > if (rinfo->head->is_target) {
> > - /* Should be filled in by handle_reply */
> > - BUG_ON(!req->r_target_inode);
> > + in = xchg(&req->r_new_inode, NULL);
> > + tvino.ino = le64_to_cpu(rinfo->targeti.in->ino);
> > + tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid);
> > +
> > + /*
> > + * If we ended up opening an existing inode, discard
> > + * r_new_inode
> > + */
> > + if (req->r_op == CEPH_MDS_OP_CREATE &&
> > + !req->r_reply_info.has_create_ino) {
> > + /* This should never happen on an async create */
> > + WARN_ON_ONCE(req->r_deleg_ino);
> > + iput(in);
> > + in = NULL;
> > + }
> > +
> > + in = ceph_get_inode(fsc->sb, tvino, in);
> > + if (IS_ERR(in)) {
> > + err = PTR_ERR(in);
> > + goto done;
> > + }
> >
> > - in = req->r_target_inode;
> > err = ceph_fill_inode(in, req->r_locked_page, &rinfo->targeti,
> > NULL, session,
> > (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags) &&
> > @@ -1680,13 +1698,13 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
> > if (err < 0) {
> > pr_err_client(cl, "badness %p %llx.%llx\n", in,
> > ceph_vinop(in));
> > - req->r_target_inode = NULL;
> > if (inode_state_read_once(in) & I_NEW)
> > discard_new_inode(in);
> > else
> > iput(in);
> > goto done;
> > }
> > + req->r_target_inode = in;
> > if (inode_state_read_once(in) & I_NEW)
> > unlock_new_inode(in);
> > }
> > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> > index b174627..8a27775 100644
> > --- a/fs/ceph/mds_client.c
> > +++ b/fs/ceph/mds_client.c
> > @@ -3941,36 +3941,7 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
> > session->s_con.peer_features);
> > mutex_unlock(&mdsc->mutex);
> >
> > - /* Must find target inode outside of mutexes to avoid deadlocks */
> > rinfo = &req->r_reply_info;
> > - if ((err >= 0) && rinfo->head->is_target) {
> > - struct inode *in = xchg(&req->r_new_inode, NULL);
> > - struct ceph_vino tvino = {
> > - .ino = le64_to_cpu(rinfo->targeti.in->ino),
> > - .snap = le64_to_cpu(rinfo->targeti.in->snapid)
> > - };
> > -
> > - /*
> > - * If we ended up opening an existing inode, discard
> > - * r_new_inode
> > - */
> > - if (req->r_op == CEPH_MDS_OP_CREATE &&
> > - !req->r_reply_info.has_create_ino) {
> > - /* This should never happen on an async create */
> > - WARN_ON_ONCE(req->r_deleg_ino);
> > - iput(in);
> > - in = NULL;
> > - }
> > -
> > - in = ceph_get_inode(mdsc->fsc->sb, tvino, in);
> > - if (IS_ERR(in)) {
> > - err = PTR_ERR(in);
> > - mutex_lock(&session->s_mutex);
> > - goto out_err;
> > - }
> > - req->r_target_inode = in;
> > - }
> > -
> > mutex_lock(&session->s_mutex);
> > if (err < 0) {
> > pr_err_client(cl, "got corrupt reply mds%d(tid:%lld)\n",
>
> Let me run xfstests for the patch to double check that nothing is broken.
>
>

Unexpectedly, I have a crash on generic/701 with your patch applied. I am going
to re-run xfstests without your patch.

generic/701 50s ... [failed, exit status 137]_check_dmesg: something found in
dmesg (see xfstests-dev/results//generic/701.dmesg)
- output mismatch (see xfstests-dev/results//generic/701.out.bad)
--- tests/generic/701.out 2026-04-01 19:47:53.878452478 -0700
+++ xfstests-dev/results//generic/701.out.bad 2026-04-24
04:57:37.887700953 -0700
@@ -1,2 +1,3 @@
QA output created by 701
-Number of allocated blocks after truncate is in range
+pwrite: Permission denied
+./check: line 700: 311685 Killed systemd-run --quiet --
unit "${unit}" --scope "${cmd[@]}"
...
(Run 'diff -u xfstests-dev/tests/generic/701.out xfstests-
dev/results//generic/701.out.bad' to see the entire diff)

Apr 23 22:42:26 ssdfs-vm-test kernel: [29717.030383] ceph: [2bf3efd7-3e1c-453d-
9665-3c75a0dc96dd 19499]: mds0 caps stale
Apr 23 22:43:18 ssdfs-vm-test kernel: [29733.938331] INFO: task
kworker/u32:0:241092 blocked for more than 122 seconds.
Apr 23 22:43:25 ssdfs-vm-test kernel: [29733.940727] Not tainted 7.0.0+ #9
Apr 23 22:43:25 ssdfs-vm-test kernel: [29733.941449] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
Apr 23 22:43:25 ssdfs-vm-test kernel: [29733.942756] task:kworker/u32:0
state:D stack:0 pid:241092 tgid:241092 ppid:2 task_flags:0x4208060
flags:0x00080000
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942773] Workqueue: writeback
wb_workfn (flush-ceph-766)
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942792] Call Trace:
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942795] <TASK>
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942803] __schedule+0x5b7/0x1fe0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942812] ? lock_acquire+0xc8/0x2f0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942819] ? schedule+0xb1/0x180
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942823] ? find_held_lock+0x31/0x90
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942829] ? schedule+0x10e/0x180
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942834] ? lock_release+0xd9/0x300
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942842] schedule+0x3a/0x180
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942847]
schedule_preempt_disabled+0x15/0x30
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942851] __mutex_lock+0x777/0x1220
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942858] ? ceph_con_send+0x4c/0x250
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942876]
mutex_lock_nested+0x1b/0x30
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.942881] ?
mutex_lock_nested+0x1b/0x30
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943136] ceph_con_send+0x4c/0x250
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943146] ? lock_acquire+0xc8/0x2f0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943158] send_request+0x7d0/0xcc0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943174] ?
do_raw_spin_unlock+0x4e/0xe0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943182] ?
_raw_spin_unlock+0x22/0x50
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943222]
__submit_request+0x2a9/0x4c0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943236]
ceph_osdc_start_request+0x6c/0x90
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943245]
ceph_writepages_start+0x101b/0x21e0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943254] ?
__lock_acquire+0x4a2/0x2650
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943331] do_writepages+0xc2/0x170
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943338] ? do_writepages+0xc2/0x170
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943342] ? lock_release+0xd9/0x300
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943347] ?
writeback_sb_inodes+0x1e7/0x900
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943358]
__writeback_single_inode+0x5a/0x5e0
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943365] ?
_raw_spin_unlock+0x22/0x50
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943377]
writeback_sb_inodes+0x29f/0x900
Apr 23 22:43:26 ssdfs-vm-test kernel: [29733.943435]
__writeback_inodes_wb+0x54/0xf0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943448] wb_writeback+0x3df/0x470
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943473] wb_workfn+0x364/0x520
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943493]
process_one_work+0x22f/0x620
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943515] worker_thread+0x1e2/0x400
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943525] ?
__pfx_worker_thread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943532] kthread+0x109/0x140
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943539] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943548] ret_from_fork+0x3e1/0x470
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943556] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943561] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943568]
ret_from_fork_asm+0x1a/0x30
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943595] </TASK>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.943669] INFO: task
kworker/u32:0:241092 is blocked on a mutex likely owned by task
kworker/7:4:308292.
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953769] task:kworker/7:4
state:R running task stack:0 pid:308292 tgid:308292 ppid:2
task_flags:0x4208860 flags:0x00080000
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953786] Workqueue: ceph-msgr
ceph_con_workfn
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953795] Call Trace:
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953798] <TASK>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953805] __schedule+0x5b7/0x1fe0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953809] ?
irqentry_exit+0x299/0x740
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953843] ?
sysvec_apic_timer_interrupt+0x54/0xd0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953858] preempt_schedule+0x4c/0x80
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953862]
preempt_schedule_thunk+0x16/0x30
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953874]
_raw_spin_unlock_irq+0x4f/0x70
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953880] evict_folios+0x394/0xf00
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953886] ?
hrtimer_start_range_ns+0x270/0x980
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953904] ?
lock_is_held_type+0xaa/0x140
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953916]
try_to_shrink_lruvec+0x1a9/0x3b0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953934] shrink_one+0xd1/0x1c0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953943] shrink_node+0xba8/0x13d0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953954] ? shrink_node+0xb7e/0x13d0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953969]
do_try_to_free_pages+0xc1/0x4f0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953974] ?
do_try_to_free_pages+0xc1/0x4f0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953984]
try_to_free_pages+0xe0/0x310
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.953989] ?
fs_reclaim_acquire+0x4f/0x100
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954009]
__alloc_frozen_pages_noprof+0xd49/0x1830
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954017] ?
ip_dst_mtu_maybe_forward.constprop.0+0x24/0x2a0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954034] ? lock_acquire+0xc8/0x2f0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954039] ?
__virt_addr_valid+0xf5/0x340
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954053] ?
policy_nodemask+0x122/0x1d0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954064]
alloc_pages_mpol+0xba/0x1a0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954069] ?
_copy_from_iter+0x273/0x790
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954080]
alloc_pages_noprof+0x59/0xe0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954087]
skb_page_frag_refill+0xc4/0xf0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954093]
sk_page_frag_refill+0x21/0xc0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954099]
tcp_sendmsg_locked+0x848/0x14e0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954122] tcp_sendmsg+0x30/0x60
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954128] inet_sendmsg+0x46/0x90
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954135] sock_sendmsg+0xf1/0x100
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954142] ? kfree+0x3ab/0x560
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954147] ?
__free_frozen_pages+0x6e0/0x730
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954157] ? sg_free_table+0x39/0x90
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954167] do_sendmsg+0x8d/0xe0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954197]
ceph_con_v2_try_write+0x99/0x560
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954206]
ceph_con_workfn+0x17f/0x820
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954215]
process_one_work+0x22f/0x620
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954221] ?
process_one_work+0x254/0x620
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954252] worker_thread+0x1e2/0x400
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954260] ?
__pfx_worker_thread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954265] kthread+0x109/0x140
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954271] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954278] ret_from_fork+0x3e1/0x470
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954283] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954287] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954293]
ret_from_fork_asm+0x1a/0x30
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954314] </TASK>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.954321] INFO: task
kworker/7:2:299107 blocked for more than 122 seconds.
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.955829] Not tainted 7.0.0+ #9
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.959909] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961590] task:kworker/7:2
state:D stack:0 pid:299107 tgid:299107 ppid:2 task_flags:0x4208060
flags:0x00080000
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961598] Workqueue: events
delayed_work
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961607] Call Trace:
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961610] <TASK>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961618] __schedule+0x5b7/0x1fe0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961622] ?
mark_held_locks+0x46/0x90
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961629] ? find_held_lock+0x31/0x90
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961634] ? schedule+0x10e/0x180
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961639] ? lock_release+0xd9/0x300
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961649] schedule+0x3a/0x180
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961653]
schedule_preempt_disabled+0x15/0x30
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961658]
rwsem_down_read_slowpath+0x27b/0x6c0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961662] ?
ceph_send_cap_releases+0x4b/0x370
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961672] ?
__queue_delayed_work+0x134/0x190
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961682] down_read+0x7c/0x190
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961687]
ceph_send_cap_releases+0x4b/0x370
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961692] ?
ceph_con_send+0x1e8/0x250
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961705] delayed_work+0x1d8/0x2b0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961715]
process_one_work+0x22f/0x620
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961730] worker_thread+0x1e2/0x400
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961738] ?
__pfx_worker_thread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961744] kthread+0x109/0x140
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961749] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961756] ret_from_fork+0x3e1/0x470
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961787] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961791] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961797]
ret_from_fork_asm+0x1a/0x30
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961818] </TASK>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.961851] INFO: task
kworker/7:2:299107 <reader> blocked on an rw-semaphore likely owned by task
kworker/u32:0:241092 <reader>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.972571] INFO: task
kworker/7:5:309930 blocked for more than 122 seconds.
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.973737] Not tainted 7.0.0+ #9
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.974413] "echo 0 >
/proc/sys/kernel/hung_task_timeout_secs" disables this message.
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978473] task:kworker/7:5
state:D stack:0 pid:309930 tgid:309930 ppid:2 task_flags:0x4208060
flags:0x00080000
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978479] Workqueue: events
handle_osds_timeout
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978485] Call Trace:
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978487] <TASK>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978493] __schedule+0x5b7/0x1fe0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978496] ?
mark_held_locks+0x46/0x90
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978502] ? find_held_lock+0x31/0x90
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978506] ? schedule+0x10e/0x180
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978509] ? lock_release+0xd9/0x300
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978537] schedule+0x3a/0x180
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978540]
schedule_preempt_disabled+0x15/0x30
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978543]
rwsem_down_write_slowpath+0x1f3/0x990
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978547] ? lock_acquire+0xc8/0x2f0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978556] ?
process_one_work+0x1ef/0x620
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978563] down_write+0xe4/0xf0
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978567]
handle_osds_timeout+0x45/0x160
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978573]
process_one_work+0x22f/0x620
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978585] worker_thread+0x1e2/0x400
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978591] ?
__pfx_worker_thread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978595] kthread+0x109/0x140
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978599] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978604] ret_from_fork+0x3e1/0x470
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978608] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978611] ? __pfx_kthread+0x10/0x10
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978615]
ret_from_fork_asm+0x1a/0x30
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978631] </TASK>
Apr 23 22:43:30 ssdfs-vm-test kernel: [29733.978653] INFO: task
kworker/7:5:309930 <writer> blocked on an rw-semaphore likely owned by task
kworker/u32:0:241092 <reader>

I am not completely sure that your patch is responsible.

Thanks,
Slava.