From: Xiubo Li <xiubli@xxxxxxxxxx> When unmounting and all the dirty buffer will be flushed and after the last osd request is finished the last reference of the i_count will be released. Then it will flush the dirty cap/snap to MDSs, and the unmounting won't wait the possible acks, which will ihode the inodes when updating the metadata locally but makes no sense any more, of this. This will make the evict_inodes() to skip these inodes. If encrypt is enabled the kernel generate a warning when removing the encrypt keys when the skipped inodes still hold the keyring: 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 Later the kernel will crash when iput() the inodes and dereferencing the "sb->s_master_keys", which has been released by the generic_shutdown_super(). URL: https://tracker.ceph.com/issues/58126 Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> --- fs/ceph/caps.c | 5 +++++ fs/ceph/mds_client.c | 12 +++++++++- fs/ceph/mds_client.h | 11 +++++++++- fs/ceph/quota.c | 4 ++++ fs/ceph/snap.c | 6 +++++ fs/ceph/super.c | 52 ++++++++++++++++++++++++++++++++++++++++++++ fs/ceph/super.h | 2 ++ 7 files changed, 90 insertions(+), 2 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 15d9e0f0d65a..ee38d2abeaed 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 (!ceph_inc_stopping_blocker(mdsc)) + return; + /* decode */ end = msg->front.iov_base + msg->front.iov_len; if (msg->front.iov_len < sizeof(*h)) @@ -4435,6 +4438,8 @@ void ceph_handle_caps(struct ceph_mds_session *session, done_unlocked: iput(inode); out: + ceph_dec_stopping_blocker(mdsc); + ceph_put_string(extra_info.pool_ns); /* Defer closing the sessions after s_mutex lock being released */ diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 1df2059a0333..71a8941c9cc5 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -4871,6 +4871,9 @@ static void handle_lease(struct ceph_mds_client *mdsc, dout("handle_lease from mds%d\n", mds); + if (!ceph_inc_stopping_blocker(mdsc)) + return; + /* decode */ if (msg->front.iov_len < sizeof(*h) + sizeof(u32)) goto bad; @@ -4952,9 +4955,13 @@ static void handle_lease(struct ceph_mds_client *mdsc, out: mutex_unlock(&session->s_mutex); iput(inode); + + ceph_dec_stopping_blocker(mdsc); return; bad: + ceph_dec_stopping_blocker(mdsc); + pr_err("corrupt lease message\n"); ceph_msg_dump(msg); } @@ -5150,6 +5157,9 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) } init_completion(&mdsc->safe_umount_waiters); + spin_lock_init(&mdsc->stopping_lock); + atomic_set(&mdsc->stopping_blockers, 0); + init_completion(&mdsc->stopping_waiter); init_waitqueue_head(&mdsc->session_close_wq); INIT_LIST_HEAD(&mdsc->waiting_for_map); mdsc->quotarealms_inodes = RB_ROOT; @@ -5264,7 +5274,7 @@ 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..5bf32701c84c 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 +419,11 @@ 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 */ + + spinlock_t stopping_lock; /* protect snap_empty */ + int stopping; /* the stage of shutting down */ + atomic_t stopping_blockers; + struct completion stopping_waiter; atomic64_t quotarealms_count; /* # realms with quota */ /* diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c index 64592adfe48f..3309ae071739 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 (!ceph_inc_stopping_blocker(mdsc)) + 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); @@ -78,6 +81,7 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc, spin_unlock(&ci->i_ceph_lock); iput(inode); + ceph_dec_stopping_blocker(mdsc); } static struct ceph_quotarealm_inode * diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 3d417ec8da0c..d4c6bd12e07d 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -1011,6 +1011,9 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc, int locked_rwsem = 0; bool close_sessions = false; + if (!ceph_inc_stopping_blocker(mdsc)) + return; + /* decode */ if (msg->front.iov_len < sizeof(*h)) goto bad; @@ -1134,12 +1137,15 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc, up_write(&mdsc->snap_rwsem); flush_snaps(mdsc); + ceph_dec_stopping_blocker(mdsc); return; bad: pr_err("%s corrupt snap message from mds%d\n", __func__, mds); ceph_msg_dump(msg); out: + ceph_dec_stopping_blocker(mdsc); + if (locked_rwsem) up_write(&mdsc->snap_rwsem); diff --git a/fs/ceph/super.c b/fs/ceph/super.c index f10a076f47e5..fa111c2a3732 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -1474,15 +1474,67 @@ static int ceph_init_fs_context(struct fs_context *fc) return -ENOMEM; } +/* + * Return true if mdsc successfully increase blocker counter, + * or false if the mdsc is in stopping and flushed state. + */ +bool ceph_inc_stopping_blocker(struct ceph_mds_client *mdsc) +{ + spin_lock(&mdsc->stopping_lock); + if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED) { + spin_unlock(&mdsc->stopping_lock); + return false; + } + atomic_inc(&mdsc->stopping_blockers); + spin_unlock(&mdsc->stopping_lock); + return true; +} + +void ceph_dec_stopping_blocker(struct ceph_mds_client *mdsc) +{ + spin_lock(&mdsc->stopping_lock); + if (!atomic_dec_return(&mdsc->stopping_blockers) && + mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED) + complete_all(&mdsc->stopping_waiter); + spin_unlock(&mdsc->stopping_lock); +} + static void ceph_kill_sb(struct super_block *s) { struct ceph_fs_client *fsc = ceph_sb_to_client(s); + bool wait; dout("kill_sb %p\n", 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 allow us to + * drop any further message, which will increase the inodes' + * i_count reference counters but 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 the iput() tries to + * evict the inodes later. + */ + sync_filesystem(s); + + spin_lock(&fsc->mdsc->stopping_lock); + fsc->mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHED; + wait = !!atomic_read(&fsc->mdsc->stopping_blockers); + spin_unlock(&fsc->mdsc->stopping_lock); + + while (wait || atomic_read(&fsc->mdsc->stopping_blockers)) { + wait = false; + wait_for_completion(&fsc->mdsc->stopping_waiter); + } + kill_anon_super(s); fsc->client->extra_mon_dispatch = NULL; diff --git a/fs/ceph/super.h b/fs/ceph/super.h index b2ef221474af..edd71b0a6bb4 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -1399,4 +1399,6 @@ extern bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf); extern void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc); +bool ceph_inc_stopping_blocker(struct ceph_mds_client *mdsc); +void ceph_dec_stopping_blocker(struct ceph_mds_client *mdsc); #endif /* _FS_CEPH_SUPER_H */ -- 2.31.1
