Re: [PATCH v2 07/10] cifsd: add oplock/lease cache mechanism

[J. Bruce Fields]

On Thu, Apr 22, 2021 at 09:28:21AM +0900, Namjae Jeon wrote:
> This adds oplock and lease cache mechanism.

Are leases and oplocks only enforced against other cifsd clients?  So, a
non-cifs user of the filesystem won't break cifsd's leases?

--b.

> 
> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
> Signed-off-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
> Acked-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
> ---
>  fs/cifsd/oplock.c | 1667 +++++++++++++++++++++++++++++++++++++++++++++
>  fs/cifsd/oplock.h |  133 ++++
>  2 files changed, 1800 insertions(+)
>  create mode 100644 fs/cifsd/oplock.c
>  create mode 100644 fs/cifsd/oplock.h
> 
> diff --git a/fs/cifsd/oplock.c b/fs/cifsd/oplock.c
> new file mode 100644
> index 000000000000..e77f1385a8c1
> --- /dev/null
> +++ b/fs/cifsd/oplock.c
> @@ -0,0 +1,1667 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + *   Copyright (C) 2016 Namjae Jeon <linkinjeon@xxxxxxxxxx>
> + *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
> + */
> +
> +#include <linux/moduleparam.h>
> +
> +#include "glob.h"
> +#include "oplock.h"
> +
> +#include "smb_common.h"
> +#include "smbstatus.h"
> +#include "buffer_pool.h"
> +#include "connection.h"
> +#include "mgmt/user_session.h"
> +#include "mgmt/share_config.h"
> +#include "mgmt/tree_connect.h"
> +
> +static LIST_HEAD(lease_table_list);
> +static DEFINE_RWLOCK(lease_list_lock);
> +
> +/**
> + * alloc_opinfo() - allocate a new opinfo object for oplock info
> + * @work:	smb work
> + * @id:		fid of open file
> + * @Tid:	tree id of connection
> + *
> + * Return:      allocated opinfo object on success, otherwise NULL
> + */
> +static struct oplock_info *alloc_opinfo(struct ksmbd_work *work,
> +		u64 id, __u16 Tid)
> +{
> +	struct ksmbd_session *sess = work->sess;
> +	struct oplock_info *opinfo;
> +
> +	opinfo = kzalloc(sizeof(struct oplock_info), GFP_KERNEL);
> +	if (!opinfo)
> +		return NULL;
> +
> +	opinfo->sess = sess;
> +	opinfo->conn = sess->conn;
> +	opinfo->level = OPLOCK_NONE;
> +	opinfo->op_state = OPLOCK_STATE_NONE;
> +	opinfo->pending_break = 0;
> +	opinfo->fid = id;
> +	opinfo->Tid = Tid;
> +	INIT_LIST_HEAD(&opinfo->op_entry);
> +	INIT_LIST_HEAD(&opinfo->interim_list);
> +	init_waitqueue_head(&opinfo->oplock_q);
> +	init_waitqueue_head(&opinfo->oplock_brk);
> +	atomic_set(&opinfo->refcount, 1);
> +	atomic_set(&opinfo->breaking_cnt, 0);
> +
> +	return opinfo;
> +}
> +
> +static void lease_add_list(struct oplock_info *opinfo)
> +{
> +	struct lease_table *lb = opinfo->o_lease->l_lb;
> +
> +	spin_lock(&lb->lb_lock);
> +	list_add_rcu(&opinfo->lease_entry, &lb->lease_list);
> +	spin_unlock(&lb->lb_lock);
> +}
> +
> +static void lease_del_list(struct oplock_info *opinfo)
> +{
> +	struct lease_table *lb = opinfo->o_lease->l_lb;
> +
> +	if (!lb)
> +		return;
> +
> +	spin_lock(&lb->lb_lock);
> +	if (list_empty(&opinfo->lease_entry)) {
> +		spin_unlock(&lb->lb_lock);
> +		return;
> +	}
> +
> +	list_del_init(&opinfo->lease_entry);
> +	opinfo->o_lease->l_lb = NULL;
> +	spin_unlock(&lb->lb_lock);
> +}
> +
> +static void lb_add(struct lease_table *lb)
> +{
> +	write_lock(&lease_list_lock);
> +	list_add(&lb->l_entry, &lease_table_list);
> +	write_unlock(&lease_list_lock);
> +}
> +
> +static int alloc_lease(struct oplock_info *opinfo, struct lease_ctx_info *lctx)
> +{
> +	struct lease *lease;
> +
> +	lease = kmalloc(sizeof(struct lease), GFP_KERNEL);
> +	if (!lease)
> +		return -ENOMEM;
> +
> +	memcpy(lease->lease_key, lctx->lease_key, SMB2_LEASE_KEY_SIZE);
> +	lease->state = lctx->req_state;
> +	lease->new_state = 0;
> +	lease->flags = lctx->flags;
> +	lease->duration = lctx->duration;
> +	INIT_LIST_HEAD(&opinfo->lease_entry);
> +	opinfo->o_lease = lease;
> +
> +	return 0;
> +}
> +
> +static void free_lease(struct oplock_info *opinfo)
> +{
> +	struct lease *lease;
> +
> +	lease = opinfo->o_lease;
> +	kfree(lease);
> +}
> +
> +static void free_opinfo(struct oplock_info *opinfo)
> +{
> +	if (opinfo->is_lease)
> +		free_lease(opinfo);
> +	kfree(opinfo);
> +}
> +
> +static inline void opinfo_free_rcu(struct rcu_head *rcu_head)
> +{
> +	struct oplock_info *opinfo;
> +
> +	opinfo = container_of(rcu_head, struct oplock_info, rcu_head);
> +	free_opinfo(opinfo);
> +}
> +
> +struct oplock_info *opinfo_get(struct ksmbd_file *fp)
> +{
> +	struct oplock_info *opinfo;
> +
> +	rcu_read_lock();
> +	opinfo = rcu_dereference(fp->f_opinfo);
> +	if (opinfo && !atomic_inc_not_zero(&opinfo->refcount))
> +		opinfo = NULL;
> +	rcu_read_unlock();
> +
> +	return opinfo;
> +}
> +
> +static struct oplock_info *opinfo_get_list(struct ksmbd_inode *ci)
> +{
> +	struct oplock_info *opinfo;
> +
> +	if (list_empty(&ci->m_op_list))
> +		return NULL;
> +
> +	rcu_read_lock();
> +	opinfo = list_first_or_null_rcu(&ci->m_op_list, struct oplock_info,
> +		op_entry);
> +	if (opinfo && !atomic_inc_not_zero(&opinfo->refcount))
> +		opinfo = NULL;
> +	rcu_read_unlock();
> +
> +	return opinfo;
> +}
> +
> +void opinfo_put(struct oplock_info *opinfo)
> +{
> +	if (!atomic_dec_and_test(&opinfo->refcount))
> +		return;
> +
> +	call_rcu(&opinfo->rcu_head, opinfo_free_rcu);
> +}
> +
> +static void opinfo_add(struct oplock_info *opinfo)
> +{
> +	struct ksmbd_inode *ci = opinfo->o_fp->f_ci;
> +
> +	write_lock(&ci->m_lock);
> +	list_add_rcu(&opinfo->op_entry, &ci->m_op_list);
> +	write_unlock(&ci->m_lock);
> +}
> +
> +static void opinfo_del(struct oplock_info *opinfo)
> +{
> +	struct ksmbd_inode *ci = opinfo->o_fp->f_ci;
> +
> +	if (opinfo->is_lease) {
> +		write_lock(&lease_list_lock);
> +		lease_del_list(opinfo);
> +		write_unlock(&lease_list_lock);
> +	}
> +	write_lock(&ci->m_lock);
> +	list_del_rcu(&opinfo->op_entry);
> +	write_unlock(&ci->m_lock);
> +}
> +
> +static unsigned long opinfo_count(struct ksmbd_file *fp)
> +{
> +	if (ksmbd_stream_fd(fp))
> +		return atomic_read(&fp->f_ci->sop_count);
> +	else
> +		return atomic_read(&fp->f_ci->op_count);
> +}
> +
> +static void opinfo_count_inc(struct ksmbd_file *fp)
> +{
> +	if (ksmbd_stream_fd(fp))
> +		return atomic_inc(&fp->f_ci->sop_count);
> +	else
> +		return atomic_inc(&fp->f_ci->op_count);
> +}
> +
> +static void opinfo_count_dec(struct ksmbd_file *fp)
> +{
> +	if (ksmbd_stream_fd(fp))
> +		return atomic_dec(&fp->f_ci->sop_count);
> +	else
> +		return atomic_dec(&fp->f_ci->op_count);
> +}
> +
> +/**
> + * opinfo_write_to_read() - convert a write oplock to read oplock
> + * @opinfo:		current oplock info
> + *
> + * Return:      0 on success, otherwise -EINVAL
> + */
> +int opinfo_write_to_read(struct oplock_info *opinfo)
> +{
> +	struct lease *lease = opinfo->o_lease;
> +
> +	if (!(opinfo->level == SMB2_OPLOCK_LEVEL_BATCH ||
> +	      opinfo->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE)) {
> +		ksmbd_err("bad oplock(0x%x)\n", opinfo->level);
> +		if (opinfo->is_lease)
> +			ksmbd_err("lease state(0x%x)\n", lease->state);
> +		return -EINVAL;
> +	}
> +	opinfo->level = SMB2_OPLOCK_LEVEL_II;
> +
> +	if (opinfo->is_lease)
> +		lease->state = lease->new_state;
> +	return 0;
> +}
> +
> +/**
> + * opinfo_read_handle_to_read() - convert a read/handle oplock to read oplock
> + * @opinfo:		current oplock info
> + *
> + * Return:      0 on success, otherwise -EINVAL
> + */
> +int opinfo_read_handle_to_read(struct oplock_info *opinfo)
> +{
> +	struct lease *lease = opinfo->o_lease;
> +
> +	lease->state = lease->new_state;
> +	opinfo->level = SMB2_OPLOCK_LEVEL_II;
> +	return 0;
> +}
> +
> +/**
> + * opinfo_write_to_none() - convert a write oplock to none
> + * @opinfo:	current oplock info
> + *
> + * Return:      0 on success, otherwise -EINVAL
> + */
> +int opinfo_write_to_none(struct oplock_info *opinfo)
> +{
> +	struct lease *lease = opinfo->o_lease;
> +
> +	if (!(opinfo->level == SMB2_OPLOCK_LEVEL_BATCH ||
> +	      opinfo->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE)) {
> +		ksmbd_err("bad oplock(0x%x)\n", opinfo->level);
> +		if (opinfo->is_lease)
> +			ksmbd_err("lease state(0x%x)\n",
> +					lease->state);
> +		return -EINVAL;
> +	}
> +	opinfo->level = SMB2_OPLOCK_LEVEL_NONE;
> +	if (opinfo->is_lease)
> +		lease->state = lease->new_state;
> +	return 0;
> +}
> +
> +/**
> + * opinfo_read_to_none() - convert a write read to none
> + * @opinfo:	current oplock info
> + *
> + * Return:      0 on success, otherwise -EINVAL
> + */
> +int opinfo_read_to_none(struct oplock_info *opinfo)
> +{
> +	struct lease *lease = opinfo->o_lease;
> +
> +	if (opinfo->level != SMB2_OPLOCK_LEVEL_II) {
> +		ksmbd_err("bad oplock(0x%x)\n", opinfo->level);
> +		if (opinfo->is_lease)
> +			ksmbd_err("lease state(0x%x)\n", lease->state);
> +		return -EINVAL;
> +	}
> +	opinfo->level = SMB2_OPLOCK_LEVEL_NONE;
> +	if (opinfo->is_lease)
> +		lease->state = lease->new_state;
> +	return 0;
> +}
> +
> +/**
> + * lease_read_to_write() - upgrade lease state from read to write
> + * @opinfo:	current lease info
> + *
> + * Return:      0 on success, otherwise -EINVAL
> + */
> +int lease_read_to_write(struct oplock_info *opinfo)
> +{
> +	struct lease *lease = opinfo->o_lease;
> +
> +	if (!(lease->state & SMB2_LEASE_READ_CACHING_LE)) {
> +		ksmbd_debug(OPLOCK, "bad lease state(0x%x)\n",
> +				lease->state);
> +		return -EINVAL;
> +	}
> +
> +	lease->new_state = SMB2_LEASE_NONE_LE;
> +	lease->state |= SMB2_LEASE_WRITE_CACHING_LE;
> +	if (lease->state & SMB2_LEASE_HANDLE_CACHING_LE)
> +		opinfo->level = SMB2_OPLOCK_LEVEL_BATCH;
> +	else
> +		opinfo->level = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
> +	return 0;
> +}
> +
> +/**
> + * lease_none_upgrade() - upgrade lease state from none
> + * @opinfo:	current lease info
> + * @new_state:	new lease state
> + *
> + * Return:	0 on success, otherwise -EINVAL
> + */
> +static int lease_none_upgrade(struct oplock_info *opinfo, __le32 new_state)
> +{
> +	struct lease *lease = opinfo->o_lease;
> +
> +	if (!(lease->state == SMB2_LEASE_NONE_LE)) {
> +		ksmbd_debug(OPLOCK, "bad lease state(0x%x)\n",
> +				lease->state);
> +		return -EINVAL;
> +	}
> +
> +	lease->new_state = SMB2_LEASE_NONE_LE;
> +	lease->state = new_state;
> +	if (lease->state & SMB2_LEASE_HANDLE_CACHING_LE)
> +		if (lease->state & SMB2_LEASE_WRITE_CACHING_LE)
> +			opinfo->level = SMB2_OPLOCK_LEVEL_BATCH;
> +		else
> +			opinfo->level = SMB2_OPLOCK_LEVEL_II;
> +	else if (lease->state & SMB2_LEASE_WRITE_CACHING_LE)
> +		opinfo->level = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
> +	else if (lease->state & SMB2_LEASE_READ_CACHING_LE)
> +		opinfo->level = SMB2_OPLOCK_LEVEL_II;
> +
> +	return 0;
> +}
> +
> +/**
> + * close_id_del_oplock() - release oplock object at file close time
> + * @fp:		ksmbd file pointer
> + */
> +void close_id_del_oplock(struct ksmbd_file *fp)
> +{
> +	struct oplock_info *opinfo;
> +
> +	if (S_ISDIR(file_inode(fp->filp)->i_mode))
> +		return;
> +
> +	opinfo = opinfo_get(fp);
> +	if (!opinfo)
> +		return;
> +
> +	opinfo_del(opinfo);
> +
> +	rcu_assign_pointer(fp->f_opinfo, NULL);
> +	if (opinfo->op_state == OPLOCK_ACK_WAIT) {
> +		opinfo->op_state = OPLOCK_CLOSING;
> +		wake_up_interruptible_all(&opinfo->oplock_q);
> +		if (opinfo->is_lease) {
> +			atomic_set(&opinfo->breaking_cnt, 0);
> +			wake_up_interruptible_all(&opinfo->oplock_brk);
> +		}
> +	}
> +
> +	opinfo_count_dec(fp);
> +	atomic_dec(&opinfo->refcount);
> +	opinfo_put(opinfo);
> +}
> +
> +/**
> + * grant_write_oplock() - grant exclusive/batch oplock or write lease
> + * @opinfo_new:	new oplock info object
> + * @req_oplock: request oplock
> + * @lctx:	lease context information
> + *
> + * Return:      0
> + */
> +static void grant_write_oplock(struct oplock_info *opinfo_new, int req_oplock,
> +		struct lease_ctx_info *lctx)
> +{
> +	struct lease *lease = opinfo_new->o_lease;
> +
> +	if (req_oplock == SMB2_OPLOCK_LEVEL_BATCH)
> +		opinfo_new->level = SMB2_OPLOCK_LEVEL_BATCH;
> +	else
> +		opinfo_new->level = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
> +
> +	if (lctx) {
> +		lease->state = lctx->req_state;
> +		memcpy(lease->lease_key, lctx->lease_key,
> +				SMB2_LEASE_KEY_SIZE);
> +	}
> +}
> +
> +/**
> + * grant_read_oplock() - grant level2 oplock or read lease
> + * @opinfo_new:	new oplock info object
> + * @lctx:	lease context information
> + *
> + * Return:      0
> + */
> +static void grant_read_oplock(struct oplock_info *opinfo_new,
> +		struct lease_ctx_info *lctx)
> +{
> +	struct lease *lease = opinfo_new->o_lease;
> +
> +	opinfo_new->level = SMB2_OPLOCK_LEVEL_II;
> +
> +	if (lctx) {
> +		lease->state = SMB2_LEASE_READ_CACHING_LE;
> +		if (lctx->req_state & SMB2_LEASE_HANDLE_CACHING_LE)
> +			lease->state |= SMB2_LEASE_HANDLE_CACHING_LE;
> +		memcpy(lease->lease_key, lctx->lease_key,
> +				SMB2_LEASE_KEY_SIZE);
> +	}
> +}
> +
> +/**
> + * grant_none_oplock() - grant none oplock or none lease
> + * @opinfo_new:	new oplock info object
> + * @lctx:	lease context information
> + *
> + * Return:      0
> + */
> +static void grant_none_oplock(struct oplock_info *opinfo_new,
> +		struct lease_ctx_info *lctx)
> +{
> +	struct lease *lease = opinfo_new->o_lease;
> +
> +	opinfo_new->level = SMB2_OPLOCK_LEVEL_NONE;
> +
> +	if (lctx) {
> +		lease->state = 0;
> +		memcpy(lease->lease_key, lctx->lease_key,
> +			SMB2_LEASE_KEY_SIZE);
> +	}
> +}
> +
> +static inline int compare_guid_key(struct oplock_info *opinfo,
> +		const char *guid1, const char *key1)
> +{
> +	const char *guid2, *key2;
> +
> +	guid2 = opinfo->conn->ClientGUID;
> +	key2 = opinfo->o_lease->lease_key;
> +	if (!memcmp(guid1, guid2, SMB2_CLIENT_GUID_SIZE) &&
> +	    !memcmp(key1, key2, SMB2_LEASE_KEY_SIZE))
> +		return 1;
> +
> +	return 0;
> +}
> +
> +/**
> + * same_client_has_lease() - check whether current lease request is
> + *		from lease owner of file
> + * @ci:		master file pointer
> + * @client_guid:	Client GUID
> + * @lctx:		lease context information
> + *
> + * Return:      oplock(lease) object on success, otherwise NULL
> + */
> +static struct oplock_info *same_client_has_lease(struct ksmbd_inode *ci,
> +		char *client_guid, struct lease_ctx_info *lctx)
> +{
> +	int ret;
> +	struct lease *lease;
> +	struct oplock_info *opinfo;
> +	struct oplock_info *m_opinfo = NULL;
> +
> +	if (!lctx)
> +		return NULL;
> +
> +	/*
> +	 * Compare lease key and client_guid to know request from same owner
> +	 * of same client
> +	 */
> +	read_lock(&ci->m_lock);
> +	list_for_each_entry(opinfo, &ci->m_op_list, op_entry) {
> +		if (!opinfo->is_lease)
> +			continue;
> +		read_unlock(&ci->m_lock);
> +		lease = opinfo->o_lease;
> +
> +		ret = compare_guid_key(opinfo, client_guid, lctx->lease_key);
> +		if (ret) {
> +			m_opinfo = opinfo;
> +			/* skip upgrading lease about breaking lease */
> +			if (atomic_read(&opinfo->breaking_cnt)) {
> +				read_lock(&ci->m_lock);
> +				continue;
> +			}
> +
> +			/* upgrading lease */
> +			if ((atomic_read(&ci->op_count) +
> +			     atomic_read(&ci->sop_count)) == 1) {
> +				if (lease->state ==
> +					(lctx->req_state & lease->state)) {
> +					lease->state |= lctx->req_state;
> +					if (lctx->req_state &
> +						SMB2_LEASE_WRITE_CACHING_LE)
> +						lease_read_to_write(opinfo);
> +				}
> +			} else if ((atomic_read(&ci->op_count) +
> +				    atomic_read(&ci->sop_count)) > 1) {
> +				if (lctx->req_state ==
> +					(SMB2_LEASE_READ_CACHING_LE |
> +					 SMB2_LEASE_HANDLE_CACHING_LE))
> +					lease->state = lctx->req_state;
> +			}
> +
> +			if (lctx->req_state && lease->state ==
> +					SMB2_LEASE_NONE_LE)
> +				lease_none_upgrade(opinfo, lctx->req_state);
> +		}
> +		read_lock(&ci->m_lock);
> +	}
> +	read_unlock(&ci->m_lock);
> +
> +	return m_opinfo;
> +}
> +
> +static void wait_for_break_ack(struct oplock_info *opinfo)
> +{
> +	int rc = 0;
> +
> +	rc = wait_event_interruptible_timeout(opinfo->oplock_q,
> +		opinfo->op_state == OPLOCK_STATE_NONE ||
> +		opinfo->op_state == OPLOCK_CLOSING,
> +		OPLOCK_WAIT_TIME);
> +
> +	/* is this a timeout ? */
> +	if (!rc) {
> +		if (opinfo->is_lease)
> +			opinfo->o_lease->state = SMB2_LEASE_NONE_LE;
> +		opinfo->level = SMB2_OPLOCK_LEVEL_NONE;
> +		opinfo->op_state = OPLOCK_STATE_NONE;
> +	}
> +}
> +
> +static void wake_up_oplock_break(struct oplock_info *opinfo)
> +{
> +	clear_bit_unlock(0, &opinfo->pending_break);
> +	/* memory barrier is needed for wake_up_bit() */
> +	smp_mb__after_atomic();
> +	wake_up_bit(&opinfo->pending_break, 0);
> +}
> +
> +static int oplock_break_pending(struct oplock_info *opinfo, int req_op_level)
> +{
> +	while (test_and_set_bit(0, &opinfo->pending_break)) {
> +		wait_on_bit(&opinfo->pending_break, 0, TASK_UNINTERRUPTIBLE);
> +
> +		/* Not immediately break to none. */
> +		opinfo->open_trunc = 0;
> +
> +		if (opinfo->op_state == OPLOCK_CLOSING)
> +			return -ENOENT;
> +		else if (!opinfo->is_lease && opinfo->level <= req_op_level)
> +			return 1;
> +	}
> +
> +	if (!opinfo->is_lease && opinfo->level <= req_op_level) {
> +		wake_up_oplock_break(opinfo);
> +		return 1;
> +	}
> +	return 0;
> +}
> +
> +static inline int allocate_oplock_break_buf(struct ksmbd_work *work)
> +{
> +	work->response_buf = kzalloc(MAX_CIFS_SMALL_BUFFER_SIZE, GFP_KERNEL);
> +	if (!work->response_buf)
> +		return -ENOMEM;
> +	work->response_sz = MAX_CIFS_SMALL_BUFFER_SIZE;
> +	return 0;
> +}
> +
> +/**
> + * __smb2_oplock_break_noti() - send smb2 oplock break cmd from conn
> + * to client
> + * @wk:     smb work object
> + *
> + * There are two ways this function can be called. 1- while file open we break
> + * from exclusive/batch lock to levelII oplock and 2- while file write/truncate
> + * we break from levelII oplock no oplock.
> + * work->request_buf contains oplock_info.
> + */
> +static void __smb2_oplock_break_noti(struct work_struct *wk)
> +{
> +	struct smb2_oplock_break *rsp = NULL;
> +	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
> +	struct ksmbd_conn *conn = work->conn;
> +	struct oplock_break_info *br_info = work->request_buf;
> +	struct smb2_hdr *rsp_hdr;
> +	struct ksmbd_file *fp;
> +
> +	fp = ksmbd_lookup_durable_fd(br_info->fid);
> +	if (!fp) {
> +		atomic_dec(&conn->r_count);
> +		ksmbd_free_work_struct(work);
> +		return;
> +	}
> +
> +	if (allocate_oplock_break_buf(work)) {
> +		ksmbd_err("smb2_allocate_rsp_buf failed! ");
> +		atomic_dec(&conn->r_count);
> +		ksmbd_fd_put(work, fp);
> +		ksmbd_free_work_struct(work);
> +		return;
> +	}
> +
> +	rsp_hdr = work->response_buf;
> +	memset(rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);
> +	rsp_hdr->smb2_buf_length = cpu_to_be32(HEADER_SIZE_NO_BUF_LEN(conn));
> +	rsp_hdr->ProtocolId = SMB2_PROTO_NUMBER;
> +	rsp_hdr->StructureSize = SMB2_HEADER_STRUCTURE_SIZE;
> +	rsp_hdr->CreditRequest = cpu_to_le16(0);
> +	rsp_hdr->Command = SMB2_OPLOCK_BREAK;
> +	rsp_hdr->Flags = (SMB2_FLAGS_SERVER_TO_REDIR);
> +	rsp_hdr->NextCommand = 0;
> +	rsp_hdr->MessageId = cpu_to_le64(-1);
> +	rsp_hdr->Id.SyncId.ProcessId = 0;
> +	rsp_hdr->Id.SyncId.TreeId = 0;
> +	rsp_hdr->SessionId = 0;
> +	memset(rsp_hdr->Signature, 0, 16);
> +
> +	rsp = work->response_buf;
> +
> +	rsp->StructureSize = cpu_to_le16(24);
> +	if (!br_info->open_trunc &&
> +	    (br_info->level == SMB2_OPLOCK_LEVEL_BATCH ||
> +	     br_info->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE))
> +		rsp->OplockLevel = SMB2_OPLOCK_LEVEL_II;
> +	else
> +		rsp->OplockLevel = SMB2_OPLOCK_LEVEL_NONE;
> +	rsp->Reserved = 0;
> +	rsp->Reserved2 = 0;
> +	rsp->PersistentFid = cpu_to_le64(fp->persistent_id);
> +	rsp->VolatileFid = cpu_to_le64(fp->volatile_id);
> +
> +	inc_rfc1001_len(rsp, 24);
> +
> +	ksmbd_debug(OPLOCK,
> +		"sending oplock break v_id %llu p_id = %llu lock level = %d\n",
> +		rsp->VolatileFid, rsp->PersistentFid, rsp->OplockLevel);
> +
> +	ksmbd_fd_put(work, fp);
> +	ksmbd_conn_write(work);
> +	ksmbd_free_work_struct(work);
> +	atomic_dec(&conn->r_count);
> +}
> +
> +/**
> + * smb2_oplock_break_noti() - send smb2 exclusive/batch to level2 oplock
> + *		break command from server to client
> + * @opinfo:		oplock info object
> + *
> + * Return:      0 on success, otherwise error
> + */
> +static int smb2_oplock_break_noti(struct oplock_info *opinfo)
> +{
> +	struct ksmbd_conn *conn = opinfo->conn;
> +	struct oplock_break_info *br_info;
> +	int ret = 0;
> +	struct ksmbd_work *work = ksmbd_alloc_work_struct();
> +
> +	if (!work)
> +		return -ENOMEM;
> +
> +	br_info = kmalloc(sizeof(struct oplock_break_info), GFP_KERNEL);
> +	if (!br_info) {
> +		ksmbd_free_work_struct(work);
> +		return -ENOMEM;
> +	}
> +
> +	br_info->level = opinfo->level;
> +	br_info->fid = opinfo->fid;
> +	br_info->open_trunc = opinfo->open_trunc;
> +
> +	work->request_buf = (char *)br_info;
> +	work->conn = conn;
> +	work->sess = opinfo->sess;
> +
> +	atomic_inc(&conn->r_count);
> +	if (opinfo->op_state == OPLOCK_ACK_WAIT) {
> +		INIT_WORK(&work->work, __smb2_oplock_break_noti);
> +		ksmbd_queue_work(work);
> +
> +		wait_for_break_ack(opinfo);
> +	} else {
> +		__smb2_oplock_break_noti(&work->work);
> +		if (opinfo->level == SMB2_OPLOCK_LEVEL_II)
> +			opinfo->level = SMB2_OPLOCK_LEVEL_NONE;
> +	}
> +	return ret;
> +}
> +
> +/**
> + * __smb2_lease_break_noti() - send lease break command from server
> + * to client
> + * @wk:     smb work object
> + */
> +static void __smb2_lease_break_noti(struct work_struct *wk)
> +{
> +	struct smb2_lease_break *rsp = NULL;
> +	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
> +	struct lease_break_info *br_info = work->request_buf;
> +	struct ksmbd_conn *conn = work->conn;
> +	struct smb2_hdr *rsp_hdr;
> +
> +	if (allocate_oplock_break_buf(work)) {
> +		ksmbd_debug(OPLOCK, "smb2_allocate_rsp_buf failed! ");
> +		ksmbd_free_work_struct(work);
> +		atomic_dec(&conn->r_count);
> +		return;
> +	}
> +
> +	rsp_hdr = work->response_buf;
> +	memset(rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);
> +	rsp_hdr->smb2_buf_length = cpu_to_be32(HEADER_SIZE_NO_BUF_LEN(conn));
> +	rsp_hdr->ProtocolId = SMB2_PROTO_NUMBER;
> +	rsp_hdr->StructureSize = SMB2_HEADER_STRUCTURE_SIZE;
> +	rsp_hdr->CreditRequest = cpu_to_le16(0);
> +	rsp_hdr->Command = SMB2_OPLOCK_BREAK;
> +	rsp_hdr->Flags = (SMB2_FLAGS_SERVER_TO_REDIR);
> +	rsp_hdr->NextCommand = 0;
> +	rsp_hdr->MessageId = cpu_to_le64(-1);
> +	rsp_hdr->Id.SyncId.ProcessId = 0;
> +	rsp_hdr->Id.SyncId.TreeId = 0;
> +	rsp_hdr->SessionId = 0;
> +	memset(rsp_hdr->Signature, 0, 16);
> +
> +	rsp = work->response_buf;
> +	rsp->StructureSize = cpu_to_le16(44);
> +	rsp->Reserved = 0;
> +	rsp->Flags = 0;
> +
> +	if (br_info->curr_state & (SMB2_LEASE_WRITE_CACHING_LE |
> +			SMB2_LEASE_HANDLE_CACHING_LE))
> +		rsp->Flags = SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED;
> +
> +	memcpy(rsp->LeaseKey, br_info->lease_key, SMB2_LEASE_KEY_SIZE);
> +	rsp->CurrentLeaseState = br_info->curr_state;
> +	rsp->NewLeaseState = br_info->new_state;
> +	rsp->BreakReason = 0;
> +	rsp->AccessMaskHint = 0;
> +	rsp->ShareMaskHint = 0;
> +
> +	inc_rfc1001_len(rsp, 44);
> +
> +	ksmbd_conn_write(work);
> +	ksmbd_free_work_struct(work);
> +	atomic_dec(&conn->r_count);
> +}
> +
> +/**
> + * smb2_lease_break_noti() - break lease when a new client request
> + *			write lease
> + * @opinfo:		conains lease state information
> + *
> + * Return:	0 on success, otherwise error
> + */
> +static int smb2_lease_break_noti(struct oplock_info *opinfo)
> +{
> +	struct ksmbd_conn *conn = opinfo->conn;
> +	struct list_head *tmp, *t;
> +	struct ksmbd_work *work;
> +	struct lease_break_info *br_info;
> +	struct lease *lease = opinfo->o_lease;
> +
> +	work = ksmbd_alloc_work_struct();
> +	if (!work)
> +		return -ENOMEM;
> +
> +	br_info = kmalloc(sizeof(struct lease_break_info), GFP_KERNEL);
> +	if (!br_info) {
> +		ksmbd_free_work_struct(work);
> +		return -ENOMEM;
> +	}
> +
> +	br_info->curr_state = lease->state;
> +	br_info->new_state = lease->new_state;
> +	memcpy(br_info->lease_key, lease->lease_key, SMB2_LEASE_KEY_SIZE);
> +
> +	work->request_buf = (char *)br_info;
> +	work->conn = conn;
> +	work->sess = opinfo->sess;
> +
> +	atomic_inc(&conn->r_count);
> +	if (opinfo->op_state == OPLOCK_ACK_WAIT) {
> +		list_for_each_safe(tmp, t, &opinfo->interim_list) {
> +			struct ksmbd_work *in_work;
> +
> +			in_work = list_entry(tmp, struct ksmbd_work,
> +				interim_entry);
> +			setup_async_work(in_work, NULL, NULL);
> +			smb2_send_interim_resp(in_work, STATUS_PENDING);
> +			list_del(&in_work->interim_entry);
> +		}
> +		INIT_WORK(&work->work, __smb2_lease_break_noti);
> +		ksmbd_queue_work(work);
> +		wait_for_break_ack(opinfo);
> +	} else {
> +		__smb2_lease_break_noti(&work->work);
> +		if (opinfo->o_lease->new_state == SMB2_LEASE_NONE_LE) {
> +			opinfo->level = SMB2_OPLOCK_LEVEL_NONE;
> +			opinfo->o_lease->state = SMB2_LEASE_NONE_LE;
> +		}
> +	}
> +	return 0;
> +}
> +
> +static void wait_lease_breaking(struct oplock_info *opinfo)
> +{
> +	if (!opinfo->is_lease)
> +		return;
> +
> +	wake_up_interruptible_all(&opinfo->oplock_brk);
> +	if (atomic_read(&opinfo->breaking_cnt)) {
> +		int ret = 0;
> +
> +		ret = wait_event_interruptible_timeout(opinfo->oplock_brk,
> +			atomic_read(&opinfo->breaking_cnt) == 0, HZ);
> +		if (!ret)
> +			atomic_set(&opinfo->breaking_cnt, 0);
> +	}
> +}
> +
> +static int oplock_break(struct oplock_info *brk_opinfo, int req_op_level)
> +{
> +	int err = 0;
> +
> +	/* Need to break exclusive/batch oplock, write lease or overwrite_if */
> +	ksmbd_debug(OPLOCK,
> +		"request to send oplock(level : 0x%x) break notification\n",
> +		brk_opinfo->level);
> +
> +	if (brk_opinfo->is_lease) {
> +		struct lease *lease = brk_opinfo->o_lease;
> +
> +		atomic_inc(&brk_opinfo->breaking_cnt);
> +
> +		err = oplock_break_pending(brk_opinfo, req_op_level);
> +		if (err)
> +			return err < 0 ? err : 0;
> +
> +		if (brk_opinfo->open_trunc) {
> +			/*
> +			 * Create overwrite break trigger the lease break to
> +			 * none.
> +			 */
> +			lease->new_state = SMB2_LEASE_NONE_LE;
> +		} else {
> +			if (lease->state & SMB2_LEASE_WRITE_CACHING_LE) {
> +				if (lease->state & SMB2_LEASE_HANDLE_CACHING_LE)
> +					lease->new_state =
> +						SMB2_LEASE_READ_CACHING_LE |
> +						SMB2_LEASE_HANDLE_CACHING_LE;
> +				else
> +					lease->new_state =
> +						SMB2_LEASE_READ_CACHING_LE;
> +			} else {
> +				if (lease->state & SMB2_LEASE_HANDLE_CACHING_LE)
> +					lease->new_state =
> +						SMB2_LEASE_READ_CACHING_LE;
> +				else
> +					lease->new_state = SMB2_LEASE_NONE_LE;
> +			}
> +		}
> +
> +		if (lease->state & (SMB2_LEASE_WRITE_CACHING_LE |
> +				SMB2_LEASE_HANDLE_CACHING_LE))
> +			brk_opinfo->op_state = OPLOCK_ACK_WAIT;
> +		else
> +			atomic_dec(&brk_opinfo->breaking_cnt);
> +	} else {
> +		err = oplock_break_pending(brk_opinfo, req_op_level);
> +		if (err)
> +			return err < 0 ? err : 0;
> +
> +		if (brk_opinfo->level == SMB2_OPLOCK_LEVEL_BATCH ||
> +		    brk_opinfo->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE)
> +			brk_opinfo->op_state = OPLOCK_ACK_WAIT;
> +	}
> +
> +	if (brk_opinfo->is_lease)
> +		err = smb2_lease_break_noti(brk_opinfo);
> +	else
> +		err = smb2_oplock_break_noti(brk_opinfo);
> +
> +	ksmbd_debug(OPLOCK, "oplock granted = %d\n", brk_opinfo->level);
> +	if (brk_opinfo->op_state == OPLOCK_CLOSING)
> +		err = -ENOENT;
> +	wake_up_oplock_break(brk_opinfo);
> +
> +	wait_lease_breaking(brk_opinfo);
> +
> +	return err;
> +}
> +
> +void destroy_lease_table(struct ksmbd_conn *conn)
> +{
> +	struct lease_table *lb, *lbtmp;
> +	struct oplock_info *opinfo;
> +
> +	write_lock(&lease_list_lock);
> +	if (list_empty(&lease_table_list)) {
> +		write_unlock(&lease_list_lock);
> +		return;
> +	}
> +
> +	list_for_each_entry_safe(lb, lbtmp, &lease_table_list, l_entry) {
> +		if (conn && memcmp(lb->client_guid, conn->ClientGUID,
> +				   SMB2_CLIENT_GUID_SIZE))
> +			continue;
> +again:
> +		rcu_read_lock();
> +		list_for_each_entry_rcu(opinfo, &lb->lease_list,
> +				lease_entry) {
> +			rcu_read_unlock();
> +			lease_del_list(opinfo);
> +			goto again;
> +		}
> +		rcu_read_unlock();
> +		list_del(&lb->l_entry);
> +		kfree(lb);
> +	}
> +	write_unlock(&lease_list_lock);
> +}
> +
> +int find_same_lease_key(struct ksmbd_session *sess, struct ksmbd_inode *ci,
> +		struct lease_ctx_info *lctx)
> +{
> +	struct oplock_info *opinfo;
> +	int err = 0;
> +	struct lease_table *lb;
> +
> +	if (!lctx)
> +		return err;
> +
> +	read_lock(&lease_list_lock);
> +	if (list_empty(&lease_table_list)) {
> +		read_unlock(&lease_list_lock);
> +		return 0;
> +	}
> +
> +	list_for_each_entry(lb, &lease_table_list, l_entry) {
> +		if (!memcmp(lb->client_guid, sess->conn->ClientGUID,
> +			    SMB2_CLIENT_GUID_SIZE))
> +			goto found;
> +	}
> +	read_unlock(&lease_list_lock);
> +
> +	return 0;
> +
> +found:
> +	rcu_read_lock();
> +	list_for_each_entry_rcu(opinfo, &lb->lease_list,
> +			lease_entry) {
> +		if (!atomic_inc_not_zero(&opinfo->refcount))
> +			continue;
> +		rcu_read_unlock();
> +		if (opinfo->o_fp->f_ci == ci)
> +			goto op_next;
> +		err = compare_guid_key(opinfo,
> +				sess->conn->ClientGUID,
> +				lctx->lease_key);
> +		if (err) {
> +			err = -EINVAL;
> +			ksmbd_debug(OPLOCK,
> +				"found same lease key is already used in other files\n");
> +			opinfo_put(opinfo);
> +			goto out;
> +		}
> +op_next:
> +		opinfo_put(opinfo);
> +		rcu_read_lock();
> +	}
> +	rcu_read_unlock();
> +
> +out:
> +	read_unlock(&lease_list_lock);
> +	return err;
> +}
> +
> +static void copy_lease(struct oplock_info *op1, struct oplock_info *op2)
> +{
> +	struct lease *lease1 = op1->o_lease;
> +	struct lease *lease2 = op2->o_lease;
> +
> +	op2->level = op1->level;
> +	lease2->state = lease1->state;
> +	memcpy(lease2->lease_key, lease1->lease_key,
> +		SMB2_LEASE_KEY_SIZE);
> +	lease2->duration = lease1->duration;
> +	lease2->flags = lease1->flags;
> +}
> +
> +static int add_lease_global_list(struct oplock_info *opinfo)
> +{
> +	struct lease_table *lb;
> +
> +	read_lock(&lease_list_lock);
> +	list_for_each_entry(lb, &lease_table_list, l_entry) {
> +		if (!memcmp(lb->client_guid, opinfo->conn->ClientGUID,
> +			    SMB2_CLIENT_GUID_SIZE)) {
> +			opinfo->o_lease->l_lb = lb;
> +			lease_add_list(opinfo);
> +			read_unlock(&lease_list_lock);
> +			return 0;
> +		}
> +	}
> +	read_unlock(&lease_list_lock);
> +
> +	lb = kmalloc(sizeof(struct lease_table), GFP_KERNEL);
> +	if (!lb)
> +		return -ENOMEM;
> +
> +	memcpy(lb->client_guid, opinfo->conn->ClientGUID,
> +			SMB2_CLIENT_GUID_SIZE);
> +	INIT_LIST_HEAD(&lb->lease_list);
> +	spin_lock_init(&lb->lb_lock);
> +	opinfo->o_lease->l_lb = lb;
> +	lease_add_list(opinfo);
> +	lb_add(lb);
> +	return 0;
> +}
> +
> +static void set_oplock_level(struct oplock_info *opinfo, int level,
> +		struct lease_ctx_info *lctx)
> +{
> +	switch (level) {
> +	case SMB2_OPLOCK_LEVEL_BATCH:
> +	case SMB2_OPLOCK_LEVEL_EXCLUSIVE:
> +		grant_write_oplock(opinfo, level, lctx);
> +		break;
> +	case SMB2_OPLOCK_LEVEL_II:
> +		grant_read_oplock(opinfo, lctx);
> +		break;
> +	default:
> +		grant_none_oplock(opinfo, lctx);
> +		break;
> +	}
> +}
> +
> +/**
> + * smb_grant_oplock() - handle oplock/lease request on file open
> + * @work:		smb work
> + * @req_op_level:	oplock level
> + * @pid:		id of open file
> + * @fp:			ksmbd file pointer
> + * @tid:		Tree id of connection
> + * @lctx:		lease context information on file open
> + * @share_ret:		share mode
> + *
> + * Return:      0 on success, otherwise error
> + */
> +int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid,
> +		struct ksmbd_file *fp, __u16 tid, struct lease_ctx_info *lctx,
> +		int share_ret)
> +{
> +	struct ksmbd_session *sess = work->sess;
> +	int err = 0;
> +	struct oplock_info *opinfo = NULL, *prev_opinfo = NULL;
> +	struct ksmbd_inode *ci = fp->f_ci;
> +	bool prev_op_has_lease;
> +	__le32 prev_op_state = 0;
> +
> +	/* not support directory lease */
> +	if (S_ISDIR(file_inode(fp->filp)->i_mode)) {
> +		if (lctx)
> +			lctx->dlease = 1;
> +		return 0;
> +	}
> +
> +	opinfo = alloc_opinfo(work, pid, tid);
> +	if (!opinfo)
> +		return -ENOMEM;
> +
> +	if (lctx) {
> +		err = alloc_lease(opinfo, lctx);
> +		if (err)
> +			goto err_out;
> +		opinfo->is_lease = 1;
> +	}
> +
> +	/* ci does not have any oplock */
> +	if (!opinfo_count(fp))
> +		goto set_lev;
> +
> +	/* grant none-oplock if second open is trunc */
> +	if (ATTR_FP(fp)) {
> +		req_op_level = SMB2_OPLOCK_LEVEL_NONE;
> +		goto set_lev;
> +	}
> +
> +	if (lctx) {
> +		struct oplock_info *m_opinfo;
> +
> +		/* is lease already granted ? */
> +		m_opinfo = same_client_has_lease(ci, sess->conn->ClientGUID,
> +			lctx);
> +		if (m_opinfo) {
> +			copy_lease(m_opinfo, opinfo);
> +			if (atomic_read(&m_opinfo->breaking_cnt))
> +				opinfo->o_lease->flags =
> +					SMB2_LEASE_FLAG_BREAK_IN_PROGRESS_LE;
> +			goto out;
> +		}
> +	}
> +	prev_opinfo = opinfo_get_list(ci);
> +	if (!prev_opinfo ||
> +	    (prev_opinfo->level == SMB2_OPLOCK_LEVEL_NONE && lctx))
> +		goto set_lev;
> +	prev_op_has_lease = prev_opinfo->is_lease;
> +	if (prev_op_has_lease)
> +		prev_op_state = prev_opinfo->o_lease->state;
> +
> +	if (share_ret < 0 &&
> +	    prev_opinfo->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
> +		err = share_ret;
> +		opinfo_put(prev_opinfo);
> +		goto err_out;
> +	}
> +
> +	if (prev_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH &&
> +	    prev_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
> +		opinfo_put(prev_opinfo);
> +		goto op_break_not_needed;
> +	}
> +
> +	list_add(&work->interim_entry, &prev_opinfo->interim_list);
> +	err = oplock_break(prev_opinfo, SMB2_OPLOCK_LEVEL_II);
> +	opinfo_put(prev_opinfo);
> +	if (err == -ENOENT)
> +		goto set_lev;
> +	/* Check all oplock was freed by close */
> +	else if (err < 0)
> +		goto err_out;
> +
> +op_break_not_needed:
> +	if (share_ret < 0) {
> +		err = share_ret;
> +		goto err_out;
> +	}
> +
> +	if (req_op_level != SMB2_OPLOCK_LEVEL_NONE)
> +		req_op_level = SMB2_OPLOCK_LEVEL_II;
> +
> +	/* grant fixed oplock on stacked locking between lease and oplock */
> +	if (prev_op_has_lease && !lctx)
> +		if (prev_op_state & SMB2_LEASE_HANDLE_CACHING_LE)
> +			req_op_level = SMB2_OPLOCK_LEVEL_NONE;
> +
> +	if (!prev_op_has_lease && lctx) {
> +		req_op_level = SMB2_OPLOCK_LEVEL_II;
> +		lctx->req_state = SMB2_LEASE_READ_CACHING_LE;
> +	}
> +
> +set_lev:
> +	set_oplock_level(opinfo, req_op_level, lctx);
> +
> +out:
> +	rcu_assign_pointer(fp->f_opinfo, opinfo);
> +	opinfo->o_fp = fp;
> +
> +	opinfo_count_inc(fp);
> +	opinfo_add(opinfo);
> +	if (opinfo->is_lease) {
> +		err = add_lease_global_list(opinfo);
> +		if (err)
> +			goto err_out;
> +	}
> +
> +	return 0;
> +err_out:
> +	free_opinfo(opinfo);
> +	return err;
> +}
> +
> +/**
> + * smb_break_all_write_oplock() - break batch/exclusive oplock to level2
> + * @work:	smb work
> + * @fp:		ksmbd file pointer
> + * @is_trunc:	truncate on open
> + */
> +static void smb_break_all_write_oplock(struct ksmbd_work *work,
> +		struct ksmbd_file *fp, int is_trunc)
> +{
> +	struct oplock_info *brk_opinfo;
> +
> +	brk_opinfo = opinfo_get_list(fp->f_ci);
> +	if (!brk_opinfo)
> +		return;
> +	if (brk_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH &&
> +	    brk_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) {
> +		opinfo_put(brk_opinfo);
> +		return;
> +	}
> +
> +	brk_opinfo->open_trunc = is_trunc;
> +	list_add(&work->interim_entry, &brk_opinfo->interim_list);
> +	oplock_break(brk_opinfo, SMB2_OPLOCK_LEVEL_II);
> +	opinfo_put(brk_opinfo);
> +}
> +
> +/**
> + * smb_break_all_levII_oplock() - send level2 oplock or read lease break command
> + *	from server to client
> + * @work:	smb work
> + * @fp:		ksmbd file pointer
> + * @is_trunc:	truncate on open
> + */
> +void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp,
> +		int is_trunc)
> +{
> +	struct oplock_info *op, *brk_op;
> +	struct ksmbd_inode *ci;
> +	struct ksmbd_conn *conn = work->sess->conn;
> +
> +	if (!test_share_config_flag(work->tcon->share_conf,
> +				    KSMBD_SHARE_FLAG_OPLOCKS))
> +		return;
> +
> +	ci = fp->f_ci;
> +	op = opinfo_get(fp);
> +
> +	rcu_read_lock();
> +	list_for_each_entry_rcu(brk_op, &ci->m_op_list, op_entry) {
> +		if (!atomic_inc_not_zero(&brk_op->refcount))
> +			continue;
> +		rcu_read_unlock();
> +		if (brk_op->is_lease && (brk_op->o_lease->state &
> +		    (~(SMB2_LEASE_READ_CACHING_LE |
> +				SMB2_LEASE_HANDLE_CACHING_LE)))) {
> +			ksmbd_debug(OPLOCK, "unexpected lease state(0x%x)\n",
> +					brk_op->o_lease->state);
> +			goto next;
> +		} else if (brk_op->level !=
> +				SMB2_OPLOCK_LEVEL_II) {
> +			ksmbd_debug(OPLOCK, "unexpected oplock(0x%x)\n",
> +					brk_op->level);
> +			goto next;
> +		}
> +
> +		/* Skip oplock being break to none */
> +		if (brk_op->is_lease && (brk_op->o_lease->new_state ==
> +				SMB2_LEASE_NONE_LE) &&
> +		    atomic_read(&brk_op->breaking_cnt))
> +			goto next;
> +
> +		if (op && op->is_lease && brk_op->is_lease &&
> +		    !memcmp(conn->ClientGUID, brk_op->conn->ClientGUID,
> +			    SMB2_CLIENT_GUID_SIZE) &&
> +		    !memcmp(op->o_lease->lease_key, brk_op->o_lease->lease_key,
> +			    SMB2_LEASE_KEY_SIZE))
> +			goto next;
> +		brk_op->open_trunc = is_trunc;
> +		oplock_break(brk_op, SMB2_OPLOCK_LEVEL_NONE);
> +next:
> +		opinfo_put(brk_op);
> +		rcu_read_lock();
> +	}
> +	rcu_read_unlock();
> +
> +	if (op)
> +		opinfo_put(op);
> +}
> +
> +/**
> + * smb_break_all_oplock() - break both batch/exclusive and level2 oplock
> + * @work:	smb work
> + * @fp:		ksmbd file pointer
> + */
> +void smb_break_all_oplock(struct ksmbd_work *work, struct ksmbd_file *fp)
> +{
> +	if (!test_share_config_flag(work->tcon->share_conf,
> +				    KSMBD_SHARE_FLAG_OPLOCKS))
> +		return;
> +
> +	smb_break_all_write_oplock(work, fp, 1);
> +	smb_break_all_levII_oplock(work, fp, 1);
> +}
> +
> +/**
> + * smb2_map_lease_to_oplock() - map lease state to corresponding oplock type
> + * @lease_state:     lease type
> + *
> + * Return:      0 if no mapping, otherwise corresponding oplock type
> + */
> +__u8 smb2_map_lease_to_oplock(__le32 lease_state)
> +{
> +	if (lease_state == (SMB2_LEASE_HANDLE_CACHING_LE |
> +			    SMB2_LEASE_READ_CACHING_LE |
> +			    SMB2_LEASE_WRITE_CACHING_LE)) {
> +		return SMB2_OPLOCK_LEVEL_BATCH;
> +	} else if (lease_state != SMB2_LEASE_WRITE_CACHING_LE &&
> +		 lease_state & SMB2_LEASE_WRITE_CACHING_LE) {
> +		if (!(lease_state & SMB2_LEASE_HANDLE_CACHING_LE))
> +			return SMB2_OPLOCK_LEVEL_EXCLUSIVE;
> +	} else if (lease_state & SMB2_LEASE_READ_CACHING_LE) {
> +		return SMB2_OPLOCK_LEVEL_II;
> +	}
> +	return 0;
> +}
> +
> +/**
> + * create_lease_buf() - create lease context for open cmd response
> + * @rbuf:	buffer to create lease context response
> + * @lease:	buffer to stored parsed lease state information
> + */
> +void create_lease_buf(u8 *rbuf, struct lease *lease)
> +{
> +	struct create_lease *buf = (struct create_lease *)rbuf;
> +	char *LeaseKey = (char *)&lease->lease_key;
> +
> +	memset(buf, 0, sizeof(struct create_lease));
> +	buf->lcontext.LeaseKeyLow = *((__le64 *)LeaseKey);
> +	buf->lcontext.LeaseKeyHigh = *((__le64 *)(LeaseKey + 8));
> +	buf->lcontext.LeaseFlags = lease->flags;
> +	buf->lcontext.LeaseState = lease->state;
> +	buf->ccontext.DataOffset = cpu_to_le16(offsetof
> +					(struct create_lease, lcontext));
> +	buf->ccontext.DataLength = cpu_to_le32(sizeof(struct lease_context));
> +	buf->ccontext.NameOffset = cpu_to_le16(offsetof
> +				(struct create_lease, Name));
> +	buf->ccontext.NameLength = cpu_to_le16(4);
> +	buf->Name[0] = 'R';
> +	buf->Name[1] = 'q';
> +	buf->Name[2] = 'L';
> +	buf->Name[3] = 's';
> +}
> +
> +/**
> + * parse_lease_state() - parse lease context containted in file open request
> + * @open_req:	buffer containing smb2 file open(create) request
> + *
> + * Return:  oplock state, -ENOENT if create lease context not found
> + */
> +struct lease_ctx_info *parse_lease_state(void *open_req)
> +{
> +	char *data_offset;
> +	struct create_context *cc;
> +	unsigned int next = 0;
> +	char *name;
> +	bool found = false;
> +	struct smb2_create_req *req = (struct smb2_create_req *)open_req;
> +	struct lease_ctx_info *lreq = kzalloc(sizeof(struct lease_ctx_info),
> +		GFP_KERNEL);
> +	if (!lreq)
> +		return NULL;
> +
> +	data_offset = (char *)req + 4 + le32_to_cpu(req->CreateContextsOffset);
> +	cc = (struct create_context *)data_offset;
> +	do {
> +		cc = (struct create_context *)((char *)cc + next);
> +		name = le16_to_cpu(cc->NameOffset) + (char *)cc;
> +		if (le16_to_cpu(cc->NameLength) != 4 ||
> +		    strncmp(name, SMB2_CREATE_REQUEST_LEASE, 4)) {
> +			next = le32_to_cpu(cc->Next);
> +			continue;
> +		}
> +		found = true;
> +		break;
> +	} while (next != 0);
> +
> +	if (found) {
> +		struct create_lease *lc = (struct create_lease *)cc;
> +		*((__le64 *)lreq->lease_key) = lc->lcontext.LeaseKeyLow;
> +		*((__le64 *)(lreq->lease_key + 8)) = lc->lcontext.LeaseKeyHigh;
> +		lreq->req_state = lc->lcontext.LeaseState;
> +		lreq->flags = lc->lcontext.LeaseFlags;
> +		lreq->duration = lc->lcontext.LeaseDuration;
> +		return lreq;
> +	}
> +
> +	kfree(lreq);
> +	return NULL;
> +}
> +
> +/**
> + * smb2_find_context_vals() - find a particular context info in open request
> + * @open_req:	buffer containing smb2 file open(create) request
> + * @tag:	context name to search for
> + *
> + * Return:      pointer to requested context, NULL if @str context not found
> + */
> +struct create_context *smb2_find_context_vals(void *open_req, const char *tag)
> +{
> +	char *data_offset;
> +	struct create_context *cc;
> +	unsigned int next = 0;
> +	char *name;
> +	struct smb2_create_req *req = (struct smb2_create_req *)open_req;
> +
> +	data_offset = (char *)req + 4 + le32_to_cpu(req->CreateContextsOffset);
> +	cc = (struct create_context *)data_offset;
> +	do {
> +		int val;
> +
> +		cc = (struct create_context *)((char *)cc + next);
> +		name = le16_to_cpu(cc->NameOffset) + (char *)cc;
> +		val = le16_to_cpu(cc->NameLength);
> +		if (val < 4)
> +			return ERR_PTR(-EINVAL);
> +
> +		if (memcmp(name, tag, val) == 0)
> +			return cc;
> +		next = le32_to_cpu(cc->Next);
> +	} while (next != 0);
> +
> +	return ERR_PTR(-ENOENT);
> +}
> +
> +/**
> + * create_durable_rsp_buf() - create durable handle context
> + * @cc:	buffer to create durable context response
> + */
> +void create_durable_rsp_buf(char *cc)
> +{
> +	struct create_durable_rsp *buf;
> +
> +	buf = (struct create_durable_rsp *)cc;
> +	memset(buf, 0, sizeof(struct create_durable_rsp));
> +	buf->ccontext.DataOffset = cpu_to_le16(offsetof
> +			(struct create_durable_rsp, Data));
> +	buf->ccontext.DataLength = cpu_to_le32(8);
> +	buf->ccontext.NameOffset = cpu_to_le16(offsetof
> +			(struct create_durable_rsp, Name));
> +	buf->ccontext.NameLength = cpu_to_le16(4);
> +	/* SMB2_CREATE_DURABLE_HANDLE_RESPONSE is "DHnQ" */
> +	buf->Name[0] = 'D';
> +	buf->Name[1] = 'H';
> +	buf->Name[2] = 'n';
> +	buf->Name[3] = 'Q';
> +}
> +
> +/**
> + * create_durable_v2_rsp_buf() - create durable handle v2 context
> + * @cc:	buffer to create durable context response
> + * @fp: ksmbd file pointer
> + */
> +void create_durable_v2_rsp_buf(char *cc, struct ksmbd_file *fp)
> +{
> +	struct create_durable_v2_rsp *buf;
> +
> +	buf = (struct create_durable_v2_rsp *)cc;
> +	memset(buf, 0, sizeof(struct create_durable_rsp));
> +	buf->ccontext.DataOffset = cpu_to_le16(offsetof
> +			(struct create_durable_rsp, Data));
> +	buf->ccontext.DataLength = cpu_to_le32(8);
> +	buf->ccontext.NameOffset = cpu_to_le16(offsetof
> +			(struct create_durable_rsp, Name));
> +	buf->ccontext.NameLength = cpu_to_le16(4);
> +	/* SMB2_CREATE_DURABLE_HANDLE_RESPONSE_V2 is "DH2Q" */
> +	buf->Name[0] = 'D';
> +	buf->Name[1] = 'H';
> +	buf->Name[2] = '2';
> +	buf->Name[3] = 'Q';
> +
> +	buf->Timeout = cpu_to_le32(fp->durable_timeout);
> +}
> +
> +/**
> + * create_mxac_rsp_buf() - create query maximal access context
> + * @cc:			buffer to create maximal access context response
> + * @maximal_access:	maximal access
> + */
> +void create_mxac_rsp_buf(char *cc, int maximal_access)
> +{
> +	struct create_mxac_rsp *buf;
> +
> +	buf = (struct create_mxac_rsp *)cc;
> +	memset(buf, 0, sizeof(struct create_mxac_rsp));
> +	buf->ccontext.DataOffset = cpu_to_le16(offsetof
> +			(struct create_mxac_rsp, QueryStatus));
> +	buf->ccontext.DataLength = cpu_to_le32(8);
> +	buf->ccontext.NameOffset = cpu_to_le16(offsetof
> +			(struct create_mxac_rsp, Name));
> +	buf->ccontext.NameLength = cpu_to_le16(4);
> +	/* SMB2_CREATE_QUERY_MAXIMAL_ACCESS_RESPONSE is "MxAc" */
> +	buf->Name[0] = 'M';
> +	buf->Name[1] = 'x';
> +	buf->Name[2] = 'A';
> +	buf->Name[3] = 'c';
> +
> +	buf->QueryStatus = STATUS_SUCCESS;
> +	buf->MaximalAccess = cpu_to_le32(maximal_access);
> +}
> +
> +void create_disk_id_rsp_buf(char *cc, __u64 file_id, __u64 vol_id)
> +{
> +	struct create_disk_id_rsp *buf;
> +
> +	buf = (struct create_disk_id_rsp *)cc;
> +	memset(buf, 0, sizeof(struct create_disk_id_rsp));
> +	buf->ccontext.DataOffset = cpu_to_le16(offsetof
> +			(struct create_disk_id_rsp, DiskFileId));
> +	buf->ccontext.DataLength = cpu_to_le32(32);
> +	buf->ccontext.NameOffset = cpu_to_le16(offsetof
> +			(struct create_mxac_rsp, Name));
> +	buf->ccontext.NameLength = cpu_to_le16(4);
> +	/* SMB2_CREATE_QUERY_ON_DISK_ID_RESPONSE is "QFid" */
> +	buf->Name[0] = 'Q';
> +	buf->Name[1] = 'F';
> +	buf->Name[2] = 'i';
> +	buf->Name[3] = 'd';
> +
> +	buf->DiskFileId = cpu_to_le64(file_id);
> +	buf->VolumeId = cpu_to_le64(vol_id);
> +}
> +
> +/**
> + * create_posix_rsp_buf() - create posix extension context
> + * @cc:	buffer to create posix on posix response
> + * @fp: ksmbd file pointer
> + */
> +void create_posix_rsp_buf(char *cc, struct ksmbd_file *fp)
> +{
> +	struct create_posix_rsp *buf;
> +	struct inode *inode = FP_INODE(fp);
> +
> +	buf = (struct create_posix_rsp *)cc;
> +	memset(buf, 0, sizeof(struct create_posix_rsp));
> +	buf->ccontext.DataOffset = cpu_to_le16(offsetof
> +			(struct create_posix_rsp, nlink));
> +	buf->ccontext.DataLength = cpu_to_le32(52);
> +	buf->ccontext.NameOffset = cpu_to_le16(offsetof
> +			(struct create_posix_rsp, Name));
> +	buf->ccontext.NameLength = cpu_to_le16(POSIX_CTXT_DATA_LEN);
> +	/* SMB2_CREATE_TAG_POSIX is "0x93AD25509CB411E7B42383DE968BCD7C" */
> +	buf->Name[0] = 0x93;
> +	buf->Name[1] = 0xAD;
> +	buf->Name[2] = 0x25;
> +	buf->Name[3] = 0x50;
> +	buf->Name[4] = 0x9C;
> +	buf->Name[5] = 0xB4;
> +	buf->Name[6] = 0x11;
> +	buf->Name[7] = 0xE7;
> +	buf->Name[8] = 0xB4;
> +	buf->Name[9] = 0x23;
> +	buf->Name[10] = 0x83;
> +	buf->Name[11] = 0xDE;
> +	buf->Name[12] = 0x96;
> +	buf->Name[13] = 0x8B;
> +	buf->Name[14] = 0xCD;
> +	buf->Name[15] = 0x7C;
> +
> +	buf->nlink = cpu_to_le32(inode->i_nlink);
> +	buf->reparse_tag = cpu_to_le32(fp->volatile_id);
> +	buf->mode = cpu_to_le32(inode->i_mode);
> +	id_to_sid(from_kuid(&init_user_ns, inode->i_uid),
> +		SIDNFS_USER, (struct smb_sid *)&buf->SidBuffer[0]);
> +	id_to_sid(from_kgid(&init_user_ns, inode->i_gid),
> +		SIDNFS_GROUP, (struct smb_sid *)&buf->SidBuffer[20]);
> +}
> +
> +/*
> + * Find lease object(opinfo) for given lease key/fid from lease
> + * break/file close path.
> + */
> +/**
> + * lookup_lease_in_table() - find a matching lease info object
> + * @conn:	connection instance
> + * @lease_key:	lease key to be searched for
> + *
> + * Return:      opinfo if found matching opinfo, otherwise NULL
> + */
> +struct oplock_info *lookup_lease_in_table(struct ksmbd_conn *conn,
> +		char *lease_key)
> +{
> +	struct oplock_info *opinfo = NULL, *ret_op = NULL;
> +	struct lease_table *lt;
> +	int ret;
> +
> +	read_lock(&lease_list_lock);
> +	list_for_each_entry(lt, &lease_table_list, l_entry) {
> +		if (!memcmp(lt->client_guid, conn->ClientGUID,
> +			    SMB2_CLIENT_GUID_SIZE))
> +			goto found;
> +	}
> +
> +	read_unlock(&lease_list_lock);
> +	return NULL;
> +
> +found:
> +	rcu_read_lock();
> +	list_for_each_entry_rcu(opinfo, &lt->lease_list, lease_entry) {
> +		if (!atomic_inc_not_zero(&opinfo->refcount))
> +			continue;
> +		rcu_read_unlock();
> +		if (!opinfo->op_state || opinfo->op_state == OPLOCK_CLOSING)
> +			goto op_next;
> +		if (!(opinfo->o_lease->state &
> +		      (SMB2_LEASE_HANDLE_CACHING_LE |
> +		       SMB2_LEASE_WRITE_CACHING_LE)))
> +			goto op_next;
> +		ret = compare_guid_key(opinfo, conn->ClientGUID,
> +			lease_key);
> +		if (ret) {
> +			ksmbd_debug(OPLOCK, "found opinfo\n");
> +			ret_op = opinfo;
> +			goto out;
> +		}
> +op_next:
> +		opinfo_put(opinfo);
> +		rcu_read_lock();
> +	}
> +	rcu_read_unlock();
> +
> +out:
> +	read_unlock(&lease_list_lock);
> +	return ret_op;
> +}
> +
> +int smb2_check_durable_oplock(struct ksmbd_file *fp,
> +		struct lease_ctx_info *lctx, char *name)
> +{
> +	struct oplock_info *opinfo = opinfo_get(fp);
> +	int ret = 0;
> +
> +	if (opinfo && opinfo->is_lease) {
> +		if (!lctx) {
> +			ksmbd_err("open does not include lease\n");
> +			ret = -EBADF;
> +			goto out;
> +		}
> +		if (memcmp(opinfo->o_lease->lease_key, lctx->lease_key,
> +			   SMB2_LEASE_KEY_SIZE)) {
> +			ksmbd_err("invalid lease key\n");
> +			ret = -EBADF;
> +			goto out;
> +		}
> +		if (name && strcmp(fp->filename, name)) {
> +			ksmbd_err("invalid name reconnect %s\n", name);
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +	}
> +out:
> +	if (opinfo)
> +		opinfo_put(opinfo);
> +	return ret;
> +}
> diff --git a/fs/cifsd/oplock.h b/fs/cifsd/oplock.h
> new file mode 100644
> index 000000000000..f8b4b486eb93
> --- /dev/null
> +++ b/fs/cifsd/oplock.h
> @@ -0,0 +1,133 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + *   Copyright (C) 2016 Namjae Jeon <linkinjeon@xxxxxxxxxx>
> + *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
> + */
> +
> +#ifndef __KSMBD_OPLOCK_H
> +#define __KSMBD_OPLOCK_H
> +
> +#include "smb_common.h"
> +
> +#define OPLOCK_WAIT_TIME	(35 * HZ)
> +
> +/* SMB Oplock levels */
> +#define OPLOCK_NONE      0
> +#define OPLOCK_EXCLUSIVE 1
> +#define OPLOCK_BATCH     2
> +#define OPLOCK_READ      3  /* level 2 oplock */
> +
> +/* SMB2 Oplock levels */
> +#define SMB2_OPLOCK_LEVEL_NONE          0x00
> +#define SMB2_OPLOCK_LEVEL_II            0x01
> +#define SMB2_OPLOCK_LEVEL_EXCLUSIVE     0x08
> +#define SMB2_OPLOCK_LEVEL_BATCH         0x09
> +#define SMB2_OPLOCK_LEVEL_LEASE         0xFF
> +
> +/* Oplock states */
> +#define OPLOCK_STATE_NONE	0x00
> +#define OPLOCK_ACK_WAIT		0x01
> +#define OPLOCK_CLOSING		0x02
> +
> +#define OPLOCK_WRITE_TO_READ		0x01
> +#define OPLOCK_READ_HANDLE_TO_READ	0x02
> +#define OPLOCK_WRITE_TO_NONE		0x04
> +#define OPLOCK_READ_TO_NONE		0x08
> +
> +#define SMB2_LEASE_KEY_SIZE		16
> +
> +struct lease_ctx_info {
> +	__u8	lease_key[SMB2_LEASE_KEY_SIZE];
> +	__le32	req_state;
> +	__le32	flags;
> +	__le64	duration;
> +	int dlease;
> +};
> +
> +struct lease_table {
> +	char			client_guid[SMB2_CLIENT_GUID_SIZE];
> +	struct list_head	lease_list;
> +	struct list_head	l_entry;
> +	spinlock_t		lb_lock;
> +};
> +
> +struct lease {
> +	__u8			lease_key[SMB2_LEASE_KEY_SIZE];
> +	__le32			state;
> +	__le32			new_state;
> +	__le32			flags;
> +	__le64			duration;
> +	struct lease_table	*l_lb;
> +};
> +
> +struct oplock_info {
> +	struct ksmbd_conn	*conn;
> +	struct ksmbd_session	*sess;
> +	struct ksmbd_work	*work;
> +	struct ksmbd_file	*o_fp;
> +	int                     level;
> +	int                     op_state;
> +	unsigned long		pending_break;
> +	u64			fid;
> +	atomic_t		breaking_cnt;
> +	atomic_t		refcount;
> +	__u16                   Tid;
> +	bool			is_lease;
> +	bool			open_trunc;	/* truncate on open */
> +	struct lease		*o_lease;
> +	struct list_head        interim_list;
> +	struct list_head        op_entry;
> +	struct list_head        lease_entry;
> +	wait_queue_head_t oplock_q; /* Other server threads */
> +	wait_queue_head_t oplock_brk; /* oplock breaking wait */
> +	struct rcu_head		rcu_head;
> +};
> +
> +struct lease_break_info {
> +	__le32			curr_state;
> +	__le32			new_state;
> +	char			lease_key[SMB2_LEASE_KEY_SIZE];
> +};
> +
> +struct oplock_break_info {
> +	int level;
> +	int open_trunc;
> +	int fid;
> +};
> +
> +int smb_grant_oplock(struct ksmbd_work *work, int req_op_level,
> +		u64 pid, struct ksmbd_file *fp, __u16 tid,
> +		struct lease_ctx_info *lctx, int share_ret);
> +void smb_break_all_levII_oplock(struct ksmbd_work *work,
> +		struct ksmbd_file *fp, int is_trunc);
> +
> +int opinfo_write_to_read(struct oplock_info *opinfo);
> +int opinfo_read_handle_to_read(struct oplock_info *opinfo);
> +int opinfo_write_to_none(struct oplock_info *opinfo);
> +int opinfo_read_to_none(struct oplock_info *opinfo);
> +void close_id_del_oplock(struct ksmbd_file *fp);
> +void smb_break_all_oplock(struct ksmbd_work *work, struct ksmbd_file *fp);
> +struct oplock_info *opinfo_get(struct ksmbd_file *fp);
> +void opinfo_put(struct oplock_info *opinfo);
> +
> +/* Lease related functions */
> +void create_lease_buf(u8 *rbuf, struct lease *lease);
> +struct lease_ctx_info *parse_lease_state(void *open_req);
> +__u8 smb2_map_lease_to_oplock(__le32 lease_state);
> +int lease_read_to_write(struct oplock_info *opinfo);
> +
> +/* Durable related functions */
> +void create_durable_rsp_buf(char *cc);
> +void create_durable_v2_rsp_buf(char *cc, struct ksmbd_file *fp);
> +void create_mxac_rsp_buf(char *cc, int maximal_access);
> +void create_disk_id_rsp_buf(char *cc, __u64 file_id, __u64 vol_id);
> +void create_posix_rsp_buf(char *cc, struct ksmbd_file *fp);
> +struct create_context *smb2_find_context_vals(void *open_req, const char *str);
> +struct oplock_info *lookup_lease_in_table(struct ksmbd_conn *conn,
> +		char *lease_key);
> +int find_same_lease_key(struct ksmbd_session *sess, struct ksmbd_inode *ci,
> +		struct lease_ctx_info *lctx);
> +void destroy_lease_table(struct ksmbd_conn *conn);
> +int smb2_check_durable_oplock(struct ksmbd_file *fp,
> +		struct lease_ctx_info *lctx, char *name);
> +#endif /* __KSMBD_OPLOCK_H */
> -- 
> 2.17.1
>