#include <linux/ceph/auth.h>
#include <linux/ceph/debugfs.h>
+#define RECONNECT_MAX_SIZE (INT_MAX - PAGE_SIZE)
+
/*
* A cluster of MDS (metadata server) daemons is responsible for
* managing the file system namespace (the directory hierarchy and
*/
struct ceph_reconnect_state {
- int nr_caps;
+ struct ceph_mds_session *session;
+ int nr_caps, nr_realms;
struct ceph_pagelist *pagelist;
unsigned msg_version;
+ bool allow_multi;
};
static void __wake_requests(struct ceph_mds_client *mdsc,
dout("removing cap %p, ci is %p, inode is %p\n",
cap, ci, &ci->vfs_inode);
spin_lock(&ci->i_ceph_lock);
+ if (cap->mds_wanted | cap->issued)
+ ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
__ceph_remove_cap(cap, false);
if (!ci->i_auth_cap) {
struct ceph_cap_flush *cf;
struct ceph_mds_client *mdsc = fsc->mdsc;
- ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
-
if (ci->i_wrbuffer_ref > 0 &&
READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
invalidate = true;
dispose_cap_releases(session->s_mdsc, &dispose);
}
+enum {
+ RECONNECT,
+ RENEWCAPS,
+ FORCE_RO,
+};
+
/*
* wake up any threads waiting on this session's caps. if the cap is
* old (didn't get renewed on the client reconnect), remove it now.
void *arg)
{
struct ceph_inode_info *ci = ceph_inode(inode);
+ unsigned long ev = (unsigned long)arg;
- if (arg) {
+ if (ev == RECONNECT) {
spin_lock(&ci->i_ceph_lock);
ci->i_wanted_max_size = 0;
ci->i_requested_max_size = 0;
spin_unlock(&ci->i_ceph_lock);
+ } else if (ev == RENEWCAPS) {
+ if (cap->cap_gen < cap->session->s_cap_gen) {
+ /* mds did not re-issue stale cap */
+ spin_lock(&ci->i_ceph_lock);
+ cap->issued = cap->implemented = CEPH_CAP_PIN;
+ /* make sure mds knows what we want */
+ if (__ceph_caps_file_wanted(ci) & ~cap->mds_wanted)
+ ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
+ spin_unlock(&ci->i_ceph_lock);
+ }
+ } else if (ev == FORCE_RO) {
}
wake_up_all(&ci->i_cap_wq);
return 0;
}
-static void wake_up_session_caps(struct ceph_mds_session *session,
- int reconnect)
+static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
{
dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
iterate_session_caps(session, wake_up_session_cb,
- (void *)(unsigned long)reconnect);
+ (void *)(unsigned long)ev);
}
/*
spin_unlock(&session->s_cap_lock);
if (wake)
- wake_up_session_caps(session, 0);
+ wake_up_session_caps(session, RENEWCAPS);
}
/*
pr_err("mdsc_handle_forward decode error err=%d\n", err);
}
+static int __decode_and_drop_session_metadata(void **p, void *end)
+{
+ /* map<string,string> */
+ u32 n;
+ ceph_decode_32_safe(p, end, n, bad);
+ while (n-- > 0) {
+ u32 len;
+ ceph_decode_32_safe(p, end, len, bad);
+ ceph_decode_need(p, end, len, bad);
+ *p += len;
+ ceph_decode_32_safe(p, end, len, bad);
+ ceph_decode_need(p, end, len, bad);
+ *p += len;
+ }
+ return 0;
+bad:
+ return -1;
+}
+
/*
* handle a mds session control message
*/
struct ceph_msg *msg)
{
struct ceph_mds_client *mdsc = session->s_mdsc;
+ int mds = session->s_mds;
+ int msg_version = le16_to_cpu(msg->hdr.version);
+ void *p = msg->front.iov_base;
+ void *end = p + msg->front.iov_len;
+ struct ceph_mds_session_head *h;
u32 op;
u64 seq;
- int mds = session->s_mds;
- struct ceph_mds_session_head *h = msg->front.iov_base;
+ unsigned long features = 0;
int wake = 0;
/* decode */
- if (msg->front.iov_len < sizeof(*h))
- goto bad;
+ ceph_decode_need(&p, end, sizeof(*h), bad);
+ h = p;
+ p += sizeof(*h);
+
op = le32_to_cpu(h->op);
seq = le64_to_cpu(h->seq);
+ if (msg_version >= 3) {
+ u32 len;
+ /* version >= 2, metadata */
+ if (__decode_and_drop_session_metadata(&p, end) < 0)
+ goto bad;
+ /* version >= 3, feature bits */
+ ceph_decode_32_safe(&p, end, len, bad);
+ ceph_decode_need(&p, end, len, bad);
+ memcpy(&features, p, min_t(size_t, len, sizeof(features)));
+ p += len;
+ }
+
mutex_lock(&mdsc->mutex);
if (op == CEPH_SESSION_CLOSE) {
get_session(session);
if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
pr_info("mds%d reconnect success\n", session->s_mds);
session->s_state = CEPH_MDS_SESSION_OPEN;
+ session->s_features = features;
renewed_caps(mdsc, session, 0);
wake = 1;
if (mdsc->stopping)
spin_lock(&session->s_cap_lock);
session->s_readonly = true;
spin_unlock(&session->s_cap_lock);
- wake_up_session_caps(session, 0);
+ wake_up_session_caps(session, FORCE_RO);
break;
case CEPH_SESSION_REJECT:
mutex_unlock(&mdsc->mutex);
}
+static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
+{
+ struct ceph_msg *reply;
+ struct ceph_pagelist *_pagelist;
+ struct page *page;
+ __le32 *addr;
+ int err = -ENOMEM;
+
+ if (!recon_state->allow_multi)
+ return -ENOSPC;
+
+ /* can't handle message that contains both caps and realm */
+ BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
+
+ /* pre-allocate new pagelist */
+ _pagelist = ceph_pagelist_alloc(GFP_NOFS);
+ if (!_pagelist)
+ return -ENOMEM;
+
+ reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
+ if (!reply)
+ goto fail_msg;
+
+ /* placeholder for nr_caps */
+ err = ceph_pagelist_encode_32(_pagelist, 0);
+ if (err < 0)
+ goto fail;
+
+ if (recon_state->nr_caps) {
+ /* currently encoding caps */
+ err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
+ if (err)
+ goto fail;
+ } else {
+ /* placeholder for nr_realms (currently encoding relams) */
+ err = ceph_pagelist_encode_32(_pagelist, 0);
+ if (err < 0)
+ goto fail;
+ }
+
+ err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
+ if (err)
+ goto fail;
+
+ page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
+ addr = kmap_atomic(page);
+ if (recon_state->nr_caps) {
+ /* currently encoding caps */
+ *addr = cpu_to_le32(recon_state->nr_caps);
+ } else {
+ /* currently encoding relams */
+ *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
+ }
+ kunmap_atomic(addr);
+
+ reply->hdr.version = cpu_to_le16(5);
+ reply->hdr.compat_version = cpu_to_le16(4);
+
+ reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
+ ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
+
+ ceph_con_send(&recon_state->session->s_con, reply);
+ ceph_pagelist_release(recon_state->pagelist);
+
+ recon_state->pagelist = _pagelist;
+ recon_state->nr_caps = 0;
+ recon_state->nr_realms = 0;
+ recon_state->msg_version = 5;
+ return 0;
+fail:
+ ceph_msg_put(reply);
+fail_msg:
+ ceph_pagelist_release(_pagelist);
+ return err;
+}
+
/*
* Encode information about a cap for a reconnect with the MDS.
*/
struct ceph_inode_info *ci = cap->ci;
struct ceph_reconnect_state *recon_state = arg;
struct ceph_pagelist *pagelist = recon_state->pagelist;
- char *path;
- int pathlen, err;
- u64 pathbase;
+ int err;
u64 snap_follows;
- struct dentry *dentry;
dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
inode, ceph_vinop(inode), cap, cap->cap_id,
ceph_cap_string(cap->issued));
- err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
- if (err)
- return err;
-
- dentry = d_find_alias(inode);
- if (dentry) {
- path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
- if (IS_ERR(path)) {
- err = PTR_ERR(path);
- goto out_dput;
- }
- } else {
- path = NULL;
- pathlen = 0;
- pathbase = 0;
- }
spin_lock(&ci->i_ceph_lock);
cap->seq = 0; /* reset cap seq */
rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
rec.v2.issued = cpu_to_le32(cap->issued);
rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
- rec.v2.pathbase = cpu_to_le64(pathbase);
+ rec.v2.pathbase = 0;
rec.v2.flock_len = (__force __le32)
((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
} else {
ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
- rec.v1.pathbase = cpu_to_le64(pathbase);
+ rec.v1.pathbase = 0;
}
if (list_empty(&ci->i_cap_snaps)) {
if (recon_state->msg_version >= 2) {
int num_fcntl_locks, num_flock_locks;
struct ceph_filelock *flocks = NULL;
- size_t struct_len, total_len = 0;
+ size_t struct_len, total_len = sizeof(u64);
u8 struct_v = 0;
encode_again:
GFP_NOFS);
if (!flocks) {
err = -ENOMEM;
- goto out_free;
+ goto out_err;
}
err = ceph_encode_locks_to_buffer(inode, flocks,
num_fcntl_locks,
flocks = NULL;
if (err == -ENOSPC)
goto encode_again;
- goto out_free;
+ goto out_err;
}
} else {
kfree(flocks);
if (recon_state->msg_version >= 3) {
/* version, compat_version and struct_len */
- total_len = 2 * sizeof(u8) + sizeof(u32);
+ total_len += 2 * sizeof(u8) + sizeof(u32);
struct_v = 2;
}
/*
sizeof(struct ceph_filelock);
rec.v2.flock_len = cpu_to_le32(struct_len);
- struct_len += sizeof(rec.v2);
- struct_len += sizeof(u32) + pathlen;
+ struct_len += sizeof(u32) + sizeof(rec.v2);
if (struct_v >= 2)
struct_len += sizeof(u64); /* snap_follows */
total_len += struct_len;
+
+ if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
+ err = send_reconnect_partial(recon_state);
+ if (err)
+ goto out_freeflocks;
+ pagelist = recon_state->pagelist;
+ }
+
err = ceph_pagelist_reserve(pagelist, total_len);
+ if (err)
+ goto out_freeflocks;
- if (!err) {
- if (recon_state->msg_version >= 3) {
- ceph_pagelist_encode_8(pagelist, struct_v);
- ceph_pagelist_encode_8(pagelist, 1);
- ceph_pagelist_encode_32(pagelist, struct_len);
- }
- ceph_pagelist_encode_string(pagelist, path, pathlen);
- ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
- ceph_locks_to_pagelist(flocks, pagelist,
- num_fcntl_locks,
- num_flock_locks);
- if (struct_v >= 2)
- ceph_pagelist_encode_64(pagelist, snap_follows);
+ ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
+ if (recon_state->msg_version >= 3) {
+ ceph_pagelist_encode_8(pagelist, struct_v);
+ ceph_pagelist_encode_8(pagelist, 1);
+ ceph_pagelist_encode_32(pagelist, struct_len);
}
+ ceph_pagelist_encode_string(pagelist, NULL, 0);
+ ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
+ ceph_locks_to_pagelist(flocks, pagelist,
+ num_fcntl_locks, num_flock_locks);
+ if (struct_v >= 2)
+ ceph_pagelist_encode_64(pagelist, snap_follows);
+out_freeflocks:
kfree(flocks);
} else {
- size_t size = sizeof(u32) + pathlen + sizeof(rec.v1);
- err = ceph_pagelist_reserve(pagelist, size);
- if (!err) {
- ceph_pagelist_encode_string(pagelist, path, pathlen);
- ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
+ u64 pathbase = 0;
+ int pathlen = 0;
+ char *path = NULL;
+ struct dentry *dentry;
+
+ dentry = d_find_alias(inode);
+ if (dentry) {
+ path = ceph_mdsc_build_path(dentry,
+ &pathlen, &pathbase, 0);
+ dput(dentry);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out_err;
+ }
+ rec.v1.pathbase = cpu_to_le64(pathbase);
+ }
+
+ err = ceph_pagelist_reserve(pagelist,
+ sizeof(u64) + sizeof(u32) +
+ pathlen + sizeof(rec.v1));
+ if (err) {
+ goto out_freepath;
}
+
+ ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
+ ceph_pagelist_encode_string(pagelist, path, pathlen);
+ ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
+out_freepath:
+ kfree(path);
}
- recon_state->nr_caps++;
-out_free:
- kfree(path);
-out_dput:
- dput(dentry);
+out_err:
+ if (err >= 0)
+ recon_state->nr_caps++;
+ return err;
+}
+
+static int encode_snap_realms(struct ceph_mds_client *mdsc,
+ struct ceph_reconnect_state *recon_state)
+{
+ struct rb_node *p;
+ struct ceph_pagelist *pagelist = recon_state->pagelist;
+ int err = 0;
+
+ if (recon_state->msg_version >= 4) {
+ err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
+ if (err < 0)
+ goto fail;
+ }
+
+ /*
+ * snaprealms. we provide mds with the ino, seq (version), and
+ * parent for all of our realms. If the mds has any newer info,
+ * it will tell us.
+ */
+ for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
+ struct ceph_snap_realm *realm =
+ rb_entry(p, struct ceph_snap_realm, node);
+ struct ceph_mds_snaprealm_reconnect sr_rec;
+
+ if (recon_state->msg_version >= 4) {
+ size_t need = sizeof(u8) * 2 + sizeof(u32) +
+ sizeof(sr_rec);
+
+ if (pagelist->length + need > RECONNECT_MAX_SIZE) {
+ err = send_reconnect_partial(recon_state);
+ if (err)
+ goto fail;
+ pagelist = recon_state->pagelist;
+ }
+
+ err = ceph_pagelist_reserve(pagelist, need);
+ if (err)
+ goto fail;
+
+ ceph_pagelist_encode_8(pagelist, 1);
+ ceph_pagelist_encode_8(pagelist, 1);
+ ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
+ }
+
+ dout(" adding snap realm %llx seq %lld parent %llx\n",
+ realm->ino, realm->seq, realm->parent_ino);
+ sr_rec.ino = cpu_to_le64(realm->ino);
+ sr_rec.seq = cpu_to_le64(realm->seq);
+ sr_rec.parent = cpu_to_le64(realm->parent_ino);
+
+ err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
+ if (err)
+ goto fail;
+
+ recon_state->nr_realms++;
+ }
+fail:
return err;
}
struct ceph_mds_session *session)
{
struct ceph_msg *reply;
- struct rb_node *p;
int mds = session->s_mds;
int err = -ENOMEM;
- int s_nr_caps;
- struct ceph_pagelist *pagelist;
- struct ceph_reconnect_state recon_state;
+ struct ceph_reconnect_state recon_state = {
+ .session = session,
+ };
LIST_HEAD(dispose);
pr_info("mds%d reconnect start\n", mds);
- pagelist = ceph_pagelist_alloc(GFP_NOFS);
- if (!pagelist)
+ recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
+ if (!recon_state.pagelist)
goto fail_nopagelist;
reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
/* replay unsafe requests */
replay_unsafe_requests(mdsc, session);
+ ceph_early_kick_flushing_caps(mdsc, session);
+
down_read(&mdsc->snap_rwsem);
- /* traverse this session's caps */
- s_nr_caps = session->s_nr_caps;
- err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
+ /* placeholder for nr_caps */
+ err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
if (err)
goto fail;
- recon_state.nr_caps = 0;
- recon_state.pagelist = pagelist;
- if (session->s_con.peer_features & CEPH_FEATURE_MDSENC)
+ if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
recon_state.msg_version = 3;
- else
+ recon_state.allow_multi = true;
+ } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
+ recon_state.msg_version = 3;
+ } else {
recon_state.msg_version = 2;
+ }
+ /* trsaverse this session's caps */
err = iterate_session_caps(session, encode_caps_cb, &recon_state);
- if (err < 0)
- goto fail;
spin_lock(&session->s_cap_lock);
session->s_cap_reconnect = 0;
spin_unlock(&session->s_cap_lock);
- /*
- * snaprealms. we provide mds with the ino, seq (version), and
- * parent for all of our realms. If the mds has any newer info,
- * it will tell us.
- */
- for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
- struct ceph_snap_realm *realm =
- rb_entry(p, struct ceph_snap_realm, node);
- struct ceph_mds_snaprealm_reconnect sr_rec;
+ if (err < 0)
+ goto fail;
- dout(" adding snap realm %llx seq %lld parent %llx\n",
- realm->ino, realm->seq, realm->parent_ino);
- sr_rec.ino = cpu_to_le64(realm->ino);
- sr_rec.seq = cpu_to_le64(realm->seq);
- sr_rec.parent = cpu_to_le64(realm->parent_ino);
- err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
- if (err)
- goto fail;
+ /* check if all realms can be encoded into current message */
+ if (mdsc->num_snap_realms) {
+ size_t total_len =
+ recon_state.pagelist->length +
+ mdsc->num_snap_realms *
+ sizeof(struct ceph_mds_snaprealm_reconnect);
+ if (recon_state.msg_version >= 4) {
+ /* number of realms */
+ total_len += sizeof(u32);
+ /* version, compat_version and struct_len */
+ total_len += mdsc->num_snap_realms *
+ (2 * sizeof(u8) + sizeof(u32));
+ }
+ if (total_len > RECONNECT_MAX_SIZE) {
+ if (!recon_state.allow_multi) {
+ err = -ENOSPC;
+ goto fail;
+ }
+ if (recon_state.nr_caps) {
+ err = send_reconnect_partial(&recon_state);
+ if (err)
+ goto fail;
+ }
+ recon_state.msg_version = 5;
+ }
}
- reply->hdr.version = cpu_to_le16(recon_state.msg_version);
+ err = encode_snap_realms(mdsc, &recon_state);
+ if (err < 0)
+ goto fail;
+
+ if (recon_state.msg_version >= 5) {
+ err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
+ if (err < 0)
+ goto fail;
+ }
- /* raced with cap release? */
- if (s_nr_caps != recon_state.nr_caps) {
- struct page *page = list_first_entry(&pagelist->head,
- struct page, lru);
+ if (recon_state.nr_caps || recon_state.nr_realms) {
+ struct page *page =
+ list_first_entry(&recon_state.pagelist->head,
+ struct page, lru);
__le32 *addr = kmap_atomic(page);
- *addr = cpu_to_le32(recon_state.nr_caps);
+ if (recon_state.nr_caps) {
+ WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
+ *addr = cpu_to_le32(recon_state.nr_caps);
+ } else if (recon_state.msg_version >= 4) {
+ *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
+ }
kunmap_atomic(addr);
}
- reply->hdr.data_len = cpu_to_le32(pagelist->length);
- ceph_msg_data_add_pagelist(reply, pagelist);
+ reply->hdr.version = cpu_to_le16(recon_state.msg_version);
+ if (recon_state.msg_version >= 4)
+ reply->hdr.compat_version = cpu_to_le16(4);
- ceph_early_kick_flushing_caps(mdsc, session);
+ reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
+ ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
ceph_con_send(&session->s_con, reply);
mutex_unlock(&mdsc->mutex);
up_read(&mdsc->snap_rwsem);
- ceph_pagelist_release(pagelist);
+ ceph_pagelist_release(recon_state.pagelist);
return;
fail:
up_read(&mdsc->snap_rwsem);
mutex_unlock(&session->s_mutex);
fail_nomsg:
- ceph_pagelist_release(pagelist);
+ ceph_pagelist_release(recon_state.pagelist);
fail_nopagelist:
pr_err("error %d preparing reconnect for mds%d\n", err, mds);
return;
pr_info("mds%d recovery completed\n", s->s_mds);
kick_requests(mdsc, i);
ceph_kick_flushing_caps(mdsc, s);
- wake_up_session_caps(s, 1);
+ wake_up_session_caps(s, RECONNECT);
}
}
dout("mdsc delayed_work\n");
ceph_check_delayed_caps(mdsc);
+ ceph_trim_snapid_map(mdsc);
+
mutex_lock(&mdsc->mutex);
renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
renew_caps = time_after_eq(jiffies, HZ*renew_interval +
init_rwsem(&mdsc->snap_rwsem);
mdsc->snap_realms = RB_ROOT;
INIT_LIST_HEAD(&mdsc->snap_empty);
+ mdsc->num_snap_realms = 0;
spin_lock_init(&mdsc->snap_empty_lock);
mdsc->last_tid = 0;
mdsc->oldest_tid = 0;
ceph_caps_init(mdsc);
ceph_adjust_min_caps(mdsc, fsc->min_caps);
+ spin_lock_init(&mdsc->snapid_map_lock);
+ mdsc->snapid_map_tree = RB_ROOT;
+ INIT_LIST_HEAD(&mdsc->snapid_map_lru);
+
init_rwsem(&mdsc->pool_perm_rwsem);
mdsc->pool_perm_tree = RB_ROOT;
WARN_ON(!list_empty(&mdsc->cap_delay_list));
mutex_unlock(&mdsc->mutex);
+ ceph_cleanup_snapid_map(mdsc);
+
ceph_cleanup_empty_realms(mdsc);
cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */