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07bd10fb98
linux/fs/ceph/mds_client.c
Sage Weil afcdaea3f2 ceph: flush dirty caps via the cap_dirty list 
Previously we were flushing dirty caps by passing an extra flag
when traversing the delayed caps list.  Besides being a bit ugly,
that can also miss caps that are dirty but didn't result in a
cap requeue: notably, mark_caps_dirty().

Separate the flushing into a separate helper, and traverse the
cap_dirty list.

This also brings i_dirty_item in line with i_dirty_caps: we are
on the list IFF caps != 0.  We carry an inode ref IFF
dirty_caps|flushing_caps != 0.

Lose the unused return value from __ceph_mark_caps_dirty().

Signed-off-by: Sage Weil <sage@newdream.net>
2009-10-15 18:14:35 -07:00

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#include "ceph_debug.h"
#include <linux/wait.h>
#include <linux/sched.h>
#include "mds_client.h"
#include "mon_client.h"
#include "super.h"
#include "messenger.h"
#include "decode.h"
/*
* A cluster of MDS (metadata server) daemons is responsible for
* managing the file system namespace (the directory hierarchy and
* inodes) and for coordinating shared access to storage. Metadata is
* partitioning hierarchically across a number of servers, and that
* partition varies over time as the cluster adjusts the distribution
* in order to balance load.
*
* The MDS client is primarily responsible to managing synchronous
* metadata requests for operations like open, unlink, and so forth.
* If there is a MDS failure, we find out about it when we (possibly
* request and) receive a new MDS map, and can resubmit affected
* requests.
*
* For the most part, though, we take advantage of a lossless
* communications channel to the MDS, and do not need to worry about
* timing out or resubmitting requests.
*
* We maintain a stateful "session" with each MDS we interact with.
* Within each session, we sent periodic heartbeat messages to ensure
* any capabilities or leases we have been issues remain valid. If
* the session times out and goes stale, our leases and capabilities
* are no longer valid.
*/
static void __wake_requests(struct ceph_mds_client *mdsc,
struct list_head *head);
const static struct ceph_connection_operations mds_con_ops;
/*
* mds reply parsing
*/
/*
* parse individual inode info
*/
static int parse_reply_info_in(void **p, void *end,
struct ceph_mds_reply_info_in *info)
{
int err = -EIO;
info->in = *p;
*p += sizeof(struct ceph_mds_reply_inode) +
sizeof(*info->in->fragtree.splits) *
le32_to_cpu(info->in->fragtree.nsplits);
ceph_decode_32_safe(p, end, info->symlink_len, bad);
ceph_decode_need(p, end, info->symlink_len, bad);
info->symlink = *p;
*p += info->symlink_len;
ceph_decode_32_safe(p, end, info->xattr_len, bad);
ceph_decode_need(p, end, info->xattr_len, bad);
info->xattr_data = *p;
*p += info->xattr_len;
return 0;
bad:
return err;
}
/*
* parse a normal reply, which may contain a (dir+)dentry and/or a
* target inode.
*/
static int parse_reply_info_trace(void **p, void *end,
struct ceph_mds_reply_info_parsed *info)
{
int err;
if (info->head->is_dentry) {
err = parse_reply_info_in(p, end, &info->diri);
if (err < 0)
goto out_bad;
if (unlikely(*p + sizeof(*info->dirfrag) > end))
goto bad;
info->dirfrag = *p;
*p += sizeof(*info->dirfrag) +
sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
if (unlikely(*p > end))
goto bad;
ceph_decode_32_safe(p, end, info->dname_len, bad);
ceph_decode_need(p, end, info->dname_len, bad);
info->dname = *p;
*p += info->dname_len;
info->dlease = *p;
*p += sizeof(*info->dlease);
}
if (info->head->is_target) {
err = parse_reply_info_in(p, end, &info->targeti);
if (err < 0)
goto out_bad;
}
if (unlikely(*p != end))
goto bad;
return 0;
bad:
err = -EIO;
out_bad:
pr_err("problem parsing mds trace %d\n", err);
return err;
}
/*
* parse readdir results
*/
static int parse_reply_info_dir(void **p, void *end,
struct ceph_mds_reply_info_parsed *info)
{
u32 num, i = 0;
int err;
info->dir_dir = *p;
if (*p + sizeof(*info->dir_dir) > end)
goto bad;
*p += sizeof(*info->dir_dir) +
sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
if (*p > end)
goto bad;
ceph_decode_need(p, end, sizeof(num) + 2, bad);
num = ceph_decode_32(p);
info->dir_end = ceph_decode_8(p);
info->dir_complete = ceph_decode_8(p);
if (num == 0)
goto done;
/* alloc large array */
info->dir_nr = num;
info->dir_in = kcalloc(num, sizeof(*info->dir_in) +
sizeof(*info->dir_dname) +
sizeof(*info->dir_dname_len) +
sizeof(*info->dir_dlease),
GFP_NOFS);
if (info->dir_in == NULL) {
err = -ENOMEM;
goto out_bad;
}
info->dir_dname = (void *)(info->dir_in + num);
info->dir_dname_len = (void *)(info->dir_dname + num);
info->dir_dlease = (void *)(info->dir_dname_len + num);
while (num) {
/* dentry */
ceph_decode_need(p, end, sizeof(u32)*2, bad);
info->dir_dname_len[i] = ceph_decode_32(p);
ceph_decode_need(p, end, info->dir_dname_len[i], bad);
info->dir_dname[i] = *p;
*p += info->dir_dname_len[i];
dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i],
info->dir_dname[i]);
info->dir_dlease[i] = *p;
*p += sizeof(struct ceph_mds_reply_lease);
/* inode */
err = parse_reply_info_in(p, end, &info->dir_in[i]);
if (err < 0)
goto out_bad;
i++;
num--;
}
done:
if (*p != end)
goto bad;
return 0;
bad:
err = -EIO;
out_bad:
pr_err("problem parsing dir contents %d\n", err);
return err;
}
/*
* parse entire mds reply
*/
static int parse_reply_info(struct ceph_msg *msg,
struct ceph_mds_reply_info_parsed *info)
{
void *p, *end;
u32 len;
int err;
info->head = msg->front.iov_base;
p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
/* trace */
ceph_decode_32_safe(&p, end, len, bad);
if (len > 0) {
err = parse_reply_info_trace(&p, p+len, info);
if (err < 0)
goto out_bad;
}
/* dir content */
ceph_decode_32_safe(&p, end, len, bad);
if (len > 0) {
err = parse_reply_info_dir(&p, p+len, info);
if (err < 0)
goto out_bad;
}
/* snap blob */
ceph_decode_32_safe(&p, end, len, bad);
info->snapblob_len = len;
info->snapblob = p;
p += len;
if (p != end)
goto bad;
return 0;
bad:
err = -EIO;
out_bad:
pr_err("mds parse_reply err %d\n", err);
return err;
}
static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
{
kfree(info->dir_in);
}
/*
* sessions
*/
static const char *session_state_name(int s)
{
switch (s) {
case CEPH_MDS_SESSION_NEW: return "new";
case CEPH_MDS_SESSION_OPENING: return "opening";
case CEPH_MDS_SESSION_OPEN: return "open";
case CEPH_MDS_SESSION_HUNG: return "hung";
case CEPH_MDS_SESSION_CLOSING: return "closing";
case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
default: return "???";
}
}
static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
{
if (atomic_inc_not_zero(&s->s_ref)) {
dout("mdsc get_session %p %d -> %d\n", s,
atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
return s;
} else {
dout("mdsc get_session %p 0 -- FAIL", s);
return NULL;
}
}
void ceph_put_mds_session(struct ceph_mds_session *s)
{
dout("mdsc put_session %p %d -> %d\n", s,
atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
if (atomic_dec_and_test(&s->s_ref)) {
ceph_con_shutdown(&s->s_con);
kfree(s);
}
}
/*
* called under mdsc->mutex
*/
struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
int mds)
{
struct ceph_mds_session *session;
if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
return NULL;
session = mdsc->sessions[mds];
dout("lookup_mds_session %p %d\n", session,
atomic_read(&session->s_ref));
get_session(session);
return session;
}
static bool __have_session(struct ceph_mds_client *mdsc, int mds)
{
if (mds >= mdsc->max_sessions)
return false;
return mdsc->sessions[mds];
}
/*
* create+register a new session for given mds.
* called under mdsc->mutex.
*/
static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
int mds)
{
struct ceph_mds_session *s;
s = kzalloc(sizeof(*s), GFP_NOFS);
s->s_mdsc = mdsc;
s->s_mds = mds;
s->s_state = CEPH_MDS_SESSION_NEW;
s->s_ttl = 0;
s->s_seq = 0;
mutex_init(&s->s_mutex);
ceph_con_init(mdsc->client->msgr, &s->s_con);
s->s_con.private = s;
s->s_con.ops = &mds_con_ops;
s->s_con.peer_name.type = CEPH_ENTITY_TYPE_MDS;
s->s_con.peer_name.num = cpu_to_le64(mds);
ceph_con_open(&s->s_con, ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
spin_lock_init(&s->s_cap_lock);
s->s_cap_gen = 0;
s->s_cap_ttl = 0;
s->s_renew_requested = 0;
s->s_renew_seq = 0;
INIT_LIST_HEAD(&s->s_caps);
s->s_nr_caps = 0;
atomic_set(&s->s_ref, 1);
INIT_LIST_HEAD(&s->s_waiting);
INIT_LIST_HEAD(&s->s_unsafe);
s->s_num_cap_releases = 0;
INIT_LIST_HEAD(&s->s_cap_releases);
INIT_LIST_HEAD(&s->s_cap_releases_done);
INIT_LIST_HEAD(&s->s_cap_flushing);
INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
dout("register_session mds%d\n", mds);
if (mds >= mdsc->max_sessions) {
int newmax = 1 << get_count_order(mds+1);
struct ceph_mds_session **sa;
dout("register_session realloc to %d\n", newmax);
sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
if (sa == NULL)
return ERR_PTR(-ENOMEM);
if (mdsc->sessions) {
memcpy(sa, mdsc->sessions,
mdsc->max_sessions * sizeof(void *));
kfree(mdsc->sessions);
}
mdsc->sessions = sa;
mdsc->max_sessions = newmax;
}
mdsc->sessions[mds] = s;
atomic_inc(&s->s_ref); /* one ref to sessions[], one to caller */
return s;
}
/*
* called under mdsc->mutex
*/
static void unregister_session(struct ceph_mds_client *mdsc, int mds)
{
dout("unregister_session mds%d %p\n", mds, mdsc->sessions[mds]);
ceph_put_mds_session(mdsc->sessions[mds]);
mdsc->sessions[mds] = NULL;
}
/*
* drop session refs in request.
*
* should be last request ref, or hold mdsc->mutex
*/
static void put_request_session(struct ceph_mds_request *req)
{
if (req->r_session) {
ceph_put_mds_session(req->r_session);
req->r_session = NULL;
}
}
void ceph_mdsc_put_request(struct ceph_mds_request *req)
{
dout("mdsc put_request %p %d -> %d\n", req,
atomic_read(&req->r_ref), atomic_read(&req->r_ref)-1);
if (atomic_dec_and_test(&req->r_ref)) {
if (req->r_request)
ceph_msg_put(req->r_request);
if (req->r_reply) {
ceph_msg_put(req->r_reply);
destroy_reply_info(&req->r_reply_info);
}
if (req->r_inode) {
ceph_put_cap_refs(ceph_inode(req->r_inode),
CEPH_CAP_PIN);
iput(req->r_inode);
}
if (req->r_locked_dir)
ceph_put_cap_refs(ceph_inode(req->r_locked_dir),
CEPH_CAP_PIN);
if (req->r_target_inode)
iput(req->r_target_inode);
if (req->r_dentry)
dput(req->r_dentry);
if (req->r_old_dentry) {
ceph_put_cap_refs(
ceph_inode(req->r_old_dentry->d_parent->d_inode),
CEPH_CAP_PIN);
dput(req->r_old_dentry);
}
kfree(req->r_path1);
kfree(req->r_path2);
put_request_session(req);
ceph_unreserve_caps(&req->r_caps_reservation);
kfree(req);
}
}
/*
* lookup session, bump ref if found.
*
* called under mdsc->mutex.
*/
static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc,
u64 tid)
{
struct ceph_mds_request *req;
req = radix_tree_lookup(&mdsc->request_tree, tid);
if (req)
ceph_mdsc_get_request(req);
return req;
}
/*
* Register an in-flight request, and assign a tid. Link to directory
* are modifying (if any).
*
* Called under mdsc->mutex.
*/
static void __register_request(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req,
struct inode *dir)
{
req->r_tid = ++mdsc->last_tid;
if (req->r_num_caps)
ceph_reserve_caps(&req->r_caps_reservation, req->r_num_caps);
dout("__register_request %p tid %lld\n", req, req->r_tid);
ceph_mdsc_get_request(req);
radix_tree_insert(&mdsc->request_tree, req->r_tid, (void *)req);
if (dir) {
struct ceph_inode_info *ci = ceph_inode(dir);
spin_lock(&ci->i_unsafe_lock);
req->r_unsafe_dir = dir;
list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
spin_unlock(&ci->i_unsafe_lock);
}
}
static void __unregister_request(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req)
{
dout("__unregister_request %p tid %lld\n", req, req->r_tid);
radix_tree_delete(&mdsc->request_tree, req->r_tid);
ceph_mdsc_put_request(req);
if (req->r_unsafe_dir) {
struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
spin_lock(&ci->i_unsafe_lock);
list_del_init(&req->r_unsafe_dir_item);
spin_unlock(&ci->i_unsafe_lock);
}
}
/*
* Choose mds to send request to next. If there is a hint set in the
* request (e.g., due to a prior forward hint from the mds), use that.
* Otherwise, consult frag tree and/or caps to identify the
* appropriate mds. If all else fails, choose randomly.
*
* Called under mdsc->mutex.
*/
static int __choose_mds(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req)
{
struct inode *inode;
struct ceph_inode_info *ci;
struct ceph_cap *cap;
int mode = req->r_direct_mode;
int mds = -1;
u32 hash = req->r_direct_hash;
bool is_hash = req->r_direct_is_hash;
/*
* is there a specific mds we should try? ignore hint if we have
* no session and the mds is not up (active or recovering).
*/
if (req->r_resend_mds >= 0 &&
(__have_session(mdsc, req->r_resend_mds) ||
ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
dout("choose_mds using resend_mds mds%d\n",
req->r_resend_mds);
return req->r_resend_mds;
}
if (mode == USE_RANDOM_MDS)
goto random;
inode = NULL;
if (req->r_inode) {
inode = req->r_inode;
} else if (req->r_dentry) {
if (req->r_dentry->d_inode) {
inode = req->r_dentry->d_inode;
} else {
inode = req->r_dentry->d_parent->d_inode;
hash = req->r_dentry->d_name.hash;
is_hash = true;
}
}
dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
(int)hash, mode);
if (!inode)
goto random;
ci = ceph_inode(inode);
if (is_hash && S_ISDIR(inode->i_mode)) {
struct ceph_inode_frag frag;
int found;
ceph_choose_frag(ci, hash, &frag, &found);
if (found) {
if (mode == USE_ANY_MDS && frag.ndist > 0) {
u8 r;
/* choose a random replica */
get_random_bytes(&r, 1);
r %= frag.ndist;
mds = frag.dist[r];
dout("choose_mds %p %llx.%llx "
"frag %u mds%d (%d/%d)\n",
inode, ceph_vinop(inode),
frag.frag, frag.mds,
(int)r, frag.ndist);
return mds;
}
/* since this file/dir wasn't known to be
* replicated, then we want to look for the
* authoritative mds. */
mode = USE_AUTH_MDS;
if (frag.mds >= 0) {
/* choose auth mds */
mds = frag.mds;
dout("choose_mds %p %llx.%llx "
"frag %u mds%d (auth)\n",
inode, ceph_vinop(inode), frag.frag, mds);
return mds;
}
}
}
spin_lock(&inode->i_lock);
cap = NULL;
if (mode == USE_AUTH_MDS)
cap = ci->i_auth_cap;
if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
if (!cap) {
spin_unlock(&inode->i_lock);
goto random;
}
mds = cap->session->s_mds;
dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
inode, ceph_vinop(inode), mds,
cap == ci->i_auth_cap ? "auth " : "", cap);
spin_unlock(&inode->i_lock);
return mds;
random:
mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
dout("choose_mds chose random mds%d\n", mds);
return mds;
}
/*
* session messages
*/
static struct ceph_msg *create_session_msg(u32 op, u64 seq)
{
struct ceph_msg *msg;
struct ceph_mds_session_head *h;
msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), 0, 0, NULL);
if (IS_ERR(msg)) {
pr_err("create_session_msg ENOMEM creating msg\n");
return ERR_PTR(PTR_ERR(msg));
}
h = msg->front.iov_base;
h->op = cpu_to_le32(op);
h->seq = cpu_to_le64(seq);
return msg;
}
/*
* send session open request.
*
* called under mdsc->mutex
*/
static int __open_session(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_msg *msg;
int mstate;
int mds = session->s_mds;
int err = 0;
/* wait for mds to go active? */
mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
dout("open_session to mds%d (%s)\n", mds,
ceph_mds_state_name(mstate));
session->s_state = CEPH_MDS_SESSION_OPENING;
session->s_renew_requested = jiffies;
/* send connect message */
msg = create_session_msg(CEPH_SESSION_REQUEST_OPEN, session->s_seq);
if (IS_ERR(msg)) {
err = PTR_ERR(msg);
goto out;
}
ceph_con_send(&session->s_con, msg);
out:
return 0;
}
/*
* session caps
*/
/*
* Free preallocated cap messages assigned to this session
*/
static void cleanup_cap_releases(struct ceph_mds_session *session)
{
struct ceph_msg *msg;
spin_lock(&session->s_cap_lock);
while (!list_empty(&session->s_cap_releases)) {
msg = list_first_entry(&session->s_cap_releases,
struct ceph_msg, list_head);
list_del_init(&msg->list_head);
ceph_msg_put(msg);
}
while (!list_empty(&session->s_cap_releases_done)) {
msg = list_first_entry(&session->s_cap_releases_done,
struct ceph_msg, list_head);
list_del_init(&msg->list_head);
ceph_msg_put(msg);
}
spin_unlock(&session->s_cap_lock);
}
/*
* Helper to safely iterate over all caps associated with a session.
*
* caller must hold session s_mutex
*/
static int iterate_session_caps(struct ceph_mds_session *session,
int (*cb)(struct inode *, struct ceph_cap *,
void *), void *arg)
{
struct ceph_cap *cap, *ncap;
struct inode *inode;
int ret;
dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
spin_lock(&session->s_cap_lock);
list_for_each_entry_safe(cap, ncap, &session->s_caps, session_caps) {
inode = igrab(&cap->ci->vfs_inode);
if (!inode)
continue;
spin_unlock(&session->s_cap_lock);
ret = cb(inode, cap, arg);
iput(inode);
if (ret < 0)
return ret;
spin_lock(&session->s_cap_lock);
}
spin_unlock(&session->s_cap_lock);
return 0;
}
static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
void *arg)
{
struct ceph_inode_info *ci = ceph_inode(inode);
dout("removing cap %p, ci is %p, inode is %p\n",
cap, ci, &ci->vfs_inode);
ceph_remove_cap(cap);
return 0;
}
/*
* caller must hold session s_mutex
*/
static void remove_session_caps(struct ceph_mds_session *session)
{
dout("remove_session_caps on %p\n", session);
iterate_session_caps(session, remove_session_caps_cb, NULL);
BUG_ON(session->s_nr_caps > 0);
cleanup_cap_releases(session);
}
/*
* 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.
*
* caller must hold s_mutex.
*/
static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
void *arg)
{
struct ceph_mds_session *session = arg;
spin_lock(&inode->i_lock);
if (cap->gen != session->s_cap_gen) {
pr_err("failed reconnect %p %llx.%llx cap %p "
"(gen %d < session %d)\n", inode, ceph_vinop(inode),
cap, cap->gen, session->s_cap_gen);
__ceph_remove_cap(cap, NULL);
}
wake_up(&ceph_inode(inode)->i_cap_wq);
spin_unlock(&inode->i_lock);
return 0;
}
static void wake_up_session_caps(struct ceph_mds_session *session)
{
dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
iterate_session_caps(session, wake_up_session_cb, session);
}
/*
* Send periodic message to MDS renewing all currently held caps. The
* ack will reset the expiration for all caps from this session.
*
* caller holds s_mutex
*/
static int send_renew_caps(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_msg *msg;
int state;
if (time_after_eq(jiffies, session->s_cap_ttl) &&
time_after_eq(session->s_cap_ttl, session->s_renew_requested))
pr_info("mds%d caps stale\n", session->s_mds);
/* do not try to renew caps until a recovering mds has reconnected
* with its clients. */
state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
if (state < CEPH_MDS_STATE_RECONNECT) {
dout("send_renew_caps ignoring mds%d (%s)\n",
session->s_mds, ceph_mds_state_name(state));
return 0;
}
dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
ceph_mds_state_name(state));
session->s_renew_requested = jiffies;
msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
++session->s_renew_seq);
if (IS_ERR(msg))
return PTR_ERR(msg);
ceph_con_send(&session->s_con, msg);
return 0;
}
/*
* Note new cap ttl, and any transition from stale -> not stale (fresh?).
*/
static void renewed_caps(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session, int is_renew)
{
int was_stale;
int wake = 0;
spin_lock(&session->s_cap_lock);
was_stale = is_renew && (session->s_cap_ttl == 0 ||
time_after_eq(jiffies, session->s_cap_ttl));
session->s_cap_ttl = session->s_renew_requested +
mdsc->mdsmap->m_session_timeout*HZ;
if (was_stale) {
if (time_before(jiffies, session->s_cap_ttl)) {
pr_info("mds%d caps renewed\n", session->s_mds);
wake = 1;
} else {
pr_info("mds%d caps still stale\n", session->s_mds);
}
}
dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
spin_unlock(&session->s_cap_lock);
if (wake)
wake_up_session_caps(session);
}
/*
* send a session close request
*/
static int request_close_session(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_msg *msg;
int err = 0;
dout("request_close_session mds%d state %s seq %lld\n",
session->s_mds, session_state_name(session->s_state),
session->s_seq);
msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
if (IS_ERR(msg))
err = PTR_ERR(msg);
else
ceph_con_send(&session->s_con, msg);
return err;
}
/*
* Called with s_mutex held.
*/
static int __close_session(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
return 0;
session->s_state = CEPH_MDS_SESSION_CLOSING;
return request_close_session(mdsc, session);
}
/*
* Trim old(er) caps.
*
* Because we can't cache an inode without one or more caps, we do
* this indirectly: if a cap is unused, we prune its aliases, at which
* point the inode will hopefully get dropped to.
*
* Yes, this is a bit sloppy. Our only real goal here is to respond to
* memory pressure from the MDS, though, so it needn't be perfect.
*/
static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
{
struct ceph_mds_session *session = arg;
struct ceph_inode_info *ci = ceph_inode(inode);
int used, oissued, mine;
if (session->s_trim_caps <= 0)
return -1;
spin_lock(&inode->i_lock);
mine = cap->issued | cap->implemented;
used = __ceph_caps_used(ci);
oissued = __ceph_caps_issued_other(ci, cap);
dout("trim_caps_cb %p cap %p mine %s oissued %s used %s\n",
inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
ceph_cap_string(used));
if (ci->i_dirty_caps)
goto out; /* dirty caps */
if ((used & ~oissued) & mine)
goto out; /* we need these caps */
session->s_trim_caps--;
if (oissued) {
/* we aren't the only cap.. just remove us */
__ceph_remove_cap(cap, NULL);
} else {
/* try to drop referring dentries */
spin_unlock(&inode->i_lock);
d_prune_aliases(inode);
dout("trim_caps_cb %p cap %p pruned, count now %d\n",
inode, cap, atomic_read(&inode->i_count));
return 0;
}
out:
spin_unlock(&inode->i_lock);
return 0;
}
/*
* Trim session cap count down to some max number.
*/
static int trim_caps(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session,
int max_caps)
{
int trim_caps = session->s_nr_caps - max_caps;
dout("trim_caps mds%d start: %d / %d, trim %d\n",
session->s_mds, session->s_nr_caps, max_caps, trim_caps);
if (trim_caps > 0) {
session->s_trim_caps = trim_caps;
iterate_session_caps(session, trim_caps_cb, session);
dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
session->s_mds, session->s_nr_caps, max_caps,
trim_caps - session->s_trim_caps);
}
return 0;
}
/*
* Allocate cap_release messages. If there is a partially full message
* in the queue, try to allocate enough to cover it's remainder, so that
* we can send it immediately.
*
* Called under s_mutex.
*/
static int add_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session,
int extra)
{
struct ceph_msg *msg;
struct ceph_mds_cap_release *head;
int err = -ENOMEM;
if (extra < 0)
extra = mdsc->client->mount_args.cap_release_safety;
spin_lock(&session->s_cap_lock);
if (!list_empty(&session->s_cap_releases)) {
msg = list_first_entry(&session->s_cap_releases,
struct ceph_msg,
list_head);
head = msg->front.iov_base;
extra += CEPH_CAPS_PER_RELEASE - le32_to_cpu(head->num);
}
while (session->s_num_cap_releases < session->s_nr_caps + extra) {
spin_unlock(&session->s_cap_lock);
msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE,
0, 0, NULL);
if (!msg)
goto out_unlocked;
dout("add_cap_releases %p msg %p now %d\n", session, msg,
(int)msg->front.iov_len);
head = msg->front.iov_base;
head->num = cpu_to_le32(0);
msg->front.iov_len = sizeof(*head);
spin_lock(&session->s_cap_lock);
list_add(&msg->list_head, &session->s_cap_releases);
session->s_num_cap_releases += CEPH_CAPS_PER_RELEASE;
}
if (!list_empty(&session->s_cap_releases)) {
msg = list_first_entry(&session->s_cap_releases,
struct ceph_msg,
list_head);
head = msg->front.iov_base;
if (head->num) {
dout(" queueing non-full %p (%d)\n", msg,
le32_to_cpu(head->num));
list_move_tail(&msg->list_head,
&session->s_cap_releases_done);
session->s_num_cap_releases -=
CEPH_CAPS_PER_RELEASE - le32_to_cpu(head->num);
}
}
err = 0;
spin_unlock(&session->s_cap_lock);
out_unlocked:
return err;
}
/*
* flush all dirty inode data to disk.
*
* returns true if we've flushed through want_flush_seq
*/
static int check_cap_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq)
{
int mds, ret = 1;
dout("check_cap_flush want %lld\n", want_flush_seq);
mutex_lock(&mdsc->mutex);
for (mds = 0; ret && mds < mdsc->max_sessions; mds++) {
struct ceph_mds_session *session = mdsc->sessions[mds];
if (!session)
continue;
get_session(session);
mutex_unlock(&mdsc->mutex);
mutex_lock(&session->s_mutex);
if (!list_empty(&session->s_cap_flushing)) {
struct ceph_inode_info *ci =
list_entry(session->s_cap_flushing.next,
struct ceph_inode_info,
i_flushing_item);
struct inode *inode = &ci->vfs_inode;
spin_lock(&inode->i_lock);
if (ci->i_cap_flush_seq <= want_flush_seq) {
dout("check_cap_flush still flushing %p "
"seq %lld <= %lld to mds%d\n", inode,
ci->i_cap_flush_seq, want_flush_seq,
session->s_mds);
ret = 0;
}
spin_unlock(&inode->i_lock);
}
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
if (!ret)
return ret;
mutex_lock(&mdsc->mutex);
}
mutex_unlock(&mdsc->mutex);
dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
return ret;
}
/*
* called under s_mutex
*/
static void send_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_msg *msg;
dout("send_cap_releases mds%d\n", session->s_mds);
while (1) {
spin_lock(&session->s_cap_lock);
if (list_empty(&session->s_cap_releases_done))
break;
msg = list_first_entry(&session->s_cap_releases_done,
struct ceph_msg, list_head);
list_del_init(&msg->list_head);
spin_unlock(&session->s_cap_lock);
msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
ceph_con_send(&session->s_con, msg);
}
spin_unlock(&session->s_cap_lock);
}
/*
* requests
*/
/*
* Create an mds request.
*/
struct ceph_mds_request *
ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
{
struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
if (!req)
return ERR_PTR(-ENOMEM);
req->r_started = jiffies;
req->r_resend_mds = -1;
INIT_LIST_HEAD(&req->r_unsafe_dir_item);
req->r_fmode = -1;
atomic_set(&req->r_ref, 1); /* one for request_tree, one for caller */
INIT_LIST_HEAD(&req->r_wait);
init_completion(&req->r_completion);
init_completion(&req->r_safe_completion);
INIT_LIST_HEAD(&req->r_unsafe_item);
req->r_op = op;
req->r_direct_mode = mode;
return req;
}
/*
* return oldest (lowest) tid in request tree, 0 if none.
*
* called under mdsc->mutex.
*/
static u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
{
struct ceph_mds_request *first;
if (radix_tree_gang_lookup(&mdsc->request_tree,
(void **)&first, 0, 1) <= 0)
return 0;
return first->r_tid;
}
/*
* Build a dentry's path. Allocate on heap; caller must kfree. Based
* on build_path_from_dentry in fs/cifs/dir.c.
*
* If @stop_on_nosnap, generate path relative to the first non-snapped
* inode.
*
* Encode hidden .snap dirs as a double /, i.e.
* foo/.snap/bar -> foo//bar
*/
char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
int stop_on_nosnap)
{
struct dentry *temp;
char *path;
int len, pos;
if (dentry == NULL)
return ERR_PTR(-EINVAL);
retry:
len = 0;
for (temp = dentry; !IS_ROOT(temp);) {
struct inode *inode = temp->d_inode;
if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
len++; /* slash only */
else if (stop_on_nosnap && inode &&
ceph_snap(inode) == CEPH_NOSNAP)
break;
else
len += 1 + temp->d_name.len;
temp = temp->d_parent;
if (temp == NULL) {
pr_err("build_path_dentry corrupt dentry %p\n", dentry);
return ERR_PTR(-EINVAL);
}
}
if (len)
len--; /* no leading '/' */
path = kmalloc(len+1, GFP_NOFS);
if (path == NULL)
return ERR_PTR(-ENOMEM);
pos = len;
path[pos] = 0; /* trailing null */
for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
struct inode *inode = temp->d_inode;
if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
dout("build_path_dentry path+%d: %p SNAPDIR\n",
pos, temp);
} else if (stop_on_nosnap && inode &&
ceph_snap(inode) == CEPH_NOSNAP) {
break;
} else {
pos -= temp->d_name.len;
if (pos < 0)
break;
strncpy(path + pos, temp->d_name.name,
temp->d_name.len);
dout("build_path_dentry path+%d: %p '%.*s'\n",
pos, temp, temp->d_name.len, path + pos);
}
if (pos)
path[--pos] = '/';
temp = temp->d_parent;
if (temp == NULL) {
pr_err("build_path_dentry corrupt dentry\n");
kfree(path);
return ERR_PTR(-EINVAL);
}
}
if (pos != 0) {
pr_err("build_path_dentry did not end path lookup where "
"expected, namelen is %d, pos is %d\n", len, pos);
/* presumably this is only possible if racing with a
rename of one of the parent directories (we can not
lock the dentries above us to prevent this, but
retrying should be harmless) */
kfree(path);
goto retry;
}
*base = ceph_ino(temp->d_inode);
*plen = len;
dout("build_path_dentry on %p %d built %llx '%.*s'\n",
dentry, atomic_read(&dentry->d_count), *base, len, path);
return path;
}
static int build_dentry_path(struct dentry *dentry,
const char **ppath, int *ppathlen, u64 *pino,
int *pfreepath)
{
char *path;
if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP) {
*pino = ceph_ino(dentry->d_parent->d_inode);
*ppath = dentry->d_name.name;
*ppathlen = dentry->d_name.len;
return 0;
}
path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
if (IS_ERR(path))
return PTR_ERR(path);
*ppath = path;
*pfreepath = 1;
return 0;
}
static int build_inode_path(struct inode *inode,
const char **ppath, int *ppathlen, u64 *pino,
int *pfreepath)
{
struct dentry *dentry;
char *path;
if (ceph_snap(inode) == CEPH_NOSNAP) {
*pino = ceph_ino(inode);
*ppathlen = 0;
return 0;
}
dentry = d_find_alias(inode);
path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
dput(dentry);
if (IS_ERR(path))
return PTR_ERR(path);
*ppath = path;
*pfreepath = 1;
return 0;
}
/*
* request arguments may be specified via an inode *, a dentry *, or
* an explicit ino+path.
*/
static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
const char *rpath, u64 rino,
const char **ppath, int *pathlen,
u64 *ino, int *freepath)
{
int r = 0;
if (rinode) {
r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
ceph_snap(rinode));
} else if (rdentry) {
r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
*ppath);
} else if (rpath) {
*ino = rino;
*ppath = rpath;
*pathlen = strlen(rpath);
dout(" path %.*s\n", *pathlen, rpath);
}
return r;
}
/*
* called under mdsc->mutex
*/
static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req,
int mds)
{
struct ceph_msg *msg;
struct ceph_mds_request_head *head;
const char *path1 = NULL;
const char *path2 = NULL;
u64 ino1 = 0, ino2 = 0;
int pathlen1 = 0, pathlen2 = 0;
int freepath1 = 0, freepath2 = 0;
int len;
u16 releases;
void *p, *end;
int ret;
ret = set_request_path_attr(req->r_inode, req->r_dentry,
req->r_path1, req->r_ino1.ino,
&path1, &pathlen1, &ino1, &freepath1);
if (ret < 0) {
msg = ERR_PTR(ret);
goto out;
}
ret = set_request_path_attr(NULL, req->r_old_dentry,
req->r_path2, req->r_ino2.ino,
&path2, &pathlen2, &ino2, &freepath2);
if (ret < 0) {
msg = ERR_PTR(ret);
goto out_free1;
}
len = sizeof(*head) +
pathlen1 + pathlen2 + 2*(sizeof(u32) + sizeof(u64));
/* calculate (max) length for cap releases */
len += sizeof(struct ceph_mds_request_release) *
(!!req->r_inode_drop + !!req->r_dentry_drop +
!!req->r_old_inode_drop + !!req->r_old_dentry_drop);
if (req->r_dentry_drop)
len += req->r_dentry->d_name.len;
if (req->r_old_dentry_drop)
len += req->r_old_dentry->d_name.len;
msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, 0, 0, NULL);
if (IS_ERR(msg))
goto out_free2;
head = msg->front.iov_base;
p = msg->front.iov_base + sizeof(*head);
end = msg->front.iov_base + msg->front.iov_len;
head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
head->op = cpu_to_le32(req->r_op);
head->caller_uid = cpu_to_le32(current_fsuid());
head->caller_gid = cpu_to_le32(current_fsgid());
head->args = req->r_args;
ceph_encode_filepath(&p, end, ino1, path1);
ceph_encode_filepath(&p, end, ino2, path2);
/* cap releases */
releases = 0;
if (req->r_inode_drop)
releases += ceph_encode_inode_release(&p,
req->r_inode ? req->r_inode : req->r_dentry->d_inode,
mds, req->r_inode_drop, req->r_inode_unless, 0);
if (req->r_dentry_drop)
releases += ceph_encode_dentry_release(&p, req->r_dentry,
mds, req->r_dentry_drop, req->r_dentry_unless);
if (req->r_old_dentry_drop)
releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
if (req->r_old_inode_drop)
releases += ceph_encode_inode_release(&p,
req->r_old_dentry->d_inode,
mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
head->num_releases = cpu_to_le16(releases);
BUG_ON(p > end);
msg->front.iov_len = p - msg->front.iov_base;
msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
msg->pages = req->r_pages;
msg->nr_pages = req->r_num_pages;
msg->hdr.data_len = cpu_to_le32(req->r_data_len);
msg->hdr.data_off = cpu_to_le16(0);
out_free2:
if (freepath2)
kfree((char *)path2);
out_free1:
if (freepath1)
kfree((char *)path1);
out:
return msg;
}
/*
* called under mdsc->mutex if error, under no mutex if
* success.
*/
static void complete_request(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req)
{
if (req->r_callback)
req->r_callback(mdsc, req);
else
complete(&req->r_completion);
}
/*
* called under mdsc->mutex
*/
static int __prepare_send_request(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req,
int mds)
{
struct ceph_mds_request_head *rhead;
struct ceph_msg *msg;
int flags = 0;
req->r_mds = mds;
req->r_attempts++;
dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
if (req->r_request) {
ceph_msg_put(req->r_request);
req->r_request = NULL;
}
msg = create_request_message(mdsc, req, mds);
if (IS_ERR(msg)) {
req->r_reply = ERR_PTR(PTR_ERR(msg));
complete_request(mdsc, req);
return -PTR_ERR(msg);
}
req->r_request = msg;
rhead = msg->front.iov_base;
rhead->tid = cpu_to_le64(req->r_tid);
rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
if (req->r_got_unsafe)
flags |= CEPH_MDS_FLAG_REPLAY;
if (req->r_locked_dir)
flags |= CEPH_MDS_FLAG_WANT_DENTRY;
rhead->flags = cpu_to_le32(flags);
rhead->num_fwd = req->r_num_fwd;
rhead->num_retry = req->r_attempts - 1;
dout(" r_locked_dir = %p\n", req->r_locked_dir);
if (req->r_target_inode && req->r_got_unsafe)
rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
else
rhead->ino = 0;
return 0;
}
/*
* send request, or put it on the appropriate wait list.
*/
static int __do_request(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req)
{
struct ceph_mds_session *session = NULL;
int mds = -1;
int err = -EAGAIN;
if (req->r_reply)
goto out;
if (req->r_timeout &&
time_after_eq(jiffies, req->r_started + req->r_timeout)) {
dout("do_request timed out\n");
err = -EIO;
goto finish;
}
mds = __choose_mds(mdsc, req);
if (mds < 0 ||
ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
dout("do_request no mds or not active, waiting for map\n");
list_add(&req->r_wait, &mdsc->waiting_for_map);
goto out;
}
/* get, open session */
session = __ceph_lookup_mds_session(mdsc, mds);
if (!session)
session = register_session(mdsc, mds);
dout("do_request mds%d session %p state %s\n", mds, session,
session_state_name(session->s_state));
if (session->s_state != CEPH_MDS_SESSION_OPEN &&
session->s_state != CEPH_MDS_SESSION_HUNG) {
if (session->s_state == CEPH_MDS_SESSION_NEW ||
session->s_state == CEPH_MDS_SESSION_CLOSING)
__open_session(mdsc, session);
list_add(&req->r_wait, &session->s_waiting);
goto out_session;
}
/* send request */
req->r_session = get_session(session);
req->r_resend_mds = -1; /* forget any previous mds hint */
if (req->r_request_started == 0) /* note request start time */
req->r_request_started = jiffies;
err = __prepare_send_request(mdsc, req, mds);
if (!err) {
ceph_msg_get(req->r_request);
ceph_con_send(&session->s_con, req->r_request);
}
out_session:
ceph_put_mds_session(session);
out:
return err;
finish:
req->r_reply = ERR_PTR(err);
complete_request(mdsc, req);
goto out;
}
/*
* called under mdsc->mutex
*/
static void __wake_requests(struct ceph_mds_client *mdsc,
struct list_head *head)
{
struct ceph_mds_request *req, *nreq;
list_for_each_entry_safe(req, nreq, head, r_wait) {
list_del_init(&req->r_wait);
__do_request(mdsc, req);
}
}
/*
* Wake up threads with requests pending for @mds, so that they can
* resubmit their requests to a possibly different mds. If @all is set,
* wake up if their requests has been forwarded to @mds, too.
*/
static void kick_requests(struct ceph_mds_client *mdsc, int mds, int all)
{
struct ceph_mds_request *reqs[10];
u64 nexttid = 0;
int i, got;
dout("kick_requests mds%d\n", mds);
while (nexttid <= mdsc->last_tid) {
got = radix_tree_gang_lookup(&mdsc->request_tree,
(void **)&reqs, nexttid, 10);
if (got == 0)
break;
nexttid = reqs[got-1]->r_tid + 1;
for (i = 0; i < got; i++) {
if (reqs[i]->r_got_unsafe)
continue;
if (reqs[i]->r_session &&
reqs[i]->r_session->s_mds == mds) {
dout(" kicking tid %llu\n", reqs[i]->r_tid);
put_request_session(reqs[i]);
__do_request(mdsc, reqs[i]);
}
}
}
}
void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req)
{
dout("submit_request on %p\n", req);
mutex_lock(&mdsc->mutex);
__register_request(mdsc, req, NULL);
__do_request(mdsc, req);
mutex_unlock(&mdsc->mutex);
}
/*
* Synchrously perform an mds request. Take care of all of the
* session setup, forwarding, retry details.
*/
int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
struct inode *dir,
struct ceph_mds_request *req)
{
int err;
dout("do_request on %p\n", req);
/* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
if (req->r_inode)
ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
if (req->r_locked_dir)
ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
if (req->r_old_dentry)
ceph_get_cap_refs(
ceph_inode(req->r_old_dentry->d_parent->d_inode),
CEPH_CAP_PIN);
/* issue */
mutex_lock(&mdsc->mutex);
__register_request(mdsc, req, dir);
__do_request(mdsc, req);
/* wait */
if (!req->r_reply) {
mutex_unlock(&mdsc->mutex);
if (req->r_timeout) {
err = wait_for_completion_timeout(&req->r_completion,
req->r_timeout);
if (err > 0)
err = 0;
else if (err == 0)
req->r_reply = ERR_PTR(-EIO);
} else {
wait_for_completion(&req->r_completion);
}
mutex_lock(&mdsc->mutex);
}
if (IS_ERR(req->r_reply)) {
err = PTR_ERR(req->r_reply);
req->r_reply = NULL;
/* clean up */
__unregister_request(mdsc, req);
if (!list_empty(&req->r_unsafe_item))
list_del_init(&req->r_unsafe_item);
complete(&req->r_safe_completion);
} else if (req->r_err) {
err = req->r_err;
} else {
err = le32_to_cpu(req->r_reply_info.head->result);
}
mutex_unlock(&mdsc->mutex);
dout("do_request %p done, result %d\n", req, err);
return err;
}
/*
* Handle mds reply.
*
* We take the session mutex and parse and process the reply immediately.
* This preserves the logical ordering of replies, capabilities, etc., sent
* by the MDS as they are applied to our local cache.
*/
static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
{
struct ceph_mds_client *mdsc = session->s_mdsc;
struct ceph_mds_request *req;
struct ceph_mds_reply_head *head = msg->front.iov_base;
struct ceph_mds_reply_info_parsed *rinfo; /* parsed reply info */
u64 tid;
int err, result;
int mds;
if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS)
return;
if (msg->front.iov_len < sizeof(*head)) {
pr_err("mdsc_handle_reply got corrupt (short) reply\n");
return;
}
/* get request, session */
tid = le64_to_cpu(head->tid);
mutex_lock(&mdsc->mutex);
req = __lookup_request(mdsc, tid);
if (!req) {
dout("handle_reply on unknown tid %llu\n", tid);
mutex_unlock(&mdsc->mutex);
return;
}
dout("handle_reply %p\n", req);
mds = le64_to_cpu(msg->hdr.src.name.num);
/* correct session? */
if (!req->r_session && req->r_session != session) {
pr_err("mdsc_handle_reply got %llu on session mds%d"
" not mds%d\n", tid, session->s_mds,
req->r_session ? req->r_session->s_mds : -1);
mutex_unlock(&mdsc->mutex);
goto out;
}
/* dup? */
if ((req->r_got_unsafe && !head->safe) ||
(req->r_got_safe && head->safe)) {
pr_warning("got a dup %s reply on %llu from mds%d\n",
head->safe ? "safe" : "unsafe", tid, mds);
mutex_unlock(&mdsc->mutex);
goto out;
}
result = le32_to_cpu(head->result);
/*
* Tolerate 2 consecutive ESTALEs from the same mds.
* FIXME: we should be looking at the cap migrate_seq.
*/
if (result == -ESTALE) {
req->r_direct_mode = USE_AUTH_MDS;
req->r_num_stale++;
if (req->r_num_stale <= 2) {
__do_request(mdsc, req);
mutex_unlock(&mdsc->mutex);
goto out;
}
} else {
req->r_num_stale = 0;
}
if (head->safe) {
req->r_got_safe = true;
__unregister_request(mdsc, req);
complete(&req->r_safe_completion);
if (req->r_got_unsafe) {
/*
* We already handled the unsafe response, now do the
* cleanup. No need to examine the response; the MDS
* doesn't include any result info in the safe
* response. And even if it did, there is nothing
* useful we could do with a revised return value.
*/
dout("got safe reply %llu, mds%d\n", tid, mds);
list_del_init(&req->r_unsafe_item);
/* last unsafe request during umount? */
if (mdsc->stopping && !__get_oldest_tid(mdsc))
complete(&mdsc->safe_umount_waiters);
mutex_unlock(&mdsc->mutex);
goto out;
}
}
BUG_ON(req->r_reply);
if (!head->safe) {
req->r_got_unsafe = true;
list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
}
dout("handle_reply tid %lld result %d\n", tid, result);
rinfo = &req->r_reply_info;
err = parse_reply_info(msg, rinfo);
mutex_unlock(&mdsc->mutex);
mutex_lock(&session->s_mutex);
if (err < 0) {
pr_err("mdsc_handle_reply got corrupt reply mds%d\n", mds);
goto out_err;
}
/* snap trace */
if (rinfo->snapblob_len) {
down_write(&mdsc->snap_rwsem);
ceph_update_snap_trace(mdsc, rinfo->snapblob,
rinfo->snapblob + rinfo->snapblob_len,
le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP);
downgrade_write(&mdsc->snap_rwsem);
} else {
down_read(&mdsc->snap_rwsem);
}
/* insert trace into our cache */
err = ceph_fill_trace(mdsc->client->sb, req, req->r_session);
if (err == 0) {
if (result == 0 && rinfo->dir_nr)
ceph_readdir_prepopulate(req, req->r_session);
ceph_unreserve_caps(&req->r_caps_reservation);
}
up_read(&mdsc->snap_rwsem);
out_err:
if (err) {
req->r_err = err;
} else {
req->r_reply = msg;
ceph_msg_get(msg);
}
add_cap_releases(mdsc, req->r_session, -1);
mutex_unlock(&session->s_mutex);
/* kick calling process */
complete_request(mdsc, req);
out:
ceph_mdsc_put_request(req);
return;
}
/*
* handle mds notification that our request has been forwarded.
*/
static void handle_forward(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
{
struct ceph_mds_request *req;
u64 tid;
u32 next_mds;
u32 fwd_seq;
u8 must_resend;
int err = -EINVAL;
void *p = msg->front.iov_base;
void *end = p + msg->front.iov_len;
int from_mds, state;
if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS)
goto bad;
from_mds = le64_to_cpu(msg->hdr.src.name.num);
ceph_decode_need(&p, end, sizeof(u64)+2*sizeof(u32), bad);
tid = ceph_decode_64(&p);
next_mds = ceph_decode_32(&p);
fwd_seq = ceph_decode_32(&p);
must_resend = ceph_decode_8(&p);
WARN_ON(must_resend); /* shouldn't happen. */
mutex_lock(&mdsc->mutex);
req = __lookup_request(mdsc, tid);
if (!req) {
dout("forward %llu dne\n", tid);
goto out; /* dup reply? */
}
state = mdsc->sessions[next_mds]->s_state;
if (fwd_seq <= req->r_num_fwd) {
dout("forward %llu to mds%d - old seq %d <= %d\n",
tid, next_mds, req->r_num_fwd, fwd_seq);
} else {
/* resend. forward race not possible; mds would drop */
dout("forward %llu to mds%d (we resend)\n", tid, next_mds);
req->r_num_fwd = fwd_seq;
req->r_resend_mds = next_mds;
put_request_session(req);
__do_request(mdsc, req);
}
ceph_mdsc_put_request(req);
out:
mutex_unlock(&mdsc->mutex);
return;
bad:
pr_err("mdsc_handle_forward decode error err=%d\n", err);
}
/*
* handle a mds session control message
*/
static void handle_session(struct ceph_mds_session *session,
struct ceph_msg *msg)
{
struct ceph_mds_client *mdsc = session->s_mdsc;
u32 op;
u64 seq;
int mds;
struct ceph_mds_session_head *h = msg->front.iov_base;
int wake = 0;
if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS)
return;
mds = le64_to_cpu(msg->hdr.src.name.num);
/* decode */
if (msg->front.iov_len != sizeof(*h))
goto bad;
op = le32_to_cpu(h->op);
seq = le64_to_cpu(h->seq);
mutex_lock(&mdsc->mutex);
/* FIXME: this ttl calculation is generous */
session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
mutex_unlock(&mdsc->mutex);
mutex_lock(&session->s_mutex);
dout("handle_session mds%d %s %p state %s seq %llu\n",
mds, ceph_session_op_name(op), session,
session_state_name(session->s_state), seq);
if (session->s_state == CEPH_MDS_SESSION_HUNG) {
session->s_state = CEPH_MDS_SESSION_OPEN;
pr_info("mds%d came back\n", session->s_mds);
}
switch (op) {
case CEPH_SESSION_OPEN:
session->s_state = CEPH_MDS_SESSION_OPEN;
renewed_caps(mdsc, session, 0);
wake = 1;
if (mdsc->stopping)
__close_session(mdsc, session);
break;
case CEPH_SESSION_RENEWCAPS:
if (session->s_renew_seq == seq)
renewed_caps(mdsc, session, 1);
break;
case CEPH_SESSION_CLOSE:
unregister_session(mdsc, mds);
remove_session_caps(session);
wake = 1; /* for good measure */
complete(&mdsc->session_close_waiters);
kick_requests(mdsc, mds, 0); /* cur only */
break;
case CEPH_SESSION_STALE:
pr_info("mds%d caps went stale, renewing\n",
session->s_mds);
spin_lock(&session->s_cap_lock);
session->s_cap_gen++;
session->s_cap_ttl = 0;
spin_unlock(&session->s_cap_lock);
send_renew_caps(mdsc, session);
break;
case CEPH_SESSION_RECALL_STATE:
trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
break;
default:
pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
WARN_ON(1);
}
mutex_unlock(&session->s_mutex);
if (wake) {
mutex_lock(&mdsc->mutex);
__wake_requests(mdsc, &session->s_waiting);
mutex_unlock(&mdsc->mutex);
}
return;
bad:
pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
(int)msg->front.iov_len);
return;
}
/*
* called under session->mutex.
*/
static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_mds_request *req, *nreq;
int err;
dout("replay_unsafe_requests mds%d\n", session->s_mds);
mutex_lock(&mdsc->mutex);
list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
err = __prepare_send_request(mdsc, req, session->s_mds);
if (!err) {
ceph_msg_get(req->r_request);
ceph_con_send(&session->s_con, req->r_request);
}
}
mutex_unlock(&mdsc->mutex);
}
/*
* Encode information about a cap for a reconnect with the MDS.
*/
struct encode_caps_data {
void **pp;
void *end;
int *num_caps;
};
static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
void *arg)
{
struct ceph_mds_cap_reconnect *rec;
struct ceph_inode_info *ci;
struct encode_caps_data *data = (struct encode_caps_data *)arg;
void *p = *(data->pp);
void *end = data->end;
char *path;
int pathlen, err;
u64 pathbase;
struct dentry *dentry;
ci = cap->ci;
dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
inode, ceph_vinop(inode), cap, cap->cap_id,
ceph_cap_string(cap->issued));
ceph_decode_need(&p, end, sizeof(u64), needmore);
ceph_encode_64(&p, ceph_ino(inode));
dentry = d_find_alias(inode);
if (dentry) {
path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
if (IS_ERR(path)) {
err = PTR_ERR(path);
BUG_ON(err);
}
} else {
path = NULL;
pathlen = 0;
}
ceph_decode_need(&p, end, pathlen+4, needmore);
ceph_encode_string(&p, end, path, pathlen);
ceph_decode_need(&p, end, sizeof(*rec), needmore);
rec = p;
p += sizeof(*rec);
BUG_ON(p > end);
spin_lock(&inode->i_lock);
cap->seq = 0; /* reset cap seq */
cap->issue_seq = 0; /* and issue_seq */
rec->cap_id = cpu_to_le64(cap->cap_id);
rec->pathbase = cpu_to_le64(pathbase);
rec->wanted = cpu_to_le32(__ceph_caps_wanted(ci));
rec->issued = cpu_to_le32(cap->issued);
rec->size = cpu_to_le64(inode->i_size);
ceph_encode_timespec(&rec->mtime, &inode->i_mtime);
ceph_encode_timespec(&rec->atime, &inode->i_atime);
rec->snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
spin_unlock(&inode->i_lock);
kfree(path);
dput(dentry);
(*data->num_caps)++;
*(data->pp) = p;
return 0;
needmore:
return -ENOSPC;
}
/*
* If an MDS fails and recovers, clients need to reconnect in order to
* reestablish shared state. This includes all caps issued through
* this session _and_ the snap_realm hierarchy. Because it's not
* clear which snap realms the mds cares about, we send everything we
* know about.. that ensures we'll then get any new info the
* recovering MDS might have.
*
* This is a relatively heavyweight operation, but it's rare.
*
* called with mdsc->mutex held.
*/
static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds)
{
struct ceph_mds_session *session;
struct ceph_msg *reply;
int newlen, len = 4 + 1;
void *p, *end;
int err;
int num_caps, num_realms = 0;
int got;
u64 next_snap_ino = 0;
__le32 *pnum_caps, *pnum_realms;
struct encode_caps_data iter_args;
pr_info("reconnect to recovering mds%d\n", mds);
/* find session */
session = __ceph_lookup_mds_session(mdsc, mds);
mutex_unlock(&mdsc->mutex); /* drop lock for duration */
if (session) {
mutex_lock(&session->s_mutex);
session->s_state = CEPH_MDS_SESSION_RECONNECTING;
session->s_seq = 0;
ceph_con_open(&session->s_con,
ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
/* replay unsafe requests */
replay_unsafe_requests(mdsc, session);
/* estimate needed space */
len += session->s_nr_caps *
(100+sizeof(struct ceph_mds_cap_reconnect));
pr_info("estimating i need %d bytes for %d caps\n",
len, session->s_nr_caps);
} else {
dout("no session for mds%d, will send short reconnect\n",
mds);
}
down_read(&mdsc->snap_rwsem);
retry:
/* build reply */
reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, len, 0, 0, NULL);
if (IS_ERR(reply)) {
err = PTR_ERR(reply);
pr_err("send_mds_reconnect ENOMEM on %d for mds%d\n",
len, mds);
goto out;
}
p = reply->front.iov_base;
end = p + len;
if (!session) {
ceph_encode_8(&p, 1); /* session was closed */
ceph_encode_32(&p, 0);
goto send;
}
dout("session %p state %s\n", session,
session_state_name(session->s_state));
/* traverse this session's caps */
ceph_encode_8(&p, 0);
pnum_caps = p;
ceph_encode_32(&p, session->s_nr_caps);
num_caps = 0;
iter_args.pp = &p;
iter_args.end = end;
iter_args.num_caps = &num_caps;
err = iterate_session_caps(session, encode_caps_cb, &iter_args);
if (err == -ENOSPC)
goto needmore;
if (err < 0)
goto out;
*pnum_caps = cpu_to_le32(num_caps);
/*
* 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.
*/
next_snap_ino = 0;
/* save some space for the snaprealm count */
pnum_realms = p;
ceph_decode_need(&p, end, sizeof(*pnum_realms), needmore);
p += sizeof(*pnum_realms);
num_realms = 0;
while (1) {
struct ceph_snap_realm *realm;
struct ceph_mds_snaprealm_reconnect *sr_rec;
got = radix_tree_gang_lookup(&mdsc->snap_realms,
(void **)&realm, next_snap_ino, 1);
if (!got)
break;
dout(" adding snap realm %llx seq %lld parent %llx\n",
realm->ino, realm->seq, realm->parent_ino);
ceph_decode_need(&p, end, sizeof(*sr_rec), needmore);
sr_rec = p;
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);
p += sizeof(*sr_rec);
num_realms++;
next_snap_ino = realm->ino + 1;
}
*pnum_realms = cpu_to_le32(num_realms);
send:
reply->front.iov_len = p - reply->front.iov_base;
reply->hdr.front_len = cpu_to_le32(reply->front.iov_len);
dout("final len was %u (guessed %d)\n",
(unsigned)reply->front.iov_len, len);
ceph_con_send(&session->s_con, reply);
if (session) {
session->s_state = CEPH_MDS_SESSION_OPEN;
__wake_requests(mdsc, &session->s_waiting);
}
out:
up_read(&mdsc->snap_rwsem);
if (session) {
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
}
mutex_lock(&mdsc->mutex);
return;
needmore:
/*
* we need a larger buffer. this doesn't very accurately
* factor in snap realms, but it's safe.
*/
num_caps += num_realms;
newlen = len * ((100 * (session->s_nr_caps+3)) / (num_caps + 1)) / 100;
pr_info("i guessed %d, and did %d of %d caps, retrying with %d\n",
len, num_caps, session->s_nr_caps, newlen);
len = newlen;
ceph_msg_put(reply);
goto retry;
}
/*
* compare old and new mdsmaps, kicking requests
* and closing out old connections as necessary
*
* called under mdsc->mutex.
*/
static void check_new_map(struct ceph_mds_client *mdsc,
struct ceph_mdsmap *newmap,
struct ceph_mdsmap *oldmap)
{
int i;
int oldstate, newstate;
struct ceph_mds_session *s;
dout("check_new_map new %u old %u\n",
newmap->m_epoch, oldmap->m_epoch);
for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
if (mdsc->sessions[i] == NULL)
continue;
s = mdsc->sessions[i];
oldstate = ceph_mdsmap_get_state(oldmap, i);
newstate = ceph_mdsmap_get_state(newmap, i);
dout("check_new_map mds%d state %s -> %s (session %s)\n",
i, ceph_mds_state_name(oldstate),
ceph_mds_state_name(newstate),
session_state_name(s->s_state));
if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
ceph_mdsmap_get_addr(newmap, i),
sizeof(struct ceph_entity_addr))) {
if (s->s_state == CEPH_MDS_SESSION_OPENING) {
/* the session never opened, just close it
* out now */
__wake_requests(mdsc, &s->s_waiting);
unregister_session(mdsc, i);
} else {
/* just close it */
mutex_unlock(&mdsc->mutex);
mutex_lock(&s->s_mutex);
mutex_lock(&mdsc->mutex);
ceph_con_close(&s->s_con);
mutex_unlock(&s->s_mutex);
s->s_state = CEPH_MDS_SESSION_RESTARTING;
}
/* kick any requests waiting on the recovering mds */
kick_requests(mdsc, i, 1);
} else if (oldstate == newstate) {
continue; /* nothing new with this mds */
}
/*
* send reconnect?
*/
if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
newstate >= CEPH_MDS_STATE_RECONNECT)
send_mds_reconnect(mdsc, i);
/*
* kick requests on any mds that has gone active.
*
* kick requests on cur or forwarder: we may have sent
* the request to mds1, mds1 told us it forwarded it
* to mds2, but then we learn mds1 failed and can't be
* sure it successfully forwarded our request before
* it died.
*/
if (oldstate < CEPH_MDS_STATE_ACTIVE &&
newstate >= CEPH_MDS_STATE_ACTIVE) {
kick_requests(mdsc, i, 1);
ceph_kick_flushing_caps(mdsc, s);
}
}
}
/*
* leases
*/
/*
* caller must hold session s_mutex, dentry->d_lock
*/
void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
{
struct ceph_dentry_info *di = ceph_dentry(dentry);
ceph_put_mds_session(di->lease_session);
di->lease_session = NULL;
}
static void handle_lease(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
{
struct super_block *sb = mdsc->client->sb;
struct inode *inode;
struct ceph_mds_session *session;
struct ceph_inode_info *ci;
struct dentry *parent, *dentry;
struct ceph_dentry_info *di;
int mds;
struct ceph_mds_lease *h = msg->front.iov_base;
struct ceph_vino vino;
int mask;
struct qstr dname;
int release = 0;
if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS)
return;
mds = le64_to_cpu(msg->hdr.src.name.num);
dout("handle_lease from mds%d\n", mds);
/* decode */
if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
goto bad;
vino.ino = le64_to_cpu(h->ino);
vino.snap = CEPH_NOSNAP;
mask = le16_to_cpu(h->mask);
dname.name = (void *)h + sizeof(*h) + sizeof(u32);
dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
if (dname.len != get_unaligned_le32(h+1))
goto bad;
/* find session */
mutex_lock(&mdsc->mutex);
session = __ceph_lookup_mds_session(mdsc, mds);
mutex_unlock(&mdsc->mutex);
if (!session) {
pr_err("handle_lease got lease but no session mds%d\n", mds);
return;
}
mutex_lock(&session->s_mutex);
session->s_seq++;
/* lookup inode */
inode = ceph_find_inode(sb, vino);
dout("handle_lease '%s', mask %d, ino %llx %p\n",
ceph_lease_op_name(h->action), mask, vino.ino, inode);
if (inode == NULL) {
dout("handle_lease no inode %llx\n", vino.ino);
goto release;
}
ci = ceph_inode(inode);
/* dentry */
parent = d_find_alias(inode);
if (!parent) {
dout("no parent dentry on inode %p\n", inode);
WARN_ON(1);
goto release; /* hrm... */
}
dname.hash = full_name_hash(dname.name, dname.len);
dentry = d_lookup(parent, &dname);
dput(parent);
if (!dentry)
goto release;
spin_lock(&dentry->d_lock);
di = ceph_dentry(dentry);
switch (h->action) {
case CEPH_MDS_LEASE_REVOKE:
if (di && di->lease_session == session) {
h->seq = cpu_to_le32(di->lease_seq);
__ceph_mdsc_drop_dentry_lease(dentry);
}
release = 1;
break;
case CEPH_MDS_LEASE_RENEW:
if (di && di->lease_session == session &&
di->lease_gen == session->s_cap_gen &&
di->lease_renew_from &&
di->lease_renew_after == 0) {
unsigned long duration =
le32_to_cpu(h->duration_ms) * HZ / 1000;
di->lease_seq = le32_to_cpu(h->seq);
dentry->d_time = di->lease_renew_from + duration;
di->lease_renew_after = di->lease_renew_from +
(duration >> 1);
di->lease_renew_from = 0;
}
break;
}
spin_unlock(&dentry->d_lock);
dput(dentry);
if (!release)
goto out;
release:
/* let's just reuse the same message */
h->action = CEPH_MDS_LEASE_REVOKE_ACK;
ceph_msg_get(msg);
ceph_con_send(&session->s_con, msg);
out:
iput(inode);
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
return;
bad:
pr_err("corrupt lease message\n");
}
void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
struct inode *inode,
struct dentry *dentry, char action,
u32 seq)
{
struct ceph_msg *msg;
struct ceph_mds_lease *lease;
int len = sizeof(*lease) + sizeof(u32);
int dnamelen = 0;
dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
inode, dentry, ceph_lease_op_name(action), session->s_mds);
dnamelen = dentry->d_name.len;
len += dnamelen;
msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, 0, 0, NULL);
if (IS_ERR(msg))
return;
lease = msg->front.iov_base;
lease->action = action;
lease->mask = cpu_to_le16(CEPH_LOCK_DN);
lease->ino = cpu_to_le64(ceph_vino(inode).ino);
lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
lease->seq = cpu_to_le32(seq);
put_unaligned_le32(dnamelen, lease + 1);
memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
/*
* if this is a preemptive lease RELEASE, no need to
* flush request stream, since the actual request will
* soon follow.
*/
msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
ceph_con_send(&session->s_con, msg);
}
/*
* Preemptively release a lease we expect to invalidate anyway.
* Pass @inode always, @dentry is optional.
*/
void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
struct dentry *dentry, int mask)
{
struct ceph_dentry_info *di;
struct ceph_mds_session *session;
u32 seq;
BUG_ON(inode == NULL);
BUG_ON(dentry == NULL);
BUG_ON(mask != CEPH_LOCK_DN);
/* is dentry lease valid? */
spin_lock(&dentry->d_lock);
di = ceph_dentry(dentry);
if (!di || !di->lease_session ||
di->lease_session->s_mds < 0 ||
di->lease_gen != di->lease_session->s_cap_gen ||
!time_before(jiffies, dentry->d_time)) {
dout("lease_release inode %p dentry %p -- "
"no lease on %d\n",
inode, dentry, mask);
spin_unlock(&dentry->d_lock);
return;
}
/* we do have a lease on this dentry; note mds and seq */
session = ceph_get_mds_session(di->lease_session);
seq = di->lease_seq;
__ceph_mdsc_drop_dentry_lease(dentry);
spin_unlock(&dentry->d_lock);
dout("lease_release inode %p dentry %p mask %d to mds%d\n",
inode, dentry, mask, session->s_mds);
ceph_mdsc_lease_send_msg(session, inode, dentry,
CEPH_MDS_LEASE_RELEASE, seq);
ceph_put_mds_session(session);
}
/*
* drop all leases (and dentry refs) in preparation for umount
*/
static void drop_leases(struct ceph_mds_client *mdsc)
{
int i;
dout("drop_leases\n");
mutex_lock(&mdsc->mutex);
for (i = 0; i < mdsc->max_sessions; i++) {
struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
if (!s)
continue;
mutex_unlock(&mdsc->mutex);
mutex_lock(&s->s_mutex);
mutex_unlock(&s->s_mutex);
ceph_put_mds_session(s);
mutex_lock(&mdsc->mutex);
}
mutex_unlock(&mdsc->mutex);
}
/*
* delayed work -- periodically trim expired leases, renew caps with mds
*/
static void schedule_delayed(struct ceph_mds_client *mdsc)
{
int delay = 5;
unsigned hz = round_jiffies_relative(HZ * delay);
schedule_delayed_work(&mdsc->delayed_work, hz);
}
static void delayed_work(struct work_struct *work)
{
int i;
struct ceph_mds_client *mdsc =
container_of(work, struct ceph_mds_client, delayed_work.work);
int renew_interval;
int renew_caps;
dout("mdsc delayed_work\n");
ceph_check_delayed_caps(mdsc);
mutex_lock(&mdsc->mutex);
renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
renew_caps = time_after_eq(jiffies, HZ*renew_interval +
mdsc->last_renew_caps);
if (renew_caps)
mdsc->last_renew_caps = jiffies;
for (i = 0; i < mdsc->max_sessions; i++) {
struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
if (s == NULL)
continue;
if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
dout("resending session close request for mds%d\n",
s->s_mds);
request_close_session(mdsc, s);
ceph_put_mds_session(s);
continue;
}
if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
if (s->s_state == CEPH_MDS_SESSION_OPEN) {
s->s_state = CEPH_MDS_SESSION_HUNG;
pr_info("mds%d hung\n", s->s_mds);
}
}
if (s->s_state < CEPH_MDS_SESSION_OPEN) {
/* this mds is failed or recovering, just wait */
ceph_put_mds_session(s);
continue;
}
mutex_unlock(&mdsc->mutex);
mutex_lock(&s->s_mutex);
if (renew_caps)
send_renew_caps(mdsc, s);
else
ceph_con_keepalive(&s->s_con);
add_cap_releases(mdsc, s, -1);
send_cap_releases(mdsc, s);
mutex_unlock(&s->s_mutex);
ceph_put_mds_session(s);
mutex_lock(&mdsc->mutex);
}
mutex_unlock(&mdsc->mutex);
schedule_delayed(mdsc);
}
void ceph_mdsc_init(struct ceph_mds_client *mdsc, struct ceph_client *client)
{
mdsc->client = client;
mutex_init(&mdsc->mutex);
mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
init_completion(&mdsc->safe_umount_waiters);
init_completion(&mdsc->session_close_waiters);
INIT_LIST_HEAD(&mdsc->waiting_for_map);
mdsc->sessions = NULL;
mdsc->max_sessions = 0;
mdsc->stopping = 0;
init_rwsem(&mdsc->snap_rwsem);
INIT_RADIX_TREE(&mdsc->snap_realms, GFP_NOFS);
INIT_LIST_HEAD(&mdsc->snap_empty);
spin_lock_init(&mdsc->snap_empty_lock);
mdsc->last_tid = 0;
INIT_RADIX_TREE(&mdsc->request_tree, GFP_NOFS);
INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
mdsc->last_renew_caps = jiffies;
INIT_LIST_HEAD(&mdsc->cap_delay_list);
spin_lock_init(&mdsc->cap_delay_lock);
INIT_LIST_HEAD(&mdsc->snap_flush_list);
spin_lock_init(&mdsc->snap_flush_lock);
mdsc->cap_flush_seq = 0;
INIT_LIST_HEAD(&mdsc->cap_dirty);
mdsc->num_cap_flushing = 0;
spin_lock_init(&mdsc->cap_dirty_lock);
init_waitqueue_head(&mdsc->cap_flushing_wq);
spin_lock_init(&mdsc->dentry_lru_lock);
INIT_LIST_HEAD(&mdsc->dentry_lru);
}
/*
* Wait for safe replies on open mds requests. If we time out, drop
* all requests from the tree to avoid dangling dentry refs.
*/
static void wait_requests(struct ceph_mds_client *mdsc)
{
struct ceph_mds_request *req;
struct ceph_client *client = mdsc->client;
mutex_lock(&mdsc->mutex);
if (__get_oldest_tid(mdsc)) {
mutex_unlock(&mdsc->mutex);
dout("wait_requests waiting for requests\n");
wait_for_completion_timeout(&mdsc->safe_umount_waiters,
client->mount_args.mount_timeout * HZ);
mutex_lock(&mdsc->mutex);
/* tear down remaining requests */
while (radix_tree_gang_lookup(&mdsc->request_tree,
(void **)&req, 0, 1)) {
dout("wait_requests timed out on tid %llu\n",
req->r_tid);
radix_tree_delete(&mdsc->request_tree, req->r_tid);
ceph_mdsc_put_request(req);
}
}
mutex_unlock(&mdsc->mutex);
dout("wait_requests done\n");
}
/*
* called before mount is ro, and before dentries are torn down.
* (hmm, does this still race with new lookups?)
*/
void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
{
dout("pre_umount\n");
mdsc->stopping = 1;
drop_leases(mdsc);
ceph_flush_dirty_caps(mdsc);
wait_requests(mdsc);
}
/*
* wait for all write mds requests to flush.
*/
static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
{
struct ceph_mds_request *req;
u64 next_tid = 0;
int got;
mutex_lock(&mdsc->mutex);
dout("wait_unsafe_requests want %lld\n", want_tid);
while (1) {
got = radix_tree_gang_lookup(&mdsc->request_tree, (void **)&req,
next_tid, 1);
if (!got)
break;
if (req->r_tid > want_tid)
break;
next_tid = req->r_tid + 1;
if ((req->r_op & CEPH_MDS_OP_WRITE) == 0)
continue; /* not a write op */
ceph_mdsc_get_request(req);
mutex_unlock(&mdsc->mutex);
dout("wait_unsafe_requests wait on %llu (want %llu)\n",
req->r_tid, want_tid);
wait_for_completion(&req->r_safe_completion);
mutex_lock(&mdsc->mutex);
ceph_mdsc_put_request(req);
}
mutex_unlock(&mdsc->mutex);
dout("wait_unsafe_requests done\n");
}
void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
{
u64 want_tid, want_flush;
dout("sync\n");
mutex_lock(&mdsc->mutex);
want_tid = mdsc->last_tid;
want_flush = mdsc->cap_flush_seq;
mutex_unlock(&mdsc->mutex);
dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush);
ceph_flush_dirty_caps(mdsc);
wait_unsafe_requests(mdsc, want_tid);
wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush));
}
/*
* called after sb is ro.
*/
void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
{
struct ceph_mds_session *session;
int i;
int n;
struct ceph_client *client = mdsc->client;
unsigned long started, timeout = client->mount_args.mount_timeout * HZ;
dout("close_sessions\n");
mutex_lock(&mdsc->mutex);
/* close sessions */
started = jiffies;
while (time_before(jiffies, started + timeout)) {
dout("closing sessions\n");
n = 0;
for (i = 0; i < mdsc->max_sessions; i++) {
session = __ceph_lookup_mds_session(mdsc, i);
if (!session)
continue;
mutex_unlock(&mdsc->mutex);
mutex_lock(&session->s_mutex);
__close_session(mdsc, session);
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
mutex_lock(&mdsc->mutex);
n++;
}
if (n == 0)
break;
if (client->mount_state == CEPH_MOUNT_SHUTDOWN)
break;
dout("waiting for sessions to close\n");
mutex_unlock(&mdsc->mutex);
wait_for_completion_timeout(&mdsc->session_close_waiters,
timeout);
mutex_lock(&mdsc->mutex);
}
/* tear down remaining sessions */
for (i = 0; i < mdsc->max_sessions; i++) {
if (mdsc->sessions[i]) {
session = get_session(mdsc->sessions[i]);
unregister_session(mdsc, i);
mutex_unlock(&mdsc->mutex);
mutex_lock(&session->s_mutex);
remove_session_caps(session);
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
mutex_lock(&mdsc->mutex);
}
}
WARN_ON(!list_empty(&mdsc->cap_delay_list));
mutex_unlock(&mdsc->mutex);
ceph_cleanup_empty_realms(mdsc);
cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
dout("stopped\n");
}
void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
{
dout("stop\n");
cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
if (mdsc->mdsmap)
ceph_mdsmap_destroy(mdsc->mdsmap);
kfree(mdsc->sessions);
}
/*
* handle mds map update.
*/
void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
{
u32 epoch;
u32 maplen;
void *p = msg->front.iov_base;
void *end = p + msg->front.iov_len;
struct ceph_mdsmap *newmap, *oldmap;
struct ceph_fsid fsid;
int err = -EINVAL;
ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
ceph_decode_copy(&p, &fsid, sizeof(fsid));
if (ceph_fsid_compare(&fsid, &mdsc->client->monc.monmap->fsid)) {
pr_err("got mdsmap with wrong fsid\n");
return;
}
epoch = ceph_decode_32(&p);
maplen = ceph_decode_32(&p);
dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
/* do we need it? */
ceph_monc_got_mdsmap(&mdsc->client->monc, epoch);
mutex_lock(&mdsc->mutex);
if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
dout("handle_map epoch %u <= our %u\n",
epoch, mdsc->mdsmap->m_epoch);
mutex_unlock(&mdsc->mutex);
return;
}
newmap = ceph_mdsmap_decode(&p, end);
if (IS_ERR(newmap)) {
err = PTR_ERR(newmap);
goto bad_unlock;
}
/* swap into place */
if (mdsc->mdsmap) {
oldmap = mdsc->mdsmap;
mdsc->mdsmap = newmap;
check_new_map(mdsc, newmap, oldmap);
ceph_mdsmap_destroy(oldmap);
} else {
mdsc->mdsmap = newmap; /* first mds map */
}
mdsc->client->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
__wake_requests(mdsc, &mdsc->waiting_for_map);
mutex_unlock(&mdsc->mutex);
schedule_delayed(mdsc);
return;
bad_unlock:
mutex_unlock(&mdsc->mutex);
bad:
pr_err("error decoding mdsmap %d\n", err);
return;
}
static struct ceph_connection *con_get(struct ceph_connection *con)
{
struct ceph_mds_session *s = con->private;
if (get_session(s)) {
dout("mdsc con_get %p %d -> %d\n", s,
atomic_read(&s->s_ref) - 1, atomic_read(&s->s_ref));
return con;
}
dout("mdsc con_get %p FAIL\n", s);
return NULL;
}
static void con_put(struct ceph_connection *con)
{
struct ceph_mds_session *s = con->private;
dout("mdsc con_put %p %d -> %d\n", s, atomic_read(&s->s_ref),
atomic_read(&s->s_ref) - 1);
ceph_put_mds_session(s);
}
/*
* if the client is unresponsive for long enough, the mds will kill
* the session entirely.
*/
static void peer_reset(struct ceph_connection *con)
{
struct ceph_mds_session *s = con->private;
pr_err("mds%d gave us the boot. IMPLEMENT RECONNECT.\n",
s->s_mds);
}
static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
{
struct ceph_mds_session *s = con->private;
struct ceph_mds_client *mdsc = s->s_mdsc;
int type = le16_to_cpu(msg->hdr.type);
switch (type) {
case CEPH_MSG_MDS_MAP:
ceph_mdsc_handle_map(mdsc, msg);
break;
case CEPH_MSG_CLIENT_SESSION:
handle_session(s, msg);
break;
case CEPH_MSG_CLIENT_REPLY:
handle_reply(s, msg);
break;
case CEPH_MSG_CLIENT_REQUEST_FORWARD:
handle_forward(mdsc, msg);
break;
case CEPH_MSG_CLIENT_CAPS:
ceph_handle_caps(s, msg);
break;
case CEPH_MSG_CLIENT_SNAP:
ceph_handle_snap(mdsc, msg);
break;
case CEPH_MSG_CLIENT_LEASE:
handle_lease(mdsc, msg);
break;
default:
pr_err("received unknown message type %d %s\n", type,
ceph_msg_type_name(type));
}
ceph_msg_put(msg);
}
const static struct ceph_connection_operations mds_con_ops = {
.get = con_get,
.put = con_put,
.dispatch = dispatch,
.peer_reset = peer_reset,
.alloc_msg = ceph_alloc_msg,
.alloc_middle = ceph_alloc_middle,
};
/* eof */
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