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ceph: don't pre-allocate space for cap release messages

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Previously we pre-allocate cap release messages for each caps. This
wastes lots of memory when there are large amount of caps. This patch
make the code not pre-allocate the cap release messages. Instead,
we add the corresponding ceph_cap struct to a list when releasing a
cap. Later when flush cap releases is needed, we allocate the cap
release messages dynamically.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
This commit is contained in:
Yan, Zheng 2015-05-14 17:22:42 +08:00 committed by Ilya Dryomov
parent affbc19a68
commit 745a8e3bcc
4 changed files with 133 additions and 206 deletions
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85
fs/ceph/caps.c
View File

@ -926,16 +926,6 @@ void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release)
/* remove from session list */
spin_lock(&session->s_cap_lock);
/*
* s_cap_reconnect is protected by s_cap_lock. no one changes
* s_cap_gen while session is in the reconnect state.
*/
if (queue_release &&
(!session->s_cap_reconnect ||
cap->cap_gen == session->s_cap_gen))
__queue_cap_release(session, ci->i_vino.ino, cap->cap_id,
cap->mseq, cap->issue_seq);
if (session->s_cap_iterator == cap) {
/* not yet, we are iterating over this very cap */
dout("__ceph_remove_cap delaying %p removal from session %p\n",
@ -948,6 +938,25 @@ void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release)
}
/* protect backpointer with s_cap_lock: see iterate_session_caps */
cap->ci = NULL;
/*
* s_cap_reconnect is protected by s_cap_lock. no one changes
* s_cap_gen while session is in the reconnect state.
*/
if (queue_release &&
(!session->s_cap_reconnect || cap->cap_gen == session->s_cap_gen)) {
cap->queue_release = 1;
if (removed) {
list_add_tail(&cap->session_caps,
&session->s_cap_releases);
session->s_num_cap_releases++;
removed = 0;
}
} else {
cap->queue_release = 0;
}
cap->cap_ino = ci->i_vino.ino;
spin_unlock(&session->s_cap_lock);
/* remove from inode list */
@ -1053,44 +1062,6 @@ static int send_cap_msg(struct ceph_mds_session *session,
return 0;
}
void __queue_cap_release(struct ceph_mds_session *session,
u64 ino, u64 cap_id, u32 migrate_seq,
u32 issue_seq)
{
struct ceph_msg *msg;
struct ceph_mds_cap_release *head;
struct ceph_mds_cap_item *item;
BUG_ON(!session->s_num_cap_releases);
msg = list_first_entry(&session->s_cap_releases,
struct ceph_msg, list_head);
dout(" adding %llx release to mds%d msg %p (%d left)\n",
ino, session->s_mds, msg, session->s_num_cap_releases);
BUG_ON(msg->front.iov_len + sizeof(*item) > PAGE_CACHE_SIZE);
head = msg->front.iov_base;
le32_add_cpu(&head->num, 1);
item = msg->front.iov_base + msg->front.iov_len;
item->ino = cpu_to_le64(ino);
item->cap_id = cpu_to_le64(cap_id);
item->migrate_seq = cpu_to_le32(migrate_seq);
item->seq = cpu_to_le32(issue_seq);
session->s_num_cap_releases--;
msg->front.iov_len += sizeof(*item);
if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
dout(" release msg %p full\n", msg);
list_move_tail(&msg->list_head, &session->s_cap_releases_done);
} else {
dout(" release msg %p at %d/%d (%d)\n", msg,
(int)le32_to_cpu(head->num),
(int)CEPH_CAPS_PER_RELEASE,
(int)msg->front.iov_len);
}
}
/*
* Queue cap releases when an inode is dropped from our cache. Since
* inode is about to be destroyed, there is no need for i_ceph_lock.
@ -3051,7 +3022,6 @@ retry:
mutex_lock_nested(&session->s_mutex,
SINGLE_DEPTH_NESTING);
}
ceph_add_cap_releases(mdsc, tsession);
new_cap = ceph_get_cap(mdsc, NULL);
} else {
WARN_ON(1);
@ -3247,16 +3217,20 @@ void ceph_handle_caps(struct ceph_mds_session *session,
dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
(unsigned)seq);
if (op == CEPH_CAP_OP_IMPORT)
ceph_add_cap_releases(mdsc, session);
if (!inode) {
dout(" i don't have ino %llx\n", vino.ino);
if (op == CEPH_CAP_OP_IMPORT) {
cap = ceph_get_cap(mdsc, NULL);
cap->cap_ino = vino.ino;
cap->queue_release = 1;
cap->cap_id = cap_id;
cap->mseq = mseq;
cap->seq = seq;
spin_lock(&session->s_cap_lock);
__queue_cap_release(session, vino.ino, cap_id,
mseq, seq);
list_add_tail(&cap->session_caps,
&session->s_cap_releases);
session->s_num_cap_releases++;
spin_unlock(&session->s_cap_lock);
}
goto flush_cap_releases;
@ -3332,11 +3306,10 @@ void ceph_handle_caps(struct ceph_mds_session *session,
flush_cap_releases:
/*
* send any full release message to try to move things
* send any cap release message to try to move things
* along for the mds (who clearly thinks we still have this
* cap).
*/
ceph_add_cap_releases(mdsc, session);
ceph_send_cap_releases(mdsc, session);
done:

225
fs/ceph/mds_client.c
View File

@ -458,7 +458,6 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
s->s_cap_reconnect = 0;
s->s_cap_iterator = NULL;
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);
@ -998,27 +997,25 @@ void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
* session caps
*/
/*
* Free preallocated cap messages assigned to this session
*/
static void cleanup_cap_releases(struct ceph_mds_session *session)
/* caller holds s_cap_lock, we drop it */
static void cleanup_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
__releases(session->s_cap_lock)
{
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);
}
LIST_HEAD(tmp_list);
list_splice_init(&session->s_cap_releases, &tmp_list);
session->s_num_cap_releases = 0;
spin_unlock(&session->s_cap_lock);
dout("cleanup_cap_releases mds%d\n", session->s_mds);
while (!list_empty(&tmp_list)) {
struct ceph_cap *cap;
/* zero out the in-progress message */
cap = list_first_entry(&tmp_list,
struct ceph_cap, session_caps);
list_del(&cap->session_caps);
ceph_put_cap(mdsc, cap);
}
}
static void cleanup_session_requests(struct ceph_mds_client *mdsc,
@ -1095,11 +1092,17 @@ static int iterate_session_caps(struct ceph_mds_session *session,
dout("iterate_session_caps finishing cap %p removal\n",
cap);
BUG_ON(cap->session != session);
cap->session = NULL;
list_del_init(&cap->session_caps);
session->s_nr_caps--;
cap->session = NULL;
if (cap->queue_release) {
list_add_tail(&cap->session_caps,
&session->s_cap_releases);
session->s_num_cap_releases++;
} else {
old_cap = cap; /* put_cap it w/o locks held */
}
}
if (ret < 0)
goto out;
}
@ -1191,11 +1194,12 @@ static void remove_session_caps(struct ceph_mds_session *session)
spin_lock(&session->s_cap_lock);
}
}
spin_unlock(&session->s_cap_lock);
// drop cap expires and unlock s_cap_lock
cleanup_cap_releases(session->s_mdsc, session);
BUG_ON(session->s_nr_caps > 0);
BUG_ON(!list_empty(&session->s_cap_flushing));
cleanup_cap_releases(session);
}
/*
@ -1418,76 +1422,10 @@ static int trim_caps(struct ceph_mds_client *mdsc,
session->s_trim_caps = 0;
}
ceph_add_cap_releases(mdsc, session);
ceph_send_cap_releases(mdsc, session);
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.
*/
int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_msg *msg, *partial = NULL;
struct ceph_mds_cap_release *head;
int err = -ENOMEM;
int extra = mdsc->fsc->mount_options->cap_release_safety;
int num;
dout("add_cap_releases %p mds%d extra %d\n", session, session->s_mds,
extra);
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;
num = le32_to_cpu(head->num);
if (num) {
dout(" partial %p with (%d/%d)\n", msg, num,
(int)CEPH_CAPS_PER_RELEASE);
extra += CEPH_CAPS_PER_RELEASE - num;
partial = msg;
}
}
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,
GFP_NOFS, false);
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 (partial) {
head = partial->front.iov_base;
num = le32_to_cpu(head->num);
dout(" queueing partial %p with %d/%d\n", partial, num,
(int)CEPH_CAPS_PER_RELEASE);
list_move_tail(&partial->list_head,
&session->s_cap_releases_done);
session->s_num_cap_releases -= CEPH_CAPS_PER_RELEASE - num;
}
err = 0;
spin_unlock(&session->s_cap_lock);
out_unlocked:
return err;
}
static int check_cap_flush(struct ceph_inode_info *ci,
u64 want_flush_seq, u64 want_snap_seq)
{
@ -1590,60 +1528,74 @@ static void wait_caps_flush(struct ceph_mds_client *mdsc,
void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_msg *msg;
struct ceph_msg *msg = NULL;
struct ceph_mds_cap_release *head;
struct ceph_mds_cap_item *item;
struct ceph_cap *cap;
LIST_HEAD(tmp_list);
int num_cap_releases;
dout("send_cap_releases mds%d\n", session->s_mds);
spin_lock(&session->s_cap_lock);
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);
again:
list_splice_init(&session->s_cap_releases, &tmp_list);
num_cap_releases = session->s_num_cap_releases;
session->s_num_cap_releases = 0;
spin_unlock(&session->s_cap_lock);
while (!list_empty(&tmp_list)) {
if (!msg) {
msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
PAGE_CACHE_SIZE, GFP_NOFS, false);
if (!msg)
goto out_err;
head = msg->front.iov_base;
head->num = cpu_to_le32(0);
msg->front.iov_len = sizeof(*head);
}
cap = list_first_entry(&tmp_list, struct ceph_cap,
session_caps);
list_del(&cap->session_caps);
num_cap_releases--;
head = msg->front.iov_base;
le32_add_cpu(&head->num, 1);
item = msg->front.iov_base + msg->front.iov_len;
item->ino = cpu_to_le64(cap->cap_ino);
item->cap_id = cpu_to_le64(cap->cap_id);
item->migrate_seq = cpu_to_le32(cap->mseq);
item->seq = cpu_to_le32(cap->issue_seq);
msg->front.iov_len += sizeof(*item);
ceph_put_cap(mdsc, cap);
if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
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);
msg = NULL;
}
}
BUG_ON(num_cap_releases != 0);
spin_lock(&session->s_cap_lock);
}
if (!list_empty(&session->s_cap_releases))
goto again;
spin_unlock(&session->s_cap_lock);
if (msg) {
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);
}
static void discard_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_msg *msg;
struct ceph_mds_cap_release *head;
unsigned num;
dout("discard_cap_releases mds%d\n", session->s_mds);
if (!list_empty(&session->s_cap_releases)) {
/* zero out the in-progress message */
msg = list_first_entry(&session->s_cap_releases,
struct ceph_msg, list_head);
head = msg->front.iov_base;
num = le32_to_cpu(head->num);
dout("discard_cap_releases mds%d %p %u\n",
session->s_mds, msg, num);
head->num = cpu_to_le32(0);
msg->front.iov_len = sizeof(*head);
session->s_num_cap_releases += num;
}
/* requeue completed messages */
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);
head = msg->front.iov_base;
num = le32_to_cpu(head->num);
dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg,
num);
session->s_num_cap_releases += num;
head->num = cpu_to_le32(0);
msg->front.iov_len = sizeof(*head);
list_add(&msg->list_head, &session->s_cap_releases);
}
return;
out_err:
pr_err("send_cap_releases mds%d, failed to allocate message\n",
session->s_mds);
spin_lock(&session->s_cap_lock);
list_splice(&tmp_list, &session->s_cap_releases);
session->s_num_cap_releases += num_cap_releases;
spin_unlock(&session->s_cap_lock);
}
/*
@ -2529,7 +2481,6 @@ out_err:
}
mutex_unlock(&mdsc->mutex);
ceph_add_cap_releases(mdsc, req->r_session);
mutex_unlock(&session->s_mutex);
/* kick calling process */
@ -2921,8 +2872,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
*/
session->s_cap_reconnect = 1;
/* drop old cap expires; we're about to reestablish that state */
discard_cap_releases(mdsc, session);
spin_unlock(&session->s_cap_lock);
cleanup_cap_releases(mdsc, session);
/* trim unused caps to reduce MDS's cache rejoin time */
if (mdsc->fsc->sb->s_root)
@ -3385,7 +3335,6 @@ static void delayed_work(struct work_struct *work)
send_renew_caps(mdsc, s);
else
ceph_con_keepalive(&s->s_con);
ceph_add_cap_releases(mdsc, s);
if (s->s_state == CEPH_MDS_SESSION_OPEN ||
s->s_state == CEPH_MDS_SESSION_HUNG)
ceph_send_cap_releases(mdsc, s);

3
fs/ceph/mds_client.h
View File

@ -139,7 +139,6 @@ struct ceph_mds_session {
int s_cap_reconnect;
int s_readonly;
struct list_head s_cap_releases; /* waiting cap_release messages */
struct list_head s_cap_releases_done; /* ready to send */
struct ceph_cap *s_cap_iterator;
/* protected by mutex */
@ -389,8 +388,6 @@ static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
kref_put(&req->r_kref, ceph_mdsc_release_request);
}
extern int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session);
extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session);

18
fs/ceph/super.h
View File

@ -122,11 +122,21 @@ struct ceph_cap {
struct rb_node ci_node; /* per-ci cap tree */
struct ceph_mds_session *session;
struct list_head session_caps; /* per-session caplist */
int mds;
u64 cap_id; /* unique cap id (mds provided) */
union {
/* in-use caps */
struct {
int issued; /* latest, from the mds */
int implemented; /* implemented superset of issued (for revocation) */
int mds_wanted;
int implemented; /* implemented superset of
issued (for revocation) */
int mds, mds_wanted;
};
/* caps to release */
struct {
u64 cap_ino;
int queue_release;
};
};
u32 seq, issue_seq, mseq;
u32 cap_gen; /* active/stale cycle */
unsigned long last_used;
@ -845,8 +855,6 @@ extern void ceph_put_cap(struct ceph_mds_client *mdsc,
struct ceph_cap *cap);
extern int ceph_is_any_caps(struct inode *inode);
extern void __queue_cap_release(struct ceph_mds_session *session, u64 ino,
u64 cap_id, u32 migrate_seq, u32 issue_seq);
extern void ceph_queue_caps_release(struct inode *inode);
extern int ceph_write_inode(struct inode *inode, struct writeback_control *wbc);
extern int ceph_fsync(struct file *file, loff_t start, loff_t end,