mds_client.c 87.2 KB
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#include <linux/ceph/ceph_debug.h>
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#include <linux/fs.h>
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#include <linux/wait.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/debugfs.h>
#include <linux/seq_file.h>
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#include "super.h"
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#include "mds_client.h"

#include <linux/ceph/messenger.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/pagelist.h>
#include <linux/ceph/auth.h>
#include <linux/ceph/debugfs.h>
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/*
 * 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 * are no longer valid.
 */

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struct ceph_reconnect_state {
	struct ceph_pagelist *pagelist;
	bool flock;
};

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static void __wake_requests(struct ceph_mds_client *mdsc,
			    struct list_head *head);

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static const struct ceph_connection_operations mds_con_ops;
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/*
 * mds reply parsing
 */

/*
 * parse individual inode info
 */
static int parse_reply_info_in(void **p, void *end,
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			       struct ceph_mds_reply_info_in *info,
			       int features)
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{
	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;

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	if (features & CEPH_FEATURE_DIRLAYOUTHASH)
		ceph_decode_copy_safe(p, end, &info->dir_layout,
				      sizeof(info->dir_layout), bad);
	else
		memset(&info->dir_layout, 0, sizeof(info->dir_layout));

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	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,
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				  struct ceph_mds_reply_info_parsed *info,
				  int features)
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{
	int err;

	if (info->head->is_dentry) {
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		err = parse_reply_info_in(p, end, &info->diri, features);
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		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) {
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		err = parse_reply_info_in(p, end, &info->targeti, features);
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		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,
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				struct ceph_mds_reply_info_parsed *info,
				int features)
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{
	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);
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	num = ceph_decode_32(p);
	info->dir_end = ceph_decode_8(p);
	info->dir_complete = ceph_decode_8(p);
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	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);
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		info->dir_dname_len[i] = ceph_decode_32(p);
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		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 */
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		err = parse_reply_info_in(p, end, &info->dir_in[i], features);
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		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;
}

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/*
 * parse fcntl F_GETLK results
 */
static int parse_reply_info_filelock(void **p, void *end,
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				     struct ceph_mds_reply_info_parsed *info,
				     int features)
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{
	if (*p + sizeof(*info->filelock_reply) > end)
		goto bad;

	info->filelock_reply = *p;
	*p += sizeof(*info->filelock_reply);

	if (unlikely(*p != end))
		goto bad;
	return 0;

bad:
	return -EIO;
}

/*
 * parse extra results
 */
static int parse_reply_info_extra(void **p, void *end,
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				  struct ceph_mds_reply_info_parsed *info,
				  int features)
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{
	if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
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		return parse_reply_info_filelock(p, end, info, features);
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	else
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		return parse_reply_info_dir(p, end, info, features);
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}

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/*
 * parse entire mds reply
 */
static int parse_reply_info(struct ceph_msg *msg,
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			    struct ceph_mds_reply_info_parsed *info,
			    int features)
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{
	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) {
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		ceph_decode_need(&p, end, len, bad);
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		err = parse_reply_info_trace(&p, p+len, info, features);
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		if (err < 0)
			goto out_bad;
	}

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	/* extra */
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	ceph_decode_32_safe(&p, end, len, bad);
	if (len > 0) {
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		ceph_decode_need(&p, end, len, bad);
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		err = parse_reply_info_extra(&p, p+len, info, features);
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		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";
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	case CEPH_MDS_SESSION_RESTARTING: return "restarting";
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	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);
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	if (atomic_dec_and_test(&s->s_ref)) {
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		if (s->s_auth.authorizer)
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		     s->s_mdsc->fsc->client->monc.auth->ops->destroy_authorizer(
			     s->s_mdsc->fsc->client->monc.auth,
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			     s->s_auth.authorizer);
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		kfree(s);
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	}
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}

/*
 * 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];
}

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static int __verify_registered_session(struct ceph_mds_client *mdsc,
				       struct ceph_mds_session *s)
{
	if (s->s_mds >= mdsc->max_sessions ||
	    mdsc->sessions[s->s_mds] != s)
		return -ENOENT;
	return 0;
}

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/*
 * 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);
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	if (!s)
		return ERR_PTR(-ENOMEM);
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	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);

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	ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
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	spin_lock_init(&s->s_gen_ttl_lock);
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	s->s_cap_gen = 0;
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	s->s_cap_ttl = jiffies - 1;
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	spin_lock_init(&s->s_cap_lock);
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	s->s_renew_requested = 0;
	s->s_renew_seq = 0;
	INIT_LIST_HEAD(&s->s_caps);
	s->s_nr_caps = 0;
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	s->s_trim_caps = 0;
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	atomic_set(&s->s_ref, 1);
	INIT_LIST_HEAD(&s->s_waiting);
	INIT_LIST_HEAD(&s->s_unsafe);
	s->s_num_cap_releases = 0;
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	s->s_cap_iterator = NULL;
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	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)
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			goto fail_realloc;
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		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 */
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	ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
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	return s;
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fail_realloc:
	kfree(s);
	return ERR_PTR(-ENOMEM);
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}

/*
 * called under mdsc->mutex
 */
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static void __unregister_session(struct ceph_mds_client *mdsc,
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			       struct ceph_mds_session *s)
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{
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	dout("__unregister_session mds%d %p\n", s->s_mds, s);
	BUG_ON(mdsc->sessions[s->s_mds] != s);
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	mdsc->sessions[s->s_mds] = NULL;
	ceph_con_close(&s->s_con);
	ceph_put_mds_session(s);
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}

/*
 * 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;
	}
}

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void ceph_mdsc_release_request(struct kref *kref)
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{
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	struct ceph_mds_request *req = container_of(kref,
						    struct ceph_mds_request,
						    r_kref);
	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) {
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		ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
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		iput(req->r_inode);
	}
	if (req->r_locked_dir)
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		ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
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	if (req->r_target_inode)
		iput(req->r_target_inode);
	if (req->r_dentry)
		dput(req->r_dentry);
	if (req->r_old_dentry) {
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		/*
		 * track (and drop pins for) r_old_dentry_dir
		 * separately, since r_old_dentry's d_parent may have
		 * changed between the dir mutex being dropped and
		 * this request being freed.
		 */
		ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
				  CEPH_CAP_PIN);
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		dput(req->r_old_dentry);
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		iput(req->r_old_dentry_dir);
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	}
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	kfree(req->r_path1);
	kfree(req->r_path2);
	put_request_session(req);
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	ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
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	kfree(req);
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}

/*
 * 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;
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	struct rb_node *n = mdsc->request_tree.rb_node;

	while (n) {
		req = rb_entry(n, struct ceph_mds_request, r_node);
		if (tid < req->r_tid)
			n = n->rb_left;
		else if (tid > req->r_tid)
			n = n->rb_right;
		else {
			ceph_mdsc_get_request(req);
			return req;
		}
	}
	return NULL;
}

static void __insert_request(struct ceph_mds_client *mdsc,
			     struct ceph_mds_request *new)
{
	struct rb_node **p = &mdsc->request_tree.rb_node;
	struct rb_node *parent = NULL;
	struct ceph_mds_request *req = NULL;

	while (*p) {
		parent = *p;
		req = rb_entry(parent, struct ceph_mds_request, r_node);
		if (new->r_tid < req->r_tid)
			p = &(*p)->rb_left;
		else if (new->r_tid > req->r_tid)
			p = &(*p)->rb_right;
		else
			BUG();
	}

	rb_link_node(&new->r_node, parent, p);
	rb_insert_color(&new->r_node, &mdsc->request_tree);
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}

/*
 * 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)
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		ceph_reserve_caps(mdsc, &req->r_caps_reservation,
				  req->r_num_caps);
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	dout("__register_request %p tid %lld\n", req, req->r_tid);
	ceph_mdsc_get_request(req);
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	__insert_request(mdsc, req);
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	req->r_uid = current_fsuid();
	req->r_gid = current_fsgid();

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	if (dir) {
		struct ceph_inode_info *ci = ceph_inode(dir);

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		ihold(dir);
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		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);
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	rb_erase(&req->r_node, &mdsc->request_tree);
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	RB_CLEAR_NODE(&req->r_node);
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	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);
607 608 609

		iput(req->r_unsafe_dir);
		req->r_unsafe_dir = NULL;
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610
	}
611 612

	ceph_mdsc_put_request(req);
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613 614 615 616 617 618 619 620 621 622
}

/*
 * 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.
 */
623
static struct dentry *get_nonsnap_parent(struct dentry *dentry)
624
{
625 626 627 628 629 630
	/*
	 * we don't need to worry about protecting the d_parent access
	 * here because we never renaming inside the snapped namespace
	 * except to resplice to another snapdir, and either the old or new
	 * result is a valid result.
	 */
631 632 633 634 635
	while (!IS_ROOT(dentry) && ceph_snap(dentry->d_inode) != CEPH_NOSNAP)
		dentry = dentry->d_parent;
	return dentry;
}

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636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665
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) {
666 667 668
		/* ignore race with rename; old or new d_parent is okay */
		struct dentry *parent = req->r_dentry->d_parent;
		struct inode *dir = parent->d_inode;
669

670
		if (dir->i_sb != mdsc->fsc->sb) {
671 672 673 674 675
			/* not this fs! */
			inode = req->r_dentry->d_inode;
		} else if (ceph_snap(dir) != CEPH_NOSNAP) {
			/* direct snapped/virtual snapdir requests
			 * based on parent dir inode */
676
			struct dentry *dn = get_nonsnap_parent(parent);
677 678 679 680
			inode = dn->d_inode;
			dout("__choose_mds using nonsnap parent %p\n", inode);
		} else if (req->r_dentry->d_inode) {
			/* dentry target */
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681 682
			inode = req->r_dentry->d_inode;
		} else {
683 684
			/* dir + name */
			inode = dir;
685
			hash = ceph_dentry_hash(dir, req->r_dentry);
S
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686 687 688
			is_hash = true;
		}
	}
689

S
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690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711
	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),
712
				     frag.frag, mds,
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				     (int)r, frag.ndist);
714 715 716
				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
				    CEPH_MDS_STATE_ACTIVE)
					return mds;
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			}

			/* 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);
729 730 731
				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
				    CEPH_MDS_STATE_ACTIVE)
					return mds;
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732 733 734 735
			}
		}
	}

736
	spin_lock(&ci->i_ceph_lock);
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737 738 739 740 741 742
	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) {
743
		spin_unlock(&ci->i_ceph_lock);
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744 745 746 747 748 749
		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);
750
	spin_unlock(&ci->i_ceph_lock);
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751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767
	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;

768 769
	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
			   false);
770
	if (!msg) {
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		pr_err("create_session_msg ENOMEM creating msg\n");
772
		return NULL;
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773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800
	}
	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;

	/* 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);
801 802
	if (!msg)
		return -ENOMEM;
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	ceph_con_send(&session->s_con, msg);
	return 0;
}

807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843
/*
 * open sessions for any export targets for the given mds
 *
 * called under mdsc->mutex
 */
static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
					  struct ceph_mds_session *session)
{
	struct ceph_mds_info *mi;
	struct ceph_mds_session *ts;
	int i, mds = session->s_mds;
	int target;

	if (mds >= mdsc->mdsmap->m_max_mds)
		return;
	mi = &mdsc->mdsmap->m_info[mds];
	dout("open_export_target_sessions for mds%d (%d targets)\n",
	     session->s_mds, mi->num_export_targets);

	for (i = 0; i < mi->num_export_targets; i++) {
		target = mi->export_targets[i];
		ts = __ceph_lookup_mds_session(mdsc, target);
		if (!ts) {
			ts = register_session(mdsc, target);
			if (IS_ERR(ts))
				return;
		}
		if (session->s_state == CEPH_MDS_SESSION_NEW ||
		    session->s_state == CEPH_MDS_SESSION_CLOSING)
			__open_session(mdsc, session);
		else
			dout(" mds%d target mds%d %p is %s\n", session->s_mds,
			     i, ts, session_state_name(ts->s_state));
		ceph_put_mds_session(ts);
	}
}

844 845 846 847 848 849 850 851
void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
					   struct ceph_mds_session *session)
{
	mutex_lock(&mdsc->mutex);
	__open_export_target_sessions(mdsc, session);
	mutex_unlock(&mdsc->mutex);
}

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852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879
/*
 * 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);
}

/*
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 * Helper to safely iterate over all caps associated with a session, with
 * special care taken to handle a racing __ceph_remove_cap().
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 *
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 * Caller must hold session s_mutex.
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 */
static int iterate_session_caps(struct ceph_mds_session *session,
				 int (*cb)(struct inode *, struct ceph_cap *,
					    void *), void *arg)
{
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	struct list_head *p;
	struct ceph_cap *cap;
	struct inode *inode, *last_inode = NULL;
	struct ceph_cap *old_cap = NULL;
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893 894 895 896
	int ret;

	dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
	spin_lock(&session->s_cap_lock);
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	p = session->s_caps.next;
	while (p != &session->s_caps) {
		cap = list_entry(p, struct ceph_cap, session_caps);
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		inode = igrab(&cap->ci->vfs_inode);
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901 902
		if (!inode) {
			p = p->next;
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903
			continue;
S
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904 905
		}
		session->s_cap_iterator = cap;
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		spin_unlock(&session->s_cap_lock);
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907 908 909 910 911 912

		if (last_inode) {
			iput(last_inode);
			last_inode = NULL;
		}
		if (old_cap) {
913
			ceph_put_cap(session->s_mdsc, old_cap);
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			old_cap = NULL;
		}

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		ret = cb(inode, cap, arg);
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		last_inode = inode;

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		spin_lock(&session->s_cap_lock);
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921 922 923 924 925 926 927 928 929 930
		p = p->next;
		if (cap->ci == NULL) {
			dout("iterate_session_caps  finishing cap %p removal\n",
			     cap);
			BUG_ON(cap->session != session);
			list_del_init(&cap->session_caps);
			session->s_nr_caps--;
			cap->session = NULL;
			old_cap = cap;  /* put_cap it w/o locks held */
		}
931 932
		if (ret < 0)
			goto out;
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933
	}
934 935
	ret = 0;
out:
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936
	session->s_cap_iterator = NULL;
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937
	spin_unlock(&session->s_cap_lock);
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938 939 940 941

	if (last_inode)
		iput(last_inode);
	if (old_cap)
942
		ceph_put_cap(session->s_mdsc, old_cap);
S
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943

944
	return ret;
S
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945 946 947
}

static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
948
				  void *arg)
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949 950
{
	struct ceph_inode_info *ci = ceph_inode(inode);
951 952
	int drop = 0;

S
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953 954
	dout("removing cap %p, ci is %p, inode is %p\n",
	     cap, ci, &ci->vfs_inode);
955
	spin_lock(&ci->i_ceph_lock);
956 957 958
	__ceph_remove_cap(cap);
	if (!__ceph_is_any_real_caps(ci)) {
		struct ceph_mds_client *mdsc =
959
			ceph_sb_to_client(inode->i_sb)->mdsc;
960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987

		spin_lock(&mdsc->cap_dirty_lock);
		if (!list_empty(&ci->i_dirty_item)) {
			pr_info(" dropping dirty %s state for %p %lld\n",
				ceph_cap_string(ci->i_dirty_caps),
				inode, ceph_ino(inode));
			ci->i_dirty_caps = 0;
			list_del_init(&ci->i_dirty_item);
			drop = 1;
		}
		if (!list_empty(&ci->i_flushing_item)) {
			pr_info(" dropping dirty+flushing %s state for %p %lld\n",
				ceph_cap_string(ci->i_flushing_caps),
				inode, ceph_ino(inode));
			ci->i_flushing_caps = 0;
			list_del_init(&ci->i_flushing_item);
			mdsc->num_cap_flushing--;
			drop = 1;
		}
		if (drop && ci->i_wrbuffer_ref) {
			pr_info(" dropping dirty data for %p %lld\n",
				inode, ceph_ino(inode));
			ci->i_wrbuffer_ref = 0;
			ci->i_wrbuffer_ref_head = 0;
			drop++;
		}
		spin_unlock(&mdsc->cap_dirty_lock);
	}
988
	spin_unlock(&ci->i_ceph_lock);
989 990
	while (drop--)
		iput(inode);
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991 992 993 994 995 996 997 998 999 1000 1001
	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);
1002
	BUG_ON(!list_empty(&session->s_cap_flushing));
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1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014
	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)
{
1015 1016
	struct ceph_inode_info *ci = ceph_inode(inode);

1017
	wake_up_all(&ci->i_cap_wq);
1018
	if (arg) {
1019
		spin_lock(&ci->i_ceph_lock);
1020 1021
		ci->i_wanted_max_size = 0;
		ci->i_requested_max_size = 0;
1022
		spin_unlock(&ci->i_ceph_lock);
1023
	}
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1024 1025 1026
	return 0;
}

1027 1028
static void wake_up_session_caps(struct ceph_mds_session *session,
				 int reconnect)
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1029 1030
{
	dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1031 1032
	iterate_session_caps(session, wake_up_session_cb,
			     (void *)(unsigned long)reconnect);
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1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
}

/*
 * 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);
1050
	session->s_renew_requested = jiffies;
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1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064

	/* 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));
	msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
				 ++session->s_renew_seq);
1065 1066
	if (!msg)
		return -ENOMEM;
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1067 1068 1069 1070 1071 1072
	ceph_con_send(&session->s_con, msg);
	return 0;
}

/*
 * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1073 1074
 *
 * Called under session->s_mutex
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1075 1076 1077 1078 1079 1080 1081 1082
 */
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);
A
Alex Elder 已提交
1083
	was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
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1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101

	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)
1102
		wake_up_session_caps(session, 0);
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1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116
}

/*
 * send a session close request
 */
static int request_close_session(struct ceph_mds_client *mdsc,
				 struct ceph_mds_session *session)
{
	struct ceph_msg *msg;

	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);
1117 1118 1119 1120
	if (!msg)
		return -ENOMEM;
	ceph_con_send(&session->s_con, msg);
	return 0;
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1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153
}

/*
 * 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;

1154
	spin_lock(&ci->i_ceph_lock);
S
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1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169
	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 */
S
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1170
		__ceph_remove_cap(cap);
S
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1171 1172
	} else {
		/* try to drop referring dentries */
1173
		spin_unlock(&ci->i_ceph_lock);
S
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1174 1175 1176 1177 1178 1179 1180
		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:
1181
	spin_unlock(&ci->i_ceph_lock);
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1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
	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);
1202
		session->s_trim_caps = 0;
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1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
	}
	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.
 */
1214
int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
S
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1215
			  struct ceph_mds_session *session)
S
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1216
{
S
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1217
	struct ceph_msg *msg, *partial = NULL;
S
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1218 1219
	struct ceph_mds_cap_release *head;
	int err = -ENOMEM;
1220
	int extra = mdsc->fsc->mount_options->cap_release_safety;
S
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1221
	int num;
S
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1222

S
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1223 1224
	dout("add_cap_releases %p mds%d extra %d\n", session, session->s_mds,
	     extra);
S
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1225 1226 1227 1228 1229 1230 1231 1232

	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;
S
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1233 1234 1235 1236 1237 1238 1239
		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;
		}
S
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1240 1241 1242
	}
	while (session->s_num_cap_releases < session->s_nr_caps + extra) {
		spin_unlock(&session->s_cap_lock);
1243
		msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE,
1244
				   GFP_NOFS, false);
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1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256
		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;
	}

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1257 1258 1259 1260 1261 1262 1263 1264
	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;
S
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1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298
	}
	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;

1299
			spin_lock(&ci->i_ceph_lock);
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1300 1301 1302 1303 1304 1305 1306
			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;
			}
1307
			spin_unlock(&ci->i_ceph_lock);
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1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324
		}
		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
 */
1325 1326
void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
			    struct ceph_mds_session *session)
S
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1327 1328 1329 1330
{
	struct ceph_msg *msg;

	dout("send_cap_releases mds%d\n", session->s_mds);
1331 1332
	spin_lock(&session->s_cap_lock);
	while (!list_empty(&session->s_cap_releases_done)) {
S
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1333 1334 1335 1336 1337 1338 1339
		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);
1340
		spin_lock(&session->s_cap_lock);
S
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1341 1342 1343 1344
	}
	spin_unlock(&session->s_cap_lock);
}

1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382
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);
	spin_lock(&session->s_cap_lock);

	/* 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);
	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);
	}

	spin_unlock(&session->s_cap_lock);
}

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1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397
/*
 * 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);

1398
	mutex_init(&req->r_fill_mutex);
1399
	req->r_mdsc = mdsc;
S
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1400 1401 1402 1403
	req->r_started = jiffies;
	req->r_resend_mds = -1;
	INIT_LIST_HEAD(&req->r_unsafe_dir_item);
	req->r_fmode = -1;
1404
	kref_init(&req->r_kref);
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1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415
	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;
}

/*
S
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1416
 * return oldest (lowest) request, tid in request tree, 0 if none.
S
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1417 1418 1419
 *
 * called under mdsc->mutex.
 */
S
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1420 1421 1422 1423 1424 1425 1426 1427
static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
{
	if (RB_EMPTY_ROOT(&mdsc->request_tree))
		return NULL;
	return rb_entry(rb_first(&mdsc->request_tree),
			struct ceph_mds_request, r_node);
}

S
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1428 1429
static u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
{
S
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1430 1431 1432 1433 1434
	struct ceph_mds_request *req = __get_oldest_req(mdsc);

	if (req)
		return req->r_tid;
	return 0;
S
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1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452
}

/*
 * 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;
1453
	unsigned seq;
S
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1454 1455 1456 1457 1458 1459

	if (dentry == NULL)
		return ERR_PTR(-EINVAL);

retry:
	len = 0;
1460 1461
	seq = read_seqbegin(&rename_lock);
	rcu_read_lock();
S
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1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472
	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;
	}
1473
	rcu_read_unlock();
S
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1474 1475 1476 1477 1478 1479 1480 1481
	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 */
1482
	rcu_read_lock();
S
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1483
	for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1484
		struct inode *inode;
S
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1485

1486 1487
		spin_lock(&temp->d_lock);
		inode = temp->d_inode;
S
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1488
		if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
S
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1489
			dout("build_path path+%d: %p SNAPDIR\n",
S
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1490 1491 1492
			     pos, temp);
		} else if (stop_on_nosnap && inode &&
			   ceph_snap(inode) == CEPH_NOSNAP) {
1493
			spin_unlock(&temp->d_lock);
S
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1494 1495 1496
			break;
		} else {
			pos -= temp->d_name.len;
1497 1498
			if (pos < 0) {
				spin_unlock(&temp->d_lock);
S
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1499
				break;
1500
			}
S
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1501 1502 1503
			strncpy(path + pos, temp->d_name.name,
				temp->d_name.len);
		}
1504
		spin_unlock(&temp->d_lock);
S
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1505 1506 1507 1508
		if (pos)
			path[--pos] = '/';
		temp = temp->d_parent;
	}
1509 1510
	rcu_read_unlock();
	if (pos != 0 || read_seqretry(&rename_lock, seq)) {
S
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1511
		pr_err("build_path did not end path lookup where "
S
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1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522
		       "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;
S
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1523
	dout("build_path on %p %d built %llx '%.*s'\n",
N
Nick Piggin 已提交
1524
	     dentry, dentry->d_count, *base, len, path);
S
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1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588
	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);
1589
	} else if (rpath || rino) {
S
Sage Weil 已提交
1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634
		*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) +
1635
		pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64));
S
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1636 1637 1638 1639 1640 1641 1642 1643 1644 1645

	/* 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;

1646
	msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1647 1648
	if (!msg) {
		msg = ERR_PTR(-ENOMEM);
S
Sage Weil 已提交
1649
		goto out_free2;
1650
	}
S
Sage Weil 已提交
1651

1652 1653
	msg->hdr.tid = cpu_to_le64(req->r_tid);

S
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1654 1655 1656 1657 1658 1659
	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);
1660 1661
	head->caller_uid = cpu_to_le32(req->r_uid);
	head->caller_gid = cpu_to_le32(req->r_gid);
S
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1662 1663 1664 1665 1666
	head->args = req->r_args;

	ceph_encode_filepath(&p, end, ino1, path1);
	ceph_encode_filepath(&p, end, ino2, path2);

1667 1668 1669
	/* make note of release offset, in case we need to replay */
	req->r_request_release_offset = p - msg->front.iov_base;

S
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1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716
	/* 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
1717
		complete_all(&req->r_completion);
S
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1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731
}

/*
 * 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_attempts++;
1732 1733 1734 1735 1736 1737 1738 1739 1740
	if (req->r_inode) {
		struct ceph_cap *cap =
			ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);

		if (cap)
			req->r_sent_on_mseq = cap->mseq;
		else
			req->r_sent_on_mseq = -1;
	}
S
Sage Weil 已提交
1741 1742 1743
	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);

1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761
	if (req->r_got_unsafe) {
		/*
		 * Replay.  Do not regenerate message (and rebuild
		 * paths, etc.); just use the original message.
		 * Rebuilding paths will break for renames because
		 * d_move mangles the src name.
		 */
		msg = req->r_request;
		rhead = msg->front.iov_base;

		flags = le32_to_cpu(rhead->flags);
		flags |= CEPH_MDS_FLAG_REPLAY;
		rhead->flags = cpu_to_le32(flags);

		if (req->r_target_inode)
			rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));

		rhead->num_retry = req->r_attempts - 1;
1762 1763 1764 1765 1766

		/* remove cap/dentry releases from message */
		rhead->num_releases = 0;
		msg->hdr.front_len = cpu_to_le32(req->r_request_release_offset);
		msg->front.iov_len = req->r_request_release_offset;
1767 1768 1769
		return 0;
	}

S
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1770 1771 1772 1773 1774 1775
	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)) {
1776
		req->r_err = PTR_ERR(msg);
S
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1777
		complete_request(mdsc, req);
1778
		return PTR_ERR(msg);
S
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1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790
	}
	req->r_request = msg;

	rhead = msg->front.iov_base;
	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;
1791
	rhead->ino = 0;
S
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1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806

	dout(" r_locked_dir = %p\n", req->r_locked_dir);
	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;

1807
	if (req->r_err || req->r_got_result)
S
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1808 1809 1810 1811 1812 1813 1814 1815 1816
		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;
	}

1817 1818
	put_request_session(req);

S
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1819 1820 1821 1822 1823 1824 1825 1826 1827 1828
	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);
1829
	if (!session) {
S
Sage Weil 已提交
1830
		session = register_session(mdsc, mds);
1831 1832 1833 1834 1835
		if (IS_ERR(session)) {
			err = PTR_ERR(session);
			goto finish;
		}
	}
1836 1837
	req->r_session = get_session(session);

S
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1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866
	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_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:
1867
	req->r_err = err;
S
Sage Weil 已提交
1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
	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
1888
 * resubmit their requests to a possibly different mds.
S
Sage Weil 已提交
1889
 */
1890
static void kick_requests(struct ceph_mds_client *mdsc, int mds)
S
Sage Weil 已提交
1891
{
S
Sage Weil 已提交
1892 1893
	struct ceph_mds_request *req;
	struct rb_node *p;
S
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1894 1895

	dout("kick_requests mds%d\n", mds);
S
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1896 1897 1898 1899 1900 1901 1902 1903
	for (p = rb_first(&mdsc->request_tree); p; p = rb_next(p)) {
		req = rb_entry(p, struct ceph_mds_request, r_node);
		if (req->r_got_unsafe)
			continue;
		if (req->r_session &&
		    req->r_session->s_mds == mds) {
			dout(" kicking tid %llu\n", req->r_tid);
			__do_request(mdsc, req);
S
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1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
		}
	}
}

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)
1936 1937
		ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
				  CEPH_CAP_PIN);
S
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1938 1939 1940 1941 1942 1943

	/* issue */
	mutex_lock(&mdsc->mutex);
	__register_request(mdsc, req, dir);
	__do_request(mdsc, req);

1944 1945 1946 1947 1948
	if (req->r_err) {
		err = req->r_err;
		__unregister_request(mdsc, req);
		dout("do_request early error %d\n", err);
		goto out;
S
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1949 1950
	}

1951 1952 1953 1954
	/* wait */
	mutex_unlock(&mdsc->mutex);
	dout("do_request waiting\n");
	if (req->r_timeout) {
1955
		err = (long)wait_for_completion_killable_timeout(
1956 1957 1958 1959
			&req->r_completion, req->r_timeout);
		if (err == 0)
			err = -EIO;
	} else {
1960
		err = wait_for_completion_killable(&req->r_completion);
1961 1962 1963
	}
	dout("do_request waited, got %d\n", err);
	mutex_lock(&mdsc->mutex);
1964

1965 1966 1967 1968 1969
	/* only abort if we didn't race with a real reply */
	if (req->r_got_result) {
		err = le32_to_cpu(req->r_reply_info.head->result);
	} else if (err < 0) {
		dout("aborted request %lld with %d\n", req->r_tid, err);
1970 1971 1972 1973 1974 1975 1976

		/*
		 * ensure we aren't running concurrently with
		 * ceph_fill_trace or ceph_readdir_prepopulate, which
		 * rely on locks (dir mutex) held by our caller.
		 */
		mutex_lock(&req->r_fill_mutex);
1977 1978
		req->r_err = err;
		req->r_aborted = true;
1979
		mutex_unlock(&req->r_fill_mutex);
1980

1981
		if (req->r_locked_dir &&
1982 1983
		    (req->r_op & CEPH_MDS_OP_WRITE))
			ceph_invalidate_dir_request(req);
S
Sage Weil 已提交
1984
	} else {
1985
		err = req->r_err;
S
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1986 1987
	}

1988 1989
out:
	mutex_unlock(&mdsc->mutex);
S
Sage Weil 已提交
1990 1991 1992 1993
	dout("do_request %p done, result %d\n", req, err);
	return err;
}

1994
/*
S
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1995
 * Invalidate dir D_COMPLETE, dentry lease state on an aborted MDS
1996 1997 1998 1999 2000 2001 2002
 * namespace request.
 */
void ceph_invalidate_dir_request(struct ceph_mds_request *req)
{
	struct inode *inode = req->r_locked_dir;
	struct ceph_inode_info *ci = ceph_inode(inode);

S
Sage Weil 已提交
2003
	dout("invalidate_dir_request %p (D_COMPLETE, lease(s))\n", inode);
2004
	spin_lock(&ci->i_ceph_lock);
S
Sage Weil 已提交
2005
	ceph_dir_clear_complete(inode);
2006
	ci->i_release_count++;
2007
	spin_unlock(&ci->i_ceph_lock);
2008 2009 2010 2011 2012 2013 2014

	if (req->r_dentry)
		ceph_invalidate_dentry_lease(req->r_dentry);
	if (req->r_old_dentry)
		ceph_invalidate_dentry_lease(req->r_old_dentry);
}

S
Sage Weil 已提交
2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029
/*
 * 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;
2030
	int mds = session->s_mds;
S
Sage Weil 已提交
2031 2032 2033

	if (msg->front.iov_len < sizeof(*head)) {
		pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2034
		ceph_msg_dump(msg);
S
Sage Weil 已提交
2035 2036 2037 2038
		return;
	}

	/* get request, session */
2039
	tid = le64_to_cpu(msg->hdr.tid);
S
Sage Weil 已提交
2040 2041 2042 2043 2044 2045 2046 2047 2048 2049
	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);

	/* correct session? */
S
Sage Weil 已提交
2050
	if (req->r_session != session) {
S
Sage Weil 已提交
2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065
		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;
	}
2066 2067 2068 2069 2070 2071
	if (req->r_got_safe && !head->safe) {
		pr_warning("got unsafe after safe on %llu from mds%d\n",
			   tid, mds);
		mutex_unlock(&mdsc->mutex);
		goto out;
	}
S
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2072 2073 2074 2075

	result = le32_to_cpu(head->result);

	/*
2076 2077 2078 2079 2080
	 * Handle an ESTALE
	 * if we're not talking to the authority, send to them
	 * if the authority has changed while we weren't looking,
	 * send to new authority
	 * Otherwise we just have to return an ESTALE
S
Sage Weil 已提交
2081 2082
	 */
	if (result == -ESTALE) {
2083
		dout("got ESTALE on request %llu", req->r_tid);
S
Sage Weil 已提交
2084 2085 2086
		if (!req->r_inode) {
			/* do nothing; not an authority problem */
		} else if (req->r_direct_mode != USE_AUTH_MDS) {
2087 2088
			dout("not using auth, setting for that now");
			req->r_direct_mode = USE_AUTH_MDS;
S
Sage Weil 已提交
2089 2090 2091
			__do_request(mdsc, req);
			mutex_unlock(&mdsc->mutex);
			goto out;
2092 2093
		} else  {
			struct ceph_inode_info *ci = ceph_inode(req->r_inode);
S
Sage Weil 已提交
2094 2095 2096 2097 2098
			struct ceph_cap *cap = NULL;

			if (req->r_session)
				cap = ceph_get_cap_for_mds(ci,
						   req->r_session->s_mds);
2099 2100 2101 2102 2103 2104 2105 2106 2107

			dout("already using auth");
			if ((!cap || cap != ci->i_auth_cap) ||
			    (cap->mseq != req->r_sent_on_mseq)) {
				dout("but cap changed, so resending");
				__do_request(mdsc, req);
				mutex_unlock(&mdsc->mutex);
				goto out;
			}
S
Sage Weil 已提交
2108
		}
2109
		dout("have to return ESTALE on request %llu", req->r_tid);
S
Sage Weil 已提交
2110 2111
	}

2112

S
Sage Weil 已提交
2113 2114 2115
	if (head->safe) {
		req->r_got_safe = true;
		__unregister_request(mdsc, req);
2116
		complete_all(&req->r_safe_completion);
S
Sage Weil 已提交
2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129

		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? */
S
Sage Weil 已提交
2130
			if (mdsc->stopping && !__get_oldest_req(mdsc))
2131
				complete_all(&mdsc->safe_umount_waiters);
S
Sage Weil 已提交
2132 2133 2134
			mutex_unlock(&mdsc->mutex);
			goto out;
		}
2135
	} else {
S
Sage Weil 已提交
2136 2137 2138 2139 2140 2141
		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;
2142
	err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
S
Sage Weil 已提交
2143 2144 2145 2146
	mutex_unlock(&mdsc->mutex);

	mutex_lock(&session->s_mutex);
	if (err < 0) {
2147
		pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2148
		ceph_msg_dump(msg);
S
Sage Weil 已提交
2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163
		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 */
2164
	mutex_lock(&req->r_fill_mutex);
2165
	err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
S
Sage Weil 已提交
2166
	if (err == 0) {
2167 2168
		if (result == 0 && req->r_op != CEPH_MDS_OP_GETFILELOCK &&
		    rinfo->dir_nr)
S
Sage Weil 已提交
2169
			ceph_readdir_prepopulate(req, req->r_session);
2170
		ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
S
Sage Weil 已提交
2171
	}
2172
	mutex_unlock(&req->r_fill_mutex);
S
Sage Weil 已提交
2173 2174 2175

	up_read(&mdsc->snap_rwsem);
out_err:
2176 2177 2178 2179 2180 2181 2182 2183 2184
	mutex_lock(&mdsc->mutex);
	if (!req->r_aborted) {
		if (err) {
			req->r_err = err;
		} else {
			req->r_reply = msg;
			ceph_msg_get(msg);
			req->r_got_result = true;
		}
S
Sage Weil 已提交
2185
	} else {
2186
		dout("reply arrived after request %lld was aborted\n", tid);
S
Sage Weil 已提交
2187
	}
2188
	mutex_unlock(&mdsc->mutex);
S
Sage Weil 已提交
2189

S
Sage Weil 已提交
2190
	ceph_add_cap_releases(mdsc, req->r_session);
S
Sage Weil 已提交
2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204
	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.
 */
2205 2206 2207
static void handle_forward(struct ceph_mds_client *mdsc,
			   struct ceph_mds_session *session,
			   struct ceph_msg *msg)
S
Sage Weil 已提交
2208 2209
{
	struct ceph_mds_request *req;
2210
	u64 tid = le64_to_cpu(msg->hdr.tid);
S
Sage Weil 已提交
2211 2212 2213 2214 2215 2216
	u32 next_mds;
	u32 fwd_seq;
	int err = -EINVAL;
	void *p = msg->front.iov_base;
	void *end = p + msg->front.iov_len;

2217
	ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2218 2219
	next_mds = ceph_decode_32(&p);
	fwd_seq = ceph_decode_32(&p);
S
Sage Weil 已提交
2220 2221 2222 2223

	mutex_lock(&mdsc->mutex);
	req = __lookup_request(mdsc, tid);
	if (!req) {
2224
		dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
S
Sage Weil 已提交
2225 2226 2227
		goto out;  /* dup reply? */
	}

2228 2229 2230 2231 2232
	if (req->r_aborted) {
		dout("forward tid %llu aborted, unregistering\n", tid);
		__unregister_request(mdsc, req);
	} else if (fwd_seq <= req->r_num_fwd) {
		dout("forward tid %llu to mds%d - old seq %d <= %d\n",
S
Sage Weil 已提交
2233 2234 2235
		     tid, next_mds, req->r_num_fwd, fwd_seq);
	} else {
		/* resend. forward race not possible; mds would drop */
2236 2237 2238
		dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
		BUG_ON(req->r_err);
		BUG_ON(req->r_got_result);
S
Sage Weil 已提交
2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261
		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;
2262
	int mds = session->s_mds;
S
Sage Weil 已提交
2263 2264 2265 2266 2267 2268 2269 2270 2271 2272
	struct ceph_mds_session_head *h = msg->front.iov_base;
	int wake = 0;

	/* 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);
2273 2274
	if (op == CEPH_SESSION_CLOSE)
		__unregister_session(mdsc, session);
S
Sage Weil 已提交
2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291
	/* 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:
2292 2293
		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
			pr_info("mds%d reconnect success\n", session->s_mds);
S
Sage Weil 已提交
2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306
		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:
2307 2308
		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
			pr_info("mds%d reconnect denied\n", session->s_mds);
S
Sage Weil 已提交
2309 2310
		remove_session_caps(session);
		wake = 1; /* for good measure */
2311
		wake_up_all(&mdsc->session_close_wq);
2312
		kick_requests(mdsc, mds);
S
Sage Weil 已提交
2313 2314 2315 2316 2317
		break;

	case CEPH_SESSION_STALE:
		pr_info("mds%d caps went stale, renewing\n",
			session->s_mds);
2318
		spin_lock(&session->s_gen_ttl_lock);
S
Sage Weil 已提交
2319
		session->s_cap_gen++;
A
Alex Elder 已提交
2320
		session->s_cap_ttl = jiffies - 1;
2321
		spin_unlock(&session->s_gen_ttl_lock);
S
Sage Weil 已提交
2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344
		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);
2345
	ceph_msg_dump(msg);
S
Sage Weil 已提交
2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377
	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.
 */
static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
			  void *arg)
{
S
Sage Weil 已提交
2378 2379 2380 2381 2382
	union {
		struct ceph_mds_cap_reconnect v2;
		struct ceph_mds_cap_reconnect_v1 v1;
	} rec;
	size_t reclen;
S
Sage Weil 已提交
2383
	struct ceph_inode_info *ci;
S
Sage Weil 已提交
2384 2385
	struct ceph_reconnect_state *recon_state = arg;
	struct ceph_pagelist *pagelist = recon_state->pagelist;
S
Sage Weil 已提交
2386 2387 2388 2389 2390 2391 2392 2393 2394 2395
	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));
2396 2397 2398
	err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
	if (err)
		return err;
S
Sage Weil 已提交
2399 2400 2401 2402 2403 2404

	dentry = d_find_alias(inode);
	if (dentry) {
		path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
		if (IS_ERR(path)) {
			err = PTR_ERR(path);
2405
			goto out_dput;
S
Sage Weil 已提交
2406 2407 2408 2409 2410
		}
	} else {
		path = NULL;
		pathlen = 0;
	}
2411 2412
	err = ceph_pagelist_encode_string(pagelist, path, pathlen);
	if (err)
2413
		goto out_free;
S
Sage Weil 已提交
2414

2415
	spin_lock(&ci->i_ceph_lock);
S
Sage Weil 已提交
2416 2417
	cap->seq = 0;        /* reset cap seq */
	cap->issue_seq = 0;  /* and issue_seq */
S
Sage Weil 已提交
2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437

	if (recon_state->flock) {
		rec.v2.cap_id = cpu_to_le64(cap->cap_id);
		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.flock_len = 0;
		reclen = sizeof(rec.v2);
	} else {
		rec.v1.cap_id = cpu_to_le64(cap->cap_id);
		rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
		rec.v1.issued = cpu_to_le32(cap->issued);
		rec.v1.size = cpu_to_le64(inode->i_size);
		ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
		ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
		rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
		rec.v1.pathbase = cpu_to_le64(pathbase);
		reclen = sizeof(rec.v1);
	}
2438
	spin_unlock(&ci->i_ceph_lock);
S
Sage Weil 已提交
2439

G
Greg Farnum 已提交
2440 2441
	if (recon_state->flock) {
		int num_fcntl_locks, num_flock_locks;
2442 2443 2444 2445
		struct ceph_pagelist_cursor trunc_point;

		ceph_pagelist_set_cursor(pagelist, &trunc_point);
		do {
S
Sage Weil 已提交
2446
			lock_flocks();
2447 2448 2449 2450 2451
			ceph_count_locks(inode, &num_fcntl_locks,
					 &num_flock_locks);
			rec.v2.flock_len = (2*sizeof(u32) +
					    (num_fcntl_locks+num_flock_locks) *
					    sizeof(struct ceph_filelock));
S
Sage Weil 已提交
2452
			unlock_flocks();
2453 2454 2455 2456 2457 2458 2459 2460 2461 2462

			/* pre-alloc pagelist */
			ceph_pagelist_truncate(pagelist, &trunc_point);
			err = ceph_pagelist_append(pagelist, &rec, reclen);
			if (!err)
				err = ceph_pagelist_reserve(pagelist,
							    rec.v2.flock_len);

			/* encode locks */
			if (!err) {
S
Sage Weil 已提交
2463
				lock_flocks();
2464 2465 2466 2467
				err = ceph_encode_locks(inode,
							pagelist,
							num_fcntl_locks,
							num_flock_locks);
S
Sage Weil 已提交
2468
				unlock_flocks();
2469 2470
			}
		} while (err == -ENOSPC);
2471 2472
	} else {
		err = ceph_pagelist_append(pagelist, &rec, reclen);
G
Greg Farnum 已提交
2473
	}
2474

2475
out_free:
S
Sage Weil 已提交
2476
	kfree(path);
2477
out_dput:
S
Sage Weil 已提交
2478
	dput(dentry);
2479
	return err;
S
Sage Weil 已提交
2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494
}


/*
 * 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.
 */
2495 2496
static void send_mds_reconnect(struct ceph_mds_client *mdsc,
			       struct ceph_mds_session *session)
S
Sage Weil 已提交
2497 2498
{
	struct ceph_msg *reply;
S
Sage Weil 已提交
2499
	struct rb_node *p;
2500
	int mds = session->s_mds;
2501
	int err = -ENOMEM;
2502
	struct ceph_pagelist *pagelist;
S
Sage Weil 已提交
2503
	struct ceph_reconnect_state recon_state;
S
Sage Weil 已提交
2504

2505
	pr_info("mds%d reconnect start\n", mds);
S
Sage Weil 已提交
2506

2507 2508 2509 2510 2511
	pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
	if (!pagelist)
		goto fail_nopagelist;
	ceph_pagelist_init(pagelist);

2512
	reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2513
	if (!reply)
2514 2515
		goto fail_nomsg;

2516 2517 2518
	mutex_lock(&session->s_mutex);
	session->s_state = CEPH_MDS_SESSION_RECONNECTING;
	session->s_seq = 0;
S
Sage Weil 已提交
2519

2520
	ceph_con_open(&session->s_con,
2521
		      CEPH_ENTITY_TYPE_MDS, mds,
2522
		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
S
Sage Weil 已提交
2523

2524 2525
	/* replay unsafe requests */
	replay_unsafe_requests(mdsc, session);
S
Sage Weil 已提交
2526 2527 2528 2529 2530 2531

	down_read(&mdsc->snap_rwsem);

	dout("session %p state %s\n", session,
	     session_state_name(session->s_state));

2532 2533 2534
	/* drop old cap expires; we're about to reestablish that state */
	discard_cap_releases(mdsc, session);

S
Sage Weil 已提交
2535
	/* traverse this session's caps */
2536 2537 2538
	err = ceph_pagelist_encode_32(pagelist, session->s_nr_caps);
	if (err)
		goto fail;
S
Sage Weil 已提交
2539 2540 2541 2542

	recon_state.pagelist = pagelist;
	recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
	err = iterate_session_caps(session, encode_caps_cb, &recon_state);
S
Sage Weil 已提交
2543
	if (err < 0)
2544
		goto fail;
S
Sage Weil 已提交
2545 2546 2547 2548 2549 2550

	/*
	 * 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.
	 */
S
Sage Weil 已提交
2551 2552 2553
	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);
2554
		struct ceph_mds_snaprealm_reconnect sr_rec;
S
Sage Weil 已提交
2555 2556 2557

		dout(" adding snap realm %llx seq %lld parent %llx\n",
		     realm->ino, realm->seq, realm->parent_ino);
2558 2559 2560 2561 2562 2563
		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;
S
Sage Weil 已提交
2564 2565
	}

2566
	reply->pagelist = pagelist;
S
Sage Weil 已提交
2567 2568
	if (recon_state.flock)
		reply->hdr.version = cpu_to_le16(2);
2569 2570
	reply->hdr.data_len = cpu_to_le32(pagelist->length);
	reply->nr_pages = calc_pages_for(0, pagelist->length);
S
Sage Weil 已提交
2571 2572
	ceph_con_send(&session->s_con, reply);

2573 2574 2575 2576 2577 2578
	mutex_unlock(&session->s_mutex);

	mutex_lock(&mdsc->mutex);
	__wake_requests(mdsc, &session->s_waiting);
	mutex_unlock(&mdsc->mutex);

S
Sage Weil 已提交
2579 2580 2581
	up_read(&mdsc->snap_rwsem);
	return;

2582
fail:
S
Sage Weil 已提交
2583
	ceph_msg_put(reply);
2584 2585
	up_read(&mdsc->snap_rwsem);
	mutex_unlock(&session->s_mutex);
2586 2587 2588 2589
fail_nomsg:
	ceph_pagelist_release(pagelist);
	kfree(pagelist);
fail_nopagelist:
2590 2591
	pr_err("error %d preparing reconnect for mds%d\n", err, mds);
	return;
S
Sage Weil 已提交
2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618
}


/*
 * 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);

2619
		dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
S
Sage Weil 已提交
2620
		     i, ceph_mds_state_name(oldstate),
2621
		     ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
S
Sage Weil 已提交
2622
		     ceph_mds_state_name(newstate),
2623
		     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
S
Sage Weil 已提交
2624 2625 2626 2627 2628 2629 2630 2631 2632
		     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);
2633
				__unregister_session(mdsc, s);
S
Sage Weil 已提交
2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644
			} 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 */
2645
			kick_requests(mdsc, i);
S
Sage Weil 已提交
2646 2647 2648 2649 2650 2651 2652 2653
		} else if (oldstate == newstate) {
			continue;  /* nothing new with this mds */
		}

		/*
		 * send reconnect?
		 */
		if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
2654 2655 2656 2657 2658
		    newstate >= CEPH_MDS_STATE_RECONNECT) {
			mutex_unlock(&mdsc->mutex);
			send_mds_reconnect(mdsc, s);
			mutex_lock(&mdsc->mutex);
		}
S
Sage Weil 已提交
2659 2660

		/*
2661
		 * kick request on any mds that has gone active.
S
Sage Weil 已提交
2662 2663 2664
		 */
		if (oldstate < CEPH_MDS_STATE_ACTIVE &&
		    newstate >= CEPH_MDS_STATE_ACTIVE) {
2665 2666 2667 2668
			if (oldstate != CEPH_MDS_STATE_CREATING &&
			    oldstate != CEPH_MDS_STATE_STARTING)
				pr_info("mds%d recovery completed\n", s->s_mds);
			kick_requests(mdsc, i);
S
Sage Weil 已提交
2669
			ceph_kick_flushing_caps(mdsc, s);
2670
			wake_up_session_caps(s, 1);
S
Sage Weil 已提交
2671 2672
		}
	}
2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687

	for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
		s = mdsc->sessions[i];
		if (!s)
			continue;
		if (!ceph_mdsmap_is_laggy(newmap, i))
			continue;
		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
		    s->s_state == CEPH_MDS_SESSION_HUNG ||
		    s->s_state == CEPH_MDS_SESSION_CLOSING) {
			dout(" connecting to export targets of laggy mds%d\n",
			     i);
			__open_export_target_sessions(mdsc, s);
		}
	}
S
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2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706
}



/*
 * 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;
}

2707 2708 2709
static void handle_lease(struct ceph_mds_client *mdsc,
			 struct ceph_mds_session *session,
			 struct ceph_msg *msg)
S
Sage Weil 已提交
2710
{
2711
	struct super_block *sb = mdsc->fsc->sb;
S
Sage Weil 已提交
2712 2713 2714
	struct inode *inode;
	struct dentry *parent, *dentry;
	struct ceph_dentry_info *di;
2715
	int mds = session->s_mds;
S
Sage Weil 已提交
2716
	struct ceph_mds_lease *h = msg->front.iov_base;
2717
	u32 seq;
S
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2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728
	struct ceph_vino vino;
	struct qstr dname;
	int release = 0;

	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;
2729
	seq = le32_to_cpu(h->seq);
S
Sage Weil 已提交
2730 2731 2732 2733 2734 2735 2736 2737 2738 2739
	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;

	mutex_lock(&session->s_mutex);
	session->s_seq++;

	/* lookup inode */
	inode = ceph_find_inode(sb, vino);
S
Sage Weil 已提交
2740 2741
	dout("handle_lease %s, ino %llx %p %.*s\n",
	     ceph_lease_op_name(h->action), vino.ino, inode,
2742
	     dname.len, dname.name);
S
Sage Weil 已提交
2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764
	if (inode == NULL) {
		dout("handle_lease no inode %llx\n", vino.ino);
		goto release;
	}

	/* 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:
2765
		if (di->lease_session == session) {
2766 2767
			if (ceph_seq_cmp(di->lease_seq, seq) > 0)
				h->seq = cpu_to_le32(di->lease_seq);
S
Sage Weil 已提交
2768 2769 2770 2771 2772 2773
			__ceph_mdsc_drop_dentry_lease(dentry);
		}
		release = 1;
		break;

	case CEPH_MDS_LEASE_RENEW:
2774
		if (di->lease_session == session &&
S
Sage Weil 已提交
2775 2776 2777 2778 2779 2780
		    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;

2781
			di->lease_seq = seq;
S
Sage Weil 已提交
2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807
			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);
	return;

bad:
	pr_err("corrupt lease message\n");
2808
	ceph_msg_dump(msg);
S
Sage Weil 已提交
2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825
}

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;

2826
	msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
2827
	if (!msg)
S
Sage Weil 已提交
2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851
		return;
	lease = msg->front.iov_base;
	lease->action = action;
	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,
S
Sage Weil 已提交
2852
			     struct dentry *dentry)
S
Sage Weil 已提交
2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868
{
	struct ceph_dentry_info *di;
	struct ceph_mds_session *session;
	u32 seq;

	BUG_ON(inode == NULL);
	BUG_ON(dentry == NULL);

	/* 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 -- "
S
Sage Weil 已提交
2869 2870
		     "no lease\n",
		     inode, dentry);
S
Sage Weil 已提交
2871 2872 2873 2874 2875 2876 2877 2878 2879 2880
		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);

S
Sage Weil 已提交
2881 2882
	dout("lease_release inode %p dentry %p to mds%d\n",
	     inode, dentry, session->s_mds);
S
Sage Weil 已提交
2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930
	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");
2931
	ceph_check_delayed_caps(mdsc);
S
Sage Weil 已提交
2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968

	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);
S
Sage Weil 已提交
2969
		ceph_add_cap_releases(mdsc, s);
2970 2971
		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
		    s->s_state == CEPH_MDS_SESSION_HUNG)
2972
			ceph_send_cap_releases(mdsc, s);
S
Sage Weil 已提交
2973 2974 2975 2976 2977 2978 2979 2980 2981 2982
		mutex_unlock(&s->s_mutex);
		ceph_put_mds_session(s);

		mutex_lock(&mdsc->mutex);
	}
	mutex_unlock(&mdsc->mutex);

	schedule_delayed(mdsc);
}

2983
int ceph_mdsc_init(struct ceph_fs_client *fsc)
S
Sage Weil 已提交
2984 2985

{
2986 2987 2988 2989 2990 2991 2992
	struct ceph_mds_client *mdsc;

	mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
	if (!mdsc)
		return -ENOMEM;
	mdsc->fsc = fsc;
	fsc->mdsc = mdsc;
S
Sage Weil 已提交
2993 2994
	mutex_init(&mdsc->mutex);
	mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
C
Cheng Renquan 已提交
2995 2996 2997
	if (mdsc->mdsmap == NULL)
		return -ENOMEM;

S
Sage Weil 已提交
2998
	init_completion(&mdsc->safe_umount_waiters);
2999
	init_waitqueue_head(&mdsc->session_close_wq);
S
Sage Weil 已提交
3000 3001 3002 3003 3004
	INIT_LIST_HEAD(&mdsc->waiting_for_map);
	mdsc->sessions = NULL;
	mdsc->max_sessions = 0;
	mdsc->stopping = 0;
	init_rwsem(&mdsc->snap_rwsem);
S
Sage Weil 已提交
3005
	mdsc->snap_realms = RB_ROOT;
S
Sage Weil 已提交
3006 3007 3008
	INIT_LIST_HEAD(&mdsc->snap_empty);
	spin_lock_init(&mdsc->snap_empty_lock);
	mdsc->last_tid = 0;
S
Sage Weil 已提交
3009
	mdsc->request_tree = RB_ROOT;
S
Sage Weil 已提交
3010 3011 3012 3013 3014 3015 3016 3017
	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);
S
Sage Weil 已提交
3018
	INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
S
Sage Weil 已提交
3019 3020 3021 3022 3023
	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);
C
Cheng Renquan 已提交
3024

3025
	ceph_caps_init(mdsc);
3026
	ceph_adjust_min_caps(mdsc, fsc->min_caps);
3027

3028
	return 0;
S
Sage Weil 已提交
3029 3030 3031 3032 3033 3034 3035 3036 3037
}

/*
 * 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;
3038
	struct ceph_fs_client *fsc = mdsc->fsc;
S
Sage Weil 已提交
3039 3040

	mutex_lock(&mdsc->mutex);
S
Sage Weil 已提交
3041
	if (__get_oldest_req(mdsc)) {
S
Sage Weil 已提交
3042
		mutex_unlock(&mdsc->mutex);
S
Sage Weil 已提交
3043

S
Sage Weil 已提交
3044 3045
		dout("wait_requests waiting for requests\n");
		wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3046
				    fsc->client->options->mount_timeout * HZ);
S
Sage Weil 已提交
3047 3048

		/* tear down remaining requests */
S
Sage Weil 已提交
3049 3050
		mutex_lock(&mdsc->mutex);
		while ((req = __get_oldest_req(mdsc))) {
S
Sage Weil 已提交
3051 3052
			dout("wait_requests timed out on tid %llu\n",
			     req->r_tid);
S
Sage Weil 已提交
3053
			__unregister_request(mdsc, req);
S
Sage Weil 已提交
3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069
		}
	}
	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);
3070
	ceph_flush_dirty_caps(mdsc);
S
Sage Weil 已提交
3071
	wait_requests(mdsc);
3072 3073 3074 3075 3076 3077

	/*
	 * wait for reply handlers to drop their request refs and
	 * their inode/dcache refs
	 */
	ceph_msgr_flush();
S
Sage Weil 已提交
3078 3079 3080 3081 3082 3083 3084
}

/*
 * wait for all write mds requests to flush.
 */
static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
{
3085
	struct ceph_mds_request *req = NULL, *nextreq;
S
Sage Weil 已提交
3086
	struct rb_node *n;
S
Sage Weil 已提交
3087 3088 3089

	mutex_lock(&mdsc->mutex);
	dout("wait_unsafe_requests want %lld\n", want_tid);
3090
restart:
S
Sage Weil 已提交
3091 3092
	req = __get_oldest_req(mdsc);
	while (req && req->r_tid <= want_tid) {
3093 3094 3095 3096 3097 3098
		/* find next request */
		n = rb_next(&req->r_node);
		if (n)
			nextreq = rb_entry(n, struct ceph_mds_request, r_node);
		else
			nextreq = NULL;
S
Sage Weil 已提交
3099 3100 3101
		if ((req->r_op & CEPH_MDS_OP_WRITE)) {
			/* write op */
			ceph_mdsc_get_request(req);
3102 3103
			if (nextreq)
				ceph_mdsc_get_request(nextreq);
S
Sage Weil 已提交
3104 3105 3106 3107 3108 3109
			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);
3110 3111 3112 3113 3114 3115 3116 3117
			if (!nextreq)
				break;  /* next dne before, so we're done! */
			if (RB_EMPTY_NODE(&nextreq->r_node)) {
				/* next request was removed from tree */
				ceph_mdsc_put_request(nextreq);
				goto restart;
			}
			ceph_mdsc_put_request(nextreq);  /* won't go away */
S
Sage Weil 已提交
3118
		}
3119
		req = nextreq;
S
Sage Weil 已提交
3120 3121 3122 3123 3124 3125 3126 3127 3128
	}
	mutex_unlock(&mdsc->mutex);
	dout("wait_unsafe_requests done\n");
}

void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
{
	u64 want_tid, want_flush;

3129
	if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3130 3131
		return;

S
Sage Weil 已提交
3132 3133 3134 3135 3136 3137 3138
	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);

3139
	ceph_flush_dirty_caps(mdsc);
S
Sage Weil 已提交
3140 3141 3142 3143 3144

	wait_unsafe_requests(mdsc, want_tid);
	wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush));
}

3145 3146 3147
/*
 * true if all sessions are closed, or we force unmount
 */
3148
static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3149 3150 3151
{
	int i, n = 0;

3152
	if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3153 3154 3155 3156 3157 3158 3159 3160 3161
		return true;

	mutex_lock(&mdsc->mutex);
	for (i = 0; i < mdsc->max_sessions; i++)
		if (mdsc->sessions[i])
			n++;
	mutex_unlock(&mdsc->mutex);
	return n == 0;
}
S
Sage Weil 已提交
3162 3163 3164 3165 3166 3167 3168 3169

/*
 * called after sb is ro.
 */
void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
{
	struct ceph_mds_session *session;
	int i;
3170 3171
	struct ceph_fs_client *fsc = mdsc->fsc;
	unsigned long timeout = fsc->client->options->mount_timeout * HZ;
S
Sage Weil 已提交
3172 3173 3174 3175

	dout("close_sessions\n");

	/* close sessions */
3176 3177 3178 3179 3180
	mutex_lock(&mdsc->mutex);
	for (i = 0; i < mdsc->max_sessions; i++) {
		session = __ceph_lookup_mds_session(mdsc, i);
		if (!session)
			continue;
S
Sage Weil 已提交
3181
		mutex_unlock(&mdsc->mutex);
3182 3183 3184 3185
		mutex_lock(&session->s_mutex);
		__close_session(mdsc, session);
		mutex_unlock(&session->s_mutex);
		ceph_put_mds_session(session);
S
Sage Weil 已提交
3186 3187
		mutex_lock(&mdsc->mutex);
	}
3188 3189 3190 3191 3192
	mutex_unlock(&mdsc->mutex);

	dout("waiting for sessions to close\n");
	wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
			   timeout);
S
Sage Weil 已提交
3193 3194

	/* tear down remaining sessions */
3195
	mutex_lock(&mdsc->mutex);
S
Sage Weil 已提交
3196 3197 3198
	for (i = 0; i < mdsc->max_sessions; i++) {
		if (mdsc->sessions[i]) {
			session = get_session(mdsc->sessions[i]);
3199
			__unregister_session(mdsc, session);
S
Sage Weil 已提交
3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217
			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");
}

3218
static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
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3219 3220 3221 3222 3223 3224
{
	dout("stop\n");
	cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
	if (mdsc->mdsmap)
		ceph_mdsmap_destroy(mdsc->mdsmap);
	kfree(mdsc->sessions);
3225
	ceph_caps_finalize(mdsc);
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3226 3227
}

3228 3229 3230 3231
void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
{
	struct ceph_mds_client *mdsc = fsc->mdsc;

3232
	dout("mdsc_destroy %p\n", mdsc);
3233
	ceph_mdsc_stop(mdsc);
3234 3235 3236 3237

	/* flush out any connection work with references to us */
	ceph_msgr_flush();

3238 3239
	fsc->mdsc = NULL;
	kfree(mdsc);
3240
	dout("mdsc_destroy %p done\n", mdsc);
3241 3242
}

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3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258

/*
 * 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));
3259
	if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3260
		return;
3261 3262
	epoch = ceph_decode_32(&p);
	maplen = ceph_decode_32(&p);
S
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3263 3264 3265
	dout("handle_map epoch %u len %d\n", epoch, (int)maplen);

	/* do we need it? */
3266
	ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
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3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289
	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 */
	}
3290
	mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
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	__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)) {
3310
		dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
S
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3311 3312 3313 3314 3315 3316 3317 3318 3319 3320
		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;

3321
	dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
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3322 3323 3324 3325 3326 3327 3328 3329 3330 3331
	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;
3332
	struct ceph_mds_client *mdsc = s->s_mdsc;
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3333

3334 3335
	pr_warning("mds%d closed our session\n", s->s_mds);
	send_mds_reconnect(mdsc, s);
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3336 3337 3338 3339 3340 3341 3342 3343
}

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);

3344 3345 3346 3347 3348 3349 3350
	mutex_lock(&mdsc->mutex);
	if (__verify_registered_session(mdsc, s) < 0) {
		mutex_unlock(&mdsc->mutex);
		goto out;
	}
	mutex_unlock(&mdsc->mutex);

S
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3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361
	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:
3362
		handle_forward(mdsc, s, msg);
S
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3363 3364 3365 3366 3367
		break;
	case CEPH_MSG_CLIENT_CAPS:
		ceph_handle_caps(s, msg);
		break;
	case CEPH_MSG_CLIENT_SNAP:
3368
		ceph_handle_snap(mdsc, s, msg);
S
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3369 3370
		break;
	case CEPH_MSG_CLIENT_LEASE:
3371
		handle_lease(mdsc, s, msg);
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3372 3373 3374 3375 3376 3377
		break;

	default:
		pr_err("received unknown message type %d %s\n", type,
		       ceph_msg_type_name(type));
	}
3378
out:
S
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3379 3380 3381
	ceph_msg_put(msg);
}

3382 3383 3384
/*
 * authentication
 */
3385 3386 3387 3388 3389 3390

/*
 * Note: returned pointer is the address of a structure that's
 * managed separately.  Caller must *not* attempt to free it.
 */
static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3391
					int *proto, int force_new)
3392 3393 3394
{
	struct ceph_mds_session *s = con->private;
	struct ceph_mds_client *mdsc = s->s_mdsc;
3395
	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3396
	struct ceph_auth_handshake *auth = &s->s_auth;
3397

3398
	if (force_new && auth->authorizer) {
3399 3400
		if (ac->ops && ac->ops->destroy_authorizer)
			ac->ops->destroy_authorizer(ac, auth->authorizer);
3401
		auth->authorizer = NULL;
3402
	}
3403
	if (!auth->authorizer && ac->ops && ac->ops->create_authorizer) {
3404 3405
		int ret = ac->ops->create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
							auth);
3406
		if (ret)
3407
			return ERR_PTR(ret);
3408 3409
	}
	*proto = ac->protocol;
3410

3411
	return auth;
3412 3413 3414 3415 3416 3417 3418
}


static int verify_authorizer_reply(struct ceph_connection *con, int len)
{
	struct ceph_mds_session *s = con->private;
	struct ceph_mds_client *mdsc = s->s_mdsc;
3419
	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3420

3421
	return ac->ops->verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3422 3423
}

3424 3425 3426 3427
static int invalidate_authorizer(struct ceph_connection *con)
{
	struct ceph_mds_session *s = con->private;
	struct ceph_mds_client *mdsc = s->s_mdsc;
3428
	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3429 3430 3431 3432

	if (ac->ops->invalidate_authorizer)
		ac->ops->invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);

3433
	return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3434 3435
}

3436
static const struct ceph_connection_operations mds_con_ops = {
S
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3437 3438 3439
	.get = con_get,
	.put = con_put,
	.dispatch = dispatch,
3440 3441
	.get_authorizer = get_authorizer,
	.verify_authorizer_reply = verify_authorizer_reply,
3442
	.invalidate_authorizer = invalidate_authorizer,
S
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3443 3444 3445 3446
	.peer_reset = peer_reset,
};

/* eof */