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Commit 16725b9d authored by Sage Weil's avatar Sage Weil
Browse files

ceph: super.c 



Mount option parsing, client setup and teardown, and a few odds and
ends (e.g., statfs).

Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent c30dbb9c

fs/ceph/super.c

0 → 100644
+936 −0
Original line number Diff line number Diff line 


#include "ceph_debug.h"



#include <linux/backing-dev.h>

#include <linux/fs.h>

#include <linux/inet.h>

#include <linux/in6.h>

#include <linux/module.h>

#include <linux/mount.h>

#include <linux/parser.h>

#include <linux/rwsem.h>

#include <linux/sched.h>

#include <linux/seq_file.h>

#include <linux/statfs.h>

#include <linux/string.h>

#include <linux/version.h>

#include <linux/vmalloc.h>



#include "ceph_ver.h"

#include "decode.h"

#include "super.h"

#include "mon_client.h"



/*

 * Ceph superblock operations

 *

 * Handle the basics of mounting, unmounting.

 */





/*

 * find filename portion of a path (/foo/bar/baz -> baz)

 */

const char *ceph_file_part(const char *s, int len)

{

	const char *e = s + len;



	while (e != s && *(e-1) != '/')

		e--;

	return e;

}





/*

 * super ops

 */

static void ceph_put_super(struct super_block *s)

{

	struct ceph_client *cl = ceph_client(s);



	dout("put_super\n");

	ceph_mdsc_close_sessions(&cl->mdsc);

	return;

}



static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)

{

	struct ceph_client *client = ceph_inode_to_client(dentry->d_inode);

	struct ceph_monmap *monmap = client->monc.monmap;

	struct ceph_statfs st;

	u64 fsid;

	int err;



	dout("statfs\n");

	err = ceph_monc_do_statfs(&client->monc, &st);

	if (err < 0)

		return err;



	/* fill in kstatfs */

	buf->f_type = CEPH_SUPER_MAGIC;  /* ?? */



	/*

	 * express utilization in terms of large blocks to avoid

	 * overflow on 32-bit machines.

	 */

	buf->f_bsize = 1 << CEPH_BLOCK_SHIFT;

	buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);

	buf->f_bfree = (le64_to_cpu(st.kb) - le64_to_cpu(st.kb_used)) >>

		(CEPH_BLOCK_SHIFT-10);

	buf->f_bavail = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);



	buf->f_files = le64_to_cpu(st.num_objects);

	buf->f_ffree = -1;

	buf->f_namelen = PATH_MAX;

	buf->f_frsize = PAGE_CACHE_SIZE;



	/* leave fsid little-endian, regardless of host endianness */

	fsid = *(u64 *)(&monmap->fsid) ^ *((u64 *)&monmap->fsid + 1);

	buf->f_fsid.val[0] = fsid & 0xffffffff;

	buf->f_fsid.val[1] = fsid >> 32;



	return 0;

}





static int ceph_syncfs(struct super_block *sb, int wait)

{

	dout("sync_fs %d\n", wait);

	ceph_osdc_sync(&ceph_client(sb)->osdc);

	ceph_mdsc_sync(&ceph_client(sb)->mdsc);

	return 0;

}





/**

 * ceph_show_options - Show mount options in /proc/mounts

 * @m: seq_file to write to

 * @mnt: mount descriptor

 */

static int ceph_show_options(struct seq_file *m, struct vfsmount *mnt)

{

	struct ceph_client *client = ceph_sb_to_client(mnt->mnt_sb);

	struct ceph_mount_args *args = &client->mount_args;



	if (args->flags & CEPH_OPT_FSID)

		seq_printf(m, ",fsidmajor=%llu,fsidminor%llu",

			   le64_to_cpu(*(__le64 *)&args->fsid.fsid[0]),

			   le64_to_cpu(*(__le64 *)&args->fsid.fsid[8]));

	if (args->flags & CEPH_OPT_NOSHARE)

		seq_puts(m, ",noshare");

	if (args->flags & CEPH_OPT_DIRSTAT)

		seq_puts(m, ",dirstat");

	if ((args->flags & CEPH_OPT_RBYTES) == 0)

		seq_puts(m, ",norbytes");

	if (args->flags & CEPH_OPT_NOCRC)

		seq_puts(m, ",nocrc");

	if (args->flags & CEPH_OPT_NOASYNCREADDIR)

		seq_puts(m, ",noasyncreaddir");

	if (strcmp(args->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))

		seq_printf(m, ",snapdirname=%s", args->snapdir_name);

	if (args->secret)

		seq_puts(m, ",secret=<hidden>");

	return 0;

}



/*

 * caches

 */

struct kmem_cache *ceph_inode_cachep;

struct kmem_cache *ceph_cap_cachep;

struct kmem_cache *ceph_dentry_cachep;

struct kmem_cache *ceph_file_cachep;



static void ceph_inode_init_once(void *foo)

{

	struct ceph_inode_info *ci = foo;

	inode_init_once(&ci->vfs_inode);

}



static int __init init_caches(void)

{

	ceph_inode_cachep = kmem_cache_create("ceph_inode_info",

				      sizeof(struct ceph_inode_info),

				      __alignof__(struct ceph_inode_info),

				      (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),

				      ceph_inode_init_once);

	if (ceph_inode_cachep == NULL)

		return -ENOMEM;



	ceph_cap_cachep = KMEM_CACHE(ceph_cap,

				     SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);

	if (ceph_cap_cachep == NULL)

		goto bad_cap;



	ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,

					SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);

	if (ceph_dentry_cachep == NULL)

		goto bad_dentry;



	ceph_file_cachep = KMEM_CACHE(ceph_file_info,

				      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);

	if (ceph_file_cachep == NULL)

		goto bad_file;



	return 0;



bad_file:

	kmem_cache_destroy(ceph_dentry_cachep);

bad_dentry:

	kmem_cache_destroy(ceph_cap_cachep);

bad_cap:

	kmem_cache_destroy(ceph_inode_cachep);

	return -ENOMEM;

}



static void destroy_caches(void)

{

	kmem_cache_destroy(ceph_inode_cachep);

	kmem_cache_destroy(ceph_cap_cachep);

	kmem_cache_destroy(ceph_dentry_cachep);

	kmem_cache_destroy(ceph_file_cachep);

}





/*

 * ceph_umount_begin - initiate forced umount.  Tear down down the

 * mount, skipping steps that may hang while waiting for server(s).

 */

static void ceph_umount_begin(struct super_block *sb)

{

	struct ceph_client *client = ceph_sb_to_client(sb);



	dout("ceph_umount_begin - starting forced umount\n");

	if (!client)

		return;

	client->mount_state = CEPH_MOUNT_SHUTDOWN;

	return;

}



static const struct super_operations ceph_super_ops = {

	.alloc_inode	= ceph_alloc_inode,

	.destroy_inode	= ceph_destroy_inode,

	.write_inode    = ceph_write_inode,

	.sync_fs        = ceph_syncfs,

	.put_super	= ceph_put_super,

	.show_options   = ceph_show_options,

	.statfs		= ceph_statfs,

	.umount_begin   = ceph_umount_begin,

};





const char *ceph_msg_type_name(int type)

{

	switch (type) {

	case CEPH_MSG_SHUTDOWN: return "shutdown";

	case CEPH_MSG_PING: return "ping";

	case CEPH_MSG_MON_MAP: return "mon_map";

	case CEPH_MSG_MON_GET_MAP: return "mon_get_map";

	case CEPH_MSG_MON_SUBSCRIBE: return "mon_subscribe";

	case CEPH_MSG_MON_SUBSCRIBE_ACK: return "mon_subscribe_ack";

	case CEPH_MSG_CLIENT_MOUNT: return "client_mount";

	case CEPH_MSG_CLIENT_MOUNT_ACK: return "client_mount_ack";

	case CEPH_MSG_STATFS: return "statfs";

	case CEPH_MSG_STATFS_REPLY: return "statfs_reply";

	case CEPH_MSG_MDS_GETMAP: return "mds_getmap";

	case CEPH_MSG_MDS_MAP: return "mds_map";

	case CEPH_MSG_CLIENT_SESSION: return "client_session";

	case CEPH_MSG_CLIENT_RECONNECT: return "client_reconnect";

	case CEPH_MSG_CLIENT_REQUEST: return "client_request";

	case CEPH_MSG_CLIENT_REQUEST_FORWARD: return "client_request_forward";

	case CEPH_MSG_CLIENT_REPLY: return "client_reply";

	case CEPH_MSG_CLIENT_CAPS: return "client_caps";

	case CEPH_MSG_CLIENT_CAPRELEASE: return "client_cap_release";

	case CEPH_MSG_CLIENT_SNAP: return "client_snap";

	case CEPH_MSG_CLIENT_LEASE: return "client_lease";

	case CEPH_MSG_OSD_GETMAP: return "osd_getmap";

	case CEPH_MSG_OSD_MAP: return "osd_map";

	case CEPH_MSG_OSD_OP: return "osd_op";

	case CEPH_MSG_OSD_OPREPLY: return "osd_opreply";

	default: return "unknown";

	}

}





/*

 * mount options

 */

enum {

	Opt_fsidmajor,

	Opt_fsidminor,

	Opt_monport,

	Opt_wsize,

	Opt_rsize,

	Opt_osdtimeout,

	Opt_mount_timeout,

	Opt_caps_wanted_delay_min,

	Opt_caps_wanted_delay_max,

	Opt_readdir_max_entries,

	/* int args above */

	Opt_snapdirname,

	Opt_secret,

	/* string args above */

	Opt_ip,

	Opt_noshare,

	Opt_dirstat,

	Opt_nodirstat,

	Opt_rbytes,

	Opt_norbytes,

	Opt_nocrc,

	Opt_noasyncreaddir,

};



static match_table_t arg_tokens = {

	{Opt_fsidmajor, "fsidmajor=%ld"},

	{Opt_fsidminor, "fsidminor=%ld"},

	{Opt_monport, "monport=%d"},

	{Opt_wsize, "wsize=%d"},

	{Opt_rsize, "rsize=%d"},

	{Opt_osdtimeout, "osdtimeout=%d"},

	{Opt_mount_timeout, "mount_timeout=%d"},

	{Opt_caps_wanted_delay_min, "caps_wanted_delay_min=%d"},

	{Opt_caps_wanted_delay_max, "caps_wanted_delay_max=%d"},

	{Opt_readdir_max_entries, "readdir_max_entries=%d"},

	/* int args above */

	{Opt_snapdirname, "snapdirname=%s"},

	{Opt_secret, "secret=%s"},

	/* string args above */

	{Opt_ip, "ip=%s"},

	{Opt_noshare, "noshare"},

	{Opt_dirstat, "dirstat"},

	{Opt_nodirstat, "nodirstat"},

	{Opt_rbytes, "rbytes"},

	{Opt_norbytes, "norbytes"},

	{Opt_nocrc, "nocrc"},

	{Opt_noasyncreaddir, "noasyncreaddir"},

	{-1, NULL}

};





static int parse_mount_args(struct ceph_client *client,

			    int flags, char *options, const char *dev_name,

			    const char **path)

{

	struct ceph_mount_args *args = &client->mount_args;

	const char *c;

	int err;

	substring_t argstr[MAX_OPT_ARGS];

	int num_mon;

	struct ceph_entity_addr mon_addr[CEPH_MAX_MON_MOUNT_ADDR];

	int i;



	dout("parse_mount_args dev_name '%s'\n", dev_name);

	memset(args, 0, sizeof(*args));



	/* start with defaults */

	args->sb_flags = flags;

	args->flags = CEPH_OPT_DEFAULT;

	args->osd_timeout = 5;    /* seconds */

	args->mount_timeout = CEPH_MOUNT_TIMEOUT_DEFAULT; /* seconds */

	args->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;

	args->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;

	args->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);

	args->cap_release_safety = CEPH_CAPS_PER_RELEASE * 4;

	args->max_readdir = 1024;



	/* ip1[:port1][,ip2[:port2]...]:/subdir/in/fs */

	if (!dev_name)

		return -EINVAL;

	*path = strstr(dev_name, ":/");

	if (*path == NULL) {

		pr_err("device name is missing path (no :/ in %s)\n",

		       dev_name);

		return -EINVAL;

	}



	/* get mon ip(s) */

	err = ceph_parse_ips(dev_name, *path, mon_addr,

			     CEPH_MAX_MON_MOUNT_ADDR, &num_mon);

	if (err < 0)

		return err;



	/* build initial monmap */

	client->monc.monmap = kzalloc(sizeof(*client->monc.monmap) +

			       num_mon*sizeof(client->monc.monmap->mon_inst[0]),

			       GFP_KERNEL);

	if (!client->monc.monmap)

		return -ENOMEM;

	for (i = 0; i < num_mon; i++) {

		client->monc.monmap->mon_inst[i].addr = mon_addr[i];

		client->monc.monmap->mon_inst[i].addr.erank = 0;

		client->monc.monmap->mon_inst[i].addr.nonce = 0;

		client->monc.monmap->mon_inst[i].name.type =

			CEPH_ENTITY_TYPE_MON;

		client->monc.monmap->mon_inst[i].name.num = cpu_to_le64(i);

	}

	client->monc.monmap->num_mon = num_mon;

	memset(&args->my_addr.in_addr, 0, sizeof(args->my_addr.in_addr));



	/* path on server */

	*path += 2;

	dout("server path '%s'\n", *path);



	/* parse mount options */

	while ((c = strsep(&options, ",")) != NULL) {

		int token, intval, ret;

		if (!*c)

			continue;

		token = match_token((char *)c, arg_tokens, argstr);

		if (token < 0) {

			pr_err("bad mount option at '%s'\n", c);

			return -EINVAL;



		}

		if (token < Opt_ip) {

			ret = match_int(&argstr[0], &intval);

			if (ret < 0) {

				pr_err("bad mount option arg (not int) "

				       "at '%s'\n", c);

				continue;

			}

			dout("got token %d intval %d\n", token, intval);

		}

		switch (token) {

		case Opt_fsidmajor:

			*(__le64 *)&args->fsid.fsid[0] = cpu_to_le64(intval);

			break;

		case Opt_fsidminor:

			*(__le64 *)&args->fsid.fsid[8] = cpu_to_le64(intval);

			break;

		case Opt_ip:

			err = ceph_parse_ips(argstr[0].from,

					     argstr[0].to,

					     &args->my_addr,

					     1, NULL);

			if (err < 0)

				return err;

			args->flags |= CEPH_OPT_MYIP;

			break;



		case Opt_snapdirname:

			kfree(args->snapdir_name);

			args->snapdir_name = kstrndup(argstr[0].from,

					      argstr[0].to-argstr[0].from,

					      GFP_KERNEL);

			break;

		case Opt_secret:

			args->secret = kstrndup(argstr[0].from,

						argstr[0].to-argstr[0].from,

						GFP_KERNEL);

			break;



			/* misc */

		case Opt_wsize:

			args->wsize = intval;

			break;

		case Opt_rsize:

			args->rsize = intval;

			break;

		case Opt_osdtimeout:

			args->osd_timeout = intval;

			break;

		case Opt_mount_timeout:

			args->mount_timeout = intval;

			break;

		case Opt_caps_wanted_delay_min:

			args->caps_wanted_delay_min = intval;

			break;

		case Opt_caps_wanted_delay_max:

			args->caps_wanted_delay_max = intval;

			break;

		case Opt_readdir_max_entries:

			args->max_readdir = intval;

			break;



		case Opt_noshare:

			args->flags |= CEPH_OPT_NOSHARE;

			break;



		case Opt_dirstat:

			args->flags |= CEPH_OPT_DIRSTAT;

			break;

		case Opt_nodirstat:

			args->flags &= ~CEPH_OPT_DIRSTAT;

			break;

		case Opt_rbytes:

			args->flags |= CEPH_OPT_RBYTES;

			break;

		case Opt_norbytes:

			args->flags &= ~CEPH_OPT_RBYTES;

			break;

		case Opt_nocrc:

			args->flags |= CEPH_OPT_NOCRC;

			break;

		case Opt_noasyncreaddir:

			args->flags |= CEPH_OPT_NOASYNCREADDIR;

			break;



		default:

			BUG_ON(token);

		}

	}



	return 0;

}



static void release_mount_args(struct ceph_mount_args *args)

{

	kfree(args->snapdir_name);

	args->snapdir_name = NULL;

	kfree(args->secret);

	args->secret = NULL;

}



/*

 * create a fresh client instance

 */

static struct ceph_client *ceph_create_client(void)

{

	struct ceph_client *client;

	int err = -ENOMEM;



	client = kzalloc(sizeof(*client), GFP_KERNEL);

	if (client == NULL)

		return ERR_PTR(-ENOMEM);



	mutex_init(&client->mount_mutex);



	init_waitqueue_head(&client->mount_wq);



	client->sb = NULL;

	client->mount_state = CEPH_MOUNT_MOUNTING;

	client->whoami = -1;



	client->msgr = NULL;



	client->mount_err = 0;

	client->signed_ticket = NULL;

	client->signed_ticket_len = 0;



	err = -ENOMEM;

	client->wb_wq = create_workqueue("ceph-writeback");

	if (client->wb_wq == NULL)

		goto fail;

	client->pg_inv_wq = create_singlethread_workqueue("ceph-pg-invalid");

	if (client->pg_inv_wq == NULL)

		goto fail_wb_wq;

	client->trunc_wq = create_singlethread_workqueue("ceph-trunc");

	if (client->trunc_wq == NULL)

		goto fail_pg_inv_wq;



	/* subsystems */

	err = ceph_monc_init(&client->monc, client);

	if (err < 0)

		goto fail_trunc_wq;

	err = ceph_osdc_init(&client->osdc, client);

	if (err < 0)

		goto fail_monc;

	ceph_mdsc_init(&client->mdsc, client);

	return client;



fail_monc:

	ceph_monc_stop(&client->monc);

fail_trunc_wq:

	destroy_workqueue(client->trunc_wq);

fail_pg_inv_wq:

	destroy_workqueue(client->pg_inv_wq);

fail_wb_wq:

	destroy_workqueue(client->wb_wq);

fail:

	kfree(client);

	return ERR_PTR(err);

}



static void ceph_destroy_client(struct ceph_client *client)

{

	dout("destroy_client %p\n", client);



	/* unmount */

	ceph_mdsc_stop(&client->mdsc);

	ceph_monc_stop(&client->monc);

	ceph_osdc_stop(&client->osdc);



	kfree(client->signed_ticket);



	ceph_debugfs_client_cleanup(client);

	destroy_workqueue(client->wb_wq);

	destroy_workqueue(client->pg_inv_wq);

	destroy_workqueue(client->trunc_wq);



	if (client->msgr)

		ceph_messenger_destroy(client->msgr);

	if (client->wb_pagevec_pool)

		mempool_destroy(client->wb_pagevec_pool);



	release_mount_args(&client->mount_args);



	kfree(client);

	dout("destroy_client %p done\n", client);

}



/*

 * true if we have the mon map (and have thus joined the cluster)

 */

static int have_mon_map(struct ceph_client *client)

{

	return client->monc.monmap && client->monc.monmap->epoch;

}



/*

 * Bootstrap mount by opening the root directory.  Note the mount

 * @started time from caller, and time out if this takes too long.

 */

static struct dentry *open_root_dentry(struct ceph_client *client,

				       const char *path,

				       unsigned long started)

{

	struct ceph_mds_client *mdsc = &client->mdsc;

	struct ceph_mds_request *req = NULL;

	int err;

	struct dentry *root;



	/* open dir */

	dout("open_root_inode opening '%s'\n", path);

	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);

	if (IS_ERR(req))

		return ERR_PTR(PTR_ERR(req));

	req->r_path1 = kstrdup(path, GFP_NOFS);

	req->r_ino1.ino = CEPH_INO_ROOT;

	req->r_ino1.snap = CEPH_NOSNAP;

	req->r_started = started;

	req->r_timeout = client->mount_args.mount_timeout * HZ;

	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);

	req->r_num_caps = 2;

	err = ceph_mdsc_do_request(mdsc, NULL, req);

	if (err == 0) {

		dout("open_root_inode success\n");

		if (ceph_ino(req->r_target_inode) == CEPH_INO_ROOT &&

		    client->sb->s_root == NULL)

			root = d_alloc_root(req->r_target_inode);

		else

			root = d_obtain_alias(req->r_target_inode);

		req->r_target_inode = NULL;

		dout("open_root_inode success, root dentry is %p\n", root);

	} else {

		root = ERR_PTR(err);

	}

	ceph_mdsc_put_request(req);

	return root;

}



/*

 * mount: join the ceph cluster, and open root directory.

 */

static int ceph_mount(struct ceph_client *client, struct vfsmount *mnt,

		      const char *path)

{

	struct ceph_entity_addr *myaddr = NULL;

	int err;

	unsigned long timeout = client->mount_args.mount_timeout * HZ;

	unsigned long started = jiffies;  /* note the start time */

	struct dentry *root;



	dout("mount start\n");

	mutex_lock(&client->mount_mutex);



	/* initialize the messenger */

	if (client->msgr == NULL) {

		if (ceph_test_opt(client, MYIP))

			myaddr = &client->mount_args.my_addr;

		client->msgr = ceph_messenger_create(myaddr);

		if (IS_ERR(client->msgr)) {

			err = PTR_ERR(client->msgr);

			client->msgr = NULL;

			goto out;

		}

		client->msgr->nocrc = ceph_test_opt(client, NOCRC);

	}



	/* send mount request, and wait for mon, mds, and osd maps */

	err = ceph_monc_request_mount(&client->monc);

	if (err < 0)

		goto out;



	while (!have_mon_map(client) && !client->mount_err) {

		err = -EIO;

		if (timeout && time_after_eq(jiffies, started + timeout))

			goto out;



		/* wait */

		dout("mount waiting for mount\n");

		err = wait_event_interruptible_timeout(client->mount_wq,

			       client->mount_err || have_mon_map(client),

			       timeout);

		if (err == -EINTR || err == -ERESTARTSYS)

			goto out;

		if (client->mount_err) {

			err = client->mount_err;

			goto out;

		}

	}



	dout("mount opening root\n");

	root = open_root_dentry(client, "", started);

	if (IS_ERR(root)) {

		err = PTR_ERR(root);

		goto out;

	}

	if (client->sb->s_root)

		dput(root);

	else

		client->sb->s_root = root;



	if (path[0] == 0) {

		dget(root);

	} else {

		dout("mount opening base mountpoint\n");

		root = open_root_dentry(client, path, started);

		if (IS_ERR(root)) {

			err = PTR_ERR(root);

			dput(client->sb->s_root);

			client->sb->s_root = NULL;

			goto out;

		}

	}



	mnt->mnt_root = root;

	mnt->mnt_sb = client->sb;



	client->mount_state = CEPH_MOUNT_MOUNTED;

	dout("mount success\n");

	err = 0;



out:

	mutex_unlock(&client->mount_mutex);

	return err;

}



static int ceph_set_super(struct super_block *s, void *data)

{

	struct ceph_client *client = data;

	int ret;



	dout("set_super %p data %p\n", s, data);



	s->s_flags = client->mount_args.sb_flags;

	s->s_maxbytes = 1ULL << 40;  /* temp value until we get mdsmap */



	s->s_fs_info = client;

	client->sb = s;



	s->s_op = &ceph_super_ops;

	s->s_export_op = &ceph_export_ops;



	s->s_time_gran = 1000;  /* 1000 ns == 1 us */



	ret = set_anon_super(s, NULL);  /* what is that second arg for? */

	if (ret != 0)

		goto fail;



	return ret;



fail:

	s->s_fs_info = NULL;

	client->sb = NULL;

	return ret;

}



/*

 * share superblock if same fs AND options

 */

static int ceph_compare_super(struct super_block *sb, void *data)

{

	struct ceph_client *new = data;

	struct ceph_mount_args *args = &new->mount_args;

	struct ceph_client *other = ceph_sb_to_client(sb);

	int i;



	dout("ceph_compare_super %p\n", sb);

	if (args->flags & CEPH_OPT_FSID) {

		if (ceph_fsid_compare(&args->fsid, &other->fsid)) {

			dout("fsid doesn't match\n");

			return 0;

		}

	} else {

		/* do we share (a) monitor? */

		for (i = 0; i < new->monc.monmap->num_mon; i++)

			if (ceph_monmap_contains(other->monc.monmap,

					 &new->monc.monmap->mon_inst[i].addr))

				break;

		if (i == new->monc.monmap->num_mon) {

			dout("mon ip not part of monmap\n");

			return 0;

		}

		dout("mon ip matches existing sb %p\n", sb);

	}

	if (args->sb_flags != other->mount_args.sb_flags) {

		dout("flags differ\n");

		return 0;

	}

	return 1;

}



/*

 * construct our own bdi so we can control readahead, etc.

 */

static int ceph_init_bdi(struct super_block *sb, struct ceph_client *client)

{

	int err;



	err = bdi_init(&client->backing_dev_info);

	if (err < 0)

		return err;



	/* set ra_pages based on rsize mount option? */

	if (client->mount_args.rsize >= PAGE_CACHE_SIZE)

		client->backing_dev_info.ra_pages =

			(client->mount_args.rsize + PAGE_CACHE_SIZE - 1)

			>> PAGE_SHIFT;



	err = bdi_register_dev(&client->backing_dev_info, sb->s_dev);

	return err;

}



static int ceph_get_sb(struct file_system_type *fs_type,

		       int flags, const char *dev_name, void *data,

		       struct vfsmount *mnt)

{

	struct super_block *sb;

	struct ceph_client *client;

	int err;

	int (*compare_super)(struct super_block *, void *) = ceph_compare_super;

	const char *path;



	dout("ceph_get_sb\n");



	/* create client (which we may/may not use) */

	client = ceph_create_client();

	if (IS_ERR(client))

		return PTR_ERR(client);



	err = parse_mount_args(client, flags, data, dev_name, &path);

	if (err < 0)

		goto out;



	if (client->mount_args.flags & CEPH_OPT_NOSHARE)

		compare_super = NULL;

	sb = sget(fs_type, compare_super, ceph_set_super, client);

	if (IS_ERR(sb)) {

		err = PTR_ERR(sb);

		goto out;

	}



	if (ceph_client(sb) != client) {

		ceph_destroy_client(client);

		client = ceph_client(sb);

		dout("get_sb got existing client %p\n", client);

	} else {

		dout("get_sb using new client %p\n", client);



		/* set up mempools */

		err = -ENOMEM;

		client->wb_pagevec_pool = mempool_create_kmalloc_pool(10,

			      client->mount_args.wsize >> PAGE_CACHE_SHIFT);

		if (!client->wb_pagevec_pool)

			goto out_splat;



		err = ceph_init_bdi(sb, client);

		if (err < 0)

			goto out_splat;

	}



	err = ceph_mount(client, mnt, path);

	if (err < 0)

		goto out_splat;

	dout("root %p inode %p ino %llx.%llx\n", mnt->mnt_root,

	     mnt->mnt_root->d_inode, ceph_vinop(mnt->mnt_root->d_inode));

	return 0;



out_splat:

	ceph_mdsc_close_sessions(&client->mdsc);

	up_write(&sb->s_umount);

	deactivate_super(sb);

	goto out_final;



out:

	ceph_destroy_client(client);

out_final:

	dout("ceph_get_sb fail %d\n", err);

	return err;

}



static void ceph_kill_sb(struct super_block *s)

{

	struct ceph_client *client = ceph_sb_to_client(s);

	dout("kill_sb %p\n", s);

	ceph_mdsc_pre_umount(&client->mdsc);

	bdi_unregister(&client->backing_dev_info);

	kill_anon_super(s);    /* will call put_super after sb is r/o */

	bdi_destroy(&client->backing_dev_info);

	ceph_destroy_client(client);

}



static struct file_system_type ceph_fs_type = {

	.owner		= THIS_MODULE,

	.name		= "ceph",

	.get_sb		= ceph_get_sb,

	.kill_sb	= ceph_kill_sb,

	.fs_flags	= FS_RENAME_DOES_D_MOVE,

};



#define _STRINGIFY(x) #x

#define STRINGIFY(x) _STRINGIFY(x)



static int __init init_ceph(void)

{

	int ret = 0;



	ret = ceph_debugfs_init();

	if (ret < 0)

		goto out;



	ret = ceph_msgr_init();

	if (ret < 0)

		goto out_debugfs;



	ret = init_caches();

	if (ret)

		goto out_msgr;



	ceph_caps_init();



	ret = register_filesystem(&ceph_fs_type);

	if (ret)

		goto out_icache;



	pr_info("loaded (%s)\n", STRINGIFY(CEPH_GIT_VER));

	return 0;



out_icache:

	destroy_caches();

out_msgr:

	ceph_msgr_exit();

out_debugfs:

	ceph_debugfs_cleanup();

out:

	return ret;

}



static void __exit exit_ceph(void)

{

	dout("exit_ceph\n");

	unregister_filesystem(&ceph_fs_type);

	ceph_caps_finalize();

	destroy_caches();

	ceph_msgr_exit();

	ceph_debugfs_cleanup();

}



module_init(init_ceph);

module_exit(exit_ceph);



MODULE_AUTHOR("Sage Weil <sage@newdream.net>");

MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");

MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");

MODULE_DESCRIPTION("Ceph filesystem for Linux");

MODULE_LICENSE("GPL");