Date:	Thu, 13 Nov 2008 16:56:03 -0800
From:	Sage Weil <sage@...dream.net>
To:	linux-fsdevel@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, Sage Weil <sage@...dream.net>
Subject: [PATCH 04/19] ceph: super.c

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

Signed-off-by: Sage Weil <sage@...dream.net>
---
 fs/ceph/super.c | 1165 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 1165 insertions(+), 0 deletions(-)
 create mode 100644 fs/ceph/super.c

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
new file mode 100644
index 0000000..235c091
--- /dev/null
+++ b/fs/ceph/super.c
@@ -0,0 +1,1165 @@
+#include <linux/module.h>
+#include <linux/parser.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/rwsem.h>
+#include <linux/seq_file.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/version.h>
+#include <linux/backing-dev.h>
+#include <linux/statfs.h>
+
+/* debug levels; defined in super.h */
+
+#include "ceph_debug.h"
+
+/*
+ * global debug value.
+ *  0 = quiet.
+ *
+ * if the per-file debug level >= 0, then that overrides this  global
+ * debug level.
+ */
+int ceph_debug = 1;
+int ceph_debug_mask = 0xffffffff;
+/* if true, send output to KERN_INFO (console) instead of KERN_DEBUG. */
+int ceph_debug_console;
+int ceph_debug_super = -1;   /* for this file */
+
+#define DOUT_MASK DOUT_MASK_SUPER
+#define DOUT_VAR ceph_debug_super
+#define DOUT_PREFIX "super: "
+#include "super.h"
+
+#include "mon_client.h"
+
+void ceph_dispatch(void *p, struct ceph_msg *msg);
+void ceph_peer_reset(void *p, struct ceph_entity_addr *peer_addr,
+		     struct ceph_entity_name *peer_name);
+
+
+/*
+ * super ops
+ */
+static int ceph_write_inode(struct inode *inode, int unused)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	if (memcmp(&ci->i_old_atime, &inode->i_atime, sizeof(struct timeval))) {
+		dout(30, "ceph_write_inode %llx.%llx .. atime updated\n",
+		     ceph_vinop(inode));
+		/* maybe someday we will push this async to mds? */
+	}
+	return 0;
+}
+
+static void ceph_put_super(struct super_block *s)
+{
+	struct ceph_client *cl = ceph_client(s);
+	int rc;
+	int seconds = 15;
+
+	dout(30, "put_super\n");
+	ceph_mdsc_close_sessions(&cl->mdsc);
+	ceph_monc_request_umount(&cl->monc);
+
+	if (cl->mount_state != CEPH_MOUNT_SHUTDOWN) {
+		rc = wait_event_timeout(cl->mount_wq,
+				(cl->mount_state == CEPH_MOUNT_UNMOUNTED),
+				seconds*HZ);
+		if (rc == 0)
+			derr(0, "umount timed out after %d seconds\n", seconds);
+	}
+
+	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;
+	__le64 fsid;
+	int err;
+
+	dout(30, "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;     /* 1 MB */
+	buf->f_blocks = le64_to_cpu(st.f_total) >> (CEPH_BLOCK_SHIFT-10);
+	buf->f_bfree = le64_to_cpu(st.f_free) >> (CEPH_BLOCK_SHIFT-10);
+	buf->f_bavail = le64_to_cpu(st.f_avail) >> (CEPH_BLOCK_SHIFT-10);
+
+	buf->f_files = le64_to_cpu(st.f_objects);
+	buf->f_ffree = -1;
+	buf->f_namelen = PATH_MAX;
+	buf->f_frsize = PAGE_CACHE_SIZE;
+
+	/* leave in little-endian, regardless of host endianness */
+	fsid = monmap->fsid.major ^ monmap->fsid.minor;
+	buf->f_fsid.val[0] = le64_to_cpu(fsid) & 0xffffffff;
+	buf->f_fsid.val[1] = le64_to_cpu(fsid) >> 32;
+
+	return 0;
+}
+
+
+static int ceph_syncfs(struct super_block *sb, int wait)
+{
+	dout(10, "sync_fs %d\n", wait);
+	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 (ceph_debug != 0)
+		seq_printf(m, ",debug=%d", ceph_debug);
+	if (args->flags & CEPH_MOUNT_FSID)
+		seq_printf(m, ",fsidmajor=%llu,fsidminor%llu",
+			   args->fsid.major, args->fsid.minor);
+	if (args->flags & CEPH_MOUNT_NOSHARE)
+		seq_puts(m, ",noshare");
+	if (args->flags & CEPH_MOUNT_UNSAFE_WRITEBACK)
+		seq_puts(m, ",unsafewriteback");
+	if (args->flags & CEPH_MOUNT_DIRSTAT)
+		seq_puts(m, ",dirstat");
+	else
+		seq_puts(m, ",nodirstat");
+	if (args->flags & CEPH_MOUNT_RBYTES)
+		seq_puts(m, ",rbytes");
+	else
+		seq_puts(m, ",norbytes");
+	if (args->flags & CEPH_MOUNT_NOCRC)
+		seq_puts(m, ",nocrc");
+	return 0;
+}
+
+
+/*
+ * inode cache
+ */
+struct kmem_cache *ceph_inode_cachep;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
+static void init_once(void *foo)
+#else
+static void init_once(struct kmem_cache *cachep, void *foo)
+#endif
+{
+	struct ceph_inode_info *ci = foo;
+	inode_init_once(&ci->vfs_inode);
+}
+
+static int init_inodecache(void)
+{
+	ceph_inode_cachep = kmem_cache_create("ceph_inode_cache",
+					      sizeof(struct ceph_inode_info),
+					      0, (SLAB_RECLAIM_ACCOUNT|
+						  SLAB_MEM_SPREAD),
+					      init_once);
+	if (ceph_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	kmem_cache_destroy(ceph_inode_cachep);
+}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26)
+static void ceph_umount_begin(struct vfsmount *vfsmnt, int flags)
+#else
+static void ceph_umount_begin(struct super_block *sb)
+#endif
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26)
+	struct ceph_client *client = ceph_sb_to_client(vfsmnt->mnt_sb);
+#else
+	struct ceph_client *client = ceph_sb_to_client(sb);
+#endif
+
+	dout(30, "ceph_umount_begin\n");
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26)
+	if (!(flags & MNT_FORCE))
+		return;
+#endif
+
+	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,
+};
+
+
+
+/*
+ * the monitor responds with monmap to indicate mount success.
+ * (or, someday, to indicate a change in the monitor cluster)
+ */
+static void handle_monmap(struct ceph_client *client, struct ceph_msg *msg)
+{
+	int err;
+	int first = (client->monc.monmap->epoch == 0);
+	struct ceph_monmap *new, *old = client->monc.monmap;
+
+	dout(2, "handle_monmap had epoch %d\n", client->monc.monmap->epoch);
+	new = ceph_monmap_decode(msg->front.iov_base,
+				 msg->front.iov_base + msg->front.iov_len);
+	if (IS_ERR(new)) {
+		err = PTR_ERR(new);
+		derr(0, "problem decoding monmap, %d\n", err);
+		return;
+	}
+	client->monc.monmap = new;
+	kfree(old);
+
+	if (first) {
+		char name[10];
+		client->whoami = le32_to_cpu(msg->hdr.dst.name.num);
+		client->msgr->inst.name = msg->hdr.dst.name;
+		sprintf(name, "client%d", client->whoami);
+		dout(1, "i am %s, fsid is %llx.%llx\n", name,
+		     le64_to_cpu(client->monc.monmap->fsid.major),
+		     le64_to_cpu(client->monc.monmap->fsid.minor));
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
+		client->client_kobj = kobject_create_and_add(name, ceph_kobj);
+		/*
+		  client->fsid_kobj = kobject_create_and_add("fsid",
+		  client->client_kobj);
+		*/
+#endif
+	}
+}
+
+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_CLIENT_MOUNT: return "client_mount";
+	case CEPH_MSG_CLIENT_UNMOUNT: return "client_unmount";
+	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_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";
+	}
+}
+
+/*
+ * Called when a message socket is explicitly reset by a peer.
+ */
+void ceph_peer_reset(void *p, struct ceph_entity_addr *peer_addr,
+		     struct ceph_entity_name *peer_name)
+{
+	struct ceph_client *client = p;
+
+	dout(30, "ceph_peer_reset %s%d\n", ENTITY_NAME(*peer_name));
+	switch (le32_to_cpu(peer_name->type)) {
+	case CEPH_ENTITY_TYPE_MDS:
+		ceph_mdsc_handle_reset(&client->mdsc,
+					      le32_to_cpu(peer_name->num));
+		break;
+	case CEPH_ENTITY_TYPE_OSD:
+		ceph_osdc_handle_reset(&client->osdc, peer_addr);
+		break;
+	}
+}
+
+
+/*
+ * mount options
+ */
+enum {
+	Opt_fsidmajor,
+	Opt_fsidminor,
+	Opt_debug,
+	Opt_debug_console,
+	Opt_debug_msgr,
+	Opt_debug_mdsc,
+	Opt_debug_osdc,
+	Opt_debug_addr,
+	Opt_debug_inode,
+	Opt_debug_snap,
+	Opt_debug_ioctl,
+	Opt_debug_caps,
+	Opt_monport,
+	Opt_port,
+	Opt_wsize,
+	Opt_rsize,
+	Opt_osdtimeout,
+	Opt_mount_timeout,
+	/* int args above */
+	Opt_ip,
+	Opt_noshare,
+	Opt_unsafewriteback,
+	Opt_safewriteback,
+	Opt_dirstat,
+	Opt_nodirstat,
+	Opt_rbytes,
+	Opt_norbytes,
+	Opt_nocrc,
+};
+
+static match_table_t arg_tokens = {
+	{Opt_fsidmajor, "fsidmajor=%ld"},
+	{Opt_fsidminor, "fsidminor=%ld"},
+	{Opt_debug, "debug=%d"},
+	{Opt_debug_msgr, "debug_msgr=%d"},
+	{Opt_debug_mdsc, "debug_mdsc=%d"},
+	{Opt_debug_osdc, "debug_osdc=%d"},
+	{Opt_debug_addr, "debug_addr=%d"},
+	{Opt_debug_inode, "debug_inode=%d"},
+	{Opt_debug_snap, "debug_snap=%d"},
+	{Opt_debug_ioctl, "debug_ioctl=%d"},
+	{Opt_debug_caps, "debug_caps=%d"},
+	{Opt_monport, "monport=%d"},
+	{Opt_port, "port=%d"},
+	{Opt_wsize, "wsize=%d"},
+	{Opt_rsize, "rsize=%d"},
+	{Opt_osdtimeout, "osdtimeout=%d"},
+	{Opt_mount_timeout, "mount_timeout=%d"},
+	/* int args above */
+	{Opt_ip, "ip=%s"},
+	{Opt_debug_console, "debug_console"},
+	{Opt_noshare, "noshare"},
+	{Opt_unsafewriteback, "unsafewriteback"},
+	{Opt_safewriteback, "safewriteback"},
+	{Opt_dirstat, "dirstat"},
+	{Opt_nodirstat, "nodirstat"},
+	{Opt_rbytes, "rbytes"},
+	{Opt_norbytes, "norbytes"},
+	{Opt_nocrc, "nocrc"},
+	{-1, NULL}
+};
+
+#define ADDR_DELIM(c) ((!c) || (c == ':') || (c == ','))
+
+/*
+ * FIXME: add error checking to ip parsing
+ */
+static int parse_ip(const char *c, int len, struct ceph_entity_addr *addr,
+		    int max_count, int *count)
+{
+	int i;
+	int v;
+	int mon_count;
+	unsigned ip = 0;
+	const char *p = c, *numstart;
+
+	dout(15, "parse_ip on '%s' len %d\n", c, len);
+	for (mon_count = 0; mon_count < max_count; mon_count++) {
+		for (i = 0; !ADDR_DELIM(*p) && i < 4; i++) {
+			v = 0;
+			numstart = p;
+			while (!ADDR_DELIM(*p) && *p != '.' && p < c+len) {
+				if (*p < '0' || *p > '9')
+					goto bad;
+				v = (v * 10) + (*p - '0');
+				p++;
+			}
+			if (v > 255 || numstart == p)
+				goto bad;
+			ip = (ip << 8) + v;
+
+			if (*p == '.')
+				p++;
+		}
+		if (i != 4)
+			goto bad;
+		*(__be32 *)&addr[mon_count].ipaddr.sin_addr.s_addr = htonl(ip);
+
+		/* port? */
+		if (*p == ':') {
+			p++;
+			numstart = p;
+			v = 0;
+			while (!ADDR_DELIM(*p) && *p != '.' && p < c+len) {
+				if (*p < '0' || *p > '9')
+					goto bad;
+				v = (v * 10) + (*p - '0');
+				p++;
+			}
+			if (v > 65535 || numstart == p)
+				goto bad;
+			addr[mon_count].ipaddr.sin_port = htons(v);
+		} else
+			addr[mon_count].ipaddr.sin_port = htons(CEPH_MON_PORT);
+
+		dout(15, "parse_ip got %u.%u.%u.%u:%u\n",
+		     IPQUADPORT(addr[mon_count].ipaddr));
+
+		if (*p != ',')
+			break;
+		p++;
+	}
+
+	if (p < c+len)
+		goto bad;
+
+	if (count)
+		*count = mon_count + 1;
+
+	return 0;
+
+bad:
+	derr(1, "parse_ip bad ip '%s'\n", c);
+	return -EINVAL;
+}
+
+static int parse_mount_args(int flags, char *options, const char *dev_name,
+			    struct ceph_mount_args *args, const char **path)
+{
+	char *c;
+	int len, err;
+	substring_t argstr[MAX_OPT_ARGS];
+	int i;
+
+	dout(15, "parse_mount_args dev_name '%s'\n", dev_name);
+	memset(args, 0, sizeof(*args));
+
+	/* defaults */
+	args->sb_flags = flags;
+	args->flags = CEPH_MOUNT_DEFAULT;
+	args->osd_timeout = 5;    /* seconds */
+	args->mount_timeout = 30; /* seconds */
+	args->snapdir_name = ".snap";
+
+	/* ip1[:port1][,ip2[:port2]...]:/subdir/in/fs */
+	c = strstr(dev_name, ":/");
+	if (c == NULL)
+		return -EINVAL;
+	*c = 0;
+
+	/* get mon ip(s) */
+	len = c - dev_name;
+	err = parse_ip(dev_name, len, args->mon_addr, MAX_MON_MOUNT_ADDR,
+		       &args->num_mon);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < args->num_mon; i++) {
+		args->mon_addr[i].ipaddr.sin_family = AF_INET;
+		args->mon_addr[i].erank = 0;
+		args->mon_addr[i].nonce = 0;
+	}
+	args->my_addr.ipaddr.sin_family = AF_INET;
+	args->my_addr.ipaddr.sin_addr.s_addr = htonl(0);
+	args->my_addr.ipaddr.sin_port = htons(0);
+
+	/* path on server */
+	c++;
+	while (*c == '/')
+		c++;  /* remove leading '/'(s) */
+	*path = c;
+	dout(15, "server path '%s'\n", *path);
+
+	/* parse mount options */
+	while ((c = strsep(&options, ",")) != NULL) {
+		int token, intval, ret;
+		if (!*c)
+			continue;
+		token = match_token(c, arg_tokens, argstr);
+		if (token < 0) {
+			derr(0, "bad mount option at '%s'\n", c);
+			return -EINVAL;
+
+		}
+		if (token < Opt_ip) {
+			ret = match_int(&argstr[0], &intval);
+			if (ret < 0) {
+				dout(0, "bad mount arg, not int\n");
+				continue;
+			}
+			dout(30, "got token %d intval %d\n", token, intval);
+		}
+		switch (token) {
+		case Opt_fsidmajor:
+			args->fsid.major = cpu_to_le64(intval);
+			break;
+		case Opt_fsidminor:
+			args->fsid.minor = cpu_to_le64(intval);
+			break;
+		case Opt_port:
+			args->my_addr.ipaddr.sin_port = htons(intval);
+			break;
+		case Opt_ip:
+			err = parse_ip(argstr[0].from,
+					argstr[0].to-argstr[0].from,
+					&args->my_addr,
+					1, NULL);
+			if (err < 0)
+				return err;
+			args->flags |= CEPH_MOUNT_MYIP;
+			break;
+
+			/* debug levels */
+		case Opt_debug:
+			ceph_debug = intval;
+			break;
+		case Opt_debug_msgr:
+			ceph_debug_msgr = intval;
+			break;
+		case Opt_debug_mdsc:
+			ceph_debug_mdsc = intval;
+			break;
+		case Opt_debug_osdc:
+			ceph_debug_osdc = intval;
+			break;
+		case Opt_debug_addr:
+			ceph_debug_addr = intval;
+			break;
+		case Opt_debug_inode:
+			ceph_debug_inode = intval;
+			break;
+		case Opt_debug_snap:
+			ceph_debug_snap = intval;
+			break;
+		case Opt_debug_ioctl:
+			ceph_debug_ioctl = intval;
+			break;
+		case Opt_debug_caps:
+			ceph_debug_caps = intval;
+			break;
+		case Opt_debug_console:
+			ceph_debug_console = 1;
+			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_noshare:
+			args->flags |= CEPH_MOUNT_NOSHARE;
+			break;
+		case Opt_unsafewriteback:
+			args->flags |= CEPH_MOUNT_UNSAFE_WRITEBACK;
+			break;
+		case Opt_safewriteback:
+			args->flags &= ~CEPH_MOUNT_UNSAFE_WRITEBACK;
+			break;
+
+		case Opt_dirstat:
+			args->flags |= CEPH_MOUNT_DIRSTAT;
+			break;
+		case Opt_nodirstat:
+			args->flags &= ~CEPH_MOUNT_DIRSTAT;
+			break;
+		case Opt_rbytes:
+			args->flags |= CEPH_MOUNT_RBYTES;
+			break;
+		case Opt_norbytes:
+			args->flags &= ~CEPH_MOUNT_RBYTES;
+			break;
+		case Opt_nocrc:
+			args->flags |= CEPH_MOUNT_NOCRC;
+			break;
+
+		default:
+			BUG_ON(token);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * 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->wb_wq = create_workqueue("ceph-writeback");
+	if (client->wb_wq == NULL)
+		goto fail;
+	client->pg_inv_wq = create_workqueue("ceph-pg-invalid");
+	if (client->pg_inv_wq == NULL)
+		goto fail;
+	client->trunc_wq = create_workqueue("ceph-trunc");
+	if (client->trunc_wq == NULL)
+		goto fail;
+
+	/* subsystems */
+	err = ceph_monc_init(&client->monc, client);
+	if (err < 0)
+		return ERR_PTR(err);
+	ceph_mdsc_init(&client->mdsc, client);
+	ceph_osdc_init(&client->osdc, client);
+
+	return client;
+
+fail:
+	return ERR_PTR(-ENOMEM);
+}
+
+static void ceph_destroy_client(struct ceph_client *client)
+{
+	dout(10, "destroy_client %p\n", client);
+
+	/* unmount */
+	ceph_mdsc_stop(&client->mdsc);
+	ceph_monc_stop(&client->monc);
+	ceph_osdc_stop(&client->osdc);
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
+	if (client->client_kobj)
+		kobject_put(client->client_kobj);
+#endif
+	if (client->wb_wq)
+		destroy_workqueue(client->wb_wq);
+	if (client->pg_inv_wq)
+		destroy_workqueue(client->pg_inv_wq);
+	if (client->trunc_wq)
+		destroy_workqueue(client->trunc_wq);
+	if (client->msgr)
+		ceph_messenger_destroy(client->msgr);
+	kfree(client);
+	dout(10, "destroy_client %p done\n", client);
+}
+
+/*
+ * true if we have the mon, osd, and mds maps, and are thus
+ * fully "mounted".
+ */
+static int have_all_maps(struct ceph_client *client)
+{
+	return client->osdc.osdmap && client->osdc.osdmap->epoch &&
+		client->monc.monmap && client->monc.monmap->epoch &&
+		client->mdsc.mdsmap && client->mdsc.mdsmap->m_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;
+	struct ceph_mds_request_head *reqhead;
+	int err;
+	struct dentry *root;
+
+	/* open dir */
+	dout(30, "open_root_inode opening '%s'\n", path);
+	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_OPEN,
+				       1, path, 0, NULL,
+				       NULL, USE_ANY_MDS);
+	if (IS_ERR(req))
+		return ERR_PTR(PTR_ERR(req));
+	req->r_started = started;
+	req->r_timeout = client->mount_args.mount_timeout * HZ;
+	req->r_expected_cap = kmalloc(sizeof(struct ceph_cap), GFP_NOFS);
+	if (!req->r_expected_cap) {
+		root = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+	reqhead = req->r_request->front.iov_base;
+	reqhead->args.open.flags = cpu_to_le32(O_DIRECTORY);
+	reqhead->args.open.mode = 0;
+	err = ceph_mdsc_do_request(mdsc, req);
+	if (err == 0) {
+		root = req->r_last_dentry;
+		dget(root);
+		dout(30, "open_root_inode success, root dentry is %p\n", root);
+	} else
+		root = ERR_PTR(err);
+out:
+	ceph_mdsc_put_request(req);
+	return root;
+}
+
+/*
+ * mount: join the ceph cluster.
+ */
+static int ceph_mount(struct ceph_client *client, struct vfsmount *mnt,
+		      const char *path)
+{
+	struct ceph_entity_addr *myaddr = NULL;
+	struct ceph_msg *mount_msg;
+	struct dentry *root;
+	int err;
+	int request_interval = 5 * HZ;
+	unsigned long timeout = client->mount_args.mount_timeout * HZ;
+	unsigned long started = jiffies;  /* note the start time */
+	int which;
+	unsigned char r;
+
+	dout(10, "mount start\n");
+	mutex_lock(&client->mount_mutex);
+
+	/* initialize the messenger */
+	if (client->msgr == NULL) {
+		if (client->mount_args.flags & CEPH_MOUNT_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->parent = client;
+		client->msgr->dispatch = ceph_dispatch;
+		client->msgr->prepare_pages = ceph_osdc_prepare_pages;
+		client->msgr->peer_reset = ceph_peer_reset;
+	}
+
+	/* send mount request, and wait for mon, mds, and osd maps */
+	while (!have_all_maps(client)) {
+		err = -EIO;
+		if (timeout && time_after_eq(jiffies, started + timeout))
+			goto out;
+		dout(10, "mount sending mount request\n");
+		get_random_bytes(&r, 1);
+		which = r % client->mount_args.num_mon;
+		mount_msg = ceph_msg_new(CEPH_MSG_CLIENT_MOUNT, 0, 0, 0, NULL);
+		if (IS_ERR(mount_msg)) {
+			err = PTR_ERR(mount_msg);
+			goto out;
+		}
+		mount_msg->hdr.dst.name.type =
+			cpu_to_le32(CEPH_ENTITY_TYPE_MON);
+		mount_msg->hdr.dst.name.num = cpu_to_le32(which);
+		mount_msg->hdr.dst.addr = client->mount_args.mon_addr[which];
+
+		ceph_msg_send(client->msgr, mount_msg, 0);
+
+		/* wait */
+		dout(10, "mount sent to mon%d, waiting for maps\n", which);
+		err = wait_event_interruptible_timeout(client->mount_wq,
+						       have_all_maps(client),
+						       request_interval);
+		if (err == -EINTR)
+			goto out;
+	}
+
+	dout(30, "mount opening base mountpoint\n");
+	root = open_root_dentry(client, path, started);
+	if (IS_ERR(root)) {
+		err = PTR_ERR(root);
+		goto out;
+	}
+
+	/*
+	 * Drop the reference we just got, since the VFS doesn't give
+	 * us a reliable way to drop it later when a particular
+	 * vfsmount goes away.  If the directory we just mounted on is
+	 * renamed on the server, we are screwed.
+	 */
+	ceph_put_fmode(ceph_inode(root->d_inode), CEPH_FILE_MODE_PIN);
+
+	mnt->mnt_root = root;
+	mnt->mnt_sb = client->sb;
+	client->mount_state = CEPH_MOUNT_MOUNTED;
+	dout(10, "mount success\n");
+	err = 0;
+
+out:
+	mutex_unlock(&client->mount_mutex);
+	return err;
+}
+
+
+/*
+ * Process an incoming message.
+ *
+ * This should be relatively fast and must not do any work that waits
+ * on other messages to be received.
+ */
+void ceph_dispatch(void *p, struct ceph_msg *msg)
+{
+	struct ceph_client *client = p;
+	int had;
+	int type = le16_to_cpu(msg->hdr.type);
+
+	switch (type) {
+	case CEPH_MSG_MON_MAP:
+		had = client->monc.monmap->epoch ? 1 : 0;
+		handle_monmap(client, msg);
+		if (!had && client->monc.monmap->epoch && have_all_maps(client))
+			wake_up(&client->mount_wq);
+		break;
+
+		/* mon client */
+	case CEPH_MSG_STATFS_REPLY:
+		ceph_monc_handle_statfs_reply(&client->monc, msg);
+		break;
+	case CEPH_MSG_CLIENT_UNMOUNT:
+		ceph_monc_handle_umount(&client->monc, msg);
+		break;
+
+		/* mds client */
+	case CEPH_MSG_MDS_MAP:
+		had = client->mdsc.mdsmap ? 1 : 0;
+		ceph_mdsc_handle_map(&client->mdsc, msg);
+		if (!had && client->mdsc.mdsmap && have_all_maps(client))
+			wake_up(&client->mount_wq);
+		break;
+	case CEPH_MSG_CLIENT_SESSION:
+		ceph_mdsc_handle_session(&client->mdsc, msg);
+		break;
+	case CEPH_MSG_CLIENT_REPLY:
+		ceph_mdsc_handle_reply(&client->mdsc, msg);
+		break;
+	case CEPH_MSG_CLIENT_REQUEST_FORWARD:
+		ceph_mdsc_handle_forward(&client->mdsc, msg);
+		break;
+	case CEPH_MSG_CLIENT_CAPS:
+		ceph_handle_caps(&client->mdsc, msg);
+		break;
+	case CEPH_MSG_CLIENT_SNAP:
+		ceph_handle_snap(&client->mdsc, msg);
+		break;
+	case CEPH_MSG_CLIENT_LEASE:
+		ceph_mdsc_handle_lease(&client->mdsc, msg);
+		break;
+
+		/* osd client */
+	case CEPH_MSG_OSD_MAP:
+		had = client->osdc.osdmap ? 1 : 0;
+		ceph_osdc_handle_map(&client->osdc, msg);
+		if (!had && client->osdc.osdmap && have_all_maps(client))
+			wake_up(&client->mount_wq);
+		break;
+	case CEPH_MSG_OSD_OPREPLY:
+		ceph_osdc_handle_reply(&client->osdc, msg);
+		break;
+
+	default:
+		derr(0, "received unknown message type %d %s\n", type,
+		     ceph_msg_type_name(type));
+	}
+
+	ceph_msg_put(msg);
+}
+
+
+static int ceph_set_super(struct super_block *s, void *data)
+{
+	struct ceph_client *client = data;
+	int ret;
+
+	dout(10, "set_super %p data %p\n", s, data);
+
+	s->s_flags = client->mount_args.sb_flags;
+	s->s_maxbytes = min((u64)MAX_LFS_FILESIZE, CEPH_FILE_MAX_SIZE);
+
+	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(10, "ceph_compare_super %p\n", sb);
+
+	/* either compare fsid, or specified mon_hostname */
+	if (args->flags & CEPH_MOUNT_FSID) {
+		if (!ceph_fsid_equal(&args->fsid, &other->fsid)) {
+			dout(30, "fsid doesn't match\n");
+			return 0;
+		}
+	} else {
+		/* do we share (a) monitor? */
+		for (i = 0; i < args->num_mon; i++)
+			if (ceph_monmap_contains(other->monc.monmap,
+						 &args->mon_addr[i]))
+				break;
+		if (i == args->num_mon) {
+			dout(30, "mon ip not part of monmap\n");
+			return 0;
+		}
+		dout(10, "mon ip matches existing sb %p\n", sb);
+	}
+	if (args->sb_flags != other->mount_args.sb_flags) {
+		dout(30, "flags differ\n");
+		return 0;
+	}
+	return 1;
+}
+
+/*
+ * construct our own bdi so we can control readahead
+ */
+static int ceph_init_bdi(struct super_block *sb, struct ceph_client *client)
+{
+	int err;
+
+	if (client->mount_args.rsize)
+		client->backing_dev_info.ra_pages =
+			(client->mount_args.rsize + PAGE_CACHE_SIZE - 1)
+			>> PAGE_SHIFT;
+
+	if (client->backing_dev_info.ra_pages < (PAGE_CACHE_SIZE >> PAGE_SHIFT))
+		client->backing_dev_info.ra_pages =
+			CEPH_DEFAULT_READ_SIZE >> PAGE_SHIFT;
+
+	err = bdi_init(&client->backing_dev_info);
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
+	if (err < 0)
+		return err;
+
+	err = bdi_register_dev(&client->backing_dev_info, sb->s_dev);
+#endif
+
+	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(25, "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(flags, data, dev_name,
+			       &client->mount_args, &path);
+	if (err < 0)
+		goto out;
+
+	if (client->mount_args.flags & CEPH_MOUNT_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(20, "get_sb got existing client %p\n", client);
+	} else {
+		dout(20, "get_sb using new client %p\n", client);
+
+		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(22, "root ino %llx.%llx\n", ceph_vinop(mnt->mnt_root->d_inode));
+	return 0;
+
+out_splat:
+	up_write(&sb->s_umount);
+	deactivate_super(sb);
+	goto out_final;
+out:
+	ceph_destroy_client(client);
+out_final:
+	dout(25, "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(1, "kill_sb %p\n", s);
+	ceph_mdsc_pre_umount(&client->mdsc);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
+	bdi_unregister(&client->backing_dev_info);
+#endif
+	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,
+};
+
+struct kobject *ceph_kobj;
+
+static int __init init_ceph(void)
+{
+	int ret = 0;
+
+	dout(1, "init_ceph\n");
+
+#ifdef CONFIG_CEPH_BOOKKEEPER
+	ceph_bookkeeper_init();
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
+	ret = -ENOMEM;
+	ceph_kobj = kobject_create_and_add("ceph", fs_kobj);
+	if (!ceph_kobj)
+		goto out;
+#endif
+
+	ret = ceph_proc_init();
+	if (ret < 0)
+		goto out_kobj;
+
+	ret = ceph_msgr_init();
+	if (ret < 0)
+		goto out_proc;
+
+	ret = init_inodecache();
+	if (ret)
+		goto out_msgr;
+
+	ret = register_filesystem(&ceph_fs_type);
+	if (ret)
+		goto out_icache;
+	return 0;
+
+out_icache:
+	destroy_inodecache();
+out_msgr:
+	ceph_msgr_exit();
+out_proc:
+	ceph_proc_cleanup();
+out_kobj:
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
+	kobject_put(ceph_kobj);
+	ceph_kobj = NULL;
+out:
+#endif
+	return ret;
+}
+
+static void __exit exit_ceph(void)
+{
+	dout(1, "exit_ceph\n");
+	unregister_filesystem(&ceph_fs_type);
+	destroy_inodecache();
+	ceph_msgr_exit();
+	ceph_proc_cleanup();
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25)
+	kobject_put(ceph_kobj);
+	ceph_kobj = NULL;
+#endif
+#ifdef CONFIG_CEPH_BOOKKEEPER
+	ceph_bookkeeper_finalize();
+#endif
+}
+
+module_init(init_ceph);
+module_exit(exit_ceph);
+
+MODULE_AUTHOR("Patience Warnick <patience@...dream.net>");
+MODULE_AUTHOR("Sage Weil <sage@...dream.net>");
+MODULE_DESCRIPTION("Ceph filesystem for Linux");
+MODULE_LICENSE("GPL");
-- 
1.5.6.5

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