linux/fs/ceph/super.c
Alex Elder c98f533c94 ceph: let path portion of mount "device" be optional
A recent change to /sbin/mountall causes any trailing '/' character
in the "device" (or fs_spec) field in /etc/fstab to be stripped.  As
a result, an entry for a ceph mount that intends to mount the root
of the name space ends up with now path portion, and the ceph mount
option processing code rejects this.

That is, an entry in /etc/fstab like:
    cephserver:port:/ /mnt ceph defaults 0 0
provides to the ceph code just "cephserver:port:" as the "device,"
and that gets rejected.

Although this is a bug in /sbin/mountall, we can have the ceph mount
code support an empty/nonexistent path, interpreting it to mean the
root of the name space.

RFC 5952 offers recommendations for how to express IPv6 addresses,
and recommends the usage found in RFC 3986 (which specifies the
format for URI's) for representing both IPv4 and IPv6 addresses that
include port numbers.  (See in particular the definition of
"authority" found in the Appendix of RFC 3986.)

According to those standards, no host specification will ever
contain a '/' character.  As a result, it is sufficient to scan a
provided "device" from an /etc/fstab entry for the first '/'
character, and if it's found, treat that as the beginning of the
path.  If no '/' character is present, we can treat the entire
string as the monitor host specification(s), and assume the path
to be the root of the name space.  We'll still require a ':' to
separate the host portion from the (possibly empty) path portion.

This means that we can more formally define how ceph will interpret
the "device" it's provided when processing a mount request:

    "device" will look like:
        <server_spec>[,<server_spec>...]:[<path>]
    where
        <server_spec> is <ip>[:<port>]
        <path> is optional, but if present must begin with '/'

This addresses http://tracker.newdream.net/issues/2919

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
2012-10-01 14:30:49 -05:00

989 lines
24 KiB
C

#include <linux/ceph/ceph_debug.h>
#include <linux/backing-dev.h>
#include <linux/ctype.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/sched.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/statfs.h>
#include <linux/string.h>
#include "super.h"
#include "mds_client.h"
#include <linux/ceph/ceph_features.h>
#include <linux/ceph/decode.h>
#include <linux/ceph/mon_client.h>
#include <linux/ceph/auth.h>
#include <linux/ceph/debugfs.h>
/*
* Ceph superblock operations
*
* Handle the basics of mounting, unmounting.
*/
/*
* super ops
*/
static void ceph_put_super(struct super_block *s)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(s);
dout("put_super\n");
ceph_mdsc_close_sessions(fsc->mdsc);
/*
* ensure we release the bdi before put_anon_super releases
* the device name.
*/
if (s->s_bdi == &fsc->backing_dev_info) {
bdi_unregister(&fsc->backing_dev_info);
s->s_bdi = NULL;
}
return;
}
static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct ceph_fs_client *fsc = ceph_inode_to_client(dentry->d_inode);
struct ceph_monmap *monmap = fsc->client->monc.monmap;
struct ceph_statfs st;
u64 fsid;
int err;
dout("statfs\n");
err = ceph_monc_do_statfs(&fsc->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_avail) >> (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 = NAME_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_sync_fs(struct super_block *sb, int wait)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
if (!wait) {
dout("sync_fs (non-blocking)\n");
ceph_flush_dirty_caps(fsc->mdsc);
dout("sync_fs (non-blocking) done\n");
return 0;
}
dout("sync_fs (blocking)\n");
ceph_osdc_sync(&fsc->client->osdc);
ceph_mdsc_sync(fsc->mdsc);
dout("sync_fs (blocking) done\n");
return 0;
}
/*
* mount options
*/
enum {
Opt_wsize,
Opt_rsize,
Opt_rasize,
Opt_caps_wanted_delay_min,
Opt_caps_wanted_delay_max,
Opt_cap_release_safety,
Opt_readdir_max_entries,
Opt_readdir_max_bytes,
Opt_congestion_kb,
Opt_last_int,
/* int args above */
Opt_snapdirname,
Opt_last_string,
/* string args above */
Opt_dirstat,
Opt_nodirstat,
Opt_rbytes,
Opt_norbytes,
Opt_asyncreaddir,
Opt_noasyncreaddir,
Opt_dcache,
Opt_nodcache,
Opt_ino32,
Opt_noino32,
};
static match_table_t fsopt_tokens = {
{Opt_wsize, "wsize=%d"},
{Opt_rsize, "rsize=%d"},
{Opt_rasize, "rasize=%d"},
{Opt_caps_wanted_delay_min, "caps_wanted_delay_min=%d"},
{Opt_caps_wanted_delay_max, "caps_wanted_delay_max=%d"},
{Opt_cap_release_safety, "cap_release_safety=%d"},
{Opt_readdir_max_entries, "readdir_max_entries=%d"},
{Opt_readdir_max_bytes, "readdir_max_bytes=%d"},
{Opt_congestion_kb, "write_congestion_kb=%d"},
/* int args above */
{Opt_snapdirname, "snapdirname=%s"},
/* string args above */
{Opt_dirstat, "dirstat"},
{Opt_nodirstat, "nodirstat"},
{Opt_rbytes, "rbytes"},
{Opt_norbytes, "norbytes"},
{Opt_asyncreaddir, "asyncreaddir"},
{Opt_noasyncreaddir, "noasyncreaddir"},
{Opt_dcache, "dcache"},
{Opt_nodcache, "nodcache"},
{Opt_ino32, "ino32"},
{Opt_noino32, "noino32"},
{-1, NULL}
};
static int parse_fsopt_token(char *c, void *private)
{
struct ceph_mount_options *fsopt = private;
substring_t argstr[MAX_OPT_ARGS];
int token, intval, ret;
token = match_token((char *)c, fsopt_tokens, argstr);
if (token < 0)
return -EINVAL;
if (token < Opt_last_int) {
ret = match_int(&argstr[0], &intval);
if (ret < 0) {
pr_err("bad mount option arg (not int) "
"at '%s'\n", c);
return ret;
}
dout("got int token %d val %d\n", token, intval);
} else if (token > Opt_last_int && token < Opt_last_string) {
dout("got string token %d val %s\n", token,
argstr[0].from);
} else {
dout("got token %d\n", token);
}
switch (token) {
case Opt_snapdirname:
kfree(fsopt->snapdir_name);
fsopt->snapdir_name = kstrndup(argstr[0].from,
argstr[0].to-argstr[0].from,
GFP_KERNEL);
if (!fsopt->snapdir_name)
return -ENOMEM;
break;
/* misc */
case Opt_wsize:
fsopt->wsize = intval;
break;
case Opt_rsize:
fsopt->rsize = intval;
break;
case Opt_rasize:
fsopt->rasize = intval;
break;
case Opt_caps_wanted_delay_min:
fsopt->caps_wanted_delay_min = intval;
break;
case Opt_caps_wanted_delay_max:
fsopt->caps_wanted_delay_max = intval;
break;
case Opt_readdir_max_entries:
fsopt->max_readdir = intval;
break;
case Opt_readdir_max_bytes:
fsopt->max_readdir_bytes = intval;
break;
case Opt_congestion_kb:
fsopt->congestion_kb = intval;
break;
case Opt_dirstat:
fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
break;
case Opt_nodirstat:
fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
break;
case Opt_rbytes:
fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
break;
case Opt_norbytes:
fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
break;
case Opt_asyncreaddir:
fsopt->flags &= ~CEPH_MOUNT_OPT_NOASYNCREADDIR;
break;
case Opt_noasyncreaddir:
fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
break;
case Opt_dcache:
fsopt->flags |= CEPH_MOUNT_OPT_DCACHE;
break;
case Opt_nodcache:
fsopt->flags &= ~CEPH_MOUNT_OPT_DCACHE;
break;
case Opt_ino32:
fsopt->flags |= CEPH_MOUNT_OPT_INO32;
break;
case Opt_noino32:
fsopt->flags &= ~CEPH_MOUNT_OPT_INO32;
break;
default:
BUG_ON(token);
}
return 0;
}
static void destroy_mount_options(struct ceph_mount_options *args)
{
dout("destroy_mount_options %p\n", args);
kfree(args->snapdir_name);
kfree(args);
}
static int strcmp_null(const char *s1, const char *s2)
{
if (!s1 && !s2)
return 0;
if (s1 && !s2)
return -1;
if (!s1 && s2)
return 1;
return strcmp(s1, s2);
}
static int compare_mount_options(struct ceph_mount_options *new_fsopt,
struct ceph_options *new_opt,
struct ceph_fs_client *fsc)
{
struct ceph_mount_options *fsopt1 = new_fsopt;
struct ceph_mount_options *fsopt2 = fsc->mount_options;
int ofs = offsetof(struct ceph_mount_options, snapdir_name);
int ret;
ret = memcmp(fsopt1, fsopt2, ofs);
if (ret)
return ret;
ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
if (ret)
return ret;
return ceph_compare_options(new_opt, fsc->client);
}
static int parse_mount_options(struct ceph_mount_options **pfsopt,
struct ceph_options **popt,
int flags, char *options,
const char *dev_name,
const char **path)
{
struct ceph_mount_options *fsopt;
const char *dev_name_end;
int err;
if (!dev_name || !*dev_name)
return -EINVAL;
fsopt = kzalloc(sizeof(*fsopt), GFP_KERNEL);
if (!fsopt)
return -ENOMEM;
dout("parse_mount_options %p, dev_name '%s'\n", fsopt, dev_name);
fsopt->sb_flags = flags;
fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
fsopt->rsize = CEPH_RSIZE_DEFAULT;
fsopt->rasize = CEPH_RASIZE_DEFAULT;
fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
fsopt->congestion_kb = default_congestion_kb();
/*
* Distinguish the server list from the path in "dev_name".
* Internally we do not include the leading '/' in the path.
*
* "dev_name" will look like:
* <server_spec>[,<server_spec>...]:[<path>]
* where
* <server_spec> is <ip>[:<port>]
* <path> is optional, but if present must begin with '/'
*/
dev_name_end = strchr(dev_name, '/');
if (dev_name_end) {
/* skip over leading '/' for path */
*path = dev_name_end + 1;
} else {
/* path is empty */
dev_name_end = dev_name + strlen(dev_name);
*path = dev_name_end;
}
err = -EINVAL;
dev_name_end--; /* back up to ':' separator */
if (*dev_name_end != ':') {
pr_err("device name is missing path (no : separator in %s)\n",
dev_name);
goto out;
}
dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
dout("server path '%s'\n", *path);
*popt = ceph_parse_options(options, dev_name, dev_name_end,
parse_fsopt_token, (void *)fsopt);
if (IS_ERR(*popt)) {
err = PTR_ERR(*popt);
goto out;
}
/* success */
*pfsopt = fsopt;
return 0;
out:
destroy_mount_options(fsopt);
return err;
}
/**
* ceph_show_options - Show mount options in /proc/mounts
* @m: seq_file to write to
* @root: root of that (sub)tree
*/
static int ceph_show_options(struct seq_file *m, struct dentry *root)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(root->d_sb);
struct ceph_mount_options *fsopt = fsc->mount_options;
struct ceph_options *opt = fsc->client->options;
if (opt->flags & CEPH_OPT_FSID)
seq_printf(m, ",fsid=%pU", &opt->fsid);
if (opt->flags & CEPH_OPT_NOSHARE)
seq_puts(m, ",noshare");
if (opt->flags & CEPH_OPT_NOCRC)
seq_puts(m, ",nocrc");
if (opt->name)
seq_printf(m, ",name=%s", opt->name);
if (opt->key)
seq_puts(m, ",secret=<hidden>");
if (opt->mount_timeout != CEPH_MOUNT_TIMEOUT_DEFAULT)
seq_printf(m, ",mount_timeout=%d", opt->mount_timeout);
if (opt->osd_idle_ttl != CEPH_OSD_IDLE_TTL_DEFAULT)
seq_printf(m, ",osd_idle_ttl=%d", opt->osd_idle_ttl);
if (opt->osd_timeout != CEPH_OSD_TIMEOUT_DEFAULT)
seq_printf(m, ",osdtimeout=%d", opt->osd_timeout);
if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
seq_printf(m, ",osdkeepalivetimeout=%d",
opt->osd_keepalive_timeout);
if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
seq_puts(m, ",dirstat");
if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES) == 0)
seq_puts(m, ",norbytes");
if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
seq_puts(m, ",noasyncreaddir");
if (fsopt->flags & CEPH_MOUNT_OPT_DCACHE)
seq_puts(m, ",dcache");
else
seq_puts(m, ",nodcache");
if (fsopt->wsize)
seq_printf(m, ",wsize=%d", fsopt->wsize);
if (fsopt->rsize != CEPH_RSIZE_DEFAULT)
seq_printf(m, ",rsize=%d", fsopt->rsize);
if (fsopt->rasize != CEPH_RASIZE_DEFAULT)
seq_printf(m, ",rasize=%d", fsopt->rasize);
if (fsopt->congestion_kb != default_congestion_kb())
seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
seq_printf(m, ",caps_wanted_delay_min=%d",
fsopt->caps_wanted_delay_min);
if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
seq_printf(m, ",caps_wanted_delay_max=%d",
fsopt->caps_wanted_delay_max);
if (fsopt->cap_release_safety != CEPH_CAP_RELEASE_SAFETY_DEFAULT)
seq_printf(m, ",cap_release_safety=%d",
fsopt->cap_release_safety);
if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
seq_printf(m, ",readdir_max_entries=%d", fsopt->max_readdir);
if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
seq_printf(m, ",snapdirname=%s", fsopt->snapdir_name);
return 0;
}
/*
* handle any mon messages the standard library doesn't understand.
* return error if we don't either.
*/
static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
{
struct ceph_fs_client *fsc = client->private;
int type = le16_to_cpu(msg->hdr.type);
switch (type) {
case CEPH_MSG_MDS_MAP:
ceph_mdsc_handle_map(fsc->mdsc, msg);
return 0;
default:
return -1;
}
}
/*
* create a new fs client
*/
static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
struct ceph_options *opt)
{
struct ceph_fs_client *fsc;
const unsigned supported_features =
CEPH_FEATURE_FLOCK |
CEPH_FEATURE_DIRLAYOUTHASH;
const unsigned required_features = 0;
int err = -ENOMEM;
fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
if (!fsc)
return ERR_PTR(-ENOMEM);
fsc->client = ceph_create_client(opt, fsc, supported_features,
required_features);
if (IS_ERR(fsc->client)) {
err = PTR_ERR(fsc->client);
goto fail;
}
fsc->client->extra_mon_dispatch = extra_mon_dispatch;
fsc->client->monc.want_mdsmap = 1;
fsc->mount_options = fsopt;
fsc->sb = NULL;
fsc->mount_state = CEPH_MOUNT_MOUNTING;
atomic_long_set(&fsc->writeback_count, 0);
err = bdi_init(&fsc->backing_dev_info);
if (err < 0)
goto fail_client;
err = -ENOMEM;
/*
* The number of concurrent works can be high but they don't need
* to be processed in parallel, limit concurrency.
*/
fsc->wb_wq = alloc_workqueue("ceph-writeback", 0, 1);
if (fsc->wb_wq == NULL)
goto fail_bdi;
fsc->pg_inv_wq = alloc_workqueue("ceph-pg-invalid", 0, 1);
if (fsc->pg_inv_wq == NULL)
goto fail_wb_wq;
fsc->trunc_wq = alloc_workqueue("ceph-trunc", 0, 1);
if (fsc->trunc_wq == NULL)
goto fail_pg_inv_wq;
/* set up mempools */
err = -ENOMEM;
fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10,
fsc->mount_options->wsize >> PAGE_CACHE_SHIFT);
if (!fsc->wb_pagevec_pool)
goto fail_trunc_wq;
/* caps */
fsc->min_caps = fsopt->max_readdir;
return fsc;
fail_trunc_wq:
destroy_workqueue(fsc->trunc_wq);
fail_pg_inv_wq:
destroy_workqueue(fsc->pg_inv_wq);
fail_wb_wq:
destroy_workqueue(fsc->wb_wq);
fail_bdi:
bdi_destroy(&fsc->backing_dev_info);
fail_client:
ceph_destroy_client(fsc->client);
fail:
kfree(fsc);
return ERR_PTR(err);
}
static void destroy_fs_client(struct ceph_fs_client *fsc)
{
dout("destroy_fs_client %p\n", fsc);
destroy_workqueue(fsc->wb_wq);
destroy_workqueue(fsc->pg_inv_wq);
destroy_workqueue(fsc->trunc_wq);
bdi_destroy(&fsc->backing_dev_info);
mempool_destroy(fsc->wb_pagevec_pool);
destroy_mount_options(fsc->mount_options);
ceph_fs_debugfs_cleanup(fsc);
ceph_destroy_client(fsc->client);
kfree(fsc);
dout("destroy_fs_client %p done\n", fsc);
}
/*
* 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_fs_client *fsc = ceph_sb_to_client(sb);
dout("ceph_umount_begin - starting forced umount\n");
if (!fsc)
return;
fsc->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_sync_fs,
.put_super = ceph_put_super,
.show_options = ceph_show_options,
.statfs = ceph_statfs,
.umount_begin = ceph_umount_begin,
};
/*
* 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_fs_client *fsc,
const char *path,
unsigned long started)
{
struct ceph_mds_client *mdsc = fsc->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_CAST(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 = fsc->client->options->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) {
struct inode *inode = req->r_target_inode;
req->r_target_inode = NULL;
dout("open_root_inode success\n");
if (ceph_ino(inode) == CEPH_INO_ROOT &&
fsc->sb->s_root == NULL) {
root = d_make_root(inode);
if (!root) {
root = ERR_PTR(-ENOMEM);
goto out;
}
} else {
root = d_obtain_alias(inode);
}
ceph_init_dentry(root);
dout("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, and open root directory.
*/
static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
const char *path)
{
int err;
unsigned long started = jiffies; /* note the start time */
struct dentry *root;
int first = 0; /* first vfsmount for this super_block */
dout("mount start\n");
mutex_lock(&fsc->client->mount_mutex);
err = __ceph_open_session(fsc->client, started);
if (err < 0)
goto out;
dout("mount opening root\n");
root = open_root_dentry(fsc, "", started);
if (IS_ERR(root)) {
err = PTR_ERR(root);
goto out;
}
if (fsc->sb->s_root) {
dput(root);
} else {
fsc->sb->s_root = root;
first = 1;
err = ceph_fs_debugfs_init(fsc);
if (err < 0)
goto fail;
}
if (path[0] == 0) {
dget(root);
} else {
dout("mount opening base mountpoint\n");
root = open_root_dentry(fsc, path, started);
if (IS_ERR(root)) {
err = PTR_ERR(root);
goto fail;
}
}
fsc->mount_state = CEPH_MOUNT_MOUNTED;
dout("mount success\n");
mutex_unlock(&fsc->client->mount_mutex);
return root;
out:
mutex_unlock(&fsc->client->mount_mutex);
return ERR_PTR(err);
fail:
if (first) {
dput(fsc->sb->s_root);
fsc->sb->s_root = NULL;
}
goto out;
}
static int ceph_set_super(struct super_block *s, void *data)
{
struct ceph_fs_client *fsc = data;
int ret;
dout("set_super %p data %p\n", s, data);
s->s_flags = fsc->mount_options->sb_flags;
s->s_maxbytes = 1ULL << 40; /* temp value until we get mdsmap */
s->s_fs_info = fsc;
fsc->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;
fsc->sb = NULL;
return ret;
}
/*
* share superblock if same fs AND options
*/
static int ceph_compare_super(struct super_block *sb, void *data)
{
struct ceph_fs_client *new = data;
struct ceph_mount_options *fsopt = new->mount_options;
struct ceph_options *opt = new->client->options;
struct ceph_fs_client *other = ceph_sb_to_client(sb);
dout("ceph_compare_super %p\n", sb);
if (compare_mount_options(fsopt, opt, other)) {
dout("monitor(s)/mount options don't match\n");
return 0;
}
if ((opt->flags & CEPH_OPT_FSID) &&
ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
dout("fsid doesn't match\n");
return 0;
}
if (fsopt->sb_flags != other->mount_options->sb_flags) {
dout("flags differ\n");
return 0;
}
return 1;
}
/*
* construct our own bdi so we can control readahead, etc.
*/
static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
static int ceph_register_bdi(struct super_block *sb,
struct ceph_fs_client *fsc)
{
int err;
/* set ra_pages based on rasize mount option? */
if (fsc->mount_options->rasize >= PAGE_CACHE_SIZE)
fsc->backing_dev_info.ra_pages =
(fsc->mount_options->rasize + PAGE_CACHE_SIZE - 1)
>> PAGE_SHIFT;
else
fsc->backing_dev_info.ra_pages =
default_backing_dev_info.ra_pages;
err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%d",
atomic_long_inc_return(&bdi_seq));
if (!err)
sb->s_bdi = &fsc->backing_dev_info;
return err;
}
static struct dentry *ceph_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
struct super_block *sb;
struct ceph_fs_client *fsc;
struct dentry *res;
int err;
int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
const char *path = NULL;
struct ceph_mount_options *fsopt = NULL;
struct ceph_options *opt = NULL;
dout("ceph_mount\n");
err = parse_mount_options(&fsopt, &opt, flags, data, dev_name, &path);
if (err < 0) {
res = ERR_PTR(err);
goto out_final;
}
/* create client (which we may/may not use) */
fsc = create_fs_client(fsopt, opt);
if (IS_ERR(fsc)) {
res = ERR_CAST(fsc);
destroy_mount_options(fsopt);
ceph_destroy_options(opt);
goto out_final;
}
err = ceph_mdsc_init(fsc);
if (err < 0) {
res = ERR_PTR(err);
goto out;
}
if (ceph_test_opt(fsc->client, NOSHARE))
compare_super = NULL;
sb = sget(fs_type, compare_super, ceph_set_super, flags, fsc);
if (IS_ERR(sb)) {
res = ERR_CAST(sb);
goto out;
}
if (ceph_sb_to_client(sb) != fsc) {
ceph_mdsc_destroy(fsc);
destroy_fs_client(fsc);
fsc = ceph_sb_to_client(sb);
dout("get_sb got existing client %p\n", fsc);
} else {
dout("get_sb using new client %p\n", fsc);
err = ceph_register_bdi(sb, fsc);
if (err < 0) {
res = ERR_PTR(err);
goto out_splat;
}
}
res = ceph_real_mount(fsc, path);
if (IS_ERR(res))
goto out_splat;
dout("root %p inode %p ino %llx.%llx\n", res,
res->d_inode, ceph_vinop(res->d_inode));
return res;
out_splat:
ceph_mdsc_close_sessions(fsc->mdsc);
deactivate_locked_super(sb);
goto out_final;
out:
ceph_mdsc_destroy(fsc);
destroy_fs_client(fsc);
out_final:
dout("ceph_mount fail %ld\n", PTR_ERR(res));
return res;
}
static void ceph_kill_sb(struct super_block *s)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(s);
dout("kill_sb %p\n", s);
ceph_mdsc_pre_umount(fsc->mdsc);
kill_anon_super(s); /* will call put_super after sb is r/o */
ceph_mdsc_destroy(fsc);
destroy_fs_client(fsc);
}
static struct file_system_type ceph_fs_type = {
.owner = THIS_MODULE,
.name = "ceph",
.mount = ceph_mount,
.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 = init_caches();
if (ret)
goto out;
ceph_xattr_init();
ret = register_filesystem(&ceph_fs_type);
if (ret)
goto out_icache;
pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
return 0;
out_icache:
ceph_xattr_exit();
destroy_caches();
out:
return ret;
}
static void __exit exit_ceph(void)
{
dout("exit_ceph\n");
unregister_filesystem(&ceph_fs_type);
ceph_xattr_exit();
destroy_caches();
}
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");