/*
* Copyright (C) 2005, 2006
* Avishay Traeger (avishay@gmail.com)
* Copyright (C) 2008, 2009
* Boaz Harrosh <bharrosh@panasas.com>
*
* Copyrights for code taken from ext2:
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
* from
* linux/fs/minix/inode.c
* Copyright (C) 1991, 1992 Linus Torvalds
*
* This file is part of exofs.
*
* exofs is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation. Since it is based on ext2, and the only
* valid version of GPL for the Linux kernel is version 2, the only valid
* version of GPL for exofs is version 2.
*
* exofs is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with exofs; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/smp_lock.h>
#include <linux/string.h>
#include <linux/parser.h>
#include <linux/vfs.h>
#include <linux/random.h>
#include <linux/exportfs.h>
#include "exofs.h"
/******************************************************************************
* MOUNT OPTIONS
*****************************************************************************/
/*
* struct to hold what we get from mount options
*/
struct exofs_mountopt {
const char *dev_name;
uint64_t pid;
int timeout;
};
/*
* exofs-specific mount-time options.
*/
enum { Opt_pid, Opt_to, Opt_mkfs, Opt_format, Opt_err };
/*
* Our mount-time options. These should ideally be 64-bit unsigned, but the
* kernel's parsing functions do not currently support that. 32-bit should be
* sufficient for most applications now.
*/
static match_table_t tokens = {
{Opt_pid, "pid=%u"},
{Opt_to, "to=%u"},
{Opt_err, NULL}
};
/*
* The main option parsing method. Also makes sure that all of the mandatory
* mount options were set.
*/
static int parse_options(char *options, struct exofs_mountopt *opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
bool s_pid = false;
EXOFS_DBGMSG("parse_options %s\n", options);
/* defaults */
memset(opts, 0, sizeof(*opts));
opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
while ((p = strsep(&options, ",")) != NULL) {
int token;
char str[32];
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_pid:
if (0 == match_strlcpy(str, &args[0], sizeof(str)))
return -EINVAL;
opts->pid = simple_strtoull(str, NULL, 0);
if (opts->pid < EXOFS_MIN_PID) {
EXOFS_ERR("Partition ID must be >= %u",
EXOFS_MIN_PID);
return -EINVAL;
}
s_pid = 1;
break;
case Opt_to:
if (match_int(&args[0], &option))
return -EINVAL;
if (option <= 0) {
EXOFS_ERR("Timout must be > 0");
return -EINVAL;
}
opts->timeout = option * HZ;
break;
}
}
if (!s_pid) {
EXOFS_ERR("Need to specify the following options:\n");
EXOFS_ERR(" -o pid=pid_no_to_use\n");
return -EINVAL;
}
return 0;
}
/******************************************************************************
* INODE CACHE
*****************************************************************************/
/*
* Our inode cache. Isn't it pretty?
*/
static struct kmem_cache *exofs_inode_cachep;
/*
* Allocate an inode in the cache
*/
static struct inode *exofs_alloc_inode(struct super_block *sb)
{
struct exofs_i_info *oi;
oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
if (!oi)
return NULL;
oi->vfs_inode.i_version = 1;
return &oi->vfs_inode;
}
/*
* Remove an inode from the cache
*/
static void exofs_destroy_inode(struct inode *inode)
{
kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
}
/*
* Initialize the inode
*/
static void exofs_init_once(void *foo)
{
struct exofs_i_info *oi = foo;
inode_init_once(&oi->vfs_inode);
}
/*
* Create and initialize the inode cache
*/
static int init_inodecache(void)
{
exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
sizeof(struct exofs_i_info), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
exofs_init_once);
if (exofs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
/*
* Destroy the inode cache
*/
static void destroy_inodecache(void)
{
kmem_cache_destroy(exofs_inode_cachep);
}
/******************************************************************************
* SUPERBLOCK FUNCTIONS
*****************************************************************************/
static const struct super_operations exofs_sops;
static const struct export_operations exofs_export_ops;
/*
* Write the superblock to the OSD
*/
int exofs_sync_fs(struct super_block *sb, int wait)
{
struct exofs_sb_info *sbi;
struct exofs_fscb *fscb;
struct osd_request *or;
struct osd_obj_id obj;
int ret = -ENOMEM;
fscb = kzalloc(sizeof(struct exofs_fscb), GFP_KERNEL);
if (!fscb) {
EXOFS_ERR("exofs_write_super: memory allocation failed.\n");
return -ENOMEM;
}
lock_super(sb);
lock_kernel();
sbi = sb->s_fs_info;
fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
fscb->s_numfiles = cpu_to_le32(sbi->s_numfiles);
fscb->s_magic = cpu_to_le16(sb->s_magic);
fscb->s_newfs = 0;
or = osd_start_request(sbi->s_dev, GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("exofs_write_super: osd_start_request failed.\n");
goto out;
}
obj.partition = sbi->s_pid;
obj.id = EXOFS_SUPER_ID;
ret = osd_req_write_kern(or, &obj, 0, fscb, sizeof(*fscb));
if (unlikely(ret)) {
EXOFS_ERR("exofs_write_super: osd_req_write_kern failed.\n");
goto out;
}
ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
if (unlikely(ret)) {
EXOFS_ERR("exofs_write_super: exofs_sync_op failed.\n");
goto out;
}
sb->s_dirt = 0;
out:
if (or)
osd_end_request(or);
unlock_kernel();
unlock_super(sb);
kfree(fscb);
return ret;
}
static void exofs_write_super(struct super_block *sb)
{
if (!(sb->s_flags & MS_RDONLY))
exofs_sync_fs(sb, 1);
else
sb->s_dirt = 0;
}
/*
* This function is called when the vfs is freeing the superblock. We just
* need to free our own part.
*/
static void exofs_put_super(struct super_block *sb)
{
int num_pend;
struct exofs_sb_info *sbi = sb->s_fs_info;
lock_kernel();
if (sb->s_dirt)
exofs_write_super(sb);
/* make sure there are no pending commands */
for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
num_pend = atomic_read(&sbi->s_curr_pending)) {
wait_queue_head_t wq;
init_waitqueue_head(&wq);
wait_event_timeout(wq,
(atomic_read(&sbi->s_curr_pending) == 0),
msecs_to_jiffies(100));
}
osduld_put_device(sbi->s_dev);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
unlock_kernel();
}
/*
* Read the superblock from the OSD and fill in the fields
*/
static int exofs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *root;
struct exofs_mountopt *opts = data;
struct exofs_sb_info *sbi; /*extended info */
struct exofs_fscb fscb; /*on-disk superblock info */
struct osd_request *or = NULL;
struct osd_obj_id obj;
int ret;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
/* use mount options to fill superblock */
sbi->s_dev = osduld_path_lookup(opts->dev_name);
if (IS_ERR(sbi->s_dev)) {
ret = PTR_ERR(sbi->s_dev);
sbi->s_dev = NULL;
goto free_sbi;
}
sbi->s_pid = opts->pid;
sbi->s_timeout = opts->timeout;
/* fill in some other data by hand */
memset(sb->s_id, 0, sizeof(sb->s_id));
strcpy(sb->s_id, "exofs");
sb->s_blocksize = EXOFS_BLKSIZE;
sb->s_blocksize_bits = EXOFS_BLKSHIFT;
sb->s_maxbytes = MAX_LFS_FILESIZE;
atomic_set(&sbi->s_curr_pending, 0);
sb->s_bdev = NULL;
sb->s_dev = 0;
/* read data from on-disk superblock object */
obj.partition = sbi->s_pid;
obj.id = EXOFS_SUPER_ID;
exofs_make_credential(sbi->s_cred, &obj);
or = osd_start_request(sbi->s_dev, GFP_KERNEL);
if (unlikely(!or)) {
if (!silent)
EXOFS_ERR(
"exofs_fill_super: osd_start_request failed.\n");
ret = -ENOMEM;
goto free_sbi;
}
ret = osd_req_read_kern(or, &obj, 0, &fscb, sizeof(fscb));
if (unlikely(ret)) {
if (!silent)
EXOFS_ERR(
"exofs_fill_super: osd_req_read_kern failed.\n");
ret = -ENOMEM;
goto free_sbi;
}
ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
if (unlikely(ret)) {
if (!silent)
EXOFS_ERR("exofs_fill_super: exofs_sync_op failed.\n");
ret = -EIO;
goto free_sbi;
}
sb->s_magic = le16_to_cpu(fscb.s_magic);
sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
/* make sure what we read from the object store is correct */
if (sb->s_magic != EXOFS_SUPER_MAGIC) {
if (!silent)
EXOFS_ERR("ERROR: Bad magic value\n");
ret = -EINVAL;
goto free_sbi;
}
/* start generation numbers from a random point */
get_random_bytes(&sbi->s_next_generation, sizeof(u32));
spin_lock_init(&sbi->s_next_gen_lock);
/* set up operation vectors */
sb->s_op = &exofs_sops;
sb->s_export_op = &exofs_export_ops;
root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
if (IS_ERR(root)) {
EXOFS_ERR("ERROR: exofs_iget failed\n");
ret = PTR_ERR(root);
goto free_sbi;
}
sb->s_root = d_alloc_root(root);
if (!sb->s_root) {
iput(root);
EXOFS_ERR("ERROR: get root inode failed\n");
ret = -ENOMEM;
goto free_sbi;
}
if (!S_ISDIR(root->i_mode)) {
dput(sb->s_root);
sb->s_root = NULL;
EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
root->i_mode);
ret = -EINVAL;
goto free_sbi;
}
ret = 0;
out:
if (or)
osd_end_request(or);
return ret;
free_sbi:
osduld_put_device(sbi->s_dev); /* NULL safe */
kfree(sbi);
goto out;
}
/*
* Set up the superblock (calls exofs_fill_super eventually)
*/
static int exofs_get_sb(struct file_system_type *type,
int flags, const char *dev_name,
void *data, struct vfsmount *mnt)
{
struct exofs_mountopt opts;
int ret;
ret = parse_options(data, &opts);
if (ret)
return ret;
opts.dev_name = dev_name;
return get_sb_nodev(type, flags, &opts, exofs_fill_super, mnt);
}
/*
* Return information about the file system state in the buffer. This is used
* by the 'df' command, for example.
*/
static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct exofs_sb_info *sbi = sb->s_fs_info;
struct osd_obj_id obj = {sbi->s_pid, 0};
struct osd_attr attrs[] = {
ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
};
uint64_t capacity = ULLONG_MAX;
uint64_t used = ULLONG_MAX;
struct osd_request *or;
uint8_t cred_a[OSD_CAP_LEN];
int ret;
/* get used/capacity attributes */
exofs_make_credential(cred_a, &obj);
or = osd_start_request(sbi->s_dev, GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_DBGMSG("exofs_statfs: osd_start_request failed.\n");
return -ENOMEM;
}
osd_req_get_attributes(or, &obj);
osd_req_add_get_attr_list(or, attrs, ARRAY_SIZE(attrs));
ret = exofs_sync_op(or, sbi->s_timeout, cred_a);
if (unlikely(ret))
goto out;
ret = extract_attr_from_req(or, &attrs[0]);
if (likely(!ret))
capacity = get_unaligned_be64(attrs[0].val_ptr);
else
EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
ret = extract_attr_from_req(or, &attrs[1]);
if (likely(!ret))
used = get_unaligned_be64(attrs[1].val_ptr);
else
EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
/* fill in the stats buffer */
buf->f_type = EXOFS_SUPER_MAGIC;
buf->f_bsize = EXOFS_BLKSIZE;
buf->f_blocks = (capacity >> EXOFS_BLKSHIFT);
buf->f_bfree = ((capacity - used) >> EXOFS_BLKSHIFT);
buf->f_bavail = buf->f_bfree;
buf->f_files = sbi->s_numfiles;
buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
buf->f_namelen = EXOFS_NAME_LEN;
out:
osd_end_request(or);
return ret;
}
static const struct super_operations exofs_sops = {
.alloc_inode = exofs_alloc_inode,
.destroy_inode = exofs_destroy_inode,
.write_inode = exofs_write_inode,
.delete_inode = exofs_delete_inode,
.put_super = exofs_put_super,
.write_super = exofs_write_super,
.sync_fs = exofs_sync_fs,
.statfs = exofs_statfs,
};
/******************************************************************************
* EXPORT OPERATIONS
*****************************************************************************/
struct dentry *exofs_get_parent(struct dentry *child)
{
unsigned long ino = exofs_parent_ino(child);
if (!ino)
return NULL;
return d_obtain_alias(exofs_iget(child->d_inode->i_sb, ino));
}
static struct inode *exofs_nfs_get_inode(struct super_block *sb,
u64 ino, u32 generation)
{
struct inode *inode;
inode = exofs_iget(sb, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
if (generation && inode->i_generation != generation) {
/* we didn't find the right inode.. */
iput(inode);
return ERR_PTR(-ESTALE);
}
return inode;
}
static struct dentry *exofs_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
exofs_nfs_get_inode);
}
static struct dentry *exofs_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
return generic_fh_to_parent(sb, fid, fh_len, fh_type,
exofs_nfs_get_inode);
}
static const struct export_operations exofs_export_ops = {
.fh_to_dentry = exofs_fh_to_dentry,
.fh_to_parent = exofs_fh_to_parent,
.get_parent = exofs_get_parent,
};
/******************************************************************************
* INSMOD/RMMOD
*****************************************************************************/
/*
* struct that describes this file system
*/
static struct file_system_type exofs_type = {
.owner = THIS_MODULE,
.name = "exofs",
.get_sb = exofs_get_sb,
.kill_sb = generic_shutdown_super,
};
static int __init init_exofs(void)
{
int err;
err = init_inodecache();
if (err)
goto out;
err = register_filesystem(&exofs_type);
if (err)
goto out_d;
return 0;
out_d:
destroy_inodecache();
out:
return err;
}
static void __exit exit_exofs(void)
{
unregister_filesystem(&exofs_type);
destroy_inodecache();
}
MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
MODULE_DESCRIPTION("exofs");
MODULE_LICENSE("GPL");
module_init(init_exofs)
module_exit(exit_exofs)
