#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/cred.h>
#include <linux/buffer_head.h>
#include <linux/vmalloc.h>
#include <linux/writeback.h>
#include <linux/seq_file.h>
#include <linux/crc-itu-t.h>
#include <linux/fs_struct.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include "omfs.h"
MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
MODULE_LICENSE("GPL");
struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
{
struct omfs_sb_info *sbi = OMFS_SB(sb);
if (block >= sbi->s_num_blocks)
return NULL;
return sb_bread(sb, clus_to_blk(sbi, block));
}
struct inode *omfs_new_inode(struct inode *dir, umode_t mode)
{
struct inode *inode;
u64 new_block;
int err;
int len;
struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
inode = new_inode(dir->i_sb);
if (!inode)
return ERR_PTR(-ENOMEM);
err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
&new_block, &len);
if (err)
goto fail;
inode->i_ino = new_block;
inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
inode->i_mapping->a_ops = &omfs_aops;
simple_inode_init_ts(inode);
switch (mode & S_IFMT) {
case S_IFDIR:
inode->i_op = &omfs_dir_inops;
inode->i_fop = &omfs_dir_operations;
inode->i_size = sbi->s_sys_blocksize;
inc_nlink(inode);
break;
case S_IFREG:
inode->i_op = &omfs_file_inops;
inode->i_fop = &omfs_file_operations;
inode->i_size = 0;
break;
}
insert_inode_hash(inode);
mark_inode_dirty(inode);
return inode;
fail:
make_bad_inode(inode);
iput(inode);
return ERR_PTR(err);
}
static void omfs_update_checksums(struct omfs_inode *oi)
{
int xor, i, ofs = 0, count;
u16 crc = 0;
unsigned char *ptr = (unsigned char *) oi;
count = be32_to_cpu(oi->i_head.h_body_size);
ofs = sizeof(struct omfs_header);
crc = crc_itu_t(crc, ptr + ofs, count);
oi->i_head.h_crc = cpu_to_be16(crc);
xor = ptr[0];
for (i = 1; i < OMFS_XOR_COUNT; i++)
xor ^= ptr[i];
oi->i_head.h_check_xor = xor;
}
static int __omfs_write_inode(struct inode *inode, int wait)
{
struct omfs_inode *oi;
struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
struct buffer_head *bh, *bh2;
u64 ctime;
int i;
int ret = -EIO;
int sync_failed = 0;
bh = omfs_bread(inode->i_sb, inode->i_ino);
if (!bh)
goto out;
oi = (struct omfs_inode *) bh->b_data;
oi->i_head.h_self = cpu_to_be64(inode->i_ino);
if (S_ISDIR(inode->i_mode))
oi->i_type = OMFS_DIR;
else if (S_ISREG(inode->i_mode))
oi->i_type = OMFS_FILE;
else {
printk(KERN_WARNING "omfs: unknown file type: %d\n",
inode->i_mode);
goto out_brelse;
}
oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
sizeof(struct omfs_header));
oi->i_head.h_version = 1;
oi->i_head.h_type = OMFS_INODE_NORMAL;
oi->i_head.h_magic = OMFS_IMAGIC;
oi->i_size = cpu_to_be64(inode->i_size);
ctime = inode_get_ctime_sec(inode) * 1000LL +
((inode_get_ctime_nsec(inode) + 999)/1000);
oi->i_ctime = cpu_to_be64(ctime);
omfs_update_checksums(oi);
mark_buffer_dirty(bh);
if (wait) {
sync_dirty_buffer(bh);
if (buffer_req(bh) && !buffer_uptodate(bh))
sync_failed = 1;
}
for (i = 1; i < sbi->s_mirrors; i++) {
bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
if (!bh2)
goto out_brelse;
memcpy(bh2->b_data, bh->b_data, bh->b_size);
mark_buffer_dirty(bh2);
if (wait) {
sync_dirty_buffer(bh2);
if (buffer_req(bh2) && !buffer_uptodate(bh2))
sync_failed = 1;
}
brelse(bh2);
}
ret = (sync_failed) ? -EIO : 0;
out_brelse:
brelse(bh);
out:
return ret;
}
static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
}
int omfs_sync_inode(struct inode *inode)
{
return __omfs_write_inode(inode, 1);
}
static void omfs_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
if (inode->i_nlink)
return;
if (S_ISREG(inode->i_mode)) {
inode->i_size = 0;
omfs_shrink_inode(inode);
}
omfs_clear_range(inode->i_sb, inode->i_ino, 2);
}
struct inode *omfs_iget(struct super_block *sb, ino_t ino)
{
struct omfs_sb_info *sbi = OMFS_SB(sb);
struct omfs_inode *oi;
struct buffer_head *bh;
u64 ctime;
unsigned long nsecs;
struct inode *inode;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode_state_read_once(inode) & I_NEW))
return inode;
bh = omfs_bread(inode->i_sb, ino);
if (!bh)
goto iget_failed;
oi = (struct omfs_inode *)bh->b_data;
if (ino != be64_to_cpu(oi->i_head.h_self))
goto fail_bh;
inode->i_uid = sbi->s_uid;
inode->i_gid = sbi->s_gid;
ctime = be64_to_cpu(oi->i_ctime);
nsecs = do_div(ctime, 1000) * 1000L;
inode_set_atime(inode, ctime, nsecs);
inode_set_mtime(inode, ctime, nsecs);
inode_set_ctime(inode, ctime, nsecs);
inode->i_mapping->a_ops = &omfs_aops;
switch (oi->i_type) {
case OMFS_DIR:
inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
inode->i_op = &omfs_dir_inops;
inode->i_fop = &omfs_dir_operations;
inode->i_size = sbi->s_sys_blocksize;
inc_nlink(inode);
break;
case OMFS_FILE:
inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
inode->i_fop = &omfs_file_operations;
inode->i_size = be64_to_cpu(oi->i_size);
break;
}
brelse(bh);
unlock_new_inode(inode);
return inode;
fail_bh:
brelse(bh);
iget_failed:
iget_failed(inode);
return ERR_PTR(-EIO);
}
static void omfs_put_super(struct super_block *sb)
{
struct omfs_sb_info *sbi = OMFS_SB(sb);
kfree(sbi->s_imap);
kfree(sbi);
sb->s_fs_info = NULL;
}
static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *s = dentry->d_sb;
struct omfs_sb_info *sbi = OMFS_SB(s);
u64 id = huge_encode_dev(s->s_bdev->bd_dev);
buf->f_type = OMFS_MAGIC;
buf->f_bsize = sbi->s_blocksize;
buf->f_blocks = sbi->s_num_blocks;
buf->f_files = sbi->s_num_blocks;
buf->f_namelen = OMFS_NAMELEN;
buf->f_fsid = u64_to_fsid(id);
buf->f_bfree = buf->f_bavail = buf->f_ffree =
omfs_count_free(s);
return 0;
}
static int omfs_show_options(struct seq_file *m, struct dentry *root)
{
struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
umode_t cur_umask = current_umask();
if (!uid_eq(sbi->s_uid, current_uid()))
seq_printf(m, ",uid=%u",
from_kuid_munged(&init_user_ns, sbi->s_uid));
if (!gid_eq(sbi->s_gid, current_gid()))
seq_printf(m, ",gid=%u",
from_kgid_munged(&init_user_ns, sbi->s_gid));
if (sbi->s_dmask == sbi->s_fmask) {
if (sbi->s_fmask != cur_umask)
seq_printf(m, ",umask=%o", sbi->s_fmask);
} else {
if (sbi->s_dmask != cur_umask)
seq_printf(m, ",dmask=%o", sbi->s_dmask);
if (sbi->s_fmask != cur_umask)
seq_printf(m, ",fmask=%o", sbi->s_fmask);
}
return 0;
}
static const struct super_operations omfs_sops = {
.write_inode = omfs_write_inode,
.evict_inode = omfs_evict_inode,
.put_super = omfs_put_super,
.statfs = omfs_statfs,
.show_options = omfs_show_options,
};
static int omfs_get_imap(struct super_block *sb)
{
unsigned int bitmap_size, array_size;
int count;
struct omfs_sb_info *sbi = OMFS_SB(sb);
struct buffer_head *bh;
unsigned long **ptr;
sector_t block;
bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
if (sbi->s_bitmap_ino == ~0ULL)
goto out;
sbi->s_imap_size = array_size;
sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL);
if (!sbi->s_imap)
goto nomem;
block = clus_to_blk(sbi, sbi->s_bitmap_ino);
if (block >= sbi->s_num_blocks)
goto nomem;
ptr = sbi->s_imap;
for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
bh = sb_bread(sb, block++);
if (!bh)
goto nomem_free;
*ptr = kmemdup(bh->b_data, sb->s_blocksize, GFP_KERNEL);
if (!*ptr) {
brelse(bh);
goto nomem_free;
}
if (count < sb->s_blocksize)
memset((void *)*ptr + count, 0xff,
sb->s_blocksize - count);
brelse(bh);
ptr++;
}
out:
return 0;
nomem_free:
for (count = 0; count < array_size; count++)
kfree(sbi->s_imap[count]);
kfree(sbi->s_imap);
nomem:
sbi->s_imap = NULL;
sbi->s_imap_size = 0;
return -ENOMEM;
}
struct omfs_mount_options {
kuid_t s_uid;
kgid_t s_gid;
int s_dmask;
int s_fmask;
};
enum {
Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask,
};
static const struct fs_parameter_spec omfs_param_spec[] = {
fsparam_uid ("uid", Opt_uid),
fsparam_gid ("gid", Opt_gid),
fsparam_u32oct ("umask", Opt_umask),
fsparam_u32oct ("dmask", Opt_dmask),
fsparam_u32oct ("fmask", Opt_fmask),
{}
};
static int
omfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct omfs_mount_options *opts = fc->fs_private;
int token;
struct fs_parse_result result;
if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
return 0;
token = fs_parse(fc, omfs_param_spec, param, &result);
if (token < 0)
return token;
switch (token) {
case Opt_uid:
opts->s_uid = result.uid;
break;
case Opt_gid:
opts->s_gid = result.gid;
break;
case Opt_umask:
opts->s_fmask = opts->s_dmask = result.uint_32;
break;
case Opt_dmask:
opts->s_dmask = result.uint_32;
break;
case Opt_fmask:
opts->s_fmask = result.uint_32;
break;
default:
return -EINVAL;
}
return 0;
}
static void
omfs_set_options(struct omfs_sb_info *sbi, struct omfs_mount_options *opts)
{
sbi->s_uid = opts->s_uid;
sbi->s_gid = opts->s_gid;
sbi->s_dmask = opts->s_dmask;
sbi->s_fmask = opts->s_fmask;
}
static int omfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct buffer_head *bh, *bh2;
struct omfs_super_block *omfs_sb;
struct omfs_root_block *omfs_rb;
struct omfs_sb_info *sbi;
struct inode *root;
struct omfs_mount_options *parsed_opts = fc->fs_private;
int ret = -EINVAL;
int silent = fc->sb_flags & SB_SILENT;
sbi = kzalloc_obj(struct omfs_sb_info);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
omfs_set_options(sbi, parsed_opts);
sb->s_maxbytes = 0xffffffff;
sb->s_time_gran = NSEC_PER_MSEC;
sb->s_time_min = 0;
sb->s_time_max = U64_MAX / MSEC_PER_SEC;
sb_set_blocksize(sb, 0x200);
bh = sb_bread(sb, 0);
if (!bh)
goto end;
omfs_sb = (struct omfs_super_block *)bh->b_data;
if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
if (!silent)
printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
omfs_sb->s_magic);
goto out_brelse_bh;
}
sb->s_magic = OMFS_MAGIC;
sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
mutex_init(&sbi->s_bitmap_lock);
if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) {
printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n",
(unsigned long long)sbi->s_num_blocks);
goto out_brelse_bh;
}
if (sbi->s_sys_blocksize > PAGE_SIZE) {
printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
sbi->s_sys_blocksize);
goto out_brelse_bh;
}
if (sbi->s_blocksize < sbi->s_sys_blocksize ||
sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
printk(KERN_ERR "omfs: block size (%d) is out of range\n",
sbi->s_blocksize);
goto out_brelse_bh;
}
sb_set_blocksize(sb, sbi->s_sys_blocksize);
sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
get_bitmask_order(sbi->s_sys_blocksize);
bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
if (!bh2)
goto out_brelse_bh;
omfs_rb = (struct omfs_root_block *)bh2->b_data;
sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
printk(KERN_ERR "omfs: block count discrepancy between "
"super and root blocks (%llx, %llx)\n",
(unsigned long long)sbi->s_num_blocks,
(unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
goto out_brelse_bh2;
}
if (sbi->s_bitmap_ino != ~0ULL &&
sbi->s_bitmap_ino > sbi->s_num_blocks) {
printk(KERN_ERR "omfs: free space bitmap location is corrupt "
"(%llx, total blocks %llx)\n",
(unsigned long long) sbi->s_bitmap_ino,
(unsigned long long) sbi->s_num_blocks);
goto out_brelse_bh2;
}
if (sbi->s_clustersize < 1 ||
sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
printk(KERN_ERR "omfs: cluster size out of range (%d)",
sbi->s_clustersize);
goto out_brelse_bh2;
}
ret = omfs_get_imap(sb);
if (ret)
goto out_brelse_bh2;
sb->s_op = &omfs_sops;
root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto out_brelse_bh2;
}
sb->s_root = d_make_root(root);
if (!sb->s_root) {
ret = -ENOMEM;
goto out_brelse_bh2;
}
printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
ret = 0;
out_brelse_bh2:
brelse(bh2);
out_brelse_bh:
brelse(bh);
end:
if (ret)
kfree(sbi);
return ret;
}
static int omfs_get_tree(struct fs_context *fc)
{
return get_tree_bdev(fc, omfs_fill_super);
}
static void omfs_free_fc(struct fs_context *fc);
static const struct fs_context_operations omfs_context_ops = {
.parse_param = omfs_parse_param,
.get_tree = omfs_get_tree,
.free = omfs_free_fc,
};
static int omfs_init_fs_context(struct fs_context *fc)
{
struct omfs_mount_options *opts;
opts = kzalloc_obj(*opts);
if (!opts)
return -ENOMEM;
opts->s_uid = current_uid();
opts->s_gid = current_gid();
opts->s_dmask = opts->s_fmask = current_umask();
fc->fs_private = opts;
fc->ops = &omfs_context_ops;
return 0;
}
static void omfs_free_fc(struct fs_context *fc)
{
kfree(fc->fs_private);
}
static struct file_system_type omfs_fs_type = {
.owner = THIS_MODULE,
.name = "omfs",
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
.init_fs_context = omfs_init_fs_context,
.parameters = omfs_param_spec,
};
MODULE_ALIAS_FS("omfs");
static int __init init_omfs_fs(void)
{
return register_filesystem(&omfs_fs_type);
}
static void __exit exit_omfs_fs(void)
{
unregister_filesystem(&omfs_fs_type);
}
module_init(init_omfs_fs);
module_exit(exit_omfs_fs);
