/* allocate new dentry private data */
int new_dentry_private_data(struct dentry *dentry)
{
struct wrapfs_dentry_info *info = WRAPFS_D(dentry);
/* use zalloc to init dentry_info.lower_path */
info = kmem_cache_zalloc(wrapfs_dentry_cachep, GFP_ATOMIC);
if (!info)
return -ENOMEM;
spin_lock_init(&info->lock);
dentry->d_fsdata = info;
return 0;
}
static void wrapfs_d_release(struct dentry *dentry)
{
if (!dentry)
goto out;
if (unlikely(!WRAPFS_D(dentry)))
goto out;
UDBG;
/* wrapfs_lock_dentry(dentry, WRAPFS_DMUTEX_CHILD);
path_put_lowers_all(dentry, true); */
UDBG;
/* release and reset the lower paths */
/* wrapfs_put_reset_lower_path(dentry);
wrpafs_unlock_dentry(dentry);
*/
out:
free_dentry_private_data(dentry);
return;
}
/*
* There is no need to lock the wrapfs_super_info's rwsem as there is no
* way anyone can have a reference to the superblock at this point in time.
*/
static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
{
int err = 0, i = 0;
struct wrapfs_dentry_info *lower_root_info = NULL;
struct inode *inode = NULL;
if (!raw_data) {
printk(KERN_ERR
"u2fs: read_super: missing data argument\n");
err = -EINVAL;
goto out;
}
/* allocate superblock private data */
sb->s_fs_info = kzalloc(sizeof(struct wrapfs_sb_info), GFP_KERNEL);
if (!WRAPFS_SB(sb)) {
printk(KERN_CRIT "u2fs: read_super: out of memory\n");
err = -ENOMEM;
goto out_free;
}
atomic_set(&WRAPFS_SB(sb)->generation, 1);
WRAPFS_SB(sb)->high_branch_id = -1;
/* Parsing the Inputs */
lower_root_info = wrapfs_parse_options(sb, raw_data);
if (IS_ERR(lower_root_info)) {
printk(KERN_ERR
"u2fs: read_super: error while parsing options"
"(err = %ld)\n", PTR_ERR(lower_root_info));
err = PTR_ERR(lower_root_info);
lower_root_info = NULL;
goto out_free;
}
/* set the lower superblock field of upper superblock */
for (i = 0; i <= 1; i++) {
struct dentry *d = lower_root_info->lower_paths[i].dentry;
atomic_inc(&d->d_sb->s_active);
wrapfs_set_lower_super_idx(sb, i, d->d_sb);
}
/* inherit maxbytes from highest priority branch */
sb->s_maxbytes = wrapfs_lower_super_idx(sb, 0)->s_maxbytes;
/*
* Our c/m/atime granularity is 1 ns because we may stack on file
* systems whose granularity is as good.
*/
sb->s_time_gran = 1;
sb->s_op = &wrapfs_sops;
/* get a new inode and allocate our root dentry */
inode = wrapfs_new_iget(sb, iunique(sb, 1));
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_sput;
}
sb->s_root = d_alloc_root(inode);
if (unlikely(!sb->s_root)) {
err = -ENOMEM;
goto out_iput;
}
d_set_d_op(sb->s_root, &wrapfs_dops);
/* link the upper and lower dentries */
sb->s_root->d_fsdata = NULL;
err = new_dentry_private_data(sb->s_root);
if (unlikely(err))
goto out_freeroot;
/* if get here: cannot have error */
/* set the lower dentries for s_root */
for (i = 0; i <= 1 ; i++) {
struct dentry *d;
struct vfsmount *m;
d = lower_root_info->lower_paths[i].dentry;
m = lower_root_info->lower_paths[i].mnt;
wrapfs_set_lower_dentry_idx(sb->s_root, i, d);
wrapfs_set_lower_mnt_idx(sb->s_root, i, m);
}
atomic_set(&WRAPFS_D(sb->s_root)->generation, 1);
if (atomic_read(&inode->i_count) <= 1)
wrapfs_fill_inode(sb->s_root, inode);
/*
* No need to call interpose because we already have a positive
* dentry, which was instantiated by d_alloc_root. Just need to
* d_rehash it.
*/
d_rehash(sb->s_root);
if (!silent)
printk(KERN_INFO
"u2fs: mounted on top of type\n");
goto out;
/* all is well */
/* no longer needed: free_dentry_private_data(sb->s_root); */
out_freeroot:
if (WRAPFS_D(sb->s_root)) {
kfree(WRAPFS_D(sb->s_root)->lower_paths);
free_dentry_private_data(sb->s_root);
}
dput(sb->s_root);
out_iput:
iput(inode);
out_sput:
/* drop refs we took earlier */
if (lower_root_info && !IS_ERR(lower_root_info)) {
for (i = 0; i <= 1; i++) {
struct dentry *d;
d = lower_root_info->lower_paths[i].dentry;
atomic_dec(&d->d_sb->s_active);
path_put(&lower_root_info->lower_paths[i]);
}
kfree(lower_root_info->lower_paths);
kfree(lower_root_info);
lower_root_info = NULL;
}
out_free:
kfree(WRAPFS_SB(sb)->data);
kfree(WRAPFS_SB(sb));
sb->s_fs_info = NULL;
out:
if (lower_root_info && !IS_ERR(lower_root_info)) {
kfree(lower_root_info->lower_paths);
kfree(lower_root_info);
}
return err;
}
