static int amfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
dev_t dev)
{
int err;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
amfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = vfs_mknod(lower_parent_dentry->d_inode, lower_dentry, mode, dev);
if (err)
goto out;
err = amfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, amfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
unlock_dir(lower_parent_dentry);
amfs_put_lower_path(dentry, &lower_path);
return err;
}
static int amfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
int err;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
amfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, mode);
if (err)
goto out;
err = amfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, amfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/* update number of links on parent directory */
set_nlink(dir, amfs_lower_inode(dir)->i_nlink);
out:
unlock_dir(lower_parent_dentry);
amfs_put_lower_path(dentry, &lower_path);
return err;
}
static int amfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
int err;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
/* char* value = NULL;
value = kzalloc(5,__GFP_WAIT);
if(value==NULL){
err = -ENOMEM;
goto out_err;
}
if(amfs_getxattr(dentry, AMFS_XATTR_NAME , value,5) > 0){
if(!strncmp(value,AMFS_BADFILE,3)){
err = -EPERM;
goto freevalue;
}
}else if(amfs_getxattr(dentry, AMFS_XATTR_NAME, value, 5)
!= -ENODATA){
err = amfs_getxattr(dentry, AMFS_XATTR_NAME, value, 5);
goto freevalue;
}
*/
amfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = vfs_symlink(lower_parent_dentry->d_inode, lower_dentry, symname);
if (err)
goto out;
err = amfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, amfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
unlock_dir(lower_parent_dentry);
amfs_put_lower_path(dentry, &lower_path);
return err;
}
static int amfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
{
struct dentry *lower_old_dentry;
struct dentry *lower_new_dentry;
struct dentry *lower_dir_dentry;
u64 file_size_save;
int err;
struct path lower_old_path, lower_new_path;
char *value = NULL;
if (old_dentry->d_inode->i_ino ==
AMFS_SB(old_dentry->d_sb)->inode_no) {
err = -EPERM;
goto out_err;
}
/************XATTR************/
value = kzalloc(5, __GFP_WAIT);
if (value == NULL) {
err = -ENOMEM;
goto out_err;
}
if (amfs_getxattr(old_dentry, AMFS_XATTR_NAME, value, 5) > 0) {
if (!strncmp(value, AMFS_BADFILE, 3)) {
err = -EPERM;
goto freevalue;
}
} else if (amfs_getxattr(old_dentry, AMFS_XATTR_NAME, value, 5)
!= -ENODATA){
err = amfs_getxattr(old_dentry, AMFS_XATTR_NAME, value, 5);
goto freevalue;
}
/************XATTR***********/
file_size_save = i_size_read(old_dentry->d_inode);
amfs_get_lower_path(old_dentry, &lower_old_path);
amfs_get_lower_path(new_dentry, &lower_new_path);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
lower_dir_dentry = lock_parent(lower_new_dentry);
err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
lower_new_dentry, NULL);
if (err || !lower_new_dentry->d_inode)
goto out;
err = amfs_interpose(new_dentry, dir->i_sb, &lower_new_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
set_nlink(old_dentry->d_inode,
amfs_lower_inode(old_dentry->d_inode)->i_nlink);
i_size_write(new_dentry->d_inode, file_size_save);
out:
unlock_dir(lower_dir_dentry);
amfs_put_lower_path(old_dentry, &lower_old_path);
amfs_put_lower_path(new_dentry, &lower_new_path);
freevalue:
kfree(value);
out_err:
return err;
}
/*
* Main driver function for amfs's lookup.
*
* Returns: NULL (ok), ERR_PTR if an error occurred.
* Fills in lower_parent_path with <dentry,mnt> on success.
*/
static struct dentry *__amfs_lookup(struct dentry *dentry,
unsigned int flags,
struct path *lower_parent_path)
{
int err = 0;
struct vfsmount *lower_dir_mnt;
struct dentry *lower_dir_dentry = NULL;
struct dentry *lower_dentry;
const char *name;
struct path lower_path;
struct qstr this;
/* must initialize dentry operations */
d_set_d_op(dentry, &amfs_dops);
if (IS_ROOT(dentry))
goto out;
name = dentry->d_name.name;
/* now start the actual lookup procedure */
lower_dir_dentry = lower_parent_path->dentry;
lower_dir_mnt = lower_parent_path->mnt;
// printk("\n lookup.c-> struct dentry * _amfs_lookup"); //aditi
/* Use vfs_path_lookup to check if the dentry exists or not */
err = vfs_path_lookup(lower_dir_dentry, lower_dir_mnt, name, 0,
&lower_path);
/* no error: handle positive dentries */
if (!err) {
amfs_set_lower_path(dentry, &lower_path);
err = amfs_interpose(dentry, dentry->d_sb, &lower_path);
if (err) /* path_put underlying path on error */
amfs_put_reset_lower_path(dentry);
goto out;
}
/*
* We don't consider ENOENT an error, and we want to return a
* negative dentry.
*/
if (err && err != -ENOENT)
goto out;
/* instatiate a new negative dentry */
this.name = name;
this.len = strlen(name);
this.hash = full_name_hash(this.name, this.len);
lower_dentry = d_lookup(lower_dir_dentry, &this);
if (lower_dentry)
goto setup_lower;
lower_dentry = d_alloc(lower_dir_dentry, &this);
if (!lower_dentry) {
err = -ENOMEM;
goto out;
}
d_add(lower_dentry, NULL); /* instantiate and hash */
setup_lower:
lower_path.dentry = lower_dentry;
lower_path.mnt = mntget(lower_dir_mnt);
amfs_set_lower_path(dentry, &lower_path);
/*
* If the intent is to create a file, then don't return an error, so
* the VFS will continue the process of making this negative dentry
* into a positive one.
*/
if (flags & (LOOKUP_CREATE|LOOKUP_RENAME_TARGET))
err = 0;
out:
return ERR_PTR(err);
}