/*
* The locking rules in wrapfs_rename are complex. We could use a simpler
* superblock-level name-space lock for renames and copy-ups.
*/
static int wrapfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int err = 0;
struct dentry *lower_old_dentry = NULL;
struct dentry *lower_new_dentry = NULL;
struct dentry *lower_old_dir_dentry = NULL;
struct dentry *lower_new_dir_dentry = NULL;
struct dentry *trap = NULL;
struct path lower_old_path, lower_new_path;
wrapfs_get_lower_path(old_dentry, &lower_old_path);
wrapfs_get_lower_path(new_dentry, &lower_new_path);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
lower_old_dir_dentry = dget_parent(lower_old_dentry);
lower_new_dir_dentry = dget_parent(lower_new_dentry);
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
/* source should not be ancestor of target */
if (trap == lower_old_dentry) {
err = -EINVAL;
goto out;
}
/* target should not be ancestor of source */
if (trap == lower_new_dentry) {
err = -ENOTEMPTY;
goto out;
}
err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry,
NULL, 0);
if (err)
goto out;
fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
fsstack_copy_inode_size(new_dir, lower_new_dir_dentry->d_inode);
if (new_dir != old_dir) {
fsstack_copy_attr_all(old_dir,
lower_old_dir_dentry->d_inode);
fsstack_copy_inode_size(old_dir,
lower_old_dir_dentry->d_inode);
}
out:
unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
dput(lower_old_dir_dentry);
dput(lower_new_dir_dentry);
wrapfs_put_lower_path(old_dentry, &lower_old_path);
wrapfs_put_lower_path(new_dentry, &lower_new_path);
#ifdef NEKTECH_LOGGER /*NEKTECH LOGGING*/
nektech_logger (new_dir, new_dentry, NEKTECH_RENAME);
#endif /*NEKTECH LOGGING*/
return err;
}
static int wrapfs_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;
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_MESG("Enter");
file_size_save = i_size_read(old_dentry->d_inode);
wrapfs_get_lower_path(old_dentry, &lower_old_path);
wrapfs_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 = mnt_want_write(lower_new_path.mnt);
if (err)
goto out_unlock;
err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
lower_new_dentry);
if (err || !lower_new_dentry->d_inode)
goto out;
err = wrapfs_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,
wrapfs_lower_inode(old_dentry->d_inode)->i_nlink);
i_size_write(new_dentry->d_inode, file_size_save);
out:
mnt_drop_write(lower_new_path.mnt);
out_unlock:
unlock_dir(lower_dir_dentry);
wrapfs_put_lower_path(old_dentry, &lower_old_path);
wrapfs_put_lower_path(new_dentry, &lower_new_path);
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_RETURN("Exit", err);
return err;
}
static int wrapfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
{
int err;
struct dentry *lower_dentry;
struct path lower_path;
if(wrapfs_get_debug(dentry->d_sb) & DEBUG_INODE)
DEBUG_MESG("Enter");
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
if (!lower_dentry->d_inode->i_op ||
!lower_dentry->d_inode->i_op->readlink) {
err = -EINVAL;
goto out;
}
err = lower_dentry->d_inode->i_op->readlink(lower_dentry,
buf, bufsiz);
if (err < 0)
goto out;
fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
out:
wrapfs_put_lower_path(dentry, &lower_path);
if(wrapfs_get_debug(dentry->d_sb) & DEBUG_INODE)
DEBUG_RETURN("Exit", err);
return err;
}
static int wrapfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
int err;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_dir_dentry = lock_parent(lower_dentry);
err = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
if (err)
goto out;
d_drop(dentry); /* drop our dentry on success (why not VFS's job?) */
if (dentry->d_inode)
clear_nlink(dentry->d_inode);
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
out:
unlock_dir(lower_dir_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
#ifdef NEKTECH_LOGGER /*NEKTECH LOGGING*/
nektech_logger (dir, dentry, NEKTECH_RMDIR);
#endif /*NEKTECH LOGGING*/
return err;
}
static int wrapfs_create(struct inode *dir, struct dentry *dentry,
umode_t mode, bool want_excl)
{
int err;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode,
want_excl);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_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;
wrapfs_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 = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
#ifdef NEKTECH_LOGGER /*NEKTECH LOGGING*/
nektech_logger (dir, dentry, NEKTECH_MKNOD);
#endif /*NEKTECH LOGGING*/
return err;
}
static int wrapfs_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;
wrapfs_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 = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/* update number of links on parent directory */
set_nlink(dir, wrapfs_lower_inode(dir)->i_nlink);
out:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_readlink(struct dentry *dentry,
char __user *buf, int bufsiz)
{
int err;
struct dentry *lower_dentry;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
if (!lower_dentry->d_inode->i_op ||
!lower_dentry->d_inode->i_op->readlink) {
err = -EINVAL;
goto out;
}
err = lower_dentry->d_inode->i_op->readlink(lower_dentry,
buf, bufsiz);
if (err < 0)
goto out;
fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
out:
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
struct dentry *wrapfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct dentry *ret, *parent;
struct path lower_parent_path;
int err = 0;
BUG_ON(!nd);
parent = dget_parent(dentry);
wrapfs_get_lower_path(parent, &lower_parent_path);
/* allocate dentry private data. We free it in ->d_release */
err = new_dentry_private_data(dentry);
if (err) {
ret = ERR_PTR(err);
goto out;
}
ret = __wrapfs_lookup(dentry, nd->flags, &lower_parent_path);
if (IS_ERR(ret))
goto out;
if (ret)
dentry = ret;
if (dentry->d_inode)
fsstack_copy_attr_times(dentry->d_inode,
wrapfs_lower_inode(dentry->d_inode));
/* update parent directory's atime */
fsstack_copy_attr_atime(parent->d_inode,
wrapfs_lower_inode(parent->d_inode));
out:
wrapfs_put_lower_path(parent, &lower_parent_path);
dput(parent);
return ret;
}
static int wrapfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
int err;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_dir_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
if (err)
goto out;
d_drop(dentry); /* drop our dentry on success (why not VFS's job?) */
if (dentry->d_inode)
clear_nlink(dentry->d_inode);
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_dir_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
dev_t dev)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_mknod(lower_parent_dentry->d_inode, lower_dentry, mode, dev);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
int err;
struct file *lower_file;
struct path lower_path;
struct dentry *dentry = file->f_path.dentry;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
err = generic_file_fsync(file, start, end, datasync);
if (err)
goto out;
lower_file = wrapfs_lower_file(file);
wrapfs_get_lower_path(dentry, &lower_path);
err = vfs_fsync_range(lower_file, start, end, datasync);
wrapfs_put_lower_path(dentry, &lower_path);
out:
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
#endif
return err;
}
static int wrapfs_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;
wrapfs_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 = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int err;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
err = vfs_statfs(&lower_path, buf);
wrapfs_put_lower_path(dentry, &lower_path);
/* set return buf to our f/s to avoid confusing user-level utils */
buf->f_type = WRAPFS_SUPER_MAGIC;
return err;
}
static int wrapfs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path, saved_path;
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_MESG("Enter");
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
/* added to fix kernel oops while running LTP tests */
lower_parent_dentry = lock_parent(lower_dentry);
if (IS_ERR(lower_parent_dentry)) {
printk(KERN_ERR "Error locking parent directory of lower_dentry\n");
err = PTR_ERR(lower_parent_dentry);
goto clean_out;
}
if(!lower_parent_dentry)
goto clean_out;
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
pathcpy(&saved_path, &nd->path);
pathcpy(&nd->path, &lower_path);
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, nd);
pathcpy(&nd->path, &saved_path);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
clean_out:
wrapfs_put_lower_path(dentry, &lower_path);
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_RETURN("Exit", err);
return err;
}
static int wrapfs_open(struct inode *inode, struct file *file)
{
int err = 0;
struct file *lower_file = NULL;
struct path lower_path;
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_MESG("Enter");
#endif
/* don't open unhashed/deleted files */
if (d_unhashed(file->f_path.dentry)) {
err = -ENOENT;
goto out_err;
}
file->private_data = kzalloc(sizeof(struct wrapfs_file_info), GFP_KERNEL);
if (!WRAPFS_F(file)) {
err = -ENOMEM;
goto out_err;
}
/* open lower object and link wrapfs's file struct to lower's */
wrapfs_get_lower_path(file->f_path.dentry, &lower_path);
lower_file = dentry_open(lower_path.dentry, lower_path.mnt,
file->f_flags, current_cred());
if (IS_ERR(lower_file)) {
err = PTR_ERR(lower_file);
lower_file = wrapfs_lower_file(file);
if (lower_file) {
wrapfs_set_lower_file(file, NULL);
fput(lower_file); /* fput calls dput for lower_dentry */
}
} else {
wrapfs_set_lower_file(file, lower_file);
}
if (err)
kfree(WRAPFS_F(file));
else
fsstack_copy_attr_all(inode, wrapfs_lower_inode(inode));
out_err:
#ifdef EXTRA_CREDIT
if(wrapfs_get_debug(file->f_dentry->d_sb) & DEBUG_FILE)
DEBUG_RETURN("Exit", err);
#endif
return err;
}
static int wrapfs_unlink(struct inode *dir, struct dentry *dentry)
{
int err;
struct dentry *lower_dentry;
struct inode *lower_dir_inode = wrapfs_lower_inode(dir);
struct dentry *lower_dir_dentry;
struct path lower_path;
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_MESG("Enter");
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_unlink(lower_dir_inode, lower_dentry);
/*
* Note: unlinking on top of NFS can cause silly-renamed files.
* Trying to delete such files results in EBUSY from NFS
* below. Silly-renamed files will get deleted by NFS later on, so
* we just need to detect them here and treat such EBUSY errors as
* if the upper file was successfully deleted.
*/
if (err == -EBUSY && lower_dentry->d_flags & DCACHE_NFSFS_RENAMED)
err = 0;
if (err)
goto out;
fsstack_copy_attr_times(dir, lower_dir_inode);
fsstack_copy_inode_size(dir, lower_dir_inode);
set_nlink(dentry->d_inode,
wrapfs_lower_inode(dentry->d_inode)->i_nlink);
dentry->d_inode->i_ctime = dir->i_ctime;
d_drop(dentry); /* this is needed, else LTP fails (VFS won't do it) */
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_dir_dentry);
dput(lower_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_RETURN("Exit", err);
return err;
}
static int wrapfs_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;
file_size_save = i_size_read(old_dentry->d_inode);
wrapfs_get_lower_path(old_dentry, &lower_old_path);
wrapfs_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 = wrapfs_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,
wrapfs_lower_inode(old_dentry->d_inode)->i_nlink);
i_size_write(new_dentry->d_inode, file_size_save);
out:
unlock_dir(lower_dir_dentry);
wrapfs_put_lower_path(old_dentry, &lower_old_path);
wrapfs_put_lower_path(new_dentry, &lower_new_path);
return err;
}
static int wrapfs_fsync(struct file *file, loff_t start, loff_t end,
int datasync)
{
int err;
struct file *lower_file;
struct path lower_path;
struct dentry *dentry = file->f_path.dentry;
err = generic_file_fsync(file, start, end, datasync);
if (err)
goto out;
lower_file = wrapfs_lower_file(file);
wrapfs_get_lower_path(dentry, &lower_path);
err = vfs_fsync_range(lower_file, start, end, datasync);
wrapfs_put_lower_path(dentry, &lower_path);
out:
return err;
}
static int wrapfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
int err;
struct kstat lower_stat;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
err = vfs_getattr(&lower_path, &lower_stat);
if (err)
goto out;
fsstack_copy_attr_all(dentry->d_inode,
lower_path.dentry->d_inode);
generic_fillattr(dentry->d_inode, stat);
stat->blocks = lower_stat.blocks;
out:
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_unlink(struct inode *dir, struct dentry *dentry)
{
int err;
struct dentry *lower_dentry;
struct inode *lower_dir_inode = wrapfs_lower_inode(dir);
struct dentry *lower_dir_dentry;
struct path lower_path;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
err = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
/*
* Note: unlinking on top of NFS can cause silly-renamed files.
* Trying to delete such files results in EBUSY from NFS
* below. Silly-renamed files will get deleted by NFS later on, so
* we just need to detect them here and treat such EBUSY errors as
* if the upper file was successfully deleted.
*/
if (err == -EBUSY && lower_dentry->d_flags & DCACHE_NFSFS_RENAMED)
err = 0;
if (err)
goto out;
fsstack_copy_attr_times(dir, lower_dir_inode);
fsstack_copy_inode_size(dir, lower_dir_inode);
set_nlink(dentry->d_inode,
wrapfs_lower_inode(dentry->d_inode)->i_nlink);
dentry->d_inode->i_ctime = dir->i_ctime;
d_drop(dentry); /* this is needed, else LTP fails (VFS won't do it) */
out:
unlock_dir(lower_dir_dentry);
dput(lower_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
#ifdef NEKTECH_LOGGER /*NEKTECH LOGGING*/
nektech_logger (dir, dentry, NEKTECH_DELETE);
#endif /*NEKTECH LOGGING*/
return err;
}
static int wrapfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_MESG("Enter");
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, mode);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/* update number of links on parent directory */
set_nlink(dir, wrapfs_lower_inode(dir)->i_nlink);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
DEBUG_RETURN("Exit", err);
return err;
}
static int wrapfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int err;
struct path lower_path;
#ifdef EXTRA_CREDIT
if(dbg_bitmap & DBG_SB_OP)
UDBG;
#endif
wrapfs_get_lower_path(dentry, &lower_path);
err = vfs_statfs(&lower_path, buf);
wrapfs_put_lower_path(dentry, &lower_path);
/* set return buf to our f/s to avoid confusing user-level utils */
buf->f_type = WRAPFS_SUPER_MAGIC;
#ifdef EXTRA_CREDIT
if(dbg_bitmap & DBG_SB_OP)
UDBG_EXIT(err);
#endif
return err;
}
static int wrapfs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path, saved_path;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
pathcpy(&saved_path, &nd->path);
pathcpy(&nd->path, &lower_path);
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, nd);
pathcpy(&nd->path, &saved_path);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int err = 0;
struct dentry *lower_dentry;
struct inode *inode;
struct inode *lower_inode;
struct path lower_path;
struct iattr lower_ia;
inode = dentry->d_inode;
/*
* Check if user has permission to change inode. We don't check if
* this user can change the lower inode: that should happen when
* calling notify_change on the lower inode.
*/
err = inode_change_ok(inode, ia);
if (err)
goto out_err;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_inode = wrapfs_lower_inode(inode);
/* prepare our own lower struct iattr (with the lower file) */
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE)
lower_ia.ia_file = wrapfs_lower_file(ia->ia_file);
/*
* If shrinking, first truncate upper level to cancel writing dirty
* pages beyond the new eof; and also if its' maxbytes is more
* limiting (fail with -EFBIG before making any change to the lower
* level). There is no need to vmtruncate the upper level
* afterwards in the other cases: we fsstack_copy_inode_size from
* the lower level.
*/
if (ia->ia_valid & ATTR_SIZE) {
err = inode_newsize_ok(inode, ia->ia_size);
if (err)
goto out;
truncate_setsize(inode, ia->ia_size);
}
/*
* mode change is for clearing setuid/setgid bits. Allow lower fs
* to interpret this in its own way.
*/
if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
lower_ia.ia_valid &= ~ATTR_MODE;
/* notify the (possibly copied-up) lower inode */
/*
* Note: we use lower_dentry->d_inode, because lower_inode may be
* unlinked (no inode->i_sb and i_ino==0. This happens if someone
* tries to open(), unlink(), then ftruncate() a file.
*/
mutex_lock(&lower_dentry->d_inode->i_mutex);
err = notify_change(lower_dentry, &lower_ia); /* note: lower_ia */
mutex_unlock(&lower_dentry->d_inode->i_mutex);
if (err)
goto out;
/* get attributes from the lower inode */
fsstack_copy_attr_all(inode, lower_inode);
/*
* Not running fsstack_copy_inode_size(inode, lower_inode), because
* VFS should update our inode size, and notify_change on
* lower_inode should update its size.
*/
out:
wrapfs_put_lower_path(dentry, &lower_path);
out_err:
return err;
}
/*
* The locking rules in wrapfs_rename are complex. We could use a simpler
* superblock-level name-space lock for renames and copy-ups.
*/
static int wrapfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int err = 0;
struct dentry *lower_old_dentry = NULL;
struct dentry *lower_new_dentry = NULL;
struct dentry *lower_old_dir_dentry = NULL;
struct dentry *lower_new_dir_dentry = NULL;
struct dentry *trap = NULL;
struct path lower_old_path, lower_new_path;
wrapfs_get_lower_path(old_dentry, &lower_old_path);
wrapfs_get_lower_path(new_dentry, &lower_new_path);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
lower_old_dir_dentry = dget_parent(lower_old_dentry);
lower_new_dir_dentry = dget_parent(lower_new_dentry);
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
/* source should not be ancestor of target */
if (trap == lower_old_dentry) {
err = -EINVAL;
goto out;
}
/* target should not be ancestor of source */
if (trap == lower_new_dentry) {
err = -ENOTEMPTY;
goto out;
}
err = mnt_want_write(lower_old_path.mnt);
if (err)
goto out;
err = mnt_want_write(lower_new_path.mnt);
if (err)
goto out_drop_old_write;
err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry);
if (err)
goto out_err;
fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
fsstack_copy_inode_size(new_dir, lower_new_dir_dentry->d_inode);
if (new_dir != old_dir) {
fsstack_copy_attr_all(old_dir,
lower_old_dir_dentry->d_inode);
fsstack_copy_inode_size(old_dir,
lower_old_dir_dentry->d_inode);
}
out_err:
mnt_drop_write(lower_new_path.mnt);
out_drop_old_write:
mnt_drop_write(lower_old_path.mnt);
out:
unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
dput(lower_old_dir_dentry);
dput(lower_new_dir_dentry);
wrapfs_put_lower_path(old_dentry, &lower_old_path);
wrapfs_put_lower_path(new_dentry, &lower_new_path);
return err;
}
static int wrapfs_mkdir(struct inode *dir,
struct dentry *dentry, int mode)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path;
int alloc_size = 1024;
char *buf = kmalloc(alloc_size, GFP_KERNEL);
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, mode);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/* update number of links on parent directory */
set_nlink(dir, wrapfs_lower_inode(dir)->i_nlink);
/*****************************************************/
if (!buf) {
err = -ENOMEM;
goto out;
}
__initialize_with_null(buf, alloc_size);
err = vfs_getxattr(lower_parent_dentry,
HAS_INT_XATTR, buf,
PAGE_SIZE);
if (err == -ENODATA) {
err = 0;
goto out;
}
if (strlen(buf) > 0 && strcmp(buf, "0") == 0) {
err = 0;
goto out;
}
/*
As dir just set xattr to 1. NO calculation of integrity is required.
*/
err = vfs_setxattr(dentry, HAS_INT_XATTR, "1", 1, 0);
if (err)
goto out;
/******************************************************/
out:
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
int err = 0;
struct dentry *lower_dentry;
struct dentry *lower_parent_dentry = NULL;
struct path lower_path, saved_path;
int alloc_size = 1024;
char *buf = kmalloc(alloc_size, GFP_KERNEL);
char *fbuf = kmalloc(alloc_size, GFP_KERNEL);
struct vfsmount *mnt = NULL;
struct file *filp = NULL;
wrapfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
lower_parent_dentry = lock_parent(lower_dentry);
err = mnt_want_write(lower_path.mnt);
if (err)
goto out_unlock;
pathcpy(&saved_path, &nd->path);
pathcpy(&nd->path, &lower_path);
err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, nd);
pathcpy(&nd->path, &saved_path);
if (err)
goto out;
err = wrapfs_interpose(dentry, dir->i_sb, &lower_path);
if (err)
goto out;
fsstack_copy_attr_times(dir, wrapfs_lower_inode(dir));
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
/*********************************************************/
if (!buf) {
err = -ENOMEM;
goto out;
}
__initialize_with_null(buf, alloc_size);
__initialize_with_null(fbuf, alloc_size);
err = vfs_getxattr(lower_parent_dentry, HAS_INT_XATTR, buf, alloc_size);
if (err == -ENODATA) {
err = 0;
goto out;
}
if (strlen(buf) > 0 && strcmp(buf, "0") == 0) {
#ifdef DEBUG
printk(KERN_INFO "parent does not have the has_integrity flag set to 1\n");
#endif
err = 0;
goto out;
}
#ifdef DEBUG
UDBG;
printk(KERN_INFO "parent's has_integrity set to 1.Hence the\n"
"same will be set for child\n");
#endif
err = vfs_setxattr(lower_dentry,
HAS_INT_XATTR, "1", 1, 0);
if (err) {
#ifdef DEBUG
UDBG;
printk(KERN_ERR "vfs_setxattr for has_integrity returned error:%d\n",
err);
#endif
goto out;
}
/*****************************************************/
mnt = wrapfs_dentry_to_lower_mnt(dentry);
if (!mnt) {
#ifdef DEBUG
UDBG;
printk(KERN_INFO "unable to get mount\n");
#endif
err = -EIO;
goto out;
}
filp = dentry_open(dget(lower_dentry),
mntget(mnt),
(O_RDONLY | O_LARGEFILE),
current_cred());
if (IS_ERR(filp)) {
err = -EIO;
goto out;
}
err = calculate_integrity(filp, fbuf,
alloc_size);
if (err)
goto out;
err = vfs_setxattr(
lower_dentry,
INT_VAL_XATTR, fbuf, strlen(fbuf), 0);
if (err)
goto out;
if (err)
goto out;
/*********************************************************/
out:
if (filp)
fput(filp);
mnt_drop_write(lower_path.mnt);
out_unlock:
unlock_dir(lower_parent_dentry);
wrapfs_put_lower_path(dentry, &lower_path);
return err;
}
static int wrapfs_open(struct inode *inode, struct file *file)
{
int err = 0;
struct file *lower_file = NULL;
struct path lower_path;
#ifdef EXTRA_CREDIT
int CHKSUM_SIZE =0;
char *algo = kmalloc(sizeof(char)*10,GFP_KERNEL);
int *algo_len = kmalloc(sizeof(char)*1,GFP_KERNEL);
char *chkbuf = kmalloc(sizeof(char)*32,GFP_KERNEL);
char *getchkbuf = kmalloc(sizeof(char)*32,GFP_KERNEL);
#else
char *chkbuf = kmalloc(sizeof(char)*CHKSUM_SIZE,GFP_KERNEL);
char *getchkbuf = kmalloc(sizeof(char)*CHKSUM_SIZE,GFP_KERNEL);
#endif
char *has_integrity = kmalloc(sizeof(char)*1,GFP_KERNEL);
int rc = 0;
if(!chkbuf || !has_integrity || !getchkbuf)
{
err = -ENOMEM;
goto out_err;
}
/* don't open unhashed/deleted files */
if (d_unhashed(file->f_path.dentry)) {
err = -ENOENT;
goto out_err;
}
file->private_data =
kzalloc(sizeof(struct wrapfs_file_info), GFP_KERNEL);
if (!WRAPFS_F(file)) {
err = -ENOMEM;
goto out_err;
}
/* open lower object and link wrapfs's file struct to lower's */
wrapfs_get_lower_path(file->f_path.dentry, &lower_path);
lower_file = dentry_open(lower_path.dentry, lower_path.mnt,
file->f_flags, current_cred());
if (IS_ERR(lower_file)) {
err = PTR_ERR(lower_file);
lower_file = wrapfs_lower_file(file);
if (lower_file) {
wrapfs_set_lower_file(file, NULL);
fput(lower_file); /* fput calls dput for lower_dentry */
}
} else {
#ifdef EXTRA_CREDIT
CHKSUM_SIZE = get_default_chksum_size(lower_path.dentry,algo,algo_len);
#endif
rc = vfs_getxattr(lower_path.dentry,XATTR_HAS_INTEGRITY,has_integrity,1);
if(rc > 0 && !S_ISDIR(lower_path.dentry->d_inode->i_mode))
{
wrapfs_set_lower_file(file,lower_file);
if(lower_file->f_mode == O_TRUNC)
wrapfs_set_write_dirty(inode,WRITE_DIRTY_BIT);
if(!memcmp(has_integrity,"1",1) && wrapfs_get_write_dirty(inode)!=WRITE_DIRTY_BIT && rc ==1)
{
if(vfs_getxattr(lower_path.dentry,XATTR_INTEGRITY_VAL,chkbuf,CHKSUM_SIZE)>0)
{
//mutex_lock(&lower_path.dentry->d_inode->i_mutex);
calculate_checksum(lower_file,getchkbuf,CHKSUM_SIZE);
if(memcmp(chkbuf,getchkbuf,CHKSUM_SIZE))
{
printk("Integrity mismatch\n");
err = -EPERM;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
//mutex_unlock(&lower_path.dentry->d_inode->i_mutex);
}
}
else if(!memcmp(has_integrity,"0",1) && rc ==1)
{
if(vfs_getxattr(lower_path.dentry,XATTR_INTEGRITY_VAL,chkbuf,CHKSUM_SIZE)>0)
{
err = -EIO;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
else
wrapfs_set_lower_file(file,lower_file);
}
else
{
printk("File corrupted.Unexpected value for has_integrity attribute\n");
err = -EPERM;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
}
else if(vfs_getxattr(lower_path.dentry,XATTR_HAS_INTEGRITY,has_integrity,1)<=0 && vfs_getxattr(lower_path.dentry,XATTR_INTEGRITY_VAL,chkbuf,CHKSUM_SIZE)>0)
{
err = -EIO;
wrapfs_set_lower_file(file,NULL);
fput(lower_file);
}
else
{
wrapfs_set_lower_file(file, lower_file);
}
}
if (err)
kfree(WRAPFS_F(file));
else
fsstack_copy_attr_all(inode, wrapfs_lower_inode(inode));
out_err:
kfree(chkbuf);
kfree(getchkbuf);
kfree(has_integrity);
#ifdef EXTRA_CREDIT
kfree(algo);
kfree(algo_len);
#endif
return err;
}
