static int ovl_dentry_open(struct dentry *dentry, struct file *file,
const struct cred *cred)
{
int err;
struct path realpath;
enum ovl_path_type type;
bool want_write = false;
type = ovl_path_real(dentry, &realpath);
if (ovl_open_need_copy_up(file->f_flags, type, realpath.dentry)) {
want_write = true;
err = ovl_want_write(dentry);
if (err)
goto out;
if (file->f_flags & O_TRUNC)
err = ovl_copy_up_last(dentry, NULL, true);
else
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
ovl_path_upper(dentry, &realpath);
}
err = vfs_open(&realpath, file, cred);
out_drop_write:
if (want_write)
ovl_drop_write(dentry);
out:
return err;
}
int ovl_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
int err;
struct dentry *upperdentry;
err = ovl_want_write(dentry);
if (err)
goto out;
err = -EPERM;
if (ovl_is_private_xattr(name))
goto out_drop_write;
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
upperdentry = ovl_dentry_upper(dentry);
err = vfs_setxattr(upperdentry, name, value, size, flags);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
int ovl_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct path realpath;
enum ovl_path_type type;
err = ovl_want_write(dentry);
if (err)
goto out;
if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
ovl_is_private_xattr(name))
goto out_drop_write;
type = ovl_path_real(dentry, &realpath);
if (type == OVL_PATH_LOWER) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
ovl_path_upper(dentry, &realpath);
}
err = vfs_removexattr(realpath.dentry, name);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
const char *link)
{
int err;
struct inode *inode;
struct kstat stat = {
.rdev = rdev,
};
err = ovl_want_write(dentry);
if (err)
goto out;
err = -ENOMEM;
inode = ovl_new_inode(dentry->d_sb, mode);
if (!inode)
goto out_drop_write;
inode_init_owner(inode, dentry->d_parent->d_inode, mode);
stat.mode = inode->i_mode;
err = ovl_create_or_link(dentry, inode, &stat, link, NULL);
if (err)
iput(inode);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
const char *link)
{
int err;
struct inode *inode;
struct ovl_cattr attr = {
.rdev = rdev,
.link = link,
};
err = ovl_want_write(dentry);
if (err)
goto out;
/* Preallocate inode to be used by ovl_get_inode() */
err = -ENOMEM;
inode = ovl_new_inode(dentry->d_sb, mode, rdev);
if (!inode)
goto out_drop_write;
inode_init_owner(inode, dentry->d_parent->d_inode, mode);
attr.mode = inode->i_mode;
err = ovl_create_or_link(dentry, inode, &attr, false);
/* Did we end up using the preallocated inode? */
if (inode != d_inode(dentry))
iput(inode);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
int ovl_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct path realpath;
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
err = ovl_want_write(dentry);
if (err)
goto out;
err = -ENODATA;
if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
goto out_drop_write;
if (!OVL_TYPE_UPPER(type)) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
ovl_path_upper(dentry, &realpath);
}
err = vfs_removexattr(realpath.dentry, name);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags)
{
int err;
struct path realpath;
enum ovl_path_type type;
type = ovl_path_real(dentry, &realpath);
if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
err = ovl_want_write(dentry);
if (err)
return ERR_PTR(err);
if (file_flags & O_TRUNC)
err = ovl_copy_up_last(dentry, NULL, true);
else
err = ovl_copy_up(dentry);
ovl_drop_write(dentry);
if (err)
return ERR_PTR(err);
ovl_path_upper(dentry, &realpath);
}
return d_backing_inode(realpath.dentry);
}
struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags)
{
int err;
struct path realpath;
enum ovl_path_type type;
if (d_is_dir(dentry))
return d_backing_inode(dentry);
type = ovl_path_real(dentry, &realpath);
if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
err = ovl_want_write(dentry);
if (err)
return ERR_PTR(err);
if (file_flags & O_TRUNC)
err = ovl_copy_up_truncate(dentry);
else
err = ovl_copy_up(dentry);
ovl_drop_write(dentry);
if (err)
return ERR_PTR(err);
ovl_path_upper(dentry, &realpath);
}
if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE)
return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags);
return d_backing_inode(realpath.dentry);
}
int ovl_setattr(struct dentry *dentry, struct iattr *attr)
{
int err;
struct dentry *upperdentry;
/*
* Check for permissions before trying to copy-up. This is redundant
* since it will be rechecked later by ->setattr() on upper dentry. But
* without this, copy-up can be triggered by just about anybody.
*
* We don't initialize inode->size, which just means that
* inode_newsize_ok() will always check against MAX_LFS_FILESIZE and not
* check for a swapfile (which this won't be anyway).
*/
err = inode_change_ok(dentry->d_inode, attr);
if (err)
return err;
err = ovl_want_write(dentry);
if (err)
goto out;
if (attr->ia_valid & ATTR_SIZE) {
struct inode *realinode = d_inode(ovl_dentry_real(dentry));
err = -ETXTBSY;
if (atomic_read(&realinode->i_writecount) < 0)
goto out_drop_write;
}
err = ovl_copy_up(dentry);
if (!err) {
struct inode *winode = NULL;
upperdentry = ovl_dentry_upper(dentry);
if (attr->ia_valid & ATTR_SIZE) {
winode = d_inode(upperdentry);
err = get_write_access(winode);
if (err)
goto out_drop_write;
}
inode_lock(upperdentry->d_inode);
err = notify_change(upperdentry, attr, NULL);
if (!err)
ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
inode_unlock(upperdentry->d_inode);
if (winode)
put_write_access(winode);
}
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
const char *link)
{
int err;
err = ovl_want_write(dentry);
if (!err) {
err = ovl_create_or_link(dentry, mode, rdev, link, NULL);
ovl_drop_write(dentry);
}
return err;
}
int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
{
int err = 0;
if (ovl_open_need_copy_up(dentry, file_flags)) {
err = ovl_want_write(dentry);
if (!err) {
err = ovl_copy_up_flags(dentry, file_flags);
ovl_drop_write(dentry);
}
}
return err;
}
int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
{
int err = 0;
struct path realpath;
enum ovl_path_type type;
type = ovl_path_real(dentry, &realpath);
if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
err = ovl_want_write(dentry);
if (!err) {
err = ovl_copy_up_flags(dentry, file_flags);
ovl_drop_write(dentry);
}
}
return err;
}
int ovl_setattr(struct dentry *dentry, struct iattr *attr)
{
int err;
struct dentry *upperdentry;
const struct cred *old_cred;
/*
* Check for permissions before trying to copy-up. This is redundant
* since it will be rechecked later by ->setattr() on upper dentry. But
* without this, copy-up can be triggered by just about anybody.
*
* We don't initialize inode->size, which just means that
* inode_newsize_ok() will always check against MAX_LFS_FILESIZE and not
* check for a swapfile (which this won't be anyway).
*/
err = setattr_prepare(dentry, attr);
if (err)
return err;
err = ovl_want_write(dentry);
if (err)
goto out;
err = ovl_copy_up(dentry);
if (!err) {
upperdentry = ovl_dentry_upper(dentry);
if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
attr->ia_valid &= ~ATTR_MODE;
inode_lock(upperdentry->d_inode);
old_cred = ovl_override_creds(dentry->d_sb);
err = notify_change(upperdentry, attr, NULL);
revert_creds(old_cred);
if (!err)
ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
inode_unlock(upperdentry->d_inode);
}
ovl_drop_write(dentry);
out:
return err;
}
int ovl_setattr(struct dentry *dentry, struct iattr *attr)
{
int err;
struct dentry *upperdentry;
err = ovl_want_write(dentry);
if (err)
goto out;
upperdentry = ovl_dentry_upper(dentry);
if (upperdentry) {
mutex_lock(&upperdentry->d_inode->i_mutex);
err = notify_change(upperdentry, attr, NULL);
mutex_unlock(&upperdentry->d_inode->i_mutex);
} else {
err = ovl_copy_up_last(dentry, attr, false);
}
ovl_drop_write(dentry);
out:
return err;
}
int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
int err;
struct dentry *upperdentry = ovl_i_dentry_upper(inode);
struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry);
const struct cred *old_cred;
err = ovl_want_write(dentry);
if (err)
goto out;
if (!value && !upperdentry) {
err = vfs_getxattr(realdentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
}
if (!upperdentry) {
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
realdentry = ovl_dentry_upper(dentry);
}
old_cred = ovl_override_creds(dentry->d_sb);
if (value)
err = vfs_setxattr(realdentry, name, value, size, flags);
else {
WARN_ON(flags != XATTR_REPLACE);
err = vfs_removexattr(realdentry, name);
}
revert_creds(old_cred);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags)
{
int err;
struct path realpath;
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
const struct cred *old_cred;
err = ovl_want_write(dentry);
if (err)
goto out;
if (!value && !OVL_TYPE_UPPER(type)) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
}
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
if (!OVL_TYPE_UPPER(type))
ovl_path_upper(dentry, &realpath);
old_cred = ovl_override_creds(dentry->d_sb);
if (value)
err = vfs_setxattr(realpath.dentry, name, value, size, flags);
else {
WARN_ON(flags != XATTR_REPLACE);
err = vfs_removexattr(realpath.dentry, name);
}
revert_creds(old_cred);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
}
static int ovl_symlink(struct inode *dir, struct dentry *dentry,
const char *link)
{
return ovl_create_object(dentry, S_IFLNK, 0, link);
}
static int ovl_link(struct dentry *old, struct inode *newdir,
struct dentry *new)
{
int err;
bool locked = false;
struct inode *inode;
err = ovl_want_write(old);
if (err)
goto out;
err = ovl_copy_up(old);
if (err)
goto out_drop_write;
if (ovl_is_metacopy_dentry(old)) {
err = ovl_set_redirect(old, false);
if (err)
goto out_drop_write;
}
err = ovl_nlink_start(old, &locked);
if (err)