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_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_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct path realpath;
enum ovl_path_type type;
if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
ovl_is_private_xattr(name))
return -ENODATA;
type = ovl_path_real(dentry, &realpath);
if (type == OVL_PATH_LOWER) {
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
if (err < 0)
return err;
err = ovl_copy_up(dentry);
if (err)
return err;
ovl_path_upper(dentry, &realpath);
}
return vfs_removexattr(realpath.dentry, name);
}
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;
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);
}
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);
}
/**
* ovl_statfs
* @sb: The overlayfs super block
* @buf: The struct kstatfs to fill in with stats
*
* Get the filesystem statistics. As writes always target the upper layer
* filesystem pass the statfs to the same filesystem.
*/
static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct dentry *root_dentry = dentry->d_sb->s_root;
struct path path;
ovl_path_upper(root_dentry, &path);
if (!path.dentry->d_sb->s_op->statfs)
return -ENOSYS;
return path.dentry->d_sb->s_op->statfs(path.dentry, buf);
}
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path)
{
enum ovl_path_type type = ovl_path_type(dentry);
if (!OVL_TYPE_UPPER(type))
ovl_path_lower(dentry, path);
else
ovl_path_upper(dentry, path);
return type;
}
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path)
{
enum ovl_path_type type = ovl_path_type(dentry);
if (type == OVL_PATH_LOWER)
ovl_path_lower(dentry, path);
else
ovl_path_upper(dentry, path);
return type;
}
/**
* ovl_statfs
* @sb: The overlayfs super block
* @buf: The struct kstatfs to fill in with stats
*
* Get the filesystem statistics. As writes always target the upper layer
* filesystem pass the statfs to the same filesystem.
*/
static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
struct dentry *root_dentry = dentry->d_sb->s_root;
struct path path;
int err;
ovl_path_upper(root_dentry, &path);
err = vfs_statfs(&path, buf);
if (!err) {
buf->f_namelen = max(buf->f_namelen, ofs->lower_namelen);
buf->f_type = OVERLAYFS_SUPER_MAGIC;
}
return err;
}
static struct file *ovl_open(struct dentry *dentry, struct file *file,
const struct cred *cred)
{
int err;
struct path realpath;
enum ovl_path_type type;
type = ovl_path_real(dentry, &realpath);
if (ovl_open_need_copy_up(file->f_flags, type, realpath.dentry)) {
if (file->f_flags & O_TRUNC)
err = ovl_copy_up_truncate(dentry, 0);
else
err = ovl_copy_up(dentry);
if (err)
return ERR_PTR(err);
ovl_path_upper(dentry, &realpath);
}
return vfs_open(&realpath, file, cred);
}
static struct dentry *ovl_clear_empty(struct dentry *dentry,
struct list_head *list)
{
struct dentry *workdir = ovl_workdir(dentry);
struct inode *wdir = workdir->d_inode;
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
struct inode *udir = upperdir->d_inode;
struct path upperpath;
struct dentry *upper;
struct dentry *opaquedir;
struct kstat stat;
int err;
if (WARN_ON(!workdir))
return ERR_PTR(-EROFS);
err = ovl_lock_rename_workdir(workdir, upperdir);
if (err)
goto out;
ovl_path_upper(dentry, &upperpath);
err = vfs_getattr(&upperpath, &stat);
if (err)
goto out_unlock;
err = -ESTALE;
if (!S_ISDIR(stat.mode))
goto out_unlock;
upper = upperpath.dentry;
if (upper->d_parent->d_inode != udir)
goto out_unlock;
opaquedir = ovl_lookup_temp(workdir, dentry);
err = PTR_ERR(opaquedir);
if (IS_ERR(opaquedir))
goto out_unlock;
err = ovl_create_real(wdir, opaquedir,
&(struct cattr){.mode = stat.mode}, NULL, true);
int ovl_update_time(struct inode *inode, struct timespec *ts, int flags)
{
struct dentry *alias;
struct path upperpath;
if (!(flags & S_ATIME))
return 0;
alias = d_find_any_alias(inode);
if (!alias)
return 0;
ovl_path_upper(alias, &upperpath);
if (upperpath.dentry) {
touch_atime(&upperpath);
inode->i_atime = d_inode(upperpath.dentry)->i_atime;
}
dput(alias);
return 0;
}
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 struct dentry *ovl_clear_empty(struct dentry *dentry,
struct list_head *list)
{
struct dentry *workdir = ovl_workdir(dentry);
struct inode *wdir = workdir->d_inode;
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
struct inode *udir = upperdir->d_inode;
struct path upperpath;
struct dentry *upper;
struct dentry *opaquedir;
struct kstat stat;
int err;
if (WARN_ON(!workdir))
return ERR_PTR(-EROFS);
err = ovl_lock_rename_workdir(workdir, upperdir);
if (err)
goto out;
ovl_path_upper(dentry, &upperpath);
err = vfs_getattr(&upperpath, &stat,
STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
if (err)
goto out_unlock;
err = -ESTALE;
if (!S_ISDIR(stat.mode))
goto out_unlock;
upper = upperpath.dentry;
if (upper->d_parent->d_inode != udir)
goto out_unlock;
opaquedir = ovl_create_temp(workdir, OVL_CATTR(stat.mode));
err = PTR_ERR(opaquedir);
if (IS_ERR(opaquedir))
goto out_unlock;
err = ovl_copy_xattr(upper, opaquedir);
if (err)
goto out_cleanup;
err = ovl_set_opaque(dentry, opaquedir);
if (err)
goto out_cleanup;
inode_lock(opaquedir->d_inode);
err = ovl_set_attr(opaquedir, &stat);
inode_unlock(opaquedir->d_inode);
if (err)
goto out_cleanup;
err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE);
if (err)
goto out_cleanup;
ovl_cleanup_whiteouts(upper, list);
ovl_cleanup(wdir, upper);
unlock_rename(workdir, upperdir);
/* dentry's upper doesn't match now, get rid of it */
d_drop(dentry);
return opaquedir;
out_cleanup:
ovl_cleanup(wdir, opaquedir);
dput(opaquedir);
out_unlock:
unlock_rename(workdir, upperdir);
out:
return ERR_PTR(err);
}
static struct dentry *ovl_clear_empty(struct dentry *dentry,
struct list_head *list)
{
struct dentry *workdir = ovl_workdir(dentry);
struct inode *wdir = workdir->d_inode;
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
struct inode *udir = upperdir->d_inode;
struct path upperpath;
struct dentry *upper;
struct dentry *opaquedir;
struct kstat stat;
int err;
err = ovl_lock_rename_workdir(workdir, upperdir);
if (err)
goto out;
ovl_path_upper(dentry, &upperpath);
err = vfs_getattr(&upperpath, &stat);
if (err)
goto out_unlock;
err = -ESTALE;
if (!S_ISDIR(stat.mode))
goto out_unlock;
upper = upperpath.dentry;
if (upper->d_parent->d_inode != udir)
goto out_unlock;
opaquedir = ovl_lookup_temp(workdir, dentry);
err = PTR_ERR(opaquedir);
if (IS_ERR(opaquedir))
goto out_unlock;
err = ovl_create_real(wdir, opaquedir, &stat, NULL, NULL, true);
if (err)
goto out_dput;
err = ovl_copy_xattr(upper, opaquedir);
if (err)
goto out_cleanup;
err = ovl_set_opaque(opaquedir);
if (err)
goto out_cleanup;
mutex_lock(&opaquedir->d_inode->i_mutex);
err = ovl_set_attr(opaquedir, &stat);
mutex_unlock(&opaquedir->d_inode->i_mutex);
if (err)
goto out_cleanup;
err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE);
if (err)
goto out_cleanup;
ovl_cleanup_whiteouts(upper, list);
ovl_cleanup(wdir, upper);
unlock_rename(workdir, upperdir);
/* dentry's upper doesn't match now, get rid of it */
d_drop(dentry);
return opaquedir;
out_cleanup:
ovl_cleanup(wdir, opaquedir);
out_dput:
dput(opaquedir);
out_unlock:
unlock_rename(workdir, upperdir);
out:
return ERR_PTR(err);
}
