/*
* BKL held by caller.
* dentry->d_inode->i_mutex locked
*/
ssize_t unionfs_listxattr(struct dentry *dentry, char *list, size_t size)
{
struct dentry *lower_dentry = NULL;
struct dentry *parent;
int err = -EOPNOTSUPP;
char *encoded_list = NULL;
bool valid;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate(dentry, parent, false);
if (unlikely(!valid)) {
err = -ESTALE;
goto out;
}
lower_dentry = unionfs_lower_dentry(dentry);
encoded_list = list;
err = vfs_listxattr(lower_dentry, encoded_list, size);
out:
unionfs_check_dentry(dentry);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return err;
}
/*
* Extended attribute LIST operations
*/
static ssize_t
listxattr(struct dentry *d, char __user *list, size_t size)
{
ssize_t error;
char *klist = NULL;
if (size) {
if (size > XATTR_LIST_MAX)
size = XATTR_LIST_MAX;
klist = kmalloc(size, GFP_KERNEL);
if (!klist)
return -ENOMEM;
}
error = vfs_listxattr(d, klist, size);
if (error > 0) {
if (size && copy_to_user(list, klist, error))
error = -EFAULT;
} else if (error == -ERANGE && size >= XATTR_LIST_MAX) {
/* The file system tried to returned a list bigger
than XATTR_LIST_MAX bytes. Not possible. */
error = -E2BIG;
}
kfree(klist);
return error;
}
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
ssize_t res;
int off;
res = vfs_listxattr(ovl_dentry_real(dentry), list, size);
if (res <= 0 || size == 0)
return res;
if (ovl_path_type(dentry->d_parent) != OVL_PATH_MERGE)
return res;
/* filter out private xattrs */
for (off = 0; off < res;) {
char *s = list + off;
size_t slen = strlen(s) + 1;
BUG_ON(off + slen > res);
if (ovl_is_private_xattr(s)) {
res -= slen;
memmove(s, s + slen, res - off);
} else {
off += slen;
}
}
return res;
}
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
struct path realpath;
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
ssize_t res;
size_t len;
char *s;
res = vfs_listxattr(realpath.dentry, list, size);
if (res <= 0 || size == 0)
return res;
if (!ovl_need_xattr_filter(dentry, type))
return res;
/* filter out private xattrs */
for (s = list, len = res; len;) {
size_t slen = strnlen(s, len) + 1;
/* underlying fs providing us with an broken xattr list? */
if (WARN_ON(slen > len))
return -EIO;
len -= slen;
if (ovl_is_private_xattr(s)) {
res -= slen;
memmove(s, s + slen, len);
} else {
s += slen;
}
}
return res;
}
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
struct dentry *realdentry = ovl_dentry_real(dentry);
ssize_t res;
size_t len;
char *s;
const struct cred *old_cred;
old_cred = ovl_override_creds(dentry->d_sb);
res = vfs_listxattr(realdentry, list, size);
revert_creds(old_cred);
if (res <= 0 || size == 0)
return res;
/* filter out private xattrs */
for (s = list, len = res; len;) {
size_t slen = strnlen(s, len) + 1;
/* underlying fs providing us with an broken xattr list? */
if (WARN_ON(slen > len))
return -EIO;
len -= slen;
if (!ovl_can_list(s)) {
res -= slen;
memmove(s, s + slen, len);
} else {
s += slen;
}
}
return res;
}
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
struct path realpath;
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
ssize_t res;
int off;
res = vfs_listxattr(realpath.dentry, list, size);
if (res <= 0 || size == 0)
return res;
if (!ovl_need_xattr_filter(dentry, type))
return res;
/* filter out private xattrs */
for (off = 0; off < res;) {
char *s = list + off;
size_t slen = strlen(s) + 1;
BUG_ON(off + slen > res);
if (ovl_is_private_xattr(s)) {
res -= slen;
memmove(s, s + slen, res - off);
} else {
off += slen;
}
}
return res;
}
static ssize_t diaryfs_listxattr(struct dentry * dentry, char * buffer, size_t buffer_size) {
int err;
struct dentry * lower_dentry;
struct path lower_path;
diaryfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
if (!lower_dentry->d_inode->i_op->listxattr) {
err = -EOPNOTSUPP;
goto out;
}
err = vfs_listxattr(lower_dentry, buffer, buffer_size);
if (err)
goto out;
fsstack_copy_attr_atime(dentry->d_inode, lower_path.dentry->d_inode);
out:
diaryfs_put_lower_path(dentry, &lower_path);
return err;
}
static ssize_t
amfs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
int err;
struct dentry *lower_dentry;
struct path lower_path;
amfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
if (!lower_dentry->d_inode->i_op ||
!lower_dentry->d_inode->i_op->listxattr) {
err = -EINVAL;
goto out;
}
err = vfs_listxattr(lower_dentry,
buffer, buffer_size);
out:
amfs_put_lower_path(dentry, &lower_path);
return err;
}
/* copyup all extended attrs for a given dentry */
static int copyup_xattrs(struct dentry *old_lower_dentry,
struct dentry *new_lower_dentry)
{
int err = 0;
ssize_t list_size = -1;
char *name_list = NULL;
char *attr_value = NULL;
char *name_list_buf = NULL;
/* query the actual size of the xattr list */
list_size = vfs_listxattr(old_lower_dentry, NULL, 0);
if (list_size <= 0) {
err = list_size;
goto out;
}
/* allocate space for the actual list */
name_list = unionfs_xattr_alloc(list_size + 1, XATTR_LIST_MAX);
if (unlikely(!name_list || IS_ERR(name_list))) {
err = PTR_ERR(name_list);
goto out;
}
name_list_buf = name_list; /* save for kfree at end */
/* now get the actual xattr list of the source file */
list_size = vfs_listxattr(old_lower_dentry, name_list, list_size);
if (list_size <= 0) {
err = list_size;
goto out;
}
/* allocate space to hold each xattr's value */
attr_value = unionfs_xattr_alloc(XATTR_SIZE_MAX, XATTR_SIZE_MAX);
if (unlikely(!attr_value || IS_ERR(attr_value))) {
err = PTR_ERR(name_list);
goto out;
}
/* in a loop, get and set each xattr from src to dst file */
while (*name_list) {
ssize_t size;
/* Lock here since vfs_getxattr doesn't lock for us */
mutex_lock(&old_lower_dentry->d_inode->i_mutex);
size = vfs_getxattr(old_lower_dentry, name_list,
attr_value, XATTR_SIZE_MAX);
mutex_unlock(&old_lower_dentry->d_inode->i_mutex);
if (size < 0) {
err = size;
goto out;
}
if (size > XATTR_SIZE_MAX) {
err = -E2BIG;
goto out;
}
/* Don't lock here since vfs_setxattr does it for us. */
err = vfs_setxattr(new_lower_dentry, name_list, attr_value,
size, 0);
/*
* Selinux depends on "security.*" xattrs, so to maintain
* the security of copied-up files, if Selinux is active,
* then we must copy these xattrs as well. So we need to
* temporarily get FOWNER privileges.
* XXX: move entire copyup code to SIOQ.
*/
if (err == -EPERM && !capable(CAP_FOWNER)) {
cap_raise(current->cap_effective, CAP_FOWNER);
err = vfs_setxattr(new_lower_dentry, name_list,
attr_value, size, 0);
cap_lower(current->cap_effective, CAP_FOWNER);
}
if (err < 0)
goto out;
name_list += strlen(name_list) + 1;
}
out:
unionfs_xattr_kfree(name_list_buf);
unionfs_xattr_kfree(attr_value);
/* Ignore if xattr isn't supported */
if (err == -ENOTSUPP || err == -EOPNOTSUPP)
err = 0;
return err;
}
/* copyup all extended attrs for a given dentry */
static int copyup_xattrs(struct dentry *old_hidden_dentry,
struct dentry *new_hidden_dentry)
{
int err = 0;
ssize_t list_size = -1;
char *name_list = NULL;
char *attr_value = NULL;
char *name_list_orig = NULL;
list_size = vfs_listxattr(old_hidden_dentry, NULL, 0);
if (list_size <= 0) {
err = list_size;
goto out;
}
name_list = unionfs_xattr_alloc(list_size + 1, XATTR_LIST_MAX);
if (!name_list || IS_ERR(name_list)) {
err = PTR_ERR(name_list);
goto out;
}
list_size = vfs_listxattr(old_hidden_dentry, name_list, list_size);
attr_value = unionfs_xattr_alloc(XATTR_SIZE_MAX, XATTR_SIZE_MAX);
if (!attr_value || IS_ERR(attr_value)) {
err = PTR_ERR(name_list);
goto out;
}
name_list_orig = name_list;
while (*name_list) {
ssize_t size;
/* Lock here since vfs_getxattr doesn't lock for us */
mutex_lock(&old_hidden_dentry->d_inode->i_mutex);
size = vfs_getxattr(old_hidden_dentry, name_list,
attr_value, XATTR_SIZE_MAX);
mutex_unlock(&old_hidden_dentry->d_inode->i_mutex);
if (size < 0) {
err = size;
goto out;
}
if (size > XATTR_SIZE_MAX) {
err = -E2BIG;
goto out;
}
/* Don't lock here since vfs_setxattr does it for us. */
err = vfs_setxattr(new_hidden_dentry, name_list, attr_value,
size, 0);
if (err < 0)
goto out;
name_list += strlen(name_list) + 1;
}
out:
name_list = name_list_orig;
if (name_list)
unionfs_xattr_free(name_list, list_size + 1);
if (attr_value)
unionfs_xattr_free(attr_value, XATTR_SIZE_MAX);
/* It is no big deal if this fails, we just roll with the punches. */
if (err == -ENOTSUPP || err == -EOPNOTSUPP)
err = 0;
return err;
}
