// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "acl.h"
#include "xattr.h"
#include <linux/posix_acl.h>
static const char * const acl_types[] = {
[ACL_USER_OBJ] = "user_obj",
[ACL_USER] = "user",
[ACL_GROUP_OBJ] = "group_obj",
[ACL_GROUP] = "group",
[ACL_MASK] = "mask",
[ACL_OTHER] = "other",
NULL,
};
void bch2_acl_to_text(struct printbuf *out, const void *value, size_t size)
{
const void *p, *end = value + size;
if (!value ||
size < sizeof(bch_acl_header) ||
((bch_acl_header *)value)->a_version != cpu_to_le32(BCH_ACL_VERSION))
return;
p = value + sizeof(bch_acl_header);
while (p < end) {
const bch_acl_entry *in = p;
unsigned tag = le16_to_cpu(in->e_tag);
prt_str(out, acl_types[tag]);
switch (tag) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
p += sizeof(bch_acl_entry_short);
break;
case ACL_USER:
prt_printf(out, " uid %u", le32_to_cpu(in->e_id));
p += sizeof(bch_acl_entry);
break;
case ACL_GROUP:
prt_printf(out, " gid %u", le32_to_cpu(in->e_id));
p += sizeof(bch_acl_entry);
break;
}
prt_printf(out, " %o", le16_to_cpu(in->e_perm));
if (p != end)
prt_char(out, ' ');
}
}
#ifdef CONFIG_BCACHEFS_POSIX_ACL
#include "fs.h"
#include <linux/fs.h>
#include <linux/posix_acl_xattr.h>
#include <linux/sched.h>
#include <linux/slab.h>
static inline size_t bch2_acl_size(unsigned nr_short, unsigned nr_long)
{
return sizeof(bch_acl_header) +
sizeof(bch_acl_entry_short) * nr_short +
sizeof(bch_acl_entry) * nr_long;
}
static inline int acl_to_xattr_type(int type)
{
switch (type) {
case ACL_TYPE_ACCESS:
return KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS;
case ACL_TYPE_DEFAULT:
return KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT;
default:
BUG();
}
}
/*
* Convert from filesystem to in-memory representation.
*/
static struct posix_acl *bch2_acl_from_disk(struct btree_trans *trans,
const void *value, size_t size)
{
const void *p, *end = value + size;
struct posix_acl *acl;
struct posix_acl_entry *out;
unsigned count = 0;
int ret;
if (!value)
return NULL;
if (size < sizeof(bch_acl_header))
goto invalid;
if (((bch_acl_header *)value)->a_version !=
cpu_to_le32(BCH_ACL_VERSION))
goto invalid;
p = value + sizeof(bch_acl_header);
while (p < end) {
const bch_acl_entry *entry = p;
if (p + sizeof(bch_acl_entry_short) > end)
goto invalid;
switch (le16_to_cpu(entry->e_tag)) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
p += sizeof(bch_acl_entry_short);
break;
case ACL_USER:
case ACL_GROUP:
p += sizeof(bch_acl_entry);
break;
default:
goto invalid;
}
count++;
}
if (p > end)
goto invalid;
if (!count)
return NULL;
acl = allocate_dropping_locks(trans, ret,
posix_acl_alloc(count, _gfp));
if (!acl)
return ERR_PTR(-ENOMEM);
if (ret) {
kfree(acl);
return ERR_PTR(ret);
}
out = acl->a_entries;
p = value + sizeof(bch_acl_header);
while (p < end) {
const bch_acl_entry *in = p;
out->e_tag = le16_to_cpu(in->e_tag);
out->e_perm = le16_to_cpu(in->e_perm);
switch (out->e_tag) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
p += sizeof(bch_acl_entry_short);
break;
case ACL_USER:
out->e_uid = make_kuid(&init_user_ns,
le32_to_cpu(in->e_id));
p += sizeof(bch_acl_entry);
break;
case ACL_GROUP:
out->e_gid = make_kgid(&init_user_ns,
le32_to_cpu(in->e_id));
p += sizeof(bch_acl_entry);
break;
}
out++;
}
BUG_ON(out != acl->a_entries + acl->a_count);
return acl;
invalid:
pr_err("invalid acl entry");
return ERR_PTR(-EINVAL);
}
#define acl_for_each_entry(acl, acl_e) \
for (acl_e = acl->a_entries; \
acl_e < acl->a_entries + acl->a_count; \
acl_e++)
/*
* Convert from in-memory to filesystem representation.
*/
static struct bkey_i_xattr *
bch2_acl_to_xattr(struct btree_trans *trans,
const struct posix_acl *acl,
int type)
{
struct bkey_i_xattr *xattr;
bch_acl_header *acl_header;
const struct posix_acl_entry *acl_e;
void *outptr;
unsigned nr_short = 0, nr_long = 0, acl_len, u64s;
acl_for_each_entry(acl, acl_e) {
switch (acl_e->e_tag) {
case ACL_USER:
case ACL_GROUP:
nr_long++;
break;
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
nr_short++;
break;
default:
return ERR_PTR(-EINVAL);
}
}
acl_len = bch2_acl_size(nr_short, nr_long);
u64s = BKEY_U64s + xattr_val_u64s(0, acl_len);
if (u64s > U8_MAX)
return ERR_PTR(-E2BIG);
xattr = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
if (IS_ERR(xattr))
return xattr;
bkey_xattr_init(&xattr->k_i);
xattr->k.u64s = u64s;
xattr->v.x_type = acl_to_xattr_type(type);
xattr->v.x_name_len = 0;
xattr->v.x_val_len = cpu_to_le16(acl_len);
acl_header = xattr_val(&xattr->v);
acl_header->a_version = cpu_to_le32(BCH_ACL_VERSION);
outptr = (void *) acl_header + sizeof(*acl_header);
acl_for_each_entry(acl, acl_e) {
bch_acl_entry *entry = outptr;
entry->e_tag = cpu_to_le16(acl_e->e_tag);
entry->e_perm = cpu_to_le16(acl_e->e_perm);
switch (acl_e->e_tag) {
case ACL_USER:
entry->e_id = cpu_to_le32(
from_kuid(&init_user_ns, acl_e->e_uid));
outptr += sizeof(bch_acl_entry);
break;
case ACL_GROUP:
entry->e_id = cpu_to_le32(
from_kgid(&init_user_ns, acl_e->e_gid));
outptr += sizeof(bch_acl_entry);
break;
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
outptr += sizeof(bch_acl_entry_short);
break;
}
}
BUG_ON(outptr != xattr_val(&xattr->v) + acl_len);
return xattr;
}
struct posix_acl *bch2_get_acl(struct inode *vinode, int type, bool rcu)
{
struct bch_inode_info *inode = to_bch_ei(vinode);
struct bch_fs *c = inode->v.i_sb->s_fs_info;
struct bch_hash_info hash = bch2_hash_info_init(c, &inode->ei_inode);
struct xattr_search_key search = X_SEARCH(acl_to_xattr_type(type), "", 0);
struct btree_iter iter = { NULL };
struct posix_acl *acl = NULL;
if (rcu)
return ERR_PTR(-ECHILD);
struct btree_trans *trans = bch2_trans_get(c);
retry:
bch2_trans_begin(trans);
struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
&hash, inode_inum(inode), &search, 0);
int ret = bkey_err(k);
if (ret)
goto err;
struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),
le16_to_cpu(xattr.v->x_val_len));
ret = PTR_ERR_OR_ZERO(acl);
err:
if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
goto retry;
if (ret)
acl = !bch2_err_matches(ret, ENOENT) ? ERR_PTR(ret) : NULL;
if (!IS_ERR_OR_NULL(acl))
set_cached_acl(&inode->v, type, acl);
bch2_trans_iter_exit(trans, &iter);
bch2_trans_put(trans);
return acl;
}
int bch2_set_acl_trans(struct btree_trans *trans, subvol_inum inum,
struct bch_inode_unpacked *inode_u,
struct posix_acl *acl, int type)
{
struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode_u);
int ret;
if (type == ACL_TYPE_DEFAULT &&
!S_ISDIR(inode_u->bi_mode))
return acl ? -EACCES : 0;
if (acl) {
struct bkey_i_xattr *xattr =
bch2_acl_to_xattr(trans, acl, type);
if (IS_ERR(xattr))
return PTR_ERR(xattr);
ret = bch2_hash_set(trans, bch2_xattr_hash_desc, &hash_info,
inum, &xattr->k_i, 0);
} else {
struct xattr_search_key search =
X_SEARCH(acl_to_xattr_type(type), "", 0);
ret = bch2_hash_delete(trans, bch2_xattr_hash_desc, &hash_info,
inum, &search);
}
return bch2_err_matches(ret, ENOENT) ? 0 : ret;
}
int bch2_set_acl(struct mnt_idmap *idmap,
struct dentry *dentry,
struct posix_acl *_acl, int type)
{
struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
struct bch_fs *c = inode->v.i_sb->s_fs_info;
struct btree_iter inode_iter = { NULL };
struct bch_inode_unpacked inode_u;
struct posix_acl *acl;
umode_t mode;
int ret;
mutex_lock(&inode->ei_update_lock);
struct btree_trans *trans = bch2_trans_get(c);
retry:
bch2_trans_begin(trans);
acl = _acl;
ret = bch2_subvol_is_ro_trans(trans, inode->ei_inum.subvol) ?:
bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),
BTREE_ITER_intent);
if (ret)
goto btree_err;
mode = inode_u.bi_mode;
if (type == ACL_TYPE_ACCESS) {
ret = posix_acl_update_mode(idmap, &inode->v, &mode, &acl);
if (ret)
goto btree_err;
}
ret = bch2_set_acl_trans(trans, inode_inum(inode), &inode_u, acl, type);
if (ret)
goto btree_err;
inode_u.bi_ctime = bch2_current_time(c);
inode_u.bi_mode = mode;
ret = bch2_inode_write(trans, &inode_iter, &inode_u) ?:
bch2_trans_commit(trans, NULL, NULL, 0);
btree_err:
bch2_trans_iter_exit(trans, &inode_iter);
if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
goto retry;
if (unlikely(ret))
goto err;
bch2_inode_update_after_write(trans, inode, &inode_u,
ATTR_CTIME|ATTR_MODE);
set_cached_acl(&inode->v, type, acl);
err:
bch2_trans_put(trans);
mutex_unlock(&inode->ei_update_lock);
return ret;
}
int bch2_acl_chmod(struct btree_trans *trans, subvol_inum inum,
struct bch_inode_unpacked *inode,
umode_t mode,
struct posix_acl **new_acl)
{
struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode);
struct xattr_search_key search = X_SEARCH(KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS, "", 0);
struct btree_iter iter;
struct posix_acl *acl = NULL;
struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
&hash_info, inum, &search, BTREE_ITER_intent);
int ret = bkey_err(k);
if (ret)
return bch2_err_matches(ret, ENOENT) ? 0 : ret;
struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),
le16_to_cpu(xattr.v->x_val_len));
ret = PTR_ERR_OR_ZERO(acl);
if (ret)
goto err;
ret = allocate_dropping_locks_errcode(trans, __posix_acl_chmod(&acl, _gfp, mode));
if (ret)
goto err;
struct bkey_i_xattr *new = bch2_acl_to_xattr(trans, acl, ACL_TYPE_ACCESS);
ret = PTR_ERR_OR_ZERO(new);
if (ret)
goto err;
new->k.p = iter.pos;
ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
*new_acl = acl;
acl = NULL;
err:
bch2_trans_iter_exit(trans, &iter);
if (!IS_ERR_OR_NULL(acl))
kfree(acl);
return ret;
}
#endif /* CONFIG_BCACHEFS_POSIX_ACL */
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