linux-stable/fs/bcachefs/acl.c
Kent Overstreet 2d594dfb53 bcachefs: Split out btree_trigger_flags
The trigger flags really belong with individual btree_insert_entries,
not the transaction commit flags - this splits out those  flags and
unifies them with the BCH_BUCKET_MARK flags. Todo - split out
btree_trigger.c from buckets.c

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:33 -04:00

391 lines
8.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifdef CONFIG_BCACHEFS_POSIX_ACL
#include "bcachefs.h"
#include <linux/fs.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "acl.h"
#include "fs.h"
#include "xattr.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(const void *value, size_t size)
{
const void *p, *end = value + size;
struct posix_acl *acl;
struct posix_acl_entry *out;
unsigned count = 0;
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 = posix_acl_alloc(count, GFP_KERNEL);
if (!acl)
return ERR_PTR(-ENOMEM);
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 mnt_idmap *idmap,
struct dentry *dentry, 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_trans trans;
struct btree_iter *iter;
struct bkey_s_c_xattr xattr;
struct posix_acl *acl = NULL;
bch2_trans_init(&trans, c, 0, 0);
retry:
bch2_trans_begin(&trans);
iter = bch2_hash_lookup(&trans, bch2_xattr_hash_desc,
&inode->ei_str_hash, inode->v.i_ino,
&X_SEARCH(acl_to_xattr_type(type), "", 0),
0);
if (IS_ERR(iter)) {
if (PTR_ERR(iter) == -EINTR)
goto retry;
if (PTR_ERR(iter) != -ENOENT)
acl = ERR_CAST(iter);
goto out;
}
xattr = bkey_s_c_to_xattr(bch2_btree_iter_peek_slot(iter));
acl = bch2_acl_from_disk(xattr_val(xattr.v),
le16_to_cpu(xattr.v->x_val_len));
if (!IS_ERR(acl))
set_cached_acl(&inode->v, type, acl);
out:
bch2_trans_exit(&trans);
return acl;
}
int bch2_set_acl_trans(struct btree_trans *trans,
struct bch_inode_unpacked *inode_u,
const struct bch_hash_info *hash_info,
struct posix_acl *acl, int type)
{
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,
inode_u->bi_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,
inode_u->bi_inum, &search);
}
return 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_trans trans;
struct btree_iter *inode_iter;
struct bch_inode_unpacked inode_u;
struct posix_acl *acl;
umode_t mode;
int ret;
mutex_lock(&inode->ei_update_lock);
bch2_trans_init(&trans, c, 0, 0);
retry:
bch2_trans_begin(&trans);
acl = _acl;
inode_iter = bch2_inode_peek(&trans, &inode_u, inode->v.i_ino,
BTREE_ITER_INTENT);
ret = PTR_ERR_OR_ZERO(inode_iter);
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 err;
}
ret = bch2_set_acl_trans(&trans, &inode_u,
&inode->ei_str_hash,
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,
&inode->ei_journal_seq,
BTREE_INSERT_NOUNLOCK);
btree_err:
if (ret == -EINTR)
goto retry;
if (unlikely(ret))
goto err;
bch2_inode_update_after_write(c, inode, &inode_u,
ATTR_CTIME|ATTR_MODE);
set_cached_acl(&inode->v, type, acl);
err:
bch2_trans_exit(&trans);
mutex_unlock(&inode->ei_update_lock);
return ret;
}
int bch2_acl_chmod(struct btree_trans *trans,
struct bch_inode_info *inode,
umode_t mode,
struct posix_acl **new_acl)
{
struct btree_iter *iter;
struct bkey_s_c_xattr xattr;
struct bkey_i_xattr *new;
struct posix_acl *acl;
int ret = 0;
iter = bch2_hash_lookup(trans, bch2_xattr_hash_desc,
&inode->ei_str_hash, inode->v.i_ino,
&X_SEARCH(KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS, "", 0),
BTREE_ITER_INTENT);
if (IS_ERR(iter))
return PTR_ERR(iter) != -ENOENT ? PTR_ERR(iter) : 0;
xattr = bkey_s_c_to_xattr(bch2_btree_iter_peek_slot(iter));
acl = bch2_acl_from_disk(xattr_val(xattr.v),
le16_to_cpu(xattr.v->x_val_len));
if (IS_ERR_OR_NULL(acl))
return PTR_ERR(acl);
ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
if (ret)
goto err;
new = bch2_acl_to_xattr(trans, acl, ACL_TYPE_ACCESS);
if (IS_ERR(new)) {
ret = PTR_ERR(new);
goto err;
}
new->k.p = iter->pos;
bch2_trans_update(trans, iter, &new->k_i, 0);
*new_acl = acl;
acl = NULL;
err:
kfree(acl);
return ret;
}
#endif /* CONFIG_BCACHEFS_POSIX_ACL */