1
linux/fs/bcachefs/fs-common.c
Sasha Finkelstein 4645855df0 bcachefs: Hook up RENAME_WHITEOUT in rename.
This is needed for overlayfs, which is used by container managers.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-09-21 11:35:20 -04:00

551 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "acl.h"
#include "btree_update.h"
#include "dirent.h"
#include "fs-common.h"
#include "inode.h"
#include "subvolume.h"
#include "xattr.h"
#include <linux/posix_acl.h>
static inline int is_subdir_for_nlink(struct bch_inode_unpacked *inode)
{
return S_ISDIR(inode->bi_mode) && !inode->bi_subvol;
}
int bch2_create_trans(struct btree_trans *trans,
subvol_inum dir,
struct bch_inode_unpacked *dir_u,
struct bch_inode_unpacked *new_inode,
const struct qstr *name,
uid_t uid, gid_t gid, umode_t mode, dev_t rdev,
struct posix_acl *default_acl,
struct posix_acl *acl,
subvol_inum snapshot_src,
unsigned flags)
{
struct bch_fs *c = trans->c;
struct btree_iter dir_iter = { NULL };
struct btree_iter inode_iter = { NULL };
subvol_inum new_inum = dir;
u64 now = bch2_current_time(c);
u64 cpu = raw_smp_processor_id();
u64 dir_target;
u32 snapshot;
unsigned dir_type = mode_to_type(mode);
int ret;
ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot);
if (ret)
goto err;
ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir,
BTREE_ITER_intent|BTREE_ITER_with_updates);
if (ret)
goto err;
if (!(flags & BCH_CREATE_SNAPSHOT)) {
/* Normal create path - allocate a new inode: */
bch2_inode_init_late(new_inode, now, uid, gid, mode, rdev, dir_u);
if (flags & BCH_CREATE_TMPFILE)
new_inode->bi_flags |= BCH_INODE_unlinked;
ret = bch2_inode_create(trans, &inode_iter, new_inode, snapshot, cpu);
if (ret)
goto err;
snapshot_src = (subvol_inum) { 0 };
} else {
/*
* Creating a snapshot - we're not allocating a new inode, but
* we do have to lookup the root inode of the subvolume we're
* snapshotting and update it (in the new snapshot):
*/
if (!snapshot_src.inum) {
/* Inode wasn't specified, just snapshot: */
struct bch_subvolume s;
ret = bch2_subvolume_get(trans, snapshot_src.subvol, true,
BTREE_ITER_cached, &s);
if (ret)
goto err;
snapshot_src.inum = le64_to_cpu(s.inode);
}
ret = bch2_inode_peek(trans, &inode_iter, new_inode, snapshot_src,
BTREE_ITER_intent);
if (ret)
goto err;
if (new_inode->bi_subvol != snapshot_src.subvol) {
/* Not a subvolume root: */
ret = -EINVAL;
goto err;
}
/*
* If we're not root, we have to own the subvolume being
* snapshotted:
*/
if (uid && new_inode->bi_uid != uid) {
ret = -EPERM;
goto err;
}
flags |= BCH_CREATE_SUBVOL;
}
new_inum.inum = new_inode->bi_inum;
dir_target = new_inode->bi_inum;
if (flags & BCH_CREATE_SUBVOL) {
u32 new_subvol, dir_snapshot;
ret = bch2_subvolume_create(trans, new_inode->bi_inum,
dir.subvol,
snapshot_src.subvol,
&new_subvol, &snapshot,
(flags & BCH_CREATE_SNAPSHOT_RO) != 0);
if (ret)
goto err;
new_inode->bi_parent_subvol = dir.subvol;
new_inode->bi_subvol = new_subvol;
new_inum.subvol = new_subvol;
dir_target = new_subvol;
dir_type = DT_SUBVOL;
ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &dir_snapshot);
if (ret)
goto err;
bch2_btree_iter_set_snapshot(&dir_iter, dir_snapshot);
ret = bch2_btree_iter_traverse(&dir_iter);
if (ret)
goto err;
}
if (!(flags & BCH_CREATE_SNAPSHOT)) {
if (default_acl) {
ret = bch2_set_acl_trans(trans, new_inum, new_inode,
default_acl, ACL_TYPE_DEFAULT);
if (ret)
goto err;
}
if (acl) {
ret = bch2_set_acl_trans(trans, new_inum, new_inode,
acl, ACL_TYPE_ACCESS);
if (ret)
goto err;
}
}
if (!(flags & BCH_CREATE_TMPFILE)) {
struct bch_hash_info dir_hash = bch2_hash_info_init(c, dir_u);
u64 dir_offset;
if (is_subdir_for_nlink(new_inode))
dir_u->bi_nlink++;
dir_u->bi_mtime = dir_u->bi_ctime = now;
ret = bch2_inode_write(trans, &dir_iter, dir_u);
if (ret)
goto err;
ret = bch2_dirent_create(trans, dir, &dir_hash,
dir_type,
name,
dir_target,
&dir_offset,
STR_HASH_must_create|BTREE_ITER_with_updates);
if (ret)
goto err;
new_inode->bi_dir = dir_u->bi_inum;
new_inode->bi_dir_offset = dir_offset;
}
inode_iter.flags &= ~BTREE_ITER_all_snapshots;
bch2_btree_iter_set_snapshot(&inode_iter, snapshot);
ret = bch2_btree_iter_traverse(&inode_iter) ?:
bch2_inode_write(trans, &inode_iter, new_inode);
err:
bch2_trans_iter_exit(trans, &inode_iter);
bch2_trans_iter_exit(trans, &dir_iter);
return ret;
}
int bch2_link_trans(struct btree_trans *trans,
subvol_inum dir, struct bch_inode_unpacked *dir_u,
subvol_inum inum, struct bch_inode_unpacked *inode_u,
const struct qstr *name)
{
struct bch_fs *c = trans->c;
struct btree_iter dir_iter = { NULL };
struct btree_iter inode_iter = { NULL };
struct bch_hash_info dir_hash;
u64 now = bch2_current_time(c);
u64 dir_offset = 0;
int ret;
if (dir.subvol != inum.subvol)
return -EXDEV;
ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_intent);
if (ret)
return ret;
inode_u->bi_ctime = now;
ret = bch2_inode_nlink_inc(inode_u);
if (ret)
goto err;
ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
if (ret)
goto err;
if (bch2_reinherit_attrs(inode_u, dir_u)) {
ret = -EXDEV;
goto err;
}
dir_u->bi_mtime = dir_u->bi_ctime = now;
dir_hash = bch2_hash_info_init(c, dir_u);
ret = bch2_dirent_create(trans, dir, &dir_hash,
mode_to_type(inode_u->bi_mode),
name, inum.inum, &dir_offset,
STR_HASH_must_create);
if (ret)
goto err;
inode_u->bi_dir = dir.inum;
inode_u->bi_dir_offset = dir_offset;
ret = bch2_inode_write(trans, &dir_iter, dir_u) ?:
bch2_inode_write(trans, &inode_iter, inode_u);
err:
bch2_trans_iter_exit(trans, &dir_iter);
bch2_trans_iter_exit(trans, &inode_iter);
return ret;
}
int bch2_unlink_trans(struct btree_trans *trans,
subvol_inum dir,
struct bch_inode_unpacked *dir_u,
struct bch_inode_unpacked *inode_u,
const struct qstr *name,
bool deleting_subvol)
{
struct bch_fs *c = trans->c;
struct btree_iter dir_iter = { NULL };
struct btree_iter dirent_iter = { NULL };
struct btree_iter inode_iter = { NULL };
struct bch_hash_info dir_hash;
subvol_inum inum;
u64 now = bch2_current_time(c);
struct bkey_s_c k;
int ret;
ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
if (ret)
goto err;
dir_hash = bch2_hash_info_init(c, dir_u);
ret = bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
name, &inum, BTREE_ITER_intent);
if (ret)
goto err;
ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
BTREE_ITER_intent);
if (ret)
goto err;
if (!deleting_subvol && S_ISDIR(inode_u->bi_mode)) {
ret = bch2_empty_dir_trans(trans, inum);
if (ret)
goto err;
}
if (deleting_subvol && !inode_u->bi_subvol) {
ret = -BCH_ERR_ENOENT_not_subvol;
goto err;
}
if (inode_u->bi_subvol) {
/* Recursive subvolume destroy not allowed (yet?) */
ret = bch2_subvol_has_children(trans, inode_u->bi_subvol);
if (ret)
goto err;
}
if (deleting_subvol || inode_u->bi_subvol) {
ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
if (ret)
goto err;
k = bch2_btree_iter_peek_slot(&dirent_iter);
ret = bkey_err(k);
if (ret)
goto err;
/*
* If we're deleting a subvolume, we need to really delete the
* dirent, not just emit a whiteout in the current snapshot:
*/
bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot);
ret = bch2_btree_iter_traverse(&dirent_iter);
if (ret)
goto err;
} else {
bch2_inode_nlink_dec(trans, inode_u);
}
if (inode_u->bi_dir == dirent_iter.pos.inode &&
inode_u->bi_dir_offset == dirent_iter.pos.offset) {
inode_u->bi_dir = 0;
inode_u->bi_dir_offset = 0;
}
dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
ret = bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
&dir_hash, &dirent_iter,
BTREE_UPDATE_internal_snapshot_node) ?:
bch2_inode_write(trans, &dir_iter, dir_u) ?:
bch2_inode_write(trans, &inode_iter, inode_u);
err:
bch2_trans_iter_exit(trans, &inode_iter);
bch2_trans_iter_exit(trans, &dirent_iter);
bch2_trans_iter_exit(trans, &dir_iter);
return ret;
}
bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
struct bch_inode_unpacked *src_u)
{
u64 src, dst;
unsigned id;
bool ret = false;
for (id = 0; id < Inode_opt_nr; id++) {
/* Skip attributes that were explicitly set on this inode */
if (dst_u->bi_fields_set & (1 << id))
continue;
src = bch2_inode_opt_get(src_u, id);
dst = bch2_inode_opt_get(dst_u, id);
if (src == dst)
continue;
bch2_inode_opt_set(dst_u, id, src);
ret = true;
}
return ret;
}
static int subvol_update_parent(struct btree_trans *trans, u32 subvol, u32 new_parent)
{
struct btree_iter iter;
struct bkey_i_subvolume *s =
bch2_bkey_get_mut_typed(trans, &iter,
BTREE_ID_subvolumes, POS(0, subvol),
BTREE_ITER_cached, subvolume);
int ret = PTR_ERR_OR_ZERO(s);
if (ret)
return ret;
s->v.fs_path_parent = cpu_to_le32(new_parent);
bch2_trans_iter_exit(trans, &iter);
return 0;
}
int bch2_rename_trans(struct btree_trans *trans,
subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
struct bch_inode_unpacked *src_inode_u,
struct bch_inode_unpacked *dst_inode_u,
const struct qstr *src_name,
const struct qstr *dst_name,
enum bch_rename_mode mode)
{
struct bch_fs *c = trans->c;
struct btree_iter src_dir_iter = { NULL };
struct btree_iter dst_dir_iter = { NULL };
struct btree_iter src_inode_iter = { NULL };
struct btree_iter dst_inode_iter = { NULL };
struct bch_hash_info src_hash, dst_hash;
subvol_inum src_inum, dst_inum;
u64 src_offset, dst_offset;
u64 now = bch2_current_time(c);
int ret;
ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
BTREE_ITER_intent);
if (ret)
goto err;
src_hash = bch2_hash_info_init(c, src_dir_u);
if (dst_dir.inum != src_dir.inum ||
dst_dir.subvol != src_dir.subvol) {
ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
BTREE_ITER_intent);
if (ret)
goto err;
dst_hash = bch2_hash_info_init(c, dst_dir_u);
} else {
dst_dir_u = src_dir_u;
dst_hash = src_hash;
}
ret = bch2_dirent_rename(trans,
src_dir, &src_hash,
dst_dir, &dst_hash,
src_name, &src_inum, &src_offset,
dst_name, &dst_inum, &dst_offset,
mode);
if (ret)
goto err;
ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
BTREE_ITER_intent);
if (ret)
goto err;
if (dst_inum.inum) {
ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
BTREE_ITER_intent);
if (ret)
goto err;
}
if (src_inode_u->bi_subvol &&
dst_dir.subvol != src_inode_u->bi_parent_subvol) {
ret = subvol_update_parent(trans, src_inode_u->bi_subvol, dst_dir.subvol);
if (ret)
goto err;
}
if (mode == BCH_RENAME_EXCHANGE &&
dst_inode_u->bi_subvol &&
src_dir.subvol != dst_inode_u->bi_parent_subvol) {
ret = subvol_update_parent(trans, dst_inode_u->bi_subvol, src_dir.subvol);
if (ret)
goto err;
}
/* Can't move across subvolumes, unless it's a subvolume root: */
if (src_dir.subvol != dst_dir.subvol &&
(!src_inode_u->bi_subvol ||
(dst_inum.inum && !dst_inode_u->bi_subvol))) {
ret = -EXDEV;
goto err;
}
if (src_inode_u->bi_parent_subvol)
src_inode_u->bi_parent_subvol = dst_dir.subvol;
if ((mode == BCH_RENAME_EXCHANGE) &&
dst_inode_u->bi_parent_subvol)
dst_inode_u->bi_parent_subvol = src_dir.subvol;
src_inode_u->bi_dir = dst_dir_u->bi_inum;
src_inode_u->bi_dir_offset = dst_offset;
if (mode == BCH_RENAME_EXCHANGE) {
dst_inode_u->bi_dir = src_dir_u->bi_inum;
dst_inode_u->bi_dir_offset = src_offset;
}
if (mode == BCH_RENAME_OVERWRITE &&
dst_inode_u->bi_dir == dst_dir_u->bi_inum &&
dst_inode_u->bi_dir_offset == src_offset) {
dst_inode_u->bi_dir = 0;
dst_inode_u->bi_dir_offset = 0;
}
if (mode == BCH_RENAME_OVERWRITE) {
if (S_ISDIR(src_inode_u->bi_mode) !=
S_ISDIR(dst_inode_u->bi_mode)) {
ret = -ENOTDIR;
goto err;
}
if (S_ISDIR(dst_inode_u->bi_mode)) {
ret = bch2_empty_dir_trans(trans, dst_inum);
if (ret)
goto err;
}
}
if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
S_ISDIR(src_inode_u->bi_mode)) {
ret = -EXDEV;
goto err;
}
if (mode == BCH_RENAME_EXCHANGE &&
bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
S_ISDIR(dst_inode_u->bi_mode)) {
ret = -EXDEV;
goto err;
}
if (is_subdir_for_nlink(src_inode_u)) {
src_dir_u->bi_nlink--;
dst_dir_u->bi_nlink++;
}
if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) {
dst_dir_u->bi_nlink--;
src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE;
}
if (mode == BCH_RENAME_OVERWRITE)
bch2_inode_nlink_dec(trans, dst_inode_u);
src_dir_u->bi_mtime = now;
src_dir_u->bi_ctime = now;
if (src_dir.inum != dst_dir.inum) {
dst_dir_u->bi_mtime = now;
dst_dir_u->bi_ctime = now;
}
src_inode_u->bi_ctime = now;
if (dst_inum.inum)
dst_inode_u->bi_ctime = now;
ret = bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?:
(src_dir.inum != dst_dir.inum
? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u)
: 0) ?:
bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?:
(dst_inum.inum
? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u)
: 0);
err:
bch2_trans_iter_exit(trans, &dst_inode_iter);
bch2_trans_iter_exit(trans, &src_inode_iter);
bch2_trans_iter_exit(trans, &dst_dir_iter);
bch2_trans_iter_exit(trans, &src_dir_iter);
return ret;
}