linux/fs/bcachefs/dirent.h
Kent Overstreet ab2a29ccff bcachefs: Inode backpointers
This patch adds two new inode fields, bi_dir and bi_dir_offset, that
point back to the inode's dirent.

Since we're only adding fields for a single backpointer, files that have
been hardlinked won't necessarily have valid backpointers: we also add a
new inode flag, BCH_INODE_BACKPTR_UNTRUSTED, that's set if an inode has
ever had multiple links to it. That's ok, because we only really need
this functionality for directories, which can never have multiple
hardlinks - when we add subvolumes, we'll need a way to enemurate and
print subvolumes, and this will let us reconstruct a path to a subvolume
root given a subvolume root inode.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:58 -04:00

64 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_DIRENT_H
#define _BCACHEFS_DIRENT_H
#include "str_hash.h"
extern const struct bch_hash_desc bch2_dirent_hash_desc;
const char *bch2_dirent_invalid(const struct bch_fs *, struct bkey_s_c);
void bch2_dirent_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
#define bch2_bkey_ops_dirent (struct bkey_ops) { \
.key_invalid = bch2_dirent_invalid, \
.val_to_text = bch2_dirent_to_text, \
}
struct qstr;
struct file;
struct dir_context;
struct bch_fs;
struct bch_hash_info;
struct bch_inode_info;
unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent);
static inline unsigned dirent_val_u64s(unsigned len)
{
return DIV_ROUND_UP(offsetof(struct bch_dirent, d_name) + len,
sizeof(u64));
}
int bch2_dirent_create(struct btree_trans *, u64,
const struct bch_hash_info *, u8,
const struct qstr *, u64, u64 *, int);
int bch2_dirent_delete_at(struct btree_trans *,
const struct bch_hash_info *,
struct btree_iter *);
enum bch_rename_mode {
BCH_RENAME,
BCH_RENAME_OVERWRITE,
BCH_RENAME_EXCHANGE,
};
int bch2_dirent_rename(struct btree_trans *,
u64, struct bch_hash_info *,
u64, struct bch_hash_info *,
const struct qstr *, u64 *, u64 *,
const struct qstr *, u64 *, u64 *,
enum bch_rename_mode);
struct btree_iter *
__bch2_dirent_lookup_trans(struct btree_trans *, u64,
const struct bch_hash_info *,
const struct qstr *, unsigned);
u64 bch2_dirent_lookup(struct bch_fs *, u64, const struct bch_hash_info *,
const struct qstr *);
int bch2_empty_dir_trans(struct btree_trans *, u64);
int bch2_readdir(struct bch_fs *, u64, struct dir_context *);
#endif /* _BCACHEFS_DIRENT_H */