diff options
Diffstat (limited to 'fs/bcachefs/dirent.c')
| -rw-r--r-- | fs/bcachefs/dirent.c | 574 |
1 files changed, 0 insertions, 574 deletions
diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c deleted file mode 100644 index faffc98d5605..000000000000 --- a/fs/bcachefs/dirent.c +++ /dev/null @@ -1,574 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -#include "bcachefs.h" -#include "bkey_buf.h" -#include "bkey_methods.h" -#include "btree_update.h" -#include "extents.h" -#include "dirent.h" -#include "fs.h" -#include "keylist.h" -#include "str_hash.h" -#include "subvolume.h" - -#include <linux/dcache.h> - -static unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d) -{ - if (bkey_val_bytes(d.k) < offsetof(struct bch_dirent, d_name)) - return 0; - - unsigned bkey_u64s = bkey_val_u64s(d.k); - unsigned bkey_bytes = bkey_u64s * sizeof(u64); - u64 last_u64 = ((u64*)d.v)[bkey_u64s - 1]; -#if CPU_BIG_ENDIAN - unsigned trailing_nuls = last_u64 ? __builtin_ctzll(last_u64) / 8 : 64 / 8; -#else - unsigned trailing_nuls = last_u64 ? __builtin_clzll(last_u64) / 8 : 64 / 8; -#endif - - return bkey_bytes - - offsetof(struct bch_dirent, d_name) - - trailing_nuls; -} - -struct qstr bch2_dirent_get_name(struct bkey_s_c_dirent d) -{ - return (struct qstr) QSTR_INIT(d.v->d_name, bch2_dirent_name_bytes(d)); -} - -static u64 bch2_dirent_hash(const struct bch_hash_info *info, - const struct qstr *name) -{ - struct bch_str_hash_ctx ctx; - - bch2_str_hash_init(&ctx, info); - bch2_str_hash_update(&ctx, info, name->name, name->len); - - /* [0,2) reserved for dots */ - return max_t(u64, bch2_str_hash_end(&ctx, info), 2); -} - -static u64 dirent_hash_key(const struct bch_hash_info *info, const void *key) -{ - return bch2_dirent_hash(info, key); -} - -static u64 dirent_hash_bkey(const struct bch_hash_info *info, struct bkey_s_c k) -{ - struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k); - struct qstr name = bch2_dirent_get_name(d); - - return bch2_dirent_hash(info, &name); -} - -static bool dirent_cmp_key(struct bkey_s_c _l, const void *_r) -{ - struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l); - const struct qstr l_name = bch2_dirent_get_name(l); - const struct qstr *r_name = _r; - - return !qstr_eq(l_name, *r_name); -} - -static bool dirent_cmp_bkey(struct bkey_s_c _l, struct bkey_s_c _r) -{ - struct bkey_s_c_dirent l = bkey_s_c_to_dirent(_l); - struct bkey_s_c_dirent r = bkey_s_c_to_dirent(_r); - const struct qstr l_name = bch2_dirent_get_name(l); - const struct qstr r_name = bch2_dirent_get_name(r); - - return !qstr_eq(l_name, r_name); -} - -static bool dirent_is_visible(subvol_inum inum, struct bkey_s_c k) -{ - struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k); - - if (d.v->d_type == DT_SUBVOL) - return le32_to_cpu(d.v->d_parent_subvol) == inum.subvol; - return true; -} - -const struct bch_hash_desc bch2_dirent_hash_desc = { - .btree_id = BTREE_ID_dirents, - .key_type = KEY_TYPE_dirent, - .hash_key = dirent_hash_key, - .hash_bkey = dirent_hash_bkey, - .cmp_key = dirent_cmp_key, - .cmp_bkey = dirent_cmp_bkey, - .is_visible = dirent_is_visible, -}; - -int bch2_dirent_validate(struct bch_fs *c, struct bkey_s_c k, - enum bch_validate_flags flags) -{ - struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k); - struct qstr d_name = bch2_dirent_get_name(d); - int ret = 0; - - bkey_fsck_err_on(!d_name.len, - c, dirent_empty_name, - "empty name"); - - bkey_fsck_err_on(bkey_val_u64s(k.k) > dirent_val_u64s(d_name.len), - c, dirent_val_too_big, - "value too big (%zu > %u)", - bkey_val_u64s(k.k), dirent_val_u64s(d_name.len)); - - /* - * Check new keys don't exceed the max length - * (older keys may be larger.) - */ - bkey_fsck_err_on((flags & BCH_VALIDATE_commit) && d_name.len > BCH_NAME_MAX, - c, dirent_name_too_long, - "dirent name too big (%u > %u)", - d_name.len, BCH_NAME_MAX); - - bkey_fsck_err_on(d_name.len != strnlen(d_name.name, d_name.len), - c, dirent_name_embedded_nul, - "dirent has stray data after name's NUL"); - - bkey_fsck_err_on((d_name.len == 1 && !memcmp(d_name.name, ".", 1)) || - (d_name.len == 2 && !memcmp(d_name.name, "..", 2)), - c, dirent_name_dot_or_dotdot, - "invalid name"); - - bkey_fsck_err_on(memchr(d_name.name, '/', d_name.len), - c, dirent_name_has_slash, - "name with /"); - - bkey_fsck_err_on(d.v->d_type != DT_SUBVOL && - le64_to_cpu(d.v->d_inum) == d.k->p.inode, - c, dirent_to_itself, - "dirent points to own directory"); -fsck_err: - return ret; -} - -void bch2_dirent_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k) -{ - struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k); - struct qstr d_name = bch2_dirent_get_name(d); - - prt_printf(out, "%.*s -> ", d_name.len, d_name.name); - - if (d.v->d_type != DT_SUBVOL) - prt_printf(out, "%llu", le64_to_cpu(d.v->d_inum)); - else - prt_printf(out, "%u -> %u", - le32_to_cpu(d.v->d_parent_subvol), - le32_to_cpu(d.v->d_child_subvol)); - - prt_printf(out, " type %s", bch2_d_type_str(d.v->d_type)); -} - -static struct bkey_i_dirent *dirent_create_key(struct btree_trans *trans, - subvol_inum dir, u8 type, - const struct qstr *name, u64 dst) -{ - struct bkey_i_dirent *dirent; - unsigned u64s = BKEY_U64s + dirent_val_u64s(name->len); - - if (name->len > BCH_NAME_MAX) - return ERR_PTR(-ENAMETOOLONG); - - BUG_ON(u64s > U8_MAX); - - dirent = bch2_trans_kmalloc(trans, u64s * sizeof(u64)); - if (IS_ERR(dirent)) - return dirent; - - bkey_dirent_init(&dirent->k_i); - dirent->k.u64s = u64s; - - if (type != DT_SUBVOL) { - dirent->v.d_inum = cpu_to_le64(dst); - } else { - dirent->v.d_parent_subvol = cpu_to_le32(dir.subvol); - dirent->v.d_child_subvol = cpu_to_le32(dst); - } - - dirent->v.d_type = type; - - memcpy(dirent->v.d_name, name->name, name->len); - memset(dirent->v.d_name + name->len, 0, - bkey_val_bytes(&dirent->k) - - offsetof(struct bch_dirent, d_name) - - name->len); - - EBUG_ON(bch2_dirent_name_bytes(dirent_i_to_s_c(dirent)) != name->len); - - return dirent; -} - -int bch2_dirent_create_snapshot(struct btree_trans *trans, - u32 dir_subvol, u64 dir, u32 snapshot, - const struct bch_hash_info *hash_info, - u8 type, const struct qstr *name, u64 dst_inum, - u64 *dir_offset, - enum btree_iter_update_trigger_flags flags) -{ - subvol_inum dir_inum = { .subvol = dir_subvol, .inum = dir }; - struct bkey_i_dirent *dirent; - int ret; - - dirent = dirent_create_key(trans, dir_inum, type, name, dst_inum); - ret = PTR_ERR_OR_ZERO(dirent); - if (ret) - return ret; - - dirent->k.p.inode = dir; - dirent->k.p.snapshot = snapshot; - - ret = bch2_hash_set_in_snapshot(trans, bch2_dirent_hash_desc, hash_info, - dir_inum, snapshot, &dirent->k_i, - flags|BTREE_UPDATE_internal_snapshot_node); - *dir_offset = dirent->k.p.offset; - - return ret; -} - -int bch2_dirent_create(struct btree_trans *trans, subvol_inum dir, - const struct bch_hash_info *hash_info, - u8 type, const struct qstr *name, u64 dst_inum, - u64 *dir_offset, - enum btree_iter_update_trigger_flags flags) -{ - struct bkey_i_dirent *dirent; - int ret; - - dirent = dirent_create_key(trans, dir, type, name, dst_inum); - ret = PTR_ERR_OR_ZERO(dirent); - if (ret) - return ret; - - ret = bch2_hash_set(trans, bch2_dirent_hash_desc, hash_info, - dir, &dirent->k_i, flags); - *dir_offset = dirent->k.p.offset; - - return ret; -} - -int bch2_dirent_read_target(struct btree_trans *trans, subvol_inum dir, - struct bkey_s_c_dirent d, subvol_inum *target) -{ - struct bch_subvolume s; - int ret = 0; - - if (d.v->d_type == DT_SUBVOL && - le32_to_cpu(d.v->d_parent_subvol) != dir.subvol) - return 1; - - if (likely(d.v->d_type != DT_SUBVOL)) { - target->subvol = dir.subvol; - target->inum = le64_to_cpu(d.v->d_inum); - } else { - target->subvol = le32_to_cpu(d.v->d_child_subvol); - - ret = bch2_subvolume_get(trans, target->subvol, true, BTREE_ITER_cached, &s); - - target->inum = le64_to_cpu(s.inode); - } - - return ret; -} - -int bch2_dirent_rename(struct btree_trans *trans, - subvol_inum src_dir, struct bch_hash_info *src_hash, - subvol_inum dst_dir, struct bch_hash_info *dst_hash, - const struct qstr *src_name, subvol_inum *src_inum, u64 *src_offset, - const struct qstr *dst_name, subvol_inum *dst_inum, u64 *dst_offset, - enum bch_rename_mode mode) -{ - struct btree_iter src_iter = { NULL }; - struct btree_iter dst_iter = { NULL }; - struct bkey_s_c old_src, old_dst = bkey_s_c_null; - struct bkey_i_dirent *new_src = NULL, *new_dst = NULL; - struct bpos dst_pos = - POS(dst_dir.inum, bch2_dirent_hash(dst_hash, dst_name)); - unsigned src_update_flags = 0; - bool delete_src, delete_dst; - int ret = 0; - - memset(src_inum, 0, sizeof(*src_inum)); - memset(dst_inum, 0, sizeof(*dst_inum)); - - /* Lookup src: */ - old_src = bch2_hash_lookup(trans, &src_iter, bch2_dirent_hash_desc, - src_hash, src_dir, src_name, - BTREE_ITER_intent); - ret = bkey_err(old_src); - if (ret) - goto out; - - ret = bch2_dirent_read_target(trans, src_dir, - bkey_s_c_to_dirent(old_src), src_inum); - if (ret) - goto out; - - /* Lookup dst: */ - if (mode == BCH_RENAME) { - /* - * Note that we're _not_ checking if the target already exists - - * we're relying on the VFS to do that check for us for - * correctness: - */ - ret = bch2_hash_hole(trans, &dst_iter, bch2_dirent_hash_desc, - dst_hash, dst_dir, dst_name); - if (ret) - goto out; - } else { - old_dst = bch2_hash_lookup(trans, &dst_iter, bch2_dirent_hash_desc, - dst_hash, dst_dir, dst_name, - BTREE_ITER_intent); - ret = bkey_err(old_dst); - if (ret) - goto out; - - ret = bch2_dirent_read_target(trans, dst_dir, - bkey_s_c_to_dirent(old_dst), dst_inum); - if (ret) - goto out; - } - - if (mode != BCH_RENAME_EXCHANGE) - *src_offset = dst_iter.pos.offset; - - /* Create new dst key: */ - new_dst = dirent_create_key(trans, dst_dir, 0, dst_name, 0); - ret = PTR_ERR_OR_ZERO(new_dst); - if (ret) - goto out; - - dirent_copy_target(new_dst, bkey_s_c_to_dirent(old_src)); - new_dst->k.p = dst_iter.pos; - - /* Create new src key: */ - if (mode == BCH_RENAME_EXCHANGE) { - new_src = dirent_create_key(trans, src_dir, 0, src_name, 0); - ret = PTR_ERR_OR_ZERO(new_src); - if (ret) - goto out; - - dirent_copy_target(new_src, bkey_s_c_to_dirent(old_dst)); - new_src->k.p = src_iter.pos; - } else { - new_src = bch2_trans_kmalloc(trans, sizeof(struct bkey_i)); - ret = PTR_ERR_OR_ZERO(new_src); - if (ret) - goto out; - - bkey_init(&new_src->k); - new_src->k.p = src_iter.pos; - - if (bkey_le(dst_pos, src_iter.pos) && - bkey_lt(src_iter.pos, dst_iter.pos)) { - /* - * We have a hash collision for the new dst key, - * and new_src - the key we're deleting - is between - * new_dst's hashed slot and the slot we're going to be - * inserting it into - oops. This will break the hash - * table if we don't deal with it: - */ - if (mode == BCH_RENAME) { - /* - * If we're not overwriting, we can just insert - * new_dst at the src position: - */ - new_src = new_dst; - new_src->k.p = src_iter.pos; - goto out_set_src; - } else { - /* If we're overwriting, we can't insert new_dst - * at a different slot because it has to - * overwrite old_dst - just make sure to use a - * whiteout when deleting src: - */ - new_src->k.type = KEY_TYPE_hash_whiteout; - } - } else { - /* Check if we need a whiteout to delete src: */ - ret = bch2_hash_needs_whiteout(trans, bch2_dirent_hash_desc, - src_hash, &src_iter); - if (ret < 0) - goto out; - - if (ret) - new_src->k.type = KEY_TYPE_hash_whiteout; - } - } - - if (new_dst->v.d_type == DT_SUBVOL) - new_dst->v.d_parent_subvol = cpu_to_le32(dst_dir.subvol); - - if ((mode == BCH_RENAME_EXCHANGE) && - new_src->v.d_type == DT_SUBVOL) - new_src->v.d_parent_subvol = cpu_to_le32(src_dir.subvol); - - ret = bch2_trans_update(trans, &dst_iter, &new_dst->k_i, 0); - if (ret) - goto out; -out_set_src: - /* - * If we're deleting a subvolume we need to really delete the dirent, - * not just emit a whiteout in the current snapshot - there can only be - * single dirent that points to a given subvolume. - * - * IOW, we don't maintain multiple versions in different snapshots of - * dirents that point to subvolumes - dirents that point to subvolumes - * are only visible in one particular subvolume so it's not necessary, - * and it would be particularly confusing for fsck to have to deal with. - */ - delete_src = bkey_s_c_to_dirent(old_src).v->d_type == DT_SUBVOL && - new_src->k.p.snapshot != old_src.k->p.snapshot; - - delete_dst = old_dst.k && - bkey_s_c_to_dirent(old_dst).v->d_type == DT_SUBVOL && - new_dst->k.p.snapshot != old_dst.k->p.snapshot; - - if (!delete_src || !bkey_deleted(&new_src->k)) { - ret = bch2_trans_update(trans, &src_iter, &new_src->k_i, src_update_flags); - if (ret) - goto out; - } - - if (delete_src) { - bch2_btree_iter_set_snapshot(&src_iter, old_src.k->p.snapshot); - ret = bch2_btree_iter_traverse(&src_iter) ?: - bch2_btree_delete_at(trans, &src_iter, BTREE_UPDATE_internal_snapshot_node); - if (ret) - goto out; - } - - if (delete_dst) { - bch2_btree_iter_set_snapshot(&dst_iter, old_dst.k->p.snapshot); - ret = bch2_btree_iter_traverse(&dst_iter) ?: - bch2_btree_delete_at(trans, &dst_iter, BTREE_UPDATE_internal_snapshot_node); - if (ret) - goto out; - } - - if (mode == BCH_RENAME_EXCHANGE) - *src_offset = new_src->k.p.offset; - *dst_offset = new_dst->k.p.offset; -out: - bch2_trans_iter_exit(trans, &src_iter); - bch2_trans_iter_exit(trans, &dst_iter); - return ret; -} - -int bch2_dirent_lookup_trans(struct btree_trans *trans, - struct btree_iter *iter, - subvol_inum dir, - const struct bch_hash_info *hash_info, - const struct qstr *name, subvol_inum *inum, - unsigned flags) -{ - struct bkey_s_c k = bch2_hash_lookup(trans, iter, bch2_dirent_hash_desc, - hash_info, dir, name, flags); - int ret = bkey_err(k); - if (ret) - goto err; - - ret = bch2_dirent_read_target(trans, dir, bkey_s_c_to_dirent(k), inum); - if (ret > 0) - ret = -ENOENT; -err: - if (ret) - bch2_trans_iter_exit(trans, iter); - return ret; -} - -u64 bch2_dirent_lookup(struct bch_fs *c, subvol_inum dir, - const struct bch_hash_info *hash_info, - const struct qstr *name, subvol_inum *inum) -{ - struct btree_trans *trans = bch2_trans_get(c); - struct btree_iter iter = { NULL }; - - int ret = lockrestart_do(trans, - bch2_dirent_lookup_trans(trans, &iter, dir, hash_info, name, inum, 0)); - bch2_trans_iter_exit(trans, &iter); - bch2_trans_put(trans); - return ret; -} - -int bch2_empty_dir_snapshot(struct btree_trans *trans, u64 dir, u32 subvol, u32 snapshot) -{ - struct btree_iter iter; - struct bkey_s_c k; - int ret; - - for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_dirents, - SPOS(dir, 0, snapshot), - POS(dir, U64_MAX), 0, k, ret) - if (k.k->type == KEY_TYPE_dirent) { - struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k); - if (d.v->d_type == DT_SUBVOL && le32_to_cpu(d.v->d_parent_subvol) != subvol) - continue; - ret = -BCH_ERR_ENOTEMPTY_dir_not_empty; - break; - } - bch2_trans_iter_exit(trans, &iter); - - return ret; -} - -int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir) -{ - u32 snapshot; - - return bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot) ?: - bch2_empty_dir_snapshot(trans, dir.inum, dir.subvol, snapshot); -} - -static int bch2_dir_emit(struct dir_context *ctx, struct bkey_s_c_dirent d, subvol_inum target) -{ - struct qstr name = bch2_dirent_get_name(d); - /* - * Although not required by the kernel code, updating ctx->pos is needed - * for the bcachefs FUSE driver. Without this update, the FUSE - * implementation will be stuck in an infinite loop when reading - * directories (via the bcachefs_fuse_readdir callback). - * In kernel space, ctx->pos is updated by the VFS code. - */ - ctx->pos = d.k->p.offset; - bool ret = dir_emit(ctx, name.name, - name.len, - target.inum, - vfs_d_type(d.v->d_type)); - if (ret) - ctx->pos = d.k->p.offset + 1; - return ret; -} - -int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx) -{ - struct bkey_buf sk; - bch2_bkey_buf_init(&sk); - - int ret = bch2_trans_run(c, - for_each_btree_key_in_subvolume_upto(trans, iter, BTREE_ID_dirents, - POS(inum.inum, ctx->pos), - POS(inum.inum, U64_MAX), - inum.subvol, 0, k, ({ - if (k.k->type != KEY_TYPE_dirent) - continue; - - /* dir_emit() can fault and block: */ - bch2_bkey_buf_reassemble(&sk, c, k); - struct bkey_s_c_dirent dirent = bkey_i_to_s_c_dirent(sk.k); - - subvol_inum target; - int ret2 = bch2_dirent_read_target(trans, inum, dirent, &target); - if (ret2 > 0) - continue; - - ret2 ?: drop_locks_do(trans, bch2_dir_emit(ctx, dirent, target)); - }))); - - bch2_bkey_buf_exit(&sk, c); - - return ret < 0 ? ret : 0; -} |
