+++ /dev/null
-// 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)
-{
- 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_invalid(struct bch_fs *c, struct bkey_s_c k,
- enum bkey_invalid_flags flags,
- struct printbuf *err)
-{
- 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, err,
- dirent_empty_name,
- "empty name");
-
- bkey_fsck_err_on(bkey_val_u64s(k.k) > dirent_val_u64s(d_name.len), c, err,
- 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 & BKEY_INVALID_COMMIT) && d_name.len > BCH_NAME_MAX, c, err,
- 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, err,
- 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, err,
- dirent_name_dot_or_dotdot,
- "invalid name");
-
- bkey_fsck_err_on(memchr(d_name.name, '/', d_name.len), c, err,
- 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, err,
- 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 -> %llu type %s",
- d_name.len,
- d_name.name,
- d.v->d_type != DT_SUBVOL
- ? le64_to_cpu(d.v->d_inum)
- : le32_to_cpu(d.v->d_child_subvol),
- 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,
- u64 dir, u32 snapshot,
- const struct bch_hash_info *hash_info,
- u8 type, const struct qstr *name, u64 dst_inum,
- u64 *dir_offset,
- bch_str_hash_flags_t str_hash_flags)
-{
- subvol_inum zero_inum = { 0 };
- struct bkey_i_dirent *dirent;
- int ret;
-
- dirent = dirent_create_key(trans, zero_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_snapshot(trans, bch2_dirent_hash_desc, hash_info,
- zero_inum, snapshot,
- &dirent->k_i, str_hash_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,
- bch_str_hash_flags_t str_hash_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, str_hash_flags);
- *dir_offset = dirent->k.p.offset;
-
- return ret;
-}
-
-static void dirent_copy_target(struct bkey_i_dirent *dst,
- struct bkey_s_c_dirent src)
-{
- dst->v.d_inum = src.v->d_inum;
- dst->v.d_type = src.v->d_type;
-}
-
-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_type = 0, dst_type = 0, src_update_flags = 0;
- int ret = 0;
-
- if (src_dir.subvol != dst_dir.subvol)
- return -EXDEV;
-
- memset(src_inum, 0, sizeof(*src_inum));
- memset(dst_inum, 0, sizeof(*dst_inum));
-
- /* Lookup src: */
- ret = bch2_hash_lookup(trans, &src_iter, bch2_dirent_hash_desc,
- src_hash, src_dir, src_name,
- BTREE_ITER_INTENT);
- if (ret)
- goto out;
-
- old_src = bch2_btree_iter_peek_slot(&src_iter);
- 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;
-
- src_type = bkey_s_c_to_dirent(old_src).v->d_type;
-
- if (src_type == DT_SUBVOL && mode == BCH_RENAME_EXCHANGE)
- return -EOPNOTSUPP;
-
-
- /* 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 {
- ret = bch2_hash_lookup(trans, &dst_iter, bch2_dirent_hash_desc,
- dst_hash, dst_dir, dst_name,
- BTREE_ITER_INTENT);
- if (ret)
- goto out;
-
- old_dst = bch2_btree_iter_peek_slot(&dst_iter);
- 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;
-
- dst_type = bkey_s_c_to_dirent(old_dst).v->d_type;
-
- if (dst_type == DT_SUBVOL)
- return -EOPNOTSUPP;
- }
-
- 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;
- }
- }
-
- 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:
- */
- if (src_type == DT_SUBVOL) {
- bch2_btree_iter_set_snapshot(&src_iter, old_src.k->p.snapshot);
- ret = bch2_btree_iter_traverse(&src_iter);
- if (ret)
- goto out;
-
- new_src->k.p = src_iter.pos;
- src_update_flags |= BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE;
- }
-
- ret = bch2_trans_update(trans, &src_iter, &new_src->k_i, src_update_flags);
- 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;
- struct bkey_s_c_dirent d;
- u32 snapshot;
- int ret;
-
- ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot);
- if (ret)
- return ret;
-
- ret = bch2_hash_lookup(trans, iter, bch2_dirent_hash_desc,
- hash_info, dir, name, flags);
- if (ret)
- return ret;
-
- k = bch2_btree_iter_peek_slot(iter);
- ret = bkey_err(k);
- if (ret)
- goto err;
-
- d = bkey_s_c_to_dirent(k);
-
- ret = bch2_dirent_read_target(trans, dir, d, 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 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) {
- ret = -ENOTEMPTY;
- 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, snapshot);
-}
-
-int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
-{
- struct btree_trans *trans = bch2_trans_get(c);
- struct btree_iter iter;
- struct bkey_s_c k;
- struct bkey_s_c_dirent dirent;
- subvol_inum target;
- u32 snapshot;
- struct bkey_buf sk;
- struct qstr name;
- int ret;
-
- bch2_bkey_buf_init(&sk);
-retry:
- bch2_trans_begin(trans);
-
- ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
- if (ret)
- goto err;
-
- for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_dirents,
- SPOS(inum.inum, ctx->pos, snapshot),
- POS(inum.inum, U64_MAX), 0, k, ret) {
- if (k.k->type != KEY_TYPE_dirent)
- continue;
-
- dirent = bkey_s_c_to_dirent(k);
-
- ret = bch2_dirent_read_target(trans, inum, dirent, &target);
- if (ret < 0)
- break;
- if (ret)
- continue;
-
- /* dir_emit() can fault and block: */
- bch2_bkey_buf_reassemble(&sk, c, k);
- dirent = bkey_i_to_s_c_dirent(sk.k);
- bch2_trans_unlock(trans);
-
- name = bch2_dirent_get_name(dirent);
-
- ctx->pos = dirent.k->p.offset;
- if (!dir_emit(ctx, name.name,
- name.len,
- target.inum,
- vfs_d_type(dirent.v->d_type)))
- break;
- ctx->pos = dirent.k->p.offset + 1;
-
- /*
- * read_target looks up subvolumes, we can overflow paths if the
- * directory has many subvolumes in it
- */
- ret = btree_trans_too_many_iters(trans);
- if (ret)
- break;
- }
- bch2_trans_iter_exit(trans, &iter);
-err:
- if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
- goto retry;
-
- bch2_trans_put(trans);
- bch2_bkey_buf_exit(&sk, c);
-
- return ret;
-}
projects / bcachefs-tools-debian / blobdiff