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// SPDX-License-Identifier: GPL-2.0
/*
* io_misc.c - fallocate, fpunch, truncate:
*/
#include "bcachefs.h"
#include "alloc_foreground.h"
#include "bkey_buf.h"
#include "btree_update.h"
#include "buckets.h"
#include "clock.h"
#include "extents.h"
#include "io_misc.h"
#include "io_write.h"
#include "subvolume.h"
/* Overwrites whatever was present with zeroes: */
int bch2_extent_fallocate(struct btree_trans *trans,
subvol_inum inum,
struct btree_iter *iter,
unsigned sectors,
struct bch_io_opts opts,
s64 *i_sectors_delta,
struct write_point_specifier write_point)
{
struct bch_fs *c = trans->c;
struct disk_reservation disk_res = { 0 };
struct closure cl;
struct open_buckets open_buckets = { 0 };
struct bkey_s_c k;
struct bkey_buf old, new;
unsigned sectors_allocated = 0;
bool have_reservation = false;
bool unwritten = opts.nocow &&
c->sb.version >= bcachefs_metadata_version_unwritten_extents;
int ret;
bch2_bkey_buf_init(&old);
bch2_bkey_buf_init(&new);
closure_init_stack(&cl);
k = bch2_btree_iter_peek_slot(iter);
ret = bkey_err(k);
if (ret)
return ret;
sectors = min_t(u64, sectors, k.k->p.offset - iter->pos.offset);
if (!have_reservation) {
unsigned new_replicas =
max(0, (int) opts.data_replicas -
(int) bch2_bkey_nr_ptrs_fully_allocated(k));
/*
* Get a disk reservation before (in the nocow case) calling
* into the allocator:
*/
ret = bch2_disk_reservation_get(c, &disk_res, sectors, new_replicas, 0);
if (unlikely(ret))
goto err;
bch2_bkey_buf_reassemble(&old, c, k);
}
if (have_reservation) {
if (!bch2_extents_match(k, bkey_i_to_s_c(old.k)))
goto err;
bch2_key_resize(&new.k->k, sectors);
} else if (!unwritten) {
struct bkey_i_reservation *reservation;
bch2_bkey_buf_realloc(&new, c, sizeof(*reservation) / sizeof(u64));
reservation = bkey_reservation_init(new.k);
reservation->k.p = iter->pos;
bch2_key_resize(&reservation->k, sectors);
reservation->v.nr_replicas = opts.data_replicas;
} else {
struct bkey_i_extent *e;
struct bch_devs_list devs_have;
struct write_point *wp;
struct bch_extent_ptr *ptr;
devs_have.nr = 0;
bch2_bkey_buf_realloc(&new, c, BKEY_EXTENT_U64s_MAX);
e = bkey_extent_init(new.k);
e->k.p = iter->pos;
ret = bch2_alloc_sectors_start_trans(trans,
opts.foreground_target,
false,
write_point,
&devs_have,
opts.data_replicas,
opts.data_replicas,
BCH_WATERMARK_normal, 0, &cl, &wp);
if (bch2_err_matches(ret, BCH_ERR_operation_blocked))
ret = -BCH_ERR_transaction_restart_nested;
if (ret)
goto err;
sectors = min(sectors, wp->sectors_free);
sectors_allocated = sectors;
bch2_key_resize(&e->k, sectors);
bch2_open_bucket_get(c, wp, &open_buckets);
bch2_alloc_sectors_append_ptrs(c, wp, &e->k_i, sectors, false);
bch2_alloc_sectors_done(c, wp);
extent_for_each_ptr(extent_i_to_s(e), ptr)
ptr->unwritten = true;
}
have_reservation = true;
ret = bch2_extent_update(trans, inum, iter, new.k, &disk_res,
0, i_sectors_delta, true);
err:
if (!ret && sectors_allocated)
bch2_increment_clock(c, sectors_allocated, WRITE);
bch2_open_buckets_put(c, &open_buckets);
bch2_disk_reservation_put(c, &disk_res);
bch2_bkey_buf_exit(&new, c);
bch2_bkey_buf_exit(&old, c);
if (closure_nr_remaining(&cl) != 1) {
bch2_trans_unlock(trans);
closure_sync(&cl);
}
return ret;
}
/*
* Returns -BCH_ERR_transacton_restart if we had to drop locks:
*/
int bch2_fpunch_at(struct btree_trans *trans, struct btree_iter *iter,
subvol_inum inum, u64 end,
s64 *i_sectors_delta)
{
struct bch_fs *c = trans->c;
unsigned max_sectors = KEY_SIZE_MAX & (~0 << c->block_bits);
struct bpos end_pos = POS(inum.inum, end);
struct bkey_s_c k;
int ret = 0, ret2 = 0;
u32 snapshot;
while (!ret ||
bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
struct disk_reservation disk_res =
bch2_disk_reservation_init(c, 0);
struct bkey_i delete;
if (ret)
ret2 = ret;
bch2_trans_begin(trans);
ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
if (ret)
continue;
bch2_btree_iter_set_snapshot(iter, snapshot);
/*
* peek_upto() doesn't have ideal semantics for extents:
*/
k = bch2_btree_iter_peek_upto(iter, end_pos);
if (!k.k)
break;
ret = bkey_err(k);
if (ret)
continue;
bkey_init(&delete.k);
delete.k.p = iter->pos;
/* create the biggest key we can */
bch2_key_resize(&delete.k, max_sectors);
bch2_cut_back(end_pos, &delete);
ret = bch2_extent_update(trans, inum, iter, &delete,
&disk_res, 0, i_sectors_delta, false);
bch2_disk_reservation_put(c, &disk_res);
}
return ret ?: ret2;
}
int bch2_fpunch(struct bch_fs *c, subvol_inum inum, u64 start, u64 end,
s64 *i_sectors_delta)
{
struct btree_trans trans;
struct btree_iter iter;
int ret;
bch2_trans_init(&trans, c, BTREE_ITER_MAX, 1024);
bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
POS(inum.inum, start),
BTREE_ITER_INTENT);
ret = bch2_fpunch_at(&trans, &iter, inum, end, i_sectors_delta);
bch2_trans_iter_exit(&trans, &iter);
bch2_trans_exit(&trans);
if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
ret = 0;
return ret;
}
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