linux/fs/bcachefs/btree_node_scan.c
Kent Overstreet 1c8cc24eef bcachefs: Fix incorrect error handling found_btree_node_is_readable()
error handling here is slightly odd, which is why we were accidently
calling evict() on an error pointer

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-06-10 13:17:15 -04:00

526 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "btree_cache.h"
#include "btree_io.h"
#include "btree_journal_iter.h"
#include "btree_node_scan.h"
#include "btree_update_interior.h"
#include "buckets.h"
#include "error.h"
#include "journal_io.h"
#include "recovery_passes.h"
#include <linux/kthread.h>
#include <linux/sort.h>
struct find_btree_nodes_worker {
struct closure *cl;
struct find_btree_nodes *f;
struct bch_dev *ca;
};
static void found_btree_node_to_text(struct printbuf *out, struct bch_fs *c, const struct found_btree_node *n)
{
prt_printf(out, "%s l=%u seq=%u cookie=%llx ", bch2_btree_id_str(n->btree_id), n->level, n->seq, n->cookie);
bch2_bpos_to_text(out, n->min_key);
prt_str(out, "-");
bch2_bpos_to_text(out, n->max_key);
if (n->range_updated)
prt_str(out, " range updated");
if (n->overwritten)
prt_str(out, " overwritten");
for (unsigned i = 0; i < n->nr_ptrs; i++) {
prt_char(out, ' ');
bch2_extent_ptr_to_text(out, c, n->ptrs + i);
}
}
static void found_btree_nodes_to_text(struct printbuf *out, struct bch_fs *c, found_btree_nodes nodes)
{
printbuf_indent_add(out, 2);
darray_for_each(nodes, i) {
found_btree_node_to_text(out, c, i);
prt_newline(out);
}
printbuf_indent_sub(out, 2);
}
static void found_btree_node_to_key(struct bkey_i *k, const struct found_btree_node *f)
{
struct bkey_i_btree_ptr_v2 *bp = bkey_btree_ptr_v2_init(k);
set_bkey_val_u64s(&bp->k, sizeof(struct bch_btree_ptr_v2) / sizeof(u64) + f->nr_ptrs);
bp->k.p = f->max_key;
bp->v.seq = cpu_to_le64(f->cookie);
bp->v.sectors_written = 0;
bp->v.flags = 0;
bp->v.sectors_written = cpu_to_le16(f->sectors_written);
bp->v.min_key = f->min_key;
SET_BTREE_PTR_RANGE_UPDATED(&bp->v, f->range_updated);
memcpy(bp->v.start, f->ptrs, sizeof(struct bch_extent_ptr) * f->nr_ptrs);
}
static bool found_btree_node_is_readable(struct btree_trans *trans,
struct found_btree_node *f)
{
struct { __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX); } k;
found_btree_node_to_key(&k.k, f);
struct btree *b = bch2_btree_node_get_noiter(trans, &k.k, f->btree_id, f->level, false);
bool ret = !IS_ERR_OR_NULL(b);
if (!ret)
return ret;
f->sectors_written = b->written;
six_unlock_read(&b->c.lock);
/*
* We might update this node's range; if that happens, we need the node
* to be re-read so the read path can trim keys that are no longer in
* this node
*/
if (b != btree_node_root(trans->c, b))
bch2_btree_node_evict(trans, &k.k);
return ret;
}
static int found_btree_node_cmp_cookie(const void *_l, const void *_r)
{
const struct found_btree_node *l = _l;
const struct found_btree_node *r = _r;
return cmp_int(l->btree_id, r->btree_id) ?:
cmp_int(l->level, r->level) ?:
cmp_int(l->cookie, r->cookie);
}
/*
* Given two found btree nodes, if their sequence numbers are equal, take the
* one that's readable:
*/
static int found_btree_node_cmp_time(const struct found_btree_node *l,
const struct found_btree_node *r)
{
return cmp_int(l->seq, r->seq);
}
static int found_btree_node_cmp_pos(const void *_l, const void *_r)
{
const struct found_btree_node *l = _l;
const struct found_btree_node *r = _r;
return cmp_int(l->btree_id, r->btree_id) ?:
-cmp_int(l->level, r->level) ?:
bpos_cmp(l->min_key, r->min_key) ?:
-found_btree_node_cmp_time(l, r);
}
static void try_read_btree_node(struct find_btree_nodes *f, struct bch_dev *ca,
struct bio *bio, struct btree_node *bn, u64 offset)
{
struct bch_fs *c = container_of(f, struct bch_fs, found_btree_nodes);
bio_reset(bio, ca->disk_sb.bdev, REQ_OP_READ);
bio->bi_iter.bi_sector = offset;
bch2_bio_map(bio, bn, PAGE_SIZE);
submit_bio_wait(bio);
if (bch2_dev_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_read,
"IO error in try_read_btree_node() at %llu: %s",
offset, bch2_blk_status_to_str(bio->bi_status)))
return;
if (le64_to_cpu(bn->magic) != bset_magic(c))
return;
if (bch2_csum_type_is_encryption(BSET_CSUM_TYPE(&bn->keys))) {
struct nonce nonce = btree_nonce(&bn->keys, 0);
unsigned bytes = (void *) &bn->keys - (void *) &bn->flags;
bch2_encrypt(c, BSET_CSUM_TYPE(&bn->keys), nonce, &bn->flags, bytes);
}
if (btree_id_is_alloc(BTREE_NODE_ID(bn)))
return;
if (BTREE_NODE_LEVEL(bn) >= BTREE_MAX_DEPTH)
return;
rcu_read_lock();
struct found_btree_node n = {
.btree_id = BTREE_NODE_ID(bn),
.level = BTREE_NODE_LEVEL(bn),
.seq = BTREE_NODE_SEQ(bn),
.cookie = le64_to_cpu(bn->keys.seq),
.min_key = bn->min_key,
.max_key = bn->max_key,
.nr_ptrs = 1,
.ptrs[0].type = 1 << BCH_EXTENT_ENTRY_ptr,
.ptrs[0].offset = offset,
.ptrs[0].dev = ca->dev_idx,
.ptrs[0].gen = *bucket_gen(ca, sector_to_bucket(ca, offset)),
};
rcu_read_unlock();
if (bch2_trans_run(c, found_btree_node_is_readable(trans, &n))) {
mutex_lock(&f->lock);
if (BSET_BIG_ENDIAN(&bn->keys) != CPU_BIG_ENDIAN) {
bch_err(c, "try_read_btree_node() can't handle endian conversion");
f->ret = -EINVAL;
goto unlock;
}
if (darray_push(&f->nodes, n))
f->ret = -ENOMEM;
unlock:
mutex_unlock(&f->lock);
}
}
static int read_btree_nodes_worker(void *p)
{
struct find_btree_nodes_worker *w = p;
struct bch_fs *c = container_of(w->f, struct bch_fs, found_btree_nodes);
struct bch_dev *ca = w->ca;
void *buf = (void *) __get_free_page(GFP_KERNEL);
struct bio *bio = bio_alloc(NULL, 1, 0, GFP_KERNEL);
unsigned long last_print = jiffies;
if (!buf || !bio) {
bch_err(c, "read_btree_nodes_worker: error allocating bio/buf");
w->f->ret = -ENOMEM;
goto err;
}
for (u64 bucket = ca->mi.first_bucket; bucket < ca->mi.nbuckets; bucket++)
for (unsigned bucket_offset = 0;
bucket_offset + btree_sectors(c) <= ca->mi.bucket_size;
bucket_offset += btree_sectors(c)) {
if (time_after(jiffies, last_print + HZ * 30)) {
u64 cur_sector = bucket * ca->mi.bucket_size + bucket_offset;
u64 end_sector = ca->mi.nbuckets * ca->mi.bucket_size;
bch_info(ca, "%s: %2u%% done", __func__,
(unsigned) div64_u64(cur_sector * 100, end_sector));
last_print = jiffies;
}
u64 sector = bucket * ca->mi.bucket_size + bucket_offset;
if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_mi_btree_bitmap &&
!bch2_dev_btree_bitmap_marked_sectors(ca, sector, btree_sectors(c)))
continue;
try_read_btree_node(w->f, ca, bio, buf, sector);
}
err:
bio_put(bio);
free_page((unsigned long) buf);
percpu_ref_get(&ca->io_ref);
closure_put(w->cl);
kfree(w);
return 0;
}
static int read_btree_nodes(struct find_btree_nodes *f)
{
struct bch_fs *c = container_of(f, struct bch_fs, found_btree_nodes);
struct closure cl;
int ret = 0;
closure_init_stack(&cl);
for_each_online_member(c, ca) {
if (!(ca->mi.data_allowed & BIT(BCH_DATA_btree)))
continue;
struct find_btree_nodes_worker *w = kmalloc(sizeof(*w), GFP_KERNEL);
struct task_struct *t;
if (!w) {
percpu_ref_put(&ca->io_ref);
ret = -ENOMEM;
goto err;
}
percpu_ref_get(&ca->io_ref);
closure_get(&cl);
w->cl = &cl;
w->f = f;
w->ca = ca;
t = kthread_run(read_btree_nodes_worker, w, "read_btree_nodes/%s", ca->name);
ret = IS_ERR_OR_NULL(t);
if (ret) {
percpu_ref_put(&ca->io_ref);
closure_put(&cl);
f->ret = ret;
bch_err(c, "error starting kthread: %i", ret);
break;
}
}
err:
closure_sync(&cl);
return f->ret ?: ret;
}
static void bubble_up(struct found_btree_node *n, struct found_btree_node *end)
{
while (n + 1 < end &&
found_btree_node_cmp_pos(n, n + 1) > 0) {
swap(n[0], n[1]);
n++;
}
}
static int handle_overwrites(struct bch_fs *c,
struct found_btree_node *start,
struct found_btree_node *end)
{
struct found_btree_node *n;
again:
for (n = start + 1;
n < end &&
n->btree_id == start->btree_id &&
n->level == start->level &&
bpos_lt(n->min_key, start->max_key);
n++) {
int cmp = found_btree_node_cmp_time(start, n);
if (cmp > 0) {
if (bpos_cmp(start->max_key, n->max_key) >= 0)
n->overwritten = true;
else {
n->range_updated = true;
n->min_key = bpos_successor(start->max_key);
n->range_updated = true;
bubble_up(n, end);
goto again;
}
} else if (cmp < 0) {
BUG_ON(bpos_cmp(n->min_key, start->min_key) <= 0);
start->max_key = bpos_predecessor(n->min_key);
start->range_updated = true;
} else if (n->level) {
n->overwritten = true;
} else {
struct printbuf buf = PRINTBUF;
prt_str(&buf, "overlapping btree nodes with same seq! halting\n ");
found_btree_node_to_text(&buf, c, start);
prt_str(&buf, "\n ");
found_btree_node_to_text(&buf, c, n);
bch_err(c, "%s", buf.buf);
printbuf_exit(&buf);
return -BCH_ERR_fsck_repair_unimplemented;
}
}
return 0;
}
int bch2_scan_for_btree_nodes(struct bch_fs *c)
{
struct find_btree_nodes *f = &c->found_btree_nodes;
struct printbuf buf = PRINTBUF;
size_t dst;
int ret = 0;
if (f->nodes.nr)
return 0;
mutex_init(&f->lock);
ret = read_btree_nodes(f);
if (ret)
return ret;
if (!f->nodes.nr) {
bch_err(c, "%s: no btree nodes found", __func__);
ret = -EINVAL;
goto err;
}
if (0 && c->opts.verbose) {
printbuf_reset(&buf);
prt_printf(&buf, "%s: nodes found:\n", __func__);
found_btree_nodes_to_text(&buf, c, f->nodes);
bch2_print_string_as_lines(KERN_INFO, buf.buf);
}
sort(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_cookie, NULL);
dst = 0;
darray_for_each(f->nodes, i) {
struct found_btree_node *prev = dst ? f->nodes.data + dst - 1 : NULL;
if (prev &&
prev->cookie == i->cookie) {
if (prev->nr_ptrs == ARRAY_SIZE(prev->ptrs)) {
bch_err(c, "%s: found too many replicas for btree node", __func__);
ret = -EINVAL;
goto err;
}
prev->ptrs[prev->nr_ptrs++] = i->ptrs[0];
} else {
f->nodes.data[dst++] = *i;
}
}
f->nodes.nr = dst;
sort(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_pos, NULL);
if (0 && c->opts.verbose) {
printbuf_reset(&buf);
prt_printf(&buf, "%s: nodes after merging replicas:\n", __func__);
found_btree_nodes_to_text(&buf, c, f->nodes);
bch2_print_string_as_lines(KERN_INFO, buf.buf);
}
dst = 0;
darray_for_each(f->nodes, i) {
if (i->overwritten)
continue;
ret = handle_overwrites(c, i, &darray_top(f->nodes));
if (ret)
goto err;
BUG_ON(i->overwritten);
f->nodes.data[dst++] = *i;
}
f->nodes.nr = dst;
if (c->opts.verbose) {
printbuf_reset(&buf);
prt_printf(&buf, "%s: nodes found after overwrites:\n", __func__);
found_btree_nodes_to_text(&buf, c, f->nodes);
bch2_print_string_as_lines(KERN_INFO, buf.buf);
}
eytzinger0_sort(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_pos, NULL);
err:
printbuf_exit(&buf);
return ret;
}
static int found_btree_node_range_start_cmp(const void *_l, const void *_r)
{
const struct found_btree_node *l = _l;
const struct found_btree_node *r = _r;
return cmp_int(l->btree_id, r->btree_id) ?:
-cmp_int(l->level, r->level) ?:
bpos_cmp(l->max_key, r->min_key);
}
#define for_each_found_btree_node_in_range(_f, _search, _idx) \
for (size_t _idx = eytzinger0_find_gt((_f)->nodes.data, (_f)->nodes.nr, \
sizeof((_f)->nodes.data[0]), \
found_btree_node_range_start_cmp, &search); \
_idx < (_f)->nodes.nr && \
(_f)->nodes.data[_idx].btree_id == _search.btree_id && \
(_f)->nodes.data[_idx].level == _search.level && \
bpos_lt((_f)->nodes.data[_idx].min_key, _search.max_key); \
_idx = eytzinger0_next(_idx, (_f)->nodes.nr))
bool bch2_btree_node_is_stale(struct bch_fs *c, struct btree *b)
{
struct find_btree_nodes *f = &c->found_btree_nodes;
struct found_btree_node search = {
.btree_id = b->c.btree_id,
.level = b->c.level,
.min_key = b->data->min_key,
.max_key = b->key.k.p,
};
for_each_found_btree_node_in_range(f, search, idx)
if (f->nodes.data[idx].seq > BTREE_NODE_SEQ(b->data))
return true;
return false;
}
bool bch2_btree_has_scanned_nodes(struct bch_fs *c, enum btree_id btree)
{
struct found_btree_node search = {
.btree_id = btree,
.level = 0,
.min_key = POS_MIN,
.max_key = SPOS_MAX,
};
for_each_found_btree_node_in_range(&c->found_btree_nodes, search, idx)
return true;
return false;
}
int bch2_get_scanned_nodes(struct bch_fs *c, enum btree_id btree,
unsigned level, struct bpos node_min, struct bpos node_max)
{
if (btree_id_is_alloc(btree))
return 0;
struct find_btree_nodes *f = &c->found_btree_nodes;
int ret = bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_scan_for_btree_nodes);
if (ret)
return ret;
if (c->opts.verbose) {
struct printbuf buf = PRINTBUF;
prt_printf(&buf, "recovering %s l=%u ", bch2_btree_id_str(btree), level);
bch2_bpos_to_text(&buf, node_min);
prt_str(&buf, " - ");
bch2_bpos_to_text(&buf, node_max);
bch_info(c, "%s(): %s", __func__, buf.buf);
printbuf_exit(&buf);
}
struct found_btree_node search = {
.btree_id = btree,
.level = level,
.min_key = node_min,
.max_key = node_max,
};
for_each_found_btree_node_in_range(f, search, idx) {
struct found_btree_node n = f->nodes.data[idx];
n.range_updated |= bpos_lt(n.min_key, node_min);
n.min_key = bpos_max(n.min_key, node_min);
n.range_updated |= bpos_gt(n.max_key, node_max);
n.max_key = bpos_min(n.max_key, node_max);
struct { __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX); } tmp;
found_btree_node_to_key(&tmp.k, &n);
struct printbuf buf = PRINTBUF;
bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&tmp.k));
bch_verbose(c, "%s(): recovering %s", __func__, buf.buf);
printbuf_exit(&buf);
BUG_ON(bch2_bkey_invalid(c, bkey_i_to_s_c(&tmp.k), BKEY_TYPE_btree, 0, NULL));
ret = bch2_journal_key_insert(c, btree, level + 1, &tmp.k);
if (ret)
return ret;
}
return 0;
}
void bch2_find_btree_nodes_exit(struct find_btree_nodes *f)
{
darray_exit(&f->nodes);
}