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linux/fs/bcachefs/io_read.c
Erick Archer 3e48999816 bcachefs: Prefer struct_size over open coded arithmetic 
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].

As the "op" variable is a pointer to "struct promote_op" and this
structure ends in a flexible array:

struct promote_op {
	[...]
	struct bio_vec bi_inline_vecs[];
};

and the "t" variable is a pointer to "struct journal_seq_blacklist_table"
and this structure also ends in a flexible array:

struct journal_seq_blacklist_table {
	[...]
	struct journal_seq_blacklist_table_entry {
		u64		start;
		u64		end;
		bool		dirty;
	}			entries[];
};

the preferred way in the kernel is to use the struct_size() helper to
do the arithmetic instead of the argument "size + size * count" in the
kzalloc() functions.

This way, the code is more readable and safer.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/160 [2]
Signed-off-by: Erick Archer <erick.archer@gmx.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-03-13 21:22:26 -04:00

1221 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* Some low level IO code, and hacks for various block layer limitations
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include "bcachefs.h"
#include "alloc_background.h"
#include "alloc_foreground.h"
#include "btree_update.h"
#include "buckets.h"
#include "checksum.h"
#include "clock.h"
#include "compress.h"
#include "data_update.h"
#include "disk_groups.h"
#include "ec.h"
#include "error.h"
#include "io_read.h"
#include "io_misc.h"
#include "io_write.h"
#include "subvolume.h"
#include "trace.h"
#include <linux/sched/mm.h>
#ifndef CONFIG_BCACHEFS_NO_LATENCY_ACCT
static bool bch2_target_congested(struct bch_fs *c, u16 target)
{
const struct bch_devs_mask *devs;
unsigned d, nr = 0, total = 0;
u64 now = local_clock(), last;
s64 congested;
struct bch_dev *ca;
if (!target)
return false;
rcu_read_lock();
devs = bch2_target_to_mask(c, target) ?:
&c->rw_devs[BCH_DATA_user];
for_each_set_bit(d, devs->d, BCH_SB_MEMBERS_MAX) {
ca = rcu_dereference(c->devs[d]);
if (!ca)
continue;
congested = atomic_read(&ca->congested);
last = READ_ONCE(ca->congested_last);
if (time_after64(now, last))
congested -= (now - last) >> 12;
total += max(congested, 0LL);
nr++;
}
rcu_read_unlock();
return bch2_rand_range(nr * CONGESTED_MAX) < total;
}
#else
static bool bch2_target_congested(struct bch_fs *c, u16 target)
{
return false;
}
#endif
/* Cache promotion on read */
struct promote_op {
struct rcu_head rcu;
u64 start_time;
struct rhash_head hash;
struct bpos pos;
struct data_update write;
struct bio_vec bi_inline_vecs[]; /* must be last */
};
static const struct rhashtable_params bch_promote_params = {
.head_offset = offsetof(struct promote_op, hash),
.key_offset = offsetof(struct promote_op, pos),
.key_len = sizeof(struct bpos),
};
static inline int should_promote(struct bch_fs *c, struct bkey_s_c k,
struct bpos pos,
struct bch_io_opts opts,
unsigned flags)
{
BUG_ON(!opts.promote_target);
if (!(flags & BCH_READ_MAY_PROMOTE))
return -BCH_ERR_nopromote_may_not;
if (bch2_bkey_has_target(c, k, opts.promote_target))
return -BCH_ERR_nopromote_already_promoted;
if (bkey_extent_is_unwritten(k))
return -BCH_ERR_nopromote_unwritten;
if (bch2_target_congested(c, opts.promote_target))
return -BCH_ERR_nopromote_congested;
if (rhashtable_lookup_fast(&c->promote_table, &pos,
bch_promote_params))
return -BCH_ERR_nopromote_in_flight;
return 0;
}
static void promote_free(struct bch_fs *c, struct promote_op *op)
{
int ret;
bch2_data_update_exit(&op->write);
ret = rhashtable_remove_fast(&c->promote_table, &op->hash,
bch_promote_params);
BUG_ON(ret);
bch2_write_ref_put(c, BCH_WRITE_REF_promote);
kfree_rcu(op, rcu);
}
static void promote_done(struct bch_write_op *wop)
{
struct promote_op *op =
container_of(wop, struct promote_op, write.op);
struct bch_fs *c = op->write.op.c;
bch2_time_stats_update(&c->times[BCH_TIME_data_promote],
op->start_time);
promote_free(c, op);
}
static void promote_start(struct promote_op *op, struct bch_read_bio *rbio)
{
struct bio *bio = &op->write.op.wbio.bio;
trace_and_count(op->write.op.c, read_promote, &rbio->bio);
/* we now own pages: */
BUG_ON(!rbio->bounce);
BUG_ON(rbio->bio.bi_vcnt > bio->bi_max_vecs);
memcpy(bio->bi_io_vec, rbio->bio.bi_io_vec,
sizeof(struct bio_vec) * rbio->bio.bi_vcnt);
swap(bio->bi_vcnt, rbio->bio.bi_vcnt);
bch2_data_update_read_done(&op->write, rbio->pick.crc);
}
static struct promote_op *__promote_alloc(struct btree_trans *trans,
enum btree_id btree_id,
struct bkey_s_c k,
struct bpos pos,
struct extent_ptr_decoded *pick,
struct bch_io_opts opts,
unsigned sectors,
struct bch_read_bio **rbio)
{
struct bch_fs *c = trans->c;
struct promote_op *op = NULL;
struct bio *bio;
unsigned pages = DIV_ROUND_UP(sectors, PAGE_SECTORS);
int ret;
if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_promote))
return ERR_PTR(-BCH_ERR_nopromote_no_writes);
op = kzalloc(struct_size(op, bi_inline_vecs, pages), GFP_KERNEL);
if (!op) {
ret = -BCH_ERR_nopromote_enomem;
goto err;
}
op->start_time = local_clock();
op->pos = pos;
/*
* We don't use the mempool here because extents that aren't
* checksummed or compressed can be too big for the mempool:
*/
*rbio = kzalloc(sizeof(struct bch_read_bio) +
sizeof(struct bio_vec) * pages,
GFP_KERNEL);
if (!*rbio) {
ret = -BCH_ERR_nopromote_enomem;
goto err;
}
rbio_init(&(*rbio)->bio, opts);
bio_init(&(*rbio)->bio, NULL, (*rbio)->bio.bi_inline_vecs, pages, 0);
if (bch2_bio_alloc_pages(&(*rbio)->bio, sectors << 9, GFP_KERNEL)) {
ret = -BCH_ERR_nopromote_enomem;
goto err;
}
(*rbio)->bounce = true;
(*rbio)->split = true;
(*rbio)->kmalloc = true;
if (rhashtable_lookup_insert_fast(&c->promote_table, &op->hash,
bch_promote_params)) {
ret = -BCH_ERR_nopromote_in_flight;
goto err;
}
bio = &op->write.op.wbio.bio;
bio_init(bio, NULL, bio->bi_inline_vecs, pages, 0);
ret = bch2_data_update_init(trans, NULL, NULL, &op->write,
writepoint_hashed((unsigned long) current),
opts,
(struct data_update_opts) {
.target = opts.promote_target,
.extra_replicas = 1,
.write_flags = BCH_WRITE_ALLOC_NOWAIT|BCH_WRITE_CACHED,
},
btree_id, k);
/*
* possible errors: -BCH_ERR_nocow_lock_blocked,
* -BCH_ERR_ENOSPC_disk_reservation:
*/
if (ret) {
BUG_ON(rhashtable_remove_fast(&c->promote_table, &op->hash,
bch_promote_params));
goto err;
}
op->write.op.end_io = promote_done;
return op;
err:
if (*rbio)
bio_free_pages(&(*rbio)->bio);
kfree(*rbio);
*rbio = NULL;
kfree(op);
bch2_write_ref_put(c, BCH_WRITE_REF_promote);
return ERR_PTR(ret);
}
noinline
static struct promote_op *promote_alloc(struct btree_trans *trans,
struct bvec_iter iter,
struct bkey_s_c k,
struct extent_ptr_decoded *pick,
struct bch_io_opts opts,
unsigned flags,
struct bch_read_bio **rbio,
bool *bounce,
bool *read_full)
{
struct bch_fs *c = trans->c;
bool promote_full = *read_full || READ_ONCE(c->promote_whole_extents);
/* data might have to be decompressed in the write path: */
unsigned sectors = promote_full
? max(pick->crc.compressed_size, pick->crc.live_size)
: bvec_iter_sectors(iter);
struct bpos pos = promote_full
? bkey_start_pos(k.k)
: POS(k.k->p.inode, iter.bi_sector);
struct promote_op *promote;
int ret;
ret = should_promote(c, k, pos, opts, flags);
if (ret)
goto nopromote;
promote = __promote_alloc(trans,
k.k->type == KEY_TYPE_reflink_v
? BTREE_ID_reflink
: BTREE_ID_extents,
k, pos, pick, opts, sectors, rbio);
ret = PTR_ERR_OR_ZERO(promote);
if (ret)
goto nopromote;
*bounce = true;
*read_full = promote_full;
return promote;
nopromote:
trace_read_nopromote(c, ret);
return NULL;
}
/* Read */
#define READ_RETRY_AVOID 1
#define READ_RETRY 2
#define READ_ERR 3
enum rbio_context {
RBIO_CONTEXT_NULL,
RBIO_CONTEXT_HIGHPRI,
RBIO_CONTEXT_UNBOUND,
};
static inline struct bch_read_bio *
bch2_rbio_parent(struct bch_read_bio *rbio)
{
return rbio->split ? rbio->parent : rbio;
}
__always_inline
static void bch2_rbio_punt(struct bch_read_bio *rbio, work_func_t fn,
enum rbio_context context,
struct workqueue_struct *wq)
{
if (context <= rbio->context) {
fn(&rbio->work);
} else {
rbio->work.func = fn;
rbio->context = context;
queue_work(wq, &rbio->work);
}
}
static inline struct bch_read_bio *bch2_rbio_free(struct bch_read_bio *rbio)
{
BUG_ON(rbio->bounce && !rbio->split);
if (rbio->promote)
promote_free(rbio->c, rbio->promote);
rbio->promote = NULL;
if (rbio->bounce)
bch2_bio_free_pages_pool(rbio->c, &rbio->bio);
if (rbio->split) {
struct bch_read_bio *parent = rbio->parent;
if (rbio->kmalloc)
kfree(rbio);
else
bio_put(&rbio->bio);
rbio = parent;
}
return rbio;
}
/*
* Only called on a top level bch_read_bio to complete an entire read request,
* not a split:
*/
static void bch2_rbio_done(struct bch_read_bio *rbio)
{
if (rbio->start_time)
bch2_time_stats_update(&rbio->c->times[BCH_TIME_data_read],
rbio->start_time);
bio_endio(&rbio->bio);
}
static void bch2_read_retry_nodecode(struct bch_fs *c, struct bch_read_bio *rbio,
struct bvec_iter bvec_iter,
struct bch_io_failures *failed,
unsigned flags)
{
struct btree_trans *trans = bch2_trans_get(c);
struct btree_iter iter;
struct bkey_buf sk;
struct bkey_s_c k;
int ret;
flags &= ~BCH_READ_LAST_FRAGMENT;
flags |= BCH_READ_MUST_CLONE;
bch2_bkey_buf_init(&sk);
bch2_trans_iter_init(trans, &iter, rbio->data_btree,
rbio->read_pos, BTREE_ITER_SLOTS);
retry:
rbio->bio.bi_status = 0;
k = bch2_btree_iter_peek_slot(&iter);
if (bkey_err(k))
goto err;
bch2_bkey_buf_reassemble(&sk, c, k);
k = bkey_i_to_s_c(sk.k);
bch2_trans_unlock(trans);
if (!bch2_bkey_matches_ptr(c, k,
rbio->pick.ptr,
rbio->data_pos.offset -
rbio->pick.crc.offset)) {
/* extent we wanted to read no longer exists: */
rbio->hole = true;
goto out;
}
ret = __bch2_read_extent(trans, rbio, bvec_iter,
rbio->read_pos,
rbio->data_btree,
k, 0, failed, flags);
if (ret == READ_RETRY)
goto retry;
if (ret)
goto err;
out:
bch2_rbio_done(rbio);
bch2_trans_iter_exit(trans, &iter);
bch2_trans_put(trans);
bch2_bkey_buf_exit(&sk, c);
return;
err:
rbio->bio.bi_status = BLK_STS_IOERR;
goto out;
}
static void bch2_rbio_retry(struct work_struct *work)
{
struct bch_read_bio *rbio =
container_of(work, struct bch_read_bio, work);
struct bch_fs *c = rbio->c;
struct bvec_iter iter = rbio->bvec_iter;
unsigned flags = rbio->flags;
subvol_inum inum = {
.subvol = rbio->subvol,
.inum = rbio->read_pos.inode,
};
struct bch_io_failures failed = { .nr = 0 };
trace_and_count(c, read_retry, &rbio->bio);
if (rbio->retry == READ_RETRY_AVOID)
bch2_mark_io_failure(&failed, &rbio->pick);
rbio->bio.bi_status = 0;
rbio = bch2_rbio_free(rbio);
flags |= BCH_READ_IN_RETRY;
flags &= ~BCH_READ_MAY_PROMOTE;
if (flags & BCH_READ_NODECODE) {
bch2_read_retry_nodecode(c, rbio, iter, &failed, flags);
} else {
flags &= ~BCH_READ_LAST_FRAGMENT;
flags |= BCH_READ_MUST_CLONE;
__bch2_read(c, rbio, iter, inum, &failed, flags);
}
}
static void bch2_rbio_error(struct bch_read_bio *rbio, int retry,
blk_status_t error)
{
rbio->retry = retry;
if (rbio->flags & BCH_READ_IN_RETRY)
return;
if (retry == READ_ERR) {
rbio = bch2_rbio_free(rbio);
rbio->bio.bi_status = error;
bch2_rbio_done(rbio);
} else {
bch2_rbio_punt(rbio, bch2_rbio_retry,
RBIO_CONTEXT_UNBOUND, system_unbound_wq);
}
}
static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
struct bch_read_bio *rbio)
{
struct bch_fs *c = rbio->c;
u64 data_offset = rbio->data_pos.offset - rbio->pick.crc.offset;
struct bch_extent_crc_unpacked new_crc;
struct btree_iter iter;
struct bkey_i *new;
struct bkey_s_c k;
int ret = 0;
if (crc_is_compressed(rbio->pick.crc))
return 0;
k = bch2_bkey_get_iter(trans, &iter, rbio->data_btree, rbio->data_pos,
BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
if ((ret = bkey_err(k)))
goto out;
if (bversion_cmp(k.k->version, rbio->version) ||
!bch2_bkey_matches_ptr(c, k, rbio->pick.ptr, data_offset))
goto out;
/* Extent was merged? */
if (bkey_start_offset(k.k) < data_offset ||
k.k->p.offset > data_offset + rbio->pick.crc.uncompressed_size)
goto out;
if (bch2_rechecksum_bio(c, &rbio->bio, rbio->version,
rbio->pick.crc, NULL, &new_crc,
bkey_start_offset(k.k) - data_offset, k.k->size,
rbio->pick.crc.csum_type)) {
bch_err(c, "error verifying existing checksum while narrowing checksum (memory corruption?)");
ret = 0;
goto out;
}
/*
* going to be temporarily appending another checksum entry:
*/
new = bch2_trans_kmalloc(trans, bkey_bytes(k.k) +
sizeof(struct bch_extent_crc128));
if ((ret = PTR_ERR_OR_ZERO(new)))
goto out;
bkey_reassemble(new, k);
if (!bch2_bkey_narrow_crcs(new, new_crc))
goto out;
ret = bch2_trans_update(trans, &iter, new,
BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
out:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static noinline void bch2_rbio_narrow_crcs(struct bch_read_bio *rbio)
{
bch2_trans_do(rbio->c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
__bch2_rbio_narrow_crcs(trans, rbio));
}
/* Inner part that may run in process context */
static void __bch2_read_endio(struct work_struct *work)
{
struct bch_read_bio *rbio =
container_of(work, struct bch_read_bio, work);
struct bch_fs *c = rbio->c;
struct bch_dev *ca = bch_dev_bkey_exists(c, rbio->pick.ptr.dev);
struct bio *src = &rbio->bio;
struct bio *dst = &bch2_rbio_parent(rbio)->bio;
struct bvec_iter dst_iter = rbio->bvec_iter;
struct bch_extent_crc_unpacked crc = rbio->pick.crc;
struct nonce nonce = extent_nonce(rbio->version, crc);
unsigned nofs_flags;
struct bch_csum csum;
int ret;
nofs_flags = memalloc_nofs_save();
/* Reset iterator for checksumming and copying bounced data: */
if (rbio->bounce) {
src->bi_iter.bi_size = crc.compressed_size << 9;
src->bi_iter.bi_idx = 0;
src->bi_iter.bi_bvec_done = 0;
} else {
src->bi_iter = rbio->bvec_iter;
}
csum = bch2_checksum_bio(c, crc.csum_type, nonce, src);
if (bch2_crc_cmp(csum, rbio->pick.crc.csum) && !c->opts.no_data_io)
goto csum_err;
/*
* XXX
* We need to rework the narrow_crcs path to deliver the read completion
* first, and then punt to a different workqueue, otherwise we're
* holding up reads while doing btree updates which is bad for memory
* reclaim.
*/
if (unlikely(rbio->narrow_crcs))
bch2_rbio_narrow_crcs(rbio);
if (rbio->flags & BCH_READ_NODECODE)
goto nodecode;
/* Adjust crc to point to subset of data we want: */
crc.offset += rbio->offset_into_extent;
crc.live_size = bvec_iter_sectors(rbio->bvec_iter);
if (crc_is_compressed(crc)) {
ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
if (ret)
goto decrypt_err;
if (bch2_bio_uncompress(c, src, dst, dst_iter, crc) &&
!c->opts.no_data_io)
goto decompression_err;
} else {
/* don't need to decrypt the entire bio: */
nonce = nonce_add(nonce, crc.offset << 9);
bio_advance(src, crc.offset << 9);
BUG_ON(src->bi_iter.bi_size < dst_iter.bi_size);
src->bi_iter.bi_size = dst_iter.bi_size;
ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
if (ret)
goto decrypt_err;
if (rbio->bounce) {
struct bvec_iter src_iter = src->bi_iter;
bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
}
}
if (rbio->promote) {
/*
* Re encrypt data we decrypted, so it's consistent with
* rbio->crc:
*/
ret = bch2_encrypt_bio(c, crc.csum_type, nonce, src);
if (ret)
goto decrypt_err;
promote_start(rbio->promote, rbio);
rbio->promote = NULL;
}
nodecode:
if (likely(!(rbio->flags & BCH_READ_IN_RETRY))) {
rbio = bch2_rbio_free(rbio);
bch2_rbio_done(rbio);
}
out:
memalloc_nofs_restore(nofs_flags);
return;
csum_err:
/*
* Checksum error: if the bio wasn't bounced, we may have been
* reading into buffers owned by userspace (that userspace can
* scribble over) - retry the read, bouncing it this time:
*/
if (!rbio->bounce && (rbio->flags & BCH_READ_USER_MAPPED)) {
rbio->flags |= BCH_READ_MUST_BOUNCE;
bch2_rbio_error(rbio, READ_RETRY, BLK_STS_IOERR);
goto out;
}
struct printbuf buf = PRINTBUF;
buf.atomic++;
prt_str(&buf, "data ");
bch2_csum_err_msg(&buf, crc.csum_type, rbio->pick.crc.csum, csum);
bch_err_inum_offset_ratelimited(ca,
rbio->read_pos.inode,
rbio->read_pos.offset << 9,
"data %s", buf.buf);
printbuf_exit(&buf);
bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
goto out;
decompression_err:
bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode,
rbio->read_pos.offset << 9,
"decompression error");
bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR);
goto out;
decrypt_err:
bch_err_inum_offset_ratelimited(c, rbio->read_pos.inode,
rbio->read_pos.offset << 9,
"decrypt error");
bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR);
goto out;
}
static void bch2_read_endio(struct bio *bio)
{
struct bch_read_bio *rbio =
container_of(bio, struct bch_read_bio, bio);
struct bch_fs *c = rbio->c;
struct bch_dev *ca = bch_dev_bkey_exists(c, rbio->pick.ptr.dev);
struct workqueue_struct *wq = NULL;
enum rbio_context context = RBIO_CONTEXT_NULL;
if (rbio->have_ioref) {
bch2_latency_acct(ca, rbio->submit_time, READ);
percpu_ref_put(&ca->io_ref);
}
if (!rbio->split)
rbio->bio.bi_end_io = rbio->end_io;
if (bch2_dev_inum_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_read,
rbio->read_pos.inode,
rbio->read_pos.offset,
"data read error: %s",
bch2_blk_status_to_str(bio->bi_status))) {
bch2_rbio_error(rbio, READ_RETRY_AVOID, bio->bi_status);
return;
}
if (((rbio->flags & BCH_READ_RETRY_IF_STALE) && race_fault()) ||
ptr_stale(ca, &rbio->pick.ptr)) {
trace_and_count(c, read_reuse_race, &rbio->bio);
if (rbio->flags & BCH_READ_RETRY_IF_STALE)
bch2_rbio_error(rbio, READ_RETRY, BLK_STS_AGAIN);
else
bch2_rbio_error(rbio, READ_ERR, BLK_STS_AGAIN);
return;
}
if (rbio->narrow_crcs ||
rbio->promote ||
crc_is_compressed(rbio->pick.crc) ||
bch2_csum_type_is_encryption(rbio->pick.crc.csum_type))
context = RBIO_CONTEXT_UNBOUND, wq = system_unbound_wq;
else if (rbio->pick.crc.csum_type)
context = RBIO_CONTEXT_HIGHPRI, wq = system_highpri_wq;
bch2_rbio_punt(rbio, __bch2_read_endio, context, wq);
}
int __bch2_read_indirect_extent(struct btree_trans *trans,
unsigned *offset_into_extent,
struct bkey_buf *orig_k)
{
struct btree_iter iter;
struct bkey_s_c k;
u64 reflink_offset;
int ret;
reflink_offset = le64_to_cpu(bkey_i_to_reflink_p(orig_k->k)->v.idx) +
*offset_into_extent;
k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_reflink,
POS(0, reflink_offset), 0);
ret = bkey_err(k);
if (ret)
goto err;
if (k.k->type != KEY_TYPE_reflink_v &&
k.k->type != KEY_TYPE_indirect_inline_data) {
bch_err_inum_offset_ratelimited(trans->c,
orig_k->k->k.p.inode,
orig_k->k->k.p.offset << 9,
"%llu len %u points to nonexistent indirect extent %llu",
orig_k->k->k.p.offset,
orig_k->k->k.size,
reflink_offset);
bch2_inconsistent_error(trans->c);
ret = -EIO;
goto err;
}
*offset_into_extent = iter.pos.offset - bkey_start_offset(k.k);
bch2_bkey_buf_reassemble(orig_k, trans->c, k);
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static noinline void read_from_stale_dirty_pointer(struct btree_trans *trans,
struct bkey_s_c k,
struct bch_extent_ptr ptr)
{
struct bch_fs *c = trans->c;
struct bch_dev *ca = bch_dev_bkey_exists(c, ptr.dev);
struct btree_iter iter;
struct printbuf buf = PRINTBUF;
int ret;
bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
PTR_BUCKET_POS(c, &ptr),
BTREE_ITER_CACHED);
prt_printf(&buf, "Attempting to read from stale dirty pointer:");
printbuf_indent_add(&buf, 2);
prt_newline(&buf);
bch2_bkey_val_to_text(&buf, c, k);
prt_newline(&buf);
prt_printf(&buf, "memory gen: %u", *bucket_gen(ca, iter.pos.offset));
ret = lockrestart_do(trans, bkey_err(k = bch2_btree_iter_peek_slot(&iter)));
if (!ret) {
prt_newline(&buf);
bch2_bkey_val_to_text(&buf, c, k);
}
bch2_fs_inconsistent(c, "%s", buf.buf);
bch2_trans_iter_exit(trans, &iter);
printbuf_exit(&buf);
}
int __bch2_read_extent(struct btree_trans *trans, struct bch_read_bio *orig,
struct bvec_iter iter, struct bpos read_pos,
enum btree_id data_btree, struct bkey_s_c k,
unsigned offset_into_extent,
struct bch_io_failures *failed, unsigned flags)
{
struct bch_fs *c = trans->c;
struct extent_ptr_decoded pick;
struct bch_read_bio *rbio = NULL;
struct bch_dev *ca = NULL;
struct promote_op *promote = NULL;
bool bounce = false, read_full = false, narrow_crcs = false;
struct bpos data_pos = bkey_start_pos(k.k);
int pick_ret;
if (bkey_extent_is_inline_data(k.k)) {
unsigned bytes = min_t(unsigned, iter.bi_size,
bkey_inline_data_bytes(k.k));
swap(iter.bi_size, bytes);
memcpy_to_bio(&orig->bio, iter, bkey_inline_data_p(k));
swap(iter.bi_size, bytes);
bio_advance_iter(&orig->bio, &iter, bytes);
zero_fill_bio_iter(&orig->bio, iter);
goto out_read_done;
}
retry_pick:
pick_ret = bch2_bkey_pick_read_device(c, k, failed, &pick);
/* hole or reservation - just zero fill: */
if (!pick_ret)
goto hole;
if (pick_ret < 0) {
bch_err_inum_offset_ratelimited(c,
read_pos.inode, read_pos.offset << 9,
"no device to read from");
goto err;
}
ca = bch_dev_bkey_exists(c, pick.ptr.dev);
/*
* Stale dirty pointers are treated as IO errors, but @failed isn't
* allocated unless we're in the retry path - so if we're not in the
* retry path, don't check here, it'll be caught in bch2_read_endio()
* and we'll end up in the retry path:
*/
if ((flags & BCH_READ_IN_RETRY) &&
!pick.ptr.cached &&
unlikely(ptr_stale(ca, &pick.ptr))) {
read_from_stale_dirty_pointer(trans, k, pick.ptr);
bch2_mark_io_failure(failed, &pick);
goto retry_pick;
}
/*
* Unlock the iterator while the btree node's lock is still in
* cache, before doing the IO:
*/
bch2_trans_unlock(trans);
if (flags & BCH_READ_NODECODE) {
/*
* can happen if we retry, and the extent we were going to read
* has been merged in the meantime:
*/
if (pick.crc.compressed_size > orig->bio.bi_vcnt * PAGE_SECTORS)
goto hole;
iter.bi_size = pick.crc.compressed_size << 9;
goto get_bio;
}
if (!(flags & BCH_READ_LAST_FRAGMENT) ||
bio_flagged(&orig->bio, BIO_CHAIN))
flags |= BCH_READ_MUST_CLONE;
narrow_crcs = !(flags & BCH_READ_IN_RETRY) &&
bch2_can_narrow_extent_crcs(k, pick.crc);
if (narrow_crcs && (flags & BCH_READ_USER_MAPPED))
flags |= BCH_READ_MUST_BOUNCE;
EBUG_ON(offset_into_extent + bvec_iter_sectors(iter) > k.k->size);
if (crc_is_compressed(pick.crc) ||
(pick.crc.csum_type != BCH_CSUM_none &&
(bvec_iter_sectors(iter) != pick.crc.uncompressed_size ||
(bch2_csum_type_is_encryption(pick.crc.csum_type) &&
(flags & BCH_READ_USER_MAPPED)) ||
(flags & BCH_READ_MUST_BOUNCE)))) {
read_full = true;
bounce = true;
}
if (orig->opts.promote_target)
promote = promote_alloc(trans, iter, k, &pick, orig->opts, flags,
&rbio, &bounce, &read_full);
if (!read_full) {
EBUG_ON(crc_is_compressed(pick.crc));
EBUG_ON(pick.crc.csum_type &&
(bvec_iter_sectors(iter) != pick.crc.uncompressed_size ||
bvec_iter_sectors(iter) != pick.crc.live_size ||
pick.crc.offset ||
offset_into_extent));
data_pos.offset += offset_into_extent;
pick.ptr.offset += pick.crc.offset +
offset_into_extent;
offset_into_extent = 0;
pick.crc.compressed_size = bvec_iter_sectors(iter);
pick.crc.uncompressed_size = bvec_iter_sectors(iter);
pick.crc.offset = 0;
pick.crc.live_size = bvec_iter_sectors(iter);
}
get_bio:
if (rbio) {
/*
* promote already allocated bounce rbio:
* promote needs to allocate a bio big enough for uncompressing
* data in the write path, but we're not going to use it all
* here:
*/
EBUG_ON(rbio->bio.bi_iter.bi_size <
pick.crc.compressed_size << 9);
rbio->bio.bi_iter.bi_size =
pick.crc.compressed_size << 9;
} else if (bounce) {
unsigned sectors = pick.crc.compressed_size;
rbio = rbio_init(bio_alloc_bioset(NULL,
DIV_ROUND_UP(sectors, PAGE_SECTORS),
0,
GFP_NOFS,
&c->bio_read_split),
orig->opts);
bch2_bio_alloc_pages_pool(c, &rbio->bio, sectors << 9);
rbio->bounce = true;
rbio->split = true;
} else if (flags & BCH_READ_MUST_CLONE) {
/*
* Have to clone if there were any splits, due to error
* reporting issues (if a split errored, and retrying didn't
* work, when it reports the error to its parent (us) we don't
* know if the error was from our bio, and we should retry, or
* from the whole bio, in which case we don't want to retry and
* lose the error)
*/
rbio = rbio_init(bio_alloc_clone(NULL, &orig->bio, GFP_NOFS,
&c->bio_read_split),
orig->opts);
rbio->bio.bi_iter = iter;
rbio->split = true;
} else {
rbio = orig;
rbio->bio.bi_iter = iter;
EBUG_ON(bio_flagged(&rbio->bio, BIO_CHAIN));
}
EBUG_ON(bio_sectors(&rbio->bio) != pick.crc.compressed_size);
rbio->c = c;
rbio->submit_time = local_clock();
if (rbio->split)
rbio->parent = orig;
else
rbio->end_io = orig->bio.bi_end_io;
rbio->bvec_iter = iter;
rbio->offset_into_extent= offset_into_extent;
rbio->flags = flags;
rbio->have_ioref = pick_ret > 0 && bch2_dev_get_ioref(ca, READ);
rbio->narrow_crcs = narrow_crcs;
rbio->hole = 0;
rbio->retry = 0;
rbio->context = 0;
/* XXX: only initialize this if needed */
rbio->devs_have = bch2_bkey_devs(k);
rbio->pick = pick;
rbio->subvol = orig->subvol;
rbio->read_pos = read_pos;
rbio->data_btree = data_btree;
rbio->data_pos = data_pos;
rbio->version = k.k->version;
rbio->promote = promote;
INIT_WORK(&rbio->work, NULL);
rbio->bio.bi_opf = orig->bio.bi_opf;
rbio->bio.bi_iter.bi_sector = pick.ptr.offset;
rbio->bio.bi_end_io = bch2_read_endio;
if (rbio->bounce)
trace_and_count(c, read_bounce, &rbio->bio);
this_cpu_add(c->counters[BCH_COUNTER_io_read], bio_sectors(&rbio->bio));
bch2_increment_clock(c, bio_sectors(&rbio->bio), READ);
/*
* If it's being moved internally, we don't want to flag it as a cache
* hit:
*/
if (pick.ptr.cached && !(flags & BCH_READ_NODECODE))
bch2_bucket_io_time_reset(trans, pick.ptr.dev,
PTR_BUCKET_NR(ca, &pick.ptr), READ);
if (!(flags & (BCH_READ_IN_RETRY|BCH_READ_LAST_FRAGMENT))) {
bio_inc_remaining(&orig->bio);
trace_and_count(c, read_split, &orig->bio);
}
if (!rbio->pick.idx) {
if (!rbio->have_ioref) {
bch_err_inum_offset_ratelimited(c,
read_pos.inode,
read_pos.offset << 9,
"no device to read from");
bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
goto out;
}
this_cpu_add(ca->io_done->sectors[READ][BCH_DATA_user],
bio_sectors(&rbio->bio));
bio_set_dev(&rbio->bio, ca->disk_sb.bdev);
if (unlikely(c->opts.no_data_io)) {
if (likely(!(flags & BCH_READ_IN_RETRY)))
bio_endio(&rbio->bio);
} else {
if (likely(!(flags & BCH_READ_IN_RETRY)))
submit_bio(&rbio->bio);
else
submit_bio_wait(&rbio->bio);
}
/*
* We just submitted IO which may block, we expect relock fail
* events and shouldn't count them:
*/
trans->notrace_relock_fail = true;
} else {
/* Attempting reconstruct read: */
if (bch2_ec_read_extent(trans, rbio)) {
bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
goto out;
}
if (likely(!(flags & BCH_READ_IN_RETRY)))
bio_endio(&rbio->bio);
}
out:
if (likely(!(flags & BCH_READ_IN_RETRY))) {
return 0;
} else {
int ret;
rbio->context = RBIO_CONTEXT_UNBOUND;
bch2_read_endio(&rbio->bio);
ret = rbio->retry;
rbio = bch2_rbio_free(rbio);
if (ret == READ_RETRY_AVOID) {
bch2_mark_io_failure(failed, &pick);
ret = READ_RETRY;
}
if (!ret)
goto out_read_done;
return ret;
}
err:
if (flags & BCH_READ_IN_RETRY)
return READ_ERR;
orig->bio.bi_status = BLK_STS_IOERR;
goto out_read_done;
hole:
/*
* won't normally happen in the BCH_READ_NODECODE
* (bch2_move_extent()) path, but if we retry and the extent we wanted
* to read no longer exists we have to signal that:
*/
if (flags & BCH_READ_NODECODE)
orig->hole = true;
zero_fill_bio_iter(&orig->bio, iter);
out_read_done:
if (flags & BCH_READ_LAST_FRAGMENT)
bch2_rbio_done(orig);
return 0;
}
void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
struct bvec_iter bvec_iter, subvol_inum inum,
struct bch_io_failures *failed, unsigned flags)
{
struct btree_trans *trans = bch2_trans_get(c);
struct btree_iter iter;
struct bkey_buf sk;
struct bkey_s_c k;
u32 snapshot;
int ret;
BUG_ON(flags & BCH_READ_NODECODE);
bch2_bkey_buf_init(&sk);
retry:
bch2_trans_begin(trans);
iter = (struct btree_iter) { NULL };
ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
if (ret)
goto err;
bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
SPOS(inum.inum, bvec_iter.bi_sector, snapshot),
BTREE_ITER_SLOTS);
while (1) {
unsigned bytes, sectors, offset_into_extent;
enum btree_id data_btree = BTREE_ID_extents;
/*
* read_extent -> io_time_reset may cause a transaction restart
* without returning an error, we need to check for that here:
*/
ret = bch2_trans_relock(trans);
if (ret)
break;
bch2_btree_iter_set_pos(&iter,
POS(inum.inum, bvec_iter.bi_sector));
k = bch2_btree_iter_peek_slot(&iter);
ret = bkey_err(k);
if (ret)
break;
offset_into_extent = iter.pos.offset -
bkey_start_offset(k.k);
sectors = k.k->size - offset_into_extent;
bch2_bkey_buf_reassemble(&sk, c, k);
ret = bch2_read_indirect_extent(trans, &data_btree,
&offset_into_extent, &sk);
if (ret)
break;
k = bkey_i_to_s_c(sk.k);
/*
* With indirect extents, the amount of data to read is the min
* of the original extent and the indirect extent:
*/
sectors = min(sectors, k.k->size - offset_into_extent);
bytes = min(sectors, bvec_iter_sectors(bvec_iter)) << 9;
swap(bvec_iter.bi_size, bytes);
if (bvec_iter.bi_size == bytes)
flags |= BCH_READ_LAST_FRAGMENT;
ret = __bch2_read_extent(trans, rbio, bvec_iter, iter.pos,
data_btree, k,
offset_into_extent, failed, flags);
if (ret)
break;
if (flags & BCH_READ_LAST_FRAGMENT)
break;
swap(bvec_iter.bi_size, bytes);
bio_advance_iter(&rbio->bio, &bvec_iter, bytes);
ret = btree_trans_too_many_iters(trans);
if (ret)
break;
}
err:
bch2_trans_iter_exit(trans, &iter);
if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
ret == READ_RETRY ||
ret == READ_RETRY_AVOID)
goto retry;
bch2_trans_put(trans);
bch2_bkey_buf_exit(&sk, c);
if (ret) {
bch_err_inum_offset_ratelimited(c, inum.inum,
bvec_iter.bi_sector << 9,
"read error %i from btree lookup", ret);
rbio->bio.bi_status = BLK_STS_IOERR;
bch2_rbio_done(rbio);
}
}
void bch2_fs_io_read_exit(struct bch_fs *c)
{
if (c->promote_table.tbl)
rhashtable_destroy(&c->promote_table);
bioset_exit(&c->bio_read_split);
bioset_exit(&c->bio_read);
}
int bch2_fs_io_read_init(struct bch_fs *c)
{
if (bioset_init(&c->bio_read, 1, offsetof(struct bch_read_bio, bio),
BIOSET_NEED_BVECS))
return -BCH_ERR_ENOMEM_bio_read_init;
if (bioset_init(&c->bio_read_split, 1, offsetof(struct bch_read_bio, bio),
BIOSET_NEED_BVECS))
return -BCH_ERR_ENOMEM_bio_read_split_init;
if (rhashtable_init(&c->promote_table, &bch_promote_params))
return -BCH_ERR_ENOMEM_promote_table_init;
return 0;
}
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