bcachefs: BCH_READ_data_update -> bch_read_bio.data_update

Read flags are codepath dependent and change as they're passed around,
while the fields in rbio._state are mostly fixed properties of that
particular object.

Losing track of BCH_READ_data_update would be bad, and previously it was
not obvious if it was always correctly set in the rbio, so this is a
safety cleanup.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/data_update.c

@@ -700,6 +700,7 @@ int bch2_data_update_bios_init(struct data_update *m, struct bch_fs *c,
 	}
 
 	rbio_init(&m->rbio.bio, c, *io_opts, NULL);
+	m->rbio.data_update		= true;
 	m->rbio.bio.bi_iter.bi_size	= buf_bytes;
 	m->rbio.bio.bi_iter.bi_sector	= bkey_start_offset(&m->k.k->k);
 	m->op.wbio.bio.bi_ioprio	= IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0);

fs/bcachefs/io_read.c

@@ -103,14 +103,21 @@ static inline bool have_io_error(struct bch_io_failures *failed)
 	return failed && failed->nr;
 }
 
-static bool ptr_being_rewritten(struct bch_read_bio *orig,
-				unsigned dev,
-				unsigned flags)
+static inline struct data_update *rbio_data_update(struct bch_read_bio *rbio)
 {
-	if (!(flags & BCH_READ_data_update))
+	EBUG_ON(rbio->split);
+
+	return rbio->data_update
+		? container_of(rbio, struct data_update, rbio)
+		: NULL;
+}
+
+static bool ptr_being_rewritten(struct bch_read_bio *orig, unsigned dev)
+{
+	struct data_update *u = rbio_data_update(orig);
+	if (!u)
 		return false;
 
-	struct data_update *u = container_of(orig, struct data_update, rbio);
 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(u->k.k));
 	unsigned i = 0;
 	bkey_for_each_ptr(ptrs, ptr) {
@@ -199,7 +206,6 @@ static struct bch_read_bio *__promote_alloc(struct btree_trans *trans,
 					    struct bpos pos,
 					    struct extent_ptr_decoded *pick,
 					    unsigned sectors,
-					    unsigned flags,
 					    struct bch_read_bio *orig,
 					    struct bch_io_failures *failed)
 {
@@ -220,7 +226,7 @@ static struct bch_read_bio *__promote_alloc(struct btree_trans *trans,
 		unsigned ptr_bit = 1;
 		bkey_for_each_ptr(ptrs, ptr) {
 			if (bch2_dev_io_failures(failed, ptr->dev) &&
-			    !ptr_being_rewritten(orig, ptr->dev, flags))
+			    !ptr_being_rewritten(orig, ptr->dev))
 				update_opts.rewrite_ptrs |= ptr_bit;
 			ptr_bit <<= 1;
 		}
@@ -314,7 +320,7 @@ static struct bch_read_bio *promote_alloc(struct btree_trans *trans,
 				k.k->type == KEY_TYPE_reflink_v
 				? BTREE_ID_reflink
 				: BTREE_ID_extents,
-				k, pos, pick, sectors, flags, orig, failed);
+				k, pos, pick, sectors, orig, failed);
 	if (!promote)
 		return NULL;
 
@@ -342,7 +348,7 @@ static int bch2_read_err_msg_trans(struct btree_trans *trans, struct printbuf *o
 	if (ret)
 		return ret;
 
-	if (rbio->flags & BCH_READ_data_update)
+	if (rbio->data_update)
 		prt_str(out, "(internal move) ");
 
 	return 0;
@@ -505,7 +511,7 @@ static void bch2_rbio_retry(struct work_struct *work)
 	flags &= ~BCH_READ_last_fragment;
 	flags |= BCH_READ_must_clone;
 
-	int ret = flags & BCH_READ_data_update
+	int ret = rbio->data_update
 		? bch2_read_retry_nodecode(c, rbio, iter, &failed, flags)
 		: __bch2_read(c, rbio, iter, inum, &failed, flags);
 
@@ -519,7 +525,7 @@ static void bch2_rbio_retry(struct work_struct *work)
 			bch2_inum_offset_err_msg_trans(trans, &buf,
 					(subvol_inum) { subvol, read_pos.inode },
 					read_pos.offset << 9));
-		if (rbio->flags & BCH_READ_data_update)
+		if (rbio->data_update)
 			prt_str(&buf, "(internal move) ");
 		prt_str(&buf, "successful retry");
 
@@ -712,9 +718,10 @@ static void __bch2_read_endio(struct work_struct *work)
 		container_of(work, struct bch_read_bio, work);
 	struct bch_fs *c	= rbio->c;
 	struct bch_dev *ca = rbio->have_ioref ? bch2_dev_have_ref(c, rbio->pick.ptr.dev) : NULL;
-	struct bio *src		= &rbio->bio;
-	struct bio *dst		= &bch2_rbio_parent(rbio)->bio;
-	struct bvec_iter dst_iter = rbio->bvec_iter;
+	struct bch_read_bio *parent	= bch2_rbio_parent(rbio);
+	struct bio *src			= &rbio->bio;
+	struct bio *dst			= &parent->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;
@@ -764,7 +771,7 @@ static void __bch2_read_endio(struct work_struct *work)
 	if (unlikely(rbio->narrow_crcs))
 		bch2_rbio_narrow_crcs(rbio);
 
-	if (likely(!(rbio->flags & BCH_READ_data_update))) {
+	if (likely(!parent->data_update)) {
 		/* 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);
@@ -934,6 +941,7 @@ int __bch2_read_extent(struct btree_trans *trans, struct bch_read_bio *orig,
 	struct bch_read_bio *rbio = NULL;
 	bool bounce = false, read_full = false, narrow_crcs = false;
 	struct bpos data_pos = bkey_start_pos(k.k);
+	struct data_update *u = rbio_data_update(orig);
 	int ret = 0;
 
 	if (bkey_extent_is_inline_data(k.k)) {
@@ -997,7 +1005,7 @@ retry_pick:
 		goto retry_pick;
 	}
 
-	if (!(flags & BCH_READ_data_update)) {
+	if (likely(!u)) {
 		if (!(flags & BCH_READ_last_fragment) ||
 		    bio_flagged(&orig->bio, BIO_CHAIN))
 			flags |= BCH_READ_must_clone;
@@ -1020,12 +1028,10 @@ retry_pick:
 			bounce = true;
 		}
 	} else {
-		read_full = true;
 		/*
 		 * can happen if we retry, and the extent we were going to read
 		 * has been merged in the meantime:
 		 */
-		struct data_update *u = container_of(orig, struct data_update, rbio);
 		if (pick.crc.compressed_size > u->op.wbio.bio.bi_iter.bi_size) {
 			if (ca)
 				percpu_ref_put(&ca->io_ref);
@@ -1034,6 +1040,7 @@ retry_pick:
 		}
 
 		iter.bi_size	= pick.crc.compressed_size << 9;
+		read_full = true;
 	}
 
 	if (orig->opts.promote_target || have_io_error(failed))
@@ -1127,7 +1134,7 @@ retry_pick:
 	if (rbio->bounce)
 		trace_and_count(c, io_read_bounce, &rbio->bio);
 
-	if (!(flags & BCH_READ_data_update))
+	if (!u)
 		this_cpu_add(c->counters[BCH_COUNTER_io_read], bio_sectors(&rbio->bio));
 	else
 		this_cpu_add(c->counters[BCH_COUNTER_io_move_read], bio_sectors(&rbio->bio));
@@ -1137,7 +1144,7 @@ retry_pick:
 	 * If it's being moved internally, we don't want to flag it as a cache
 	 * hit:
 	 */
-	if (ca && pick.ptr.cached && !(flags & BCH_READ_data_update))
+	if (ca && pick.ptr.cached && !u)
 		bch2_bucket_io_time_reset(trans, pick.ptr.dev,
 			PTR_BUCKET_NR(ca, &pick.ptr), READ);
 
@@ -1234,11 +1241,11 @@ hole:
 	this_cpu_add(c->counters[BCH_COUNTER_io_read_hole],
 		     bvec_iter_sectors(iter));
 	/*
-	 * won't normally happen in the BCH_READ_data_update
-	 * (bch2_move_extent()) path, but if we retry and the extent we wanted
-	 * to read no longer exists we have to signal that:
+	 * won't normally happen in the data update (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_data_update)
+	if (u)
 		orig->ret = -BCH_ERR_data_read_key_overwritten;
 
 	zero_fill_bio_iter(&orig->bio, iter);
@@ -1259,7 +1266,7 @@ int __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
 	struct bkey_s_c k;
 	int ret;
 
-	BUG_ON(flags & BCH_READ_data_update);
+	EBUG_ON(rbio->data_update);
 
 	bch2_bkey_buf_init(&sk);
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,

fs/bcachefs/io_read.h

@@ -35,7 +35,8 @@ struct bch_read_bio {
 	u16			flags;
 	union {
 	struct {
-	u16			promote:1,
+	u16			data_update:1,
+				promote:1,
 				bounce:1,
 				split:1,
 				have_ioref:1,
@@ -108,7 +109,6 @@ static inline int bch2_read_indirect_extent(struct btree_trans *trans,
 	x(retry_if_stale)		\
 	x(may_promote)			\
 	x(user_mapped)			\
-	x(data_update)			\
 	x(last_fragment)		\
 	x(must_bounce)			\
 	x(must_clone)			\
@@ -161,12 +161,13 @@ static inline struct bch_read_bio *rbio_init_fragment(struct bio *bio,
 {
 	struct bch_read_bio *rbio = to_rbio(bio);
 
-	rbio->c		= orig->c;
-	rbio->_state	= 0;
-	rbio->ret	= 0;
-	rbio->split	= true;
-	rbio->parent	= orig;
-	rbio->opts	= orig->opts;
+	rbio->c			= orig->c;
+	rbio->_state		= 0;
+	rbio->flags		= 0;
+	rbio->ret		= 0;
+	rbio->split		= true;
+	rbio->parent		= orig;
+	rbio->opts		= orig->opts;
 	return rbio;
 }
 
@@ -180,7 +181,8 @@ static inline struct bch_read_bio *rbio_init(struct bio *bio,
 	rbio->start_time	= local_clock();
 	rbio->c			= c;
 	rbio->_state		= 0;
-	rbio->ret	= 0;
+	rbio->flags		= 0;
+	rbio->ret		= 0;
 	rbio->opts		= opts;
 	rbio->bio.bi_end_io	= end_io;
 	return rbio;

fs/bcachefs/move.c

@@ -359,7 +359,6 @@ int bch2_move_extent(struct moving_context *ctxt,
 			   bkey_start_pos(k.k),
 			   iter->btree_id, k, 0,
 			   NULL,
-			   BCH_READ_data_update|
 			   BCH_READ_last_fragment,
 			   data_opts.scrub ?  data_opts.read_dev : -1);
 	return 0;