]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/io.c
Update bcachefs sources to 6c5219caf0 bcachefs: Rev the on disk format version for...
[bcachefs-tools-debian] / libbcachefs / io.c
index 9b6aece794f2c9cf3ec74fe633a69ac4a385696f..0bc72d2a4dd4cf09bc6b11b9e22a8afcb43977f8 100644 (file)
@@ -27,6 +27,7 @@
 #include "keylist.h"
 #include "move.h"
 #include "rebalance.h"
+#include "subvolume.h"
 #include "super.h"
 #include "super-io.h"
 
@@ -192,7 +193,7 @@ int bch2_sum_sector_overwrites(struct btree_trans *trans,
                               s64 *disk_sectors_delta)
 {
        struct bch_fs *c = trans->c;
-       struct btree_iter *iter;
+       struct btree_iter iter;
        struct bkey_s_c old;
        unsigned new_replicas = bch2_bkey_replicas(c, bkey_i_to_s_c(new));
        bool new_compressed = bch2_bkey_sectors_compressed(bkey_i_to_s_c(new));
@@ -203,7 +204,7 @@ int bch2_sum_sector_overwrites(struct btree_trans *trans,
        *i_sectors_delta        = 0;
        *disk_sectors_delta     = 0;
 
-       iter = bch2_trans_copy_iter(trans, extent_iter);
+       bch2_trans_copy_iter(&iter, extent_iter);
 
        for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, old, ret) {
                s64 sectors = min(new->k.p.offset, old.k->p.offset) -
@@ -220,7 +221,8 @@ int bch2_sum_sector_overwrites(struct btree_trans *trans,
                        : 0;
 
                if (!*usage_increasing &&
-                   (new_replicas > bch2_bkey_replicas(c, old) ||
+                   (new->k.p.snapshot != old.k->p.snapshot ||
+                    new_replicas > bch2_bkey_replicas(c, old) ||
                     (!new_compressed && bch2_bkey_sectors_compressed(old))))
                        *usage_increasing = true;
 
@@ -235,8 +237,12 @@ int bch2_sum_sector_overwrites(struct btree_trans *trans,
                         * writing to, because i_size could be up to one block
                         * less:
                         */
-                       if (!bkey_cmp(old.k->p, new->k.p))
-                               old = bch2_btree_iter_next(iter);
+                       if (!bkey_cmp(old.k->p, new->k.p)) {
+                               old = bch2_btree_iter_next(&iter);
+                               ret = bkey_err(old);
+                               if (ret)
+                                       break;
+                       }
 
                        if (old.k && !bkey_err(old) &&
                            old.k->p.inode == extent_iter->pos.inode &&
@@ -247,11 +253,12 @@ int bch2_sum_sector_overwrites(struct btree_trans *trans,
                }
        }
 
-       bch2_trans_iter_put(trans, iter);
+       bch2_trans_iter_exit(trans, &iter);
        return ret;
 }
 
 int bch2_extent_update(struct btree_trans *trans,
+                      subvol_inum inum,
                       struct btree_iter *iter,
                       struct bkey_i *k,
                       struct disk_reservation *disk_res,
@@ -262,11 +269,22 @@ int bch2_extent_update(struct btree_trans *trans,
 {
        /* this must live until after bch2_trans_commit(): */
        struct bkey_inode_buf inode_p;
+       struct bpos next_pos;
        bool extending = false, usage_increasing;
        s64 i_sectors_delta = 0, disk_sectors_delta = 0;
        int ret;
 
-       ret = bch2_extent_trim_atomic(k, iter);
+       /*
+        * This traverses us the iterator without changing iter->path->pos to
+        * search_key() (which is pos + 1 for extents): we want there to be a
+        * path already traversed at iter->pos because
+        * bch2_trans_extent_update() will use it to attempt extent merging
+        */
+       ret = __bch2_btree_iter_traverse(iter);
+       if (ret)
+               return ret;
+
+       ret = bch2_extent_trim_atomic(trans, iter, k);
        if (ret)
                return ret;
 
@@ -296,13 +314,13 @@ int bch2_extent_update(struct btree_trans *trans,
                : 0;
 
        if (i_sectors_delta || new_i_size) {
-               struct btree_iter *inode_iter;
+               struct btree_iter inode_iter;
                struct bch_inode_unpacked inode_u;
 
-               inode_iter = bch2_inode_peek(trans, &inode_u,
-                               k->k.p.inode, BTREE_ITER_INTENT);
-               if (IS_ERR(inode_iter))
-                       return PTR_ERR(inode_iter);
+               ret = bch2_inode_peek(trans, &inode_iter, &inode_u, inum,
+                                     BTREE_ITER_INTENT);
+               if (ret)
+                       return ret;
 
                /*
                 * XXX:
@@ -329,13 +347,18 @@ int bch2_extent_update(struct btree_trans *trans,
 
                        inode_p.inode.k.p.snapshot = iter->snapshot;
 
-                       bch2_trans_update(trans, inode_iter,
+                       ret = bch2_trans_update(trans, &inode_iter,
                                          &inode_p.inode.k_i, 0);
                }
 
-               bch2_trans_iter_put(trans, inode_iter);
+               bch2_trans_iter_exit(trans, &inode_iter);
+
+               if (ret)
+                       return ret;
        }
 
+       next_pos = k->k.p;
+
        ret =   bch2_trans_update(trans, iter, k, 0) ?:
                bch2_trans_commit(trans, disk_res, journal_seq,
                                BTREE_INSERT_NOCHECK_RW|
@@ -344,28 +367,44 @@ int bch2_extent_update(struct btree_trans *trans,
        if (ret)
                return ret;
 
+       bch2_btree_iter_set_pos(iter, next_pos);
+
        if (i_sectors_delta_total)
                *i_sectors_delta_total += i_sectors_delta;
        return 0;
 }
 
+/*
+ * Returns -EINTR if we had to drop locks:
+ */
 int bch2_fpunch_at(struct btree_trans *trans, struct btree_iter *iter,
-                  struct bpos end, u64 *journal_seq,
-                  s64 *i_sectors_delta)
+                  subvol_inum inum, u64 end,
+                  u64 *journal_seq, 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 ((k = bch2_btree_iter_peek(iter)).k &&
-              bkey_cmp(iter->pos, end) < 0) {
+       while (1) {
                struct disk_reservation disk_res =
                        bch2_disk_reservation_init(c, 0);
                struct bkey_i delete;
 
                bch2_trans_begin(trans);
 
+               ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+               if (ret)
+                       goto btree_err;
+
+               bch2_btree_iter_set_snapshot(iter, snapshot);
+
+               k = bch2_btree_iter_peek(iter);
+               if (bkey_cmp(iter->pos, end_pos) >= 0)
+                       break;
+
                ret = bkey_err(k);
                if (ret)
                        goto btree_err;
@@ -375,9 +414,9 @@ int bch2_fpunch_at(struct btree_trans *trans, struct btree_iter *iter,
 
                /* create the biggest key we can */
                bch2_key_resize(&delete.k, max_sectors);
-               bch2_cut_back(end, &delete);
+               bch2_cut_back(end_pos, &delete);
 
-               ret = bch2_extent_update(trans, iter, &delete,
+               ret = bch2_extent_update(trans, inum, iter, &delete,
                                &disk_res, journal_seq,
                                0, i_sectors_delta, false);
                bch2_disk_reservation_put(c, &disk_res);
@@ -390,36 +429,31 @@ btree_err:
                        break;
        }
 
-       if (bkey_cmp(iter->pos, end) > 0) {
-               bch2_btree_iter_set_pos(iter, end);
-               ret = bch2_btree_iter_traverse(iter);
-       }
+       if (bkey_cmp(iter->pos, end_pos) > 0)
+               bch2_btree_iter_set_pos(iter, end_pos);
 
        return ret ?: ret2;
 }
 
-int bch2_fpunch(struct bch_fs *c, u64 inum, u64 start, u64 end,
+int bch2_fpunch(struct bch_fs *c, subvol_inum inum, u64 start, u64 end,
                u64 *journal_seq, s64 *i_sectors_delta)
 {
        struct btree_trans trans;
-       struct btree_iter *iter;
-       int ret = 0;
+       struct btree_iter iter;
+       int ret;
 
        bch2_trans_init(&trans, c, BTREE_ITER_MAX, 1024);
-       iter = bch2_trans_get_iter(&trans, BTREE_ID_extents,
-                                  POS(inum, start),
-                                  BTREE_ITER_INTENT);
+       bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
+                            POS(inum.inum, start),
+                            BTREE_ITER_INTENT);
 
-       ret = bch2_fpunch_at(&trans, iter, POS(inum, end),
+       ret = bch2_fpunch_at(&trans, &iter, inum, end,
                             journal_seq, i_sectors_delta);
 
-       bch2_trans_iter_put(&trans, iter);
+       bch2_trans_iter_exit(&trans, &iter);
        bch2_trans_exit(&trans);
 
-       if (ret == -EINTR)
-               ret = 0;
-
-       return ret;
+       return ret == -EINTR ? 0 : ret;
 }
 
 int bch2_write_index_default(struct bch_write_op *op)
@@ -429,41 +463,52 @@ int bch2_write_index_default(struct bch_write_op *op)
        struct keylist *keys = &op->insert_keys;
        struct bkey_i *k = bch2_keylist_front(keys);
        struct btree_trans trans;
-       struct btree_iter *iter;
+       struct btree_iter iter;
+       subvol_inum inum = {
+               .subvol = op->subvol,
+               .inum   = k->k.p.inode,
+       };
        int ret;
 
+       BUG_ON(!inum.subvol);
+
        bch2_bkey_buf_init(&sk);
        bch2_trans_init(&trans, c, BTREE_ITER_MAX, 1024);
 
-       iter = bch2_trans_get_iter(&trans, BTREE_ID_extents,
-                                  bkey_start_pos(&k->k),
-                                  BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-
        do {
                bch2_trans_begin(&trans);
 
                k = bch2_keylist_front(keys);
+               bch2_bkey_buf_copy(&sk, c, k);
 
-               k->k.p.snapshot = iter->snapshot;
+               ret = bch2_subvolume_get_snapshot(&trans, inum.subvol,
+                                                 &sk.k->k.p.snapshot);
+               if (ret == -EINTR)
+                       continue;
+               if (ret)
+                       break;
 
-               bch2_bkey_buf_realloc(&sk, c, k->k.u64s);
-               bkey_copy(sk.k, k);
-               bch2_cut_front(iter->pos, sk.k);
+               bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
+                                    bkey_start_pos(&sk.k->k),
+                                    BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
 
-               ret = bch2_extent_update(&trans, iter, sk.k,
+               ret = bch2_extent_update(&trans, inum, &iter, sk.k,
                                         &op->res, op_journal_seq(op),
                                         op->new_i_size, &op->i_sectors_delta,
                                         op->flags & BCH_WRITE_CHECK_ENOSPC);
+               bch2_trans_iter_exit(&trans, &iter);
+
                if (ret == -EINTR)
                        continue;
                if (ret)
                        break;
 
-               if (bkey_cmp(iter->pos, k->k.p) >= 0)
-                       bch2_keylist_pop_front(keys);
+               if (bkey_cmp(iter.pos, k->k.p) >= 0)
+                       bch2_keylist_pop_front(&op->insert_keys);
+               else
+                       bch2_cut_front(iter.pos, k);
        } while (!bch2_keylist_empty(keys));
 
-       bch2_trans_iter_put(&trans, iter);
        bch2_trans_exit(&trans);
        bch2_bkey_buf_exit(&sk, c);
 
@@ -1439,7 +1484,7 @@ static void promote_start(struct promote_op *op, struct bch_read_bio *rbio)
        bch2_migrate_read_done(&op->write, rbio);
 
        closure_init(cl, NULL);
-       closure_call(&op->write.op.cl, bch2_write, c->wq, cl);
+       closure_call(&op->write.op.cl, bch2_write, c->btree_update_wq, cl);
        closure_return_with_destructor(cl, promote_done);
 }
 
@@ -1624,12 +1669,12 @@ static void bch2_rbio_done(struct bch_read_bio *rbio)
 }
 
 static void bch2_read_retry_nodecode(struct bch_fs *c, struct bch_read_bio *rbio,
-                                    struct bvec_iter bvec_iter, u64 inode,
+                                    struct bvec_iter bvec_iter,
                                     struct bch_io_failures *failed,
                                     unsigned flags)
 {
        struct btree_trans trans;
-       struct btree_iter *iter;
+       struct btree_iter iter;
        struct bkey_buf sk;
        struct bkey_s_c k;
        int ret;
@@ -1640,12 +1685,12 @@ static void bch2_read_retry_nodecode(struct bch_fs *c, struct bch_read_bio *rbio
        bch2_bkey_buf_init(&sk);
        bch2_trans_init(&trans, c, 0, 0);
 
-       iter = bch2_trans_get_iter(&trans, rbio->data_btree,
-                                  rbio->read_pos, BTREE_ITER_SLOTS);
+       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);
+       k = bch2_btree_iter_peek_slot(&iter);
        if (bkey_err(k))
                goto err;
 
@@ -1672,7 +1717,7 @@ retry:
                goto err;
 out:
        bch2_rbio_done(rbio);
-       bch2_trans_iter_put(&trans, iter);
+       bch2_trans_iter_exit(&trans, &iter);
        bch2_trans_exit(&trans);
        bch2_bkey_buf_exit(&sk, c);
        return;
@@ -1688,7 +1733,10 @@ static void bch2_rbio_retry(struct work_struct *work)
        struct bch_fs *c        = rbio->c;
        struct bvec_iter iter   = rbio->bvec_iter;
        unsigned flags          = rbio->flags;
-       u64 inode               = rbio->read_pos.inode;
+       subvol_inum inum = {
+               .subvol = rbio->subvol,
+               .inum   = rbio->read_pos.inode,
+       };
        struct bch_io_failures failed = { .nr = 0 };
 
        trace_read_retry(&rbio->bio);
@@ -1704,12 +1752,12 @@ static void bch2_rbio_retry(struct work_struct *work)
        flags &= ~BCH_READ_MAY_PROMOTE;
 
        if (flags & BCH_READ_NODECODE) {
-               bch2_read_retry_nodecode(c, rbio, iter, inode, &failed, flags);
+               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, inode, &failed, flags);
+               __bch2_read(c, rbio, iter, inum, &failed, flags);
        }
 }
 
@@ -1738,7 +1786,7 @@ static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
        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 = NULL;
+       struct btree_iter iter;
        struct bkey_i *new;
        struct bkey_s_c k;
        int ret = 0;
@@ -1746,9 +1794,9 @@ static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
        if (crc_is_compressed(rbio->pick.crc))
                return 0;
 
-       iter = bch2_trans_get_iter(trans, rbio->data_btree, rbio->data_pos,
-                                  BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-       k = bch2_btree_iter_peek_slot(iter);
+       bch2_trans_iter_init(trans, &iter, rbio->data_btree, rbio->data_pos,
+                            BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+       k = bch2_btree_iter_peek_slot(&iter);
        if ((ret = bkey_err(k)))
                goto out;
 
@@ -1783,9 +1831,10 @@ static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
        if (!bch2_bkey_narrow_crcs(new, new_crc))
                goto out;
 
-       bch2_trans_update(trans, iter, new, 0);
+       ret = bch2_trans_update(trans, &iter, new,
+                               BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
 out:
-       bch2_trans_iter_put(trans, iter);
+       bch2_trans_iter_exit(trans, &iter);
        return ret;
 }
 
@@ -1807,8 +1856,11 @@ static void __bch2_read_endio(struct work_struct *work)
        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;
 
+       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;
@@ -1822,6 +1874,13 @@ static void __bch2_read_endio(struct work_struct *work)
        if (bch2_crc_cmp(csum, rbio->pick.crc.csum))
                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);
 
@@ -1866,6 +1925,8 @@ nodecode:
                rbio = bch2_rbio_free(rbio);
                bch2_rbio_done(rbio);
        }
+out:
+       memalloc_nofs_restore(nofs_flags);
        return;
 csum_err:
        /*
@@ -1876,7 +1937,7 @@ csum_err:
        if (!rbio->bounce && (rbio->flags & BCH_READ_USER_MAPPED)) {
                rbio->flags |= BCH_READ_MUST_BOUNCE;
                bch2_rbio_error(rbio, READ_RETRY, BLK_STS_IOERR);
-               return;
+               goto out;
        }
 
        bch2_dev_inum_io_error(ca, rbio->read_pos.inode, (u64) rbio->bvec_iter.bi_sector,
@@ -1884,12 +1945,12 @@ csum_err:
                rbio->pick.crc.csum.hi, rbio->pick.crc.csum.lo,
                csum.hi, csum.lo, crc.csum_type);
        bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
-       return;
+       goto out;
 decompression_err:
        bch_err_inum_ratelimited(c, rbio->read_pos.inode,
                                 "decompression error");
        bch2_rbio_error(rbio, READ_ERR, BLK_STS_IOERR);
-       return;
+       goto out;
 }
 
 static void bch2_read_endio(struct bio *bio)
@@ -1944,7 +2005,7 @@ int __bch2_read_indirect_extent(struct btree_trans *trans,
                                unsigned *offset_into_extent,
                                struct bkey_buf *orig_k)
 {
-       struct btree_iter *iter;
+       struct btree_iter iter;
        struct bkey_s_c k;
        u64 reflink_offset;
        int ret;
@@ -1952,10 +2013,10 @@ int __bch2_read_indirect_extent(struct btree_trans *trans,
        reflink_offset = le64_to_cpu(bkey_i_to_reflink_p(orig_k->k)->v.idx) +
                *offset_into_extent;
 
-       iter = bch2_trans_get_iter(trans, BTREE_ID_reflink,
-                                  POS(0, reflink_offset),
-                                  BTREE_ITER_SLOTS);
-       k = bch2_btree_iter_peek_slot(iter);
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_reflink,
+                            POS(0, reflink_offset),
+                            BTREE_ITER_SLOTS);
+       k = bch2_btree_iter_peek_slot(&iter);
        ret = bkey_err(k);
        if (ret)
                goto err;
@@ -1972,10 +2033,10 @@ int __bch2_read_indirect_extent(struct btree_trans *trans,
                goto err;
        }
 
-       *offset_into_extent = iter->pos.offset - bkey_start_offset(k.k);
+       *offset_into_extent = iter.pos.offset - bkey_start_offset(k.k);
        bch2_bkey_buf_reassemble(orig_k, trans->c, k);
 err:
-       bch2_trans_iter_put(trans, iter);
+       bch2_trans_iter_exit(trans, &iter);
        return ret;
 }
 
@@ -2139,6 +2200,7 @@ get_bio:
        /* 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;
@@ -2241,13 +2303,14 @@ out_read_done:
 }
 
 void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
-                struct bvec_iter bvec_iter, u64 inode,
+                struct bvec_iter bvec_iter, subvol_inum inum,
                 struct bch_io_failures *failed, unsigned flags)
 {
        struct btree_trans trans;
-       struct btree_iter *iter;
+       struct btree_iter iter;
        struct bkey_buf sk;
        struct bkey_s_c k;
+       u32 snapshot;
        int ret;
 
        BUG_ON(flags & BCH_READ_NODECODE);
@@ -2256,23 +2319,37 @@ void __bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
        bch2_trans_init(&trans, c, 0, 0);
 retry:
        bch2_trans_begin(&trans);
+       iter = (struct btree_iter) { NULL };
+
+       ret = bch2_subvolume_get_snapshot(&trans, inum.subvol, &snapshot);
+       if (ret)
+               goto err;
 
-       iter = bch2_trans_get_iter(&trans, BTREE_ID_extents,
-                                  POS(inode, bvec_iter.bi_sector),
-                                  BTREE_ITER_SLOTS);
+       bch2_trans_iter_init(&trans, &iter, BTREE_ID_extents,
+                            SPOS(inum.inum, bvec_iter.bi_sector, snapshot),
+                            BTREE_ITER_SLOTS|BTREE_ITER_FILTER_SNAPSHOTS);
        while (1) {
                unsigned bytes, sectors, offset_into_extent;
                enum btree_id data_btree = BTREE_ID_extents;
 
-               bch2_btree_iter_set_pos(iter,
-                               POS(inode, bvec_iter.bi_sector));
+               /*
+                * read_extent -> io_time_reset may cause a transaction restart
+                * without returning an error, we need to check for that here:
+                */
+               if (!bch2_trans_relock(&trans)) {
+                       ret = -EINTR;
+                       break;
+               }
 
-               k = bch2_btree_iter_peek_slot(iter);
+               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 -
+               offset_into_extent = iter.pos.offset -
                        bkey_start_offset(k.k);
                sectors = k.k->size - offset_into_extent;
 
@@ -2303,7 +2380,7 @@ retry:
                if (bvec_iter.bi_size == bytes)
                        flags |= BCH_READ_LAST_FRAGMENT;
 
-               ret = __bch2_read_extent(&trans, rbio, bvec_iter, iter->pos,
+               ret = __bch2_read_extent(&trans, rbio, bvec_iter, iter.pos,
                                         data_btree, k,
                                         offset_into_extent, failed, flags);
                if (ret)
@@ -2315,19 +2392,21 @@ retry:
                swap(bvec_iter.bi_size, bytes);
                bio_advance_iter(&rbio->bio, &bvec_iter, bytes);
        }
-       bch2_trans_iter_put(&trans, iter);
+err:
+       bch2_trans_iter_exit(&trans, &iter);
 
        if (ret == -EINTR || ret == READ_RETRY || ret == READ_RETRY_AVOID)
                goto retry;
 
+       bch2_trans_exit(&trans);
+       bch2_bkey_buf_exit(&sk, c);
+
        if (ret) {
-               bch_err_inum_ratelimited(c, inode,
+               bch_err_inum_ratelimited(c, inum.inum,
                                         "read error %i from btree lookup", ret);
                rbio->bio.bi_status = BLK_STS_IOERR;
                bch2_rbio_done(rbio);
        }
-       bch2_trans_exit(&trans);
-       bch2_bkey_buf_exit(&sk, c);
 }
 
 void bch2_fs_io_exit(struct bch_fs *c)