diff options
Diffstat (limited to 'fs/bcachefs/fs-io-buffered.c')
| -rw-r--r-- | fs/bcachefs/fs-io-buffered.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/fs/bcachefs/fs-io-buffered.c b/fs/bcachefs/fs-io-buffered.c index 19d4599918dc..e3a75dcca60c 100644 --- a/fs/bcachefs/fs-io-buffered.c +++ b/fs/bcachefs/fs-io-buffered.c @@ -225,11 +225,26 @@ static void bchfs_read(struct btree_trans *trans, bch2_read_extent(trans, rbio, iter.pos, data_btree, k, offset_into_extent, flags); - swap(rbio->bio.bi_iter.bi_size, bytes); + /* + * Careful there's a landmine here if bch2_read_extent() ever + * starts returning transaction restarts here. + * + * We've changed rbio->bi_iter.bi_size to be "bytes we can read + * from this extent" with the swap call, and we restore it + * below. That restore needs to come before checking for + * errors. + * + * But unlike __bch2_read(), we use the rbio bvec iter, not one + * on the stack, so we can't do the restore right after the + * bch2_read_extent() call: we don't own that iterator anymore + * if BCH_READ_last_fragment is set, since we may have submitted + * that rbio instead of cloning it. + */ if (flags & BCH_READ_last_fragment) break; + swap(rbio->bio.bi_iter.bi_size, bytes); bio_advance(&rbio->bio, bytes); err: if (ret && |