bcachefs: fiemap: Fix a lockdep splat

As with the previous patch, we generally can't hold btree locks while
copying to userspace, as that may incur a page fault and require
mmap_lock.

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

diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index f417889eba08b38884bc2f7c0b97bce094bd0a35..9280f514bc9f52e3ec873c5231eab6bcc33146a8 100644 (file)
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -943,6 +943,7 @@ retry:
                cur.k->k.p.offset += cur.k->k.size;
 
                if (have_extent) {
+                       bch2_trans_unlock(&trans);
                        ret = bch2_fill_extent(c, info,
                                        bkey_i_to_s_c(prev.k), 0);
                        if (ret)
@@ -961,9 +962,11 @@ err:
        if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
                goto retry;
 
-       if (!ret && have_extent)
+       if (!ret && have_extent) {
+               bch2_trans_unlock(&trans);
                ret = bch2_fill_extent(c, info, bkey_i_to_s_c(prev.k),
                                       FIEMAP_EXTENT_LAST);
+       }
 
        bch2_trans_exit(&trans);
        bch2_bkey_buf_exit(&cur, c);