bcachefs: Fix bch2_alloc_sectors_start_trans() error handling

When we fail to allocate because of insufficient open buckets, we don't
want to retry from the full set of devices - we just want to retry in
blocking mode.

But if the retry in blocking mode fails with a different error code, we
end up squashing the -BCH_ERR_open_buckets_empty error with an error
that makes us thing we won't be able to allocate (insufficient_devices)
- which is incorrect when we didn't try to allocate from the full set of
devices, and causes the write to fail.

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

diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c
index 1ba0eeb7552a2795d033d2603cccce611c8f3381..0e615798260721c3f84a0e217a0105fbdcd2b198 100644 (file)
--- a/fs/bcachefs/alloc_foreground.c
+++ b/fs/bcachefs/alloc_foreground.c
@@ -1374,8 +1374,17 @@ retry:
                        goto alloc_done;
 
                /* Don't retry from all devices if we're out of open buckets: */
-               if (bch2_err_matches(ret, BCH_ERR_open_buckets_empty))
-                       goto allocate_blocking;
+               if (bch2_err_matches(ret, BCH_ERR_open_buckets_empty)) {
+                       int ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
+                                             target, erasure_code,
+                                             nr_replicas, &nr_effective,
+                                             &have_cache, watermark,
+                                             flags, cl);
+                       if (!ret ||
+                           bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
+                           bch2_err_matches(ret, BCH_ERR_open_buckets_empty))
+                               goto alloc_done;
+               }
 
                /*
                 * Only try to allocate cache (durability = 0 devices) from the
@@ -1389,7 +1398,6 @@ retry:
                                              &have_cache, watermark,
                                              flags, cl);
        } else {
-allocate_blocking:
                ret = open_bucket_add_buckets(trans, &ptrs, wp, devs_have,
                                              target, erasure_code,
                                              nr_replicas, &nr_effective,