bcachefs: Fix 'pointer to invalid device' check

This fixes the device removal tests, which have been failing at random
due to the fact that when we're running the .key_invalid checks in the
write path the key may actually no longer exist - we might be racing
with the keys being deleted.

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

diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index d7f74db..1b25f84 100644 (file)
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -1059,6 +1059,7 @@ void bch2_bkey_ptrs_to_text(struct printbuf *out, struct bch_fs *c,
 
 static int extent_ptr_invalid(const struct bch_fs *c,
                              struct bkey_s_c k,
+                             enum bkey_invalid_flags flags,
                              const struct bch_extent_ptr *ptr,
                              unsigned size_ondisk,
                              bool metadata,
@@ -1071,6 +1072,14 @@ static int extent_ptr_invalid(const struct bch_fs *c,
        struct bch_dev *ca;
 
        if (!bch2_dev_exists2(c, ptr->dev)) {
+               /*
+                * If we're in the write path this key might have already been
+                * overwritten, and we could be seeing a device that doesn't
+                * exist anymore due to racing with device removal:
+                */
+               if (flags & BKEY_INVALID_WRITE)
+                       return 0;
+
                prt_printf(err, "pointer to invalid device (%u)", ptr->dev);
                return -BCH_ERR_invalid_bkey;
        }
@@ -1136,8 +1145,8 @@ int bch2_bkey_ptrs_invalid(const struct bch_fs *c, struct bkey_s_c k,
 
                switch (extent_entry_type(entry)) {
                case BCH_EXTENT_ENTRY_ptr:
-                       ret = extent_ptr_invalid(c, k, &entry->ptr, size_ondisk,
-                                                false, err);
+                       ret = extent_ptr_invalid(c, k, flags, &entry->ptr,
+                                                size_ondisk, false, err);
                        if (ret)
                                return ret;