pop assert when freeing page after bcachefs shutdownbcachefs-put-folio-assert

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

5 files changed, 19 insertions, 1 deletions

diff --git a/fs/bcachefs/fs-io-buffered.c b/fs/bcachefs/fs-io-buffered.c
index e3a75dcca60c..669f84dbe953 100644
--- a/fs/bcachefs/fs-io-buffered.c
+++ b/fs/bcachefs/fs-io-buffered.c
@@ -140,6 +140,7 @@ static int readpage_bio_extend(struct btree_trans *trans,
 				break;
 			}
 
+			folio_set_bcachefs_warn(folio);
 			folio_put(folio);
 		}
 
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index f1472e9135cc..b6ba6f6c7005 100644
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -45,6 +45,8 @@
 #include <linux/string.h>
 #include <linux/xattr.h>
 
+extern int bcachefs_shutdown;
+
 static struct kmem_cache *bch2_inode_cache;
 
 static void bch2_vfs_inode_init(struct btree_trans *, subvol_inum,
@@ -2380,6 +2382,7 @@ static void bch2_put_super(struct super_block *sb)
 {
 	struct bch_fs *c = sb->s_fs_info;
 
+	bcachefs_shutdown = 1;
 	__bch2_fs_stop(c);
 }
 
@@ -2610,6 +2613,8 @@ err:
 	 * userspace as that causes util-linux to retry the mount RO - which is
 	 * confusing:
 	 */
+
+	bcachefs_shutdown = 0;
 	if (bch2_err_matches(ret, EROFS) && ret != -EROFS)
 		ret = -EIO;
 	return bch2_err_class(ret);
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index e6a21b62dcce..f21463fd43ed 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -111,6 +111,7 @@ enum pageflags {
 	PG_swapbacked,		/* Page is backed by RAM/swap */
 	PG_unevictable,		/* Page is "unevictable"  */
 	PG_dropbehind,		/* drop pages on IO completion */
+	PG_bcachefs_warn,
 #ifdef CONFIG_MMU
 	PG_mlocked,		/* Page is vma mlocked */
 #endif
@@ -667,6 +668,8 @@ FOLIO_TEST_CLEAR_FLAG_FALSE(young)
 FOLIO_FLAG_FALSE(idle)
 #endif
 
+FOLIO_FLAG(bcachefs_warn, FOLIO_HEAD_PAGE)
+
 /*
  * PageReported() is used to track reported free pages within the Buddy
  * allocator. We can use the non-atomic version of the test and set
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 15aae955a10b..aa41fba7ef4a 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -159,7 +159,8 @@ TRACE_DEFINE_ENUM(___GFP_LAST_BIT);
 	DEF_PAGEFLAG_NAME(reclaim),					\
 	DEF_PAGEFLAG_NAME(swapbacked),					\
 	DEF_PAGEFLAG_NAME(unevictable),					\
-	DEF_PAGEFLAG_NAME(dropbehind)					\
+	DEF_PAGEFLAG_NAME(dropbehind),					\
+	DEF_PAGEFLAG_NAME(bcachefs_warn)				\
 IF_HAVE_PG_MLOCK(mlocked)						\
 IF_HAVE_PG_HWPOISON(hwpoison)						\
 IF_HAVE_PG_IDLE(idle)							\
diff --git a/mm/swap.c b/mm/swap.c
index 77b2d5997873..56d23d61c9cb 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -45,6 +45,7 @@
 
 /* How many pages do we try to swap or page in/out together? As a power of 2 */
 int page_cluster;
+int bcachefs_shutdown;
 static const int page_cluster_max = 31;
 
 struct cpu_fbatches {
@@ -106,6 +107,13 @@ void __folio_put(struct folio *folio)
 		return;
 	}
 
+	if (folio_test_bcachefs_warn(folio) && bcachefs_shutdown) {
+		BUG();
+		dump_stack();
+	}
+
+	folio_clear_bcachefs_warn(folio);
+
 	page_cache_release(folio);
 	folio_unqueue_deferred_split(folio);
 	mem_cgroup_uncharge(folio);