shrink_dcache_parent may spin waiting for a parallel shrink_dentry_list. In this case we may have 0 dentries to dispose, so we will never schedule out while waiting for the parallel shrink_dentry_list to complete.
Tested that this fixes syzbot reports of stalls in shrink_dcache_parent()
Fixes: 32785c0539b7 ("fs/dcache.c: add cond_resched() in shrink_dentry_list()")
Reported-by: [email protected]
Cc: Nikolay Borisov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Goldwyn Rodrigues <[email protected]>
Cc: Jeff Mahoney <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Linus Torvalds <[email protected]>
Signed-off-by: Khazhismel Kumykov <[email protected]>
---
fs/dcache.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/dcache.c b/fs/dcache.c
index 591b34500e41..3507badeb60a 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1489,6 +1489,7 @@ void shrink_dcache_parent(struct dentry *parent)
break;
shrink_dentry_list(&data.dispose);
+ cond_resched();
}
}
EXPORT_SYMBOL(shrink_dcache_parent);
--
2.17.0.484.g0c8726318c-goog
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