When dax_lock_mapping_entry() has to sleep to obtain entry lock, it will fail to unlock mapping->i_pages spinlock and thus immediately deadlock against itself when retrying to grab the entry lock again. Fix the problem by unlocking mapping->i_pages before retrying.
Fixes: c2a7d2a115525d3501d38e23d24875a79a07e15e Reported-by: Barret Rhoden <[email protected]> Signed-off-by: Jan Kara <[email protected]> --- fs/dax.c | 1 + 1 file changed, 1 insertion(+) Dan, can you please get this merged? Otherwise dax_lock_mapping_entry() deadlocks as soon as there's any contention. diff --git a/fs/dax.c b/fs/dax.c index b68ce484e1be..4becbf168b7f 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -447,6 +447,7 @@ bool dax_lock_mapping_entry(struct page *page) xa_unlock_irq(&mapping->i_pages); break; } else if (IS_ERR(entry)) { + xa_unlock_irq(&mapping->i_pages); WARN_ON_ONCE(PTR_ERR(entry) != -EAGAIN); continue; } -- 2.16.4 _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
