| Message ID | 20220325012959.7039DC340EC@smtp.kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [merged] mm-fs-fix-lru_cache_disabled-race-in-bh_lru.patch removed from -mm tree | expand |
--- a/fs/buffer.c~mm-fs-fix-lru_cache_disabled-race-in-bh_lru +++ a/fs/buffer.c @@ -1235,16 +1235,18 @@ static void bh_lru_install(struct buffer int i; check_irqs_on(); + bh_lru_lock(); + /* * the refcount of buffer_head in bh_lru prevents dropping the * attached page(i.e., try_to_free_buffers) so it could cause * failing page migration. * Skip putting upcoming bh into bh_lru until migration is done. */ - if (lru_cache_disabled()) + if (lru_cache_disabled()) { + bh_lru_unlock(); return; - - bh_lru_lock(); + } b = this_cpu_ptr(&bh_lrus); for (i = 0; i < BH_LRU_SIZE; i++) {
The patch titled Subject: mm: fs: fix lru_cache_disabled race in bh_lru has been removed from the -mm tree. Its filename was mm-fs-fix-lru_cache_disabled-race-in-bh_lru.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Minchan Kim <minchan@kernel.org> Subject: mm: fs: fix lru_cache_disabled race in bh_lru Check lru_cache_disabled under bh_lru_lock. Otherwise, it could introduce race below and it fails to migrate pages containing buffer_head. CPU 0 CPU 1 bh_lru_install lru_cache_disable lru_cache_disabled = false atomic_inc(&lru_disable_count); invalidate_bh_lrus_cpu of CPU 0 bh_lru_lock __invalidate_bh_lrus bh_lru_unlock bh_lru_lock install the bh bh_lru_unlock WHen this race happens a CMA allocation fails, which is critical for the workload which depends on CMA. Link: https://lkml.kernel.org/r/20220308180709.2017638-1-minchan@kernel.org Fixes: 8cc621d2f45d ("mm: fs: invalidate BH LRU during page migration") Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Chris Goldsworthy <cgoldswo@codeaurora.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: John Dias <joaodias@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- fs/buffer.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)