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Commit a72986c5 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Alasdair G Kergon
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dm raid1: keep retrying alloc if mempool_alloc failed 



If the code can't handle allocation failures, use __GFP_NOFAIL so that
in case of memory pressure the allocator will retry indefinitely and
won't return NULL which would cause a crash in the function.

This is still not a correct fix, it may cause a classic deadlock when
memory manager waits for I/O being done and I/O waits for some free memory.
I/O code shouldn't allocate any memory. But in this case it probably
doesn't matter much in practice, people usually do not swap on RAID.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent e54f77dd

drivers/md/dm-region-hash.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -283,7 +283,7 @@ static struct dm_region *__rh_alloc(struct dm_region_hash *rh, region_t region) 




	nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC);

	nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC);

	if (unlikely(!nreg))

	if (unlikely(!nreg))

		nreg = kmalloc(sizeof(*nreg), GFP_NOIO);

		nreg = kmalloc(sizeof(*nreg), GFP_NOIO | __GFP_NOFAIL);





	nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?

	nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?

		      DM_RH_CLEAN : DM_RH_NOSYNC;

		      DM_RH_CLEAN : DM_RH_NOSYNC;