From: Mikulas Patocka 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: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm-region-hash.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6.30/drivers/md/dm-region-hash.c =================================================================== --- linux-2.6.30.orig/drivers/md/dm-region-hash.c +++ linux-2.6.30/drivers/md/dm-region-hash.c @@ -283,7 +283,7 @@ static struct dm_region *__rh_alloc(stru nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC); 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) ? DM_RH_CLEAN : DM_RH_NOSYNC;