RDS doesn't support RDMA on memory apertures that require On Demand Paging (ODP), such as FS DAX memory. User applications can try to use RDS to perform RDMA over such memories and since it doesn't report any failure, it can lead to unexpected issues like memory corruption when a couple of out of sync file system operations like ftruncate etc. are performed.
The patch adds a check so that such an attempt to RDMA to/from memory apertures requiring ODP will fail. A sysctl is added to indicate whether RDMA on ODP memory is supported. Hans Westgaard Ry (1): rds: handle unsupported rdma request to fs dax memory Santosh Shilimkar (1): rds: add sysctl for rds support of On-Demand-Paging net/rds/ib.h | 1 + net/rds/ib_sysctl.c | 8 ++++++++ net/rds/rdma.c | 5 +++-- 3 files changed, 12 insertions(+), 2 deletions(-) -- 1.9.1
