xprtrdma: Reduce required number of send SGEs

The MAX_SEND_SGES check introduced in commit 655fec6987be
("xprtrdma: Use gathered Send for large inline messages") fails
for devices that have a small max_sge.

Instead of checking for a large fixed maximum number of SGEs,
check for a minimum small number. RPC-over-RDMA will switch to
using a Read chunk if an xdr_buf has more pages than can fit in
the device's max_sge limit. This is considerably better than
failing all together to mount the server.

This fix supports devices that have as few as three send SGEs
available.

Reported-by: Selvin Xavier <[email protected]>
Reported-by: Devesh Sharma <[email protected]>
Reported-by: Honggang Li <[email protected]>
Reported-by: Ram Amrani <[email protected]>
Fixes: 655fec6987be ("xprtrdma: Use gathered Send for large ...")
Cc: [email protected] # v4.9+
Tested-by: Honggang Li <[email protected]>
Tested-by: Ram Amrani <[email protected]>
Tested-by: Steve Wise <[email protected]>
Reviewed-by: Parav Pandit <[email protected]>
Signed-off-by: Chuck Lever <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

0 files changed, 0 insertions, 0 deletions