linux_dsm_epyc7002/net
Chuck Lever 9d11b51ce7 svcrdma: Fix send_reply() scatter/gather set-up
The Linux NFS server returns garbage in the data payload of inline
NFS/RDMA READ replies. These are READs of under 1000 bytes or so
where the client has not provided either a reply chunk or a write
list.

The NFS server delivers the data payload for an NFS READ reply to
the transport in an xdr_buf page list. If the NFS client did not
provide a reply chunk or a write list, send_reply() is supposed to
set up a separate sge for the page containing the READ data, and
another sge for XDR padding if needed, then post all of the sges via
a single SEND Work Request.

The problem is send_reply() does not advance through the xdr_buf
when setting up scatter/gather entries for SEND WR. It always calls
dma_map_xdr with xdr_off set to zero. When there's more than one
sge, dma_map_xdr() sets up the SEND sge's so they all point to the
xdr_buf's head.

The current Linux NFS/RDMA client always provides a reply chunk or
a write list when performing an NFS READ over RDMA. Therefore, it
does not exercise this particular case. The Linux server has never
had to use more than one extra sge for building RPC/RDMA replies
with a Linux client.

However, an NFS/RDMA client _is_ allowed to send small NFS READs
without setting up a write list or reply chunk. The NFS READ reply
fits entirely within the inline reply buffer in this case. This is
perhaps a more efficient way of performing NFS READs that the Linux
NFS/RDMA client may some day adopt.

Fixes: b432e6b3d9 ('svcrdma: Change DMA mapping logic to . . .')
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=285
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-07-20 14:58:47 -04:00
..
6lowpan
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-07-04 19:36:06 -07:00
802
8021q
appletalk
atm
ax25 ax25: Stop using sock->sk_protinfo. 2015-06-28 16:55:44 -07:00
batman-adv
bluetooth bluetooth: fix list handling 2015-07-04 19:11:33 -07:00
bridge bridge: mdb: allow the user to delete mdb entry if there's a querier 2015-07-10 18:18:00 -07:00
caif
can can: replace timestamp as unique skb attribute 2015-07-12 21:13:22 +02:00
ceph libceph: treat sockaddr_storage with uninitialized family as blank 2015-07-09 20:30:34 +03:00
core net: call rcu_read_lock early in process_backlog 2015-07-10 18:16:36 -07:00
dcb
dccp
decnet
dns_resolver
dsa net: dsa: Fix off-by-one in switch address parsing 2015-07-11 23:25:16 -07:00
ethernet
hsr
ieee802154
ipv4 net: inet_diag: always export IPV6_V6ONLY sockopt for listening sockets 2015-07-10 23:25:24 -07:00
ipv6 ipv6: Make MLD packets to only be processed locally 2015-07-03 09:52:38 -07:00
ipx
irda
iucv
key Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-06-24 16:49:49 -07:00
l2tp
lapb
llc
mac80211 Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
mac802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-06-24 16:49:49 -07:00
mpls
netfilter netfilter: nfnetlink: keep going batch handling on missing modules 2015-07-02 17:59:33 +02:00
netlabel
netlink netlink: Delete an unnecessary check before the function call "module_put" 2015-07-03 09:27:43 -07:00
netrom
nfc
openvswitch
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
phonet
rds Changes for 4.2-rc 2015-07-15 17:03:03 -07:00
rfkill
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
rxrpc
sched net: sched: flower fix typo 2015-06-25 05:23:02 -07:00
sctp sctp: Fix race between OOTB responce and route removal 2015-06-29 09:28:42 -07:00
sunrpc svcrdma: Fix send_reply() scatter/gather set-up 2015-07-20 14:58:47 -04:00
switchdev net: switchdev: don't abort unsupported operations 2015-07-11 21:29:55 -07:00
tipc net/tipc: initialize security state for new connection socket 2015-07-08 16:08:23 -07:00
unix
vmw_vsock
wimax
wireless
x25
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-06-24 16:49:49 -07:00
compat.c
Kconfig
Makefile
socket.c
sysctl_net.c