Commit Graph

41 Commits

Author SHA1 Message Date
Avinash Repaka f9fb69adb6 RDS: make message size limit compliant with spec
RDS support max message size as 1M but the code doesn't check this
in all cases. Patch fixes it for RDMA & non-RDMA and RDS MR size
and its enforced irrespective of underlying transport.

Signed-off-by: Avinash Repaka <avinash.repaka@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2017-01-02 14:02:57 -08:00
Santosh Shilimkar 941f8d55f6 RDS: RDMA: Fix the composite message user notification
When application sends an RDS RDMA composite message consist of
RDMA transfer to be followed up by non RDMA payload, it expect to
be notified *only* when the full message gets delivered. RDS RDMA
notification doesn't behave this way though.

Thanks to Venkat for debug and root casuing the issue
where only first part of the message(RDMA) was
successfully delivered but remainder payload delivery failed.
In that case, application should not be notified with
a false positive of message delivery success.

Fix this case by making sure the user gets notified only after
the full message delivery.

Reviewed-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2017-01-02 14:02:54 -08:00
Santosh Shilimkar c536a06887 RDS: RDMA: silence the use_once mr log flood
In absence of extension headers, message log will keep
flooding the console. As such even without use_once we can
clean up the MRs so its not really an error case message
so make it debug message

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
2017-01-02 14:02:49 -08:00
Geliang Tang a763f78cea RDS: use rb_entry()
To make the code clearer, use rb_entry() instead of container_of() to
deal with rbtree.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-20 14:22:49 -05:00
santosh.shilimkar@oracle.com 3f6b314303 RDS: Fix rds MR reference count in rds_rdma_unuse()
rds_rdma_unuse() drops the mr reference count which it hasn't
taken. Correct way of removing mr is to remove mr from the tree
and then rdma_destroy_mr() it first, then rds_mr_put() to decrement
its reference count. Whichever thread holds last reference will free
the mr via rds_mr_put()

This bug was triggering weird null pointer crashes. One if the trace
for it is captured below.

BUG: unable to handle kernel NULL pointer dereference at
0000000000000104
IP: [<ffffffffa0899471>] rds_ib_free_mr+0x31/0x130 [rds_rdma]
PGD 4366fa067 PUD 4366f9067 PMD 0
Oops: 0000 [#1] SMP

[...]

task: ffff88046da6a000 ti: ffff88046da6c000 task.ti: ffff88046da6c000
RIP: 0010:[<ffffffffa0899471>]  [<ffffffffa0899471>]
rds_ib_free_mr+0x31/0x130 [rds_rdma]
RSP: 0018:ffff88046fa43bd8  EFLAGS: 00010286
RAX: 0000000071d38b80 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff880079e7ff40
RBP: ffff88046fa43bf8 R08: 0000000000000000 R09: 0000000000000000
R10: ffff88046fa43ca8 R11: ffff88046a802ed8 R12: ffff880079e7fa40
R13: 0000000000000000 R14: ffff880079e7ff40 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88046fa40000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000104 CR3: 00000004366fb000 CR4: 00000000000006e0
Stack:
 ffff880079e7fa40 ffff880671d38f08 ffff880079e7ff40 0000000000000296
 ffff88046fa43c28 ffffffffa087a38b ffff880079e7fa40 ffff880671d38f10
 0000000000000000 0000000000000292 ffff88046fa43c48 ffffffffa087a3b6
Call Trace:
 <IRQ>
 [<ffffffffa087a38b>] rds_destroy_mr+0x8b/0xa0 [rds]
 [<ffffffffa087a3b6>] __rds_put_mr_final+0x16/0x30 [rds]
 [<ffffffffa087a492>] rds_rdma_unuse+0xc2/0x120 [rds]
 [<ffffffffa08766d3>] rds_recv_incoming_exthdrs+0x83/0xa0 [rds]
 [<ffffffffa0876782>] rds_recv_incoming+0x92/0x200 [rds]
 [<ffffffffa0895269>] rds_ib_process_recv+0x259/0x320 [rds_rdma]
 [<ffffffffa08962a8>] rds_ib_recv_tasklet_fn+0x1a8/0x490 [rds_rdma]
 [<ffffffff810dcd78>] ? __remove_hrtimer+0x58/0x90
 [<ffffffff810799e1>] tasklet_action+0xb1/0xc0
 [<ffffffff81079b52>] __do_softirq+0xe2/0x290
 [<ffffffff81079df6>] irq_exit+0xa6/0xb0
 [<ffffffff81613915>] do_IRQ+0x65/0xf0
 [<ffffffff816118ab>] common_interrupt+0x6b/0x6b

Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25 16:28:10 -07:00
santosh.shilimkar@oracle.com 5c240fa2ab RDS: Fix assertion level from fatal to warning
Fix the asserion level since its not fatal and can be hit
in normal execution paths. There is no need to take the
system down.

We keep the WARN_ON() to detect the condition if we get
here with bad pages.

Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25 13:35:31 -07:00
santosh.shilimkar@oracle.com 1d2e3f396c RDS: restore return value in rds_cmsg_rdma_args()
In rds_cmsg_rdma_args() 'ret' is used by rds_pin_pages() which returns
number of pinned pages on success. And the same value is returned to the
caller of rds_cmsg_rdma_args() on success which is not intended.

Commit f4a3fc03c1 ("RDS: Clean up error handling in rds_cmsg_rdma_args")
removed the 'ret = 0' line which broke RDS RDMA mode.

Fix it by restoring the return value on rds_pin_pages() success
keeping the clean-up in place.

Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25 13:35:29 -07:00
Cong Wang dee49f203a rds: avoid calling sock_kfree_s() on allocation failure
It is okay to free a NULL pointer but not okay to mischarge the socket optmem
accounting. Compile test only.

Reported-by: rucsoftsec@gmail.com
Cc: Chien Yen <chien.yen@oracle.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-14 17:00:19 -04:00
Dan Rosenberg 218854af84 rds: Integer overflow in RDS cmsg handling
In rds_cmsg_rdma_args(), the user-provided args->nr_local value is
restricted to less than UINT_MAX.  This seems to need a tighter upper
bound, since the calculation of total iov_size can overflow, resulting
in a small sock_kmalloc() allocation.  This would probably just result
in walking off the heap and crashing when calling rds_rdma_pages() with
a high count value.  If it somehow doesn't crash here, then memory
corruption could occur soon after.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-17 12:20:52 -08:00
Andy Grover d139ff0907 RDS: Let rds_message_alloc_sgs() return NULL
Even with the previous fix, we still are reading the iovecs once
to determine SGs needed, and then again later on. Preallocating
space for sg lists as part of rds_message seemed like a good idea
but it might be better to not do this. While working to redo that
code, this patch attempts to protect against userspace rewriting
the rds_iovec array between the first and second accesses.

The consequences of this would be either a too-small or too-large
sg list array. Too large is not an issue. This patch changes all
callers of message_alloc_sgs to handle running out of preallocated
sgs, and fail gracefully.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-30 16:34:18 -07:00
Andy Grover fc8162e3c0 RDS: Copy rds_iovecs into kernel memory instead of rereading from userspace
Change rds_rdma_pages to take a passed-in rds_iovec array instead
of doing copy_from_user itself.

Change rds_cmsg_rdma_args to copy rds_iovec array once only. This
eliminates the possibility of userspace changing it after our
sanity checks.

Implement stack-based storage for small numbers of iovecs, based
on net/socket.c, to save an alloc in the extremely common case.

Although this patch reduces iovec copies in cmsg_rdma_args to 1,
we still do another one in rds_rdma_extra_size. Getting rid of
that one will be trickier, so it'll be a separate patch.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-30 16:34:17 -07:00
Andy Grover f4a3fc03c1 RDS: Clean up error handling in rds_cmsg_rdma_args
We don't need to set ret = 0 at the end -- it's initialized to 0.

Also, don't increment s_send_rdma stat if we're exiting with an
error.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-30 16:34:17 -07:00
Andy Grover a09f69c49b RDS: Return -EINVAL if rds_rdma_pages returns an error
rds_cmsg_rdma_args would still return success even if rds_rdma_pages
returned an error (or overflowed).

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-30 16:34:16 -07:00
Linus Torvalds 1b1f693d7a net: fix rds_iovec page count overflow
As reported by Thomas Pollet, the rdma page counting can overflow.  We
get the rdma sizes in 64-bit unsigned entities, but then limit it to
UINT_MAX bytes and shift them down to pages (so with a possible "+1" for
an unaligned address).

So each individual page count fits comfortably in an 'unsigned int' (not
even close to overflowing into signed), but as they are added up, they
might end up resulting in a signed return value. Which would be wrong.

Catch the case of tot_pages turning negative, and return the appropriate
error code.

Reported-by: Thomas Pollet <thomas.pollet@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-30 16:34:16 -07:00
Dan Carpenter 9b9d2e00bf rds: signedness bug
In the original code if the copy_from_user() fails in rds_rdma_pages()
then the error handling fails and we get a stack trace from kmalloc().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-19 11:59:43 -07:00
Andy Grover 20c72bd5f5 RDS: Implement masked atomic operations
Add two CMSGs for masked versions of cswp and fadd. args
struct modified to use a union for different atomic op type's
arguments. Change IB to do masked atomic ops. Atomic op type
in rds_message similarly unionized.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:16:51 -07:00
Andy Grover 2c3a5f9abb RDS: Add flag for silent ops. Do atomic op before RDMA
Add a flag to the API so users can indicate they want
silent operations. This is needed because silent ops
cannot be used with USE_ONCE MRs, so we can't just
assume silent.

Also, change send_xmit to do atomic op before rdma op if
both are present, and centralize the hairy logic to determine if
we want to attempt silent, or not.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:12:06 -07:00
Andy Grover 7e3bd65ebf RDS: Move some variables around for consistency
Also, add a comment.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:12:05 -07:00
Andy Grover f8b3aaf2ba RDS: Remove struct rds_rdma_op
A big changeset, but it's all pretty dumb.

struct rds_rdma_op was already embedded in struct rm_rdma_op.
Remove rds_rdma_op and put its members in rm_rdma_op. Rename
members with "op_" prefix instead of "r_", for consistency.

Of course this breaks a lot, so fixup the code accordingly.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:58 -07:00
Andy Grover d0ab25a83c RDS: purge atomic resources too in rds_message_purge()
Add atomic_free_op function, analogous to rdma_free_op,
and call it in rds_message_purge().

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:57 -07:00
Andy Grover 4324879df0 RDS: Inline rdma_prepare into cmsg_rdma_args
cmsg_rdma_args just calls rdma_prepare and does a little
arg checking -- not quite enough to justify its existence.
Plus, it is the only caller of rdma_prepare().

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:56 -07:00
Andy Grover 6200ed7799 RDS: Whitespace
Tidy up some whitespace issues.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:44 -07:00
Andy Grover d22faec22c RDS: Do not mask address when pinning pages
This does not appear to be necessary.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:43 -07:00
Andy Grover 40589e74f7 RDS: Base init_depth and responder_resources on hw values
Instead of using a constant for initiator_depth and
responder_resources, read the per-QP values when the
device is enumerated, and then use these values when creating
the connection.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:42 -07:00
Andy Grover 15133f6e67 RDS: Implement atomic operations
Implement a CMSG-based interface to do FADD and CSWP ops.

Alter send routines to handle atomic ops.

Add atomic counters to stats.

Add xmit_atomic() to struct rds_transport

Inline rds_ib_send_unmap_rdma into unmap_rm

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:41 -07:00
Andy Grover f4dd96f7b2 RDS: make sure all sgs alloced are initialized
rds_message_alloc_sgs() now returns correctly-initialized
sg lists, so calleds need not do this themselves.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:39 -07:00
Andy Grover ff87e97a9d RDS: make m_rdma_op a member of rds_message
This eliminates a separate memory alloc, although
it is now necessary to add an "r_active" flag, since
it is no longer to use the m_rdma_op pointer as an
indicator of if an rdma op is present.

rdma SGs allocated from rm sg pool.

rds_rm_size also gets bigger. It's a little inefficient to
run through CMSGs twice, but it makes later steps a lot smoother.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:38 -07:00
Andy Grover 21f79afa5f RDS: fold rdma.h into rds.h
RDMA is now an intrinsic part of RDS, so it's easier to just have
a single header.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:37 -07:00
Andy Grover 3ef13f3c22 RDS: cleanup/fix rds_rdma_unuse
First, it looks to me like the atomic_inc is wrong.
We should be decrementing refcount only once here, no? It's
already being done by the mr_put() at the end.

Second, simplify the logic a bit by bailing early (with a warning)
if !mr.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:35 -07:00
Andy Grover e779137aa7 RDS: break out rdma and data ops into nested structs in rds_message
Clearly separate rdma-related variables in rm from data-related ones.
This is in anticipation of adding atomic support.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:33 -07:00
Andy Grover 8690bfa17a RDS: cleanup: remove "== NULL"s and "!= NULL"s in ptr comparisons
Favor "if (foo)" style over "if (foo != NULL)".

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:32 -07:00
Tina Yang 35b52c7053 RDS: Fix corrupted rds_mrs
On second look at this bug (OFED #2002), it seems that the
collision is not with the retransmission queue (packet acked
by the peer), but with the local send completion.  A theoretical
sequence of events (from time t0 to t3) is thought to be as
follows,

Thread #1
t0:
    sock_release
    rds_release
    rds_send_drop_to /* wait on send completion */
t2:
    rds_rdma_drop_keys()   /* destroy & free all mrs */

Thread #2
t1:
    rds_ib_send_cq_comp_handler
    rds_ib_send_unmap_rm
    rds_message_unmapped   /* wake up #1 @ t0 */
t3:
    rds_message_put
    rds_message_purge
    rds_mr_put   /* memory corruption detected */

The problem with the rds_rdma_drop_keys() is it could
remove a mr's refcount more than its due (i.e. repeatedly
as long as it still remains in the tree (mr->r_refcount > 0)).
Theoretically it should remove only one reference - reference
by the tree.

        /* Release any MRs associated with this socket */
        while ((node = rb_first(&rs->rs_rdma_keys))) {
                mr = container_of(node, struct rds_mr, r_rb_node);
                if (mr->r_trans == rs->rs_transport)
                        mr->r_invalidate = 0;
                rds_mr_put(mr);
        }

I think the correct way of doing it is to remove the mr from
the tree and rds_destroy_mr it first, then a rds_mr_put()
to decrement its reference count by one.  Whichever thread
holds the last reference will free the mr via rds_mr_put().

Signed-off-by: Tina Yang <tina.yang@oracle.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:07:31 -07:00
Andy Grover 9e2effba2c RDS: Fix BUG_ONs to not fire when in a tasklet
in_interrupt() is true in softirqs. The BUG_ONs are supposed
to check for if irqs are disabled, so we should use
BUG_ON(irqs_disabled()) instead, duh.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:07:31 -07:00
David S. Miller 871039f02f Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/stmmac/stmmac_main.c
	drivers/net/wireless/wl12xx/wl1271_cmd.c
	drivers/net/wireless/wl12xx/wl1271_main.c
	drivers/net/wireless/wl12xx/wl1271_spi.c
	net/core/ethtool.c
	net/mac80211/scan.c
2010-04-11 14:53:53 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Andy Grover 561c7df63e RDS: Do not call set_page_dirty() with irqs off
set_page_dirty() unconditionally re-enables interrupts, so
if we call it with irqs off, they will be on after the call,
and that's bad. This patch moves the call after we've re-enabled
interrupts in send_drop_to(), so it's safe.

Also, add BUG_ONs to let us know if we ever do call set_page_dirty
with interrupts off.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16 21:17:01 -07:00
Joe Perches f64f9e7192 net: Move && and || to end of previous line
Not including net/atm/

Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-29 16:55:45 -08:00
Andy Grover 244546f0d3 RDS: Add GET_MR_FOR_DEST sockopt
RDS currently supports a GET_MR sockopt to establish a
memory region (MR) for a chunk of memory. However, the fastreg
method ties a MR to a particular destination. The GET_MR_FOR_DEST
sockopt allows the remote machine to be specified, and thus
support for fastreg (aka FRWRs).

Note that this patch does *not* do all of this - it simply
implements the new sockopt in terms of the old one, so applications
can begin to use the new sockopt in preparation for cutover to
FRWRs.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30 15:06:37 -07:00
Andy Grover 830eb7d56c RDS: use get_user_pages_fast()
Use the new function that is simpler and faster.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:20 -07:00
Andy Grover 7acd4a794c RDS: Fix ordering in a conditional
Putting the constant first is a supposed "best practice" that actually makes
the code harder to read.

Thanks to Roland Dreier for finding a bug in this "simple, obviously correct"
patch.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09 17:21:18 -07:00
Andy Grover eff5f53bef RDS: RDMA support
Some transports may support RDMA features. This handles the
non-transport-specific parts, like pinning user pages and
tracking mapped regions.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-26 23:39:29 -08:00