We now alwasy have a per-PD local_dma_lkey available. Make use of that
fact in svc_rdma and stop registering our own MR.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
To support the server-side of an NFSv4.1 backchannel on RDMA
connections, add a transport class that enables backward
direction messages on an existing forward channel connection.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
- "Checksum offload support in user space" enablement
- Misc cxgb4 fixes, add T6 support
- Misc usnic fixes
- 32 bit build warning fixes
- Misc ocrdma fixes
- Multicast loopback prevention extension
- Extend the GID cache to store and return attributes of GIDs
- Misc iSER updates
- iSER clustering update
- Network NameSpace support for rdma CM
- Work Request cleanup series
- New Memory Registration API
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=bBIY
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Pull rdma updates from Doug Ledford:
"This is my initial round of 4.4 merge window patches. There are a few
other things I wish to get in for 4.4 that aren't in this pull, as
this represents what has gone through merge/build/run testing and not
what is the last few items for which testing is not yet complete.
- "Checksum offload support in user space" enablement
- Misc cxgb4 fixes, add T6 support
- Misc usnic fixes
- 32 bit build warning fixes
- Misc ocrdma fixes
- Multicast loopback prevention extension
- Extend the GID cache to store and return attributes of GIDs
- Misc iSER updates
- iSER clustering update
- Network NameSpace support for rdma CM
- Work Request cleanup series
- New Memory Registration API"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (76 commits)
IB/core, cma: Make __attribute_const__ declarations sparse-friendly
IB/core: Remove old fast registration API
IB/ipath: Remove fast registration from the code
IB/hfi1: Remove fast registration from the code
RDMA/nes: Remove old FRWR API
IB/qib: Remove old FRWR API
iw_cxgb4: Remove old FRWR API
RDMA/cxgb3: Remove old FRWR API
RDMA/ocrdma: Remove old FRWR API
IB/mlx4: Remove old FRWR API support
IB/mlx5: Remove old FRWR API support
IB/srp: Dont allocate a page vector when using fast_reg
IB/srp: Remove srp_finish_mapping
IB/srp: Convert to new registration API
IB/srp: Split srp_map_sg
RDS/IW: Convert to new memory registration API
svcrdma: Port to new memory registration API
xprtrdma: Port to new memory registration API
iser-target: Port to new memory registration API
IB/iser: Port to new fast registration API
...
Instead of maintaining a fastreg page list, keep an sg table
and convert an array of pages to a sg list. Then call ib_map_mr_sg
and construct ib_reg_wr.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Selvin Xavier <selvin.xavier@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Now that the NFS server advertises a maximum payload size of 1MB
for RPC/RDMA again, it crashes in svc_process_common() when NFS
client sends a 1MB NFS WRITE on an NFS/RDMA mount.
The server has set up a 259 element array of struct page pointers
in rq_pages[] for each incoming request. The last element of the
array is NULL.
When an incoming request has been completely received,
rdma_read_complete() attempts to set the starting page of the
incoming page vector:
rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];
and the page to use for the reply:
rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
But the value of page_no has already accounted for head->hdr_count.
Thus rq_respages now points past the end of the incoming pages.
For NFS WRITE operations smaller than the maximum, this is harmless.
But when the NFS WRITE operation is as large as the server's max
payload size, rq_respages now points at the last entry in rq_pages,
which is NULL.
Fixes: cc9a903d91 ('svcrdma: Change maximum server payload . . .')
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=270
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Shirley Ma <shirley.ma@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This patch split up struct ib_send_wr so that all non-trivial verbs
use their own structure which embedds struct ib_send_wr. This dramaticly
shrinks the size of a WR for most common operations:
sizeof(struct ib_send_wr) (old): 96
sizeof(struct ib_send_wr): 48
sizeof(struct ib_rdma_wr): 64
sizeof(struct ib_atomic_wr): 96
sizeof(struct ib_ud_wr): 88
sizeof(struct ib_fast_reg_wr): 88
sizeof(struct ib_bind_mw_wr): 96
sizeof(struct ib_sig_handover_wr): 80
And with Sagi's pending MR rework the fast registration WR will also be
down to a reasonable size:
sizeof(struct ib_fastreg_wr): 64
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> [srp, srpt]
Reviewed-by: Chuck Lever <chuck.lever@oracle.com> [sunrpc]
Tested-by: Haggai Eran <haggaie@mellanox.com>
Tested-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
The server rdma_read_chunk_lcl() and rdma_read_chunk_frmr() functions
were not taking into account the initial page_offset when determining
the rdma read length. This resulted in a read who's starting address
and length exceeded the base/bounds of the frmr.
The server gets an async error from the rdma device and kills the
connection, and the client then reconnects and resends. This repeats
indefinitely, and the application hangs.
Most work loads don't tickle this bug apparently, but one test hit it
every time: building the linux kernel on a 16 core node with 'make -j
16 O=/mnt/0' where /mnt/0 is a ramdisk mounted via NFSRDMA.
This bug seems to only be tripped with devices having small fastreg page
list depths. I didn't see it with mlx4, for instance.
Fixes: 0bf4828983 ('svcrdma: refactor marshalling logic')
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd updates from Bruce Fields:
"A relatively quiet cycle, with a mix of cleanup and smaller bugfixes"
* 'for-4.2' of git://linux-nfs.org/~bfields/linux: (24 commits)
sunrpc: use sg_init_one() in krb5_rc4_setup_enc/seq_key()
nfsd: wrap too long lines in nfsd4_encode_read
nfsd: fput rd_file from XDR encode context
nfsd: take struct file setup fully into nfs4_preprocess_stateid_op
nfsd: refactor nfs4_preprocess_stateid_op
nfsd: clean up raparams handling
nfsd: use swap() in sort_pacl_range()
rpcrdma: Merge svcrdma and xprtrdma modules into one
svcrdma: Add a separate "max data segs macro for svcrdma
svcrdma: Replace GFP_KERNEL in a loop with GFP_NOFAIL
svcrdma: Keep rpcrdma_msg fields in network byte-order
svcrdma: Fix byte-swapping in svc_rdma_sendto.c
nfsd: Update callback sequnce id only CB_SEQUENCE success
nfsd: Reset cb_status in nfsd4_cb_prepare() at retrying
svcrdma: Remove svc_rdma_xdr_decode_deferred_req()
SUNRPC: Move EXPORT_SYMBOL for svc_process
uapi/nfs: Add NFSv4.1 ACL definitions
nfsd: Remove dead declarations
nfsd: work around a gcc-5.1 warning
nfsd: Checking for acl support does not require fetching any acls
...
Fields in struct rpcrdma_msg are __be32. Don't byte-swap these
fields when decoding RPC calls and then swap them back for the
reply. For the most part, they can be left alone.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Introduce helper rdma_cap_read_multi_sge() to help us check if the port of an
IB device support RDMA Read Multiple Scatter-Gather Entries.
Signed-off-by: Michael Wang <yun.wang@profitbricks.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Use raw management helpers to reform IB-ulp xprtrdma.
Signed-off-by: Michael Wang <yun.wang@profitbricks.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Most NFS RPCs place their large payload argument at the end of the
RPC header (eg, NFSv3 WRITE). For NFSv3 WRITE and SYMLINK, RPC/RDMA
sends the complete RPC header inline, and the payload argument in
the read list. Data in the read list is the last part of the XDR
stream.
One important case is not like this, however. NFSv4 COMPOUND is a
counted array of operations. A WRITE operation, with its large data
payload, can appear in the middle of the compound's operations
array. Thus NFSv4 WRITE compounds can have header content after the
WRITE payload.
The Linux client, for example, performs an NFSv4 WRITE like this:
{ PUTFH, WRITE, GETATTR }
Though RFC 5667 is not precise about this, the proper way to convey
this compound is to place the GETATTR inline, _after_ the front of
the RPC header. The receiver inserts the read list payload into the
XDR stream after the initial WRITE arguments, and before the GETATTR
operation, thanks to the value of the read list "position" field.
The Linux client currently sends the GETATTR at the end of the
RPC/RDMA read list, which is incorrect. It will be corrected in the
future.
The Linux server currently rejects NFSv4 compounds with inline
content after the read list. For the above NFSv4 WRITE compound, the
NFS compound header indicates there are three operations, but the
server finds nonsense when it looks in the XDR stream for the third
operation, and the compound fails with OP_ILLEGAL.
Move trailing inline content to the end of the XDR buffer's page
list. This presents incoming NFSv4 WRITE compounds to NFSD in the
same way the socket transport does.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This is a pre-requisite for a subsequent patch.
Read list XDR round-up needs to be done _before_ additional inline
content is copied to the end of the XDR buffer's page list. Move
the logic added by commit e560e3b510 ("svcrdma: Add zero padding
if the client doesn't send it").
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently the Linux server can not decode RDMA_NOMSG type requests.
Operations whose length exceeds the fixed size of RDMA SEND buffers,
like large NFSv4 CREATE(NF4LNK) operations, must be conveyed via
RDMA_NOMSG.
For an RDMA_MSG type request, the client sends the RPC/RDMA, RPC
headers, and some or all of the NFS arguments via RDMA SEND.
For an RDMA_NOMSG type request, the client sends just the RPC/RDMA
header via RDMA SEND. The request's read list contains elements for
the entire RPC message, including the RPC header.
NFSD expects the RPC/RMDA header and RPC header to be contiguous in
page zero of the XDR buffer. Add logic in the RDMA READ path to make
the read list contents land where the server prefers, when the
incoming message is a type RDMA_NOMSG message.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
An RPC/RDMA client may send large RPC arguments via a read
list. This is a list of scatter/gather elements which convey
RPC call arguments too large to fit in a small RDMA SEND.
Each entry in the read list has a "position" field, whose value is
the byte offset in the XDR stream where the data in that entry is to
be inserted. Entries which share the same "position" value make up
the same RPC argument. The receiver inserts entries with the same
position field value in list order into the XDR stream.
Currently the Linux NFS/RDMA server cannot handle receiving read
chunks in more than one position, mostly because no current client
sends read lists with elements in more than one position. As a
sanity check, ensure that all received chunks have the same
"rc_position."
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The RDMA reader function doesn't change once an svcxprt_rdma is
instantiated. Instead of checking sc_devcap during every incoming
RPC, set the reader function once when the connection is accepted.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Current convention is to avoid using BUG_ON() in places where an
oops could cause complete system failure.
Replace BUG_ON() call sites in svcrdma with an assertion error
message and allow execution to continue safely.
Some BUG_ON() calls are removed because they have never fired in
production (that we are aware of).
Some WARN_ON() calls are also replaced where a back trace is not
helpful; e.g., in a workqueue task.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The byte_count argument is not used, and the function is called
only from one place.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Nit: Fix inconsistent white space in dprintk messages.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
See RFC 5666 section 3.7: clients don't have to send zero XDR
padding.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=246
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Fencing forces the invalidate to only happen after all prior send
work requests have been completed.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reported by : Devesh Sharma <Devesh.Sharma@Emulex.Com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This patch refactors the NFSRDMA server marshalling logic to
remove the intermediary map structures. It also fixes an existing bug
where the NFSRDMA server was not minding the device fast register page
list length limitations.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
The server regression was caused by the addition of rq_next_page
(afc59400d6). There were a few places that
were missed with the update of the rq_respages array.
Signed-off-by: Tom Tucker <tom@ogc.us>
Tested-by: Steve Wise <swise@ogc.us>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The svcrdma transport was un-marshalling requests in-place. This resulted
in sparse warnings due to __beXX data containing both NBO and HBO data.
The code has been restructured to do byte-swapping as the header is
parsed instead of when the header is validated immediately after receipt.
Also moved extern declarations for the workqueue and memory pools to the
private header file.
Signed-off-by: Tom Tucker <tom@ogc.us>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There are several error paths in the code that do not unmap DMA. This
patch adds calls to svc_rdma_unmap_dma to free these DMA contexts.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There was logic in the send path that assumed that a page containing data
to send to the client has a KVA. This is not always the case and can result
in data corruption when page_address returns zero and we end up DMA mapping
zero.
This patch changes the bus mapping logic to avoid page_address() where
necessary and converts all calls from ib_dma_map_single to ib_dma_map_page
in order to keep the map/unmap calls symmetric.
Signed-off-by: Tom Tucker <tom@ogc.us>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
svc_xprt_received must be called when ->xpo_recvfrom has finished
receiving a message, so that the XPT_BUSY flag will be cleared and
if necessary, requeued for further work.
This call is currently made in each ->xpo_recvfrom function, often
from multiple different points. In each case it is the earliest point
on a particular path where it is known that the protection provided by
XPT_BUSY is no longer needed.
However there are (still) some error paths which do not call
svc_xprt_received, and requiring each ->xpo_recvfrom to make the call
does not encourage robustness.
So: move the svc_xprt_received call to be made just after the
call to ->xpo_recvfrom(), and move it of the various ->xpo_recvfrom
methods.
This means that it may not be called at the earliest possible instant,
but this is unlikely to be a measurable performance issue.
Note that there are still other calls to svc_xprt_received as it is
also needed when an xprt is newly created.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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>
In case the check on ch_count fails the cleanup path is skipped and the
previously allocated memory 'rpl_map', 'chl_map' is not freed.
Reported by Coverity.
Signed-off-by: Christian Engelmayer <christian.engelmayer@frequentis.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The nfs server rdma transport was mapping rdma read target pages for
TO_DEVICE instead of FROM_DEVICE. This causes data corruption on non
cache-coherent systems if frmrs are used.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
RPCRDMA requests that specify a read-list are fetched with RDMA_READ. Using
an FRMR to map the data sink improves NFSRDMA security on transports that
place the RDMA_READ data sink LKEY on the wire because the valid lifetime
of the MR is only the duration of the RDMA_READ. The LKEY is invalidated
when the last RDMA_READ WR completes.
Mapping the data sink also allows for very large amounts to data to be
fetched with a single WR, so if the client is also using FRMR, the entire
RPC read-list can be fetched with a single WR.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
RDMA_READ completions are kept on a separate queue from the general
I/O request queue. Since a separate lock is used to protect the RDMA_READ
completion queue, a race exists between the dto_tasklet and the
svc_rdma_recvfrom thread where the dto_tasklet sets the XPT_DATA
bit and adds I/O to the read-completion queue. Concurrently, the
recvfrom thread checks the generic queue, finds it empty and resets
the XPT_DATA bit. A subsequent svc_xprt_enqueue will fail to enqueue
the transport for I/O and cause the transport to "stall".
The fix is to protect both lists with the same lock and set the XPT_DATA
bit with this lock held.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Add a dma map count in order to verify that all DMA mapping resources
have been freed when the transport is closed.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Modify the RDMA_READ processing to use the reply and chunk list mapping data
types. Also add a special purpose 'hdr_count' field in in the context to hold
the header page count instead of overloading the SGE length field and
corrupting the DMA map length.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
A RDMA read-list cannot contain more elements than RPCSVC_MAXPAGES or
it will overflow the DTO context. Verify this when processing the
protocol header.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
The svc_rdma_send_error function is called when an RPCRDMA protocol
error is detected. This function attempts to post an error reply message.
Since an error posting to a transport in error is ignored, change
the return type to void.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
The rdma_read_complete function needs to copy the rqstp transport address
from the transport. Failure to do so can result in using the wrong
authentication method for the RPC or bug checking if the rqstp address
is not valid.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
An NFS_WRITE requires a set of RDMA_READ requests to fetch the write
data from the client. There are two principal pieces of data that
need to be tracked: the list of pages that comprise the completed RPC
and the SGE of dma mapped pages to refer to this list of pages. Previously
this whole bit was managed as a linked list of contexts with the
context containing the page list buried in this list. This patch
simplifies this processing by not keeping a linked list, but rather only
a pionter from the last submitted RDMA_READ's context to the context
that maps the set of pages that describe the RPC. This significantly
simplifies this code path. SGE contexts are cleaned up inline in the DTO
path instead of at read completion time.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
The rdma_read_xdr function did not discriminate between no read-list and
an error posting the read-list. This results in a leak of a page if there
is an error posting the read-list.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
The svcrdma transport provider currently allocates receive buffers
to the RQ through the xpo_release_rqst method. This approach is overly
complicated since it means that the rqstp rq_xprt_ctxt has to be
selectively set based on whether the RPC is going to be processed
immediately or deferred. Instead, just post the receive buffer when
we are certain that we are replying in the send_reply function.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
The RDMACTXT_F_LAST_CTXT bit was getting set incorrectly
when the last chunk in the read-list spanned multiple pages. This
resulted in a kernel panic when the wrong context was used to
build the RPC iovec page list.
RDMA_READ is used to fetch RPC data from the client for
NFS_WRITE requests. A scatter-gather is used to map the
advertised client side buffer to the server-side iovec and
associated page list.
WR contexts are used to convey which scatter-gather entries are
handled by each WR. When the write data is large, a single RPC may
require multiple RDMA_READ requests so the contexts for a single RPC
are chained together in a linked list. The last context in this list
is marked with a bit RDMACTXT_F_LAST_CTXT so that when this WR completes,
the CQ handler code can enqueue the RPC for processing.
The code in rdma_read_xdr was setting this bit on the last two
contexts on this list when the last read-list chunk spanned multiple
pages. This caused the svc_rdma_recvfrom logic to incorrectly build
the RPC and caused the kernel to crash because the second-to-last
context doesn't contain the iovec page list.
Modified the condition that sets this bit so that it correctly detects
the last context for the RPC.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Tested-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The iWARP protocol limits RDMA read requests to a single scatter
entry. NFS/RDMA has code in rdma_read_max_sge() that is supposed to
limit the sge_count for RDMA read requests to 1, but the code to do
that is inside an #ifdef RDMA_TRANSPORT_IWARP block. In the mainline
kernel at least, RDMA_TRANSPORT_IWARP is an enum and not a
preprocessor #define, so the #ifdef'ed code is never compiled.
In my test of a kernel build with -j8 on an NFS/RDMA mount, this
problem eventually leads to trouble starting with:
svcrdma: Error posting send = -22
svcrdma : RDMA_READ error = -22
and things go downhill from there.
The trivial fix is to delete the #ifdef guard. The check seems to be
a remnant of when the NFS/RDMA code was not merged and needed to
compile against multiple kernel versions, although I don't think it
ever worked as intended. In any case now that the code is upstream
there's no need to test whether the RDMA_TRANSPORT_IWARP constant is
defined or not.
Without this patch, my kernel build on an NFS/RDMA mount using NetEffect
adapters quickly and 100% reproducibly failed with an error like:
ld: final link failed: Software caused connection abort
With the patch applied I was able to complete a kernel build on the
same setup.
(Tom Tucker says this is "actually an _ancient_ remnant when it had to
compile against iWARP vs. non-iWARP enabled OFA trees.")
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file implements the RDMA transport recvfrom function. The function
dequeues work reqeust completion contexts from an I/O list that it shares
with the I/O tasklet in svc_rdma_transport.c. For ONCRPC RDMA, an RPC may
not be complete when it is received. Instead, the RDMA header that precedes
the RPC message informs the transport where to get the RPC data from on
the client and where to place it in the RPC message before it is delivered
to the server. The svc_rdma_recvfrom function therefore, parses this RDMA
header and issues any necessary RDMA operations to fetch the remainder of
the RPC from the client.
Special handling is required when the request involves an RDMA_READ.
In this case, recvfrom submits the RDMA_READ requests to the underlying
transport driver and then returns 0. When the transport
completes the last RDMA_READ for the request, it enqueues it on a
read completion queue and enqueues the transport. The recvfrom code
favors this queue over the regular DTO queue when satisfying reads.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
