kernel/linux.git/include/linux/sunrpc/svc.h, branch v5.4.185

nfsd: Fix NFSv4 READ on RDMA when using readv

2020-08-11T13:33:42+00:00

commit 412055398b9e67e07347a936fc4a6adddabe9cf4 upstream. svcrdma expects that the payload falls precisely into the xdr_buf page vector. This does not seem to be the case for nfsd4_encode_readv(). This code is called only when fops->splice_read is missing or when RQ_SPLICE_OK is clear, so it's not a noticeable problem in many common cases. Add new transport method: ->xpo_read_payload so that when a READ payload does not fit exactly in rq_res's page vector, the XDR encoder can inform the RPC transport exactly where that payload is, without the payload's XDR pad. That way, when a Write chunk is present, the transport knows what byte range in the Reply message is supposed to be matched with the chunk. Note that the Linux NFS server implementation of NFS/RDMA can currently handle only one Write chunk per RPC-over-RDMA message. This simplifies the implementation of this fix. Fixes: b04209806384 ("nfsd4: allow exotic read compounds") Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=198053 Signed-off-by: Chuck Lever Cc: Timo Rothenpieler Signed-off-by: Greg Kroah-Hartman

SUNRPC: Allow further customisation of RPC program registration

2019-04-24T13:46:35+00:00

Add a callback to allow customisation of the rpcbind registration. When clients have the ability to turn on and off version support, we want to allow them to also prevent registration of those versions with the rpc portmapper. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields

SUNRPC: Add a callback to initialise server requests

2019-04-24T13:46:34+00:00

Add a callback to help initialise server requests before they are processed. This will allow us to clean up the NFS server version support, and to make it container safe. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields

SUNRPC/nfs: Fix return value for nfs4_callback_compound()

2019-04-24T13:46:34+00:00

RPC server procedures are normally expected to return a __be32 encoded status value of type 'enum rpc_accept_stat', however at least one function wants to return an authentication status of type 'enum rpc_auth_stat' in the case where authentication fails. This patch adds functionality to allow this. Fixes: a4e187d83d88 ("NFS: Don't drop CB requests with invalid principals") Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields

sunrpc: replace svc_serv->sv_bc_xprt by boolean flag

2018-12-28T02:01:41+00:00

svc_serv-> sv_bc_xprt is netns-unsafe and cannot be used as pointer. To prevent its misuse in future it is replaced by new boolean flag. Signed-off-by: Vasily Averin Signed-off-by: J. Bruce Fields

sunrpc: use-after-free in svc_process_common()

2018-12-28T02:00:58+00:00

if node have NFSv41+ mounts inside several net namespaces it can lead to use-after-free in svc_process_common() svc_process_common() /* Setup reply header */ rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp); <<< HERE svc_process_common() can use incorrect rqstp->rq_xprt, its caller function bc_svc_process() takes it from serv->sv_bc_xprt. The problem is that serv is global structure but sv_bc_xprt is assigned per-netnamespace. According to Trond, the whole "let's set up rqstp->rq_xprt for the back channel" is nothing but a giant hack in order to work around the fact that svc_process_common() uses it to find the xpt_ops, and perform a couple of (meaningless for the back channel) tests of xpt_flags. All we really need in svc_process_common() is to be able to run rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr() Bruce J Fields points that this xpo_prep_reply_hdr() call is an awfully roundabout way just to do "svc_putnl(resv, 0);" in the tcp case. This patch does not initialiuze rqstp->rq_xprt in bc_svc_process(), now it calls svc_process_common() with rqstp->rq_xprt = NULL. To adjust reply header svc_process_common() just check rqstp->rq_prot and calls svc_tcp_prep_reply_hdr() for tcp case. To handle rqstp->rq_xprt = NULL case in functions called from svc_process_common() patch intruduces net namespace pointer svc_rqst->rq_bc_net and adjust SVC_NET() definition. Some other function was also adopted to properly handle described case. Signed-off-by: Vasily Averin Cc: stable@vger.kernel.org Fixes: 23c20ecd4475 ("NFS: callback up - users counting cleanup") Signed-off-by: J. Bruce Fields

NFSD: Handle full-length symlinks

2018-08-09T20:11:21+00:00

I've given up on the idea of zero-copy handling of SYMLINK on the server side. This is because the Linux VFS symlink API requires the symlink pathname to be in a NUL-terminated kmalloc'd buffer. The NUL-termination is going to be problematic (watching out for landing on a page boundary and dealing with a 4096-byte pathname). I don't believe that SYMLINK creation is on a performance path or is requested frequently enough that it will cause noticeable CPU cache pollution due to data copies. There will be two places where a transport callout will be necessary to fill in the rqstp: one will be in the svc_fill_symlink_pathname() helper that is used by NFSv2 and NFSv3, and the other will be in nfsd4_decode_create(). Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields

NFSD: Refactor the generic write vector fill helper

2018-08-09T20:11:21+00:00

fill_in_write_vector() is nearly the same logic as svc_fill_write_vector(), but there are a few differences so that the former can handle multiple WRITE payloads in a single COMPOUND. svc_fill_write_vector() can be adjusted so that it can be used in the NFSv4 WRITE code path too. Instead of assuming the pages are coming from rq_args.pages, have the caller pass in the page list. The immediate benefit is a reduction of code duplication. It also prevents the NFSv4 WRITE decoder from passing an empty vector element when the transport has provided the payload in the xdr_buf's page array. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields

NFSD: Clean up legacy NFS SYMLINK argument XDR decoders

2018-04-03T19:08:16+00:00

Move common code in NFSD's legacy SYMLINK decoders into a helper. The immediate benefits include: - one fewer data copies on transports that support DDP - consistent error checking across all versions - reduction of code duplication - support for both legal forms of SYMLINK requests on RDMA transports for all versions of NFS (in particular, NFSv2, for completeness) In the long term, this helper is an appropriate spot to perform a per-transport call-out to fill the pathname argument using, say, RDMA Reads. Filling the pathname in the proc function also means that eventually the incoming filehandle can be interpreted so that filesystem- specific memory can be allocated as a sink for the pathname argument, rather than using anonymous pages. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields

NFSD: Clean up legacy NFS WRITE argument XDR decoders

2018-04-03T19:08:16+00:00

Move common code in NFSD's legacy NFS WRITE decoders into a helper. The immediate benefit is reduction of code duplication and some nice micro-optimizations (see below). In the long term, this helper can perform a per-transport call-out to fill the rq_vec (say, using RDMA Reads). The legacy WRITE decoders and procs are changed to work like NFSv4, which constructs the rq_vec just before it is about to call vfs_writev. Why? Calling a transport call-out from the proc instead of the XDR decoder means that the incoming FH can be resolved to a particular filesystem and file. This would allow pages from the backing file to be presented to the transport to be filled, rather than presenting anonymous pages and copying or flipping them into the file's page cache later. I also prefer using the pages in rq_arg.pages, instead of pulling the data pages directly out of the rqstp::rq_pages array. This is currently the way the NFSv3 write decoder works, but the other two do not seem to take this approach. Fixing this removes the only reference to rq_pages found in NFSD, eliminating an NFSD assumption about how transports use the pages in rq_pages. Lastly, avoid setting up the first element of rq_vec as a zero- length buffer. This happens with an RDMA transport when a normal Read chunk is present because the data payload is in rq_arg's page list (none of it is in the head buffer). Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields