- 18 6月, 2009 3 次提交
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由 Ricardo Labiaga 提交于
Reading and storing the RPC direction is a three step process. 1. xs_tcp_read_calldir() reads the RPC direction, but it will not store it in the XDR buffer since the 'struct rpc_rqst' is not yet available. 2. The 'struct rpc_rqst' is obtained during the TCP_RCV_COPY_DATA state. This state need not necessarily be preceeded by the TCP_RCV_READ_CALLDIR. For example, we may be reading a continuation packet to a large reply. Therefore, we can't simply obtain the 'struct rpc_rqst' during the TCP_RCV_READ_CALLDIR state and assume it's available during TCP_RCV_COPY_DATA. This patch adds a new TCP_RCV_READ_CALLDIR flag to indicate the need to read the RPC direction. It then uses TCP_RCV_COPY_CALLDIR to indicate the RPC direction needs to be saved after the 'struct rpc_rqst' has been allocated. 3. The 'struct rpc_rqst' is obtained by the xs_tcp_read_data() helper functions. xs_tcp_read_common() then saves the RPC direction in the XDR buffer if TCP_RCV_COPY_CALLDIR is set. This will happen when we're reading the data immediately after the direction was read. xs_tcp_read_common() then clears this flag. [was nfs41: Skip past the RPC call direction] Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: NBenny Halevy <bhalevy@panasas.com> [nfs41: sunrpc: Add RPC direction back into the XDR buffer] Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: NBenny Halevy <bhalevy@panasas.com> [nfs41: sunrpc: Don't skip past the RPC call direction] Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
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由 Ricardo Labiaga 提交于
NFSv4.1 callbacks can arrive over an existing connection. This patch adds the logic to read the RPC call direction (call or reply). It does this by updating the state machine to look for the call direction invoking xs_tcp_read_calldir(...) after reading the XID. [nfs41: Keep track of RPC call/reply direction with a flag] As per 11/14/08 review of RFC 53/85. Add a new flag to track whether the incoming message is an RPC call or an RPC reply. TCP_RPC_REPLY is set in the 'struct sock_xprt' tcp_flags in xs_tcp_read_calldir() if the message is an RPC reply sent on the forechannel. It is cleared if the message is an RPC request sent on the back channel. Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
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由 Andy Adamson 提交于
Signed-off-by: Andy Adamson<andros@netapp.com> Signed-off-by: NBenny Halevy <bhalevy@panasas.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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- 28 5月, 2009 2 次提交
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由 Steve Wise 提交于
The svcrdma module was incorrectly unmapping the RPCRDMA header page. On IBM pserver systems this causes a resource leak that results in running out of bus address space (10 cthon iterations will reproduce it). The code was mapping the full page but only unmapping the actual header length. The fix is to only map the header length. I also cleaned up the use of ib_dma_map_page() calls since the unmap logic always uses ib_dma_unmap_single(). I made these symmetrical. Signed-off-by: NSteve Wise <swise@opengridcomputing.com> Signed-off-by: NTom Tucker <tom@opengridcomputing.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 J. Bruce Fields 提交于
This reverts commit 47a14ef1 "svcrpc: take advantage of tcp autotuning", which uncovered some further problems in the server rpc code, causing significant performance regressions in common cases. We will likely reinstate this patch after releasing 2.6.30 and applying some work on the underlying fixes to the problem (developed by Trond). Reported-by: NJeff Moyer <jmoyer@redhat.com> Cc: Olga Kornievskaia <aglo@citi.umich.edu> Cc: Jim Rees <rees@umich.edu> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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- 27 5月, 2009 1 次提交
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由 Vu Pham 提交于
mlx4/connectX FRMR requires local write enable together with remote rdma write enable. This fixes NFS/RDMA operation over the ConnectX Infiniband HCA in the default memreg mode. Signed-off-by: NVu Pham <vu@mellanox.com> Signed-off-by: NTom Talpey <tmtalpey@gmail.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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- 04 5月, 2009 1 次提交
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由 Steve Wise 提交于
These fixes resolved crashes due to resource leak BUG_ON checks. The resource leaks were detected by introducing asynchronous transport errors. Signed-off-by: NSteve Wise <swise@opengridcomputing.com> Signed-off-by: NTom Tucker <tom@opengridcomputing.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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- 03 5月, 2009 1 次提交
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由 Trond Myklebust 提交于
See http://bugzilla.kernel.org/show_bug.cgi?id=13034 If the port gets into a TIME_WAIT state, then we cannot reconnect without binding to a new port. Tested-by: NPetr Vandrovec <petr@vandrovec.name> Tested-by: NJean Delvare <khali@linux-fr.org> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 4月, 2009 1 次提交
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由 Steve Wise 提交于
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: NSteve Wise <swise@opengridcomputing.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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- 04 4月, 2009 1 次提交
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由 Andy Adamson 提交于
On an NFSv4.1 server cache miss that causes an upcall, NFS4ERR_DELAY will be returned. It is up to the NFSv4.1 client to resend only the operations that have not been processed. Initialize rq_usedeferral to 1 in svc_process(). It sill be turned off in nfsd4_proc_compound() only when NFSv4.1 Sessions are used. Note: this isn't an adequate solution on its own. It's acceptable as a way to get some minimal 4.1 up and working, but we're going to have to find a way to avoid returning DELAY in all common cases before 4.1 can really be considered ready. Signed-off-by: NAndy Adamson <andros@netapp.com> Signed-off-by: NBenny Halevy <bhalevy@panasas.com> [nfsd41: reverse rq_nodeferral negative logic] Signed-off-by: NBenny Halevy <bhalevy@panasas.com> [sunrpc: initialize rq_usedeferral] Signed-off-by: NAndy Adamson <andros@netapp.com> Signed-off-by: NBenny Halevy <bhalevy@panasas.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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- 02 4月, 2009 1 次提交
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由 Trond Myklebust 提交于
Also ensure that we use the protocol family instead of the address family when calling sock_create_kern(). Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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- 31 3月, 2009 1 次提交
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由 Alexey Dobriyan 提交于
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy as correctly noted at bug #12454. Someone can lookup entry with NULL ->owner, thus not pinning enything, and release it later resulting in module refcount underflow. We can keep ->owner and supply it at registration time like ->proc_fops and ->data. But this leaves ->owner as easy-manipulative field (just one C assignment) and somebody will forget to unpin previous/pin current module when switching ->owner. ->proc_fops is declared as "const" which should give some thoughts. ->read_proc/->write_proc were just fixed to not require ->owner for protection. rmmod'ed directories will be empty and return "." and ".." -- no harm. And directories with tricky enough readdir and lookup shouldn't be modular. We definitely don't want such modular code. Removing ->owner will also make PDE smaller. So, let's nuke it. Kudos to Jeff Layton for reminding about this, let's say, oversight. http://bugzilla.kernel.org/show_bug.cgi?id=12454Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
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- 30 3月, 2009 2 次提交
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由 Matt LaPlante 提交于
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com> Acked-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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由 Rusty Russell 提交于
Impact: cleanup Time to clean up remaining laggards using the old cpu_ functions. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Trond.Myklebust@netapp.com
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- 29 3月, 2009 16 次提交
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由 Chuck Lever 提交于
We just augmented the kernel's RPC service registration code so that it automatically adjusts to what is supported in user space. Thus we no longer need the kernel configuration option to enable registering RPC services with v4 -- it's all done automatically. This patch is part of a series that addresses http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
Move error reporting for RPC registration to rpcb_register's caller. This way the caller can choose to recover silently from certain errors, but report errors it does not recognize. Error reporting for kernel RPC service registration is now handled in one place. This patch is part of a series that addresses http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
The kernel registers RPC services with the local portmapper with an rpcbind SET upcall to the local portmapper. Traditionally, this used rpcbind v2 (PMAP), but registering RPC services that support IPv6 requires rpcbind v3 or v4. Since we now want separate PF_INET and PF_INET6 listeners for each kernel RPC service, svc_register() will do only one of those registrations at a time. For PF_INET, it tries an rpcb v4 SET upcall first; if that fails, it does a legacy portmap SET. This makes it entirely backwards compatible with legacy user space, but allows a proper v4 SET to be used if rpcbind is available. For PF_INET6, it does an rpcb v4 SET upcall. If that fails, it fails the registration, and thus the transport creation. This let's the kernel detect if user space is able to support IPv6 RPC services, and thus whether it should maintain a PF_INET6 listener for each service at all. This provides complete backwards compatibilty with legacy user space that only supports rpcbind v2. The only down-side is that registering a new kernel RPC service may take an extra exchange with the local portmapper on legacy systems, but this is an infrequent operation and is done over UDP (no lingering sockets in TIMEWAIT), so it shouldn't be consequential. This patch is part of a series that addresses http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
Our initial implementation of svc_unregister() assumed that PMAP_UNSET cleared all rpcbind registrations for a [program, version] tuple. However, we now have evidence that PMAP_UNSET clears only "inet" entries, and not "inet6" entries, in the rpcbind database. For backwards compatibility with the legacy portmapper, the svc_unregister() function also must work if user space doesn't support rpcbind version 4 at all. Thus we'll send an rpcbind v4 UNSET, and if that fails, we'll send a PMAP_UNSET. This simplifies the code in svc_unregister() and provides better backwards compatibility with legacy user space that does not support rpcbind version 4. We can get rid of the conditional compilation in here as well. This patch is part of a series that addresses http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
The user space TI-RPC library uses an empty string for the universal address when unregistering all target addresses for [program, version]. The kernel's rpcb client should behave the same way. Here, we are switching between several registration methods based on the protocol family of the incoming address. Rename the other rpcbind v4 registration functions to make it clear that they, as well, are switched on protocol family. In /etc/netconfig, this is either "inet" or "inet6". NB: The loopback protocol families are not supported in the kernel. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
RFC 1833 has little to say about the contents of r_owner; it only specifies that it is a string, and states that it is used to control who can UNSET an entry. Our port of rpcbind (from Sun) assumes this string contains a numeric UID value, not alphabetical or symbolic characters, but checks this value only for AF_LOCAL RPCB_SET or RPCB_UNSET requests. In all other cases, rpcbind ignores the contents of the r_owner string. The reference user space implementation of rpcb_set(3) uses a numeric UID for all SET/UNSET requests (even via the network) and an empty string for all other requests. We emulate that behavior here to maintain bug-for-bug compatibility. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
Clean up: Simplify rpcb_v4_register() and its helpers by moving the details of sockaddr type casting to rpcb_v4_register()'s helper functions. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
The RPC client returns -EPROTONOSUPPORT if there is a protocol version mismatch (ie the remote RPC server doesn't support the RPC protocol version sent by the client). Helpers for the svc_register() function return -EPROTONOSUPPORT if they don't recognize the passed-in IPPROTO_ value. These are two entirely different failure modes. Have the helpers return -ENOPROTOOPT instead of -EPROTONOSUPPORT. This will allow callers to determine more precisely what the underlying problem is, and decide to report or recover appropriately. This patch is part of a series that addresses http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
The kernel uses an IPv6 loopback address when registering its AF_INET6 RPC services so that it can tell whether the local portmapper is actually IPv6-enabled. Since the legacy portmapper doesn't listen on IPv6, however, this causes a long timeout on older systems if the kernel happens to try creating and registering an AF_INET6 RPC service. Originally I wanted to use a connected transport (either TCP or connected UDP) so that the upcall would fail immediately if the portmapper wasn't listening on IPv6, but we never agreed on what transport to use. In the end, it's of little consequence to the kernel whether the local portmapper is listening on IPv6. It's only important whether the portmapper supports rpcbind v4. And the kernel can't tell that at all if it is sending requests via IPv6 -- the portmapper will just ignore them. So, send both rpcbind v2 and v4 SET/UNSET requests via IPv4 loopback to maintain better backwards compatibility between new kernels and legacy user space, and prevent multi-second hangs in some cases when the kernel attempts to register RPC services. This patch is part of a series that addresses http://bugzilla.kernel.org/show_bug.cgi?id=12256Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
We are about to convert to using separate RPC listener sockets for PF_INET and PF_INET6. This echoes the way IPv6 is handled in user space by TI-RPC, and eliminates the need for ULPs to worry about mapped IPv4 AF_INET6 addresses when doing address comparisons. Start by setting the IPV6ONLY flag on PF_INET6 RPC listener sockets. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
Since an RPC service listener's protocol family is specified now via svc_create_xprt(), it no longer needs to be passed to svc_create() or svc_create_pooled(). Remove that argument from the synopsis of those functions, and remove the sv_family field from the svc_serv struct. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
The sv_family field is going away. Pass a protocol family argument to svc_create_xprt() instead of extracting the family from the passed-in svc_serv struct. Again, as this is a listener socket and not an address, we make this new argument an "int" protocol family, instead of an "sa_family_t." Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
Since the sv_family field is going away, modify svc_setup_socket() to extract the protocol family from the passed-in socket instead of from the passed-in svc_serv struct. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
The sv_family field is going away. Instead of using sv_family, have the svc_register() function take a protocol family argument. Since this argument represents a protocol family, and not an address family, this argument takes an int, as this is what is passed to sock_create_kern(). Also make sure svc_register's helpers are checking for PF_FOO instead of AF_FOO. The value of [AP]F_FOO are equivalent; this is simply a symbolic change to reflect the semantics of the value stored in that variable. sock_create_kern() should return EPFNOSUPPORT if the passed-in protocol family isn't supported, but it uses EAFNOSUPPORT for this case. We will stick with that tradition here, as svc_register() is called by the RPC server in the same path as sock_create_kern(). Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
Clean up: add documentating comment and use appropriate data types for svc_find_xprt()'s arguments. This also eliminates a mixed sign comparison: @port was an int, while the return value of svc_xprt_local_port() is an unsigned short. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Chuck Lever 提交于
In 2007, commit e65fe397 added additional sanity checking to rpcb_decode_getaddr() to make sure we were getting a reply that was long enough to be an actual universal address. If the uaddr string isn't long enough, the XDR decoder returns EIO. However, an empty string is a valid RPCB_GETADDR response if the requested service isn't registered. Moreover, "::.n.m" is also a valid RPCB_GETADDR response for IPv6 addresses that is shorter than rpcb_decode_getaddr()'s lower limit of 11. So this sanity check introduced a regression for rpcbind requests against IPv6 remotes. So revert the lower bound check added by commit e65fe397, and add an explicit check for an empty uaddr string, similar to libtirpc's rpcb_getaddr(3). Pointed-out-by: NJeff Layton <jlayton@redhat.com> Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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- 28 3月, 2009 2 次提交
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由 ideawu 提交于
There is no need to set rqstp->rq_server to serv, while serv is initialized as rqstp->rq_server at previous line. And between these two lines, there is no change to rqstp->rq_server. Signed-off-by: Nideawu <ideawu@163.com> Reviewed-by: NTom Tucker <tom@opengridcomputing.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 20 3月, 2009 5 次提交
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由 Tom Talpey 提交于
printk formats in prior commit were reversed/incorrect. Compiled without warning on x86 and x86_64, but detected on ppc. Signed-off-by: NTom Talpey <tmtalpey@gmail.com> Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Trond Myklebust 提交于
As long as one task is holding the socket lock, then calls to xprt_force_disconnect(xprt) will not succeed in shutting down the socket. In particular, this would mean that a server initiated shutdown will not succeed until the lock is relinquished. In order to avoid the deadlock, we should ensure that xs_tcp_send_request() closes the socket on EPIPE errors too. Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Trond Myklebust 提交于
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Trond Myklebust 提交于
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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由 Trond Myklebust 提交于
This fixes a regression against FreeBSD servers as reported by Tomas Kasparek. Apparently when using RPC over a TCP socket, the FreeBSD servers don't ever react to the client closing the socket, and so commit e06799f9 (SUNRPC: Use shutdown() instead of close() when disconnecting a TCP socket) causes the setup to hang forever whenever the client attempts to close and then reconnect. We break the deadlock by adding a 'linger2' style timeout to the socket, after which, the client will abort the connection using a TCP 'RST'. The default timeout is set to 15 seconds. A subsequent patch will put it under user control by means of a systctl. Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
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- 19 3月, 2009 3 次提交
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由 Olga Kornievskaia 提交于
Allow the NFSv4 server to make use of TCP autotuning behaviour, which was previously disabled by setting the sk_userlocks variable. Set the receive buffers to be big enough to receive the whole RPC request, and set this for the listening socket, not the accept socket. Remove the code that readjusts the receive/send buffer sizes for the accepted socket. Previously this code was used to influence the TCP window management behaviour, which is no longer needed when autotuning is enabled. This can improve IO bandwidth on networks with high bandwidth-delay products, where a large tcp window is required. It also simplifies performance tuning, since getting adequate tcp buffers previously required increasing the number of nfsd threads. Signed-off-by: NOlga Kornievskaia <aglo@citi.umich.edu> Cc: Jim Rees <rees@umich.edu> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 Greg Banks 提交于
Add /proc/fs/nfsd/pool_stats to export to userspace various statistics about the operation of rpc server thread pools. This patch is based on a forward-ported version of knfsd-add-pool-thread-stats which has been shipping in the SGI "Enhanced NFS" product since 2006 and which was previously posted: http://article.gmane.org/gmane.linux.nfs/10375 It has also been updated thus: * moved EXPORT_SYMBOL() to near the function it exports * made the new struct struct seq_operations const * used SEQ_START_TOKEN instead of ((void *)1) * merged fix from SGI PV 990526 "sunrpc: use dprintk instead of printk in svc_pool_stats_*()" by Harshula Jayasuriya. * merged fix from SGI PV 964001 "Crash reading pool_stats before nfsds are started". Signed-off-by: NGreg Banks <gnb@sgi.com> Signed-off-by: NHarshula Jayasuriya <harshula@sgi.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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由 Greg Banks 提交于
Avoid overloading the CPU scheduler with enormous load averages when handling high call-rate NFS loads. When the knfsd bottom half is made aware of an incoming call by the socket layer, it tries to choose an nfsd thread and wake it up. As long as there are idle threads, one will be woken up. If there are lot of nfsd threads (a sensible configuration when the server is disk-bound or is running an HSM), there will be many more nfsd threads than CPUs to run them. Under a high call-rate low service-time workload, the result is that almost every nfsd is runnable, but only a handful are actually able to run. This situation causes two significant problems: 1. The CPU scheduler takes over 10% of each CPU, which is robbing the nfsd threads of valuable CPU time. 2. At a high enough load, the nfsd threads starve userspace threads of CPU time, to the point where daemons like portmap and rpc.mountd do not schedule for tens of seconds at a time. Clients attempting to mount an NFS filesystem timeout at the very first step (opening a TCP connection to portmap) because portmap cannot wake up from select() and call accept() in time. Disclaimer: these effects were observed on a SLES9 kernel, modern kernels' schedulers may behave more gracefully. The solution is simple: keep in each svc_pool a counter of the number of threads which have been woken but have not yet run, and do not wake any more if that count reaches an arbitrary small threshold. Testing was on a 4 CPU 4 NIC Altix using 4 IRIX clients, each with 16 synthetic client threads simulating an rsync (i.e. recursive directory listing) workload reading from an i386 RH9 install image (161480 regular files in 10841 directories) on the server. That tree is small enough to fill in the server's RAM so no disk traffic was involved. This setup gives a sustained call rate in excess of 60000 calls/sec before being CPU-bound on the server. The server was running 128 nfsds. Profiling showed schedule() taking 6.7% of every CPU, and __wake_up() taking 5.2%. This patch drops those contributions to 3.0% and 2.2%. Load average was over 120 before the patch, and 20.9 after. This patch is a forward-ported version of knfsd-avoid-nfsd-overload which has been shipping in the SGI "Enhanced NFS" product since 2006. It has been posted before: http://article.gmane.org/gmane.linux.nfs/10374Signed-off-by: NGreg Banks <gnb@sgi.com> Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
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