For NFS sessions, change the autoreconnect options to be :
-1: (default) retry connectiong back to the server forever. Just like
normal NFS clients do.
0: Do not attempt reconnecting at all. Immediately fail and return an
error back to the application on session loss.
>=1: Retry connecting to the server this many times before giving up.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Limit the number of retries when autoreconnecting (to an arbitrary 10)
and return an error to the application if this limit is reached.
Without this, libnfs retries indefinitely and consumes 100% CPU.
See also: https://bugzilla.gnome.org/show_bug.cgi?id=762544
Signed-off-by: Ross Lagerwall <rosslagerwall@gmail.com>
rpc_read_from_socket can currently only read one PDU in each rpc_service invocation even
if there is more data available on the socket. This patch reads all PDUs until the socket
would block.
Signed-off-by: Peter Lieven <pl@kamp.de>
we always read 4 bytes to get the PDU size and than realloc
these 4 bytes to the full size of the PDU. Avoid this by
using a static buf for the record marker.
Signed-off-by: Peter Lieven <pl@kamp.de>
There is no need to allocate and deallocate this structue every time
we update the udp destinateion.
For the client side, where we set the destination just once per lifetime
of the context it might not matter too much but once we add udp server support
we will need to update the sockaddr for every rpc we receive.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Add a flags field to rpc_pdu and add a flag that indicates that the PDU
should be discarded as soon as it has been written to the socket.
We do not put it on the waitpdu queue nor do we wait for a reply.
This will later be used for when we are sending replies back to a client
when operating in a server context.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
`nfs_set_interface` and `rpc_set_interface` APIs, or via the
NFS URL `if=<interface>` parameter. This feature requires
`root` permissions.
NOTE: This has only been compiled and tested on Ubuntu 14.04. It's
unlikely that it'll work on other platforms without modification,
particularly around the inclusion of <net/if.h> and IFNAMSIZ define
in `libnfs-private.h`.
the only call thar really needs a big encodebuf is WRITE. So give each
PDU its private encodebuf. This avoids the need to memcpy the data from
the static rpc->encodebuf to the pdu->outdata.data.
Signed-off-by: Peter Lieven <pl@kamp.de>
this adds support for a simple read cache to avoid unnecassary request
to the NFS storage. libnfs by design cannot benefit from the kernel page
cache and suffers from performance penalties in some cases when compared
with a file accessed via kernel NFS.
This patch exposes 3 new API calls:
void nfs_set_pagecache(struct nfs_context *nfs, uint32_t v);
void nfs_set_pagecache_ttl(struct nfs_context *nfs, uint32_t v);
void nfs_pagecache_invalidate(struct nfs_context *nfs, struct nfsfh *nfsfh);
As well as the two new URL parameters pagecache and pagecache_ttl.
pagecache is defined in number of pages where a page is always NFS_BLKSIZE (4kB).
pagecache_ttl takes the page timeout in seconds where 0 means infinite.
Signed-off-by: Peter Lieven <pl@kamp.de>
Add support to timeout sync functions.
Add a field to the rpc context to specify the timeout for functions.
Currently only sync functions support a timeout.
We can not have a static rpc->inbuf buffer since that will no longer guarantee
that the received buffer is valid for the duration of callbacks.
One of the problems is that if we issue new (sync) RPCs from within a
callback, that will overwrite and invalidate the receive buffer that
we passed to the callback.
Revert "init: do not leak rpc->inbuf"
This reverts commit f7bc4c8bb1.
Revert "socket: we have to use memmove in rpc_read_from_socket"
This reverts commit 24429e95b8.
Revert "socket: make rpc->inbuf static and simplify receive logic"
This reverts commit 7000a0aa04.
There is no guarantee that we get the same fd again when
reestablishing a session. But if the fd changes during a
reconnect we might up with a client application busy polling
on the old fd.
Qemu registers a read handler on the current fd, but is
not realizing fd changes. So we busy poll on the old fd for good.
Things are working (except for the busy polling) until
a drain all is issued. At this point Qemu deadlocks.
Signed-off-by: Peter Lieven <pl@kamp.de>
only logging to stderr is supported at the moment. Per default
there is no output. Its possible to set the log level via
debug url parameter.
Example:
nfs-ls nfs://127.0.0.1/export?debug=2
Signed-off-by: Peter Lieven <pl@kamp.de>
the write limit of libnfs has been 1M since a long time.
Restrict rtmax and wrmax to 1M and error out otherwise.
Limit the PDU size when reading from socket to rule out
malicious servers forcing us to allocate a lot of memory.
Signed-off-by: Peter Lieven <pl@kamp.de>
Update the configure to add some sanity -W arguments.
A good start is probably :
-Wall -Werror -Wshadow -Wno-write-strings -Wstrict-prototypes
-Wpointer-arith -Wcast-align -Wno-strict-aliasing
Fixup the paces in the code that triggers.
(one of which is readahead code which is perhaps broken?)
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
This patch add support for an internal readahead machanism. The maximum readahead
size can be specified via URL parameter readahead. This should significantly
speed up small sequential reads.
Signed-off-by: Peter Lieven <pl@kamp.de>
NFS servers can respond to requests in any order, and they do. In our
tests there is also some clustering to the responses; it could be
because eg. requests are served synchronously if the data is in the cache.
Introduce a hash table so that we are able to find the pdu quickly in
all cases, assuming random distribution of the responses.
When making many concurrent requests (as is likely in any performance
criticial application), the use of SLIST_REMOVE and SLIST_ADD_END are
a severe bottleneck because of their linear search.
I considered using a double-linked list but it was unnecessary to
allocate the additional memory for each list entry.
Instead, continue to use a single-linked list but retain:
* a pointer to the end of the list; and
* a pointer to the previous entry during a linear search.
The former would makes append operations O(1) time, and the latter
does the same for removal. We can do this because removal only happens
within the linear search, and there is no random access to the queue.
This allows to connect with an alternate uid or gid than that
of the current user.
Example:
examples/nfs-ls nfs://10.0.0.1/export?uid=1000&gid=33
Signed-off-by: Peter Lieven <pl@kamp.de>
This allows indirect support for a configurable connect timeout.
Linux uses a exponential backoff for SYN retries starting
with 1 second.
This means for a value n for TCP_SYNCNT, the connect will
effectively timeout after 2^(n+1)-1 seconds.
Example:
examples/nfs-ls nfs://10.0.0.1/export?tcp-syncnt=1
Signed-off-by: Peter Lieven <pl@kamp.de>
This patch switches libnfs over to use precompiled rpcgen files
and using ZDR. ZDR is a trivial reimplementation of XDR that is built in
into libnfs.
This removes the dependencies of rpc/xdr completely and allow us to build on any
system, even systems where rpcgen and librpc/libxdr are not generally available.
Ronnie Sahlberg