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2022-01-17Merge branch 'signal-for-v5.17' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull signal/exit/ptrace updates from Eric Biederman: "This set of changes deletes some dead code, makes a lot of cleanups which hopefully make the code easier to follow, and fixes bugs found along the way. The end-game which I have not yet reached yet is for fatal signals that generate coredumps to be short-circuit deliverable from complete_signal, for force_siginfo_to_task not to require changing userspace configured signal delivery state, and for the ptrace stops to always happen in locations where we can guarantee on all architectures that the all of the registers are saved and available on the stack. Removal of profile_task_ext, profile_munmap, and profile_handoff_task are the big successes for dead code removal this round. A bunch of small bug fixes are included, as most of the issues reported were small enough that they would not affect bisection so I simply added the fixes and did not fold the fixes into the changes they were fixing. There was a bug that broke coredumps piped to systemd-coredump. I dropped the change that caused that bug and replaced it entirely with something much more restrained. Unfortunately that required some rebasing. Some successes after this set of changes: There are few enough calls to do_exit to audit in a reasonable amount of time. The lifetime of struct kthread now matches the lifetime of struct task, and the pointer to struct kthread is no longer stored in set_child_tid. The flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is removed. Issues where task->exit_code was examined with signal->group_exit_code should been examined were fixed. There are several loosely related changes included because I am cleaning up and if I don't include them they will probably get lost. The original postings of these changes can be found at: https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org I trimmed back the last set of changes to only the obviously correct once. Simply because there was less time for review than I had hoped" * 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits) ptrace/m68k: Stop open coding ptrace_report_syscall ptrace: Remove unused regs argument from ptrace_report_syscall ptrace: Remove second setting of PT_SEIZED in ptrace_attach taskstats: Cleanup the use of task->exit_code exit: Use the correct exit_code in /proc/<pid>/stat exit: Fix the exit_code for wait_task_zombie exit: Coredumps reach do_group_exit exit: Remove profile_handoff_task exit: Remove profile_task_exit & profile_munmap signal: clean up kernel-doc comments signal: Remove the helper signal_group_exit signal: Rename group_exit_task group_exec_task coredump: Stop setting signal->group_exit_task signal: Remove SIGNAL_GROUP_COREDUMP signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process signal: Make coredump handling explicit in complete_signal signal: Have prepare_signal detect coredumps using signal->core_state signal: Have the oom killer detect coredumps using signal->core_state exit: Move force_uaccess back into do_exit exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit ...
2021-12-13lockd: use svc_set_num_threads() for thread start and stopNeilBrown1-3/+3
svc_set_num_threads() does everything that lockd_start_svc() does, except set sv_maxconn. It also (when passed 0) finds the threads and stops them with kthread_stop(). So move the setting for sv_maxconn, and use svc_set_num_thread() We now don't need nlmsvc_task. Now that we use svc_set_num_threads() it makes sense to set svo_module. This request that the thread exists with module_put_and_exit(). Also fix the documentation for svo_module to make this explicit. svc_prepare_thread is now only used where it is defined, so it can be made static. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: move the pool_map definitions (back) into svc.cNeilBrown1-25/+0
These definitions are not used outside of svc.c, and there is no evidence that they ever have been. So move them into svc.c and make the declarations 'static'. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: discard svo_setup and rename svc_set_num_threads_sync()NeilBrown1-4/+0
The ->svo_setup callback serves no purpose. It is always called from within the same module that chooses which callback is needed. So discard it and call the relevant function directly. Now that svc_set_num_threads() is no longer used remove it and rename svc_set_num_threads_sync() to remove the "_sync" suffix. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Make it possible to use svc_set_num_threads_syncNeilBrown1-0/+13
nfsd cannot currently use svc_set_num_threads_sync. It instead uses svc_set_num_threads which does *not* wait for threads to all exit, and has a separate mechanism (nfsd_shutdown_complete) to wait for completion. The reason that nfsd is unlike other services is that nfsd threads can exit separately from svc_set_num_threads being called - they die on receipt of SIGKILL. Also, when the last thread exits, the service must be shut down (sockets closed). For this, the nfsd_mutex needs to be taken, and as that mutex needs to be held while svc_set_num_threads is called, the one cannot wait for the other. This patch changes the nfsd thread so that it can drop the ref on the service without blocking on nfsd_mutex, so that svc_set_num_threads_sync can be used: - if it can drop a non-last reference, it does that. This does not trigger shutdown and does not require a mutex. This will likely happen for all but the last thread signalled, and for all threads being shut down by nfsd_shutdown_threads() - if it can get the mutex without blocking (trylock), it does that and then drops the reference. This will likely happen for the last thread killed by SIGKILL - Otherwise there might be an unrelated task holding the mutex, possibly in another network namespace, or nfsd_shutdown_threads() might be just about to get a reference on the service, after which we can drop ours safely. We cannot conveniently get wakeup notifications on these events, and we are unlikely to need to, so we sleep briefly and check again. With this we can discard nfsd_shutdown_complete and nfsd_complete_shutdown(), and switch to svc_set_num_threads_sync. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: stop using ->sv_nrthreads as a refcountNeilBrown1-10/+4
The use of sv_nrthreads as a general refcount results in clumsy code, as is seen by various comments needed to explain the situation. This patch introduces a 'struct kref' and uses that for reference counting, leaving sv_nrthreads to be a pure count of threads. The kref is managed particularly in svc_get() and svc_put(), and also nfsd_put(); svc_destroy() now takes a pointer to the embedded kref, rather than to the serv. nfsd allows the svc_serv to exist with ->sv_nrhtreads being zero. This happens when a transport is created before the first thread is started. To support this, a 'keep_active' flag is introduced which holds a ref on the svc_serv. This is set when any listening socket is successfully added (unless there are running threads), and cleared when the number of threads is set. So when the last thread exits, the nfs_serv will be destroyed. The use of 'keep_active' replaces previous code which checked if there were any permanent sockets. We no longer clear ->rq_server when nfsd() exits. This was done to prevent svc_exit_thread() from calling svc_destroy(). Instead we take an extra reference to the svc_serv to prevent svc_destroy() from being called. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC/NFSD: clean up get/put functions.NeilBrown1-3/+23
svc_destroy() is poorly named - it doesn't necessarily destroy the svc, it might just reduce the ref count. nfsd_destroy() is poorly named for the same reason. This patch: - removes the refcount functionality from svc_destroy(), moving it to a new svc_put(). Almost all previous callers of svc_destroy() now call svc_put(). - renames nfsd_destroy() to nfsd_put() and improves the code, using the new svc_destroy() rather than svc_put() - removes a few comments that explain the important for balanced get/put calls. This should be obvious. The only non-trivial part of this is that svc_destroy() would call svc_sock_update() on a non-final decrement. It can no longer do that, and svc_put() isn't really a good place of it. This call is now made from svc_exit_thread() which seems like a good place. This makes the call *before* sv_nrthreads is decremented rather than after. This is not particularly important as the call just sets a flag which causes sv_nrthreads set be checked later. A subsequent patch will improve the ordering. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: change svc_get() to return the svc.NeilBrown1-1/+2
It is common for 'get' functions to return the object that was 'got', and there are a couple of places where users of svc_get() would be a little simpler if svc_get() did that. Make it so. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-10-13SUNRPC: Change return value type of .pc_encodeChuck Lever1-1/+1
Returning an undecorated integer is an age-old trope, but it's not clear (even to previous experts in this code) that the only valid return values are 1 and 0. These functions do not return a negative errno, rpc_stat value, or a positive length. Document there are only two valid return values by having .pc_encode return only true or false. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13SUNRPC: Replace the "__be32 *p" parameter to .pc_encodeChuck Lever1-1/+2
The passed-in value of the "__be32 *p" parameter is now unused in every server-side XDR encoder, and can be removed. Note also that there is a line in each encoder that sets up a local pointer to a struct xdr_stream. Passing that pointer from the dispatcher instead saves one line per encoder function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13SUNRPC: Change return value type of .pc_decodeChuck Lever1-1/+1
Returning an undecorated integer is an age-old trope, but it's not clear (even to previous experts in this code) that the only valid return values are 1 and 0. These functions do not return a negative errno, rpc_stat value, or a positive length. Document there are only two valid return values by having .pc_decode return only true or false. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13SUNRPC: Replace the "__be32 *p" parameter to .pc_decodeChuck Lever1-1/+2
The passed-in value of the "__be32 *p" parameter is now unused in every server-side XDR decoder, and can be removed. Note also that there is a line in each decoder that sets up a local pointer to a struct xdr_stream. Passing that pointer from the dispatcher instead saves one line per decoder function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-12SUNRPC: Simplify the SVC dispatch code pathChuck Lever1-4/+1
Micro-optimization: The last user of the generic SVC dispatch code path has been removed, so svc_process_common() can be simplified. This declutters the hot path so that the by-far most common case (a dispatch function exists) is made the /only/ path. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-02NFSD: Have legacy NFSD WRITE decoders use xdr_stream_subsegment()Chuck Lever1-2/+1
Refactor. Now that the NFSv2 and NFSv3 XDR decoders have been converted to use xdr_streams, the WRITE decoder functions can use xdr_stream_subsegment() to extract the WRITE payload into its own xdr_buf, just as the NFSv4 WRITE XDR decoder currently does. That makes it possible to pass the first kvec, pages array + length, page_base, and total payload length via a single function parameter. The payload's page_base is not yet assigned or used, but will be in subsequent patches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-09-04Merge tag 'nfs-for-5.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds1-2/+1
Pull NFS client updates from Anna Schumaker: "New Features: - Better client responsiveness when server isn't replying - Use refcount_t in sunrpc rpc_client refcount tracking - Add srcaddr and dst_port to the sunrpc sysfs info files - Add basic support for connection sharing between servers with multiple NICs` Bugfixes and Cleanups: - Sunrpc tracepoint cleanups - Disconnect after ib_post_send() errors to avoid deadlocks - Fix for tearing down rpcrdma_reps - Fix a potential pNFS layoutget livelock loop - pNFS layout barrier fixes - Fix a potential memory corruption in rpc_wake_up_queued_task_set_status() - Fix reconnection locking - Fix return value of get_srcport() - Remove rpcrdma_post_sends() - Remove pNFS dead code - Remove copy size restriction for inter-server copies - Overhaul the NFS callback service - Clean up sunrpc TCP socket shutdowns - Always provide aligned buffers to RPC read layers" * tag 'nfs-for-5.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (39 commits) NFS: Always provide aligned buffers to the RPC read layers NFSv4.1 add network transport when session trunking is detected SUNRPC enforce creation of no more than max_connect xprts NFSv4 introduce max_connect mount options SUNRPC add xps_nunique_destaddr_xprts to xprt_switch_info in sysfs SUNRPC keep track of number of transports to unique addresses NFSv3: Delete duplicate judgement in nfs3_async_handle_jukebox SUNRPC: Tweak TCP socket shutdown in the RPC client SUNRPC: Simplify socket shutdown when not reusing TCP ports NFSv4.2: remove restriction of copy size for inter-server copy. NFS: Clean up the synopsis of callback process_op() NFS: Extract the xdr_init_encode/decode() calls from decode_compound NFS: Remove unused callback void decoder NFS: Add a private local dispatcher for NFSv4 callback operations SUNRPC: Eliminate the RQ_AUTHERR flag SUNRPC: Set rq_auth_stat in the pg_authenticate() callout SUNRPC: Add svc_rqst::rq_auth_stat SUNRPC: Add dst_port to the sysfs xprt info file SUNRPC: Add srcaddr as a file in sysfs sunrpc: Fix return value of get_srcport() ...
2021-08-17SUNRPC: Fix a NULL pointer deref in trace_svc_stats_latency()Chuck Lever1-0/+1
Some paths through svc_process() leave rqst->rq_procinfo set to NULL, which triggers a crash if tracing happens to be enabled. Fixes: 89ff87494c6e ("SUNRPC: Display RPC procedure names instead of proc numbers") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-17SUNRPC: Add svc_rqst_replace_page() APIChuck Lever1-0/+4
Replacing a page in rq_pages[] requires a get_page(), which is a bus-locked operation, and a put_page(), which can be even more costly. To reduce the cost of replacing a page in rq_pages[], batch the put_page() operations by collecting "freed" pages in a pagevec, and then release those pages when the pagevec is full. This pagevec is also emptied when each RPC completes. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-10SUNRPC: Eliminate the RQ_AUTHERR flagChuck Lever1-2/+0
Now that there is an alternate method for returning an auth_stat value, replace the RQ_AUTHERR flag with use of that new method. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2021-08-10SUNRPC: Add svc_rqst::rq_auth_statChuck Lever1-0/+1
I'd like to take commit 4532608d71c8 ("SUNRPC: Clean up generic dispatcher code") even further by using only private local SVC dispatchers for all kernel RPC services. This change would enable the removal of the logic that switches between svc_generic_dispatch() and a service's private dispatcher, and simplify the invocation of the service's pc_release method so that humans can visually verify that it is always invoked properly. All that will come later. First, let's provide a better way to return authentication errors from SVC dispatcher functions. Instead of overloading the dispatch method's *statp argument, add a field to struct svc_rqst that can hold an error value. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2021-03-22NFSD: Extract the svcxdr_init_encode() helperChuck Lever1-0/+25
NFSD initializes an encode xdr_stream only after the RPC layer has already inserted the RPC Reply header. Thus it behaves differently than xdr_init_encode does, which assumes the passed-in xdr_buf is entirely devoid of content. nfs4proc.c has this server-side stream initialization helper, but it is visible only to the NFSv4 code. Move this helper to a place that can be accessed by NFSv2 and NFSv3 server XDR functions. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-01-25SUNRPC: Make trace_svc_process() display the RPC procedure symbolicallyChuck Lever1-0/+1
The next few patches will employ these strings to help make server- side trace logs more human-readable. A similar technique is already in use in kernel RPC client code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-11-30SUNRPC: Prepare for xdr_stream-style decoding on the server-sideChuck Lever1-0/+16
A "permanent" struct xdr_stream is allocated in struct svc_rqst so that it is usable by all server-side decoders. A per-rqst scratch buffer is also allocated to handle decoding XDR data items that cross page boundaries. To demonstrate how it will be used, add the first call site for the new svcxdr_init_decode() API. As an additional part of the overall conversion, add symbolic constants for successful and failed XDR operations. Returning "0" is overloaded. Sometimes it means something failed, but sometimes it means success. To make it more clear when XDR decoding functions succeed or fail, introduce symbolic constants. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-11-30SUNRPC: Rename svc_encode_read_payload()Chuck Lever1-3/+3
Clean up: "result payload" is a less confusing name for these payloads. "READ payload" reflects only the NFS usage. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-05-21Merge branch 'nfsd-5.8' of git://linux-nfs.org/~cel/cel-2.6 into ↵J. Bruce Fields1-0/+1
for-5.8-incoming Highlights of this series: * Remove serialization of sending RPC/RDMA Replies * Convert the TCP socket send path to use xdr_buf::bvecs (pre-requisite for RPC-on-TLS) * Fix svcrdma backchannel sendto return code * Convert a number of dprintk call sites to use tracepoints * Fix the "suggest braces around empty body in an 'else' statement" warning
2020-05-21SUNRPC: Refactor svc_recvfrom()Chuck Lever1-0/+1
This function is not currently "generic" so remove the documenting comment and rename it appropriately. Its internals are converted to use bio_vecs for reading from the transport socket. In existing typical sunrpc uses of bio_vecs, the bio_vec array is allocated dynamically. Here, instead, an array of bio_vecs is added to svc_rqst. The lifetime of this array can be greater than one call to xpo_recvfrom(): - Multiple calls to xpo_recvfrom() might be needed to read an RPC message completely. - At some later point, rq_arg.bvecs will point to this array and it will carry the received message into svc_process(). I also expect that a future optimization will remove either the rq_vec or rq_pages array in favor of rq_bvec, thus conserving the size of struct svc_rqst. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-05-09nfsd: clients don't need to break their own delegationsJ. Bruce Fields1-0/+1
We currently revoke read delegations on any write open or any operation that modifies file data or metadata (including rename, link, and unlink). But if the delegation in question is the only read delegation and is held by the client performing the operation, that's not really necessary. It's not always possible to prevent this in the NFSv4.0 case, because there's not always a way to determine which client an NFSv4.0 delegation came from. (In theory we could try to guess this from the transport layer, e.g., by assuming all traffic on a given TCP connection comes from the same client. But that's not really correct.) In the NFSv4.1 case the session layer always tells us the client. This patch should remove such self-conflicts in all cases where we can reliably determine the client from the compound. To do that we need to track "who" is performing a given (possibly lease-breaking) file operation. We're doing that by storing the information in the svc_rqst and using kthread_data() to map the current task back to a svc_rqst. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-03-16nfsd: Fix NFSv4 READ on RDMA when using readvChuck Lever1-0/+3
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 <chuck.lever@oracle.com>
2020-03-16sunrpc: Replace zero-length array with flexible-array memberGustavo A. R. Silva1-1/+1
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2019-04-24SUNRPC: Allow further customisation of RPC program registrationTrond Myklebust1-0/+15
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 <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-24SUNRPC: Add a callback to initialise server requestsTrond Myklebust1-0/+16
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 <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-24SUNRPC/nfs: Fix return value for nfs4_callback_compound()Trond Myklebust1-0/+2
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 <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-28sunrpc: replace svc_serv->sv_bc_xprt by boolean flagVasily Averin1-1/+1
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 <vvs@virtuozzo.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-12-28sunrpc: use-after-free in svc_process_common()Vasily Averin1-1/+4
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 <vvs@virtuozzo.com> Cc: stable@vger.kernel.org Fixes: 23c20ecd4475 ("NFS: callback up - users counting cleanup") Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09NFSD: Handle full-length symlinksChuck Lever1-1/+2
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 <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-08-09NFSD: Refactor the generic write vector fill helperChuck Lever1-0/+1
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 <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03NFSD: Clean up legacy NFS SYMLINK argument XDR decodersChuck Lever1-0/+2
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 <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03NFSD: Clean up legacy NFS WRITE argument XDR decodersChuck Lever1-0/+2
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 <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03svc: Report xprt dequeue latencyChuck Lever1-0/+1
Record the time between when a rqstp is enqueued on a transport and when it is dequeued. This includes how long the rqstp waits on the queue and how long it takes the kernel scheduler to wake a nfsd thread to service it. The svc_xprt_dequeue trace point is altered to include the number of microseconds between xprt_enqueue and xprt_dequeue. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03sunrpc: Report per-RPC execution statsChuck Lever1-0/+1
Introduce a mechanism to report the server-side execution latency of each RPC. The goal is to enable user space to filter the trace record for latency outliers, build histograms, etc. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-18Merge tag 'nfsd-4.15' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-0/+1
Pull nfsd updates from Bruce Fields: "Lots of good bugfixes, including: - fix a number of races in the NFSv4+ state code - fix some shutdown crashes in multiple-network-namespace cases - relax our 4.1 session limits; if you've an artificially low limit to the number of 4.1 clients that can mount simultaneously, try upgrading" * tag 'nfsd-4.15' of git://linux-nfs.org/~bfields/linux: (22 commits) SUNRPC: Improve ordering of transport processing nfsd: deal with revoked delegations appropriately svcrdma: Enqueue after setting XPT_CLOSE in completion handlers nfsd: use nfs->ns.inum as net ID rpc: remove some BUG()s svcrdma: Preserve CB send buffer across retransmits nfds: avoid gettimeofday for nfssvc_boot time fs, nfsd: convert nfs4_file.fi_ref from atomic_t to refcount_t fs, nfsd: convert nfs4_cntl_odstate.co_odcount from atomic_t to refcount_t fs, nfsd: convert nfs4_stid.sc_count from atomic_t to refcount_t lockd: double unregister of inetaddr notifiers nfsd4: catch some false session retries nfsd4: fix cached replies to solo SEQUENCE compounds sunrcp: make function _svc_create_xprt static SUNRPC: Fix tracepoint storage issues with svc_recv and svc_rqst_status nfsd: use ARRAY_SIZE nfsd: give out fewer session slots as limit approaches nfsd: increase DRC cache limit nfsd: remove unnecessary nofilehandle checks nfs_common: convert int to bool ...
2017-11-08SUNRPC: Improve ordering of transport processingTrond Myklebust1-0/+1
Since it can take a while before a specific thread gets scheduled, it is better to just implement a first come first served queue mechanism. That way, if a thread is already scheduled and is idle, it can pick up the work to do from the queue. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-25sunrpc: Const-ify struct sv_serv_opsChuck Lever1-3/+3
Close an attack vector by moving the arrays of per-server methods to read-only memory. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-07-12sunrpc: Allocate up to RPCSVC_MAXPAGES per svc_rqstChuck Lever1-1/+1
svcrdma needs 259 pages allocated to receive 1MB NFSv4.0 WRITE requests: - 1 page for the transport header and head iovec - 256 pages for the data payload - 1 page for the trailing GETATTR request (since NFSD XDR decoding does not look for a tail iovec, the GETATTR is stuck at the end of the rqstp->rq_arg.pages list) - 1 page for building the reply xdr_buf But RPCSVC_MAXPAGES is already 259 (on x86_64). The problem is that svc_alloc_arg never allocates that many pages. To address this: 1. The final element of rq_pages always points to NULL. To accommodate up to 259 pages in rq_pages, add an extra element to rq_pages for the array termination sentinel. 2. Adjust the calculation of "pages" to match how RPCSVC_MAXPAGES is calculated, so it can go up to 259. Bruce noted that the calculation assumes sv_max_mesg is a multiple of PAGE_SIZE, which might not always be true. I didn't change this assumption. 3. Change the loop boundaries to allow 259 pages to be allocated. Additional clean-up: WARN_ON_ONCE adds an extra conditional branch, which is basically never taken. And there's no need to dump the stack here because svc_alloc_arg has only one caller. Keeping that NULL "array termination sentinel"; there doesn't appear to be any code that depends on it, only code in nfsd_splice_actor() which needs the 259th element to be initialized to *something*. So it's possible we could just keep the array at 259 elements and drop that final NULL, but we're being conservative for now. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-06-28Merge tag 'v4.12-rc5' into nfsd treeJ. Bruce Fields1-1/+2
Update to get f0c3192ceee3 "virtio_net: lower limit on buffer size". That bug was interfering with my nfsd testing.
2017-05-16nfsd: Revert "nfsd: check for oversized NFSv2/v3 arguments"J. Bruce Fields1-1/+2
This reverts commit 51f567777799 "nfsd: check for oversized NFSv2/v3 arguments", which breaks support for NFSv3 ACLs. That patch was actually an earlier draft of a fix for the problem that was eventually fixed by e6838a29ecb "nfsd: check for oversized NFSv2/v3 arguments". But somehow I accidentally left this earlier draft in the branch that was part of my 2.12 pull request. Reported-by: Eryu Guan <eguan@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-05-15sunrpc: mark all struct svc_version instances as constChristoph Hellwig1-1/+1
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-15sunrpc: mark all struct svc_procinfo instances as constChristoph Hellwig1-2/+2
struct svc_procinfo contains function pointers, and marking it as constant avoids it being able to be used as an attach vector for code injections. Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15sunrpc: move pc_count out of struct svc_procinfoChristoph Hellwig1-1/+1
pc_count is the only writeable memeber of struct svc_procinfo, which is a good candidate to be const-ified as it contains function pointers. This patch moves it into out out struct svc_procinfo, and into a separate writable array that is pointed to by struct svc_version. Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15sunrpc: properly type pc_encode callbacksChristoph Hellwig1-1/+2
Drop the resp argument as it can trivially be derived from the rqstp argument. With that all functions now have the same prototype, and we can remove the unsafe casting to kxdrproc_t. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>