kernel/linux.git/include/linux/sunrpc/svc.h, branch v6.12.80

nfsd: don't use sv_nrthreads in connection limiting calculations.

2025-10-19T14:34:03+00:00

[ Upstream commit eccbbc7c00a5aae5e704d4002adfaf4c3fa4b30d ] The heuristic for limiting the number of incoming connections to nfsd currently uses sv_nrthreads - allowing more connections if more threads were configured. A future patch will allow number of threads to grow dynamically so that there will be no need to configure sv_nrthreads. So we need a different solution for limiting connections. It isn't clear what problem is solved by limiting connections (as mentioned in a code comment) but the most likely problem is a connection storm - many connections that are not doing productive work. These will be closed after about 6 minutes already but it might help to slow down a storm. This patch adds a per-connection flag XPT_PEER_VALID which indicates that the peer has presented a filehandle for which it has some sort of access. i.e the peer is known to be trusted in some way. We now only count connections which have NOT been determined to be valid. There should be relative few of these at any given time. If the number of non-validated peer exceed a limit - currently 64 - we close the oldest non-validated peer to avoid having too many of these useless connections. Note that this patch significantly changes the meaning of the various configuration parameters for "max connections". The next patch will remove all of these. Signed-off-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Stable-dep-of: 898374fdd7f0 ("nfsd: unregister with rpcbind when deleting a transport") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

SUNRPC: replace program list with program array

2024-09-23T19:03:30+00:00

A service created with svc_create_pooled() can be given a linked list of programs and all of these will be served. Using a linked list makes it cumbersome when there are several programs that can be optionally selected with CONFIG settings. After this patch is applied, API consumers must use only svc_create_pooled() when creating an RPC service that listens for more than one RPC program. Signed-off-by: NeilBrown Signed-off-by: Mike Snitzer Acked-by: Chuck Lever Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

sunrpc: allow svc threads to fail initialisation cleanly

2024-09-20T23:31:03+00:00

If an svc thread needs to perform some initialisation that might fail, it has no good way to handle the failure. Before the thread can exit it must call svc_exit_thread(), but that requires the service mutex to be held. The thread cannot simply take the mutex as that could deadlock if there is a concurrent attempt to shut down all threads (which is unlikely, but not impossible). nfsd currently call svc_exit_thread() unprotected in the unlikely event that unshare_fs_struct() fails. We can clean this up by introducing svc_thread_init_status() by which an svc thread can report whether initialisation has succeeded. If it has, it continues normally into the action loop. If it has not, svc_thread_init_status() immediately aborts the thread. svc_start_kthread() waits for either of these to happen, and calls svc_exit_thread() (under the mutex) if the thread aborted. Signed-off-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: change sp_nrthreads from atomic_t to unsigned int.

2024-09-20T23:31:03+00:00

sp_nrthreads is only ever accessed under the service mutex nlmsvc_mutex nfs_callback_mutex nfsd_mutex so these is no need for it to be an atomic_t. The fact that all code using it is single-threaded means that we can simplify svc_pool_victim and remove the temporary elevation of sp_nrthreads. Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

SUNRPC: make various functions static, or not exported.

2024-09-01T14:04:56+00:00

Various functions are only used within the sunrpc module, and several are only use in the one file. So clean up: These are marked static, and any EXPORT is removed. svc_rcpb_setup() svc_rqst_alloc() svc_rqst_free() - also moved before first use svc_rpcbind_set_version() svc_drop() - also moved to svc.c These are now not EXPORTed, but are not static. svc_authenticate() svc_sock_update_bufs() Signed-off-by: NeilBrown Signed-off-by: Chuck Lever

sunrpc: refactor pool_mode setting code

2024-07-08T18:10:05+00:00

Allow the pool_mode setting code to be called from internal callers so we can call it from a new netlink op. Add a new svc_pool_map_get function to return the current setting. Change the existing module parameter handling to use the new interfaces under the hood. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: fix up the special handling of sv_nrpools == 1

2024-07-08T18:10:04+00:00

Only pooled services take a reference to the svc_pool_map. The sunrpc code has always used the sv_nrpools value to detect whether the service is pooled. The problem there is that nfsd is a pooled service, but when it's running in "global" pool_mode, it doesn't take a reference to the pool map because it has a sv_nrpools value of 1. This means that we have two separate codepaths for starting the server, depending on whether it's pooled or not. Fix this by adding a new flag to the svc_serv, that indicates whether the serv is pooled. With this we can have the nfsd service unconditionally take a reference, regardless of pool_mode. Note that this is a behavior change for /sys/module/sunrpc/parameters/pool_mode. Usually this file does not allow you to change the pool-mode while there are nfsd threads running, but if the pool-mode is "global" it's allowed. My assumption is that this is a bug, since it probably should never have worked this way. This patch changes the behavior such that you get back EBUSY even when nfsd is running in global mode. I think this is more reasonable behavior, and given that most people set this today using the module parameter, it's doubtful anyone will notice. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: remove ->pg_stats from svc_program

2024-03-01T14:12:09+00:00

Now that this isn't used anywhere, remove it. Signed-off-by: Josef Bacik Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

sunrpc: pass in the sv_stats struct through svc_create_pooled

2024-03-01T14:12:08+00:00

Since only one service actually reports the rpc stats there's not much of a reason to have a pointer to it in the svc_program struct. Adjust the svc_create_pooled function to take the sv_stats as an argument and pass the struct through there as desired instead of getting it from the svc_program->pg_stats. Signed-off-by: Josef Bacik Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

Merge tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

2024-01-11T00:13:57+00:00

Pull nfs client updates from Anna Schumaker: "New Features: - Always ask for type with READDIR - Remove nfs_writepage() Bugfixes: - Fix a suspicious RCU usage warning - Fix a blocklayoutdriver reference leak - Fix the block driver's calculation of layoutget size - Fix handling NFS4ERR_RETURNCONFLICT - Fix _xprt_switch_find_current_entry() - Fix v4.1 backchannel request timeouts - Don't add zero-length pnfs block devices - Use the parent cred in nfs_access_login_time() Cleanups: - A few improvements when dealing with referring calls from the server - Clean up various unused variables, struct fields, and function calls - Various tracepoint improvements" * tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (21 commits) NFSv4.1: Use the nfs_client's rpc timeouts for backchannel SUNRPC: Fixup v4.1 backchannel request timeouts rpc_pipefs: Replace one label in bl_resolve_deviceid() nfs: Remove writepage NFS: drop unused nfs_direct_req bytes_left pNFS: Fix the pnfs block driver's calculation of layoutget size nfs: print fileid in lookup tracepoints nfs: rename the nfs_async_rename_done tracepoint nfs: add new tracepoint at nfs4 revalidate entry point SUNRPC: fix _xprt_switch_find_current_entry logic NFSv4.1/pnfs: Ensure we handle the error NFS4ERR_RETURNCONFLICT NFSv4.1: if referring calls are complete, trust the stateid argument NFSv4: Track the number of referring calls in struct cb_process_state NFS: Use parent's objective cred in nfs_access_login_time() NFSv4: Always ask for type with READDIR pnfs/blocklayout: Don't add zero-length pnfs_block_dev blocklayoutdriver: Fix reference leak of pnfs_device_node SUNRPC: Fix a suspicious RCU usage warning SUNRPC: Create a helper function for accessing the rpc_clnt's xprt_switch SUNRPC: Remove unused function rpc_clnt_xprt_switch_put() ...