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path: root/fs/nfsd/nfs4callback.c
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2025-06-12NFSD: Avoid corruption of a referring call listChuck Lever
The new code neglects to remove a freshly-allocated RCL from the callback's referring call list when no matching referring call is found. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202505171002.cE46sdj5-lkp@intel.com/ Fixes: 4f3c8d8c9e10 ("NFSD: Implement CB_SEQUENCE referring call lists") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-11NFSD: Implement CB_SEQUENCE referring call listsChuck Lever
We have yet to implement a mechanism in NFSD for resolving races between a server's reply and a related callback operation. For example, a CB_OFFLOAD callback can race with the matching COPY response. The client will not recognize the copy state ID in the CB_OFFLOAD callback until the COPY response arrives. Trond adds: > It is also needed for the same kind of race with delegation > recalls, layout recalls, CB_NOTIFY_DEVICEID and would also be > helpful (although not as strongly required) for CB_NOTIFY_LOCK. RFC 8881 Section 20.9.3 describes referring call lists this way: > The csa_referring_call_lists array is the list of COMPOUND > requests, identified by session ID, slot ID, and sequence ID. > These are requests that the client previously sent to the server. > These previous requests created state that some operation(s) in > the same CB_COMPOUND as the csa_referring_call_lists are > identifying. A session ID is included because leased state is tied > to a client ID, and a client ID can have multiple sessions. See > Section 2.10.6.3. Introduce the XDR infrastructure for populating the csa_referring_call_lists argument of CB_SEQUENCE. Subsequent patches will put the referring call list to use. Note that cb_sequence_enc_sz estimates that only zero or one rcl is included in each CB_SEQUENCE, but the new infrastructure can manage any number of referring calls. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: remove unneeded forward declaration of nfsd4_mark_cb_fault()Jeff Layton
This isn't needed. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: handle errors from rpc_call_async()Jeff Layton
It's possible for rpc_call_async() to fail (mainly due to memory allocation failure). If it does, there isn't much recourse other than to requeue the callback and try again later. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: move cb_need_restart flag into cb_flagsJeff Layton
Since there is now a cb_flags word, use a new NFSD4_CALLBACK_REQUEUE flag in that instead of a separate boolean. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: replace CB_GETATTR_BUSY with NFSD4_CALLBACK_RUNNINGJeff Layton
These flags serve essentially the same purpose and get set and cleared at the same time. Drop CB_GETATTR_BUSY and just use NFSD4_CALLBACK_RUNNING instead. For this to work, we must use clear_and_wake_up_bit(), but doing that on for other types of callbacks is wasteful. Declare a new NFSD4_CALLBACK_WAKE flag in cb_flags to indicate that wake_up is needed, and only set that for CB_GETATTRs. Also, make the wait use a TASK_UNINTERRUPTIBLE sleep. This is done in the context of an nfsd thread, and it should never need to deal with signals. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: prevent callback tasks running concurrentlyJeff Layton
The nfsd4_callback workqueue jobs exist to queue backchannel RPCs to rpciod. Because they run in different workqueue contexts, the rpc_task can run concurrently with the workqueue job itself, should it become requeued. This is problematic as there is no locking when accessing the fields in the nfsd4_callback. Add a new unsigned long to nfsd4_callback and declare a new NFSD4_CALLBACK_RUNNING flag to be set in it. When attempting to run a workqueue job, do a test_and_set_bit() on that flag first, and don't queue the workqueue job if it returns true. Clear NFSD4_CALLBACK_RUNNING in nfsd41_destroy_cb(). This also gives us a more reliable mechanism for handling queueing failures in codepaths where we have to take references under spinlocks. We can now do the test_and_set_bit on NFSD4_CALLBACK_RUNNING first, and only take references to the objects if that returns false. Most of the nfsd4_run_cb() callers are converted to use this new flag or the nfsd4_try_run_cb() wrapper. The main exception is the callback channel probe, which has its own synchronization. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10NFSD: Fix callback decoder status codesChuck Lever
fs/nfsd/nfs4callback.c implements a callback client. Thus its XDR decoders are decoding replies, not calls. NFS4ERR_BAD_XDR is an on-the-wire status code that reports that the client sent a corrupted RPC /call/. It's not used as the internal error code when a /reply/ can't be decoded, since that kind of failure is never reported to the sender of that RPC message. Instead, a reply decoder should return -EIO, as the reply decoders in the NFS client do. Fixes: 6487a13b5c6b ("NFSD: add support for CB_GETATTR callback") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: eliminate special handling of NFS4ERR_SEQ_MISORDEREDJeff Layton
On a SEQ_MISORDERED error, the current code will reattempt the call, but set the slot sequence ID to 1. I can find no mention of this remedy in the spec, and it seems potentially dangerous. It's possible that the last call was sent with seqid 1, and doing this will cause a retransmission of the reply. Drop this special handling, and always treat SEQ_MISORDERED like BADSLOT. Retry the call, but leak the slot so that it is no longer used. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: handle NFS4ERR_BADSLOT on CB_SEQUENCE betterJeff Layton
Currently it just restarts the call, without getting a new slot. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: when CB_SEQUENCE gets ESERVERFAULT don't increment seq_nrJeff Layton
ESERVERFAULT means that the server sent a successful and legitimate reply, but the session info didn't match what was expected. Don't increment the seq_nr in that case. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: only check RPC_SIGNALLED() when restarting rpc_taskJeff Layton
nfsd4_cb_sequence_done() currently checks RPC_SIGNALLED() when processing the compound and releasing the slot. If RPC_SIGNALLED() returns true, then that means that the client is going to be torn down. Don't check RPC_SIGNALLED() after processing a successful reply. Check it only before restarting the rpc_task. If it returns true, then requeue the callback instead of restarting the task. Also, handle rpc_restart_call() and rpc_restart_call_prepare() failures correctly, by requeueing the callback. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: always release slot when requeueing callbackJeff Layton
If the callback is going to be requeued to the workqueue, then release the slot. The callback client and session could change and the slot may no longer be valid after that point. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: lift NFSv4.0 handling out of nfsd4_cb_sequence_done()Jeff Layton
It's a bit strange to call nfsd4_cb_sequence_done() on a callback with no CB_SEQUENCE. Lift the handling of restarting a call into a new helper, and move the handling of NFSv4.0 into nfsd4_cb_done(). Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-03-10nfsd: prepare nfsd4_cb_sequence_done() for error handling reworkJeff Layton
There is only one case where we want to proceed with processing the rest of the CB_COMPOUND, and that's when the cb_seq_status is 0. Make the default return value be false, and only set it to true in that case. Rename the "need_restart" label to "requeue", to better indicate that it's being requeued to the workqueue. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-02-10NFSD: Fix CB_GETATTR status fixChuck Lever
Jeff says: Now that I look, 1b3e26a5ccbf is wrong. The patch on the ml was correct, but the one that got committed is different. It should be: status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status); if (unlikely(status || cb->cb_status)) If "status" is non-zero, decoding failed (usu. BADXDR), but we also want to bail out and not decode the rest of the call if the decoded cb_status is non-zero. That's not happening here, cb_seq_status has already been checked and is non-zero, so this ends up trying to decode the rest of the CB_GETATTR reply when it doesn't exist. Reported-by: Jeff Layton <jlayton@kernel.org> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219737 Fixes: 1b3e26a5ccbf ("NFSD: fix decoding in nfs4_xdr_dec_cb_getattr") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-02-10NFSD: fix hang in nfsd4_shutdown_callbackDai Ngo
If nfs4_client is in courtesy state then there is no point to send the callback. This causes nfsd4_shutdown_callback to hang since cl_cb_inflight is not 0. This hang lasts about 15 minutes until TCP notifies NFSD that the connection was dropped. This patch modifies nfsd4_run_cb_work to skip the RPC call if nfs4_client is in courtesy state. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Fixes: 66af25799940 ("NFSD: add courteous server support for thread with only delegation") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-01-21nfsd: add support for delegated timestampsJeff Layton
Add support for the delegated timestamps on write delegations. This allows the server to proxy timestamps from the delegation holder to other clients that are doing GETATTRs vs. the same inode. When OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS bit is set in the OPEN call, set the dl_type to the *_ATTRS_DELEG flavor of delegation. Add timespec64 fields to nfs4_cb_fattr and decode the timestamps into those. Vet those timestamps according to the delstid spec and update the inode attrs if necessary. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-01-21nfsd: fix handling of delegated change attr in CB_GETATTRJeff Layton
RFC8881, section 10.4.3 has some specific guidance as to how the delegated change attribute should be handled. We currently don't follow that guidance properly. In particular, when the file is modified, the server always reports the initial change attribute + 1. Section 10.4.3 however indicates that it should be incremented on every GETATTR request from other clients. Only request the change attribute until the file has been modified. If there is an outstanding delegation, then increment the cached change attribute on every GETATTR. Fixes: 6487a13b5c6b ("NFSD: add support for CB_GETATTR callback") Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-01-06NFSD: add cb opcode to WARN_ONCE on failed callbackOlga Kornievskaia
It helps to know what kind of callback happened that triggered the WARN_ONCE in nfsd4_cb_done() function in diagnosing what can set an uncommon state where both cb_status and tk_status are set at the same time. Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-01-06NFSD: fix decoding in nfs4_xdr_dec_cb_getattrOlga Kornievskaia
If a client were to send an error to a CB_GETATTR call, the code erronously continues to try decode past the error code. It ends up returning BAD_XDR error to the rpc layer and then in turn trigger a WARN_ONCE in nfsd4_cb_done() function. Fixes: 6487a13b5c6b ("NFSD: add support for CB_GETATTR callback") Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-01-06nfsd: use new wake_up_var interfaces.NeilBrown
The wake_up_var interface is fragile as barriers are sometimes needed. There are now new interfaces so that most wake-ups can use an interface that is guaranteed to have all barriers needed. This patch changes the wake up on cl_cb_inflight to use atomic_dec_and_wake_up(). It also changes the wake up on rp_locked to use store_release_wake_up(). This involves changing rp_locked from atomic_t to int. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-12-20nfsd: restore callback functionality for NFSv4.0NeilBrown
A recent patch inadvertently broke callbacks for NFSv4.0. In the 4.0 case we do not expect a session to be found but still need to call setup_callback_client() which will not try to dereference it. This patch moves the check for failure to find a session into the 4.1+ branch of setup_callback_client() Fixes: 1e02c641c3a4 ("NFSD: Prevent NULL dereference in nfsd4_process_cb_update()") Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: allow for up to 32 callback session slotsJeff Layton
nfsd currently only uses a single slot in the callback channel, which is proving to be a bottleneck in some cases. Widen the callback channel to a max of 32 slots (subject to the client's target_maxreqs value). Change the cb_holds_slot boolean to an integer that tracks the current slot number (with -1 meaning "unassigned"). Move the callback slot tracking info into the session. Add a new u32 that acts as a bitmap to track which slots are in use, and a u32 to track the latest callback target_slotid that the client reports. To protect the new fields, add a new per-session spinlock (the se_lock). Fix nfsd41_cb_get_slot to always search for the lowest slotid (using ffs()). Finally, convert the session->se_cb_seq_nr field into an array of ints and add the necessary handling to ensure that the seqids get reset when the slot table grows after shrinking. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Prevent NULL dereference in nfsd4_process_cb_update()Chuck Lever
@ses is initialized to NULL. If __nfsd4_find_backchannel() finds no available backchannel session, setup_callback_client() will try to dereference @ses and segfault. Fixes: dcbeaa68dbbd ("nfsd4: allow backchannel recovery") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: drop the ncf_cb_bmap fieldJeff Layton
This is always the same value, and in a later patch we're going to need to set bits in WORD2. We can simplify this code and save a little space in the delegation too. Just hardcode the bitmap in the callback encode function. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11NFSD: Prevent a potential integer overflowChuck Lever
If the tag length is >= U32_MAX - 3 then the "length + 4" addition can result in an integer overflow. Address this by splitting the decoding into several steps so that decode_cb_compound4res() does not have to perform arithmetic on the unsafe length value. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20nfsd: add more nfsd_cb tracepointsJeff Layton
Add some tracepoints in the callback client RPC operations. Also add a tracepoint to nfsd4_cb_getattr_done. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20nfsd: add more info to WARN_ON_ONCE on failed callbacksJeff Layton
Currently, you get the warning and stack trace, but nothing is printed about the relevant error codes. Add that in. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-05-06NFSD: Move callback_wq into struct nfs4_clientChuck Lever
Commit 883820366747 ("nfsd: update workqueue creation") made the callback_wq single-threaded, presumably to protect modifications of cl_cb_client. See documenting comment for nfsd4_process_cb_update(). However, cl_cb_client is per-lease. There's no other reason that all callback operations need to be dispatched via a single thread. The single threading here means all client callbacks can be blocked by a problem with one client. Change the NFSv4 callback client so it serializes per-lease instead of serializing all NFSv4 callback operations on the server. Reported-by: Dai Ngo <dai.ngo@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-25Merge tag 'nfsd-6.9-5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: - Revert some backchannel fixes that went into v6.9-rc * tag 'nfsd-6.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: Revert "NFSD: Convert the callback workqueue to use delayed_work" Revert "NFSD: Reschedule CB operations when backchannel rpc_clnt is shut down"
2024-04-23Revert "NFSD: Convert the callback workqueue to use delayed_work"Chuck Lever
This commit was a pre-requisite for commit c1ccfcf1a9bf ("NFSD: Reschedule CB operations when backchannel rpc_clnt is shut down"), which has already been reverted. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-23Revert "NFSD: Reschedule CB operations when backchannel rpc_clnt is shut down"Chuck Lever
The reverted commit attempted to enable NFSD to retransmit pending callback operations if an NFS client disconnects, but unintentionally introduces a hazardous behavior regression if the client becomes permanently unreachable while callback operations are still pending. A disconnect can occur due to network partition or if the NFS server needs to force the NFS client to retransmit (for example, if a GSS window under-run occurs). Reverting the commit will make NFSD behave the same as it did in v6.8 and before. Pending callback operations are permanently lost if the client connection is terminated before the client receives them. For some callback operations, this loss is not harmful. However, for CB_RECALL, the loss means a delegation might be revoked unnecessarily. For CB_OFFLOAD, pending COPY operations will never complete unless the NFS client subsequently sends an OFFLOAD_STATUS operation, which the Linux NFS client does not currently implement. These issues still need to be addressed somehow. Reported-by: Dai Ngo <dai.ngo@oracle.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=218735 Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-12Merge tag 'nfsd-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linuxLinus Torvalds
Pull nfsd updates from Chuck Lever: "The bulk of the patches for this release are optimizations, code clean-ups, and minor bug fixes. One new feature to mention is that NFSD administrators now have the ability to revoke NFSv4 open and lock state. NFSD's NFSv3 support has had this capability for some time. As always I am grateful to NFSD contributors, reviewers, and testers" * tag 'nfsd-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (75 commits) NFSD: Clean up nfsd4_encode_replay() NFSD: send OP_CB_RECALL_ANY to clients when number of delegations reaches its limit NFSD: Document nfsd_setattr() fill-attributes behavior nfsd: Fix NFSv3 atomicity bugs in nfsd_setattr() nfsd: Fix a regression in nfsd_setattr() NFSD: OP_CB_RECALL_ANY should recall both read and write delegations NFSD: handle GETATTR conflict with write delegation NFSD: add support for CB_GETATTR callback NFSD: Document the phases of CREATE_SESSION NFSD: Fix the NFSv4.1 CREATE_SESSION operation nfsd: clean up comments over nfs4_client definition svcrdma: Add Write chunk WRs to the RPC's Send WR chain svcrdma: Post WRs for Write chunks in svc_rdma_sendto() svcrdma: Post the Reply chunk and Send WR together svcrdma: Move write_info for Reply chunks into struct svc_rdma_send_ctxt svcrdma: Post Send WR chain svcrdma: Fix retry loop in svc_rdma_send() svcrdma: Prevent a UAF in svc_rdma_send() svcrdma: Fix SQ wake-ups svcrdma: Increase the per-transport rw_ctx count ...
2024-03-01NFSD: add support for CB_GETATTR callbackDai Ngo
Includes: . CB_GETATTR proc for nfs4_cb_procedures[] . XDR encoding and decoding function for CB_GETATTR request/reply . add nfs4_cb_fattr to nfs4_delegation for sending CB_GETATTR and store file attributes from client's reply. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Remove redundant cb_seq_status initializationChuck Lever
As far as I can see, setting cb_seq_status in nfsd4_init_cb() is superfluous because it is set again in nfsd4_cb_prepare(). Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Remove BUG_ON in nfsd4_process_cb_update()Chuck Lever
Don't kill the kworker thread, and don't panic while cl_lock is held. There's no need for scorching the earth here. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Replace comment with lockdep assertionChuck Lever
Convert a code comment into a real assertion. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Remove unused @reason argumentChuck Lever
Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Add callback operation lifetime trace pointsChuck Lever
Help observe the flow of callback operations. bc_shutdown() records exactly when the backchannel RPC client is destroyed and cl_cb_client is replaced with NULL. Examples include: nfsd-955 [004] 650.013997: nfsd_cb_queue: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try) kworker/u21:4-497 [004] 650.014050: nfsd_cb_seq_status: task:00000001@00000001 sessionid=65b3c5b8:f541f749:00000001:00000000 tk_status=-107 seq_status=1 kworker/u21:4-497 [004] 650.014051: nfsd_cb_restart: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff88810e39f400 (first try) kworker/u21:4-497 [004] 650.014066: nfsd_cb_queue: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff88810e39f400 (need restart) kworker/u16:0-10 [006] 650.065750: nfsd_cb_start: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UNKNOWN kworker/u16:0-10 [006] 650.065752: nfsd_cb_bc_update: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try) kworker/u16:0-10 [006] 650.065754: nfsd_cb_bc_shutdown: addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try) kworker/u16:0-10 [006] 650.065810: nfsd_cb_new_state: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=DOWN Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Rename nfsd_cb_state trace pointChuck Lever
Make it clear where backchannel state is updated. Example trace point output: kworker/u16:0-10 [006] 2800.080404: nfsd_cb_new_state: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UP nfsd-940 [003] 2800.478368: nfsd_cb_new_state: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UNKNOWN kworker/u16:0-10 [003] 2800.478828: nfsd_cb_new_state: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=DOWN kworker/u16:0-10 [005] 2802.039724: nfsd_cb_start: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UP kworker/u16:0-10 [005] 2810.611452: nfsd_cb_start: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=FAULT kworker/u16:0-10 [005] 2810.616832: nfsd_cb_start: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UNKNOWN kworker/u16:0-10 [005] 2810.616931: nfsd_cb_start: addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=DOWN Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Replace dprintks in nfsd4_cb_sequence_done()Chuck Lever
Improve observability of backchannel session operation. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Retransmit callbacks after client reconnectsChuck Lever
NFSv4.1 clients assume that if they disconnect, that will force the server to resend pending callback operations once a fresh connection has been established. Turns out NFSD has not been resending after reconnect. Fixes: 7ba6cad6c88f ("nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors") Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Reschedule CB operations when backchannel rpc_clnt is shut downChuck Lever
As part of managing a client disconnect, NFSD closes down and replaces the backchannel rpc_clnt. If a callback operation is pending when the backchannel rpc_clnt is shut down, currently nfsd4_run_cb_work() just discards that callback. But there are multiple cases to deal with here: o The client's lease is getting destroyed. Throw the CB away. o The client disconnected. It might be forcing a retransmit of CB operations, or it could have disconnected for other reasons. Reschedule the CB so it is retransmitted when the client reconnects. Since callback operations can now be rescheduled, ensure that cb_ops->prepare can be called only once by moving the cb_ops->prepare paragraph down to just before the rpc_call_async() call. Fixes: 2bbfed98a4d8 ("nfsd: Fix races between nfsd4_cb_release() and nfsd4_shutdown_callback()") Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Convert the callback workqueue to use delayed_workChuck Lever
Normally, NFSv4 callback operations are supposed to be sent to the client as soon as they are queued up. In a moment, I will introduce a recovery path where the server has to wait for the client to reconnect. We don't want a hard busy wait here -- the callback should be requeued to try again in several milliseconds. For now, convert nfsd4_callback from struct work_struct to struct delayed_work, and queue with a zero delay argument. This should avoid behavior changes for current operation. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01NFSD: Reset cb_seq_status after NFS4ERR_DELAYChuck Lever
I noticed that once an NFSv4.1 callback operation gets a NFS4ERR_DELAY status on CB_SEQUENCE and then the connection is lost, the callback client loops, resending it indefinitely. The switch arm in nfsd4_cb_sequence_done() that handles NFS4ERR_DELAY uses rpc_restart_call() to rearm the RPC state machine for the retransmit, but that path does not call the rpc_prepare_call callback again. Thus cb_seq_status is set to -10008 by the first NFS4ERR_DELAY result, but is never set back to 1 for the retransmits. nfsd4_cb_sequence_done() thinks it's getting nothing but a long series of CB_SEQUENCE NFS4ERR_DELAY replies. Fixes: 7ba6cad6c88f ("nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors") Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-02-05nfsd: adapt to breakup of struct file_lockJeff Layton
Most of the existing APIs have remained the same, but subsystems that access file_lock fields directly need to reach into struct file_lock_core now. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-42-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-01-07NFSv4, NFSD: move enum nfs_cb_opnum4 to include/linux/nfs4.hChenXiaoSong
Callback operations enum is defined in client and server, move it to common header file. Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Acked-by: Anna Schumaker <Anna.Schumaker@netapp.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-12-18NFSD: Revert 738401a9bd1ac34ccd5723d69640a4adbb1a4bc0Chuck Lever
There's nothing wrong with this commit, but this is dead code now that nothing triggers a CB_GETATTR callback. It can be re-introduced once the issues with handling conflicting GETATTRs are resolved. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16NFSD: add support for CB_GETATTR callbackDai Ngo
Includes: . CB_GETATTR proc for nfs4_cb_procedures[] . XDR encoding and decoding function for CB_GETATTR request/reply . add nfs4_cb_fattr to nfs4_delegation for sending CB_GETATTR and store file attributes from client's reply. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>