- 01 Mar, 2024 40 commits
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Chuck Lever authored
Reduce the doorbell and Send completion rates when sending RPC/RDMA replies that have Reply chunks. NFS READDIR procedures typically return their result in a Reply chunk, for example. Instead of calling ib_post_send() to post the Write WRs for the Reply chunk, and then calling it again to post the Send WR that conveys the transport header, chain the Write WRs to the Send WR and call ib_post_send() only once. Thanks to the Send Queue completion ordering rules, when the Send WR completes, that guarantees that Write WRs posted before it have also completed successfully. Thus all Write WRs for the Reply chunk can remain unsignaled. Instead of handling a Write completion and then a Send completion, only the Send completion is seen, and it handles clean up for both the Writes and the Send. Signed-off-by:Chuck Lever <chuck.lever@oracle.com>
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Chuck Lever authored
Since the RPC transaction's svc_rdma_send_ctxt will stay around for the duration of the RDMA Write operation, the write_info structure for the Reply chunk can reside in the request's svc_rdma_send_ctxt instead of being allocated separately. Signed-off-by: -
Chuck Lever authored
Eventually I'd like the server to post the reply's Send WR along with any Write WRs using only a single call to ib_post_send(), in order to reduce the NIC's doorbell rate. To do this, add an anchor for a WR chain to svc_rdma_send_ctxt, and refactor svc_rdma_send() to post this WR chain to the Send Queue. For the moment, the posted chain will continue to contain a single Send WR. Signed-off-by: -
Chuck Lever authored
Don't call ib_post_send() at all if the transport is already shutting down. Signed-off-by: -
Chuck Lever authored
In some error flow cases, svc_rdma_wc_send() releases @ctxt. Copy the sc_cid field in @ctxt to a stack variable in order to guarantee that the value is available after the ib_post_send() call. In case the new comment looks a little strange, this will be done with at least one more field in a subsequent patch. Signed-off-by: -
Chuck Lever authored
Ensure there is a wake-up when increasing sc_sq_avail. Likewise, if a wake-up is done, sc_sq_avail needs to be updated, otherwise the wait_event() conditional is never going to be met. Signed-off-by: -
Chuck Lever authored
rdma_rw_mr_factor() returns the smallest number of MRs needed to move a particular number of pages. svcrdma currently asks for the number of MRs needed to move RPCSVC_MAXPAGES (a little over one megabyte), as that is the number of pages in the largest r/wsize the server supports. This call assumes that the client's NIC can bundle a full one megabyte payload in a single rdma_segment. In fact, most NICs cannot handle a full megabyte with a single rkey / rdma_segment. Clients will typically split even a single Read chunk into many segments. The server needs one MR to read each rdma_segment in a Read chunk, and thus each one needs an rw_ctx. svcrdma has been vastly underestimating the number of rw_ctxs needed to handle 64 RPC requests with large Read chunks using small rdma_segments. Unfortunately there doesn't seem to be a good way to estimate this number without knowing the client NIC's capabilities. Even then, the client RPC/RDMA implementation is still free to split a chunk into smaller segments (for example, it might be using physical registration, which needs an rdma_segment per page). The best we can do for now is choose a number that will guarantee forward progress in the worst case (one page per segment). At some later point, we could add some mechanisms to make this much less of a problem: - Add a core API to add more rw_ctxs to an already-established QP - svcrdma could treat rw_ctx exhaustion as a temporary error and try again - Limit the number of Reads in flight Signed-off-by: -
Chuck Lever authored
rdma_create_qp() can modify cap.max_send_sges. Copy the new value to the svcrdma transport so it is bound by the new limit instead of the requested one. Signed-off-by: -
Chuck Lever authored
Check that svc_rdma_accept() is allocating an appropriate number of CQEs. Signed-off-by: -
Chuck Lever authored
Do as other ULPs already do: ensure there is an extra Receive WQE reserved for the tear-down drain WR. I haven't heard reports of problems but it can't hurt. Note that rq_depth is used to compute the Send Queue depth as well, so this fix should affect both the SQ and RQ. Signed-off-by: -
Jeff Layton authored
Alex helps co-maintain the DLM code and did some recent work to fix up how lockd and GFS2 work together. Add him as a Reviewer for file locking changes. Acked-by:
Alexander Aring <aahringo@redhat.com> Acked-by:
Jeff Layton <jlayton@kernel.org> Signed-off-by:
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Kunwu Chan authored
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Make the code cleaner and more readable. Signed-off-by:
Kunwu Chan <chentao@kylinos.cn> Signed-off-by:
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Kunwu Chan authored
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. And change cache name from 'nfsd_drc' to 'nfsd_cacherep'. Signed-off-by:
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Kunwu Chan authored
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by:
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Kunwu Chan authored
commit 0a31bd5f ("KMEM_CACHE(): simplify slab cache creation") introduces a new macro. Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by:
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NeilBrown authored
It is possible for free_blocked_lock() to be called twice concurrently, once from nfsd4_lock() and once from nfsd4_release_lockowner() calling remove_blocked_locks(). This is why a kref was added. It is perfectly safe for locks_delete_block() and kref_put() to be called in parallel as they use locking or atomicity respectively as protection. However locks_release_private() has no locking. It is safe for it to be called twice sequentially, but not concurrently. This patch moves that call from free_blocked_lock() where it could race with itself, to free_nbl() where it cannot. This will slightly delay the freeing of private info or release of the owner - but not by much. It is arguably more natural for this freeing to happen in free_nbl() where the structure itself is freed. This bug was found by code inspection - it has not been seen in practice. Fixes: 47446d74 ("nfsd4: add refcount for nfsd4_blocked_lock") Signed-off-by:
NeilBrown <neilb@suse.de> Signed-off-by:
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NeilBrown authored
When there is layout state on a filesystem that is being "unlocked" that is now revoked, which involves closing the nfsd_file and releasing the vfs lease. To avoid races, ->ls_file can now be accessed either: - under ->fi_lock for the state's sc_file or - under rcu_read_lock() if nfsd_file_get() is used. To support this, ->fence_client and nfsd4_cb_layout_fail() now take a second argument being the nfsd_file. Reviewed-by:
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NeilBrown authored
Revoking state through 'unlock_filesystem' now revokes any delegation states found. When the stateids are then freed by the client, the revoked stateids will be cleaned up correctly. As there is already support for revoking delegations, we build on that for admin-revoking. Reviewed-by:
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NeilBrown authored
Revoking state through 'unlock_filesystem' now revokes any open states found. When the stateids are then freed by the client, the revoked stateids will be cleaned up correctly. Possibly the related lock states should be revoked too, but a subsequent patch will do that for all lock state on the superblock. Reviewed-by:
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NeilBrown authored
Revoking state through 'unlock_filesystem' now revokes any lock states found. When the stateids are then freed by the client, the revoked stateids will be cleaned up correctly. Reviewed-by:
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NeilBrown authored
For NFSv4.1 and later the client easily discovers if there is any admin-revoked state and will then find and explicitly free it. For NFSv4.0 there is no such mechanism. The client can only find that state is admin-revoked if it tries to use that state, and there is no way for it to explicitly free the state. So the server must hold on to the stateid (at least) for an indefinite amount of time. A RELEASE_LOCKOWNER request might justify forgetting some of these stateids, as would the whole clients lease lapsing, but these are not reliable. This patch takes two approaches. Whenever a client uses an revoked stateid, that stateid is then discarded and will not be recognised again. This might confuse a client which expect to get NFS4ERR_ADMIN_REVOKED consistently once it get it at all, but should mostly work. Hopefully one error will lead to other resources being closed (e.g. process exits), which will result in more stateid being freed when a CLOSE attempt gets NFS4ERR_ADMIN_REVOKED. Also, any admin-revoked stateids that have been that way for more than one lease time are periodically revoke. No actual freeing of state happens in this patch. That will come in future patches which handle the different sorts of revoked state. Reviewed-by:
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NeilBrown authored
Add "admin-revoked" to the status information for any states that have been admin-revoked. This can be useful for confirming correct behaviour. Reviewed-by:
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NeilBrown authored
Change the "show" functions to show some content even if a file cannot be found. This is the case for admin-revoked state. This is primarily useful for debugging - to ensure states are being removed eventually. So change several seq_printf() to seq_puts(). Some of these are needed to keep checkpatch happy. Others were done for consistency. Reviewed-by:
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NeilBrown authored
The NFSv4 protocol allows state to be revoked by the admin and has error codes which allow this to be communicated to the client. This patch - introduces a new state-id status SC_STATUS_ADMIN_REVOKED which can be set on open, lock, or delegation state. - reports NFS4ERR_ADMIN_REVOKED when these are accessed - introduces a per-client counter of these states and returns SEQ4_STATUS_ADMIN_STATE_REVOKED when the counter is not zero. Decrements this when freeing any admin-revoked state. - introduces stub code to find all interesting states for a given superblock so they can be revoked via the 'unlock_filesystem' file in /proc/fs/nfsd/ No actual states are handled yet. Reviewed-by:
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NeilBrown authored
sc_type identifies the type of a state - open, lock, deleg, layout - and also the status of a state - closed or revoked. This is a bit untidy and could get worse when "admin-revoked" states are added. So clean it up. With this patch, the type is now all that is stored in sc_type. This is zero when the state is first added to ->cl_stateids (causing it to be ignored), and is then set appropriately once it is fully initialised. It is set under ->cl_lock to ensure atomicity w.r.t lookup. It is now never cleared. sc_type is still a bit-set even though at most one bit is set. This allows lookup functions to be given a bitmap of acceptable types. sc_type is now an unsigned short rather than char. There is no value in restricting to just 8 bits. All the constants now start SC_TYPE_ matching the field in which they are stored. Keeping the existing names and ensuring clear separation from non-type flags would have required something like NFS4_STID_TYPE_CLOSED which is cumbersome. The "NFS4" prefix is redundant was they only appear in NFS4 code, so remove that and change STID to SC to match the field. The status is stored in a separate unsigned short named "sc_status". It has two flags: SC_STATUS_CLOSED and SC_STATUS_REVOKED. CLOSED combines NFS4_CLOSED_STID, NFS4_CLOSED_DELEG_STID, and is used for SC_TYPE_LOCK and SC_TYPE_LAYOUT instead of setting the sc_type to zero. These flags are only ever set, never cleared. For deleg stateids they are set under the global state_lock. For open and lock stateids they are set under ->cl_lock. For layout stateids they are set under ->ls_lock nfs4_unhash_stid() has been removed, and we never set sc_type = 0. This was only used for LOCK and LAYOUT stids and they now use SC_STATUS_CLOSED. Also TRACE_DEFINE_NUM() calls for the various STID #define have been removed because these things are not enums, and so that call is incorrect. Reviewed-by:
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NeilBrown authored
NFS4_CLOSED_DELEG_STID and NFS4_REVOKED_DELEG_STID are similar in purpose. REVOKED is used for NFSv4.1 states which have been revoked because the lease has expired. CLOSED is used in other cases. The difference has two practical effects. 1/ REVOKED states are on the ->cl_revoked list 2/ REVOKED states result in nfserr_deleg_revoked from nfsd4_verify_open_stid() and nfsd4_validate_stateid while CLOSED states result in nfserr_bad_stid. Currently a state that is being revoked is first set to "CLOSED" in unhash_delegation_locked(), then possibly to "REVOKED" in revoke_delegation(), at which point it is added to the cl_revoked list. It is possible that a stateid test could see the CLOSED state which really should be REVOKED, and so return the wrong error code. So it is safest to remove this window of inconsistency. With this patch, unhash_delegation_locked() always sets the state correctly, and revoke_delegation() no longer changes the state. Also remove a redundant test on minorversion when NFS4_REVOKED_DELEG_STID is seen - it can only be seen when minorversion is non-zero. Reviewed-by:
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NeilBrown authored
Code like: WARN_ON(foo()) looks like an assertion and might not be expected to have any side effects. When testing if a function with side-effects fails a construct like if (foo()) WARN_ON(1); makes the intent more obvious. nfsd has several WARN_ON calls where the test has side effects, so it would be good to change them. These cases don't really need the WARN_ON. They have never failed in 8 years of usage so let's just remove the WARN_ON wrapper. Suggested-by: -
NeilBrown authored
The protocol for creating a new state in nfsd is to allocate the state leaving it largely uninitialised, add that state to the ->cl_stateids idr so as to reserve a state-id, then complete initialisation of the state and only set ->sc_type to non-zero once the state is fully initialised. If a state is found in the idr with ->sc_type == 0, it is ignored. The ->cl_lock lock is used to avoid races - it is held while checking sc_type during lookup, and held when a non-zero value is stored in ->sc_type. ... except... hash_delegation_locked() finalises the initialisation of a delegation state, but does NOT hold ->cl_lock. So this patch takes ->cl_lock at the appropriate time w.r.t other locks, and so ensures there are no races (which are extremely unlikely in any case). As ->fi_lock is often taken when ->cl_lock is held, we need to take ->cl_lock first of those two. Currently ->cl_lock and state_lock are never both taken at the same time. We need both for this patch so an arbitrary choice is needed concerning which to take first. As state_lock is more global, it might be more contended, so take it first. Reviewed-by:
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NeilBrown authored
As we do now support write delegations, this comment is unhelpful and misleading. Reported-by:
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Chuck Lever authored
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:
Benjamin Coddington <bcodding@redhat.com> Signed-off-by:
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Chuck Lever authored
bc_close() and bc_destroy now do something, so the comments are no longer correct. Commit 6221f1d9 ("SUNRPC: Fix backchannel RPC soft lockups") should have removed these. Reviewed-by:
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Chuck Lever authored
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:
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Chuck Lever authored
Convert a code comment into a real assertion. Reviewed-by:
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Chuck Lever authored
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Chuck Lever authored
svc_process_bc(), previously known as bc_svc_process(), was added in commit 4d6bbb62 ("nfs41: Backchannel bc_svc_process()") but there has never been a call site outside of the sunrpc.ko module. Reviewed-by:
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Chuck Lever authored
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: -
Chuck Lever authored
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: -
Chuck Lever authored
Improve observability of backchannel session operation. Reviewed-by:
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Chuck Lever authored
Add a trace point that records SEQ4_STATUS flags returned in an NFSv4.1 SEQUENCE response. SEQ4_STATUS flags report backchannel issues and changes to lease state to clients. Knowing what the server is reporting to clients is useful for debugging both configuration and operational issues in real time. For example, upcoming patches will enable server administrators to revoke parts of a client's lease; that revocation is indicated to the client when a subsequent SEQUENCE operation has one or more SEQ4_STATUS flags that are set. Sample trace records: nfsd-927 [006] 615.581821: nfsd_seq4_status: xid=0x095ded07 sessionid=65a032c3:b7845faf:00000001:00000000 status_flags=BACKCHANNEL_FAULT nfsd-927 [006] 615.588043: nfsd_seq4_status: xid=0x0a5ded07 sessionid=65a032c3:b7845faf:00000001:00000000 status_flags=BACKCHANNEL_FAULT nfsd-928 [003] 615.588448: nfsd_seq4_status: xid=0x0b5ded07 sessionid=65a032c3:b7845faf:00000001:00000000 status_flags=BACKCHANNEL_FAULT Reviewed-by:
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Chuck Lever authored
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: 7ba6cad6 ("nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors") Reviewed-by:
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