linux-toradex.git/fs/afs/vl_probe.c, branch v7.2-rc5

afs: Keep a record of the current fileserver endpoint state

2024-01-01T16:37:27+00:00

Keep a record of the current fileserver endpoint state, including the probe
state, and replace it when a new probe is started rather than just
squelching the old state and overwriting it.  Clearance of the old state
can cause a race if there's another thread also currently trying to
communicate with that server.

It appears that this race might be the culprit for some occasions where
kafs complains about invalid data in the RPC reply because the rotation
algorithm fell all the way through without actually issuing an RPC call and
the error return got filled in from the probe state (which has a zero error
recorded).  Whatever happens to be in the caller's reply buffer is then
taken as the response.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

afs: Dispatch vlserver probes in priority order

2024-01-01T16:37:27+00:00

When probing all the addresses for a volume location server, dispatch them
in order of descending priority to try and get back highest priority one
first.

Also add a tracepoint to show the transmission and completion of the
probes.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

afs: Fold the afs_addr_cursor struct in

2023-12-24T15:22:55+00:00

Fold the afs_addr_cursor struct into the afs_operation struct and the
afs_vl_cursor struct and fold its operations into their callers also.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

afs: Use peer + service_id as call address

2023-12-24T15:22:55+00:00

Use the rxrpc_peer plus the service ID as the call address instead of
passing in a sockaddr_srx down to rxrpc.  The peer record is obtained by
using rxrpc_kernel_get_peer().  This avoids the need to repeatedly look up
the peer and allows rxrpc to hold on to resources for it.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

afs: Simplify error handling

2023-12-24T15:22:53+00:00

Simplify error handling a bit by moving it from the afs_addr_cursor struct
to the afs_operation and afs_vl_cursor structs and using the error
prioritisation function for accumulating errors from multiple sources (AFS
tries to rotate between multiple fileservers, some of which may be
inaccessible or in some state of offlinedness).

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

afs: Rename addr_list::failed to probe_failed

2023-12-24T15:22:51+00:00

Rename the failed member of struct addr_list to probe_failed as it's
specifically related to probe failures.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc, afs: Allow afs to pin rxrpc_peer objects

2023-12-24T15:22:50+00:00

Change rxrpc's API such that:

 (1) A new function, rxrpc_kernel_lookup_peer(), is provided to look up an
     rxrpc_peer record for a remote address and a corresponding function,
     rxrpc_kernel_put_peer(), is provided to dispose of it again.

 (2) When setting up a call, the rxrpc_peer object used during a call is
     now passed in rather than being set up by rxrpc_connect_call().  For
     afs, this meenat passing it to rxrpc_kernel_begin_call() rather than
     the full address (the service ID then has to be passed in as a
     separate parameter).

 (3) A new function, rxrpc_kernel_remote_addr(), is added so that afs can
     get a pointer to the transport address for display purposed, and
     another, rxrpc_kernel_remote_srx(), to gain a pointer to the full
     rxrpc address.

 (4) The function to retrieve the RTT from a call, rxrpc_kernel_get_srtt(),
     is then altered to take a peer.  This now returns the RTT or -1 if
     there are insufficient samples.

 (5) Rename rxrpc_kernel_get_peer() to rxrpc_kernel_call_get_peer().

 (6) Provide a new function, rxrpc_kernel_get_peer(), to get a ref on a
     peer the caller already has.

This allows the afs filesystem to pin the rxrpc_peer records that it is
using, allowing faster lookups and pointer comparisons rather than
comparing sockaddr_rxrpc contents.  It also makes it easier to get hold of
the RTT.  The following changes are made to afs:

 (1) The addr_list struct's addrs[] elements now hold a peer struct pointer
     and a service ID rather than a sockaddr_rxrpc.

 (2) When displaying the transport address, rxrpc_kernel_remote_addr() is
     used.

 (3) The port arg is removed from afs_alloc_addrlist() since it's always
     overridden.

 (4) afs_merge_fs_addr4() and afs_merge_fs_addr6() do peer lookup and may
     now return an error that must be handled.

 (5) afs_find_server() now takes a peer pointer to specify the address.

 (6) afs_find_server(), afs_compare_fs_alists() and afs_merge_fs_addr[46]{}
     now do peer pointer comparison rather than address comparison.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

afs: Turn the afs_addr_list address array into an array of structs

2023-12-24T15:22:50+00:00

Turn the afs_addr_list address array into an array of structs, thereby
allowing per-address (such as RTT) info to be added.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

afs: Fix vlserver probe RTT handling

2023-06-16T21:43:41+00:00

In the same spirit as commit ca57f02295f1 ("afs: Fix fileserver probe
RTT handling"), don't rule out using a vlserver just because there
haven't been enough packets yet to calculate a real rtt.  Always set the
server's probe rtt from the estimate provided by rxrpc_kernel_get_srtt,
which is capped at 1 second.

This could lead to EDESTADDRREQ errors when accessing a cell for the
first time, even though the vl servers are known and have responded to a
probe.

Fixes: 1d4adfaf6574 ("rxrpc: Make rxrpc_kernel_get_srtt() indicate validity")
Signed-off-by: Marc Dionne 
Signed-off-by: David Howells 
cc: linux-afs@lists.infradead.org
Link: http://lists.infradead.org/pipermail/linux-afs/2023-June/006746.html
Signed-off-by: Linus Torvalds

afs: Don't use VL probe running state to make decisions outside probe code

2020-08-20T17:21:28+00:00

Don't use the running state for VL server probes to make decisions about
which server to use as the state is cleared at the start of a probe and
intermediate values might also be misleading.

Instead, add a separate 'latest known' rtt in the afs_vlserver struct and a
flag to indicate if the server is known to be responding and update these
as and when we know what to change them to.

Fixes: 3bf0fb6f33dd ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells