[PATCH 10/25] afs: Handle EIO from delivery function [ver #2]

From: David Howells
Date: Tue Oct 23 2018 - 23:38:13 EST

Fix afs_deliver_to_call() to handle -EIO being returned by the operation
delivery function, indicating that the call found itself in the wrong
state, by printing an error and aborting the call.

Currently, an assertion failure will occur. This can happen, say, if the
delivery function falls off the end without calling afs_extract_data() with
the want_more parameter set to false to collect the end of the Rx phase of
a call.

The assertion failure looks like:

AFS: Assertion failed
4 == 7 is false
0x4 == 0x7 is false
------------[ cut here ]------------
kernel BUG at fs/afs/rxrpc.c:462!

and is matched in the trace buffer by a line like:

kworker/7:3-3226 [007] ...1 85158.030203: afs_io_error: c=0003be0c r=-5 CM_REPLY

Fixes: 98bf40cd99fc ("afs: Protect call->state changes against signals")
Reported-by: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>

fs/afs/rxrpc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index a3904a8315de..947ae3ab389b 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -499,7 +499,6 @@ static void afs_deliver_to_call(struct afs_call *call)
case -EAGAIN:
goto out;
- case -EIO:
goto done;
@@ -508,6 +507,10 @@ static void afs_deliver_to_call(struct afs_call *call)
rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
abort_code, ret, "KIV");
goto local_abort;
+ case -EIO:
+ pr_err("kAFS: Call %u in bad state %u\n",
+ call->debug_id, state);
+ /* Fall through */
case -ENODATA:
case -EBADMSG: