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| author | David Howells <dhowells@redhat.com> | 2016-04-07 17:23:03 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-11 15:34:40 -0400 |
| commit | 2f02f7aea7b6c9a9312846c006e076ae6ad026a4 (patch) | |
| tree | 5afe9c2ab7c1c0c56ea17cd72bd5895232aae07f /fs | |
| parent | c64a73d584cc344915baee1183c791c0d0c42d79 (diff) | |
| download | linux-2f02f7aea7b6c9a9312846c006e076ae6ad026a4.tar.gz linux-2f02f7aea7b6c9a9312846c006e076ae6ad026a4.tar.bz2 linux-2f02f7aea7b6c9a9312846c006e076ae6ad026a4.zip | |
afs: Wait for outstanding async calls before closing rxrpc socket
The afs filesystem needs to wait for any outstanding asynchronous calls
(such as FS.GiveUpCallBacks cleaning up the callbacks lodged with a server)
to complete before closing the AF_RXRPC socket when unloading the module.
This may occur if the module is removed too quickly after unmounting all
filesystems. This will produce an error report that looks like:
AFS: Assertion failed
1 == 0 is false
0x1 == 0x0 is false
------------[ cut here ]------------
kernel BUG at ../fs/afs/rxrpc.c:135!
...
RIP: 0010:[<ffffffffa004111c>] afs_close_socket+0xec/0x107 [kafs]
...
Call Trace:
[<ffffffffa004a160>] afs_exit+0x1f/0x57 [kafs]
[<ffffffff810c30a0>] SyS_delete_module+0xec/0x17d
[<ffffffff81610417>] entry_SYSCALL_64_fastpath+0x12/0x6b
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/afs/rxrpc.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c index b50642870a43..b4d337ad6e36 100644 --- a/fs/afs/rxrpc.c +++ b/fs/afs/rxrpc.c @@ -65,6 +65,12 @@ static void afs_async_workfn(struct work_struct *work) call->async_workfn(call); } +static int afs_wait_atomic_t(atomic_t *p) +{ + schedule(); + return 0; +} + /* * open an RxRPC socket and bind it to be a server for callback notifications * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT @@ -126,13 +132,16 @@ void afs_close_socket(void) { _enter(""); + wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t, + TASK_UNINTERRUPTIBLE); + _debug("no outstanding calls"); + sock_release(afs_socket); _debug("dework"); destroy_workqueue(afs_async_calls); ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0); - ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0); _leave(""); } @@ -178,8 +187,6 @@ static void afs_free_call(struct afs_call *call) { _debug("DONE %p{%s} [%d]", call, call->type->name, atomic_read(&afs_outstanding_calls)); - if (atomic_dec_return(&afs_outstanding_calls) == -1) - BUG(); ASSERTCMP(call->rxcall, ==, NULL); ASSERT(!work_pending(&call->async_work)); @@ -188,6 +195,9 @@ static void afs_free_call(struct afs_call *call) kfree(call->request); kfree(call); + + if (atomic_dec_and_test(&afs_outstanding_calls)) + wake_up_atomic_t(&afs_outstanding_calls); } /* |