linux/fs/afs
David Howells 34fa47612b afs: Fix race in async call refcounting
There's a race between afs_make_call() and afs_wake_up_async_call() in the
case that an error is returned from rxrpc_kernel_send_data() after it has
queued the final packet.

afs_make_call() will try and clean up the mess, but the call state may have
been moved on thereby causing afs_process_async_call() to also try and to
delete the call.

Fix this by:

 (1) Getting an extra ref for an asynchronous call for the call itself to
     hold.  This makes sure the call doesn't evaporate on us accidentally
     and will allow the call to be retained by the caller in a future
     patch.  The ref is released on leaving afs_make_call() or
     afs_wait_for_call_to_complete().

 (2) In the event of an error from rxrpc_kernel_send_data():

     (a) Don't set the call state to AFS_CALL_COMPLETE until *after* the
     	 call has been aborted and ended.  This prevents
     	 afs_deliver_to_call() from doing anything with any notifications
     	 it gets.

     (b) Explicitly end the call immediately to prevent further callbacks.

     (c) Cancel any queued async_work and wait for the work if it's
     	 executing.  This allows us to be sure the race won't recur when we
     	 change the state.  We put the work queue's ref on the call if we
     	 managed to cancel it.

     (d) Put the call's ref that we got in (1).  This belongs to us as long
     	 as the call is in state AFS_CALL_CL_REQUESTING.

Fixes: 341f741f04 ("afs: Refcount the afs_call struct")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-17 15:17:28 +00:00
..
addr_list.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
afs_cm.h afs: support the CB.ProbeUuid RPC op 2008-04-29 08:06:26 -07:00
afs_fs.h afs: Prospectively look up extra files when doing a single lookup 2018-04-09 21:12:31 +01:00
afs_vl.h afs: Make use of the YFS service upgrade to fully support IPv6 2017-11-13 15:38:19 +00:00
afs.h afs: Expand data structure fields to support YFS 2018-10-24 00:41:08 +01:00
cache.c afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS 2018-10-24 00:41:08 +01:00
callback.c afs: Implement YFS support in the fs client 2018-10-24 00:41:08 +01:00
cell.c afs: Fix TTL on VL server and address lists 2018-10-24 00:41:07 +01:00
cmservice.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
dir_edit.c afs: Locally edit directory data for mkdir/create/unlink/... 2018-04-09 21:54:48 +01:00
dir.c afs: Use d_instantiate() rather than d_add() and don't d_drop() 2018-11-29 21:08:14 -05:00
dynroot.c afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS 2018-10-24 00:41:08 +01:00
file.c fs: don't open code lru_to_page() 2019-01-04 13:13:48 -08:00
flock.c afs: Fix key refcounting in file locking code 2019-01-17 15:17:28 +00:00
fs_probe.c fs/: remove caller signal_pending branch predictions 2019-01-04 13:13:48 -08:00
fsclient.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
inode.c afs: Fix key refcounting in file locking code 2019-01-17 15:17:28 +00:00
internal.h afs: Fix missing net error handling 2018-11-29 21:08:14 -05:00
Kconfig afs: Allow dumping of server cursor on operation failure 2018-10-24 00:41:09 +01:00
main.c afs: Fix cell proc list 2018-10-12 13:18:57 +02:00
Makefile afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
misc.c afs: Fix missing net error handling 2018-11-29 21:08:14 -05:00
mntpt.c afs: Add a couple of tracepoints to log I/O errors 2018-10-24 00:41:07 +01:00
netdevices.c afs: Implement network namespacing 2018-05-23 12:01:15 +01:00
proc.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
protocol_yfs.h afs: Set correct lock type for the yfs CreateFile 2019-01-10 17:12:05 +00:00
rotate.c afs: Fix missing net error handling 2018-11-29 21:08:14 -05:00
rxrpc.c afs: Fix race in async call refcounting 2019-01-17 15:17:28 +00:00
security.c afs: Fix callback handling 2018-10-24 00:41:09 +01:00
server_list.c afs: Use struct_size() in kzalloc() 2019-01-10 17:12:05 +00:00
server.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
super.c afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS 2018-10-24 00:41:08 +01:00
vl_list.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
vl_probe.c fs/: remove caller signal_pending branch predictions 2019-01-04 13:13:48 -08:00
vl_rotate.c afs: Fix missing net error handling 2018-11-29 21:08:14 -05:00
vlclient.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
volume.c afs: Probe multiple fileservers simultaneously 2018-10-24 00:41:09 +01:00
write.c afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS 2018-10-24 00:41:08 +01:00
xattr.c afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS 2018-10-24 00:41:08 +01:00
xdr_fs.h afs: Adjust the directory XDR structures 2018-04-09 21:54:48 +01:00
yfsclient.c afs: Set correct lock type for the yfs CreateFile 2019-01-10 17:12:05 +00:00