diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-01-07 08:36:45 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-01-07 08:36:45 -0800 |
commit | 4c9014f2ca7e5ecf8806e838be0f07aa1810c985 (patch) | |
tree | dd33fdebedf1ce6497737113e183f2a5d8bbca63 /net | |
parent | 5ce2955e04a80da7287dc12f32da7f870039bf8f (diff) | |
parent | ecf0eb9edbb607d74f74b73c14af8b43f3729528 (diff) | |
download | linux-4c9014f2ca7e5ecf8806e838be0f07aa1810c985.tar.bz2 |
Merge tag 'nfs-for-3.8-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
- Fix a permissions problem when opening NFSv4 files that only have the
exec bit set.
- Fix a couple of typos in pNFS (inverted logic), and the mount parsing
(missing pointer dereference).
- Work around a series of deadlock issues due to workqueues using
struct work_struct pointer address comparisons in the re-entrancy
tests. Ensure that we don't free struct work_struct prematurely if
our work function involves waiting for completion of other work items
(e.g. by calling rpc_shutdown_client).
- Revert the part of commit 168e4b3 that is causing unnecessary
warnings to be issued in the nfsd callback code.
* tag 'nfs-for-3.8-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
nfs: avoid dereferencing null pointer in initiate_bulk_draining
SUNRPC: Partial revert of commit 168e4b39d1afb79a7e3ea6c3bb246b4c82c6bdb9
NFS: Ensure that we free the rpc_task after read and write cleanups are done
SUNRPC: Ensure that we free the rpc_task after cleanups are done
nfs: fix null checking in nfs_get_option_str()
pnfs: Increase the refcount when LAYOUTGET fails the first time
NFS: Fix access to suid/sgid executables
Diffstat (limited to 'net')
-rw-r--r-- | net/sunrpc/clnt.c | 5 | ||||
-rw-r--r-- | net/sunrpc/sched.c | 27 |
2 files changed, 23 insertions, 9 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 822f020fa7f4..1915ffe598e3 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -610,11 +610,6 @@ EXPORT_SYMBOL_GPL(rpc_killall_tasks); */ void rpc_shutdown_client(struct rpc_clnt *clnt) { - /* - * To avoid deadlock, never call rpc_shutdown_client from a - * workqueue context! - */ - WARN_ON_ONCE(current->flags & PF_WQ_WORKER); might_sleep(); dprintk_rcu("RPC: shutting down %s client for %s\n", diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index d17a704aaf5f..b4133bd13915 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -934,16 +934,35 @@ struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data) return task; } +/* + * rpc_free_task - release rpc task and perform cleanups + * + * Note that we free up the rpc_task _after_ rpc_release_calldata() + * in order to work around a workqueue dependency issue. + * + * Tejun Heo states: + * "Workqueue currently considers two work items to be the same if they're + * on the same address and won't execute them concurrently - ie. it + * makes a work item which is queued again while being executed wait + * for the previous execution to complete. + * + * If a work function frees the work item, and then waits for an event + * which should be performed by another work item and *that* work item + * recycles the freed work item, it can create a false dependency loop. + * There really is no reliable way to detect this short of verifying + * every memory free." + * + */ static void rpc_free_task(struct rpc_task *task) { - const struct rpc_call_ops *tk_ops = task->tk_ops; - void *calldata = task->tk_calldata; + unsigned short tk_flags = task->tk_flags; + + rpc_release_calldata(task->tk_ops, task->tk_calldata); - if (task->tk_flags & RPC_TASK_DYNAMIC) { + if (tk_flags & RPC_TASK_DYNAMIC) { dprintk("RPC: %5u freeing task\n", task->tk_pid); mempool_free(task, rpc_task_mempool); } - rpc_release_calldata(tk_ops, calldata); } static void rpc_async_release(struct work_struct *work) |