From: David Rientjes <rientjes@xxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit c6c8fe79a83e1a03e5dd83d0bac178d6ba5ef30a upstream.
rpc_malloc() allocates with GFP_NOWAIT without making any attempt at
reclaim so it easily fails when low on memory. This ends up spamming the
kernel log:
SLAB: Unable to allocate memory on node 0 (gfp=0x4000)
cache: kmalloc-8192, object size: 8192, order: 1
node 0: slabs: 207/207, objs: 207/207, free: 0
rekonq: page allocation failure: order:1, mode:0x204000
CPU: 2 PID: 14321 Comm: rekonq Tainted: G O 3.15.0-rc3-12.gfc9498b-desktop+ #6
Hardware name: System manufacturer System Product Name/M4A785TD-V EVO, BIOS 2105 07/23/2010
0000000000000000 ffff880010ff17d0 ffffffff815e693c 0000000000204000
ffff880010ff1858 ffffffff81137bd2 0000000000000000 0000001000000000
ffff88011ffebc38 0000000000000001 0000000000204000 ffff88011ffea000
Call Trace:
[<ffffffff815e693c>] dump_stack+0x4d/0x6f
[<ffffffff81137bd2>] warn_alloc_failed+0xd2/0x140
[<ffffffff8113be19>] __alloc_pages_nodemask+0x7e9/0xa30
[<ffffffff811824a8>] kmem_getpages+0x58/0x140
[<ffffffff81183de6>] fallback_alloc+0x1d6/0x210
[<ffffffff81183be3>] ____cache_alloc_node+0x123/0x150
[<ffffffff81185953>] __kmalloc+0x203/0x490
[<ffffffffa06b0ee2>] rpc_malloc+0x32/0xa0 [sunrpc]
[<ffffffffa06a6999>] call_allocate+0xb9/0x170 [sunrpc]
[<ffffffffa06b19d8>] __rpc_execute+0x88/0x460 [sunrpc]
[<ffffffffa06b2da9>] rpc_execute+0x59/0xc0 [sunrpc]
[<ffffffffa06a932b>] rpc_run_task+0x6b/0x90 [sunrpc]
[<ffffffffa077b5c1>] nfs4_call_sync_sequence+0x51/0x80 [nfsv4]
[<ffffffffa077d45d>] _nfs4_do_setattr+0x1ed/0x280 [nfsv4]
[<ffffffffa0782a72>] nfs4_do_setattr+0x72/0x180 [nfsv4]
[<ffffffffa078334c>] nfs4_proc_setattr+0xbc/0x140 [nfsv4]
[<ffffffffa074a7e8>] nfs_setattr+0xd8/0x240 [nfs]
[<ffffffff811baa71>] notify_change+0x231/0x380
[<ffffffff8119cf5c>] chmod_common+0xfc/0x120
[<ffffffff8119df80>] SyS_chmod+0x40/0x90
[<ffffffff815f4cfd>] system_call_fastpath+0x1a/0x1f
...
If the allocation fails, simply return NULL and avoid spamming the kernel
log.
Reported-by: Marc Dietrich <marvin24@xxxxxx>
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
net/sunrpc/sched.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index ff3cc4bf4b24..5fa4850be6f0 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -831,7 +831,8 @@ static void rpc_async_schedule(struct work_struct *work)
* @size: requested byte size
*
* To prevent rpciod from hanging, this allocator never sleeps,
- * returning NULL if the request cannot be serviced immediately.
+ * returning NULL and suppressing warning if the request cannot be serviced
+ * immediately.
* The caller can arrange to sleep in a way that is safe for rpciod.
*
* Most requests are 'small' (under 2KiB) and can be serviced from a
@@ -844,7 +845,7 @@ static void rpc_async_schedule(struct work_struct *work)
void *rpc_malloc(struct rpc_task *task, size_t size)
{
struct rpc_buffer *buf;
- gfp_t gfp = GFP_NOWAIT;
+ gfp_t gfp = GFP_NOWAIT | __GFP_NOWARN;
if (RPC_IS_SWAPPER(task))
gfp |= __GFP_MEMALLOC;
--
2.2.2
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