[patch v2 for-3.2] block: initialize request_queue's numa node duringallocation

From: David Rientjes
Date: Tue Nov 22 2011 - 20:14:35 EST


From: Mike Snitzer <snitzer@xxxxxxxxxx>

struct request_queue is allocated with __GFP_ZERO so its "node" field is
zero before initialization. This causes an oops if node 0 is offline in
the page allocator because its zonelists are not initialized. From Dave
Young's dmesg:

SRAT: Node 1 PXM 2 0-d0000000
SRAT: Node 1 PXM 2 100000000-330000000
SRAT: Node 0 PXM 1 330000000-630000000
Initmem setup node 1 0000000000000000-000000000affb000
...
Built 1 zonelists in Node order, mobility grouping on.
...
BUG: unable to handle kernel paging request at 0000000000001c08
IP: [<ffffffff8111c355>] __alloc_pages_nodemask+0xb5/0x870

and __alloc_pages_nodemask+0xb5 translates to a NULL pointer on
zonelist->_zonerefs.

The fix is to initialize q->node at the time of allocation so the correct
node is passed to the slab allocator later.

Since blk_init_allocated_queue_node() is no longer needed, merge it with
blk_init_allocated_queue().

[rientjes@xxxxxxxxxx: changelog, initializing q->node]
Cc: stable@xxxxxxxxxxxxxxx [2.6.37+]
Reported-by: Dave Young <dyoung@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
---
block/blk-core.c | 14 +++-----------
include/linux/blkdev.h | 3 ---
2 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -467,6 +467,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
q->backing_dev_info.state = 0;
q->backing_dev_info.capabilities = BDI_CAP_MAP_COPY;
q->backing_dev_info.name = "block";
+ q->node = node_id;

err = bdi_init(&q->backing_dev_info);
if (err) {
@@ -551,7 +552,7 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
if (!uninit_q)
return NULL;

- q = blk_init_allocated_queue_node(uninit_q, rfn, lock, node_id);
+ q = blk_init_allocated_queue(uninit_q, rfn, lock);
if (!q)
blk_cleanup_queue(uninit_q);

@@ -563,18 +564,9 @@ struct request_queue *
blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
spinlock_t *lock)
{
- return blk_init_allocated_queue_node(q, rfn, lock, -1);
-}
-EXPORT_SYMBOL(blk_init_allocated_queue);
-
-struct request_queue *
-blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn,
- spinlock_t *lock, int node_id)
-{
if (!q)
return NULL;

- q->node = node_id;
if (blk_init_free_list(q))
return NULL;

@@ -604,7 +596,7 @@ blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn,

return NULL;
}
-EXPORT_SYMBOL(blk_init_allocated_queue_node);
+EXPORT_SYMBOL(blk_init_allocated_queue);

int blk_get_queue(struct request_queue *q)
{
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -805,9 +805,6 @@ extern void blk_unprep_request(struct request *);
*/
extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
spinlock_t *lock, int node_id);
-extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
- request_fn_proc *,
- spinlock_t *, int node_id);
extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
request_fn_proc *, spinlock_t *);
--
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