This is a note to let you know that I've just added the patch titled
dm space map metadata: fix ref counting bug when bootstrapping a new space map
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-space-map-metadata-fix-ref-counting-bug-when-bootstrapping-a-new-space-map.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 50dd842ad83b43bed71790efb31cfb2f6c05c9c1 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@xxxxxxxxxx>
Date: Wed, 9 Dec 2015 16:38:12 +0000
Subject: dm space map metadata: fix ref counting bug when bootstrapping a new space map
From: Joe Thornber <ejt@xxxxxxxxxx>
commit 50dd842ad83b43bed71790efb31cfb2f6c05c9c1 upstream.
When applying block operations (BOPs) do not remove them from the
uncommitted BOP ring-buffer until after they've been applied -- in case
we recurse.
Also, perform BOP_INC operation, in dm_sm_metadata_create() and
sm_metadata_extend(), in terms of the uncommitted BOP ring-buffer rather
than using direct calls to sm_ll_inc().
Signed-off-by: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/persistent-data/dm-space-map-metadata.c | 32 ++++++++++++++-------
1 file changed, 22 insertions(+), 10 deletions(-)
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -136,7 +136,7 @@ static int brb_push(struct bop_ring_buff
return 0;
}
-static int brb_pop(struct bop_ring_buffer *brb, struct block_op *result)
+static int brb_peek(struct bop_ring_buffer *brb, struct block_op *result)
{
struct block_op *bop;
@@ -147,6 +147,17 @@ static int brb_pop(struct bop_ring_buffe
result->type = bop->type;
result->block = bop->block;
+ return 0;
+}
+
+static int brb_pop(struct bop_ring_buffer *brb)
+{
+ struct block_op *bop;
+
+ if (brb_empty(brb))
+ return -ENODATA;
+
+ bop = brb->bops + brb->begin;
brb->begin = brb_next(brb, brb->begin);
return 0;
@@ -211,7 +222,7 @@ static int apply_bops(struct sm_metadata
while (!brb_empty(&smm->uncommitted)) {
struct block_op bop;
- r = brb_pop(&smm->uncommitted, &bop);
+ r = brb_peek(&smm->uncommitted, &bop);
if (r) {
DMERR("bug in bop ring buffer");
break;
@@ -220,6 +231,8 @@ static int apply_bops(struct sm_metadata
r = commit_bop(smm, &bop);
if (r)
break;
+
+ brb_pop(&smm->uncommitted);
}
return r;
@@ -681,7 +694,6 @@ static struct dm_space_map bootstrap_ops
static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
int r, i;
- enum allocation_event ev;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
dm_block_t old_len = smm->ll.nr_blocks;
@@ -703,11 +715,12 @@ static int sm_metadata_extend(struct dm_
* allocate any new blocks.
*/
do {
- for (i = old_len; !r && i < smm->begin; i++) {
- r = sm_ll_inc(&smm->ll, i, &ev);
- if (r)
- goto out;
- }
+ for (i = old_len; !r && i < smm->begin; i++)
+ r = add_bop(smm, BOP_INC, i);
+
+ if (r)
+ goto out;
+
old_len = smm->begin;
r = apply_bops(smm);
@@ -752,7 +765,6 @@ int dm_sm_metadata_create(struct dm_spac
{
int r;
dm_block_t i;
- enum allocation_event ev;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
smm->begin = superblock + 1;
@@ -780,7 +792,7 @@ int dm_sm_metadata_create(struct dm_spac
* allocated blocks that they were built from.
*/
for (i = superblock; !r && i < smm->begin; i++)
- r = sm_ll_inc(&smm->ll, i, &ev);
+ r = add_bop(smm, BOP_INC, i);
if (r)
return r;
Patches currently in stable-queue which might be from ejt@xxxxxxxxxx are
queue-3.14/dm-thin-restore-requested-error_if_no_space-setting-on-oods-to-write-transition.patch
queue-3.14/dm-space-map-metadata-fix-ref-counting-bug-when-bootstrapping-a-new-space-map.patch
queue-3.14/dm-btree-fix-bufio-buffer-leaks-in-dm_btree_del-error-path.patch
queue-3.14/dm-thin-metadata-fix-bug-when-taking-a-metadata-snapshot.patch
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