This is a note to let you know that I've just added the patch titled dm btree: add ref counting ops for the leaves of top level btrees to the 4.1-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-btree-add-ref-counting-ops-for-the-leaves-of-top-level-btrees.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b0dc3c8bc157c60b1d470163882be8c13e1950af Mon Sep 17 00:00:00 2001 From: Joe Thornber <ejt@xxxxxxxxxx> Date: Wed, 12 Aug 2015 15:12:09 +0100 Subject: dm btree: add ref counting ops for the leaves of top level btrees From: Joe Thornber <ejt@xxxxxxxxxx> commit b0dc3c8bc157c60b1d470163882be8c13e1950af upstream. When using nested btrees, the top leaves of the top levels contain block addresses for the root of the next tree down. If we shadow a shared leaf node the leaf values (sub tree roots) should be incremented accordingly. This is only an issue if there is metadata sharing in the top levels. Which only occurs if metadata snapshots are being used (as is possible with dm-thinp). And could result in a block from the thinp metadata snap being reused early, thus corrupting the thinp metadata snap. 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-btree-internal.h | 6 ++++ drivers/md/persistent-data/dm-btree-remove.c | 12 ++------ drivers/md/persistent-data/dm-btree-spine.c | 37 +++++++++++++++++++++++++ drivers/md/persistent-data/dm-btree.c | 7 ---- 4 files changed, 47 insertions(+), 15 deletions(-) --- a/drivers/md/persistent-data/dm-btree-internal.h +++ b/drivers/md/persistent-data/dm-btree-internal.h @@ -138,4 +138,10 @@ int lower_bound(struct btree_node *n, ui extern struct dm_block_validator btree_node_validator; +/* + * Value type for upper levels of multi-level btrees. + */ +extern void init_le64_type(struct dm_transaction_manager *tm, + struct dm_btree_value_type *vt); + #endif /* DM_BTREE_INTERNAL_H */ --- a/drivers/md/persistent-data/dm-btree-remove.c +++ b/drivers/md/persistent-data/dm-btree-remove.c @@ -544,14 +544,6 @@ static int remove_raw(struct shadow_spin return r; } -static struct dm_btree_value_type le64_type = { - .context = NULL, - .size = sizeof(__le64), - .inc = NULL, - .dec = NULL, - .equal = NULL -}; - int dm_btree_remove(struct dm_btree_info *info, dm_block_t root, uint64_t *keys, dm_block_t *new_root) { @@ -559,12 +551,14 @@ int dm_btree_remove(struct dm_btree_info int index = 0, r = 0; struct shadow_spine spine; struct btree_node *n; + struct dm_btree_value_type le64_vt; + init_le64_type(info->tm, &le64_vt); init_shadow_spine(&spine, info); for (level = 0; level < info->levels; level++) { r = remove_raw(&spine, info, (level == last_level ? - &info->value_type : &le64_type), + &info->value_type : &le64_vt), root, keys[level], (unsigned *)&index); if (r < 0) break; --- a/drivers/md/persistent-data/dm-btree-spine.c +++ b/drivers/md/persistent-data/dm-btree-spine.c @@ -249,3 +249,40 @@ int shadow_root(struct shadow_spine *s) { return s->root; } + +static void le64_inc(void *context, const void *value_le) +{ + struct dm_transaction_manager *tm = context; + __le64 v_le; + + memcpy(&v_le, value_le, sizeof(v_le)); + dm_tm_inc(tm, le64_to_cpu(v_le)); +} + +static void le64_dec(void *context, const void *value_le) +{ + struct dm_transaction_manager *tm = context; + __le64 v_le; + + memcpy(&v_le, value_le, sizeof(v_le)); + dm_tm_dec(tm, le64_to_cpu(v_le)); +} + +static int le64_equal(void *context, const void *value1_le, const void *value2_le) +{ + __le64 v1_le, v2_le; + + memcpy(&v1_le, value1_le, sizeof(v1_le)); + memcpy(&v2_le, value2_le, sizeof(v2_le)); + return v1_le == v2_le; +} + +void init_le64_type(struct dm_transaction_manager *tm, + struct dm_btree_value_type *vt) +{ + vt->context = tm; + vt->size = sizeof(__le64); + vt->inc = le64_inc; + vt->dec = le64_dec; + vt->equal = le64_equal; +} --- a/drivers/md/persistent-data/dm-btree.c +++ b/drivers/md/persistent-data/dm-btree.c @@ -667,12 +667,7 @@ static int insert(struct dm_btree_info * struct btree_node *n; struct dm_btree_value_type le64_type; - le64_type.context = NULL; - le64_type.size = sizeof(__le64); - le64_type.inc = NULL; - le64_type.dec = NULL; - le64_type.equal = NULL; - + init_le64_type(info->tm, &le64_type); init_shadow_spine(&spine, info); for (level = 0; level < (info->levels - 1); level++) { Patches currently in stable-queue which might be from ejt@xxxxxxxxxx are queue-4.1/dm-btree-add-ref-counting-ops-for-the-leaves-of-top-level-btrees.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html