On Wed, Jun 20, 2012 at 03:24:59PM -0400, Mike Snitzer wrote:
> If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create()
> fails, dm_tm_create_internal() would still return success even though it
> cleaned up all resources it was supposed to have created.
>
> Fix the space map checker code to return an appropriate ERR_PTR and have
> dm_tm_create_internal() check for it with IS_ERR.
>
I tested the patch and it works. It fails gracefully instead of segfaulting.
device-mapper: reload ioctl failed: Cannot allocate memory
I still do get waring though about large memory allocation. That's a
separate issue though.
Thanks
Vivek
> Reported-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/md/persistent-data/dm-space-map-checker.c | 24 ++++++++++----------
> .../md/persistent-data/dm-transaction-manager.c | 8 +++++-
> 2 files changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/md/persistent-data/dm-space-map-checker.c b/drivers/md/persistent-data/dm-space-map-checker.c
> index 50ed53b..6d7c832 100644
> --- a/drivers/md/persistent-data/dm-space-map-checker.c
> +++ b/drivers/md/persistent-data/dm-space-map-checker.c
> @@ -343,25 +343,25 @@ struct dm_space_map *dm_sm_checker_create(struct dm_space_map *sm)
> int r;
> struct sm_checker *smc;
>
> - if (!sm)
> - return NULL;
> + if (IS_ERR_OR_NULL(sm))
> + return ERR_PTR(-EINVAL);
>
> smc = kmalloc(sizeof(*smc), GFP_KERNEL);
> if (!smc)
> - return NULL;
> + return ERR_PTR(-ENOMEM);
>
> memcpy(&smc->sm, &ops_, sizeof(smc->sm));
> r = ca_create(&smc->old_counts, sm);
> if (r) {
> kfree(smc);
> - return NULL;
> + return ERR_PTR(r);
> }
>
> r = ca_create(&smc->counts, sm);
> if (r) {
> ca_destroy(&smc->old_counts);
> kfree(smc);
> - return NULL;
> + return ERR_PTR(r);
> }
>
> smc->real_sm = sm;
> @@ -371,7 +371,7 @@ struct dm_space_map *dm_sm_checker_create(struct dm_space_map *sm)
> ca_destroy(&smc->counts);
> ca_destroy(&smc->old_counts);
> kfree(smc);
> - return NULL;
> + return ERR_PTR(r);
> }
>
> r = ca_commit(&smc->old_counts, &smc->counts);
> @@ -379,7 +379,7 @@ struct dm_space_map *dm_sm_checker_create(struct dm_space_map *sm)
> ca_destroy(&smc->counts);
> ca_destroy(&smc->old_counts);
> kfree(smc);
> - return NULL;
> + return ERR_PTR(r);
> }
>
> return &smc->sm;
> @@ -391,25 +391,25 @@ struct dm_space_map *dm_sm_checker_create_fresh(struct dm_space_map *sm)
> int r;
> struct sm_checker *smc;
>
> - if (!sm)
> - return NULL;
> + if (IS_ERR_OR_NULL(sm))
> + return ERR_PTR(-EINVAL);
>
> smc = kmalloc(sizeof(*smc), GFP_KERNEL);
> if (!smc)
> - return NULL;
> + return ERR_PTR(-ENOMEM);
>
> memcpy(&smc->sm, &ops_, sizeof(smc->sm));
> r = ca_create(&smc->old_counts, sm);
> if (r) {
> kfree(smc);
> - return NULL;
> + return ERR_PTR(r);
> }
>
> r = ca_create(&smc->counts, sm);
> if (r) {
> ca_destroy(&smc->old_counts);
> kfree(smc);
> - return NULL;
> + return ERR_PTR(r);
> }
>
> smc->real_sm = sm;
> diff --git a/drivers/md/persistent-data/dm-transaction-manager.c b/drivers/md/persistent-data/dm-transaction-manager.c
> index 02bf78e..e5604b3 100644
> --- a/drivers/md/persistent-data/dm-transaction-manager.c
> +++ b/drivers/md/persistent-data/dm-transaction-manager.c
> @@ -347,8 +347,10 @@ static int dm_tm_create_internal(struct dm_block_manager *bm,
> }
>
> *sm = dm_sm_checker_create(inner);
> - if (!*sm)
> + if (IS_ERR(*sm)) {
> + r = PTR_ERR(*sm);
> goto bad2;
> + }
>
> } else {
> r = dm_bm_write_lock(dm_tm_get_bm(*tm), sb_location,
> @@ -367,8 +369,10 @@ static int dm_tm_create_internal(struct dm_block_manager *bm,
> }
>
> *sm = dm_sm_checker_create(inner);
> - if (!*sm)
> + if (IS_ERR(*sm)) {
> + r = PTR_ERR(*sm);
> goto bad2;
> + }
> }
>
> return 0;
> --
> 1.7.4.4
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