2018-09-25 06:10:31

by Dongbo Cao

Subject: [PATCH 1/2] split original if-condition code into separate ones

to make it clearly to debug.

Signed-off-by: Dongbo Cao <[email protected]>
---
drivers/md/bcache/super.c | 81 +++++++++++++++++++++++++++++++--------
1 file changed, 66 insertions(+), 15 deletions(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index fa4058e4..0c0f6d8f 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2017,6 +2017,8 @@ static int cache_alloc(struct cache *ca)
size_t free;
size_t btree_buckets;
struct bucket *b;
+ int ret = -ENOMEM;
+ const char *err = NULL;

__module_get(THIS_MODULE);
kobject_init(&ca->kobj, &bch_cache_ktype);
@@ -2034,27 +2036,76 @@ static int cache_alloc(struct cache *ca)
*/
btree_buckets = ca->sb.njournal_buckets ?: 8;
free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
-
- if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets, GFP_KERNEL) ||
- !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
- !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) ||
- !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) ||
- !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) ||
- !init_heap(&ca->heap, free << 3, GFP_KERNEL) ||
- !(ca->buckets = vzalloc(array_size(sizeof(struct bucket),
- ca->sb.nbuckets))) ||
- !(ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t),
- prio_buckets(ca), 2),
- GFP_KERNEL)) ||
- !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)))
- return -ENOMEM;
+
+ if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets,
+ GFP_KERNEL)) {
+ err = "ca->free[RESERVE_BTREE] alloc failed";
+ goto err_btree_alloc;
+ }
+ if (!init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca),
+ GFP_KERNEL)) {
+ err = "ca->free[RESERVE_PRIO] alloc failed";
+ goto err_prio_alloc;
+ }
+ if (!init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL)) {
+ err = "ca->free[RESERVE_MOVINGGC] alloc failed";
+ goto err_movinggc_alloc;
+ }
+ if (!init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL)) {
+ err = "ca->free[RESERVE_NONE] alloc failed";
+ goto err_none_alloc;
+ }
+ if (!init_fifo(&ca->free_inc, free << 2, GFP_KERNEL)) {
+ err = "ca->free_inc alloc failed";
+ goto err_free_inc_alloc;
+ }
+ if (!init_heap(&ca->heap, free << 3, GFP_KERNEL)) {
+ err = "ca->heap alloc failed";
+ goto err_heap_alloc;
+ }
+ if (!(ca->buckets = vzalloc(array_size(sizeof(struct bucket),
+ ca->sb.nbuckets)))) {
+ err = "ca->buckets alloc failed";
+ goto err_buckets_alloc;
+ }
+ if (!(ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t),
+ prio_buckets(ca), 2),
+ GFP_KERNEL))) {
+ err = "ca->prio_buckets alloc failed";
+ goto err_prio_buckets_alloc;
+ }
+ if (!(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca))) {
+ err = "ca->disk_buckets alloc failed";
+ goto err_disk_buckets_alloc;
+ }

ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);

for_each_bucket(b, ca)
atomic_set(&b->pin, 0);
-
return 0;
+
+err_disk_buckets_alloc:
+ kfree(ca->prio_buckets);
+err_prio_buckets_alloc:
+ vfree(ca->buckets);
+err_buckets_alloc:
+ free_heap(&ca->heap);
+err_heap_alloc:
+ free_fifo(&ca->free_inc);
+err_free_inc_alloc:
+ free_fifo(&ca->free[RESERVE_NONE]);
+err_none_alloc:
+ free_fifo(&ca->free[RESERVE_MOVINGGC]);
+err_movinggc_alloc:
+ free_fifo(&ca->free[RESERVE_PRIO]);
+err_prio_alloc:
+ free_fifo(&ca->free[RESERVE_BTREE]);
+err_btree_alloc:
+ module_put(THIS_MODULE);
+ if (err)
+ pr_notice("error %s: %s", ca->cache_dev_name, err);
+ return ret;
}

static int register_cache(struct cache_sb *sb, struct page *sb_page,
--
2.17.1

2018-09-25 06:10:33

by Dongbo Cao

Subject: [PATCH 2/2] panic fix for making cache device

when the nbuckets of cache device is smaller than 1024, making cache device will trigger BUG_ON in kernel, add a condition to avoid this.

Signed-off-by: Dongbo Cao <[email protected]>
---
drivers/md/bcache/super.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 0c0f6d8f..47d122ed 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2036,7 +2036,12 @@ static int cache_alloc(struct cache *ca)
*/
btree_buckets = ca->sb.njournal_buckets ?: 8;
free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
-
+ if (!free) {
+ ret = -EPERM;
+ err = "ca->sb.nbuckets is too small";
+ goto err_free;
+ }
+
if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets,
GFP_KERNEL)) {
err = "ca->free[RESERVE_BTREE] alloc failed";
@@ -2102,6 +2107,7 @@ static int cache_alloc(struct cache *ca)
err_prio_alloc:
free_fifo(&ca->free[RESERVE_BTREE]);
err_btree_alloc:
+err_free:
module_put(THIS_MODULE);
if (err)
pr_notice("error %s: %s", ca->cache_dev_name, err);
@@ -2131,6 +2137,8 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
if (ret == -ENOMEM)
err = "cache_alloc(): -ENOMEM";
+ else if (ret == -EPERM)
+ err = "cache_alloc(): cache device is too small";
else
err = "cache_alloc(): unknown error";
goto err;
--
2.17.1

2018-09-25 12:41:35

by Coly Li

Subject: Re: [PATCH 1/2] split original if-condition code into separate ones

On 9/25/18 2:09 PM, Dongbo Cao wrote:
> to make it clearly to debug.
>
> Signed-off-by: Dongbo Cao <[email protected]>

The patch added to my for-next, with minor changes to fix checkpatch.pl
warnings.

Thanks.


Coly Li


> ---
> drivers/md/bcache/super.c | 81 +++++++++++++++++++++++++++++++--------
> 1 file changed, 66 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index fa4058e4..0c0f6d8f 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -2017,6 +2017,8 @@ static int cache_alloc(struct cache *ca)
> size_t free;
> size_t btree_buckets;
> struct bucket *b;
> + int ret = -ENOMEM;
> + const char *err = NULL;
>
> __module_get(THIS_MODULE);
> kobject_init(&ca->kobj, &bch_cache_ktype);
> @@ -2034,27 +2036,76 @@ static int cache_alloc(struct cache *ca)
> */
> btree_buckets = ca->sb.njournal_buckets ?: 8;
> free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
> -
> - if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets, GFP_KERNEL) ||
> - !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
> - !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) ||
> - !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) ||
> - !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) ||
> - !init_heap(&ca->heap, free << 3, GFP_KERNEL) ||
> - !(ca->buckets = vzalloc(array_size(sizeof(struct bucket),
> - ca->sb.nbuckets))) ||
> - !(ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t),
> - prio_buckets(ca), 2),
> - GFP_KERNEL)) ||
> - !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)))
> - return -ENOMEM;
> +
> + if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets,
> + GFP_KERNEL)) {
> + err = "ca->free[RESERVE_BTREE] alloc failed";
> + goto err_btree_alloc;
> + }
> + if (!init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca),
> + GFP_KERNEL)) {
> + err = "ca->free[RESERVE_PRIO] alloc failed";
> + goto err_prio_alloc;
> + }
> + if (!init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL)) {
> + err = "ca->free[RESERVE_MOVINGGC] alloc failed";
> + goto err_movinggc_alloc;
> + }
> + if (!init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL)) {
> + err = "ca->free[RESERVE_NONE] alloc failed";
> + goto err_none_alloc;
> + }
> + if (!init_fifo(&ca->free_inc, free << 2, GFP_KERNEL)) {
> + err = "ca->free_inc alloc failed";
> + goto err_free_inc_alloc;
> + }
> + if (!init_heap(&ca->heap, free << 3, GFP_KERNEL)) {
> + err = "ca->heap alloc failed";
> + goto err_heap_alloc;
> + }
> + if (!(ca->buckets = vzalloc(array_size(sizeof(struct bucket),
> + ca->sb.nbuckets)))) {
> + err = "ca->buckets alloc failed";
> + goto err_buckets_alloc;
> + }
> + if (!(ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t),
> + prio_buckets(ca), 2),
> + GFP_KERNEL))) {
> + err = "ca->prio_buckets alloc failed";
> + goto err_prio_buckets_alloc;
> + }
> + if (!(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca))) {
> + err = "ca->disk_buckets alloc failed";
> + goto err_disk_buckets_alloc;
> + }
>
> ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
>
> for_each_bucket(b, ca)
> atomic_set(&b->pin, 0);
> -
> return 0;
> +
> +err_disk_buckets_alloc:
> + kfree(ca->prio_buckets);
> +err_prio_buckets_alloc:
> + vfree(ca->buckets);
> +err_buckets_alloc:
> + free_heap(&ca->heap);
> +err_heap_alloc:
> + free_fifo(&ca->free_inc);
> +err_free_inc_alloc:
> + free_fifo(&ca->free[RESERVE_NONE]);
> +err_none_alloc:
> + free_fifo(&ca->free[RESERVE_MOVINGGC]);
> +err_movinggc_alloc:
> + free_fifo(&ca->free[RESERVE_PRIO]);
> +err_prio_alloc:
> + free_fifo(&ca->free[RESERVE_BTREE]);
> +err_btree_alloc:
> + module_put(THIS_MODULE);
> + if (err)
> + pr_notice("error %s: %s", ca->cache_dev_name, err);
> + return ret;
> }
>
> static int register_cache(struct cache_sb *sb, struct page *sb_page,

2018-09-25 12:42:38

by Coly Li

Subject: Re: [PATCH 2/2] panic fix for making cache device

On 9/25/18 2:09 PM, Dongbo Cao wrote:
> when the nbuckets of cache device is smaller than 1024, making cache device will trigger BUG_ON in kernel, add a condition to avoid this.
>
> Signed-off-by: Dongbo Cao <[email protected]>

This patch added to my for-next, with minor change to fix checkpatch.pl
warning.

Thanks.


Coly Li


> ---
> drivers/md/bcache/super.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index 0c0f6d8f..47d122ed 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -2036,7 +2036,12 @@ static int cache_alloc(struct cache *ca)
> */
> btree_buckets = ca->sb.njournal_buckets ?: 8;
> free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
> -
> + if (!free) {
> + ret = -EPERM;
> + err = "ca->sb.nbuckets is too small";
> + goto err_free;
> + }
> +
> if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets,
> GFP_KERNEL)) {
> err = "ca->free[RESERVE_BTREE] alloc failed";
> @@ -2102,6 +2107,7 @@ static int cache_alloc(struct cache *ca)
> err_prio_alloc:
> free_fifo(&ca->free[RESERVE_BTREE]);
> err_btree_alloc:
> +err_free:
> module_put(THIS_MODULE);
> if (err)
> pr_notice("error %s: %s", ca->cache_dev_name, err);
> @@ -2131,6 +2137,8 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
> blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
> if (ret == -ENOMEM)
> err = "cache_alloc(): -ENOMEM";
> + else if (ret == -EPERM)
> + err = "cache_alloc(): cache device is too small";
> else
> err = "cache_alloc(): unknown error";
> goto err;