| Message ID | 1469549700-9732-1-git-send-email-paolo.valente@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi,
[auto build test WARNING on block/for-next]
[also build test WARNING on v4.7 next-20160726]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Paolo-Valente/block-add-missing-group-association-in-bio-cloning-functions/20160727-005044
base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
config: x86_64-randconfig-x015-201630 (attached as .config)
compiler: gcc-6 (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
In file included from block/bio.c:20:0:
include/linux/bio.h: In function 'bio_clone_blkcg_association':
>> include/linux/bio.h:480:30: warning: 'return' with a value, in function returning void
struct bio *src) { return 0; }
^
include/linux/bio.h:479:20: note: declared here
static inline void bio_clone_blkcg_association(struct bio *dst,
^~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/return +480 include/linux/bio.h
464 void zero_fill_bio(struct bio *bio);
465 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
466 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
467 extern unsigned int bvec_nr_vecs(unsigned short idx);
468
469 #ifdef CONFIG_BLK_CGROUP
470 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
471 int bio_associate_current(struct bio *bio);
472 void bio_disassociate_task(struct bio *bio);
473 void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
474 #else /* CONFIG_BLK_CGROUP */
475 static inline int bio_associate_blkcg(struct bio *bio,
476 struct cgroup_subsys_state *blkcg_css) { return 0; }
477 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
478 static inline void bio_disassociate_task(struct bio *bio) { }
479 static inline void bio_clone_blkcg_association(struct bio *dst,
> 480 struct bio *src) { return 0; }
481 #endif /* CONFIG_BLK_CGROUP */
482
483 #ifdef CONFIG_HIGHMEM
484 /*
485 * remember never ever reenable interrupts between a bvec_kmap_irq and
486 * bvec_kunmap_irq!
487 */
488 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/block/bio.c b/block/bio.c index 0e4aa42..4623869 100644 --- a/block/bio.c +++ b/block/bio.c @@ -579,6 +579,8 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src) bio->bi_rw = bio_src->bi_rw; bio->bi_iter = bio_src->bi_iter; bio->bi_io_vec = bio_src->bi_io_vec; + + bio_clone_blkcg_association(bio, bio_src); } EXPORT_SYMBOL(__bio_clone_fast); @@ -684,6 +686,8 @@ integrity_clone: } } + bio_clone_blkcg_association(bio, bio_src); + return bio; } EXPORT_SYMBOL(bio_clone_bioset); @@ -2005,6 +2009,17 @@ void bio_disassociate_task(struct bio *bio) } } +/** + * bio_clone_blkcg_association - clone blkcg association from src to dst bio + * @dst: destination bio + * @src: source bio + */ +void bio_clone_blkcg_association(struct bio *dst, struct bio *src) +{ + if (src->bi_css) + WARN_ON(bio_associate_blkcg(dst, src->bi_css)); +} + #endif /* CONFIG_BLK_CGROUP */ static void __init biovec_init_slabs(void) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 75533ad..92fe3f8 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2696,12 +2696,6 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask) btrfs_bio->csum = NULL; btrfs_bio->csum_allocated = NULL; btrfs_bio->end_io = NULL; - -#ifdef CONFIG_BLK_CGROUP - /* FIXME, put this into bio_clone_bioset */ - if (bio->bi_css) - bio_associate_blkcg(new, bio->bi_css); -#endif } return new; } diff --git a/include/linux/bio.h b/include/linux/bio.h index 9faebf7..c9403b7 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -527,11 +527,14 @@ extern unsigned int bvec_nr_vecs(unsigned short idx); int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css); int bio_associate_current(struct bio *bio); void bio_disassociate_task(struct bio *bio); +void bio_clone_blkcg_association(struct bio *dst, struct bio *src); #else /* CONFIG_BLK_CGROUP */ static inline int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { return 0; } static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } static inline void bio_disassociate_task(struct bio *bio) { } +static inline void bio_clone_blkcg_association(struct bio *dst, + struct bio *src) { return 0; } #endif /* CONFIG_BLK_CGROUP */ #ifdef CONFIG_HIGHMEM
When a bio is cloned, the newly created bio must be associated with the same blkcg as the original bio (if BLK_CGROUP is enabled). If this operation is not performed, then the new bio is not associated with any group, and the group of the current task is returned when the group of the bio is requested. Depending on the cloning frequency, this may cause a large percentage of the bios belonging to a given group to be treated as if belonging to other groups (in most cases as if belonging to the root group). The expected group isolation may thereby be broken. This commit adds the missing association in bio-cloning functions. Fixes: da2f0f74cf7d ("Btrfs: add support for blkio controllers") Cc: stable@vger.kernel.org # v4.3+ Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Reviewed-by: Nikolay Borisov <kernel@kyup.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> --- block/bio.c | 15 +++++++++++++++ fs/btrfs/extent_io.c | 6 ------ include/linux/bio.h | 3 +++ 3 files changed, 18 insertions(+), 6 deletions(-)