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authorPaolo Valente <paolo.valente@linaro.org>2016-07-27 08:22:05 +0300
committerJens Axboe <axboe@fb.com>2016-08-04 23:19:16 +0300
commit20bd723ec6a3261df5e02250cd3a1fbb09a343f2 (patch)
treeb01a2118ba7e909481f91c28a5a81108251a842c /block
parentbfd279a868987e4bca7dc72a029e0fc50316d6df (diff)
downloadlinux-20bd723ec6a3261df5e02250cd3a1fbb09a343f2.tar.xz
block: add missing group association in bio-cloning functions
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> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
-rw-r--r--block/bio.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/block/bio.c b/block/bio.c
index 54ee3846c3a5..3f76a38a5e2d 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -583,6 +583,8 @@ 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);
@@ -687,6 +689,8 @@ integrity_clone:
}
}
+ bio_clone_blkcg_association(bio, bio_src);
+
return bio;
}
EXPORT_SYMBOL(bio_clone_bioset);
@@ -2004,6 +2008,17 @@ 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)