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authorPaolo Valente <paolo.valente@linaro.org>2016-07-27 07:22:05 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-08-20 18:09:24 +0200
commit01daea925d04909561bf7c39c76e71d13ddcb2ec (patch)
tree759ad277622b38df355f404ad6907eb048d03a8d /block/bio.c
parent8660eadce2bafd16b2b2d0100190c5ac76519caf (diff)
block: add missing group association in bio-cloning functions
commit 20bd723ec6a3261df5e02250cd3a1fbb09a343f2 upstream. 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") 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/block/bio.c b/block/bio.c
index d4d144363250..46e2cc1d4016 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -584,6 +584,8 @@ 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);
@@ -689,6 +691,8 @@ integrity_clone:
}
}
+ bio_clone_blkcg_association(bio, bio_src);
+
return bio;
}
EXPORT_SYMBOL(bio_clone_bioset);
@@ -2014,6 +2018,17 @@ 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)