Patch "block: add missing group association in bio-cloning functions" has been added to the 4.7-stable tree
Subsystems (3)
This is a note to let you know that I've just added the patch titled
block: add missing group association in bio-cloning functions
to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
block-add-missing-group-association-in-bio-cloning-functions.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From
20bd723ec6a3261df5e02250cd3a1fbb09a343f2Mon Sep 17 00:00:00 2001
From: Paolo Valente <[email protected]>
Date: Wed, 27 Jul 2016 07:22:05 +0200
Subject: block: add missing group association in bio-cloning functions
From: Paolo Valente <[email protected]>
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.
--- block/bio.c | 15 +++++++++++++++ fs/btrfs/extent_io.c | 6 ------ include/linux/bio.h | 3 +++ 3 files changed, 18 insertions(+), 6 deletions(-)
block/bio.c +15 -0
@@ -579,6 +579,8 @@ void __bio_clone_fast(struct bio *bio, s 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 *b } } +/** +* 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 )
fs/btrfs/extent_io.c +0 -6
@@ -2696,12 +2696,6 @@ struct bio *btrfs_bio_clone(struct bio * 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; }
include/linux/bio.h +3 -0
@@ -527,11 +527,14 @@ extern unsigned int bvec_nr_vecs(unsigneint 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) { }#endif /* CONFIG_BLK_CGROUP */ #ifdef CONFIG_HIGHMEM
Patches currently in stable-queue which might be from [email protected] are
queue-4.7/block-add-missing-group-association-in-bio-cloning-functions.patch