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authorNeilBrown <neilb@suse.de>2014-12-15 12:56:57 +1100
committerNeilBrown <neilb@suse.de>2015-02-04 08:35:52 +1100
commit64590f45ddc7147fa1968147a1f5b5c436b728fe (patch)
treec33e8ce09d739bac929e8ca943a253cb03cafd12 /drivers/md/md.h
parent5c675f83c68fbdf9c0e103c1090b06be747fa62c (diff)
downloadlinux-64590f45ddc7147fa1968147a1f5b5c436b728fe.tar.bz2
md: make merge_bvec_fn more robust in face of personality changes.
There is no locking around calls to merge_bvec_fn(), so it is possible that calls which coincide with a level (or personality) change could go wrong. So create a central dispatch point for these functions and use rcu_read_lock(). If the array is suspended, reject any merge that can be rejected. If not, we know it is safe to call the function. Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/md.h')
-rw-r--r--drivers/md/md.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/md/md.h b/drivers/md/md.h
index f2602280fac1..bee5b852c33f 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -499,6 +499,10 @@ struct md_personality
/* congested implements bdi.congested_fn().
* Will not be called while array is 'suspended' */
int (*congested)(struct mddev *mddev, int bits);
+ /* mergeable_bvec is use to implement ->merge_bvec_fn */
+ int (*mergeable_bvec)(struct mddev *mddev,
+ struct bvec_merge_data *bvm,
+ struct bio_vec *biovec);
};
struct md_sysfs_entry {