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| author | NeilBrown | 2014-12-15 02:56:57 +0100 |
|---|---|---|
| committer | NeilBrown | 2015-02-03 22:35:52 +0100 |
| commit | 64590f45ddc7147fa1968147a1f5b5c436b728fe (patch) | |
| tree | c33e8ce09d739bac929e8ca943a253cb03cafd12 /drivers/md/md.h | |
| parent | md: make ->congested robust against personality changes. (diff) | |
| download | kernel-qcow2-linux-64590f45ddc7147fa1968147a1f5b5c436b728fe.tar.gz kernel-qcow2-linux-64590f45ddc7147fa1968147a1f5b5c436b728fe.tar.xz kernel-qcow2-linux-64590f45ddc7147fa1968147a1f5b5c436b728fe.zip | |
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.h | 4 |
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 { |