diff options
author | Mikulas Patocka <mpatocka@redhat.com> | 2019-10-02 06:14:17 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-06 12:42:51 +0100 |
commit | cd83f10afd9d7c0e37b46b8d0c261a31499db210 (patch) | |
tree | 405502840439bf936e9abe1979dcb9677612ed52 /drivers/md | |
parent | f62931ec9ded76f0f16359d7b58dbb271326b4ac (diff) |
dm snapshot: introduce account_start_copy() and account_end_copy()
[ Upstream commit a2f83e8b0c82c9500421a26c49eb198b25fcdea3 ]
This simple refactoring moves code for modifying the semaphore cow_count
into separate functions to prepare for changes that will extend these
methods to provide for a more sophisticated mechanism for COW
throttling.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/md')
-rw-r--r-- | drivers/md/dm-snap.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 8b1556e77a0a..a9575122a0c6 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -1399,6 +1399,16 @@ static void snapshot_dtr(struct dm_target *ti) kfree(s); } +static void account_start_copy(struct dm_snapshot *s) +{ + down(&s->cow_count); +} + +static void account_end_copy(struct dm_snapshot *s) +{ + up(&s->cow_count); +} + /* * Flush a list of buffers. */ @@ -1581,7 +1591,7 @@ static void copy_callback(int read_err, unsigned long write_err, void *context) } list_add(&pe->out_of_order_entry, lh); } - up(&s->cow_count); + account_end_copy(s); } /* @@ -1605,7 +1615,7 @@ static void start_copy(struct dm_snap_pending_exception *pe) dest.count = src.count; /* Hand over to kcopyd */ - down(&s->cow_count); + account_start_copy(s); dm_kcopyd_copy(s->kcopyd_client, &src, 1, &dest, 0, copy_callback, pe); } @@ -1625,7 +1635,7 @@ static void start_full_bio(struct dm_snap_pending_exception *pe, pe->full_bio = bio; pe->full_bio_end_io = bio->bi_end_io; - down(&s->cow_count); + account_start_copy(s); callback_data = dm_kcopyd_prepare_callback(s->kcopyd_client, copy_callback, pe); |